diff --git a/vendor/go.etcd.io/bbolt/.gitignore b/vendor/go.etcd.io/bbolt/.gitignore
new file mode 100644
index 0000000..3bcd8cb
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/.gitignore
@@ -0,0 +1,5 @@
+*.prof
+*.test
+*.swp
+/bin/
+cover.out
diff --git a/vendor/go.etcd.io/bbolt/.travis.yml b/vendor/go.etcd.io/bbolt/.travis.yml
new file mode 100644
index 0000000..a60300c
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/.travis.yml
@@ -0,0 +1,17 @@
+language: go
+go_import_path: go.etcd.io/bbolt
+
+sudo: false
+
+go:
+- 1.11
+
+before_install:
+- go get -v honnef.co/go/tools/...
+- go get -v github.com/kisielk/errcheck
+
+script:
+- make fmt
+- make test
+- make race
+# - make errcheck
diff --git a/vendor/go.etcd.io/bbolt/LICENSE b/vendor/go.etcd.io/bbolt/LICENSE
new file mode 100644
index 0000000..004e77f
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/LICENSE
@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Ben Johnson
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/go.etcd.io/bbolt/Makefile b/vendor/go.etcd.io/bbolt/Makefile
new file mode 100644
index 0000000..2968aaa
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/Makefile
@@ -0,0 +1,38 @@
+BRANCH=`git rev-parse --abbrev-ref HEAD`
+COMMIT=`git rev-parse --short HEAD`
+GOLDFLAGS="-X main.branch $(BRANCH) -X main.commit $(COMMIT)"
+
+default: build
+
+race:
+	@TEST_FREELIST_TYPE=hashmap go test -v -race -test.run="TestSimulate_(100op|1000op)"
+	@echo "array freelist test"
+	@TEST_FREELIST_TYPE=array go test -v -race -test.run="TestSimulate_(100op|1000op)"
+
+fmt:
+	!(gofmt -l -s -d $(shell find . -name \*.go) | grep '[a-z]')
+
+# go get honnef.co/go/tools/simple
+gosimple:
+	gosimple ./...
+
+# go get honnef.co/go/tools/unused
+unused:
+	unused ./...
+
+# go get github.com/kisielk/errcheck
+errcheck:
+	@errcheck -ignorepkg=bytes -ignore=os:Remove go.etcd.io/bbolt
+
+test:
+	TEST_FREELIST_TYPE=hashmap go test -timeout 20m -v -coverprofile cover.out -covermode atomic
+	# Note: gets "program not an importable package" in out of path builds
+	TEST_FREELIST_TYPE=hashmap go test -v ./cmd/bbolt
+
+	@echo "array freelist test"
+
+	@TEST_FREELIST_TYPE=array go test -timeout 20m -v -coverprofile cover.out -covermode atomic
+	# Note: gets "program not an importable package" in out of path builds
+	@TEST_FREELIST_TYPE=array go test -v ./cmd/bbolt
+
+.PHONY: race fmt errcheck test gosimple unused
diff --git a/vendor/go.etcd.io/bbolt/README.md b/vendor/go.etcd.io/bbolt/README.md
new file mode 100644
index 0000000..e9989ef
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/README.md
@@ -0,0 +1,954 @@
+bbolt
+=====
+
+[![Go Report Card](https://goreportcard.com/badge/github.com/etcd-io/bbolt?style=flat-square)](https://goreportcard.com/report/github.com/etcd-io/bbolt)
+[![Coverage](https://codecov.io/gh/etcd-io/bbolt/branch/master/graph/badge.svg)](https://codecov.io/gh/etcd-io/bbolt)
+[![Build Status Travis](https://img.shields.io/travis/etcd-io/bboltlabs.svg?style=flat-square&&branch=master)](https://travis-ci.com/etcd-io/bbolt)
+[![Godoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](https://godoc.org/github.com/etcd-io/bbolt)
+[![Releases](https://img.shields.io/github/release/etcd-io/bbolt/all.svg?style=flat-square)](https://github.com/etcd-io/bbolt/releases)
+[![LICENSE](https://img.shields.io/github/license/etcd-io/bbolt.svg?style=flat-square)](https://github.com/etcd-io/bbolt/blob/master/LICENSE)
+
+bbolt is a fork of [Ben Johnson's][gh_ben] [Bolt][bolt] key/value
+store. The purpose of this fork is to provide the Go community with an active
+maintenance and development target for Bolt; the goal is improved reliability
+and stability. bbolt includes bug fixes, performance enhancements, and features
+not found in Bolt while preserving backwards compatibility with the Bolt API.
+
+Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas]
+[LMDB project][lmdb]. The goal of the project is to provide a simple,
+fast, and reliable database for projects that don't require a full database
+server such as Postgres or MySQL.
+
+Since Bolt is meant to be used as such a low-level piece of functionality,
+simplicity is key. The API will be small and only focus on getting values
+and setting values. That's it.
+
+[gh_ben]: https://github.com/benbjohnson
+[bolt]: https://github.com/boltdb/bolt
+[hyc_symas]: https://twitter.com/hyc_symas
+[lmdb]: http://symas.com/mdb/
+
+## Project Status
+
+Bolt is stable, the API is fixed, and the file format is fixed. Full unit
+test coverage and randomized black box testing are used to ensure database
+consistency and thread safety. Bolt is currently used in high-load production
+environments serving databases as large as 1TB. Many companies such as
+Shopify and Heroku use Bolt-backed services every day.
+
+## Project versioning
+
+bbolt uses [semantic versioning](http://semver.org).
+API should not change between patch and minor releases.
+New minor versions may add additional features to the API.
+
+## Table of Contents
+
+  - [Getting Started](#getting-started)
+    - [Installing](#installing)
+    - [Opening a database](#opening-a-database)
+    - [Transactions](#transactions)
+      - [Read-write transactions](#read-write-transactions)
+      - [Read-only transactions](#read-only-transactions)
+      - [Batch read-write transactions](#batch-read-write-transactions)
+      - [Managing transactions manually](#managing-transactions-manually)
+    - [Using buckets](#using-buckets)
+    - [Using key/value pairs](#using-keyvalue-pairs)
+    - [Autoincrementing integer for the bucket](#autoincrementing-integer-for-the-bucket)
+    - [Iterating over keys](#iterating-over-keys)
+      - [Prefix scans](#prefix-scans)
+      - [Range scans](#range-scans)
+      - [ForEach()](#foreach)
+    - [Nested buckets](#nested-buckets)
+    - [Database backups](#database-backups)
+    - [Statistics](#statistics)
+    - [Read-Only Mode](#read-only-mode)
+    - [Mobile Use (iOS/Android)](#mobile-use-iosandroid)
+  - [Resources](#resources)
+  - [Comparison with other databases](#comparison-with-other-databases)
+    - [Postgres, MySQL, & other relational databases](#postgres-mysql--other-relational-databases)
+    - [LevelDB, RocksDB](#leveldb-rocksdb)
+    - [LMDB](#lmdb)
+  - [Caveats & Limitations](#caveats--limitations)
+  - [Reading the Source](#reading-the-source)
+  - [Other Projects Using Bolt](#other-projects-using-bolt)
+
+## Getting Started
+
+### Installing
+
+To start using Bolt, install Go and run `go get`:
+
+```sh
+$ go get go.etcd.io/bbolt/...
+```
+
+This will retrieve the library and install the `bolt` command line utility into
+your `$GOBIN` path.
+
+
+### Importing bbolt
+
+To use bbolt as an embedded key-value store, import as:
+
+```go
+import bolt "go.etcd.io/bbolt"
+
+db, err := bolt.Open(path, 0666, nil)
+if err != nil {
+  return err
+}
+defer db.Close()
+```
+
+
+### Opening a database
+
+The top-level object in Bolt is a `DB`. It is represented as a single file on
+your disk and represents a consistent snapshot of your data.
+
+To open your database, simply use the `bolt.Open()` function:
+
+```go
+package main
+
+import (
+	"log"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+func main() {
+	// Open the my.db data file in your current directory.
+	// It will be created if it doesn't exist.
+	db, err := bolt.Open("my.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer db.Close()
+
+	...
+}
+```
+
+Please note that Bolt obtains a file lock on the data file so multiple processes
+cannot open the same database at the same time. Opening an already open Bolt
+database will cause it to hang until the other process closes it. To prevent
+an indefinite wait you can pass a timeout option to the `Open()` function:
+
+```go
+db, err := bolt.Open("my.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
+```
+
+
+### Transactions
+
+Bolt allows only one read-write transaction at a time but allows as many
+read-only transactions as you want at a time. Each transaction has a consistent
+view of the data as it existed when the transaction started.
+
+Individual transactions and all objects created from them (e.g. buckets, keys)
+are not thread safe. To work with data in multiple goroutines you must start
+a transaction for each one or use locking to ensure only one goroutine accesses
+a transaction at a time. Creating transaction from the `DB` is thread safe.
+
+Read-only transactions and read-write transactions should not depend on one
+another and generally shouldn't be opened simultaneously in the same goroutine.
+This can cause a deadlock as the read-write transaction needs to periodically
+re-map the data file but it cannot do so while a read-only transaction is open.
+
+
+#### Read-write transactions
+
+To start a read-write transaction, you can use the `DB.Update()` function:
+
+```go
+err := db.Update(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Inside the closure, you have a consistent view of the database. You commit the
+transaction by returning `nil` at the end. You can also rollback the transaction
+at any point by returning an error. All database operations are allowed inside
+a read-write transaction.
+
+Always check the return error as it will report any disk failures that can cause
+your transaction to not complete. If you return an error within your closure
+it will be passed through.
+
+
+#### Read-only transactions
+
+To start a read-only transaction, you can use the `DB.View()` function:
+
+```go
+err := db.View(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+You also get a consistent view of the database within this closure, however,
+no mutating operations are allowed within a read-only transaction. You can only
+retrieve buckets, retrieve values, and copy the database within a read-only
+transaction.
+
+
+#### Batch read-write transactions
+
+Each `DB.Update()` waits for disk to commit the writes. This overhead
+can be minimized by combining multiple updates with the `DB.Batch()`
+function:
+
+```go
+err := db.Batch(func(tx *bolt.Tx) error {
+	...
+	return nil
+})
+```
+
+Concurrent Batch calls are opportunistically combined into larger
+transactions. Batch is only useful when there are multiple goroutines
+calling it.
+
+The trade-off is that `Batch` can call the given
+function multiple times, if parts of the transaction fail. The
+function must be idempotent and side effects must take effect only
+after a successful return from `DB.Batch()`.
+
+For example: don't display messages from inside the function, instead
+set variables in the enclosing scope:
+
+```go
+var id uint64
+err := db.Batch(func(tx *bolt.Tx) error {
+	// Find last key in bucket, decode as bigendian uint64, increment
+	// by one, encode back to []byte, and add new key.
+	...
+	id = newValue
+	return nil
+})
+if err != nil {
+	return ...
+}
+fmt.Println("Allocated ID %d", id)
+```
+
+
+#### Managing transactions manually
+
+The `DB.View()` and `DB.Update()` functions are wrappers around the `DB.Begin()`
+function. These helper functions will start the transaction, execute a function,
+and then safely close your transaction if an error is returned. This is the
+recommended way to use Bolt transactions.
+
+However, sometimes you may want to manually start and end your transactions.
+You can use the `DB.Begin()` function directly but **please** be sure to close
+the transaction.
+
+```go
+// Start a writable transaction.
+tx, err := db.Begin(true)
+if err != nil {
+    return err
+}
+defer tx.Rollback()
+
+// Use the transaction...
+_, err := tx.CreateBucket([]byte("MyBucket"))
+if err != nil {
+    return err
+}
+
+// Commit the transaction and check for error.
+if err := tx.Commit(); err != nil {
+    return err
+}
+```
+
+The first argument to `DB.Begin()` is a boolean stating if the transaction
+should be writable.
+
+
+### Using buckets
+
+Buckets are collections of key/value pairs within the database. All keys in a
+bucket must be unique. You can create a bucket using the `DB.CreateBucket()`
+function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b, err := tx.CreateBucket([]byte("MyBucket"))
+	if err != nil {
+		return fmt.Errorf("create bucket: %s", err)
+	}
+	return nil
+})
+```
+
+You can also create a bucket only if it doesn't exist by using the
+`Tx.CreateBucketIfNotExists()` function. It's a common pattern to call this
+function for all your top-level buckets after you open your database so you can
+guarantee that they exist for future transactions.
+
+To delete a bucket, simply call the `Tx.DeleteBucket()` function.
+
+
+### Using key/value pairs
+
+To save a key/value pair to a bucket, use the `Bucket.Put()` function:
+
+```go
+db.Update(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	err := b.Put([]byte("answer"), []byte("42"))
+	return err
+})
+```
+
+This will set the value of the `"answer"` key to `"42"` in the `MyBucket`
+bucket. To retrieve this value, we can use the `Bucket.Get()` function:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	b := tx.Bucket([]byte("MyBucket"))
+	v := b.Get([]byte("answer"))
+	fmt.Printf("The answer is: %s\n", v)
+	return nil
+})
+```
+
+The `Get()` function does not return an error because its operation is
+guaranteed to work (unless there is some kind of system failure). If the key
+exists then it will return its byte slice value. If it doesn't exist then it
+will return `nil`. It's important to note that you can have a zero-length value
+set to a key which is different than the key not existing.
+
+Use the `Bucket.Delete()` function to delete a key from the bucket.
+
+Please note that values returned from `Get()` are only valid while the
+transaction is open. If you need to use a value outside of the transaction
+then you must use `copy()` to copy it to another byte slice.
+
+
+### Autoincrementing integer for the bucket
+By using the `NextSequence()` function, you can let Bolt determine a sequence
+which can be used as the unique identifier for your key/value pairs. See the
+example below.
+
+```go
+// CreateUser saves u to the store. The new user ID is set on u once the data is persisted.
+func (s *Store) CreateUser(u *User) error {
+    return s.db.Update(func(tx *bolt.Tx) error {
+        // Retrieve the users bucket.
+        // This should be created when the DB is first opened.
+        b := tx.Bucket([]byte("users"))
+
+        // Generate ID for the user.
+        // This returns an error only if the Tx is closed or not writeable.
+        // That can't happen in an Update() call so I ignore the error check.
+        id, _ := b.NextSequence()
+        u.ID = int(id)
+
+        // Marshal user data into bytes.
+        buf, err := json.Marshal(u)
+        if err != nil {
+            return err
+        }
+
+        // Persist bytes to users bucket.
+        return b.Put(itob(u.ID), buf)
+    })
+}
+
+// itob returns an 8-byte big endian representation of v.
+func itob(v int) []byte {
+    b := make([]byte, 8)
+    binary.BigEndian.PutUint64(b, uint64(v))
+    return b
+}
+
+type User struct {
+    ID int
+    ...
+}
+```
+
+### Iterating over keys
+
+Bolt stores its keys in byte-sorted order within a bucket. This makes sequential
+iteration over these keys extremely fast. To iterate over keys we'll use a
+`Cursor`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	c := b.Cursor()
+
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+The cursor allows you to move to a specific point in the list of keys and move
+forward or backward through the keys one at a time.
+
+The following functions are available on the cursor:
+
+```
+First()  Move to the first key.
+Last()   Move to the last key.
+Seek()   Move to a specific key.
+Next()   Move to the next key.
+Prev()   Move to the previous key.
+```
+
+Each of those functions has a return signature of `(key []byte, value []byte)`.
+When you have iterated to the end of the cursor then `Next()` will return a
+`nil` key.  You must seek to a position using `First()`, `Last()`, or `Seek()`
+before calling `Next()` or `Prev()`. If you do not seek to a position then
+these functions will return a `nil` key.
+
+During iteration, if the key is non-`nil` but the value is `nil`, that means
+the key refers to a bucket rather than a value.  Use `Bucket.Bucket()` to
+access the sub-bucket.
+
+
+#### Prefix scans
+
+To iterate over a key prefix, you can combine `Seek()` and `bytes.HasPrefix()`:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	c := tx.Bucket([]byte("MyBucket")).Cursor()
+
+	prefix := []byte("1234")
+	for k, v := c.Seek(prefix); k != nil && bytes.HasPrefix(k, prefix); k, v = c.Next() {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+#### Range scans
+
+Another common use case is scanning over a range such as a time range. If you
+use a sortable time encoding such as RFC3339 then you can query a specific
+date range like this:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume our events bucket exists and has RFC3339 encoded time keys.
+	c := tx.Bucket([]byte("Events")).Cursor()
+
+	// Our time range spans the 90's decade.
+	min := []byte("1990-01-01T00:00:00Z")
+	max := []byte("2000-01-01T00:00:00Z")
+
+	// Iterate over the 90's.
+	for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) <= 0; k, v = c.Next() {
+		fmt.Printf("%s: %s\n", k, v)
+	}
+
+	return nil
+})
+```
+
+Note that, while RFC3339 is sortable, the Golang implementation of RFC3339Nano does not use a fixed number of digits after the decimal point and is therefore not sortable.
+
+
+#### ForEach()
+
+You can also use the function `ForEach()` if you know you'll be iterating over
+all the keys in a bucket:
+
+```go
+db.View(func(tx *bolt.Tx) error {
+	// Assume bucket exists and has keys
+	b := tx.Bucket([]byte("MyBucket"))
+
+	b.ForEach(func(k, v []byte) error {
+		fmt.Printf("key=%s, value=%s\n", k, v)
+		return nil
+	})
+	return nil
+})
+```
+
+Please note that keys and values in `ForEach()` are only valid while
+the transaction is open. If you need to use a key or value outside of
+the transaction, you must use `copy()` to copy it to another byte
+slice.
+
+### Nested buckets
+
+You can also store a bucket in a key to create nested buckets. The API is the
+same as the bucket management API on the `DB` object:
+
+```go
+func (*Bucket) CreateBucket(key []byte) (*Bucket, error)
+func (*Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error)
+func (*Bucket) DeleteBucket(key []byte) error
+```
+
+Say you had a multi-tenant application where the root level bucket was the account bucket. Inside of this bucket was a sequence of accounts which themselves are buckets. And inside the sequence bucket you could have many buckets pertaining to the Account itself (Users, Notes, etc) isolating the information into logical groupings.
+
+```go
+
+// createUser creates a new user in the given account.
+func createUser(accountID int, u *User) error {
+    // Start the transaction.
+    tx, err := db.Begin(true)
+    if err != nil {
+        return err
+    }
+    defer tx.Rollback()
+
+    // Retrieve the root bucket for the account.
+    // Assume this has already been created when the account was set up.
+    root := tx.Bucket([]byte(strconv.FormatUint(accountID, 10)))
+
+    // Setup the users bucket.
+    bkt, err := root.CreateBucketIfNotExists([]byte("USERS"))
+    if err != nil {
+        return err
+    }
+
+    // Generate an ID for the new user.
+    userID, err := bkt.NextSequence()
+    if err != nil {
+        return err
+    }
+    u.ID = userID
+
+    // Marshal and save the encoded user.
+    if buf, err := json.Marshal(u); err != nil {
+        return err
+    } else if err := bkt.Put([]byte(strconv.FormatUint(u.ID, 10)), buf); err != nil {
+        return err
+    }
+
+    // Commit the transaction.
+    if err := tx.Commit(); err != nil {
+        return err
+    }
+
+    return nil
+}
+
+```
+
+
+
+
+### Database backups
+
+Bolt is a single file so it's easy to backup. You can use the `Tx.WriteTo()`
+function to write a consistent view of the database to a writer. If you call
+this from a read-only transaction, it will perform a hot backup and not block
+your other database reads and writes.
+
+By default, it will use a regular file handle which will utilize the operating
+system's page cache. See the [`Tx`](https://godoc.org/go.etcd.io/bbolt#Tx)
+documentation for information about optimizing for larger-than-RAM datasets.
+
+One common use case is to backup over HTTP so you can use tools like `cURL` to
+do database backups:
+
+```go
+func BackupHandleFunc(w http.ResponseWriter, req *http.Request) {
+	err := db.View(func(tx *bolt.Tx) error {
+		w.Header().Set("Content-Type", "application/octet-stream")
+		w.Header().Set("Content-Disposition", `attachment; filename="my.db"`)
+		w.Header().Set("Content-Length", strconv.Itoa(int(tx.Size())))
+		_, err := tx.WriteTo(w)
+		return err
+	})
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}
+```
+
+Then you can backup using this command:
+
+```sh
+$ curl http://localhost/backup > my.db
+```
+
+Or you can open your browser to `http://localhost/backup` and it will download
+automatically.
+
+If you want to backup to another file you can use the `Tx.CopyFile()` helper
+function.
+
+
+### Statistics
+
+The database keeps a running count of many of the internal operations it
+performs so you can better understand what's going on. By grabbing a snapshot
+of these stats at two points in time we can see what operations were performed
+in that time range.
+
+For example, we could start a goroutine to log stats every 10 seconds:
+
+```go
+go func() {
+	// Grab the initial stats.
+	prev := db.Stats()
+
+	for {
+		// Wait for 10s.
+		time.Sleep(10 * time.Second)
+
+		// Grab the current stats and diff them.
+		stats := db.Stats()
+		diff := stats.Sub(&prev)
+
+		// Encode stats to JSON and print to STDERR.
+		json.NewEncoder(os.Stderr).Encode(diff)
+
+		// Save stats for the next loop.
+		prev = stats
+	}
+}()
+```
+
+It's also useful to pipe these stats to a service such as statsd for monitoring
+or to provide an HTTP endpoint that will perform a fixed-length sample.
+
+
+### Read-Only Mode
+
+Sometimes it is useful to create a shared, read-only Bolt database. To this,
+set the `Options.ReadOnly` flag when opening your database. Read-only mode
+uses a shared lock to allow multiple processes to read from the database but
+it will block any processes from opening the database in read-write mode.
+
+```go
+db, err := bolt.Open("my.db", 0666, &bolt.Options{ReadOnly: true})
+if err != nil {
+	log.Fatal(err)
+}
+```
+
+### Mobile Use (iOS/Android)
+
+Bolt is able to run on mobile devices by leveraging the binding feature of the
+[gomobile](https://github.com/golang/mobile) tool. Create a struct that will
+contain your database logic and a reference to a `*bolt.DB` with a initializing
+constructor that takes in a filepath where the database file will be stored.
+Neither Android nor iOS require extra permissions or cleanup from using this method.
+
+```go
+func NewBoltDB(filepath string) *BoltDB {
+	db, err := bolt.Open(filepath+"/demo.db", 0600, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return &BoltDB{db}
+}
+
+type BoltDB struct {
+	db *bolt.DB
+	...
+}
+
+func (b *BoltDB) Path() string {
+	return b.db.Path()
+}
+
+func (b *BoltDB) Close() {
+	b.db.Close()
+}
+```
+
+Database logic should be defined as methods on this wrapper struct.
+
+To initialize this struct from the native language (both platforms now sync
+their local storage to the cloud. These snippets disable that functionality for the
+database file):
+
+#### Android
+
+```java
+String path;
+if (android.os.Build.VERSION.SDK_INT >=android.os.Build.VERSION_CODES.LOLLIPOP){
+    path = getNoBackupFilesDir().getAbsolutePath();
+} else{
+    path = getFilesDir().getAbsolutePath();
+}
+Boltmobiledemo.BoltDB boltDB = Boltmobiledemo.NewBoltDB(path)
+```
+
+#### iOS
+
+```objc
+- (void)demo {
+    NSString* path = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,
+                                                          NSUserDomainMask,
+                                                          YES) objectAtIndex:0];
+	GoBoltmobiledemoBoltDB * demo = GoBoltmobiledemoNewBoltDB(path);
+	[self addSkipBackupAttributeToItemAtPath:demo.path];
+	//Some DB Logic would go here
+	[demo close];
+}
+
+- (BOOL)addSkipBackupAttributeToItemAtPath:(NSString *) filePathString
+{
+    NSURL* URL= [NSURL fileURLWithPath: filePathString];
+    assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);
+
+    NSError *error = nil;
+    BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]
+                                  forKey: NSURLIsExcludedFromBackupKey error: &error];
+    if(!success){
+        NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error);
+    }
+    return success;
+}
+
+```
+
+## Resources
+
+For more information on getting started with Bolt, check out the following articles:
+
+* [Intro to BoltDB: Painless Performant Persistence](http://npf.io/2014/07/intro-to-boltdb-painless-performant-persistence/) by [Nate Finch](https://github.com/natefinch).
+* [Bolt -- an embedded key/value database for Go](https://www.progville.com/go/bolt-embedded-db-golang/) by Progville
+
+
+## Comparison with other databases
+
+### Postgres, MySQL, & other relational databases
+
+Relational databases structure data into rows and are only accessible through
+the use of SQL. This approach provides flexibility in how you store and query
+your data but also incurs overhead in parsing and planning SQL statements. Bolt
+accesses all data by a byte slice key. This makes Bolt fast to read and write
+data by key but provides no built-in support for joining values together.
+
+Most relational databases (with the exception of SQLite) are standalone servers
+that run separately from your application. This gives your systems
+flexibility to connect multiple application servers to a single database
+server but also adds overhead in serializing and transporting data over the
+network. Bolt runs as a library included in your application so all data access
+has to go through your application's process. This brings data closer to your
+application but limits multi-process access to the data.
+
+
+### LevelDB, RocksDB
+
+LevelDB and its derivatives (RocksDB, HyperLevelDB) are similar to Bolt in that
+they are libraries bundled into the application, however, their underlying
+structure is a log-structured merge-tree (LSM tree). An LSM tree optimizes
+random writes by using a write ahead log and multi-tiered, sorted files called
+SSTables. Bolt uses a B+tree internally and only a single file. Both approaches
+have trade-offs.
+
+If you require a high random write throughput (>10,000 w/sec) or you need to use
+spinning disks then LevelDB could be a good choice. If your application is
+read-heavy or does a lot of range scans then Bolt could be a good choice.
+
+One other important consideration is that LevelDB does not have transactions.
+It supports batch writing of key/values pairs and it supports read snapshots
+but it will not give you the ability to do a compare-and-swap operation safely.
+Bolt supports fully serializable ACID transactions.
+
+
+### LMDB
+
+Bolt was originally a port of LMDB so it is architecturally similar. Both use
+a B+tree, have ACID semantics with fully serializable transactions, and support
+lock-free MVCC using a single writer and multiple readers.
+
+The two projects have somewhat diverged. LMDB heavily focuses on raw performance
+while Bolt has focused on simplicity and ease of use. For example, LMDB allows
+several unsafe actions such as direct writes for the sake of performance. Bolt
+opts to disallow actions which can leave the database in a corrupted state. The
+only exception to this in Bolt is `DB.NoSync`.
+
+There are also a few differences in API. LMDB requires a maximum mmap size when
+opening an `mdb_env` whereas Bolt will handle incremental mmap resizing
+automatically. LMDB overloads the getter and setter functions with multiple
+flags whereas Bolt splits these specialized cases into their own functions.
+
+
+## Caveats & Limitations
+
+It's important to pick the right tool for the job and Bolt is no exception.
+Here are a few things to note when evaluating and using Bolt:
+
+* Bolt is good for read intensive workloads. Sequential write performance is
+  also fast but random writes can be slow. You can use `DB.Batch()` or add a
+  write-ahead log to help mitigate this issue.
+
+* Bolt uses a B+tree internally so there can be a lot of random page access.
+  SSDs provide a significant performance boost over spinning disks.
+
+* Try to avoid long running read transactions. Bolt uses copy-on-write so
+  old pages cannot be reclaimed while an old transaction is using them.
+
+* Byte slices returned from Bolt are only valid during a transaction. Once the
+  transaction has been committed or rolled back then the memory they point to
+  can be reused by a new page or can be unmapped from virtual memory and you'll
+  see an `unexpected fault address` panic when accessing it.
+
+* Bolt uses an exclusive write lock on the database file so it cannot be
+  shared by multiple processes.
+
+* Be careful when using `Bucket.FillPercent`. Setting a high fill percent for
+  buckets that have random inserts will cause your database to have very poor
+  page utilization.
+
+* Use larger buckets in general. Smaller buckets causes poor page utilization
+  once they become larger than the page size (typically 4KB).
+
+* Bulk loading a lot of random writes into a new bucket can be slow as the
+  page will not split until the transaction is committed. Randomly inserting
+  more than 100,000 key/value pairs into a single new bucket in a single
+  transaction is not advised.
+
+* Bolt uses a memory-mapped file so the underlying operating system handles the
+  caching of the data. Typically, the OS will cache as much of the file as it
+  can in memory and will release memory as needed to other processes. This means
+  that Bolt can show very high memory usage when working with large databases.
+  However, this is expected and the OS will release memory as needed. Bolt can
+  handle databases much larger than the available physical RAM, provided its
+  memory-map fits in the process virtual address space. It may be problematic
+  on 32-bits systems.
+
+* The data structures in the Bolt database are memory mapped so the data file
+  will be endian specific. This means that you cannot copy a Bolt file from a
+  little endian machine to a big endian machine and have it work. For most
+  users this is not a concern since most modern CPUs are little endian.
+
+* Because of the way pages are laid out on disk, Bolt cannot truncate data files
+  and return free pages back to the disk. Instead, Bolt maintains a free list
+  of unused pages within its data file. These free pages can be reused by later
+  transactions. This works well for many use cases as databases generally tend
+  to grow. However, it's important to note that deleting large chunks of data
+  will not allow you to reclaim that space on disk.
+
+  For more information on page allocation, [see this comment][page-allocation].
+
+[page-allocation]: https://github.com/boltdb/bolt/issues/308#issuecomment-74811638
+
+
+## Reading the Source
+
+Bolt is a relatively small code base (<5KLOC) for an embedded, serializable,
+transactional key/value database so it can be a good starting point for people
+interested in how databases work.
+
+The best places to start are the main entry points into Bolt:
+
+- `Open()` - Initializes the reference to the database. It's responsible for
+  creating the database if it doesn't exist, obtaining an exclusive lock on the
+  file, reading the meta pages, & memory-mapping the file.
+
+- `DB.Begin()` - Starts a read-only or read-write transaction depending on the
+  value of the `writable` argument. This requires briefly obtaining the "meta"
+  lock to keep track of open transactions. Only one read-write transaction can
+  exist at a time so the "rwlock" is acquired during the life of a read-write
+  transaction.
+
+- `Bucket.Put()` - Writes a key/value pair into a bucket. After validating the
+  arguments, a cursor is used to traverse the B+tree to the page and position
+  where they key & value will be written. Once the position is found, the bucket
+  materializes the underlying page and the page's parent pages into memory as
+  "nodes". These nodes are where mutations occur during read-write transactions.
+  These changes get flushed to disk during commit.
+
+- `Bucket.Get()` - Retrieves a key/value pair from a bucket. This uses a cursor
+  to move to the page & position of a key/value pair. During a read-only
+  transaction, the key and value data is returned as a direct reference to the
+  underlying mmap file so there's no allocation overhead. For read-write
+  transactions, this data may reference the mmap file or one of the in-memory
+  node values.
+
+- `Cursor` - This object is simply for traversing the B+tree of on-disk pages
+  or in-memory nodes. It can seek to a specific key, move to the first or last
+  value, or it can move forward or backward. The cursor handles the movement up
+  and down the B+tree transparently to the end user.
+
+- `Tx.Commit()` - Converts the in-memory dirty nodes and the list of free pages
+  into pages to be written to disk. Writing to disk then occurs in two phases.
+  First, the dirty pages are written to disk and an `fsync()` occurs. Second, a
+  new meta page with an incremented transaction ID is written and another
+  `fsync()` occurs. This two phase write ensures that partially written data
+  pages are ignored in the event of a crash since the meta page pointing to them
+  is never written. Partially written meta pages are invalidated because they
+  are written with a checksum.
+
+If you have additional notes that could be helpful for others, please submit
+them via pull request.
+
+
+## Other Projects Using Bolt
+
+Below is a list of public, open source projects that use Bolt:
+
+* [Algernon](https://github.com/xyproto/algernon) - A HTTP/2 web server with built-in support for Lua. Uses BoltDB as the default database backend.
+* [Bazil](https://bazil.org/) - A file system that lets your data reside where it is most convenient for it to reside.
+* [bolter](https://github.com/hasit/bolter) - Command-line app for viewing BoltDB file in your terminal.
+* [boltcli](https://github.com/spacewander/boltcli) - the redis-cli for boltdb with Lua script support.
+* [BoltHold](https://github.com/timshannon/bolthold) - An embeddable NoSQL store for Go types built on BoltDB
+* [BoltStore](https://github.com/yosssi/boltstore) - Session store using Bolt.
+* [Boltdb Boilerplate](https://github.com/bobintornado/boltdb-boilerplate) - Boilerplate wrapper around bolt aiming to make simple calls one-liners.
+* [BoltDbWeb](https://github.com/evnix/boltdbweb) - A web based GUI for BoltDB files.
+* [bleve](http://www.blevesearch.com/) - A pure Go search engine similar to ElasticSearch that uses Bolt as the default storage backend.
+* [btcwallet](https://github.com/btcsuite/btcwallet) - A bitcoin wallet.
+* [buckets](https://github.com/joyrexus/buckets) - a bolt wrapper streamlining
+  simple tx and key scans.
+* [cayley](https://github.com/google/cayley) - Cayley is an open-source graph database using Bolt as optional backend.
+* [ChainStore](https://github.com/pressly/chainstore) - Simple key-value interface to a variety of storage engines organized as a chain of operations.
+* [Consul](https://github.com/hashicorp/consul) - Consul is service discovery and configuration made easy. Distributed, highly available, and datacenter-aware.
+* [DVID](https://github.com/janelia-flyem/dvid) - Added Bolt as optional storage engine and testing it against Basho-tuned leveldb.
+* [dcrwallet](https://github.com/decred/dcrwallet) - A wallet for the Decred cryptocurrency.
+* [drive](https://github.com/odeke-em/drive) - drive is an unofficial Google Drive command line client for \*NIX operating systems.
+* [event-shuttle](https://github.com/sclasen/event-shuttle) - A Unix system service to collect and reliably deliver messages to Kafka.
+* [Freehold](http://tshannon.bitbucket.org/freehold/) - An open, secure, and lightweight platform for your files and data.
+* [Go Report Card](https://goreportcard.com/) - Go code quality report cards as a (free and open source) service.
+* [GoWebApp](https://github.com/josephspurrier/gowebapp) - A basic MVC web application in Go using BoltDB.
+* [GoShort](https://github.com/pankajkhairnar/goShort) - GoShort is a URL shortener written in Golang and BoltDB for persistent key/value storage and for routing it's using high performent HTTPRouter.
+* [gopherpit](https://github.com/gopherpit/gopherpit) - A web service to manage Go remote import paths with custom domains
+* [Gitchain](https://github.com/gitchain/gitchain) - Decentralized, peer-to-peer Git repositories aka "Git meets Bitcoin".
+* [InfluxDB](https://influxdata.com) - Scalable datastore for metrics, events, and real-time analytics.
+* [ipLocator](https://github.com/AndreasBriese/ipLocator) - A fast ip-geo-location-server using bolt with bloom filters.
+* [ipxed](https://github.com/kelseyhightower/ipxed) - Web interface and api for ipxed.
+* [Ironsmith](https://github.com/timshannon/ironsmith) - A simple, script-driven continuous integration (build - > test -> release) tool, with no external dependencies
+* [Kala](https://github.com/ajvb/kala) - Kala is a modern job scheduler optimized to run on a single node. It is persistent, JSON over HTTP API, ISO 8601 duration notation, and dependent jobs.
+* [Key Value Access Langusge (KVAL)](https://github.com/kval-access-language) - A proposed grammar for key-value datastores offering a bbolt binding.
+* [LedisDB](https://github.com/siddontang/ledisdb) - A high performance NoSQL, using Bolt as optional storage.
+* [lru](https://github.com/crowdriff/lru) - Easy to use Bolt-backed Least-Recently-Used (LRU) read-through cache with chainable remote stores.
+* [mbuckets](https://github.com/abhigupta912/mbuckets) - A Bolt wrapper that allows easy operations on multi level (nested) buckets.
+* [MetricBase](https://github.com/msiebuhr/MetricBase) - Single-binary version of Graphite.
+* [MuLiFS](https://github.com/dankomiocevic/mulifs) - Music Library Filesystem creates a filesystem to organise your music files.
+* [Operation Go: A Routine Mission](http://gocode.io) - An online programming game for Golang using Bolt for user accounts and a leaderboard.
+* [photosite/session](https://godoc.org/bitbucket.org/kardianos/photosite/session) - Sessions for a photo viewing site.
+* [Prometheus Annotation Server](https://github.com/oliver006/prom_annotation_server) - Annotation server for PromDash & Prometheus service monitoring system.
+* [reef-pi](https://github.com/reef-pi/reef-pi) - reef-pi is an award winning, modular, DIY reef tank controller using easy to learn electronics based on a Raspberry Pi.
+* [Request Baskets](https://github.com/darklynx/request-baskets) - A web service to collect arbitrary HTTP requests and inspect them via REST API or simple web UI, similar to [RequestBin](http://requestb.in/) service
+* [Seaweed File System](https://github.com/chrislusf/seaweedfs) - Highly scalable distributed key~file system with O(1) disk read.
+* [stow](https://github.com/djherbis/stow) -  a persistence manager for objects
+  backed by boltdb.
+* [Storm](https://github.com/asdine/storm) - Simple and powerful ORM for BoltDB.
+* [SimpleBolt](https://github.com/xyproto/simplebolt) - A simple way to use BoltDB. Deals mainly with strings.
+* [Skybox Analytics](https://github.com/skybox/skybox) - A standalone funnel analysis tool for web analytics.
+* [Scuttlebutt](https://github.com/benbjohnson/scuttlebutt) - Uses Bolt to store and process all Twitter mentions of GitHub projects.
+* [tentacool](https://github.com/optiflows/tentacool) - REST api server to manage system stuff (IP, DNS, Gateway...) on a linux server.
+* [torrent](https://github.com/anacrolix/torrent) - Full-featured BitTorrent client package and utilities in Go. BoltDB is a storage backend in development.
+* [Wiki](https://github.com/peterhellberg/wiki) - A tiny wiki using Goji, BoltDB and Blackfriday.
+
+If you are using Bolt in a project please send a pull request to add it to the list.
diff --git a/vendor/go.etcd.io/bbolt/bolt_386.go b/vendor/go.etcd.io/bbolt/bolt_386.go
new file mode 100644
index 0000000..4d35ee7
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_386.go
@@ -0,0 +1,10 @@
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_amd64.go b/vendor/go.etcd.io/bbolt/bolt_amd64.go
new file mode 100644
index 0000000..60a52da
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_amd64.go
@@ -0,0 +1,10 @@
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_arm.go b/vendor/go.etcd.io/bbolt/bolt_arm.go
new file mode 100644
index 0000000..105d27d
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_arm.go
@@ -0,0 +1,28 @@
+package bbolt
+
+import "unsafe"
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned bool
+
+func init() {
+	// Simple check to see whether this arch handles unaligned load/stores
+	// correctly.
+
+	// ARM9 and older devices require load/stores to be from/to aligned
+	// addresses. If not, the lower 2 bits are cleared and that address is
+	// read in a jumbled up order.
+
+	// See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15414.html
+
+	raw := [6]byte{0xfe, 0xef, 0x11, 0x22, 0x22, 0x11}
+	val := *(*uint32)(unsafe.Pointer(uintptr(unsafe.Pointer(&raw)) + 2))
+
+	brokenUnaligned = val != 0x11222211
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_arm64.go b/vendor/go.etcd.io/bbolt/bolt_arm64.go
new file mode 100644
index 0000000..f5aa2a5
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_arm64.go
@@ -0,0 +1,12 @@
+// +build arm64
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_linux.go b/vendor/go.etcd.io/bbolt/bolt_linux.go
new file mode 100644
index 0000000..7707bca
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_linux.go
@@ -0,0 +1,10 @@
+package bbolt
+
+import (
+	"syscall"
+)
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return syscall.Fdatasync(int(db.file.Fd()))
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_mips64x.go b/vendor/go.etcd.io/bbolt/bolt_mips64x.go
new file mode 100644
index 0000000..baeb289
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_mips64x.go
@@ -0,0 +1,12 @@
+// +build mips64 mips64le
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x8000000000 // 512GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_mipsx.go b/vendor/go.etcd.io/bbolt/bolt_mipsx.go
new file mode 100644
index 0000000..2d9b1a9
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_mipsx.go
@@ -0,0 +1,12 @@
+// +build mips mipsle
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x40000000 // 1GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_openbsd.go b/vendor/go.etcd.io/bbolt/bolt_openbsd.go
new file mode 100644
index 0000000..d7f5035
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_openbsd.go
@@ -0,0 +1,27 @@
+package bbolt
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const (
+	msAsync      = 1 << iota // perform asynchronous writes
+	msSync                   // perform synchronous writes
+	msInvalidate             // invalidate cached data
+)
+
+func msync(db *DB) error {
+	_, _, errno := syscall.Syscall(syscall.SYS_MSYNC, uintptr(unsafe.Pointer(db.data)), uintptr(db.datasz), msInvalidate)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+func fdatasync(db *DB) error {
+	if db.data != nil {
+		return msync(db)
+	}
+	return db.file.Sync()
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_ppc.go b/vendor/go.etcd.io/bbolt/bolt_ppc.go
new file mode 100644
index 0000000..6980471
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_ppc.go
@@ -0,0 +1,12 @@
+// +build ppc
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0x7FFFFFFF // 2GB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0xFFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_ppc64.go b/vendor/go.etcd.io/bbolt/bolt_ppc64.go
new file mode 100644
index 0000000..3565908
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_ppc64.go
@@ -0,0 +1,12 @@
+// +build ppc64
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_ppc64le.go b/vendor/go.etcd.io/bbolt/bolt_ppc64le.go
new file mode 100644
index 0000000..422c7c6
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_ppc64le.go
@@ -0,0 +1,12 @@
+// +build ppc64le
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_riscv64.go b/vendor/go.etcd.io/bbolt/bolt_riscv64.go
new file mode 100644
index 0000000..07b4b47
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_riscv64.go
@@ -0,0 +1,12 @@
+// +build riscv64
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = true
diff --git a/vendor/go.etcd.io/bbolt/bolt_s390x.go b/vendor/go.etcd.io/bbolt/bolt_s390x.go
new file mode 100644
index 0000000..6d3fcb8
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_s390x.go
@@ -0,0 +1,12 @@
+// +build s390x
+
+package bbolt
+
+// maxMapSize represents the largest mmap size supported by Bolt.
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB
+
+// maxAllocSize is the size used when creating array pointers.
+const maxAllocSize = 0x7FFFFFFF
+
+// Are unaligned load/stores broken on this arch?
+var brokenUnaligned = false
diff --git a/vendor/go.etcd.io/bbolt/bolt_unix.go b/vendor/go.etcd.io/bbolt/bolt_unix.go
new file mode 100644
index 0000000..5f2bb51
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_unix.go
@@ -0,0 +1,93 @@
+// +build !windows,!plan9,!solaris
+
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	flag := syscall.LOCK_NB
+	if exclusive {
+		flag |= syscall.LOCK_EX
+	} else {
+		flag |= syscall.LOCK_SH
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		err := syscall.Flock(int(fd), flag)
+		if err == nil {
+			return nil
+		} else if err != syscall.EWOULDBLOCK {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	return syscall.Flock(int(db.file.Fd()), syscall.LOCK_UN)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := syscall.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	err = madvise(b, syscall.MADV_RANDOM)
+	if err != nil && err != syscall.ENOSYS {
+		// Ignore not implemented error in kernel because it still works.
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := syscall.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
+
+// NOTE: This function is copied from stdlib because it is not available on darwin.
+func madvise(b []byte, advice int) (err error) {
+	_, _, e1 := syscall.Syscall(syscall.SYS_MADVISE, uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(advice))
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_unix_solaris.go b/vendor/go.etcd.io/bbolt/bolt_unix_solaris.go
new file mode 100644
index 0000000..babad65
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_unix_solaris.go
@@ -0,0 +1,88 @@
+package bbolt
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	fd := db.file.Fd()
+	var lockType int16
+	if exclusive {
+		lockType = syscall.F_WRLCK
+	} else {
+		lockType = syscall.F_RDLCK
+	}
+	for {
+		// Attempt to obtain an exclusive lock.
+		lock := syscall.Flock_t{Type: lockType}
+		err := syscall.FcntlFlock(fd, syscall.F_SETLK, &lock)
+		if err == nil {
+			return nil
+		} else if err != syscall.EAGAIN {
+			return err
+		}
+
+		// If we timed out then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	return syscall.FcntlFlock(uintptr(db.file.Fd()), syscall.F_SETLK, &lock)
+}
+
+// mmap memory maps a DB's data file.
+func mmap(db *DB, sz int) error {
+	// Map the data file to memory.
+	b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED|db.MmapFlags)
+	if err != nil {
+		return err
+	}
+
+	// Advise the kernel that the mmap is accessed randomly.
+	if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
+		return fmt.Errorf("madvise: %s", err)
+	}
+
+	// Save the original byte slice and convert to a byte array pointer.
+	db.dataref = b
+	db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
+	db.datasz = sz
+	return nil
+}
+
+// munmap unmaps a DB's data file from memory.
+func munmap(db *DB) error {
+	// Ignore the unmap if we have no mapped data.
+	if db.dataref == nil {
+		return nil
+	}
+
+	// Unmap using the original byte slice.
+	err := unix.Munmap(db.dataref)
+	db.dataref = nil
+	db.data = nil
+	db.datasz = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/bbolt/bolt_windows.go b/vendor/go.etcd.io/bbolt/bolt_windows.go
new file mode 100644
index 0000000..fca178b
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bolt_windows.go
@@ -0,0 +1,141 @@
+package bbolt
+
+import (
+	"fmt"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// LockFileEx code derived from golang build filemutex_windows.go @ v1.5.1
+var (
+	modkernel32      = syscall.NewLazyDLL("kernel32.dll")
+	procLockFileEx   = modkernel32.NewProc("LockFileEx")
+	procUnlockFileEx = modkernel32.NewProc("UnlockFileEx")
+)
+
+const (
+	// see https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx
+	flagLockExclusive       = 2
+	flagLockFailImmediately = 1
+
+	// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx
+	errLockViolation syscall.Errno = 0x21
+)
+
+func lockFileEx(h syscall.Handle, flags, reserved, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
+	r, _, err := procLockFileEx.Call(uintptr(h), uintptr(flags), uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)))
+	if r == 0 {
+		return err
+	}
+	return nil
+}
+
+func unlockFileEx(h syscall.Handle, reserved, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
+	r, _, err := procUnlockFileEx.Call(uintptr(h), uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)), 0)
+	if r == 0 {
+		return err
+	}
+	return nil
+}
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}
+
+// flock acquires an advisory lock on a file descriptor.
+func flock(db *DB, exclusive bool, timeout time.Duration) error {
+	var t time.Time
+	if timeout != 0 {
+		t = time.Now()
+	}
+	var flag uint32 = flagLockFailImmediately
+	if exclusive {
+		flag |= flagLockExclusive
+	}
+	for {
+		// Fix for https://github.com/etcd-io/bbolt/issues/121. Use byte-range
+		// -1..0 as the lock on the database file.
+		var m1 uint32 = (1 << 32) - 1 // -1 in a uint32
+		err := lockFileEx(syscall.Handle(db.file.Fd()), flag, 0, 1, 0, &syscall.Overlapped{
+			Offset:     m1,
+			OffsetHigh: m1,
+		})
+
+		if err == nil {
+			return nil
+		} else if err != errLockViolation {
+			return err
+		}
+
+		// If we timed oumercit then return an error.
+		if timeout != 0 && time.Since(t) > timeout-flockRetryTimeout {
+			return ErrTimeout
+		}
+
+		// Wait for a bit and try again.
+		time.Sleep(flockRetryTimeout)
+	}
+}
+
+// funlock releases an advisory lock on a file descriptor.
+func funlock(db *DB) error {
+	var m1 uint32 = (1 << 32) - 1 // -1 in a uint32
+	err := unlockFileEx(syscall.Handle(db.file.Fd()), 0, 1, 0, &syscall.Overlapped{
+		Offset:     m1,
+		OffsetHigh: m1,
+	})
+	return err
+}
+
+// mmap memory maps a DB's data file.
+// Based on: https://github.com/edsrzf/mmap-go
+func mmap(db *DB, sz int) error {
+	if !db.readOnly {
+		// Truncate the database to the size of the mmap.
+		if err := db.file.Truncate(int64(sz)); err != nil {
+			return fmt.Errorf("truncate: %s", err)
+		}
+	}
+
+	// Open a file mapping handle.
+	sizelo := uint32(sz >> 32)
+	sizehi := uint32(sz) & 0xffffffff
+	h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil)
+	if h == 0 {
+		return os.NewSyscallError("CreateFileMapping", errno)
+	}
+
+	// Create the memory map.
+	addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
+	if addr == 0 {
+		return os.NewSyscallError("MapViewOfFile", errno)
+	}
+
+	// Close mapping handle.
+	if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
+		return os.NewSyscallError("CloseHandle", err)
+	}
+
+	// Convert to a byte array.
+	db.data = ((*[maxMapSize]byte)(unsafe.Pointer(addr)))
+	db.datasz = sz
+
+	return nil
+}
+
+// munmap unmaps a pointer from a file.
+// Based on: https://github.com/edsrzf/mmap-go
+func munmap(db *DB) error {
+	if db.data == nil {
+		return nil
+	}
+
+	addr := (uintptr)(unsafe.Pointer(&db.data[0]))
+	if err := syscall.UnmapViewOfFile(addr); err != nil {
+		return os.NewSyscallError("UnmapViewOfFile", err)
+	}
+	return nil
+}
diff --git a/vendor/go.etcd.io/bbolt/boltsync_unix.go b/vendor/go.etcd.io/bbolt/boltsync_unix.go
new file mode 100644
index 0000000..9587afe
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/boltsync_unix.go
@@ -0,0 +1,8 @@
+// +build !windows,!plan9,!linux,!openbsd
+
+package bbolt
+
+// fdatasync flushes written data to a file descriptor.
+func fdatasync(db *DB) error {
+	return db.file.Sync()
+}
diff --git a/vendor/go.etcd.io/bbolt/bucket.go b/vendor/go.etcd.io/bbolt/bucket.go
new file mode 100644
index 0000000..84bfd4d
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/bucket.go
@@ -0,0 +1,775 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"unsafe"
+)
+
+const (
+	// MaxKeySize is the maximum length of a key, in bytes.
+	MaxKeySize = 32768
+
+	// MaxValueSize is the maximum length of a value, in bytes.
+	MaxValueSize = (1 << 31) - 2
+)
+
+const bucketHeaderSize = int(unsafe.Sizeof(bucket{}))
+
+const (
+	minFillPercent = 0.1
+	maxFillPercent = 1.0
+)
+
+// DefaultFillPercent is the percentage that split pages are filled.
+// This value can be changed by setting Bucket.FillPercent.
+const DefaultFillPercent = 0.5
+
+// Bucket represents a collection of key/value pairs inside the database.
+type Bucket struct {
+	*bucket
+	tx       *Tx                // the associated transaction
+	buckets  map[string]*Bucket // subbucket cache
+	page     *page              // inline page reference
+	rootNode *node              // materialized node for the root page.
+	nodes    map[pgid]*node     // node cache
+
+	// Sets the threshold for filling nodes when they split. By default,
+	// the bucket will fill to 50% but it can be useful to increase this
+	// amount if you know that your write workloads are mostly append-only.
+	//
+	// This is non-persisted across transactions so it must be set in every Tx.
+	FillPercent float64
+}
+
+// bucket represents the on-file representation of a bucket.
+// This is stored as the "value" of a bucket key. If the bucket is small enough,
+// then its root page can be stored inline in the "value", after the bucket
+// header. In the case of inline buckets, the "root" will be 0.
+type bucket struct {
+	root     pgid   // page id of the bucket's root-level page
+	sequence uint64 // monotonically incrementing, used by NextSequence()
+}
+
+// newBucket returns a new bucket associated with a transaction.
+func newBucket(tx *Tx) Bucket {
+	var b = Bucket{tx: tx, FillPercent: DefaultFillPercent}
+	if tx.writable {
+		b.buckets = make(map[string]*Bucket)
+		b.nodes = make(map[pgid]*node)
+	}
+	return b
+}
+
+// Tx returns the tx of the bucket.
+func (b *Bucket) Tx() *Tx {
+	return b.tx
+}
+
+// Root returns the root of the bucket.
+func (b *Bucket) Root() pgid {
+	return b.root
+}
+
+// Writable returns whether the bucket is writable.
+func (b *Bucket) Writable() bool {
+	return b.tx.writable
+}
+
+// Cursor creates a cursor associated with the bucket.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (b *Bucket) Cursor() *Cursor {
+	// Update transaction statistics.
+	b.tx.stats.CursorCount++
+
+	// Allocate and return a cursor.
+	return &Cursor{
+		bucket: b,
+		stack:  make([]elemRef, 0),
+	}
+}
+
+// Bucket retrieves a nested bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) Bucket(name []byte) *Bucket {
+	if b.buckets != nil {
+		if child := b.buckets[string(name)]; child != nil {
+			return child
+		}
+	}
+
+	// Move cursor to key.
+	c := b.Cursor()
+	k, v, flags := c.seek(name)
+
+	// Return nil if the key doesn't exist or it is not a bucket.
+	if !bytes.Equal(name, k) || (flags&bucketLeafFlag) == 0 {
+		return nil
+	}
+
+	// Otherwise create a bucket and cache it.
+	var child = b.openBucket(v)
+	if b.buckets != nil {
+		b.buckets[string(name)] = child
+	}
+
+	return child
+}
+
+// Helper method that re-interprets a sub-bucket value
+// from a parent into a Bucket
+func (b *Bucket) openBucket(value []byte) *Bucket {
+	var child = newBucket(b.tx)
+
+	// If unaligned load/stores are broken on this arch and value is
+	// unaligned simply clone to an aligned byte array.
+	unaligned := brokenUnaligned && uintptr(unsafe.Pointer(&value[0]))&3 != 0
+
+	if unaligned {
+		value = cloneBytes(value)
+	}
+
+	// If this is a writable transaction then we need to copy the bucket entry.
+	// Read-only transactions can point directly at the mmap entry.
+	if b.tx.writable && !unaligned {
+		child.bucket = &bucket{}
+		*child.bucket = *(*bucket)(unsafe.Pointer(&value[0]))
+	} else {
+		child.bucket = (*bucket)(unsafe.Pointer(&value[0]))
+	}
+
+	// Save a reference to the inline page if the bucket is inline.
+	if child.root == 0 {
+		child.page = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
+	}
+
+	return &child
+}
+
+// CreateBucket creates a new bucket at the given key and returns the new bucket.
+// Returns an error if the key already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucket(key []byte) (*Bucket, error) {
+	if b.tx.db == nil {
+		return nil, ErrTxClosed
+	} else if !b.tx.writable {
+		return nil, ErrTxNotWritable
+	} else if len(key) == 0 {
+		return nil, ErrBucketNameRequired
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key.
+	if bytes.Equal(key, k) {
+		if (flags & bucketLeafFlag) != 0 {
+			return nil, ErrBucketExists
+		}
+		return nil, ErrIncompatibleValue
+	}
+
+	// Create empty, inline bucket.
+	var bucket = Bucket{
+		bucket:      &bucket{},
+		rootNode:    &node{isLeaf: true},
+		FillPercent: DefaultFillPercent,
+	}
+	var value = bucket.write()
+
+	// Insert into node.
+	key = cloneBytes(key)
+	c.node().put(key, key, value, 0, bucketLeafFlag)
+
+	// Since subbuckets are not allowed on inline buckets, we need to
+	// dereference the inline page, if it exists. This will cause the bucket
+	// to be treated as a regular, non-inline bucket for the rest of the tx.
+	b.page = nil
+
+	return b.Bucket(key), nil
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist and returns a reference to it.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (b *Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error) {
+	child, err := b.CreateBucket(key)
+	if err == ErrBucketExists {
+		return b.Bucket(key), nil
+	} else if err != nil {
+		return nil, err
+	}
+	return child, nil
+}
+
+// DeleteBucket deletes a bucket at the given key.
+// Returns an error if the bucket does not exists, or if the key represents a non-bucket value.
+func (b *Bucket) DeleteBucket(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if bucket doesn't exist or is not a bucket.
+	if !bytes.Equal(key, k) {
+		return ErrBucketNotFound
+	} else if (flags & bucketLeafFlag) == 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Recursively delete all child buckets.
+	child := b.Bucket(key)
+	err := child.ForEach(func(k, v []byte) error {
+		if v == nil {
+			if err := child.DeleteBucket(k); err != nil {
+				return fmt.Errorf("delete bucket: %s", err)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// Remove cached copy.
+	delete(b.buckets, string(key))
+
+	// Release all bucket pages to freelist.
+	child.nodes = nil
+	child.rootNode = nil
+	child.free()
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
+}
+
+// Get retrieves the value for a key in the bucket.
+// Returns a nil value if the key does not exist or if the key is a nested bucket.
+// The returned value is only valid for the life of the transaction.
+func (b *Bucket) Get(key []byte) []byte {
+	k, v, flags := b.Cursor().seek(key)
+
+	// Return nil if this is a bucket.
+	if (flags & bucketLeafFlag) != 0 {
+		return nil
+	}
+
+	// If our target node isn't the same key as what's passed in then return nil.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
+	return v
+}
+
+// Put sets the value for a key in the bucket.
+// If the key exist then its previous value will be overwritten.
+// Supplied value must remain valid for the life of the transaction.
+// Returns an error if the bucket was created from a read-only transaction, if the key is blank, if the key is too large, or if the value is too large.
+func (b *Bucket) Put(key []byte, value []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	} else if len(key) == 0 {
+		return ErrKeyRequired
+	} else if len(key) > MaxKeySize {
+		return ErrKeyTooLarge
+	} else if int64(len(value)) > MaxValueSize {
+		return ErrValueTooLarge
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return an error if there is an existing key with a bucket value.
+	if bytes.Equal(key, k) && (flags&bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Insert into node.
+	key = cloneBytes(key)
+	c.node().put(key, key, value, 0, 0)
+
+	return nil
+}
+
+// Delete removes a key from the bucket.
+// If the key does not exist then nothing is done and a nil error is returned.
+// Returns an error if the bucket was created from a read-only transaction.
+func (b *Bucket) Delete(key []byte) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Move cursor to correct position.
+	c := b.Cursor()
+	k, _, flags := c.seek(key)
+
+	// Return nil if the key doesn't exist.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
+
+	// Return an error if there is already existing bucket value.
+	if (flags & bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+
+	// Delete the node if we have a matching key.
+	c.node().del(key)
+
+	return nil
+}
+
+// Sequence returns the current integer for the bucket without incrementing it.
+func (b *Bucket) Sequence() uint64 { return b.bucket.sequence }
+
+// SetSequence updates the sequence number for the bucket.
+func (b *Bucket) SetSequence(v uint64) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	} else if !b.Writable() {
+		return ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.root, nil)
+	}
+
+	// Increment and return the sequence.
+	b.bucket.sequence = v
+	return nil
+}
+
+// NextSequence returns an autoincrementing integer for the bucket.
+func (b *Bucket) NextSequence() (uint64, error) {
+	if b.tx.db == nil {
+		return 0, ErrTxClosed
+	} else if !b.Writable() {
+		return 0, ErrTxNotWritable
+	}
+
+	// Materialize the root node if it hasn't been already so that the
+	// bucket will be saved during commit.
+	if b.rootNode == nil {
+		_ = b.node(b.root, nil)
+	}
+
+	// Increment and return the sequence.
+	b.bucket.sequence++
+	return b.bucket.sequence, nil
+}
+
+// ForEach executes a function for each key/value pair in a bucket.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller. The provided function must not modify
+// the bucket; this will result in undefined behavior.
+func (b *Bucket) ForEach(fn func(k, v []byte) error) error {
+	if b.tx.db == nil {
+		return ErrTxClosed
+	}
+	c := b.Cursor()
+	for k, v := c.First(); k != nil; k, v = c.Next() {
+		if err := fn(k, v); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Stat returns stats on a bucket.
+func (b *Bucket) Stats() BucketStats {
+	var s, subStats BucketStats
+	pageSize := b.tx.db.pageSize
+	s.BucketN += 1
+	if b.root == 0 {
+		s.InlineBucketN += 1
+	}
+	b.forEachPage(func(p *page, depth int) {
+		if (p.flags & leafPageFlag) != 0 {
+			s.KeyN += int(p.count)
+
+			// used totals the used bytes for the page
+			used := pageHeaderSize
+
+			if p.count != 0 {
+				// If page has any elements, add all element headers.
+				used += leafPageElementSize * int(p.count-1)
+
+				// Add all element key, value sizes.
+				// The computation takes advantage of the fact that the position
+				// of the last element's key/value equals to the total of the sizes
+				// of all previous elements' keys and values.
+				// It also includes the last element's header.
+				lastElement := p.leafPageElement(p.count - 1)
+				used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
+			}
+
+			if b.root == 0 {
+				// For inlined bucket just update the inline stats
+				s.InlineBucketInuse += used
+			} else {
+				// For non-inlined bucket update all the leaf stats
+				s.LeafPageN++
+				s.LeafInuse += used
+				s.LeafOverflowN += int(p.overflow)
+
+				// Collect stats from sub-buckets.
+				// Do that by iterating over all element headers
+				// looking for the ones with the bucketLeafFlag.
+				for i := uint16(0); i < p.count; i++ {
+					e := p.leafPageElement(i)
+					if (e.flags & bucketLeafFlag) != 0 {
+						// For any bucket element, open the element value
+						// and recursively call Stats on the contained bucket.
+						subStats.Add(b.openBucket(e.value()).Stats())
+					}
+				}
+			}
+		} else if (p.flags & branchPageFlag) != 0 {
+			s.BranchPageN++
+			lastElement := p.branchPageElement(p.count - 1)
+
+			// used totals the used bytes for the page
+			// Add header and all element headers.
+			used := pageHeaderSize + (branchPageElementSize * int(p.count-1))
+
+			// Add size of all keys and values.
+			// Again, use the fact that last element's position equals to
+			// the total of key, value sizes of all previous elements.
+			used += int(lastElement.pos + lastElement.ksize)
+			s.BranchInuse += used
+			s.BranchOverflowN += int(p.overflow)
+		}
+
+		// Keep track of maximum page depth.
+		if depth+1 > s.Depth {
+			s.Depth = (depth + 1)
+		}
+	})
+
+	// Alloc stats can be computed from page counts and pageSize.
+	s.BranchAlloc = (s.BranchPageN + s.BranchOverflowN) * pageSize
+	s.LeafAlloc = (s.LeafPageN + s.LeafOverflowN) * pageSize
+
+	// Add the max depth of sub-buckets to get total nested depth.
+	s.Depth += subStats.Depth
+	// Add the stats for all sub-buckets
+	s.Add(subStats)
+	return s
+}
+
+// forEachPage iterates over every page in a bucket, including inline pages.
+func (b *Bucket) forEachPage(fn func(*page, int)) {
+	// If we have an inline page then just use that.
+	if b.page != nil {
+		fn(b.page, 0)
+		return
+	}
+
+	// Otherwise traverse the page hierarchy.
+	b.tx.forEachPage(b.root, 0, fn)
+}
+
+// forEachPageNode iterates over every page (or node) in a bucket.
+// This also includes inline pages.
+func (b *Bucket) forEachPageNode(fn func(*page, *node, int)) {
+	// If we have an inline page or root node then just use that.
+	if b.page != nil {
+		fn(b.page, nil, 0)
+		return
+	}
+	b._forEachPageNode(b.root, 0, fn)
+}
+
+func (b *Bucket) _forEachPageNode(pgid pgid, depth int, fn func(*page, *node, int)) {
+	var p, n = b.pageNode(pgid)
+
+	// Execute function.
+	fn(p, n, depth)
+
+	// Recursively loop over children.
+	if p != nil {
+		if (p.flags & branchPageFlag) != 0 {
+			for i := 0; i < int(p.count); i++ {
+				elem := p.branchPageElement(uint16(i))
+				b._forEachPageNode(elem.pgid, depth+1, fn)
+			}
+		}
+	} else {
+		if !n.isLeaf {
+			for _, inode := range n.inodes {
+				b._forEachPageNode(inode.pgid, depth+1, fn)
+			}
+		}
+	}
+}
+
+// spill writes all the nodes for this bucket to dirty pages.
+func (b *Bucket) spill() error {
+	// Spill all child buckets first.
+	for name, child := range b.buckets {
+		// If the child bucket is small enough and it has no child buckets then
+		// write it inline into the parent bucket's page. Otherwise spill it
+		// like a normal bucket and make the parent value a pointer to the page.
+		var value []byte
+		if child.inlineable() {
+			child.free()
+			value = child.write()
+		} else {
+			if err := child.spill(); err != nil {
+				return err
+			}
+
+			// Update the child bucket header in this bucket.
+			value = make([]byte, unsafe.Sizeof(bucket{}))
+			var bucket = (*bucket)(unsafe.Pointer(&value[0]))
+			*bucket = *child.bucket
+		}
+
+		// Skip writing the bucket if there are no materialized nodes.
+		if child.rootNode == nil {
+			continue
+		}
+
+		// Update parent node.
+		var c = b.Cursor()
+		k, _, flags := c.seek([]byte(name))
+		if !bytes.Equal([]byte(name), k) {
+			panic(fmt.Sprintf("misplaced bucket header: %x -> %x", []byte(name), k))
+		}
+		if flags&bucketLeafFlag == 0 {
+			panic(fmt.Sprintf("unexpected bucket header flag: %x", flags))
+		}
+		c.node().put([]byte(name), []byte(name), value, 0, bucketLeafFlag)
+	}
+
+	// Ignore if there's not a materialized root node.
+	if b.rootNode == nil {
+		return nil
+	}
+
+	// Spill nodes.
+	if err := b.rootNode.spill(); err != nil {
+		return err
+	}
+	b.rootNode = b.rootNode.root()
+
+	// Update the root node for this bucket.
+	if b.rootNode.pgid >= b.tx.meta.pgid {
+		panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", b.rootNode.pgid, b.tx.meta.pgid))
+	}
+	b.root = b.rootNode.pgid
+
+	return nil
+}
+
+// inlineable returns true if a bucket is small enough to be written inline
+// and if it contains no subbuckets. Otherwise returns false.
+func (b *Bucket) inlineable() bool {
+	var n = b.rootNode
+
+	// Bucket must only contain a single leaf node.
+	if n == nil || !n.isLeaf {
+		return false
+	}
+
+	// Bucket is not inlineable if it contains subbuckets or if it goes beyond
+	// our threshold for inline bucket size.
+	var size = pageHeaderSize
+	for _, inode := range n.inodes {
+		size += leafPageElementSize + len(inode.key) + len(inode.value)
+
+		if inode.flags&bucketLeafFlag != 0 {
+			return false
+		} else if size > b.maxInlineBucketSize() {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Returns the maximum total size of a bucket to make it a candidate for inlining.
+func (b *Bucket) maxInlineBucketSize() int {
+	return b.tx.db.pageSize / 4
+}
+
+// write allocates and writes a bucket to a byte slice.
+func (b *Bucket) write() []byte {
+	// Allocate the appropriate size.
+	var n = b.rootNode
+	var value = make([]byte, bucketHeaderSize+n.size())
+
+	// Write a bucket header.
+	var bucket = (*bucket)(unsafe.Pointer(&value[0]))
+	*bucket = *b.bucket
+
+	// Convert byte slice to a fake page and write the root node.
+	var p = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
+	n.write(p)
+
+	return value
+}
+
+// rebalance attempts to balance all nodes.
+func (b *Bucket) rebalance() {
+	for _, n := range b.nodes {
+		n.rebalance()
+	}
+	for _, child := range b.buckets {
+		child.rebalance()
+	}
+}
+
+// node creates a node from a page and associates it with a given parent.
+func (b *Bucket) node(pgid pgid, parent *node) *node {
+	_assert(b.nodes != nil, "nodes map expected")
+
+	// Retrieve node if it's already been created.
+	if n := b.nodes[pgid]; n != nil {
+		return n
+	}
+
+	// Otherwise create a node and cache it.
+	n := &node{bucket: b, parent: parent}
+	if parent == nil {
+		b.rootNode = n
+	} else {
+		parent.children = append(parent.children, n)
+	}
+
+	// Use the inline page if this is an inline bucket.
+	var p = b.page
+	if p == nil {
+		p = b.tx.page(pgid)
+	}
+
+	// Read the page into the node and cache it.
+	n.read(p)
+	b.nodes[pgid] = n
+
+	// Update statistics.
+	b.tx.stats.NodeCount++
+
+	return n
+}
+
+// free recursively frees all pages in the bucket.
+func (b *Bucket) free() {
+	if b.root == 0 {
+		return
+	}
+
+	var tx = b.tx
+	b.forEachPageNode(func(p *page, n *node, _ int) {
+		if p != nil {
+			tx.db.freelist.free(tx.meta.txid, p)
+		} else {
+			n.free()
+		}
+	})
+	b.root = 0
+}
+
+// dereference removes all references to the old mmap.
+func (b *Bucket) dereference() {
+	if b.rootNode != nil {
+		b.rootNode.root().dereference()
+	}
+
+	for _, child := range b.buckets {
+		child.dereference()
+	}
+}
+
+// pageNode returns the in-memory node, if it exists.
+// Otherwise returns the underlying page.
+func (b *Bucket) pageNode(id pgid) (*page, *node) {
+	// Inline buckets have a fake page embedded in their value so treat them
+	// differently. We'll return the rootNode (if available) or the fake page.
+	if b.root == 0 {
+		if id != 0 {
+			panic(fmt.Sprintf("inline bucket non-zero page access(2): %d != 0", id))
+		}
+		if b.rootNode != nil {
+			return nil, b.rootNode
+		}
+		return b.page, nil
+	}
+
+	// Check the node cache for non-inline buckets.
+	if b.nodes != nil {
+		if n := b.nodes[id]; n != nil {
+			return nil, n
+		}
+	}
+
+	// Finally lookup the page from the transaction if no node is materialized.
+	return b.tx.page(id), nil
+}
+
+// BucketStats records statistics about resources used by a bucket.
+type BucketStats struct {
+	// Page count statistics.
+	BranchPageN     int // number of logical branch pages
+	BranchOverflowN int // number of physical branch overflow pages
+	LeafPageN       int // number of logical leaf pages
+	LeafOverflowN   int // number of physical leaf overflow pages
+
+	// Tree statistics.
+	KeyN  int // number of keys/value pairs
+	Depth int // number of levels in B+tree
+
+	// Page size utilization.
+	BranchAlloc int // bytes allocated for physical branch pages
+	BranchInuse int // bytes actually used for branch data
+	LeafAlloc   int // bytes allocated for physical leaf pages
+	LeafInuse   int // bytes actually used for leaf data
+
+	// Bucket statistics
+	BucketN           int // total number of buckets including the top bucket
+	InlineBucketN     int // total number on inlined buckets
+	InlineBucketInuse int // bytes used for inlined buckets (also accounted for in LeafInuse)
+}
+
+func (s *BucketStats) Add(other BucketStats) {
+	s.BranchPageN += other.BranchPageN
+	s.BranchOverflowN += other.BranchOverflowN
+	s.LeafPageN += other.LeafPageN
+	s.LeafOverflowN += other.LeafOverflowN
+	s.KeyN += other.KeyN
+	if s.Depth < other.Depth {
+		s.Depth = other.Depth
+	}
+	s.BranchAlloc += other.BranchAlloc
+	s.BranchInuse += other.BranchInuse
+	s.LeafAlloc += other.LeafAlloc
+	s.LeafInuse += other.LeafInuse
+
+	s.BucketN += other.BucketN
+	s.InlineBucketN += other.InlineBucketN
+	s.InlineBucketInuse += other.InlineBucketInuse
+}
+
+// cloneBytes returns a copy of a given slice.
+func cloneBytes(v []byte) []byte {
+	var clone = make([]byte, len(v))
+	copy(clone, v)
+	return clone
+}
diff --git a/vendor/go.etcd.io/bbolt/cursor.go b/vendor/go.etcd.io/bbolt/cursor.go
new file mode 100644
index 0000000..3000ace
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/cursor.go
@@ -0,0 +1,396 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+)
+
+// Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order.
+// Cursors see nested buckets with value == nil.
+// Cursors can be obtained from a transaction and are valid as long as the transaction is open.
+//
+// Keys and values returned from the cursor are only valid for the life of the transaction.
+//
+// Changing data while traversing with a cursor may cause it to be invalidated
+// and return unexpected keys and/or values. You must reposition your cursor
+// after mutating data.
+type Cursor struct {
+	bucket *Bucket
+	stack  []elemRef
+}
+
+// Bucket returns the bucket that this cursor was created from.
+func (c *Cursor) Bucket() *Bucket {
+	return c.bucket
+}
+
+// First moves the cursor to the first item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) First() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.root)
+	c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	c.first()
+
+	// If we land on an empty page then move to the next value.
+	// https://github.com/boltdb/bolt/issues/450
+	if c.stack[len(c.stack)-1].count() == 0 {
+		c.next()
+	}
+
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+
+}
+
+// Last moves the cursor to the last item in the bucket and returns its key and value.
+// If the bucket is empty then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Last() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	c.stack = c.stack[:0]
+	p, n := c.bucket.pageNode(c.bucket.root)
+	ref := elemRef{page: p, node: n}
+	ref.index = ref.count() - 1
+	c.stack = append(c.stack, ref)
+	c.last()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Next moves the cursor to the next item in the bucket and returns its key and value.
+// If the cursor is at the end of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Next() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+	k, v, flags := c.next()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Prev moves the cursor to the previous item in the bucket and returns its key and value.
+// If the cursor is at the beginning of the bucket then a nil key and value are returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Prev() (key []byte, value []byte) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+
+	// Attempt to move back one element until we're successful.
+	// Move up the stack as we hit the beginning of each page in our stack.
+	for i := len(c.stack) - 1; i >= 0; i-- {
+		elem := &c.stack[i]
+		if elem.index > 0 {
+			elem.index--
+			break
+		}
+		c.stack = c.stack[:i]
+	}
+
+	// If we've hit the end then return nil.
+	if len(c.stack) == 0 {
+		return nil, nil
+	}
+
+	// Move down the stack to find the last element of the last leaf under this branch.
+	c.last()
+	k, v, flags := c.keyValue()
+	if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used. If no keys
+// follow, a nil key is returned.
+// The returned key and value are only valid for the life of the transaction.
+func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
+	k, v, flags := c.seek(seek)
+
+	// If we ended up after the last element of a page then move to the next one.
+	if ref := &c.stack[len(c.stack)-1]; ref.index >= ref.count() {
+		k, v, flags = c.next()
+	}
+
+	if k == nil {
+		return nil, nil
+	} else if (flags & uint32(bucketLeafFlag)) != 0 {
+		return k, nil
+	}
+	return k, v
+}
+
+// Delete removes the current key/value under the cursor from the bucket.
+// Delete fails if current key/value is a bucket or if the transaction is not writable.
+func (c *Cursor) Delete() error {
+	if c.bucket.tx.db == nil {
+		return ErrTxClosed
+	} else if !c.bucket.Writable() {
+		return ErrTxNotWritable
+	}
+
+	key, _, flags := c.keyValue()
+	// Return an error if current value is a bucket.
+	if (flags & bucketLeafFlag) != 0 {
+		return ErrIncompatibleValue
+	}
+	c.node().del(key)
+
+	return nil
+}
+
+// seek moves the cursor to a given key and returns it.
+// If the key does not exist then the next key is used.
+func (c *Cursor) seek(seek []byte) (key []byte, value []byte, flags uint32) {
+	_assert(c.bucket.tx.db != nil, "tx closed")
+
+	// Start from root page/node and traverse to correct page.
+	c.stack = c.stack[:0]
+	c.search(seek, c.bucket.root)
+
+	// If this is a bucket then return a nil value.
+	return c.keyValue()
+}
+
+// first moves the cursor to the first leaf element under the last page in the stack.
+func (c *Cursor) first() {
+	for {
+		// Exit when we hit a leaf page.
+		var ref = &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the first element to the stack.
+		var pgid pgid
+		if ref.node != nil {
+			pgid = ref.node.inodes[ref.index].pgid
+		} else {
+			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
+		}
+		p, n := c.bucket.pageNode(pgid)
+		c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
+	}
+}
+
+// last moves the cursor to the last leaf element under the last page in the stack.
+func (c *Cursor) last() {
+	for {
+		// Exit when we hit a leaf page.
+		ref := &c.stack[len(c.stack)-1]
+		if ref.isLeaf() {
+			break
+		}
+
+		// Keep adding pages pointing to the last element in the stack.
+		var pgid pgid
+		if ref.node != nil {
+			pgid = ref.node.inodes[ref.index].pgid
+		} else {
+			pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
+		}
+		p, n := c.bucket.pageNode(pgid)
+
+		var nextRef = elemRef{page: p, node: n}
+		nextRef.index = nextRef.count() - 1
+		c.stack = append(c.stack, nextRef)
+	}
+}
+
+// next moves to the next leaf element and returns the key and value.
+// If the cursor is at the last leaf element then it stays there and returns nil.
+func (c *Cursor) next() (key []byte, value []byte, flags uint32) {
+	for {
+		// Attempt to move over one element until we're successful.
+		// Move up the stack as we hit the end of each page in our stack.
+		var i int
+		for i = len(c.stack) - 1; i >= 0; i-- {
+			elem := &c.stack[i]
+			if elem.index < elem.count()-1 {
+				elem.index++
+				break
+			}
+		}
+
+		// If we've hit the root page then stop and return. This will leave the
+		// cursor on the last element of the last page.
+		if i == -1 {
+			return nil, nil, 0
+		}
+
+		// Otherwise start from where we left off in the stack and find the
+		// first element of the first leaf page.
+		c.stack = c.stack[:i+1]
+		c.first()
+
+		// If this is an empty page then restart and move back up the stack.
+		// https://github.com/boltdb/bolt/issues/450
+		if c.stack[len(c.stack)-1].count() == 0 {
+			continue
+		}
+
+		return c.keyValue()
+	}
+}
+
+// search recursively performs a binary search against a given page/node until it finds a given key.
+func (c *Cursor) search(key []byte, pgid pgid) {
+	p, n := c.bucket.pageNode(pgid)
+	if p != nil && (p.flags&(branchPageFlag|leafPageFlag)) == 0 {
+		panic(fmt.Sprintf("invalid page type: %d: %x", p.id, p.flags))
+	}
+	e := elemRef{page: p, node: n}
+	c.stack = append(c.stack, e)
+
+	// If we're on a leaf page/node then find the specific node.
+	if e.isLeaf() {
+		c.nsearch(key)
+		return
+	}
+
+	if n != nil {
+		c.searchNode(key, n)
+		return
+	}
+	c.searchPage(key, p)
+}
+
+func (c *Cursor) searchNode(key []byte, n *node) {
+	var exact bool
+	index := sort.Search(len(n.inodes), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(n.inodes[i].key, key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, n.inodes[index].pgid)
+}
+
+func (c *Cursor) searchPage(key []byte, p *page) {
+	// Binary search for the correct range.
+	inodes := p.branchPageElements()
+
+	var exact bool
+	index := sort.Search(int(p.count), func(i int) bool {
+		// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
+		// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
+		ret := bytes.Compare(inodes[i].key(), key)
+		if ret == 0 {
+			exact = true
+		}
+		return ret != -1
+	})
+	if !exact && index > 0 {
+		index--
+	}
+	c.stack[len(c.stack)-1].index = index
+
+	// Recursively search to the next page.
+	c.search(key, inodes[index].pgid)
+}
+
+// nsearch searches the leaf node on the top of the stack for a key.
+func (c *Cursor) nsearch(key []byte) {
+	e := &c.stack[len(c.stack)-1]
+	p, n := e.page, e.node
+
+	// If we have a node then search its inodes.
+	if n != nil {
+		index := sort.Search(len(n.inodes), func(i int) bool {
+			return bytes.Compare(n.inodes[i].key, key) != -1
+		})
+		e.index = index
+		return
+	}
+
+	// If we have a page then search its leaf elements.
+	inodes := p.leafPageElements()
+	index := sort.Search(int(p.count), func(i int) bool {
+		return bytes.Compare(inodes[i].key(), key) != -1
+	})
+	e.index = index
+}
+
+// keyValue returns the key and value of the current leaf element.
+func (c *Cursor) keyValue() ([]byte, []byte, uint32) {
+	ref := &c.stack[len(c.stack)-1]
+
+	// If the cursor is pointing to the end of page/node then return nil.
+	if ref.count() == 0 || ref.index >= ref.count() {
+		return nil, nil, 0
+	}
+
+	// Retrieve value from node.
+	if ref.node != nil {
+		inode := &ref.node.inodes[ref.index]
+		return inode.key, inode.value, inode.flags
+	}
+
+	// Or retrieve value from page.
+	elem := ref.page.leafPageElement(uint16(ref.index))
+	return elem.key(), elem.value(), elem.flags
+}
+
+// node returns the node that the cursor is currently positioned on.
+func (c *Cursor) node() *node {
+	_assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack")
+
+	// If the top of the stack is a leaf node then just return it.
+	if ref := &c.stack[len(c.stack)-1]; ref.node != nil && ref.isLeaf() {
+		return ref.node
+	}
+
+	// Start from root and traverse down the hierarchy.
+	var n = c.stack[0].node
+	if n == nil {
+		n = c.bucket.node(c.stack[0].page.id, nil)
+	}
+	for _, ref := range c.stack[:len(c.stack)-1] {
+		_assert(!n.isLeaf, "expected branch node")
+		n = n.childAt(int(ref.index))
+	}
+	_assert(n.isLeaf, "expected leaf node")
+	return n
+}
+
+// elemRef represents a reference to an element on a given page/node.
+type elemRef struct {
+	page  *page
+	node  *node
+	index int
+}
+
+// isLeaf returns whether the ref is pointing at a leaf page/node.
+func (r *elemRef) isLeaf() bool {
+	if r.node != nil {
+		return r.node.isLeaf
+	}
+	return (r.page.flags & leafPageFlag) != 0
+}
+
+// count returns the number of inodes or page elements.
+func (r *elemRef) count() int {
+	if r.node != nil {
+		return len(r.node.inodes)
+	}
+	return int(r.page.count)
+}
diff --git a/vendor/go.etcd.io/bbolt/db.go b/vendor/go.etcd.io/bbolt/db.go
new file mode 100644
index 0000000..870c8b1
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/db.go
@@ -0,0 +1,1174 @@
+package bbolt
+
+import (
+	"errors"
+	"fmt"
+	"hash/fnv"
+	"log"
+	"os"
+	"runtime"
+	"sort"
+	"sync"
+	"time"
+	"unsafe"
+)
+
+// The largest step that can be taken when remapping the mmap.
+const maxMmapStep = 1 << 30 // 1GB
+
+// The data file format version.
+const version = 2
+
+// Represents a marker value to indicate that a file is a Bolt DB.
+const magic uint32 = 0xED0CDAED
+
+const pgidNoFreelist pgid = 0xffffffffffffffff
+
+// IgnoreNoSync specifies whether the NoSync field of a DB is ignored when
+// syncing changes to a file.  This is required as some operating systems,
+// such as OpenBSD, do not have a unified buffer cache (UBC) and writes
+// must be synchronized using the msync(2) syscall.
+const IgnoreNoSync = runtime.GOOS == "openbsd"
+
+// Default values if not set in a DB instance.
+const (
+	DefaultMaxBatchSize  int = 1000
+	DefaultMaxBatchDelay     = 10 * time.Millisecond
+	DefaultAllocSize         = 16 * 1024 * 1024
+)
+
+// default page size for db is set to the OS page size.
+var defaultPageSize = os.Getpagesize()
+
+// The time elapsed between consecutive file locking attempts.
+const flockRetryTimeout = 50 * time.Millisecond
+
+// FreelistType is the type of the freelist backend
+type FreelistType string
+
+const (
+	// FreelistArrayType indicates backend freelist type is array
+	FreelistArrayType = FreelistType("array")
+	// FreelistMapType indicates backend freelist type is hashmap
+	FreelistMapType = FreelistType("hashmap")
+)
+
+// DB represents a collection of buckets persisted to a file on disk.
+// All data access is performed through transactions which can be obtained through the DB.
+// All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called.
+type DB struct {
+	// When enabled, the database will perform a Check() after every commit.
+	// A panic is issued if the database is in an inconsistent state. This
+	// flag has a large performance impact so it should only be used for
+	// debugging purposes.
+	StrictMode bool
+
+	// Setting the NoSync flag will cause the database to skip fsync()
+	// calls after each commit. This can be useful when bulk loading data
+	// into a database and you can restart the bulk load in the event of
+	// a system failure or database corruption. Do not set this flag for
+	// normal use.
+	//
+	// If the package global IgnoreNoSync constant is true, this value is
+	// ignored.  See the comment on that constant for more details.
+	//
+	// THIS IS UNSAFE. PLEASE USE WITH CAUTION.
+	NoSync bool
+
+	// When true, skips syncing freelist to disk. This improves the database
+	// write performance under normal operation, but requires a full database
+	// re-sync during recovery.
+	NoFreelistSync bool
+
+	// FreelistType sets the backend freelist type. There are two options. Array which is simple but endures
+	// dramatic performance degradation if database is large and framentation in freelist is common.
+	// The alternative one is using hashmap, it is faster in almost all circumstances
+	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
+	// The default type is array
+	FreelistType FreelistType
+
+	// When true, skips the truncate call when growing the database.
+	// Setting this to true is only safe on non-ext3/ext4 systems.
+	// Skipping truncation avoids preallocation of hard drive space and
+	// bypasses a truncate() and fsync() syscall on remapping.
+	//
+	// https://github.com/boltdb/bolt/issues/284
+	NoGrowSync bool
+
+	// If you want to read the entire database fast, you can set MmapFlag to
+	// syscall.MAP_POPULATE on Linux 2.6.23+ for sequential read-ahead.
+	MmapFlags int
+
+	// MaxBatchSize is the maximum size of a batch. Default value is
+	// copied from DefaultMaxBatchSize in Open.
+	//
+	// If <=0, disables batching.
+	//
+	// Do not change concurrently with calls to Batch.
+	MaxBatchSize int
+
+	// MaxBatchDelay is the maximum delay before a batch starts.
+	// Default value is copied from DefaultMaxBatchDelay in Open.
+	//
+	// If <=0, effectively disables batching.
+	//
+	// Do not change concurrently with calls to Batch.
+	MaxBatchDelay time.Duration
+
+	// AllocSize is the amount of space allocated when the database
+	// needs to create new pages. This is done to amortize the cost
+	// of truncate() and fsync() when growing the data file.
+	AllocSize int
+
+	path     string
+	openFile func(string, int, os.FileMode) (*os.File, error)
+	file     *os.File
+	dataref  []byte // mmap'ed readonly, write throws SEGV
+	data     *[maxMapSize]byte
+	datasz   int
+	filesz   int // current on disk file size
+	meta0    *meta
+	meta1    *meta
+	pageSize int
+	opened   bool
+	rwtx     *Tx
+	txs      []*Tx
+	stats    Stats
+
+	freelist     *freelist
+	freelistLoad sync.Once
+
+	pagePool sync.Pool
+
+	batchMu sync.Mutex
+	batch   *batch
+
+	rwlock   sync.Mutex   // Allows only one writer at a time.
+	metalock sync.Mutex   // Protects meta page access.
+	mmaplock sync.RWMutex // Protects mmap access during remapping.
+	statlock sync.RWMutex // Protects stats access.
+
+	ops struct {
+		writeAt func(b []byte, off int64) (n int, err error)
+	}
+
+	// Read only mode.
+	// When true, Update() and Begin(true) return ErrDatabaseReadOnly immediately.
+	readOnly bool
+}
+
+// Path returns the path to currently open database file.
+func (db *DB) Path() string {
+	return db.path
+}
+
+// GoString returns the Go string representation of the database.
+func (db *DB) GoString() string {
+	return fmt.Sprintf("bolt.DB{path:%q}", db.path)
+}
+
+// String returns the string representation of the database.
+func (db *DB) String() string {
+	return fmt.Sprintf("DB<%q>", db.path)
+}
+
+// Open creates and opens a database at the given path.
+// If the file does not exist then it will be created automatically.
+// Passing in nil options will cause Bolt to open the database with the default options.
+func Open(path string, mode os.FileMode, options *Options) (*DB, error) {
+	db := &DB{
+		opened: true,
+	}
+	// Set default options if no options are provided.
+	if options == nil {
+		options = DefaultOptions
+	}
+	db.NoSync = options.NoSync
+	db.NoGrowSync = options.NoGrowSync
+	db.MmapFlags = options.MmapFlags
+	db.NoFreelistSync = options.NoFreelistSync
+	db.FreelistType = options.FreelistType
+
+	// Set default values for later DB operations.
+	db.MaxBatchSize = DefaultMaxBatchSize
+	db.MaxBatchDelay = DefaultMaxBatchDelay
+	db.AllocSize = DefaultAllocSize
+
+	flag := os.O_RDWR
+	if options.ReadOnly {
+		flag = os.O_RDONLY
+		db.readOnly = true
+	}
+
+	db.openFile = options.OpenFile
+	if db.openFile == nil {
+		db.openFile = os.OpenFile
+	}
+
+	// Open data file and separate sync handler for metadata writes.
+	db.path = path
+	var err error
+	if db.file, err = db.openFile(db.path, flag|os.O_CREATE, mode); err != nil {
+		_ = db.close()
+		return nil, err
+	}
+
+	// Lock file so that other processes using Bolt in read-write mode cannot
+	// use the database  at the same time. This would cause corruption since
+	// the two processes would write meta pages and free pages separately.
+	// The database file is locked exclusively (only one process can grab the lock)
+	// if !options.ReadOnly.
+	// The database file is locked using the shared lock (more than one process may
+	// hold a lock at the same time) otherwise (options.ReadOnly is set).
+	if err := flock(db, !db.readOnly, options.Timeout); err != nil {
+		_ = db.close()
+		return nil, err
+	}
+
+	// Default values for test hooks
+	db.ops.writeAt = db.file.WriteAt
+
+	if db.pageSize = options.PageSize; db.pageSize == 0 {
+		// Set the default page size to the OS page size.
+		db.pageSize = defaultPageSize
+	}
+
+	// Initialize the database if it doesn't exist.
+	if info, err := db.file.Stat(); err != nil {
+		_ = db.close()
+		return nil, err
+	} else if info.Size() == 0 {
+		// Initialize new files with meta pages.
+		if err := db.init(); err != nil {
+			// clean up file descriptor on initialization fail
+			_ = db.close()
+			return nil, err
+		}
+	} else {
+		// Read the first meta page to determine the page size.
+		var buf [0x1000]byte
+		// If we can't read the page size, but can read a page, assume
+		// it's the same as the OS or one given -- since that's how the
+		// page size was chosen in the first place.
+		//
+		// If the first page is invalid and this OS uses a different
+		// page size than what the database was created with then we
+		// are out of luck and cannot access the database.
+		//
+		// TODO: scan for next page
+		if bw, err := db.file.ReadAt(buf[:], 0); err == nil && bw == len(buf) {
+			if m := db.pageInBuffer(buf[:], 0).meta(); m.validate() == nil {
+				db.pageSize = int(m.pageSize)
+			}
+		} else {
+			_ = db.close()
+			return nil, ErrInvalid
+		}
+	}
+
+	// Initialize page pool.
+	db.pagePool = sync.Pool{
+		New: func() interface{} {
+			return make([]byte, db.pageSize)
+		},
+	}
+
+	// Memory map the data file.
+	if err := db.mmap(options.InitialMmapSize); err != nil {
+		_ = db.close()
+		return nil, err
+	}
+
+	if db.readOnly {
+		return db, nil
+	}
+
+	db.loadFreelist()
+
+	// Flush freelist when transitioning from no sync to sync so
+	// NoFreelistSync unaware boltdb can open the db later.
+	if !db.NoFreelistSync && !db.hasSyncedFreelist() {
+		tx, err := db.Begin(true)
+		if tx != nil {
+			err = tx.Commit()
+		}
+		if err != nil {
+			_ = db.close()
+			return nil, err
+		}
+	}
+
+	// Mark the database as opened and return.
+	return db, nil
+}
+
+// loadFreelist reads the freelist if it is synced, or reconstructs it
+// by scanning the DB if it is not synced. It assumes there are no
+// concurrent accesses being made to the freelist.
+func (db *DB) loadFreelist() {
+	db.freelistLoad.Do(func() {
+		db.freelist = newFreelist(db.FreelistType)
+		if !db.hasSyncedFreelist() {
+			// Reconstruct free list by scanning the DB.
+			db.freelist.readIDs(db.freepages())
+		} else {
+			// Read free list from freelist page.
+			db.freelist.read(db.page(db.meta().freelist))
+		}
+		db.stats.FreePageN = db.freelist.free_count()
+	})
+}
+
+func (db *DB) hasSyncedFreelist() bool {
+	return db.meta().freelist != pgidNoFreelist
+}
+
+// mmap opens the underlying memory-mapped file and initializes the meta references.
+// minsz is the minimum size that the new mmap can be.
+func (db *DB) mmap(minsz int) error {
+	db.mmaplock.Lock()
+	defer db.mmaplock.Unlock()
+
+	info, err := db.file.Stat()
+	if err != nil {
+		return fmt.Errorf("mmap stat error: %s", err)
+	} else if int(info.Size()) < db.pageSize*2 {
+		return fmt.Errorf("file size too small")
+	}
+
+	// Ensure the size is at least the minimum size.
+	var size = int(info.Size())
+	if size < minsz {
+		size = minsz
+	}
+	size, err = db.mmapSize(size)
+	if err != nil {
+		return err
+	}
+
+	// Dereference all mmap references before unmapping.
+	if db.rwtx != nil {
+		db.rwtx.root.dereference()
+	}
+
+	// Unmap existing data before continuing.
+	if err := db.munmap(); err != nil {
+		return err
+	}
+
+	// Memory-map the data file as a byte slice.
+	if err := mmap(db, size); err != nil {
+		return err
+	}
+
+	// Save references to the meta pages.
+	db.meta0 = db.page(0).meta()
+	db.meta1 = db.page(1).meta()
+
+	// Validate the meta pages. We only return an error if both meta pages fail
+	// validation, since meta0 failing validation means that it wasn't saved
+	// properly -- but we can recover using meta1. And vice-versa.
+	err0 := db.meta0.validate()
+	err1 := db.meta1.validate()
+	if err0 != nil && err1 != nil {
+		return err0
+	}
+
+	return nil
+}
+
+// munmap unmaps the data file from memory.
+func (db *DB) munmap() error {
+	if err := munmap(db); err != nil {
+		return fmt.Errorf("unmap error: " + err.Error())
+	}
+	return nil
+}
+
+// mmapSize determines the appropriate size for the mmap given the current size
+// of the database. The minimum size is 32KB and doubles until it reaches 1GB.
+// Returns an error if the new mmap size is greater than the max allowed.
+func (db *DB) mmapSize(size int) (int, error) {
+	// Double the size from 32KB until 1GB.
+	for i := uint(15); i <= 30; i++ {
+		if size <= 1<<i {
+			return 1 << i, nil
+		}
+	}
+
+	// Verify the requested size is not above the maximum allowed.
+	if size > maxMapSize {
+		return 0, fmt.Errorf("mmap too large")
+	}
+
+	// If larger than 1GB then grow by 1GB at a time.
+	sz := int64(size)
+	if remainder := sz % int64(maxMmapStep); remainder > 0 {
+		sz += int64(maxMmapStep) - remainder
+	}
+
+	// Ensure that the mmap size is a multiple of the page size.
+	// This should always be true since we're incrementing in MBs.
+	pageSize := int64(db.pageSize)
+	if (sz % pageSize) != 0 {
+		sz = ((sz / pageSize) + 1) * pageSize
+	}
+
+	// If we've exceeded the max size then only grow up to the max size.
+	if sz > maxMapSize {
+		sz = maxMapSize
+	}
+
+	return int(sz), nil
+}
+
+// init creates a new database file and initializes its meta pages.
+func (db *DB) init() error {
+	// Create two meta pages on a buffer.
+	buf := make([]byte, db.pageSize*4)
+	for i := 0; i < 2; i++ {
+		p := db.pageInBuffer(buf[:], pgid(i))
+		p.id = pgid(i)
+		p.flags = metaPageFlag
+
+		// Initialize the meta page.
+		m := p.meta()
+		m.magic = magic
+		m.version = version
+		m.pageSize = uint32(db.pageSize)
+		m.freelist = 2
+		m.root = bucket{root: 3}
+		m.pgid = 4
+		m.txid = txid(i)
+		m.checksum = m.sum64()
+	}
+
+	// Write an empty freelist at page 3.
+	p := db.pageInBuffer(buf[:], pgid(2))
+	p.id = pgid(2)
+	p.flags = freelistPageFlag
+	p.count = 0
+
+	// Write an empty leaf page at page 4.
+	p = db.pageInBuffer(buf[:], pgid(3))
+	p.id = pgid(3)
+	p.flags = leafPageFlag
+	p.count = 0
+
+	// Write the buffer to our data file.
+	if _, err := db.ops.writeAt(buf, 0); err != nil {
+		return err
+	}
+	if err := fdatasync(db); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Close releases all database resources.
+// It will block waiting for any open transactions to finish
+// before closing the database and returning.
+func (db *DB) Close() error {
+	db.rwlock.Lock()
+	defer db.rwlock.Unlock()
+
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
+	db.mmaplock.Lock()
+	defer db.mmaplock.Unlock()
+
+	return db.close()
+}
+
+func (db *DB) close() error {
+	if !db.opened {
+		return nil
+	}
+
+	db.opened = false
+
+	db.freelist = nil
+
+	// Clear ops.
+	db.ops.writeAt = nil
+
+	// Close the mmap.
+	if err := db.munmap(); err != nil {
+		return err
+	}
+
+	// Close file handles.
+	if db.file != nil {
+		// No need to unlock read-only file.
+		if !db.readOnly {
+			// Unlock the file.
+			if err := funlock(db); err != nil {
+				log.Printf("bolt.Close(): funlock error: %s", err)
+			}
+		}
+
+		// Close the file descriptor.
+		if err := db.file.Close(); err != nil {
+			return fmt.Errorf("db file close: %s", err)
+		}
+		db.file = nil
+	}
+
+	db.path = ""
+	return nil
+}
+
+// Begin starts a new transaction.
+// Multiple read-only transactions can be used concurrently but only one
+// write transaction can be used at a time. Starting multiple write transactions
+// will cause the calls to block and be serialized until the current write
+// transaction finishes.
+//
+// Transactions should not be dependent on one another. Opening a read
+// transaction and a write transaction in the same goroutine can cause the
+// writer to deadlock because the database periodically needs to re-mmap itself
+// as it grows and it cannot do that while a read transaction is open.
+//
+// If a long running read transaction (for example, a snapshot transaction) is
+// needed, you might want to set DB.InitialMmapSize to a large enough value
+// to avoid potential blocking of write transaction.
+//
+// IMPORTANT: You must close read-only transactions after you are finished or
+// else the database will not reclaim old pages.
+func (db *DB) Begin(writable bool) (*Tx, error) {
+	if writable {
+		return db.beginRWTx()
+	}
+	return db.beginTx()
+}
+
+func (db *DB) beginTx() (*Tx, error) {
+	// Lock the meta pages while we initialize the transaction. We obtain
+	// the meta lock before the mmap lock because that's the order that the
+	// write transaction will obtain them.
+	db.metalock.Lock()
+
+	// Obtain a read-only lock on the mmap. When the mmap is remapped it will
+	// obtain a write lock so all transactions must finish before it can be
+	// remapped.
+	db.mmaplock.RLock()
+
+	// Exit if the database is not open yet.
+	if !db.opened {
+		db.mmaplock.RUnlock()
+		db.metalock.Unlock()
+		return nil, ErrDatabaseNotOpen
+	}
+
+	// Create a transaction associated with the database.
+	t := &Tx{}
+	t.init(db)
+
+	// Keep track of transaction until it closes.
+	db.txs = append(db.txs, t)
+	n := len(db.txs)
+
+	// Unlock the meta pages.
+	db.metalock.Unlock()
+
+	// Update the transaction stats.
+	db.statlock.Lock()
+	db.stats.TxN++
+	db.stats.OpenTxN = n
+	db.statlock.Unlock()
+
+	return t, nil
+}
+
+func (db *DB) beginRWTx() (*Tx, error) {
+	// If the database was opened with Options.ReadOnly, return an error.
+	if db.readOnly {
+		return nil, ErrDatabaseReadOnly
+	}
+
+	// Obtain writer lock. This is released by the transaction when it closes.
+	// This enforces only one writer transaction at a time.
+	db.rwlock.Lock()
+
+	// Once we have the writer lock then we can lock the meta pages so that
+	// we can set up the transaction.
+	db.metalock.Lock()
+	defer db.metalock.Unlock()
+
+	// Exit if the database is not open yet.
+	if !db.opened {
+		db.rwlock.Unlock()
+		return nil, ErrDatabaseNotOpen
+	}
+
+	// Create a transaction associated with the database.
+	t := &Tx{writable: true}
+	t.init(db)
+	db.rwtx = t
+	db.freePages()
+	return t, nil
+}
+
+// freePages releases any pages associated with closed read-only transactions.
+func (db *DB) freePages() {
+	// Free all pending pages prior to earliest open transaction.
+	sort.Sort(txsById(db.txs))
+	minid := txid(0xFFFFFFFFFFFFFFFF)
+	if len(db.txs) > 0 {
+		minid = db.txs[0].meta.txid
+	}
+	if minid > 0 {
+		db.freelist.release(minid - 1)
+	}
+	// Release unused txid extents.
+	for _, t := range db.txs {
+		db.freelist.releaseRange(minid, t.meta.txid-1)
+		minid = t.meta.txid + 1
+	}
+	db.freelist.releaseRange(minid, txid(0xFFFFFFFFFFFFFFFF))
+	// Any page both allocated and freed in an extent is safe to release.
+}
+
+type txsById []*Tx
+
+func (t txsById) Len() int           { return len(t) }
+func (t txsById) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
+func (t txsById) Less(i, j int) bool { return t[i].meta.txid < t[j].meta.txid }
+
+// removeTx removes a transaction from the database.
+func (db *DB) removeTx(tx *Tx) {
+	// Release the read lock on the mmap.
+	db.mmaplock.RUnlock()
+
+	// Use the meta lock to restrict access to the DB object.
+	db.metalock.Lock()
+
+	// Remove the transaction.
+	for i, t := range db.txs {
+		if t == tx {
+			last := len(db.txs) - 1
+			db.txs[i] = db.txs[last]
+			db.txs[last] = nil
+			db.txs = db.txs[:last]
+			break
+		}
+	}
+	n := len(db.txs)
+
+	// Unlock the meta pages.
+	db.metalock.Unlock()
+
+	// Merge statistics.
+	db.statlock.Lock()
+	db.stats.OpenTxN = n
+	db.stats.TxStats.add(&tx.stats)
+	db.statlock.Unlock()
+}
+
+// Update executes a function within the context of a read-write managed transaction.
+// If no error is returned from the function then the transaction is committed.
+// If an error is returned then the entire transaction is rolled back.
+// Any error that is returned from the function or returned from the commit is
+// returned from the Update() method.
+//
+// Attempting to manually commit or rollback within the function will cause a panic.
+func (db *DB) Update(fn func(*Tx) error) error {
+	t, err := db.Begin(true)
+	if err != nil {
+		return err
+	}
+
+	// Make sure the transaction rolls back in the event of a panic.
+	defer func() {
+		if t.db != nil {
+			t.rollback()
+		}
+	}()
+
+	// Mark as a managed tx so that the inner function cannot manually commit.
+	t.managed = true
+
+	// If an error is returned from the function then rollback and return error.
+	err = fn(t)
+	t.managed = false
+	if err != nil {
+		_ = t.Rollback()
+		return err
+	}
+
+	return t.Commit()
+}
+
+// View executes a function within the context of a managed read-only transaction.
+// Any error that is returned from the function is returned from the View() method.
+//
+// Attempting to manually rollback within the function will cause a panic.
+func (db *DB) View(fn func(*Tx) error) error {
+	t, err := db.Begin(false)
+	if err != nil {
+		return err
+	}
+
+	// Make sure the transaction rolls back in the event of a panic.
+	defer func() {
+		if t.db != nil {
+			t.rollback()
+		}
+	}()
+
+	// Mark as a managed tx so that the inner function cannot manually rollback.
+	t.managed = true
+
+	// If an error is returned from the function then pass it through.
+	err = fn(t)
+	t.managed = false
+	if err != nil {
+		_ = t.Rollback()
+		return err
+	}
+
+	return t.Rollback()
+}
+
+// Batch calls fn as part of a batch. It behaves similar to Update,
+// except:
+//
+// 1. concurrent Batch calls can be combined into a single Bolt
+// transaction.
+//
+// 2. the function passed to Batch may be called multiple times,
+// regardless of whether it returns error or not.
+//
+// This means that Batch function side effects must be idempotent and
+// take permanent effect only after a successful return is seen in
+// caller.
+//
+// The maximum batch size and delay can be adjusted with DB.MaxBatchSize
+// and DB.MaxBatchDelay, respectively.
+//
+// Batch is only useful when there are multiple goroutines calling it.
+func (db *DB) Batch(fn func(*Tx) error) error {
+	errCh := make(chan error, 1)
+
+	db.batchMu.Lock()
+	if (db.batch == nil) || (db.batch != nil && len(db.batch.calls) >= db.MaxBatchSize) {
+		// There is no existing batch, or the existing batch is full; start a new one.
+		db.batch = &batch{
+			db: db,
+		}
+		db.batch.timer = time.AfterFunc(db.MaxBatchDelay, db.batch.trigger)
+	}
+	db.batch.calls = append(db.batch.calls, call{fn: fn, err: errCh})
+	if len(db.batch.calls) >= db.MaxBatchSize {
+		// wake up batch, it's ready to run
+		go db.batch.trigger()
+	}
+	db.batchMu.Unlock()
+
+	err := <-errCh
+	if err == trySolo {
+		err = db.Update(fn)
+	}
+	return err
+}
+
+type call struct {
+	fn  func(*Tx) error
+	err chan<- error
+}
+
+type batch struct {
+	db    *DB
+	timer *time.Timer
+	start sync.Once
+	calls []call
+}
+
+// trigger runs the batch if it hasn't already been run.
+func (b *batch) trigger() {
+	b.start.Do(b.run)
+}
+
+// run performs the transactions in the batch and communicates results
+// back to DB.Batch.
+func (b *batch) run() {
+	b.db.batchMu.Lock()
+	b.timer.Stop()
+	// Make sure no new work is added to this batch, but don't break
+	// other batches.
+	if b.db.batch == b {
+		b.db.batch = nil
+	}
+	b.db.batchMu.Unlock()
+
+retry:
+	for len(b.calls) > 0 {
+		var failIdx = -1
+		err := b.db.Update(func(tx *Tx) error {
+			for i, c := range b.calls {
+				if err := safelyCall(c.fn, tx); err != nil {
+					failIdx = i
+					return err
+				}
+			}
+			return nil
+		})
+
+		if failIdx >= 0 {
+			// take the failing transaction out of the batch. it's
+			// safe to shorten b.calls here because db.batch no longer
+			// points to us, and we hold the mutex anyway.
+			c := b.calls[failIdx]
+			b.calls[failIdx], b.calls = b.calls[len(b.calls)-1], b.calls[:len(b.calls)-1]
+			// tell the submitter re-run it solo, continue with the rest of the batch
+			c.err <- trySolo
+			continue retry
+		}
+
+		// pass success, or bolt internal errors, to all callers
+		for _, c := range b.calls {
+			c.err <- err
+		}
+		break retry
+	}
+}
+
+// trySolo is a special sentinel error value used for signaling that a
+// transaction function should be re-run. It should never be seen by
+// callers.
+var trySolo = errors.New("batch function returned an error and should be re-run solo")
+
+type panicked struct {
+	reason interface{}
+}
+
+func (p panicked) Error() string {
+	if err, ok := p.reason.(error); ok {
+		return err.Error()
+	}
+	return fmt.Sprintf("panic: %v", p.reason)
+}
+
+func safelyCall(fn func(*Tx) error, tx *Tx) (err error) {
+	defer func() {
+		if p := recover(); p != nil {
+			err = panicked{p}
+		}
+	}()
+	return fn(tx)
+}
+
+// Sync executes fdatasync() against the database file handle.
+//
+// This is not necessary under normal operation, however, if you use NoSync
+// then it allows you to force the database file to sync against the disk.
+func (db *DB) Sync() error { return fdatasync(db) }
+
+// Stats retrieves ongoing performance stats for the database.
+// This is only updated when a transaction closes.
+func (db *DB) Stats() Stats {
+	db.statlock.RLock()
+	defer db.statlock.RUnlock()
+	return db.stats
+}
+
+// This is for internal access to the raw data bytes from the C cursor, use
+// carefully, or not at all.
+func (db *DB) Info() *Info {
+	return &Info{uintptr(unsafe.Pointer(&db.data[0])), db.pageSize}
+}
+
+// page retrieves a page reference from the mmap based on the current page size.
+func (db *DB) page(id pgid) *page {
+	pos := id * pgid(db.pageSize)
+	return (*page)(unsafe.Pointer(&db.data[pos]))
+}
+
+// pageInBuffer retrieves a page reference from a given byte array based on the current page size.
+func (db *DB) pageInBuffer(b []byte, id pgid) *page {
+	return (*page)(unsafe.Pointer(&b[id*pgid(db.pageSize)]))
+}
+
+// meta retrieves the current meta page reference.
+func (db *DB) meta() *meta {
+	// We have to return the meta with the highest txid which doesn't fail
+	// validation. Otherwise, we can cause errors when in fact the database is
+	// in a consistent state. metaA is the one with the higher txid.
+	metaA := db.meta0
+	metaB := db.meta1
+	if db.meta1.txid > db.meta0.txid {
+		metaA = db.meta1
+		metaB = db.meta0
+	}
+
+	// Use higher meta page if valid. Otherwise fallback to previous, if valid.
+	if err := metaA.validate(); err == nil {
+		return metaA
+	} else if err := metaB.validate(); err == nil {
+		return metaB
+	}
+
+	// This should never be reached, because both meta1 and meta0 were validated
+	// on mmap() and we do fsync() on every write.
+	panic("bolt.DB.meta(): invalid meta pages")
+}
+
+// allocate returns a contiguous block of memory starting at a given page.
+func (db *DB) allocate(txid txid, count int) (*page, error) {
+	// Allocate a temporary buffer for the page.
+	var buf []byte
+	if count == 1 {
+		buf = db.pagePool.Get().([]byte)
+	} else {
+		buf = make([]byte, count*db.pageSize)
+	}
+	p := (*page)(unsafe.Pointer(&buf[0]))
+	p.overflow = uint32(count - 1)
+
+	// Use pages from the freelist if they are available.
+	if p.id = db.freelist.allocate(txid, count); p.id != 0 {
+		return p, nil
+	}
+
+	// Resize mmap() if we're at the end.
+	p.id = db.rwtx.meta.pgid
+	var minsz = int((p.id+pgid(count))+1) * db.pageSize
+	if minsz >= db.datasz {
+		if err := db.mmap(minsz); err != nil {
+			return nil, fmt.Errorf("mmap allocate error: %s", err)
+		}
+	}
+
+	// Move the page id high water mark.
+	db.rwtx.meta.pgid += pgid(count)
+
+	return p, nil
+}
+
+// grow grows the size of the database to the given sz.
+func (db *DB) grow(sz int) error {
+	// Ignore if the new size is less than available file size.
+	if sz <= db.filesz {
+		return nil
+	}
+
+	// If the data is smaller than the alloc size then only allocate what's needed.
+	// Once it goes over the allocation size then allocate in chunks.
+	if db.datasz < db.AllocSize {
+		sz = db.datasz
+	} else {
+		sz += db.AllocSize
+	}
+
+	// Truncate and fsync to ensure file size metadata is flushed.
+	// https://github.com/boltdb/bolt/issues/284
+	if !db.NoGrowSync && !db.readOnly {
+		if runtime.GOOS != "windows" {
+			if err := db.file.Truncate(int64(sz)); err != nil {
+				return fmt.Errorf("file resize error: %s", err)
+			}
+		}
+		if err := db.file.Sync(); err != nil {
+			return fmt.Errorf("file sync error: %s", err)
+		}
+	}
+
+	db.filesz = sz
+	return nil
+}
+
+func (db *DB) IsReadOnly() bool {
+	return db.readOnly
+}
+
+func (db *DB) freepages() []pgid {
+	tx, err := db.beginTx()
+	defer func() {
+		err = tx.Rollback()
+		if err != nil {
+			panic("freepages: failed to rollback tx")
+		}
+	}()
+	if err != nil {
+		panic("freepages: failed to open read only tx")
+	}
+
+	reachable := make(map[pgid]*page)
+	nofreed := make(map[pgid]bool)
+	ech := make(chan error)
+	go func() {
+		for e := range ech {
+			panic(fmt.Sprintf("freepages: failed to get all reachable pages (%v)", e))
+		}
+	}()
+	tx.checkBucket(&tx.root, reachable, nofreed, ech)
+	close(ech)
+
+	var fids []pgid
+	for i := pgid(2); i < db.meta().pgid; i++ {
+		if _, ok := reachable[i]; !ok {
+			fids = append(fids, i)
+		}
+	}
+	return fids
+}
+
+// Options represents the options that can be set when opening a database.
+type Options struct {
+	// Timeout is the amount of time to wait to obtain a file lock.
+	// When set to zero it will wait indefinitely. This option is only
+	// available on Darwin and Linux.
+	Timeout time.Duration
+
+	// Sets the DB.NoGrowSync flag before memory mapping the file.
+	NoGrowSync bool
+
+	// Do not sync freelist to disk. This improves the database write performance
+	// under normal operation, but requires a full database re-sync during recovery.
+	NoFreelistSync bool
+
+	// FreelistType sets the backend freelist type. There are two options. Array which is simple but endures
+	// dramatic performance degradation if database is large and framentation in freelist is common.
+	// The alternative one is using hashmap, it is faster in almost all circumstances
+	// but it doesn't guarantee that it offers the smallest page id available. In normal case it is safe.
+	// The default type is array
+	FreelistType FreelistType
+
+	// Open database in read-only mode. Uses flock(..., LOCK_SH |LOCK_NB) to
+	// grab a shared lock (UNIX).
+	ReadOnly bool
+
+	// Sets the DB.MmapFlags flag before memory mapping the file.
+	MmapFlags int
+
+	// InitialMmapSize is the initial mmap size of the database
+	// in bytes. Read transactions won't block write transaction
+	// if the InitialMmapSize is large enough to hold database mmap
+	// size. (See DB.Begin for more information)
+	//
+	// If <=0, the initial map size is 0.
+	// If initialMmapSize is smaller than the previous database size,
+	// it takes no effect.
+	InitialMmapSize int
+
+	// PageSize overrides the default OS page size.
+	PageSize int
+
+	// NoSync sets the initial value of DB.NoSync. Normally this can just be
+	// set directly on the DB itself when returned from Open(), but this option
+	// is useful in APIs which expose Options but not the underlying DB.
+	NoSync bool
+
+	// OpenFile is used to open files. It defaults to os.OpenFile. This option
+	// is useful for writing hermetic tests.
+	OpenFile func(string, int, os.FileMode) (*os.File, error)
+}
+
+// DefaultOptions represent the options used if nil options are passed into Open().
+// No timeout is used which will cause Bolt to wait indefinitely for a lock.
+var DefaultOptions = &Options{
+	Timeout:      0,
+	NoGrowSync:   false,
+	FreelistType: FreelistArrayType,
+}
+
+// Stats represents statistics about the database.
+type Stats struct {
+	// Freelist stats
+	FreePageN     int // total number of free pages on the freelist
+	PendingPageN  int // total number of pending pages on the freelist
+	FreeAlloc     int // total bytes allocated in free pages
+	FreelistInuse int // total bytes used by the freelist
+
+	// Transaction stats
+	TxN     int // total number of started read transactions
+	OpenTxN int // number of currently open read transactions
+
+	TxStats TxStats // global, ongoing stats.
+}
+
+// Sub calculates and returns the difference between two sets of database stats.
+// This is useful when obtaining stats at two different points and time and
+// you need the performance counters that occurred within that time span.
+func (s *Stats) Sub(other *Stats) Stats {
+	if other == nil {
+		return *s
+	}
+	var diff Stats
+	diff.FreePageN = s.FreePageN
+	diff.PendingPageN = s.PendingPageN
+	diff.FreeAlloc = s.FreeAlloc
+	diff.FreelistInuse = s.FreelistInuse
+	diff.TxN = s.TxN - other.TxN
+	diff.TxStats = s.TxStats.Sub(&other.TxStats)
+	return diff
+}
+
+type Info struct {
+	Data     uintptr
+	PageSize int
+}
+
+type meta struct {
+	magic    uint32
+	version  uint32
+	pageSize uint32
+	flags    uint32
+	root     bucket
+	freelist pgid
+	pgid     pgid
+	txid     txid
+	checksum uint64
+}
+
+// validate checks the marker bytes and version of the meta page to ensure it matches this binary.
+func (m *meta) validate() error {
+	if m.magic != magic {
+		return ErrInvalid
+	} else if m.version != version {
+		return ErrVersionMismatch
+	} else if m.checksum != 0 && m.checksum != m.sum64() {
+		return ErrChecksum
+	}
+	return nil
+}
+
+// copy copies one meta object to another.
+func (m *meta) copy(dest *meta) {
+	*dest = *m
+}
+
+// write writes the meta onto a page.
+func (m *meta) write(p *page) {
+	if m.root.root >= m.pgid {
+		panic(fmt.Sprintf("root bucket pgid (%d) above high water mark (%d)", m.root.root, m.pgid))
+	} else if m.freelist >= m.pgid && m.freelist != pgidNoFreelist {
+		// TODO: reject pgidNoFreeList if !NoFreelistSync
+		panic(fmt.Sprintf("freelist pgid (%d) above high water mark (%d)", m.freelist, m.pgid))
+	}
+
+	// Page id is either going to be 0 or 1 which we can determine by the transaction ID.
+	p.id = pgid(m.txid % 2)
+	p.flags |= metaPageFlag
+
+	// Calculate the checksum.
+	m.checksum = m.sum64()
+
+	m.copy(p.meta())
+}
+
+// generates the checksum for the meta.
+func (m *meta) sum64() uint64 {
+	var h = fnv.New64a()
+	_, _ = h.Write((*[unsafe.Offsetof(meta{}.checksum)]byte)(unsafe.Pointer(m))[:])
+	return h.Sum64()
+}
+
+// _assert will panic with a given formatted message if the given condition is false.
+func _assert(condition bool, msg string, v ...interface{}) {
+	if !condition {
+		panic(fmt.Sprintf("assertion failed: "+msg, v...))
+	}
+}
diff --git a/vendor/go.etcd.io/bbolt/doc.go b/vendor/go.etcd.io/bbolt/doc.go
new file mode 100644
index 0000000..95f25f0
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/doc.go
@@ -0,0 +1,44 @@
+/*
+package bbolt implements a low-level key/value store in pure Go. It supports
+fully serializable transactions, ACID semantics, and lock-free MVCC with
+multiple readers and a single writer. Bolt can be used for projects that
+want a simple data store without the need to add large dependencies such as
+Postgres or MySQL.
+
+Bolt is a single-level, zero-copy, B+tree data store. This means that Bolt is
+optimized for fast read access and does not require recovery in the event of a
+system crash. Transactions which have not finished committing will simply be
+rolled back in the event of a crash.
+
+The design of Bolt is based on Howard Chu's LMDB database project.
+
+Bolt currently works on Windows, Mac OS X, and Linux.
+
+
+Basics
+
+There are only a few types in Bolt: DB, Bucket, Tx, and Cursor. The DB is
+a collection of buckets and is represented by a single file on disk. A bucket is
+a collection of unique keys that are associated with values.
+
+Transactions provide either read-only or read-write access to the database.
+Read-only transactions can retrieve key/value pairs and can use Cursors to
+iterate over the dataset sequentially. Read-write transactions can create and
+delete buckets and can insert and remove keys. Only one read-write transaction
+is allowed at a time.
+
+
+Caveats
+
+The database uses a read-only, memory-mapped data file to ensure that
+applications cannot corrupt the database, however, this means that keys and
+values returned from Bolt cannot be changed. Writing to a read-only byte slice
+will cause Go to panic.
+
+Keys and values retrieved from the database are only valid for the life of
+the transaction. When used outside the transaction, these byte slices can
+point to different data or can point to invalid memory which will cause a panic.
+
+
+*/
+package bbolt
diff --git a/vendor/go.etcd.io/bbolt/errors.go b/vendor/go.etcd.io/bbolt/errors.go
new file mode 100644
index 0000000..48758ca
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/errors.go
@@ -0,0 +1,71 @@
+package bbolt
+
+import "errors"
+
+// These errors can be returned when opening or calling methods on a DB.
+var (
+	// ErrDatabaseNotOpen is returned when a DB instance is accessed before it
+	// is opened or after it is closed.
+	ErrDatabaseNotOpen = errors.New("database not open")
+
+	// ErrDatabaseOpen is returned when opening a database that is
+	// already open.
+	ErrDatabaseOpen = errors.New("database already open")
+
+	// ErrInvalid is returned when both meta pages on a database are invalid.
+	// This typically occurs when a file is not a bolt database.
+	ErrInvalid = errors.New("invalid database")
+
+	// ErrVersionMismatch is returned when the data file was created with a
+	// different version of Bolt.
+	ErrVersionMismatch = errors.New("version mismatch")
+
+	// ErrChecksum is returned when either meta page checksum does not match.
+	ErrChecksum = errors.New("checksum error")
+
+	// ErrTimeout is returned when a database cannot obtain an exclusive lock
+	// on the data file after the timeout passed to Open().
+	ErrTimeout = errors.New("timeout")
+)
+
+// These errors can occur when beginning or committing a Tx.
+var (
+	// ErrTxNotWritable is returned when performing a write operation on a
+	// read-only transaction.
+	ErrTxNotWritable = errors.New("tx not writable")
+
+	// ErrTxClosed is returned when committing or rolling back a transaction
+	// that has already been committed or rolled back.
+	ErrTxClosed = errors.New("tx closed")
+
+	// ErrDatabaseReadOnly is returned when a mutating transaction is started on a
+	// read-only database.
+	ErrDatabaseReadOnly = errors.New("database is in read-only mode")
+)
+
+// These errors can occur when putting or deleting a value or a bucket.
+var (
+	// ErrBucketNotFound is returned when trying to access a bucket that has
+	// not been created yet.
+	ErrBucketNotFound = errors.New("bucket not found")
+
+	// ErrBucketExists is returned when creating a bucket that already exists.
+	ErrBucketExists = errors.New("bucket already exists")
+
+	// ErrBucketNameRequired is returned when creating a bucket with a blank name.
+	ErrBucketNameRequired = errors.New("bucket name required")
+
+	// ErrKeyRequired is returned when inserting a zero-length key.
+	ErrKeyRequired = errors.New("key required")
+
+	// ErrKeyTooLarge is returned when inserting a key that is larger than MaxKeySize.
+	ErrKeyTooLarge = errors.New("key too large")
+
+	// ErrValueTooLarge is returned when inserting a value that is larger than MaxValueSize.
+	ErrValueTooLarge = errors.New("value too large")
+
+	// ErrIncompatibleValue is returned when trying create or delete a bucket
+	// on an existing non-bucket key or when trying to create or delete a
+	// non-bucket key on an existing bucket key.
+	ErrIncompatibleValue = errors.New("incompatible value")
+)
diff --git a/vendor/go.etcd.io/bbolt/freelist.go b/vendor/go.etcd.io/bbolt/freelist.go
new file mode 100644
index 0000000..587b8cc
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/freelist.go
@@ -0,0 +1,392 @@
+package bbolt
+
+import (
+	"fmt"
+	"sort"
+	"unsafe"
+)
+
+// txPending holds a list of pgids and corresponding allocation txns
+// that are pending to be freed.
+type txPending struct {
+	ids              []pgid
+	alloctx          []txid // txids allocating the ids
+	lastReleaseBegin txid   // beginning txid of last matching releaseRange
+}
+
+// pidSet holds the set of starting pgids which have the same span size
+type pidSet map[pgid]struct{}
+
+// freelist represents a list of all pages that are available for allocation.
+// It also tracks pages that have been freed but are still in use by open transactions.
+type freelist struct {
+	freelistType   FreelistType                // freelist type
+	ids            []pgid                      // all free and available free page ids.
+	allocs         map[pgid]txid               // mapping of txid that allocated a pgid.
+	pending        map[txid]*txPending         // mapping of soon-to-be free page ids by tx.
+	cache          map[pgid]bool               // fast lookup of all free and pending page ids.
+	freemaps       map[uint64]pidSet           // key is the size of continuous pages(span), value is a set which contains the starting pgids of same size
+	forwardMap     map[pgid]uint64             // key is start pgid, value is its span size
+	backwardMap    map[pgid]uint64             // key is end pgid, value is its span size
+	allocate       func(txid txid, n int) pgid // the freelist allocate func
+	free_count     func() int                  // the function which gives you free page number
+	mergeSpans     func(ids pgids)             // the mergeSpan func
+	getFreePageIDs func() []pgid               // get free pgids func
+	readIDs        func(pgids []pgid)          // readIDs func reads list of pages and init the freelist
+}
+
+// newFreelist returns an empty, initialized freelist.
+func newFreelist(freelistType FreelistType) *freelist {
+	f := &freelist{
+		freelistType: freelistType,
+		allocs:       make(map[pgid]txid),
+		pending:      make(map[txid]*txPending),
+		cache:        make(map[pgid]bool),
+		freemaps:     make(map[uint64]pidSet),
+		forwardMap:   make(map[pgid]uint64),
+		backwardMap:  make(map[pgid]uint64),
+	}
+
+	if freelistType == FreelistMapType {
+		f.allocate = f.hashmapAllocate
+		f.free_count = f.hashmapFreeCount
+		f.mergeSpans = f.hashmapMergeSpans
+		f.getFreePageIDs = f.hashmapGetFreePageIDs
+		f.readIDs = f.hashmapReadIDs
+	} else {
+		f.allocate = f.arrayAllocate
+		f.free_count = f.arrayFreeCount
+		f.mergeSpans = f.arrayMergeSpans
+		f.getFreePageIDs = f.arrayGetFreePageIDs
+		f.readIDs = f.arrayReadIDs
+	}
+
+	return f
+}
+
+// size returns the size of the page after serialization.
+func (f *freelist) size() int {
+	n := f.count()
+	if n >= 0xFFFF {
+		// The first element will be used to store the count. See freelist.write.
+		n++
+	}
+	return pageHeaderSize + (int(unsafe.Sizeof(pgid(0))) * n)
+}
+
+// count returns count of pages on the freelist
+func (f *freelist) count() int {
+	return f.free_count() + f.pending_count()
+}
+
+// arrayFreeCount returns count of free pages(array version)
+func (f *freelist) arrayFreeCount() int {
+	return len(f.ids)
+}
+
+// pending_count returns count of pending pages
+func (f *freelist) pending_count() int {
+	var count int
+	for _, txp := range f.pending {
+		count += len(txp.ids)
+	}
+	return count
+}
+
+// copyall copies into dst a list of all free ids and all pending ids in one sorted list.
+// f.count returns the minimum length required for dst.
+func (f *freelist) copyall(dst []pgid) {
+	m := make(pgids, 0, f.pending_count())
+	for _, txp := range f.pending {
+		m = append(m, txp.ids...)
+	}
+	sort.Sort(m)
+	mergepgids(dst, f.getFreePageIDs(), m)
+}
+
+// arrayAllocate returns the starting page id of a contiguous list of pages of a given size.
+// If a contiguous block cannot be found then 0 is returned.
+func (f *freelist) arrayAllocate(txid txid, n int) pgid {
+	if len(f.ids) == 0 {
+		return 0
+	}
+
+	var initial, previd pgid
+	for i, id := range f.ids {
+		if id <= 1 {
+			panic(fmt.Sprintf("invalid page allocation: %d", id))
+		}
+
+		// Reset initial page if this is not contiguous.
+		if previd == 0 || id-previd != 1 {
+			initial = id
+		}
+
+		// If we found a contiguous block then remove it and return it.
+		if (id-initial)+1 == pgid(n) {
+			// If we're allocating off the beginning then take the fast path
+			// and just adjust the existing slice. This will use extra memory
+			// temporarily but the append() in free() will realloc the slice
+			// as is necessary.
+			if (i + 1) == n {
+				f.ids = f.ids[i+1:]
+			} else {
+				copy(f.ids[i-n+1:], f.ids[i+1:])
+				f.ids = f.ids[:len(f.ids)-n]
+			}
+
+			// Remove from the free cache.
+			for i := pgid(0); i < pgid(n); i++ {
+				delete(f.cache, initial+i)
+			}
+			f.allocs[initial] = txid
+			return initial
+		}
+
+		previd = id
+	}
+	return 0
+}
+
+// free releases a page and its overflow for a given transaction id.
+// If the page is already free then a panic will occur.
+func (f *freelist) free(txid txid, p *page) {
+	if p.id <= 1 {
+		panic(fmt.Sprintf("cannot free page 0 or 1: %d", p.id))
+	}
+
+	// Free page and all its overflow pages.
+	txp := f.pending[txid]
+	if txp == nil {
+		txp = &txPending{}
+		f.pending[txid] = txp
+	}
+	allocTxid, ok := f.allocs[p.id]
+	if ok {
+		delete(f.allocs, p.id)
+	} else if (p.flags & freelistPageFlag) != 0 {
+		// Freelist is always allocated by prior tx.
+		allocTxid = txid - 1
+	}
+
+	for id := p.id; id <= p.id+pgid(p.overflow); id++ {
+		// Verify that page is not already free.
+		if f.cache[id] {
+			panic(fmt.Sprintf("page %d already freed", id))
+		}
+		// Add to the freelist and cache.
+		txp.ids = append(txp.ids, id)
+		txp.alloctx = append(txp.alloctx, allocTxid)
+		f.cache[id] = true
+	}
+}
+
+// release moves all page ids for a transaction id (or older) to the freelist.
+func (f *freelist) release(txid txid) {
+	m := make(pgids, 0)
+	for tid, txp := range f.pending {
+		if tid <= txid {
+			// Move transaction's pending pages to the available freelist.
+			// Don't remove from the cache since the page is still free.
+			m = append(m, txp.ids...)
+			delete(f.pending, tid)
+		}
+	}
+	f.mergeSpans(m)
+}
+
+// releaseRange moves pending pages allocated within an extent [begin,end] to the free list.
+func (f *freelist) releaseRange(begin, end txid) {
+	if begin > end {
+		return
+	}
+	var m pgids
+	for tid, txp := range f.pending {
+		if tid < begin || tid > end {
+			continue
+		}
+		// Don't recompute freed pages if ranges haven't updated.
+		if txp.lastReleaseBegin == begin {
+			continue
+		}
+		for i := 0; i < len(txp.ids); i++ {
+			if atx := txp.alloctx[i]; atx < begin || atx > end {
+				continue
+			}
+			m = append(m, txp.ids[i])
+			txp.ids[i] = txp.ids[len(txp.ids)-1]
+			txp.ids = txp.ids[:len(txp.ids)-1]
+			txp.alloctx[i] = txp.alloctx[len(txp.alloctx)-1]
+			txp.alloctx = txp.alloctx[:len(txp.alloctx)-1]
+			i--
+		}
+		txp.lastReleaseBegin = begin
+		if len(txp.ids) == 0 {
+			delete(f.pending, tid)
+		}
+	}
+	f.mergeSpans(m)
+}
+
+// rollback removes the pages from a given pending tx.
+func (f *freelist) rollback(txid txid) {
+	// Remove page ids from cache.
+	txp := f.pending[txid]
+	if txp == nil {
+		return
+	}
+	var m pgids
+	for i, pgid := range txp.ids {
+		delete(f.cache, pgid)
+		tx := txp.alloctx[i]
+		if tx == 0 {
+			continue
+		}
+		if tx != txid {
+			// Pending free aborted; restore page back to alloc list.
+			f.allocs[pgid] = tx
+		} else {
+			// Freed page was allocated by this txn; OK to throw away.
+			m = append(m, pgid)
+		}
+	}
+	// Remove pages from pending list and mark as free if allocated by txid.
+	delete(f.pending, txid)
+	f.mergeSpans(m)
+}
+
+// freed returns whether a given page is in the free list.
+func (f *freelist) freed(pgid pgid) bool {
+	return f.cache[pgid]
+}
+
+// read initializes the freelist from a freelist page.
+func (f *freelist) read(p *page) {
+	if (p.flags & freelistPageFlag) == 0 {
+		panic(fmt.Sprintf("invalid freelist page: %d, page type is %s", p.id, p.typ()))
+	}
+	// If the page.count is at the max uint16 value (64k) then it's considered
+	// an overflow and the size of the freelist is stored as the first element.
+	idx, count := 0, int(p.count)
+	if count == 0xFFFF {
+		idx = 1
+		count = int(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[0])
+	}
+
+	// Copy the list of page ids from the freelist.
+	if count == 0 {
+		f.ids = nil
+	} else {
+		ids := ((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[idx : idx+count]
+
+		// copy the ids, so we don't modify on the freelist page directly
+		idsCopy := make([]pgid, count)
+		copy(idsCopy, ids)
+		// Make sure they're sorted.
+		sort.Sort(pgids(idsCopy))
+
+		f.readIDs(idsCopy)
+	}
+}
+
+// arrayReadIDs initializes the freelist from a given list of ids.
+func (f *freelist) arrayReadIDs(ids []pgid) {
+	f.ids = ids
+	f.reindex()
+}
+
+func (f *freelist) arrayGetFreePageIDs() []pgid {
+	return f.ids
+}
+
+// write writes the page ids onto a freelist page. All free and pending ids are
+// saved to disk since in the event of a program crash, all pending ids will
+// become free.
+func (f *freelist) write(p *page) error {
+	// Combine the old free pgids and pgids waiting on an open transaction.
+
+	// Update the header flag.
+	p.flags |= freelistPageFlag
+
+	// The page.count can only hold up to 64k elements so if we overflow that
+	// number then we handle it by putting the size in the first element.
+	lenids := f.count()
+	if lenids == 0 {
+		p.count = uint16(lenids)
+	} else if lenids < 0xFFFF {
+		p.count = uint16(lenids)
+		f.copyall(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[:])
+	} else {
+		p.count = 0xFFFF
+		((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[0] = pgid(lenids)
+		f.copyall(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[1:])
+	}
+
+	return nil
+}
+
+// reload reads the freelist from a page and filters out pending items.
+func (f *freelist) reload(p *page) {
+	f.read(p)
+
+	// Build a cache of only pending pages.
+	pcache := make(map[pgid]bool)
+	for _, txp := range f.pending {
+		for _, pendingID := range txp.ids {
+			pcache[pendingID] = true
+		}
+	}
+
+	// Check each page in the freelist and build a new available freelist
+	// with any pages not in the pending lists.
+	var a []pgid
+	for _, id := range f.getFreePageIDs() {
+		if !pcache[id] {
+			a = append(a, id)
+		}
+	}
+
+	f.readIDs(a)
+}
+
+// noSyncReload reads the freelist from pgids and filters out pending items.
+func (f *freelist) noSyncReload(pgids []pgid) {
+	// Build a cache of only pending pages.
+	pcache := make(map[pgid]bool)
+	for _, txp := range f.pending {
+		for _, pendingID := range txp.ids {
+			pcache[pendingID] = true
+		}
+	}
+
+	// Check each page in the freelist and build a new available freelist
+	// with any pages not in the pending lists.
+	var a []pgid
+	for _, id := range pgids {
+		if !pcache[id] {
+			a = append(a, id)
+		}
+	}
+
+	f.readIDs(a)
+}
+
+// reindex rebuilds the free cache based on available and pending free lists.
+func (f *freelist) reindex() {
+	ids := f.getFreePageIDs()
+	f.cache = make(map[pgid]bool, len(ids))
+	for _, id := range ids {
+		f.cache[id] = true
+	}
+	for _, txp := range f.pending {
+		for _, pendingID := range txp.ids {
+			f.cache[pendingID] = true
+		}
+	}
+}
+
+// arrayMergeSpans try to merge list of pages(represented by pgids) with existing spans but using array
+func (f *freelist) arrayMergeSpans(ids pgids) {
+	sort.Sort(ids)
+	f.ids = pgids(f.ids).merge(ids)
+}
diff --git a/vendor/go.etcd.io/bbolt/freelist_hmap.go b/vendor/go.etcd.io/bbolt/freelist_hmap.go
new file mode 100644
index 0000000..6a03a6c
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/freelist_hmap.go
@@ -0,0 +1,178 @@
+package bbolt
+
+import "sort"
+
+// hashmapFreeCount returns count of free pages(hashmap version)
+func (f *freelist) hashmapFreeCount() int {
+	// use the forwardmap to get the total count
+	count := 0
+	for _, size := range f.forwardMap {
+		count += int(size)
+	}
+	return count
+}
+
+// hashmapAllocate serves the same purpose as arrayAllocate, but use hashmap as backend
+func (f *freelist) hashmapAllocate(txid txid, n int) pgid {
+	if n == 0 {
+		return 0
+	}
+
+	// if we have a exact size match just return short path
+	if bm, ok := f.freemaps[uint64(n)]; ok {
+		for pid := range bm {
+			// remove the span
+			f.delSpan(pid, uint64(n))
+
+			f.allocs[pid] = txid
+
+			for i := pgid(0); i < pgid(n); i++ {
+				delete(f.cache, pid+pgid(i))
+			}
+			return pid
+		}
+	}
+
+	// lookup the map to find larger span
+	for size, bm := range f.freemaps {
+		if size < uint64(n) {
+			continue
+		}
+
+		for pid := range bm {
+			// remove the initial
+			f.delSpan(pid, uint64(size))
+
+			f.allocs[pid] = txid
+
+			remain := size - uint64(n)
+
+			// add remain span
+			f.addSpan(pid+pgid(n), remain)
+
+			for i := pgid(0); i < pgid(n); i++ {
+				delete(f.cache, pid+pgid(i))
+			}
+			return pid
+		}
+	}
+
+	return 0
+}
+
+// hashmapReadIDs reads pgids as input an initial the freelist(hashmap version)
+func (f *freelist) hashmapReadIDs(pgids []pgid) {
+	f.init(pgids)
+
+	// Rebuild the page cache.
+	f.reindex()
+}
+
+// hashmapGetFreePageIDs returns the sorted free page ids
+func (f *freelist) hashmapGetFreePageIDs() []pgid {
+	count := f.free_count()
+	if count == 0 {
+		return nil
+	}
+
+	m := make([]pgid, 0, count)
+	for start, size := range f.forwardMap {
+		for i := 0; i < int(size); i++ {
+			m = append(m, start+pgid(i))
+		}
+	}
+	sort.Sort(pgids(m))
+
+	return m
+}
+
+// hashmapMergeSpans try to merge list of pages(represented by pgids) with existing spans
+func (f *freelist) hashmapMergeSpans(ids pgids) {
+	for _, id := range ids {
+		// try to see if we can merge and update
+		f.mergeWithExistingSpan(id)
+	}
+}
+
+// mergeWithExistingSpan merges pid to the existing free spans, try to merge it backward and forward
+func (f *freelist) mergeWithExistingSpan(pid pgid) {
+	prev := pid - 1
+	next := pid + 1
+
+	preSize, mergeWithPrev := f.backwardMap[prev]
+	nextSize, mergeWithNext := f.forwardMap[next]
+	newStart := pid
+	newSize := uint64(1)
+
+	if mergeWithPrev {
+		//merge with previous span
+		start := prev + 1 - pgid(preSize)
+		f.delSpan(start, preSize)
+
+		newStart -= pgid(preSize)
+		newSize += preSize
+	}
+
+	if mergeWithNext {
+		// merge with next span
+		f.delSpan(next, nextSize)
+		newSize += nextSize
+	}
+
+	f.addSpan(newStart, newSize)
+}
+
+func (f *freelist) addSpan(start pgid, size uint64) {
+	f.backwardMap[start-1+pgid(size)] = size
+	f.forwardMap[start] = size
+	if _, ok := f.freemaps[size]; !ok {
+		f.freemaps[size] = make(map[pgid]struct{})
+	}
+
+	f.freemaps[size][start] = struct{}{}
+}
+
+func (f *freelist) delSpan(start pgid, size uint64) {
+	delete(f.forwardMap, start)
+	delete(f.backwardMap, start+pgid(size-1))
+	delete(f.freemaps[size], start)
+	if len(f.freemaps[size]) == 0 {
+		delete(f.freemaps, size)
+	}
+}
+
+// initial from pgids using when use hashmap version
+// pgids must be sorted
+func (f *freelist) init(pgids []pgid) {
+	if len(pgids) == 0 {
+		return
+	}
+
+	size := uint64(1)
+	start := pgids[0]
+
+	if !sort.SliceIsSorted([]pgid(pgids), func(i, j int) bool { return pgids[i] < pgids[j] }) {
+		panic("pgids not sorted")
+	}
+
+	f.freemaps = make(map[uint64]pidSet)
+	f.forwardMap = make(map[pgid]uint64)
+	f.backwardMap = make(map[pgid]uint64)
+
+	for i := 1; i < len(pgids); i++ {
+		// continuous page
+		if pgids[i] == pgids[i-1]+1 {
+			size++
+		} else {
+			f.addSpan(start, size)
+
+			size = 1
+			start = pgids[i]
+		}
+	}
+
+	// init the tail
+	if size != 0 && start != 0 {
+		f.addSpan(start, size)
+	}
+}
diff --git a/vendor/go.etcd.io/bbolt/node.go b/vendor/go.etcd.io/bbolt/node.go
new file mode 100644
index 0000000..6c3fa55
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/node.go
@@ -0,0 +1,604 @@
+package bbolt
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"unsafe"
+)
+
+// node represents an in-memory, deserialized page.
+type node struct {
+	bucket     *Bucket
+	isLeaf     bool
+	unbalanced bool
+	spilled    bool
+	key        []byte
+	pgid       pgid
+	parent     *node
+	children   nodes
+	inodes     inodes
+}
+
+// root returns the top-level node this node is attached to.
+func (n *node) root() *node {
+	if n.parent == nil {
+		return n
+	}
+	return n.parent.root()
+}
+
+// minKeys returns the minimum number of inodes this node should have.
+func (n *node) minKeys() int {
+	if n.isLeaf {
+		return 1
+	}
+	return 2
+}
+
+// size returns the size of the node after serialization.
+func (n *node) size() int {
+	sz, elsz := pageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + len(item.key) + len(item.value)
+	}
+	return sz
+}
+
+// sizeLessThan returns true if the node is less than a given size.
+// This is an optimization to avoid calculating a large node when we only need
+// to know if it fits inside a certain page size.
+func (n *node) sizeLessThan(v int) bool {
+	sz, elsz := pageHeaderSize, n.pageElementSize()
+	for i := 0; i < len(n.inodes); i++ {
+		item := &n.inodes[i]
+		sz += elsz + len(item.key) + len(item.value)
+		if sz >= v {
+			return false
+		}
+	}
+	return true
+}
+
+// pageElementSize returns the size of each page element based on the type of node.
+func (n *node) pageElementSize() int {
+	if n.isLeaf {
+		return leafPageElementSize
+	}
+	return branchPageElementSize
+}
+
+// childAt returns the child node at a given index.
+func (n *node) childAt(index int) *node {
+	if n.isLeaf {
+		panic(fmt.Sprintf("invalid childAt(%d) on a leaf node", index))
+	}
+	return n.bucket.node(n.inodes[index].pgid, n)
+}
+
+// childIndex returns the index of a given child node.
+func (n *node) childIndex(child *node) int {
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, child.key) != -1 })
+	return index
+}
+
+// numChildren returns the number of children.
+func (n *node) numChildren() int {
+	return len(n.inodes)
+}
+
+// nextSibling returns the next node with the same parent.
+func (n *node) nextSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index >= n.parent.numChildren()-1 {
+		return nil
+	}
+	return n.parent.childAt(index + 1)
+}
+
+// prevSibling returns the previous node with the same parent.
+func (n *node) prevSibling() *node {
+	if n.parent == nil {
+		return nil
+	}
+	index := n.parent.childIndex(n)
+	if index == 0 {
+		return nil
+	}
+	return n.parent.childAt(index - 1)
+}
+
+// put inserts a key/value.
+func (n *node) put(oldKey, newKey, value []byte, pgid pgid, flags uint32) {
+	if pgid >= n.bucket.tx.meta.pgid {
+		panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", pgid, n.bucket.tx.meta.pgid))
+	} else if len(oldKey) <= 0 {
+		panic("put: zero-length old key")
+	} else if len(newKey) <= 0 {
+		panic("put: zero-length new key")
+	}
+
+	// Find insertion index.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, oldKey) != -1 })
+
+	// Add capacity and shift nodes if we don't have an exact match and need to insert.
+	exact := (len(n.inodes) > 0 && index < len(n.inodes) && bytes.Equal(n.inodes[index].key, oldKey))
+	if !exact {
+		n.inodes = append(n.inodes, inode{})
+		copy(n.inodes[index+1:], n.inodes[index:])
+	}
+
+	inode := &n.inodes[index]
+	inode.flags = flags
+	inode.key = newKey
+	inode.value = value
+	inode.pgid = pgid
+	_assert(len(inode.key) > 0, "put: zero-length inode key")
+}
+
+// del removes a key from the node.
+func (n *node) del(key []byte) {
+	// Find index of key.
+	index := sort.Search(len(n.inodes), func(i int) bool { return bytes.Compare(n.inodes[i].key, key) != -1 })
+
+	// Exit if the key isn't found.
+	if index >= len(n.inodes) || !bytes.Equal(n.inodes[index].key, key) {
+		return
+	}
+
+	// Delete inode from the node.
+	n.inodes = append(n.inodes[:index], n.inodes[index+1:]...)
+
+	// Mark the node as needing rebalancing.
+	n.unbalanced = true
+}
+
+// read initializes the node from a page.
+func (n *node) read(p *page) {
+	n.pgid = p.id
+	n.isLeaf = ((p.flags & leafPageFlag) != 0)
+	n.inodes = make(inodes, int(p.count))
+
+	for i := 0; i < int(p.count); i++ {
+		inode := &n.inodes[i]
+		if n.isLeaf {
+			elem := p.leafPageElement(uint16(i))
+			inode.flags = elem.flags
+			inode.key = elem.key()
+			inode.value = elem.value()
+		} else {
+			elem := p.branchPageElement(uint16(i))
+			inode.pgid = elem.pgid
+			inode.key = elem.key()
+		}
+		_assert(len(inode.key) > 0, "read: zero-length inode key")
+	}
+
+	// Save first key so we can find the node in the parent when we spill.
+	if len(n.inodes) > 0 {
+		n.key = n.inodes[0].key
+		_assert(len(n.key) > 0, "read: zero-length node key")
+	} else {
+		n.key = nil
+	}
+}
+
+// write writes the items onto one or more pages.
+func (n *node) write(p *page) {
+	// Initialize page.
+	if n.isLeaf {
+		p.flags |= leafPageFlag
+	} else {
+		p.flags |= branchPageFlag
+	}
+
+	if len(n.inodes) >= 0xFFFF {
+		panic(fmt.Sprintf("inode overflow: %d (pgid=%d)", len(n.inodes), p.id))
+	}
+	p.count = uint16(len(n.inodes))
+
+	// Stop here if there are no items to write.
+	if p.count == 0 {
+		return
+	}
+
+	// Loop over each item and write it to the page.
+	b := (*[maxAllocSize]byte)(unsafe.Pointer(&p.ptr))[n.pageElementSize()*len(n.inodes):]
+	for i, item := range n.inodes {
+		_assert(len(item.key) > 0, "write: zero-length inode key")
+
+		// Write the page element.
+		if n.isLeaf {
+			elem := p.leafPageElement(uint16(i))
+			elem.pos = uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem)))
+			elem.flags = item.flags
+			elem.ksize = uint32(len(item.key))
+			elem.vsize = uint32(len(item.value))
+		} else {
+			elem := p.branchPageElement(uint16(i))
+			elem.pos = uint32(uintptr(unsafe.Pointer(&b[0])) - uintptr(unsafe.Pointer(elem)))
+			elem.ksize = uint32(len(item.key))
+			elem.pgid = item.pgid
+			_assert(elem.pgid != p.id, "write: circular dependency occurred")
+		}
+
+		// If the length of key+value is larger than the max allocation size
+		// then we need to reallocate the byte array pointer.
+		//
+		// See: https://github.com/boltdb/bolt/pull/335
+		klen, vlen := len(item.key), len(item.value)
+		if len(b) < klen+vlen {
+			b = (*[maxAllocSize]byte)(unsafe.Pointer(&b[0]))[:]
+		}
+
+		// Write data for the element to the end of the page.
+		copy(b[0:], item.key)
+		b = b[klen:]
+		copy(b[0:], item.value)
+		b = b[vlen:]
+	}
+
+	// DEBUG ONLY: n.dump()
+}
+
+// split breaks up a node into multiple smaller nodes, if appropriate.
+// This should only be called from the spill() function.
+func (n *node) split(pageSize int) []*node {
+	var nodes []*node
+
+	node := n
+	for {
+		// Split node into two.
+		a, b := node.splitTwo(pageSize)
+		nodes = append(nodes, a)
+
+		// If we can't split then exit the loop.
+		if b == nil {
+			break
+		}
+
+		// Set node to b so it gets split on the next iteration.
+		node = b
+	}
+
+	return nodes
+}
+
+// splitTwo breaks up a node into two smaller nodes, if appropriate.
+// This should only be called from the split() function.
+func (n *node) splitTwo(pageSize int) (*node, *node) {
+	// Ignore the split if the page doesn't have at least enough nodes for
+	// two pages or if the nodes can fit in a single page.
+	if len(n.inodes) <= (minKeysPerPage*2) || n.sizeLessThan(pageSize) {
+		return n, nil
+	}
+
+	// Determine the threshold before starting a new node.
+	var fillPercent = n.bucket.FillPercent
+	if fillPercent < minFillPercent {
+		fillPercent = minFillPercent
+	} else if fillPercent > maxFillPercent {
+		fillPercent = maxFillPercent
+	}
+	threshold := int(float64(pageSize) * fillPercent)
+
+	// Determine split position and sizes of the two pages.
+	splitIndex, _ := n.splitIndex(threshold)
+
+	// Split node into two separate nodes.
+	// If there's no parent then we'll need to create one.
+	if n.parent == nil {
+		n.parent = &node{bucket: n.bucket, children: []*node{n}}
+	}
+
+	// Create a new node and add it to the parent.
+	next := &node{bucket: n.bucket, isLeaf: n.isLeaf, parent: n.parent}
+	n.parent.children = append(n.parent.children, next)
+
+	// Split inodes across two nodes.
+	next.inodes = n.inodes[splitIndex:]
+	n.inodes = n.inodes[:splitIndex]
+
+	// Update the statistics.
+	n.bucket.tx.stats.Split++
+
+	return n, next
+}
+
+// splitIndex finds the position where a page will fill a given threshold.
+// It returns the index as well as the size of the first page.
+// This is only be called from split().
+func (n *node) splitIndex(threshold int) (index, sz int) {
+	sz = pageHeaderSize
+
+	// Loop until we only have the minimum number of keys required for the second page.
+	for i := 0; i < len(n.inodes)-minKeysPerPage; i++ {
+		index = i
+		inode := n.inodes[i]
+		elsize := n.pageElementSize() + len(inode.key) + len(inode.value)
+
+		// If we have at least the minimum number of keys and adding another
+		// node would put us over the threshold then exit and return.
+		if i >= minKeysPerPage && sz+elsize > threshold {
+			break
+		}
+
+		// Add the element size to the total size.
+		sz += elsize
+	}
+
+	return
+}
+
+// spill writes the nodes to dirty pages and splits nodes as it goes.
+// Returns an error if dirty pages cannot be allocated.
+func (n *node) spill() error {
+	var tx = n.bucket.tx
+	if n.spilled {
+		return nil
+	}
+
+	// Spill child nodes first. Child nodes can materialize sibling nodes in
+	// the case of split-merge so we cannot use a range loop. We have to check
+	// the children size on every loop iteration.
+	sort.Sort(n.children)
+	for i := 0; i < len(n.children); i++ {
+		if err := n.children[i].spill(); err != nil {
+			return err
+		}
+	}
+
+	// We no longer need the child list because it's only used for spill tracking.
+	n.children = nil
+
+	// Split nodes into appropriate sizes. The first node will always be n.
+	var nodes = n.split(tx.db.pageSize)
+	for _, node := range nodes {
+		// Add node's page to the freelist if it's not new.
+		if node.pgid > 0 {
+			tx.db.freelist.free(tx.meta.txid, tx.page(node.pgid))
+			node.pgid = 0
+		}
+
+		// Allocate contiguous space for the node.
+		p, err := tx.allocate((node.size() + tx.db.pageSize - 1) / tx.db.pageSize)
+		if err != nil {
+			return err
+		}
+
+		// Write the node.
+		if p.id >= tx.meta.pgid {
+			panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", p.id, tx.meta.pgid))
+		}
+		node.pgid = p.id
+		node.write(p)
+		node.spilled = true
+
+		// Insert into parent inodes.
+		if node.parent != nil {
+			var key = node.key
+			if key == nil {
+				key = node.inodes[0].key
+			}
+
+			node.parent.put(key, node.inodes[0].key, nil, node.pgid, 0)
+			node.key = node.inodes[0].key
+			_assert(len(node.key) > 0, "spill: zero-length node key")
+		}
+
+		// Update the statistics.
+		tx.stats.Spill++
+	}
+
+	// If the root node split and created a new root then we need to spill that
+	// as well. We'll clear out the children to make sure it doesn't try to respill.
+	if n.parent != nil && n.parent.pgid == 0 {
+		n.children = nil
+		return n.parent.spill()
+	}
+
+	return nil
+}
+
+// rebalance attempts to combine the node with sibling nodes if the node fill
+// size is below a threshold or if there are not enough keys.
+func (n *node) rebalance() {
+	if !n.unbalanced {
+		return
+	}
+	n.unbalanced = false
+
+	// Update statistics.
+	n.bucket.tx.stats.Rebalance++
+
+	// Ignore if node is above threshold (25%) and has enough keys.
+	var threshold = n.bucket.tx.db.pageSize / 4
+	if n.size() > threshold && len(n.inodes) > n.minKeys() {
+		return
+	}
+
+	// Root node has special handling.
+	if n.parent == nil {
+		// If root node is a branch and only has one node then collapse it.
+		if !n.isLeaf && len(n.inodes) == 1 {
+			// Move root's child up.
+			child := n.bucket.node(n.inodes[0].pgid, n)
+			n.isLeaf = child.isLeaf
+			n.inodes = child.inodes[:]
+			n.children = child.children
+
+			// Reparent all child nodes being moved.
+			for _, inode := range n.inodes {
+				if child, ok := n.bucket.nodes[inode.pgid]; ok {
+					child.parent = n
+				}
+			}
+
+			// Remove old child.
+			child.parent = nil
+			delete(n.bucket.nodes, child.pgid)
+			child.free()
+		}
+
+		return
+	}
+
+	// If node has no keys then just remove it.
+	if n.numChildren() == 0 {
+		n.parent.del(n.key)
+		n.parent.removeChild(n)
+		delete(n.bucket.nodes, n.pgid)
+		n.free()
+		n.parent.rebalance()
+		return
+	}
+
+	_assert(n.parent.numChildren() > 1, "parent must have at least 2 children")
+
+	// Destination node is right sibling if idx == 0, otherwise left sibling.
+	var target *node
+	var useNextSibling = (n.parent.childIndex(n) == 0)
+	if useNextSibling {
+		target = n.nextSibling()
+	} else {
+		target = n.prevSibling()
+	}
+
+	// If both this node and the target node are too small then merge them.
+	if useNextSibling {
+		// Reparent all child nodes being moved.
+		for _, inode := range target.inodes {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
+				child.parent.removeChild(child)
+				child.parent = n
+				child.parent.children = append(child.parent.children, child)
+			}
+		}
+
+		// Copy over inodes from target and remove target.
+		n.inodes = append(n.inodes, target.inodes...)
+		n.parent.del(target.key)
+		n.parent.removeChild(target)
+		delete(n.bucket.nodes, target.pgid)
+		target.free()
+	} else {
+		// Reparent all child nodes being moved.
+		for _, inode := range n.inodes {
+			if child, ok := n.bucket.nodes[inode.pgid]; ok {
+				child.parent.removeChild(child)
+				child.parent = target
+				child.parent.children = append(child.parent.children, child)
+			}
+		}
+
+		// Copy over inodes to target and remove node.
+		target.inodes = append(target.inodes, n.inodes...)
+		n.parent.del(n.key)
+		n.parent.removeChild(n)
+		delete(n.bucket.nodes, n.pgid)
+		n.free()
+	}
+
+	// Either this node or the target node was deleted from the parent so rebalance it.
+	n.parent.rebalance()
+}
+
+// removes a node from the list of in-memory children.
+// This does not affect the inodes.
+func (n *node) removeChild(target *node) {
+	for i, child := range n.children {
+		if child == target {
+			n.children = append(n.children[:i], n.children[i+1:]...)
+			return
+		}
+	}
+}
+
+// dereference causes the node to copy all its inode key/value references to heap memory.
+// This is required when the mmap is reallocated so inodes are not pointing to stale data.
+func (n *node) dereference() {
+	if n.key != nil {
+		key := make([]byte, len(n.key))
+		copy(key, n.key)
+		n.key = key
+		_assert(n.pgid == 0 || len(n.key) > 0, "dereference: zero-length node key on existing node")
+	}
+
+	for i := range n.inodes {
+		inode := &n.inodes[i]
+
+		key := make([]byte, len(inode.key))
+		copy(key, inode.key)
+		inode.key = key
+		_assert(len(inode.key) > 0, "dereference: zero-length inode key")
+
+		value := make([]byte, len(inode.value))
+		copy(value, inode.value)
+		inode.value = value
+	}
+
+	// Recursively dereference children.
+	for _, child := range n.children {
+		child.dereference()
+	}
+
+	// Update statistics.
+	n.bucket.tx.stats.NodeDeref++
+}
+
+// free adds the node's underlying page to the freelist.
+func (n *node) free() {
+	if n.pgid != 0 {
+		n.bucket.tx.db.freelist.free(n.bucket.tx.meta.txid, n.bucket.tx.page(n.pgid))
+		n.pgid = 0
+	}
+}
+
+// dump writes the contents of the node to STDERR for debugging purposes.
+/*
+func (n *node) dump() {
+	// Write node header.
+	var typ = "branch"
+	if n.isLeaf {
+		typ = "leaf"
+	}
+	warnf("[NODE %d {type=%s count=%d}]", n.pgid, typ, len(n.inodes))
+
+	// Write out abbreviated version of each item.
+	for _, item := range n.inodes {
+		if n.isLeaf {
+			if item.flags&bucketLeafFlag != 0 {
+				bucket := (*bucket)(unsafe.Pointer(&item.value[0]))
+				warnf("+L %08x -> (bucket root=%d)", trunc(item.key, 4), bucket.root)
+			} else {
+				warnf("+L %08x -> %08x", trunc(item.key, 4), trunc(item.value, 4))
+			}
+		} else {
+			warnf("+B %08x -> pgid=%d", trunc(item.key, 4), item.pgid)
+		}
+	}
+	warn("")
+}
+*/
+
+type nodes []*node
+
+func (s nodes) Len() int           { return len(s) }
+func (s nodes) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s nodes) Less(i, j int) bool { return bytes.Compare(s[i].inodes[0].key, s[j].inodes[0].key) == -1 }
+
+// inode represents an internal node inside of a node.
+// It can be used to point to elements in a page or point
+// to an element which hasn't been added to a page yet.
+type inode struct {
+	flags uint32
+	pgid  pgid
+	key   []byte
+	value []byte
+}
+
+type inodes []inode
diff --git a/vendor/go.etcd.io/bbolt/page.go b/vendor/go.etcd.io/bbolt/page.go
new file mode 100644
index 0000000..bca9615
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/page.go
@@ -0,0 +1,197 @@
+package bbolt
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"unsafe"
+)
+
+const pageHeaderSize = int(unsafe.Offsetof(((*page)(nil)).ptr))
+
+const minKeysPerPage = 2
+
+const branchPageElementSize = int(unsafe.Sizeof(branchPageElement{}))
+const leafPageElementSize = int(unsafe.Sizeof(leafPageElement{}))
+
+const (
+	branchPageFlag   = 0x01
+	leafPageFlag     = 0x02
+	metaPageFlag     = 0x04
+	freelistPageFlag = 0x10
+)
+
+const (
+	bucketLeafFlag = 0x01
+)
+
+type pgid uint64
+
+type page struct {
+	id       pgid
+	flags    uint16
+	count    uint16
+	overflow uint32
+	ptr      uintptr
+}
+
+// typ returns a human readable page type string used for debugging.
+func (p *page) typ() string {
+	if (p.flags & branchPageFlag) != 0 {
+		return "branch"
+	} else if (p.flags & leafPageFlag) != 0 {
+		return "leaf"
+	} else if (p.flags & metaPageFlag) != 0 {
+		return "meta"
+	} else if (p.flags & freelistPageFlag) != 0 {
+		return "freelist"
+	}
+	return fmt.Sprintf("unknown<%02x>", p.flags)
+}
+
+// meta returns a pointer to the metadata section of the page.
+func (p *page) meta() *meta {
+	return (*meta)(unsafe.Pointer(&p.ptr))
+}
+
+// leafPageElement retrieves the leaf node by index
+func (p *page) leafPageElement(index uint16) *leafPageElement {
+	n := &((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[index]
+	return n
+}
+
+// leafPageElements retrieves a list of leaf nodes.
+func (p *page) leafPageElements() []leafPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	return ((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[:]
+}
+
+// branchPageElement retrieves the branch node by index
+func (p *page) branchPageElement(index uint16) *branchPageElement {
+	return &((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[index]
+}
+
+// branchPageElements retrieves a list of branch nodes.
+func (p *page) branchPageElements() []branchPageElement {
+	if p.count == 0 {
+		return nil
+	}
+	return ((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[:]
+}
+
+// dump writes n bytes of the page to STDERR as hex output.
+func (p *page) hexdump(n int) {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:n]
+	fmt.Fprintf(os.Stderr, "%x\n", buf)
+}
+
+type pages []*page
+
+func (s pages) Len() int           { return len(s) }
+func (s pages) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s pages) Less(i, j int) bool { return s[i].id < s[j].id }
+
+// branchPageElement represents a node on a branch page.
+type branchPageElement struct {
+	pos   uint32
+	ksize uint32
+	pgid  pgid
+}
+
+// key returns a byte slice of the node key.
+func (n *branchPageElement) key() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize]
+}
+
+// leafPageElement represents a node on a leaf page.
+type leafPageElement struct {
+	flags uint32
+	pos   uint32
+	ksize uint32
+	vsize uint32
+}
+
+// key returns a byte slice of the node key.
+func (n *leafPageElement) key() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize:n.ksize]
+}
+
+// value returns a byte slice of the node value.
+func (n *leafPageElement) value() []byte {
+	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize:n.vsize]
+}
+
+// PageInfo represents human readable information about a page.
+type PageInfo struct {
+	ID            int
+	Type          string
+	Count         int
+	OverflowCount int
+}
+
+type pgids []pgid
+
+func (s pgids) Len() int           { return len(s) }
+func (s pgids) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s pgids) Less(i, j int) bool { return s[i] < s[j] }
+
+// merge returns the sorted union of a and b.
+func (a pgids) merge(b pgids) pgids {
+	// Return the opposite slice if one is nil.
+	if len(a) == 0 {
+		return b
+	}
+	if len(b) == 0 {
+		return a
+	}
+	merged := make(pgids, len(a)+len(b))
+	mergepgids(merged, a, b)
+	return merged
+}
+
+// mergepgids copies the sorted union of a and b into dst.
+// If dst is too small, it panics.
+func mergepgids(dst, a, b pgids) {
+	if len(dst) < len(a)+len(b) {
+		panic(fmt.Errorf("mergepgids bad len %d < %d + %d", len(dst), len(a), len(b)))
+	}
+	// Copy in the opposite slice if one is nil.
+	if len(a) == 0 {
+		copy(dst, b)
+		return
+	}
+	if len(b) == 0 {
+		copy(dst, a)
+		return
+	}
+
+	// Merged will hold all elements from both lists.
+	merged := dst[:0]
+
+	// Assign lead to the slice with a lower starting value, follow to the higher value.
+	lead, follow := a, b
+	if b[0] < a[0] {
+		lead, follow = b, a
+	}
+
+	// Continue while there are elements in the lead.
+	for len(lead) > 0 {
+		// Merge largest prefix of lead that is ahead of follow[0].
+		n := sort.Search(len(lead), func(i int) bool { return lead[i] > follow[0] })
+		merged = append(merged, lead[:n]...)
+		if n >= len(lead) {
+			break
+		}
+
+		// Swap lead and follow.
+		lead, follow = follow, lead[n:]
+	}
+
+	// Append what's left in follow.
+	_ = append(merged, follow...)
+}
diff --git a/vendor/go.etcd.io/bbolt/tx.go b/vendor/go.etcd.io/bbolt/tx.go
new file mode 100644
index 0000000..2df7688
--- /dev/null
+++ b/vendor/go.etcd.io/bbolt/tx.go
@@ -0,0 +1,726 @@
+package bbolt
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"strings"
+	"time"
+	"unsafe"
+)
+
+// txid represents the internal transaction identifier.
+type txid uint64
+
+// Tx represents a read-only or read/write transaction on the database.
+// Read-only transactions can be used for retrieving values for keys and creating cursors.
+// Read/write transactions can create and remove buckets and create and remove keys.
+//
+// IMPORTANT: You must commit or rollback transactions when you are done with
+// them. Pages can not be reclaimed by the writer until no more transactions
+// are using them. A long running read transaction can cause the database to
+// quickly grow.
+type Tx struct {
+	writable       bool
+	managed        bool
+	db             *DB
+	meta           *meta
+	root           Bucket
+	pages          map[pgid]*page
+	stats          TxStats
+	commitHandlers []func()
+
+	// WriteFlag specifies the flag for write-related methods like WriteTo().
+	// Tx opens the database file with the specified flag to copy the data.
+	//
+	// By default, the flag is unset, which works well for mostly in-memory
+	// workloads. For databases that are much larger than available RAM,
+	// set the flag to syscall.O_DIRECT to avoid trashing the page cache.
+	WriteFlag int
+}
+
+// init initializes the transaction.
+func (tx *Tx) init(db *DB) {
+	tx.db = db
+	tx.pages = nil
+
+	// Copy the meta page since it can be changed by the writer.
+	tx.meta = &meta{}
+	db.meta().copy(tx.meta)
+
+	// Copy over the root bucket.
+	tx.root = newBucket(tx)
+	tx.root.bucket = &bucket{}
+	*tx.root.bucket = tx.meta.root
+
+	// Increment the transaction id and add a page cache for writable transactions.
+	if tx.writable {
+		tx.pages = make(map[pgid]*page)
+		tx.meta.txid += txid(1)
+	}
+}
+
+// ID returns the transaction id.
+func (tx *Tx) ID() int {
+	return int(tx.meta.txid)
+}
+
+// DB returns a reference to the database that created the transaction.
+func (tx *Tx) DB() *DB {
+	return tx.db
+}
+
+// Size returns current database size in bytes as seen by this transaction.
+func (tx *Tx) Size() int64 {
+	return int64(tx.meta.pgid) * int64(tx.db.pageSize)
+}
+
+// Writable returns whether the transaction can perform write operations.
+func (tx *Tx) Writable() bool {
+	return tx.writable
+}
+
+// Cursor creates a cursor associated with the root bucket.
+// All items in the cursor will return a nil value because all root bucket keys point to buckets.
+// The cursor is only valid as long as the transaction is open.
+// Do not use a cursor after the transaction is closed.
+func (tx *Tx) Cursor() *Cursor {
+	return tx.root.Cursor()
+}
+
+// Stats retrieves a copy of the current transaction statistics.
+func (tx *Tx) Stats() TxStats {
+	return tx.stats
+}
+
+// Bucket retrieves a bucket by name.
+// Returns nil if the bucket does not exist.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) Bucket(name []byte) *Bucket {
+	return tx.root.Bucket(name)
+}
+
+// CreateBucket creates a new bucket.
+// Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucket(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucket(name)
+}
+
+// CreateBucketIfNotExists creates a new bucket if it doesn't already exist.
+// Returns an error if the bucket name is blank, or if the bucket name is too long.
+// The bucket instance is only valid for the lifetime of the transaction.
+func (tx *Tx) CreateBucketIfNotExists(name []byte) (*Bucket, error) {
+	return tx.root.CreateBucketIfNotExists(name)
+}
+
+// DeleteBucket deletes a bucket.
+// Returns an error if the bucket cannot be found or if the key represents a non-bucket value.
+func (tx *Tx) DeleteBucket(name []byte) error {
+	return tx.root.DeleteBucket(name)
+}
+
+// ForEach executes a function for each bucket in the root.
+// If the provided function returns an error then the iteration is stopped and
+// the error is returned to the caller.
+func (tx *Tx) ForEach(fn func(name []byte, b *Bucket) error) error {
+	return tx.root.ForEach(func(k, v []byte) error {
+		return fn(k, tx.root.Bucket(k))
+	})
+}
+
+// OnCommit adds a handler function to be executed after the transaction successfully commits.
+func (tx *Tx) OnCommit(fn func()) {
+	tx.commitHandlers = append(tx.commitHandlers, fn)
+}
+
+// Commit writes all changes to disk and updates the meta page.
+// Returns an error if a disk write error occurs, or if Commit is
+// called on a read-only transaction.
+func (tx *Tx) Commit() error {
+	_assert(!tx.managed, "managed tx commit not allowed")
+	if tx.db == nil {
+		return ErrTxClosed
+	} else if !tx.writable {
+		return ErrTxNotWritable
+	}
+
+	// TODO(benbjohnson): Use vectorized I/O to write out dirty pages.
+
+	// Rebalance nodes which have had deletions.
+	var startTime = time.Now()
+	tx.root.rebalance()
+	if tx.stats.Rebalance > 0 {
+		tx.stats.RebalanceTime += time.Since(startTime)
+	}
+
+	// spill data onto dirty pages.
+	startTime = time.Now()
+	if err := tx.root.spill(); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.stats.SpillTime += time.Since(startTime)
+
+	// Free the old root bucket.
+	tx.meta.root.root = tx.root.root
+
+	// Free the old freelist because commit writes out a fresh freelist.
+	if tx.meta.freelist != pgidNoFreelist {
+		tx.db.freelist.free(tx.meta.txid, tx.db.page(tx.meta.freelist))
+	}
+
+	if !tx.db.NoFreelistSync {
+		err := tx.commitFreelist()
+		if err != nil {
+			return err
+		}
+	} else {
+		tx.meta.freelist = pgidNoFreelist
+	}
+
+	// Write dirty pages to disk.
+	startTime = time.Now()
+	if err := tx.write(); err != nil {
+		tx.rollback()
+		return err
+	}
+
+	// If strict mode is enabled then perform a consistency check.
+	// Only the first consistency error is reported in the panic.
+	if tx.db.StrictMode {
+		ch := tx.Check()
+		var errs []string
+		for {
+			err, ok := <-ch
+			if !ok {
+				break
+			}
+			errs = append(errs, err.Error())
+		}
+		if len(errs) > 0 {
+			panic("check fail: " + strings.Join(errs, "\n"))
+		}
+	}
+
+	// Write meta to disk.
+	if err := tx.writeMeta(); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.stats.WriteTime += time.Since(startTime)
+
+	// Finalize the transaction.
+	tx.close()
+
+	// Execute commit handlers now that the locks have been removed.
+	for _, fn := range tx.commitHandlers {
+		fn()
+	}
+
+	return nil
+}
+
+func (tx *Tx) commitFreelist() error {
+	// Allocate new pages for the new free list. This will overestimate
+	// the size of the freelist but not underestimate the size (which would be bad).
+	opgid := tx.meta.pgid
+	p, err := tx.allocate((tx.db.freelist.size() / tx.db.pageSize) + 1)
+	if err != nil {
+		tx.rollback()
+		return err
+	}
+	if err := tx.db.freelist.write(p); err != nil {
+		tx.rollback()
+		return err
+	}
+	tx.meta.freelist = p.id
+	// If the high water mark has moved up then attempt to grow the database.
+	if tx.meta.pgid > opgid {
+		if err := tx.db.grow(int(tx.meta.pgid+1) * tx.db.pageSize); err != nil {
+			tx.rollback()
+			return err
+		}
+	}
+
+	return nil
+}
+
+// Rollback closes the transaction and ignores all previous updates. Read-only
+// transactions must be rolled back and not committed.
+func (tx *Tx) Rollback() error {
+	_assert(!tx.managed, "managed tx rollback not allowed")
+	if tx.db == nil {
+		return ErrTxClosed
+	}
+	tx.nonPhysicalRollback()
+	return nil
+}
+
+// nonPhysicalRollback is called when user calls Rollback directly, in this case we do not need to reload the free pages from disk.
+func (tx *Tx) nonPhysicalRollback() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		tx.db.freelist.rollback(tx.meta.txid)
+	}
+	tx.close()
+}
+
+// rollback needs to reload the free pages from disk in case some system error happens like fsync error.
+func (tx *Tx) rollback() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		tx.db.freelist.rollback(tx.meta.txid)
+		if !tx.db.hasSyncedFreelist() {
+			// Reconstruct free page list by scanning the DB to get the whole free page list.
+			// Note: scaning the whole db is heavy if your db size is large in NoSyncFreeList mode.
+			tx.db.freelist.noSyncReload(tx.db.freepages())
+		} else {
+			// Read free page list from freelist page.
+			tx.db.freelist.reload(tx.db.page(tx.db.meta().freelist))
+		}
+	}
+	tx.close()
+}
+
+func (tx *Tx) close() {
+	if tx.db == nil {
+		return
+	}
+	if tx.writable {
+		// Grab freelist stats.
+		var freelistFreeN = tx.db.freelist.free_count()
+		var freelistPendingN = tx.db.freelist.pending_count()
+		var freelistAlloc = tx.db.freelist.size()
+
+		// Remove transaction ref & writer lock.
+		tx.db.rwtx = nil
+		tx.db.rwlock.Unlock()
+
+		// Merge statistics.
+		tx.db.statlock.Lock()
+		tx.db.stats.FreePageN = freelistFreeN
+		tx.db.stats.PendingPageN = freelistPendingN
+		tx.db.stats.FreeAlloc = (freelistFreeN + freelistPendingN) * tx.db.pageSize
+		tx.db.stats.FreelistInuse = freelistAlloc
+		tx.db.stats.TxStats.add(&tx.stats)
+		tx.db.statlock.Unlock()
+	} else {
+		tx.db.removeTx(tx)
+	}
+
+	// Clear all references.
+	tx.db = nil
+	tx.meta = nil
+	tx.root = Bucket{tx: tx}
+	tx.pages = nil
+}
+
+// Copy writes the entire database to a writer.
+// This function exists for backwards compatibility.
+//
+// Deprecated; Use WriteTo() instead.
+func (tx *Tx) Copy(w io.Writer) error {
+	_, err := tx.WriteTo(w)
+	return err
+}
+
+// WriteTo writes the entire database to a writer.
+// If err == nil then exactly tx.Size() bytes will be written into the writer.
+func (tx *Tx) WriteTo(w io.Writer) (n int64, err error) {
+	// Attempt to open reader with WriteFlag
+	f, err := tx.db.openFile(tx.db.path, os.O_RDONLY|tx.WriteFlag, 0)
+	if err != nil {
+		return 0, err
+	}
+	defer func() {
+		if cerr := f.Close(); err == nil {
+			err = cerr
+		}
+	}()
+
+	// Generate a meta page. We use the same page data for both meta pages.
+	buf := make([]byte, tx.db.pageSize)
+	page := (*page)(unsafe.Pointer(&buf[0]))
+	page.flags = metaPageFlag
+	*page.meta() = *tx.meta
+
+	// Write meta 0.
+	page.id = 0
+	page.meta().checksum = page.meta().sum64()
+	nn, err := w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 0 copy: %s", err)
+	}
+
+	// Write meta 1 with a lower transaction id.
+	page.id = 1
+	page.meta().txid -= 1
+	page.meta().checksum = page.meta().sum64()
+	nn, err = w.Write(buf)
+	n += int64(nn)
+	if err != nil {
+		return n, fmt.Errorf("meta 1 copy: %s", err)
+	}
+
+	// Move past the meta pages in the file.
+	if _, err := f.Seek(int64(tx.db.pageSize*2), io.SeekStart); err != nil {
+		return n, fmt.Errorf("seek: %s", err)
+	}
+
+	// Copy data pages.
+	wn, err := io.CopyN(w, f, tx.Size()-int64(tx.db.pageSize*2))
+	n += wn
+	if err != nil {
+		return n, err
+	}
+
+	return n, nil
+}
+
+// CopyFile copies the entire database to file at the given path.
+// A reader transaction is maintained during the copy so it is safe to continue
+// using the database while a copy is in progress.
+func (tx *Tx) CopyFile(path string, mode os.FileMode) error {
+	f, err := tx.db.openFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
+	if err != nil {
+		return err
+	}
+
+	err = tx.Copy(f)
+	if err != nil {
+		_ = f.Close()
+		return err
+	}
+	return f.Close()
+}
+
+// Check performs several consistency checks on the database for this transaction.
+// An error is returned if any inconsistency is found.
+//
+// It can be safely run concurrently on a writable transaction. However, this
+// incurs a high cost for large databases and databases with a lot of subbuckets
+// because of caching. This overhead can be removed if running on a read-only
+// transaction, however, it is not safe to execute other writer transactions at
+// the same time.
+func (tx *Tx) Check() <-chan error {
+	ch := make(chan error)
+	go tx.check(ch)
+	return ch
+}
+
+func (tx *Tx) check(ch chan error) {
+	// Force loading free list if opened in ReadOnly mode.
+	tx.db.loadFreelist()
+
+	// Check if any pages are double freed.
+	freed := make(map[pgid]bool)
+	all := make([]pgid, tx.db.freelist.count())
+	tx.db.freelist.copyall(all)
+	for _, id := range all {
+		if freed[id] {
+			ch <- fmt.Errorf("page %d: already freed", id)
+		}
+		freed[id] = true
+	}
+
+	// Track every reachable page.
+	reachable := make(map[pgid]*page)
+	reachable[0] = tx.page(0) // meta0
+	reachable[1] = tx.page(1) // meta1
+	if tx.meta.freelist != pgidNoFreelist {
+		for i := uint32(0); i <= tx.page(tx.meta.freelist).overflow; i++ {
+			reachable[tx.meta.freelist+pgid(i)] = tx.page(tx.meta.freelist)
+		}
+	}
+
+	// Recursively check buckets.
+	tx.checkBucket(&tx.root, reachable, freed, ch)
+
+	// Ensure all pages below high water mark are either reachable or freed.
+	for i := pgid(0); i < tx.meta.pgid; i++ {
+		_, isReachable := reachable[i]
+		if !isReachable && !freed[i] {
+			ch <- fmt.Errorf("page %d: unreachable unfreed", int(i))
+		}
+	}
+
+	// Close the channel to signal completion.
+	close(ch)
+}
+
+func (tx *Tx) checkBucket(b *Bucket, reachable map[pgid]*page, freed map[pgid]bool, ch chan error) {
+	// Ignore inline buckets.
+	if b.root == 0 {
+		return
+	}
+
+	// Check every page used by this bucket.
+	b.tx.forEachPage(b.root, 0, func(p *page, _ int) {
+		if p.id > tx.meta.pgid {
+			ch <- fmt.Errorf("page %d: out of bounds: %d", int(p.id), int(b.tx.meta.pgid))
+		}
+
+		// Ensure each page is only referenced once.
+		for i := pgid(0); i <= pgid(p.overflow); i++ {
+			var id = p.id + i
+			if _, ok := reachable[id]; ok {
+				ch <- fmt.Errorf("page %d: multiple references", int(id))
+			}
+			reachable[id] = p
+		}
+
+		// We should only encounter un-freed leaf and branch pages.
+		if freed[p.id] {
+			ch <- fmt.Errorf("page %d: reachable freed", int(p.id))
+		} else if (p.flags&branchPageFlag) == 0 && (p.flags&leafPageFlag) == 0 {
+			ch <- fmt.Errorf("page %d: invalid type: %s", int(p.id), p.typ())
+		}
+	})
+
+	// Check each bucket within this bucket.
+	_ = b.ForEach(func(k, v []byte) error {
+		if child := b.Bucket(k); child != nil {
+			tx.checkBucket(child, reachable, freed, ch)
+		}
+		return nil
+	})
+}
+
+// allocate returns a contiguous block of memory starting at a given page.
+func (tx *Tx) allocate(count int) (*page, error) {
+	p, err := tx.db.allocate(tx.meta.txid, count)
+	if err != nil {
+		return nil, err
+	}
+
+	// Save to our page cache.
+	tx.pages[p.id] = p
+
+	// Update statistics.
+	tx.stats.PageCount += count
+	tx.stats.PageAlloc += count * tx.db.pageSize
+
+	return p, nil
+}
+
+// write writes any dirty pages to disk.
+func (tx *Tx) write() error {
+	// Sort pages by id.
+	pages := make(pages, 0, len(tx.pages))
+	for _, p := range tx.pages {
+		pages = append(pages, p)
+	}
+	// Clear out page cache early.
+	tx.pages = make(map[pgid]*page)
+	sort.Sort(pages)
+
+	// Write pages to disk in order.
+	for _, p := range pages {
+		size := (int(p.overflow) + 1) * tx.db.pageSize
+		offset := int64(p.id) * int64(tx.db.pageSize)
+
+		// Write out page in "max allocation" sized chunks.
+		ptr := (*[maxAllocSize]byte)(unsafe.Pointer(p))
+		for {
+			// Limit our write to our max allocation size.
+			sz := size
+			if sz > maxAllocSize-1 {
+				sz = maxAllocSize - 1
+			}
+
+			// Write chunk to disk.
+			buf := ptr[:sz]
+			if _, err := tx.db.ops.writeAt(buf, offset); err != nil {
+				return err
+			}
+
+			// Update statistics.
+			tx.stats.Write++
+
+			// Exit inner for loop if we've written all the chunks.
+			size -= sz
+			if size == 0 {
+				break
+			}
+
+			// Otherwise move offset forward and move pointer to next chunk.
+			offset += int64(sz)
+			ptr = (*[maxAllocSize]byte)(unsafe.Pointer(&ptr[sz]))
+		}
+	}
+
+	// Ignore file sync if flag is set on DB.
+	if !tx.db.NoSync || IgnoreNoSync {
+		if err := fdatasync(tx.db); err != nil {
+			return err
+		}
+	}
+
+	// Put small pages back to page pool.
+	for _, p := range pages {
+		// Ignore page sizes over 1 page.
+		// These are allocated using make() instead of the page pool.
+		if int(p.overflow) != 0 {
+			continue
+		}
+
+		buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:tx.db.pageSize]
+
+		// See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1
+		for i := range buf {
+			buf[i] = 0
+		}
+		tx.db.pagePool.Put(buf)
+	}
+
+	return nil
+}
+
+// writeMeta writes the meta to the disk.
+func (tx *Tx) writeMeta() error {
+	// Create a temporary buffer for the meta page.
+	buf := make([]byte, tx.db.pageSize)
+	p := tx.db.pageInBuffer(buf, 0)
+	tx.meta.write(p)
+
+	// Write the meta page to file.
+	if _, err := tx.db.ops.writeAt(buf, int64(p.id)*int64(tx.db.pageSize)); err != nil {
+		return err
+	}
+	if !tx.db.NoSync || IgnoreNoSync {
+		if err := fdatasync(tx.db); err != nil {
+			return err
+		}
+	}
+
+	// Update statistics.
+	tx.stats.Write++
+
+	return nil
+}
+
+// page returns a reference to the page with a given id.
+// If page has been written to then a temporary buffered page is returned.
+func (tx *Tx) page(id pgid) *page {
+	// Check the dirty pages first.
+	if tx.pages != nil {
+		if p, ok := tx.pages[id]; ok {
+			return p
+		}
+	}
+
+	// Otherwise return directly from the mmap.
+	return tx.db.page(id)
+}
+
+// forEachPage iterates over every page within a given page and executes a function.
+func (tx *Tx) forEachPage(pgid pgid, depth int, fn func(*page, int)) {
+	p := tx.page(pgid)
+
+	// Execute function.
+	fn(p, depth)
+
+	// Recursively loop over children.
+	if (p.flags & branchPageFlag) != 0 {
+		for i := 0; i < int(p.count); i++ {
+			elem := p.branchPageElement(uint16(i))
+			tx.forEachPage(elem.pgid, depth+1, fn)
+		}
+	}
+}
+
+// Page returns page information for a given page number.
+// This is only safe for concurrent use when used by a writable transaction.
+func (tx *Tx) Page(id int) (*PageInfo, error) {
+	if tx.db == nil {
+		return nil, ErrTxClosed
+	} else if pgid(id) >= tx.meta.pgid {
+		return nil, nil
+	}
+
+	// Build the page info.
+	p := tx.db.page(pgid(id))
+	info := &PageInfo{
+		ID:            id,
+		Count:         int(p.count),
+		OverflowCount: int(p.overflow),
+	}
+
+	// Determine the type (or if it's free).
+	if tx.db.freelist.freed(pgid(id)) {
+		info.Type = "free"
+	} else {
+		info.Type = p.typ()
+	}
+
+	return info, nil
+}
+
+// TxStats represents statistics about the actions performed by the transaction.
+type TxStats struct {
+	// Page statistics.
+	PageCount int // number of page allocations
+	PageAlloc int // total bytes allocated
+
+	// Cursor statistics.
+	CursorCount int // number of cursors created
+
+	// Node statistics
+	NodeCount int // number of node allocations
+	NodeDeref int // number of node dereferences
+
+	// Rebalance statistics.
+	Rebalance     int           // number of node rebalances
+	RebalanceTime time.Duration // total time spent rebalancing
+
+	// Split/Spill statistics.
+	Split     int           // number of nodes split
+	Spill     int           // number of nodes spilled
+	SpillTime time.Duration // total time spent spilling
+
+	// Write statistics.
+	Write     int           // number of writes performed
+	WriteTime time.Duration // total time spent writing to disk
+}
+
+func (s *TxStats) add(other *TxStats) {
+	s.PageCount += other.PageCount
+	s.PageAlloc += other.PageAlloc
+	s.CursorCount += other.CursorCount
+	s.NodeCount += other.NodeCount
+	s.NodeDeref += other.NodeDeref
+	s.Rebalance += other.Rebalance
+	s.RebalanceTime += other.RebalanceTime
+	s.Split += other.Split
+	s.Spill += other.Spill
+	s.SpillTime += other.SpillTime
+	s.Write += other.Write
+	s.WriteTime += other.WriteTime
+}
+
+// Sub calculates and returns the difference between two sets of transaction stats.
+// This is useful when obtaining stats at two different points and time and
+// you need the performance counters that occurred within that time span.
+func (s *TxStats) Sub(other *TxStats) TxStats {
+	var diff TxStats
+	diff.PageCount = s.PageCount - other.PageCount
+	diff.PageAlloc = s.PageAlloc - other.PageAlloc
+	diff.CursorCount = s.CursorCount - other.CursorCount
+	diff.NodeCount = s.NodeCount - other.NodeCount
+	diff.NodeDeref = s.NodeDeref - other.NodeDeref
+	diff.Rebalance = s.Rebalance - other.Rebalance
+	diff.RebalanceTime = s.RebalanceTime - other.RebalanceTime
+	diff.Split = s.Split - other.Split
+	diff.Spill = s.Spill - other.Spill
+	diff.SpillTime = s.SpillTime - other.SpillTime
+	diff.Write = s.Write - other.Write
+	diff.WriteTime = s.WriteTime - other.WriteTime
+	return diff
+}
diff --git a/vendor/go.etcd.io/etcd/auth/doc.go b/vendor/go.etcd.io/etcd/auth/doc.go
new file mode 100644
index 0000000..72741a1
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package auth provides client role authentication for accessing keys in etcd.
+package auth
diff --git a/vendor/go.etcd.io/etcd/auth/jwt.go b/vendor/go.etcd.io/etcd/auth/jwt.go
new file mode 100644
index 0000000..c22ef89
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/jwt.go
@@ -0,0 +1,184 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"errors"
+	"time"
+
+	jwt "github.com/dgrijalva/jwt-go"
+	"go.uber.org/zap"
+)
+
+type tokenJWT struct {
+	lg         *zap.Logger
+	signMethod jwt.SigningMethod
+	key        interface{}
+	ttl        time.Duration
+	verifyOnly bool
+}
+
+func (t *tokenJWT) enable()                         {}
+func (t *tokenJWT) disable()                        {}
+func (t *tokenJWT) invalidateUser(string)           {}
+func (t *tokenJWT) genTokenPrefix() (string, error) { return "", nil }
+
+func (t *tokenJWT) info(ctx context.Context, token string, rev uint64) (*AuthInfo, bool) {
+	// rev isn't used in JWT, it is only used in simple token
+	var (
+		username string
+		revision uint64
+	)
+
+	parsed, err := jwt.Parse(token, func(token *jwt.Token) (interface{}, error) {
+		if token.Method.Alg() != t.signMethod.Alg() {
+			return nil, errors.New("invalid signing method")
+		}
+		switch k := t.key.(type) {
+		case *rsa.PrivateKey:
+			return &k.PublicKey, nil
+		case *ecdsa.PrivateKey:
+			return &k.PublicKey, nil
+		default:
+			return t.key, nil
+		}
+	})
+
+	if err != nil {
+		if t.lg != nil {
+			t.lg.Warn(
+				"failed to parse a JWT token",
+				zap.String("token", token),
+				zap.Error(err),
+			)
+		} else {
+			plog.Warningf("failed to parse jwt token: %s", err)
+		}
+		return nil, false
+	}
+
+	claims, ok := parsed.Claims.(jwt.MapClaims)
+	if !parsed.Valid || !ok {
+		if t.lg != nil {
+			t.lg.Warn("invalid JWT token", zap.String("token", token))
+		} else {
+			plog.Warningf("invalid jwt token: %s", token)
+		}
+		return nil, false
+	}
+
+	username = claims["username"].(string)
+	revision = uint64(claims["revision"].(float64))
+
+	return &AuthInfo{Username: username, Revision: revision}, true
+}
+
+func (t *tokenJWT) assign(ctx context.Context, username string, revision uint64) (string, error) {
+	if t.verifyOnly {
+		return "", ErrVerifyOnly
+	}
+
+	// Future work: let a jwt token include permission information would be useful for
+	// permission checking in proxy side.
+	tk := jwt.NewWithClaims(t.signMethod,
+		jwt.MapClaims{
+			"username": username,
+			"revision": revision,
+			"exp":      time.Now().Add(t.ttl).Unix(),
+		})
+
+	token, err := tk.SignedString(t.key)
+	if err != nil {
+		if t.lg != nil {
+			t.lg.Warn(
+				"failed to sign a JWT token",
+				zap.String("user-name", username),
+				zap.Uint64("revision", revision),
+				zap.Error(err),
+			)
+		} else {
+			plog.Debugf("failed to sign jwt token: %s", err)
+		}
+		return "", err
+	}
+
+	if t.lg != nil {
+		t.lg.Info(
+			"created/assigned a new JWT token",
+			zap.String("user-name", username),
+			zap.Uint64("revision", revision),
+			zap.String("token", token),
+		)
+	} else {
+		plog.Debugf("jwt token: %s", token)
+	}
+	return token, err
+}
+
+func newTokenProviderJWT(lg *zap.Logger, optMap map[string]string) (*tokenJWT, error) {
+	var err error
+	var opts jwtOptions
+	err = opts.ParseWithDefaults(optMap)
+	if err != nil {
+		if lg != nil {
+			lg.Warn("problem loading JWT options", zap.Error(err))
+		} else {
+			plog.Errorf("problem loading JWT options: %s", err)
+		}
+		return nil, ErrInvalidAuthOpts
+	}
+
+	var keys = make([]string, 0, len(optMap))
+	for k := range optMap {
+		if !knownOptions[k] {
+			keys = append(keys, k)
+		}
+	}
+	if len(keys) > 0 {
+		if lg != nil {
+			lg.Warn("unknown JWT options", zap.Strings("keys", keys))
+		} else {
+			plog.Warningf("unknown JWT options: %v", keys)
+		}
+	}
+
+	key, err := opts.Key()
+	if err != nil {
+		return nil, err
+	}
+
+	t := &tokenJWT{
+		lg:         lg,
+		ttl:        opts.TTL,
+		signMethod: opts.SignMethod,
+		key:        key,
+	}
+
+	switch t.signMethod.(type) {
+	case *jwt.SigningMethodECDSA:
+		if _, ok := t.key.(*ecdsa.PublicKey); ok {
+			t.verifyOnly = true
+		}
+	case *jwt.SigningMethodRSA, *jwt.SigningMethodRSAPSS:
+		if _, ok := t.key.(*rsa.PublicKey); ok {
+			t.verifyOnly = true
+		}
+	}
+
+	return t, nil
+}
diff --git a/vendor/go.etcd.io/etcd/auth/nop.go b/vendor/go.etcd.io/etcd/auth/nop.go
new file mode 100644
index 0000000..d437874
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/nop.go
@@ -0,0 +1,35 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"context"
+)
+
+type tokenNop struct{}
+
+func (t *tokenNop) enable()                         {}
+func (t *tokenNop) disable()                        {}
+func (t *tokenNop) invalidateUser(string)           {}
+func (t *tokenNop) genTokenPrefix() (string, error) { return "", nil }
+func (t *tokenNop) info(ctx context.Context, token string, rev uint64) (*AuthInfo, bool) {
+	return nil, false
+}
+func (t *tokenNop) assign(ctx context.Context, username string, revision uint64) (string, error) {
+	return "", ErrAuthFailed
+}
+func newTokenProviderNop() (*tokenNop, error) {
+	return &tokenNop{}, nil
+}
diff --git a/vendor/go.etcd.io/etcd/auth/options.go b/vendor/go.etcd.io/etcd/auth/options.go
new file mode 100644
index 0000000..f40b92d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/options.go
@@ -0,0 +1,192 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"fmt"
+	"io/ioutil"
+	"time"
+
+	jwt "github.com/dgrijalva/jwt-go"
+)
+
+const (
+	optSignMethod = "sign-method"
+	optPublicKey  = "pub-key"
+	optPrivateKey = "priv-key"
+	optTTL        = "ttl"
+)
+
+var knownOptions = map[string]bool{
+	optSignMethod: true,
+	optPublicKey:  true,
+	optPrivateKey: true,
+	optTTL:        true,
+}
+
+var (
+	// DefaultTTL will be used when a 'ttl' is not specified
+	DefaultTTL = 5 * time.Minute
+)
+
+type jwtOptions struct {
+	SignMethod jwt.SigningMethod
+	PublicKey  []byte
+	PrivateKey []byte
+	TTL        time.Duration
+}
+
+// ParseWithDefaults will load options from the specified map or set defaults where appropriate
+func (opts *jwtOptions) ParseWithDefaults(optMap map[string]string) error {
+	if opts.TTL == 0 && optMap[optTTL] == "" {
+		opts.TTL = DefaultTTL
+	}
+
+	return opts.Parse(optMap)
+}
+
+// Parse will load options from the specified map
+func (opts *jwtOptions) Parse(optMap map[string]string) error {
+	var err error
+	if ttl := optMap[optTTL]; ttl != "" {
+		opts.TTL, err = time.ParseDuration(ttl)
+		if err != nil {
+			return err
+		}
+	}
+
+	if file := optMap[optPublicKey]; file != "" {
+		opts.PublicKey, err = ioutil.ReadFile(file)
+		if err != nil {
+			return err
+		}
+	}
+
+	if file := optMap[optPrivateKey]; file != "" {
+		opts.PrivateKey, err = ioutil.ReadFile(file)
+		if err != nil {
+			return err
+		}
+	}
+
+	// signing method is a required field
+	method := optMap[optSignMethod]
+	opts.SignMethod = jwt.GetSigningMethod(method)
+	if opts.SignMethod == nil {
+		return ErrInvalidAuthMethod
+	}
+
+	return nil
+}
+
+// Key will parse and return the appropriately typed key for the selected signature method
+func (opts *jwtOptions) Key() (interface{}, error) {
+	switch opts.SignMethod.(type) {
+	case *jwt.SigningMethodRSA, *jwt.SigningMethodRSAPSS:
+		return opts.rsaKey()
+	case *jwt.SigningMethodECDSA:
+		return opts.ecKey()
+	case *jwt.SigningMethodHMAC:
+		return opts.hmacKey()
+	default:
+		return nil, fmt.Errorf("unsupported signing method: %T", opts.SignMethod)
+	}
+}
+
+func (opts *jwtOptions) hmacKey() (interface{}, error) {
+	if len(opts.PrivateKey) == 0 {
+		return nil, ErrMissingKey
+	}
+	return opts.PrivateKey, nil
+}
+
+func (opts *jwtOptions) rsaKey() (interface{}, error) {
+	var (
+		priv *rsa.PrivateKey
+		pub  *rsa.PublicKey
+		err  error
+	)
+
+	if len(opts.PrivateKey) > 0 {
+		priv, err = jwt.ParseRSAPrivateKeyFromPEM(opts.PrivateKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if len(opts.PublicKey) > 0 {
+		pub, err = jwt.ParseRSAPublicKeyFromPEM(opts.PublicKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if priv == nil {
+		if pub == nil {
+			// Neither key given
+			return nil, ErrMissingKey
+		}
+		// Public key only, can verify tokens
+		return pub, nil
+	}
+
+	// both keys provided, make sure they match
+	if pub != nil && pub.E != priv.E && pub.N.Cmp(priv.N) != 0 {
+		return nil, ErrKeyMismatch
+	}
+
+	return priv, nil
+}
+
+func (opts *jwtOptions) ecKey() (interface{}, error) {
+	var (
+		priv *ecdsa.PrivateKey
+		pub  *ecdsa.PublicKey
+		err  error
+	)
+
+	if len(opts.PrivateKey) > 0 {
+		priv, err = jwt.ParseECPrivateKeyFromPEM(opts.PrivateKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if len(opts.PublicKey) > 0 {
+		pub, err = jwt.ParseECPublicKeyFromPEM(opts.PublicKey)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if priv == nil {
+		if pub == nil {
+			// Neither key given
+			return nil, ErrMissingKey
+		}
+		// Public key only, can verify tokens
+		return pub, nil
+	}
+
+	// both keys provided, make sure they match
+	if pub != nil && pub.Curve != priv.Curve &&
+		pub.X.Cmp(priv.X) != 0 && pub.Y.Cmp(priv.Y) != 0 {
+		return nil, ErrKeyMismatch
+	}
+
+	return priv, nil
+}
diff --git a/vendor/go.etcd.io/etcd/auth/range_perm_cache.go b/vendor/go.etcd.io/etcd/auth/range_perm_cache.go
new file mode 100644
index 0000000..7b6c182
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/range_perm_cache.go
@@ -0,0 +1,153 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"go.etcd.io/etcd/auth/authpb"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/adt"
+
+	"go.uber.org/zap"
+)
+
+func getMergedPerms(lg *zap.Logger, tx backend.BatchTx, userName string) *unifiedRangePermissions {
+	user := getUser(lg, tx, userName)
+	if user == nil {
+		return nil
+	}
+
+	readPerms := adt.NewIntervalTree()
+	writePerms := adt.NewIntervalTree()
+
+	for _, roleName := range user.Roles {
+		role := getRole(tx, roleName)
+		if role == nil {
+			continue
+		}
+
+		for _, perm := range role.KeyPermission {
+			var ivl adt.Interval
+			var rangeEnd []byte
+
+			if len(perm.RangeEnd) != 1 || perm.RangeEnd[0] != 0 {
+				rangeEnd = perm.RangeEnd
+			}
+
+			if len(perm.RangeEnd) != 0 {
+				ivl = adt.NewBytesAffineInterval(perm.Key, rangeEnd)
+			} else {
+				ivl = adt.NewBytesAffinePoint(perm.Key)
+			}
+
+			switch perm.PermType {
+			case authpb.READWRITE:
+				readPerms.Insert(ivl, struct{}{})
+				writePerms.Insert(ivl, struct{}{})
+
+			case authpb.READ:
+				readPerms.Insert(ivl, struct{}{})
+
+			case authpb.WRITE:
+				writePerms.Insert(ivl, struct{}{})
+			}
+		}
+	}
+
+	return &unifiedRangePermissions{
+		readPerms:  readPerms,
+		writePerms: writePerms,
+	}
+}
+
+func checkKeyInterval(
+	lg *zap.Logger,
+	cachedPerms *unifiedRangePermissions,
+	key, rangeEnd []byte,
+	permtyp authpb.Permission_Type) bool {
+	if len(rangeEnd) == 1 && rangeEnd[0] == 0 {
+		rangeEnd = nil
+	}
+
+	ivl := adt.NewBytesAffineInterval(key, rangeEnd)
+	switch permtyp {
+	case authpb.READ:
+		return cachedPerms.readPerms.Contains(ivl)
+	case authpb.WRITE:
+		return cachedPerms.writePerms.Contains(ivl)
+	default:
+		if lg != nil {
+			lg.Panic("unknown auth type", zap.String("auth-type", permtyp.String()))
+		} else {
+			plog.Panicf("unknown auth type: %v", permtyp)
+		}
+	}
+	return false
+}
+
+func checkKeyPoint(lg *zap.Logger, cachedPerms *unifiedRangePermissions, key []byte, permtyp authpb.Permission_Type) bool {
+	pt := adt.NewBytesAffinePoint(key)
+	switch permtyp {
+	case authpb.READ:
+		return cachedPerms.readPerms.Intersects(pt)
+	case authpb.WRITE:
+		return cachedPerms.writePerms.Intersects(pt)
+	default:
+		if lg != nil {
+			lg.Panic("unknown auth type", zap.String("auth-type", permtyp.String()))
+		} else {
+			plog.Panicf("unknown auth type: %v", permtyp)
+		}
+	}
+	return false
+}
+
+func (as *authStore) isRangeOpPermitted(tx backend.BatchTx, userName string, key, rangeEnd []byte, permtyp authpb.Permission_Type) bool {
+	// assumption: tx is Lock()ed
+	_, ok := as.rangePermCache[userName]
+	if !ok {
+		perms := getMergedPerms(as.lg, tx, userName)
+		if perms == nil {
+			if as.lg != nil {
+				as.lg.Warn(
+					"failed to create a merged permission",
+					zap.String("user-name", userName),
+				)
+			} else {
+				plog.Errorf("failed to create a unified permission of user %s", userName)
+			}
+			return false
+		}
+		as.rangePermCache[userName] = perms
+	}
+
+	if len(rangeEnd) == 0 {
+		return checkKeyPoint(as.lg, as.rangePermCache[userName], key, permtyp)
+	}
+
+	return checkKeyInterval(as.lg, as.rangePermCache[userName], key, rangeEnd, permtyp)
+}
+
+func (as *authStore) clearCachedPerm() {
+	as.rangePermCache = make(map[string]*unifiedRangePermissions)
+}
+
+func (as *authStore) invalidateCachedPerm(userName string) {
+	delete(as.rangePermCache, userName)
+}
+
+type unifiedRangePermissions struct {
+	readPerms  adt.IntervalTree
+	writePerms adt.IntervalTree
+}
diff --git a/vendor/go.etcd.io/etcd/auth/simple_token.go b/vendor/go.etcd.io/etcd/auth/simple_token.go
new file mode 100644
index 0000000..934978c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/simple_token.go
@@ -0,0 +1,243 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+// CAUTION: This random number based token mechanism is only for testing purpose.
+// JWT based mechanism will be added in the near future.
+
+import (
+	"context"
+	"crypto/rand"
+	"fmt"
+	"math/big"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+const (
+	letters                  = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	defaultSimpleTokenLength = 16
+)
+
+// var for testing purposes
+var (
+	simpleTokenTTL           = 5 * time.Minute
+	simpleTokenTTLResolution = 1 * time.Second
+)
+
+type simpleTokenTTLKeeper struct {
+	tokens          map[string]time.Time
+	donec           chan struct{}
+	stopc           chan struct{}
+	deleteTokenFunc func(string)
+	mu              *sync.Mutex
+}
+
+func (tm *simpleTokenTTLKeeper) stop() {
+	select {
+	case tm.stopc <- struct{}{}:
+	case <-tm.donec:
+	}
+	<-tm.donec
+}
+
+func (tm *simpleTokenTTLKeeper) addSimpleToken(token string) {
+	tm.tokens[token] = time.Now().Add(simpleTokenTTL)
+}
+
+func (tm *simpleTokenTTLKeeper) resetSimpleToken(token string) {
+	if _, ok := tm.tokens[token]; ok {
+		tm.tokens[token] = time.Now().Add(simpleTokenTTL)
+	}
+}
+
+func (tm *simpleTokenTTLKeeper) deleteSimpleToken(token string) {
+	delete(tm.tokens, token)
+}
+
+func (tm *simpleTokenTTLKeeper) run() {
+	tokenTicker := time.NewTicker(simpleTokenTTLResolution)
+	defer func() {
+		tokenTicker.Stop()
+		close(tm.donec)
+	}()
+	for {
+		select {
+		case <-tokenTicker.C:
+			nowtime := time.Now()
+			tm.mu.Lock()
+			for t, tokenendtime := range tm.tokens {
+				if nowtime.After(tokenendtime) {
+					tm.deleteTokenFunc(t)
+					delete(tm.tokens, t)
+				}
+			}
+			tm.mu.Unlock()
+		case <-tm.stopc:
+			return
+		}
+	}
+}
+
+type tokenSimple struct {
+	lg                *zap.Logger
+	indexWaiter       func(uint64) <-chan struct{}
+	simpleTokenKeeper *simpleTokenTTLKeeper
+	simpleTokensMu    sync.Mutex
+	simpleTokens      map[string]string // token -> username
+}
+
+func (t *tokenSimple) genTokenPrefix() (string, error) {
+	ret := make([]byte, defaultSimpleTokenLength)
+
+	for i := 0; i < defaultSimpleTokenLength; i++ {
+		bInt, err := rand.Int(rand.Reader, big.NewInt(int64(len(letters))))
+		if err != nil {
+			return "", err
+		}
+
+		ret[i] = letters[bInt.Int64()]
+	}
+
+	return string(ret), nil
+}
+
+func (t *tokenSimple) assignSimpleTokenToUser(username, token string) {
+	t.simpleTokensMu.Lock()
+	defer t.simpleTokensMu.Unlock()
+	if t.simpleTokenKeeper == nil {
+		return
+	}
+
+	_, ok := t.simpleTokens[token]
+	if ok {
+		if t.lg != nil {
+			t.lg.Panic(
+				"failed to assign already-used simple token to a user",
+				zap.String("user-name", username),
+				zap.String("token", token),
+			)
+		} else {
+			plog.Panicf("token %s is already used", token)
+		}
+	}
+
+	t.simpleTokens[token] = username
+	t.simpleTokenKeeper.addSimpleToken(token)
+}
+
+func (t *tokenSimple) invalidateUser(username string) {
+	if t.simpleTokenKeeper == nil {
+		return
+	}
+	t.simpleTokensMu.Lock()
+	for token, name := range t.simpleTokens {
+		if name == username {
+			delete(t.simpleTokens, token)
+			t.simpleTokenKeeper.deleteSimpleToken(token)
+		}
+	}
+	t.simpleTokensMu.Unlock()
+}
+
+func (t *tokenSimple) enable() {
+	delf := func(tk string) {
+		if username, ok := t.simpleTokens[tk]; ok {
+			if t.lg != nil {
+				t.lg.Info(
+					"deleted a simple token",
+					zap.String("user-name", username),
+					zap.String("token", tk),
+				)
+			} else {
+				plog.Infof("deleting token %s for user %s", tk, username)
+			}
+			delete(t.simpleTokens, tk)
+		}
+	}
+	t.simpleTokenKeeper = &simpleTokenTTLKeeper{
+		tokens:          make(map[string]time.Time),
+		donec:           make(chan struct{}),
+		stopc:           make(chan struct{}),
+		deleteTokenFunc: delf,
+		mu:              &t.simpleTokensMu,
+	}
+	go t.simpleTokenKeeper.run()
+}
+
+func (t *tokenSimple) disable() {
+	t.simpleTokensMu.Lock()
+	tk := t.simpleTokenKeeper
+	t.simpleTokenKeeper = nil
+	t.simpleTokens = make(map[string]string) // invalidate all tokens
+	t.simpleTokensMu.Unlock()
+	if tk != nil {
+		tk.stop()
+	}
+}
+
+func (t *tokenSimple) info(ctx context.Context, token string, revision uint64) (*AuthInfo, bool) {
+	if !t.isValidSimpleToken(ctx, token) {
+		return nil, false
+	}
+	t.simpleTokensMu.Lock()
+	username, ok := t.simpleTokens[token]
+	if ok && t.simpleTokenKeeper != nil {
+		t.simpleTokenKeeper.resetSimpleToken(token)
+	}
+	t.simpleTokensMu.Unlock()
+	return &AuthInfo{Username: username, Revision: revision}, ok
+}
+
+func (t *tokenSimple) assign(ctx context.Context, username string, rev uint64) (string, error) {
+	// rev isn't used in simple token, it is only used in JWT
+	index := ctx.Value(AuthenticateParamIndex{}).(uint64)
+	simpleTokenPrefix := ctx.Value(AuthenticateParamSimpleTokenPrefix{}).(string)
+	token := fmt.Sprintf("%s.%d", simpleTokenPrefix, index)
+	t.assignSimpleTokenToUser(username, token)
+
+	return token, nil
+}
+
+func (t *tokenSimple) isValidSimpleToken(ctx context.Context, token string) bool {
+	splitted := strings.Split(token, ".")
+	if len(splitted) != 2 {
+		return false
+	}
+	index, err := strconv.Atoi(splitted[1])
+	if err != nil {
+		return false
+	}
+
+	select {
+	case <-t.indexWaiter(uint64(index)):
+		return true
+	case <-ctx.Done():
+	}
+
+	return false
+}
+
+func newTokenProviderSimple(lg *zap.Logger, indexWaiter func(uint64) <-chan struct{}) *tokenSimple {
+	return &tokenSimple{
+		lg:           lg,
+		simpleTokens: make(map[string]string),
+		indexWaiter:  indexWaiter,
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/auth/store.go b/vendor/go.etcd.io/etcd/auth/store.go
new file mode 100644
index 0000000..5212255
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/auth/store.go
@@ -0,0 +1,1420 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package auth
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"errors"
+	"sort"
+	"strings"
+	"sync"
+	"sync/atomic"
+
+	"go.etcd.io/etcd/auth/authpb"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc/backend"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+	"golang.org/x/crypto/bcrypt"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+)
+
+var (
+	enableFlagKey = []byte("authEnabled")
+	authEnabled   = []byte{1}
+	authDisabled  = []byte{0}
+
+	revisionKey = []byte("authRevision")
+
+	authBucketName      = []byte("auth")
+	authUsersBucketName = []byte("authUsers")
+	authRolesBucketName = []byte("authRoles")
+
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "auth")
+
+	ErrRootUserNotExist     = errors.New("auth: root user does not exist")
+	ErrRootRoleNotExist     = errors.New("auth: root user does not have root role")
+	ErrUserAlreadyExist     = errors.New("auth: user already exists")
+	ErrUserEmpty            = errors.New("auth: user name is empty")
+	ErrUserNotFound         = errors.New("auth: user not found")
+	ErrRoleAlreadyExist     = errors.New("auth: role already exists")
+	ErrRoleNotFound         = errors.New("auth: role not found")
+	ErrRoleEmpty            = errors.New("auth: role name is empty")
+	ErrAuthFailed           = errors.New("auth: authentication failed, invalid user ID or password")
+	ErrPermissionDenied     = errors.New("auth: permission denied")
+	ErrRoleNotGranted       = errors.New("auth: role is not granted to the user")
+	ErrPermissionNotGranted = errors.New("auth: permission is not granted to the role")
+	ErrAuthNotEnabled       = errors.New("auth: authentication is not enabled")
+	ErrAuthOldRevision      = errors.New("auth: revision in header is old")
+	ErrInvalidAuthToken     = errors.New("auth: invalid auth token")
+	ErrInvalidAuthOpts      = errors.New("auth: invalid auth options")
+	ErrInvalidAuthMgmt      = errors.New("auth: invalid auth management")
+	ErrInvalidAuthMethod    = errors.New("auth: invalid auth signature method")
+	ErrMissingKey           = errors.New("auth: missing key data")
+	ErrKeyMismatch          = errors.New("auth: public and private keys don't match")
+	ErrVerifyOnly           = errors.New("auth: token signing attempted with verify-only key")
+)
+
+const (
+	rootUser = "root"
+	rootRole = "root"
+
+	tokenTypeSimple = "simple"
+	tokenTypeJWT    = "jwt"
+
+	revBytesLen = 8
+)
+
+type AuthInfo struct {
+	Username string
+	Revision uint64
+}
+
+// AuthenticateParamIndex is used for a key of context in the parameters of Authenticate()
+type AuthenticateParamIndex struct{}
+
+// AuthenticateParamSimpleTokenPrefix is used for a key of context in the parameters of Authenticate()
+type AuthenticateParamSimpleTokenPrefix struct{}
+
+// AuthStore defines auth storage interface.
+type AuthStore interface {
+	// AuthEnable turns on the authentication feature
+	AuthEnable() error
+
+	// AuthDisable turns off the authentication feature
+	AuthDisable()
+
+	// IsAuthEnabled returns true if the authentication feature is enabled.
+	IsAuthEnabled() bool
+
+	// Authenticate does authentication based on given user name and password
+	Authenticate(ctx context.Context, username, password string) (*pb.AuthenticateResponse, error)
+
+	// Recover recovers the state of auth store from the given backend
+	Recover(b backend.Backend)
+
+	// UserAdd adds a new user
+	UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
+
+	// UserDelete deletes a user
+	UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
+
+	// UserChangePassword changes a password of a user
+	UserChangePassword(r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error)
+
+	// UserGrantRole grants a role to the user
+	UserGrantRole(r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error)
+
+	// UserGet gets the detailed information of a users
+	UserGet(r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error)
+
+	// UserRevokeRole revokes a role of a user
+	UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error)
+
+	// RoleAdd adds a new role
+	RoleAdd(r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error)
+
+	// RoleGrantPermission grants a permission to a role
+	RoleGrantPermission(r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error)
+
+	// RoleGet gets the detailed information of a role
+	RoleGet(r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error)
+
+	// RoleRevokePermission gets the detailed information of a role
+	RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error)
+
+	// RoleDelete gets the detailed information of a role
+	RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
+
+	// UserList gets a list of all users
+	UserList(r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
+
+	// RoleList gets a list of all roles
+	RoleList(r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
+
+	// IsPutPermitted checks put permission of the user
+	IsPutPermitted(authInfo *AuthInfo, key []byte) error
+
+	// IsRangePermitted checks range permission of the user
+	IsRangePermitted(authInfo *AuthInfo, key, rangeEnd []byte) error
+
+	// IsDeleteRangePermitted checks delete-range permission of the user
+	IsDeleteRangePermitted(authInfo *AuthInfo, key, rangeEnd []byte) error
+
+	// IsAdminPermitted checks admin permission of the user
+	IsAdminPermitted(authInfo *AuthInfo) error
+
+	// GenTokenPrefix produces a random string in a case of simple token
+	// in a case of JWT, it produces an empty string
+	GenTokenPrefix() (string, error)
+
+	// Revision gets current revision of authStore
+	Revision() uint64
+
+	// CheckPassword checks a given pair of username and password is correct
+	CheckPassword(username, password string) (uint64, error)
+
+	// Close does cleanup of AuthStore
+	Close() error
+
+	// AuthInfoFromCtx gets AuthInfo from gRPC's context
+	AuthInfoFromCtx(ctx context.Context) (*AuthInfo, error)
+
+	// AuthInfoFromTLS gets AuthInfo from TLS info of gRPC's context
+	AuthInfoFromTLS(ctx context.Context) *AuthInfo
+
+	// WithRoot generates and installs a token that can be used as a root credential
+	WithRoot(ctx context.Context) context.Context
+
+	// HasRole checks that user has role
+	HasRole(user, role string) bool
+}
+
+type TokenProvider interface {
+	info(ctx context.Context, token string, revision uint64) (*AuthInfo, bool)
+	assign(ctx context.Context, username string, revision uint64) (string, error)
+	enable()
+	disable()
+
+	invalidateUser(string)
+	genTokenPrefix() (string, error)
+}
+
+type authStore struct {
+	// atomic operations; need 64-bit align, or 32-bit tests will crash
+	revision uint64
+
+	lg        *zap.Logger
+	be        backend.Backend
+	enabled   bool
+	enabledMu sync.RWMutex
+
+	rangePermCache map[string]*unifiedRangePermissions // username -> unifiedRangePermissions
+
+	tokenProvider TokenProvider
+	bcryptCost    int // the algorithm cost / strength for hashing auth passwords
+}
+
+func (as *authStore) AuthEnable() error {
+	as.enabledMu.Lock()
+	defer as.enabledMu.Unlock()
+	if as.enabled {
+		if as.lg != nil {
+			as.lg.Info("authentication is already enabled; ignored auth enable request")
+		} else {
+			plog.Noticef("Authentication already enabled")
+		}
+		return nil
+	}
+	b := as.be
+	tx := b.BatchTx()
+	tx.Lock()
+	defer func() {
+		tx.Unlock()
+		b.ForceCommit()
+	}()
+
+	u := getUser(as.lg, tx, rootUser)
+	if u == nil {
+		return ErrRootUserNotExist
+	}
+
+	if !hasRootRole(u) {
+		return ErrRootRoleNotExist
+	}
+
+	tx.UnsafePut(authBucketName, enableFlagKey, authEnabled)
+
+	as.enabled = true
+	as.tokenProvider.enable()
+
+	as.rangePermCache = make(map[string]*unifiedRangePermissions)
+
+	as.setRevision(getRevision(tx))
+
+	if as.lg != nil {
+		as.lg.Info("enabled authentication")
+	} else {
+		plog.Noticef("Authentication enabled")
+	}
+	return nil
+}
+
+func (as *authStore) AuthDisable() {
+	as.enabledMu.Lock()
+	defer as.enabledMu.Unlock()
+	if !as.enabled {
+		return
+	}
+	b := as.be
+	tx := b.BatchTx()
+	tx.Lock()
+	tx.UnsafePut(authBucketName, enableFlagKey, authDisabled)
+	as.commitRevision(tx)
+	tx.Unlock()
+	b.ForceCommit()
+
+	as.enabled = false
+	as.tokenProvider.disable()
+
+	if as.lg != nil {
+		as.lg.Info("disabled authentication")
+	} else {
+		plog.Noticef("Authentication disabled")
+	}
+}
+
+func (as *authStore) Close() error {
+	as.enabledMu.Lock()
+	defer as.enabledMu.Unlock()
+	if !as.enabled {
+		return nil
+	}
+	as.tokenProvider.disable()
+	return nil
+}
+
+func (as *authStore) Authenticate(ctx context.Context, username, password string) (*pb.AuthenticateResponse, error) {
+	if !as.IsAuthEnabled() {
+		return nil, ErrAuthNotEnabled
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, username)
+	if user == nil {
+		return nil, ErrAuthFailed
+	}
+
+	if user.Options.NoPassword {
+		return nil, ErrAuthFailed
+	}
+
+	// Password checking is already performed in the API layer, so we don't need to check for now.
+	// Staleness of password can be detected with OCC in the API layer, too.
+
+	token, err := as.tokenProvider.assign(ctx, username, as.Revision())
+	if err != nil {
+		return nil, err
+	}
+
+	if as.lg != nil {
+		as.lg.Debug(
+			"authenticated a user",
+			zap.String("user-name", username),
+			zap.String("token", token),
+		)
+	} else {
+		plog.Debugf("authorized %s, token is %s", username, token)
+	}
+	return &pb.AuthenticateResponse{Token: token}, nil
+}
+
+func (as *authStore) CheckPassword(username, password string) (uint64, error) {
+	if !as.IsAuthEnabled() {
+		return 0, ErrAuthNotEnabled
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, username)
+	if user == nil {
+		return 0, ErrAuthFailed
+	}
+
+	if user.Options.NoPassword {
+		return 0, ErrAuthFailed
+	}
+
+	if bcrypt.CompareHashAndPassword(user.Password, []byte(password)) != nil {
+		if as.lg != nil {
+			as.lg.Info("invalid password", zap.String("user-name", username))
+		} else {
+			plog.Noticef("authentication failed, invalid password for user %s", username)
+		}
+		return 0, ErrAuthFailed
+	}
+	return getRevision(tx), nil
+}
+
+func (as *authStore) Recover(be backend.Backend) {
+	enabled := false
+	as.be = be
+	tx := be.BatchTx()
+	tx.Lock()
+	_, vs := tx.UnsafeRange(authBucketName, enableFlagKey, nil, 0)
+	if len(vs) == 1 {
+		if bytes.Equal(vs[0], authEnabled) {
+			enabled = true
+		}
+	}
+
+	as.setRevision(getRevision(tx))
+
+	tx.Unlock()
+
+	as.enabledMu.Lock()
+	as.enabled = enabled
+	as.enabledMu.Unlock()
+}
+
+func (as *authStore) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error) {
+	if len(r.Name) == 0 {
+		return nil, ErrUserEmpty
+	}
+
+	var hashed []byte
+	var err error
+
+	if r.Options != nil && !r.Options.NoPassword {
+		hashed, err = bcrypt.GenerateFromPassword([]byte(r.Password), as.bcryptCost)
+		if err != nil {
+			if as.lg != nil {
+				as.lg.Warn(
+					"failed to bcrypt hash password",
+					zap.String("user-name", r.Name),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("failed to hash password: %s", err)
+			}
+			return nil, err
+		}
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, r.Name)
+	if user != nil {
+		return nil, ErrUserAlreadyExist
+	}
+
+	options := r.Options
+	if options == nil {
+		options = &authpb.UserAddOptions{
+			NoPassword: false,
+		}
+	}
+
+	newUser := &authpb.User{
+		Name:     []byte(r.Name),
+		Password: hashed,
+		Options:  options,
+	}
+
+	putUser(as.lg, tx, newUser)
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info("added a user", zap.String("user-name", r.Name))
+	} else {
+		plog.Noticef("added a new user: %s", r.Name)
+	}
+	return &pb.AuthUserAddResponse{}, nil
+}
+
+func (as *authStore) UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	if as.enabled && r.Name == rootUser {
+		if as.lg != nil {
+			as.lg.Warn("cannot delete 'root' user", zap.String("user-name", r.Name))
+		} else {
+			plog.Errorf("the user root must not be deleted")
+		}
+		return nil, ErrInvalidAuthMgmt
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, r.Name)
+	if user == nil {
+		return nil, ErrUserNotFound
+	}
+
+	delUser(tx, r.Name)
+
+	as.commitRevision(tx)
+
+	as.invalidateCachedPerm(r.Name)
+	as.tokenProvider.invalidateUser(r.Name)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"deleted a user",
+			zap.String("user-name", r.Name),
+			zap.Strings("user-roles", user.Roles),
+		)
+	} else {
+		plog.Noticef("deleted a user: %s", r.Name)
+	}
+	return &pb.AuthUserDeleteResponse{}, nil
+}
+
+func (as *authStore) UserChangePassword(r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error) {
+	// TODO(mitake): measure the cost of bcrypt.GenerateFromPassword()
+	// If the cost is too high, we should move the encryption to outside of the raft
+	hashed, err := bcrypt.GenerateFromPassword([]byte(r.Password), as.bcryptCost)
+	if err != nil {
+		if as.lg != nil {
+			as.lg.Warn(
+				"failed to bcrypt hash password",
+				zap.String("user-name", r.Name),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to hash password: %s", err)
+		}
+		return nil, err
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, r.Name)
+	if user == nil {
+		return nil, ErrUserNotFound
+	}
+
+	updatedUser := &authpb.User{
+		Name:     []byte(r.Name),
+		Roles:    user.Roles,
+		Password: hashed,
+		Options:  user.Options,
+	}
+
+	putUser(as.lg, tx, updatedUser)
+
+	as.commitRevision(tx)
+
+	as.invalidateCachedPerm(r.Name)
+	as.tokenProvider.invalidateUser(r.Name)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"changed a password of a user",
+			zap.String("user-name", r.Name),
+			zap.Strings("user-roles", user.Roles),
+		)
+	} else {
+		plog.Noticef("changed a password of a user: %s", r.Name)
+	}
+	return &pb.AuthUserChangePasswordResponse{}, nil
+}
+
+func (as *authStore) UserGrantRole(r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, r.User)
+	if user == nil {
+		return nil, ErrUserNotFound
+	}
+
+	if r.Role != rootRole {
+		role := getRole(tx, r.Role)
+		if role == nil {
+			return nil, ErrRoleNotFound
+		}
+	}
+
+	idx := sort.SearchStrings(user.Roles, r.Role)
+	if idx < len(user.Roles) && user.Roles[idx] == r.Role {
+		if as.lg != nil {
+			as.lg.Warn(
+				"ignored grant role request to a user",
+				zap.String("user-name", r.User),
+				zap.Strings("user-roles", user.Roles),
+				zap.String("duplicate-role-name", r.Role),
+			)
+		} else {
+			plog.Warningf("user %s is already granted role %s", r.User, r.Role)
+		}
+		return &pb.AuthUserGrantRoleResponse{}, nil
+	}
+
+	user.Roles = append(user.Roles, r.Role)
+	sort.Strings(user.Roles)
+
+	putUser(as.lg, tx, user)
+
+	as.invalidateCachedPerm(r.User)
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"granted a role to a user",
+			zap.String("user-name", r.User),
+			zap.Strings("user-roles", user.Roles),
+			zap.String("added-role-name", r.Role),
+		)
+	} else {
+		plog.Noticef("granted role %s to user %s", r.Role, r.User)
+	}
+	return &pb.AuthUserGrantRoleResponse{}, nil
+}
+
+func (as *authStore) UserGet(r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	user := getUser(as.lg, tx, r.Name)
+	tx.Unlock()
+
+	if user == nil {
+		return nil, ErrUserNotFound
+	}
+
+	var resp pb.AuthUserGetResponse
+	resp.Roles = append(resp.Roles, user.Roles...)
+	return &resp, nil
+}
+
+func (as *authStore) UserList(r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	users := getAllUsers(as.lg, tx)
+	tx.Unlock()
+
+	resp := &pb.AuthUserListResponse{Users: make([]string, len(users))}
+	for i := range users {
+		resp.Users[i] = string(users[i].Name)
+	}
+	return resp, nil
+}
+
+func (as *authStore) UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	if as.enabled && r.Name == rootUser && r.Role == rootRole {
+		if as.lg != nil {
+			as.lg.Warn(
+				"'root' user cannot revoke 'root' role",
+				zap.String("user-name", r.Name),
+				zap.String("role-name", r.Role),
+			)
+		} else {
+			plog.Errorf("the role root must not be revoked from the user root")
+		}
+		return nil, ErrInvalidAuthMgmt
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, r.Name)
+	if user == nil {
+		return nil, ErrUserNotFound
+	}
+
+	updatedUser := &authpb.User{
+		Name:     user.Name,
+		Password: user.Password,
+		Options:  user.Options,
+	}
+
+	for _, role := range user.Roles {
+		if role != r.Role {
+			updatedUser.Roles = append(updatedUser.Roles, role)
+		}
+	}
+
+	if len(updatedUser.Roles) == len(user.Roles) {
+		return nil, ErrRoleNotGranted
+	}
+
+	putUser(as.lg, tx, updatedUser)
+
+	as.invalidateCachedPerm(r.Name)
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"revoked a role from a user",
+			zap.String("user-name", r.Name),
+			zap.Strings("old-user-roles", user.Roles),
+			zap.Strings("new-user-roles", updatedUser.Roles),
+			zap.String("revoked-role-name", r.Role),
+		)
+	} else {
+		plog.Noticef("revoked role %s from user %s", r.Role, r.Name)
+	}
+	return &pb.AuthUserRevokeRoleResponse{}, nil
+}
+
+func (as *authStore) RoleGet(r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	var resp pb.AuthRoleGetResponse
+
+	role := getRole(tx, r.Role)
+	if role == nil {
+		return nil, ErrRoleNotFound
+	}
+	resp.Perm = append(resp.Perm, role.KeyPermission...)
+	return &resp, nil
+}
+
+func (as *authStore) RoleList(r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	roles := getAllRoles(as.lg, tx)
+	tx.Unlock()
+
+	resp := &pb.AuthRoleListResponse{Roles: make([]string, len(roles))}
+	for i := range roles {
+		resp.Roles[i] = string(roles[i].Name)
+	}
+	return resp, nil
+}
+
+func (as *authStore) RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	role := getRole(tx, r.Role)
+	if role == nil {
+		return nil, ErrRoleNotFound
+	}
+
+	updatedRole := &authpb.Role{
+		Name: role.Name,
+	}
+
+	for _, perm := range role.KeyPermission {
+		if !bytes.Equal(perm.Key, r.Key) || !bytes.Equal(perm.RangeEnd, r.RangeEnd) {
+			updatedRole.KeyPermission = append(updatedRole.KeyPermission, perm)
+		}
+	}
+
+	if len(role.KeyPermission) == len(updatedRole.KeyPermission) {
+		return nil, ErrPermissionNotGranted
+	}
+
+	putRole(as.lg, tx, updatedRole)
+
+	// TODO(mitake): currently single role update invalidates every cache
+	// It should be optimized.
+	as.clearCachedPerm()
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"revoked a permission on range",
+			zap.String("role-name", r.Role),
+			zap.String("key", string(r.Key)),
+			zap.String("range-end", string(r.RangeEnd)),
+		)
+	} else {
+		plog.Noticef("revoked key %s from role %s", r.Key, r.Role)
+	}
+	return &pb.AuthRoleRevokePermissionResponse{}, nil
+}
+
+func (as *authStore) RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	if as.enabled && r.Role == rootRole {
+		if as.lg != nil {
+			as.lg.Warn("cannot delete 'root' role", zap.String("role-name", r.Role))
+		} else {
+			plog.Errorf("the role root must not be deleted")
+		}
+		return nil, ErrInvalidAuthMgmt
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	role := getRole(tx, r.Role)
+	if role == nil {
+		return nil, ErrRoleNotFound
+	}
+
+	delRole(tx, r.Role)
+
+	users := getAllUsers(as.lg, tx)
+	for _, user := range users {
+		updatedUser := &authpb.User{
+			Name:     user.Name,
+			Password: user.Password,
+			Options:  user.Options,
+		}
+
+		for _, role := range user.Roles {
+			if role != r.Role {
+				updatedUser.Roles = append(updatedUser.Roles, role)
+			}
+		}
+
+		if len(updatedUser.Roles) == len(user.Roles) {
+			continue
+		}
+
+		putUser(as.lg, tx, updatedUser)
+
+		as.invalidateCachedPerm(string(user.Name))
+	}
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info("deleted a role", zap.String("role-name", r.Role))
+	} else {
+		plog.Noticef("deleted role %s", r.Role)
+	}
+	return &pb.AuthRoleDeleteResponse{}, nil
+}
+
+func (as *authStore) RoleAdd(r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error) {
+	if len(r.Name) == 0 {
+		return nil, ErrRoleEmpty
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	role := getRole(tx, r.Name)
+	if role != nil {
+		return nil, ErrRoleAlreadyExist
+	}
+
+	newRole := &authpb.Role{
+		Name: []byte(r.Name),
+	}
+
+	putRole(as.lg, tx, newRole)
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info("created a role", zap.String("role-name", r.Name))
+	} else {
+		plog.Noticef("Role %s is created", r.Name)
+	}
+	return &pb.AuthRoleAddResponse{}, nil
+}
+
+func (as *authStore) authInfoFromToken(ctx context.Context, token string) (*AuthInfo, bool) {
+	return as.tokenProvider.info(ctx, token, as.Revision())
+}
+
+type permSlice []*authpb.Permission
+
+func (perms permSlice) Len() int {
+	return len(perms)
+}
+
+func (perms permSlice) Less(i, j int) bool {
+	return bytes.Compare(perms[i].Key, perms[j].Key) < 0
+}
+
+func (perms permSlice) Swap(i, j int) {
+	perms[i], perms[j] = perms[j], perms[i]
+}
+
+func (as *authStore) RoleGrantPermission(r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error) {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	role := getRole(tx, r.Name)
+	if role == nil {
+		return nil, ErrRoleNotFound
+	}
+
+	idx := sort.Search(len(role.KeyPermission), func(i int) bool {
+		return bytes.Compare(role.KeyPermission[i].Key, r.Perm.Key) >= 0
+	})
+
+	if idx < len(role.KeyPermission) && bytes.Equal(role.KeyPermission[idx].Key, r.Perm.Key) && bytes.Equal(role.KeyPermission[idx].RangeEnd, r.Perm.RangeEnd) {
+		// update existing permission
+		role.KeyPermission[idx].PermType = r.Perm.PermType
+	} else {
+		// append new permission to the role
+		newPerm := &authpb.Permission{
+			Key:      r.Perm.Key,
+			RangeEnd: r.Perm.RangeEnd,
+			PermType: r.Perm.PermType,
+		}
+
+		role.KeyPermission = append(role.KeyPermission, newPerm)
+		sort.Sort(permSlice(role.KeyPermission))
+	}
+
+	putRole(as.lg, tx, role)
+
+	// TODO(mitake): currently single role update invalidates every cache
+	// It should be optimized.
+	as.clearCachedPerm()
+
+	as.commitRevision(tx)
+
+	if as.lg != nil {
+		as.lg.Info(
+			"granted/updated a permission to a user",
+			zap.String("user-name", r.Name),
+			zap.String("permission-name", authpb.Permission_Type_name[int32(r.Perm.PermType)]),
+		)
+	} else {
+		plog.Noticef("role %s's permission of key %s is updated as %s", r.Name, r.Perm.Key, authpb.Permission_Type_name[int32(r.Perm.PermType)])
+	}
+	return &pb.AuthRoleGrantPermissionResponse{}, nil
+}
+
+func (as *authStore) isOpPermitted(userName string, revision uint64, key, rangeEnd []byte, permTyp authpb.Permission_Type) error {
+	// TODO(mitake): this function would be costly so we need a caching mechanism
+	if !as.IsAuthEnabled() {
+		return nil
+	}
+
+	// only gets rev == 0 when passed AuthInfo{}; no user given
+	if revision == 0 {
+		return ErrUserEmpty
+	}
+
+	if revision < as.Revision() {
+		return ErrAuthOldRevision
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	user := getUser(as.lg, tx, userName)
+	if user == nil {
+		if as.lg != nil {
+			as.lg.Warn("cannot find a user for permission check", zap.String("user-name", userName))
+		} else {
+			plog.Errorf("invalid user name %s for permission checking", userName)
+		}
+		return ErrPermissionDenied
+	}
+
+	// root role should have permission on all ranges
+	if hasRootRole(user) {
+		return nil
+	}
+
+	if as.isRangeOpPermitted(tx, userName, key, rangeEnd, permTyp) {
+		return nil
+	}
+
+	return ErrPermissionDenied
+}
+
+func (as *authStore) IsPutPermitted(authInfo *AuthInfo, key []byte) error {
+	return as.isOpPermitted(authInfo.Username, authInfo.Revision, key, nil, authpb.WRITE)
+}
+
+func (as *authStore) IsRangePermitted(authInfo *AuthInfo, key, rangeEnd []byte) error {
+	return as.isOpPermitted(authInfo.Username, authInfo.Revision, key, rangeEnd, authpb.READ)
+}
+
+func (as *authStore) IsDeleteRangePermitted(authInfo *AuthInfo, key, rangeEnd []byte) error {
+	return as.isOpPermitted(authInfo.Username, authInfo.Revision, key, rangeEnd, authpb.WRITE)
+}
+
+func (as *authStore) IsAdminPermitted(authInfo *AuthInfo) error {
+	if !as.IsAuthEnabled() {
+		return nil
+	}
+	if authInfo == nil {
+		return ErrUserEmpty
+	}
+
+	tx := as.be.BatchTx()
+	tx.Lock()
+	u := getUser(as.lg, tx, authInfo.Username)
+	tx.Unlock()
+
+	if u == nil {
+		return ErrUserNotFound
+	}
+
+	if !hasRootRole(u) {
+		return ErrPermissionDenied
+	}
+
+	return nil
+}
+
+func getUser(lg *zap.Logger, tx backend.BatchTx, username string) *authpb.User {
+	_, vs := tx.UnsafeRange(authUsersBucketName, []byte(username), nil, 0)
+	if len(vs) == 0 {
+		return nil
+	}
+
+	user := &authpb.User{}
+	err := user.Unmarshal(vs[0])
+	if err != nil {
+		if lg != nil {
+			lg.Panic(
+				"failed to unmarshal 'authpb.User'",
+				zap.String("user-name", username),
+				zap.Error(err),
+			)
+		} else {
+			plog.Panicf("failed to unmarshal user struct (name: %s): %s", username, err)
+		}
+	}
+	return user
+}
+
+func getAllUsers(lg *zap.Logger, tx backend.BatchTx) []*authpb.User {
+	_, vs := tx.UnsafeRange(authUsersBucketName, []byte{0}, []byte{0xff}, -1)
+	if len(vs) == 0 {
+		return nil
+	}
+
+	users := make([]*authpb.User, len(vs))
+	for i := range vs {
+		user := &authpb.User{}
+		err := user.Unmarshal(vs[i])
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to unmarshal 'authpb.User'", zap.Error(err))
+			} else {
+				plog.Panicf("failed to unmarshal user struct: %s", err)
+			}
+		}
+		users[i] = user
+	}
+	return users
+}
+
+func putUser(lg *zap.Logger, tx backend.BatchTx, user *authpb.User) {
+	b, err := user.Marshal()
+	if err != nil {
+		if lg != nil {
+			lg.Panic("failed to unmarshal 'authpb.User'", zap.Error(err))
+		} else {
+			plog.Panicf("failed to marshal user struct (name: %s): %s", user.Name, err)
+		}
+	}
+	tx.UnsafePut(authUsersBucketName, user.Name, b)
+}
+
+func delUser(tx backend.BatchTx, username string) {
+	tx.UnsafeDelete(authUsersBucketName, []byte(username))
+}
+
+func getRole(tx backend.BatchTx, rolename string) *authpb.Role {
+	_, vs := tx.UnsafeRange(authRolesBucketName, []byte(rolename), nil, 0)
+	if len(vs) == 0 {
+		return nil
+	}
+
+	role := &authpb.Role{}
+	err := role.Unmarshal(vs[0])
+	if err != nil {
+		plog.Panicf("failed to unmarshal role struct (name: %s): %s", rolename, err)
+	}
+	return role
+}
+
+func getAllRoles(lg *zap.Logger, tx backend.BatchTx) []*authpb.Role {
+	_, vs := tx.UnsafeRange(authRolesBucketName, []byte{0}, []byte{0xff}, -1)
+	if len(vs) == 0 {
+		return nil
+	}
+
+	roles := make([]*authpb.Role, len(vs))
+	for i := range vs {
+		role := &authpb.Role{}
+		err := role.Unmarshal(vs[i])
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to unmarshal 'authpb.Role'", zap.Error(err))
+			} else {
+				plog.Panicf("failed to unmarshal role struct: %s", err)
+			}
+		}
+		roles[i] = role
+	}
+	return roles
+}
+
+func putRole(lg *zap.Logger, tx backend.BatchTx, role *authpb.Role) {
+	b, err := role.Marshal()
+	if err != nil {
+		if lg != nil {
+			lg.Panic(
+				"failed to marshal 'authpb.Role'",
+				zap.String("role-name", string(role.Name)),
+				zap.Error(err),
+			)
+		} else {
+			plog.Panicf("failed to marshal role struct (name: %s): %s", role.Name, err)
+		}
+	}
+
+	tx.UnsafePut(authRolesBucketName, role.Name, b)
+}
+
+func delRole(tx backend.BatchTx, rolename string) {
+	tx.UnsafeDelete(authRolesBucketName, []byte(rolename))
+}
+
+func (as *authStore) IsAuthEnabled() bool {
+	as.enabledMu.RLock()
+	defer as.enabledMu.RUnlock()
+	return as.enabled
+}
+
+// NewAuthStore creates a new AuthStore.
+func NewAuthStore(lg *zap.Logger, be backend.Backend, tp TokenProvider, bcryptCost int) *authStore {
+	if bcryptCost < bcrypt.MinCost || bcryptCost > bcrypt.MaxCost {
+		if lg != nil {
+			lg.Warn(
+				"use default bcrypt cost instead of the invalid given cost",
+				zap.Int("min-cost", bcrypt.MinCost),
+				zap.Int("max-cost", bcrypt.MaxCost),
+				zap.Int("default-cost", bcrypt.DefaultCost),
+				zap.Int("given-cost", bcryptCost))
+		} else {
+			plog.Warningf("Use default bcrypt-cost %d instead of the invalid value %d",
+				bcrypt.DefaultCost, bcryptCost)
+		}
+
+		bcryptCost = bcrypt.DefaultCost
+	}
+
+	tx := be.BatchTx()
+	tx.Lock()
+
+	tx.UnsafeCreateBucket(authBucketName)
+	tx.UnsafeCreateBucket(authUsersBucketName)
+	tx.UnsafeCreateBucket(authRolesBucketName)
+
+	enabled := false
+	_, vs := tx.UnsafeRange(authBucketName, enableFlagKey, nil, 0)
+	if len(vs) == 1 {
+		if bytes.Equal(vs[0], authEnabled) {
+			enabled = true
+		}
+	}
+
+	as := &authStore{
+		revision:       getRevision(tx),
+		lg:             lg,
+		be:             be,
+		enabled:        enabled,
+		rangePermCache: make(map[string]*unifiedRangePermissions),
+		tokenProvider:  tp,
+		bcryptCost:     bcryptCost,
+	}
+
+	if enabled {
+		as.tokenProvider.enable()
+	}
+
+	if as.Revision() == 0 {
+		as.commitRevision(tx)
+	}
+
+	tx.Unlock()
+	be.ForceCommit()
+
+	return as
+}
+
+func hasRootRole(u *authpb.User) bool {
+	// u.Roles is sorted in UserGrantRole(), so we can use binary search.
+	idx := sort.SearchStrings(u.Roles, rootRole)
+	return idx != len(u.Roles) && u.Roles[idx] == rootRole
+}
+
+func (as *authStore) commitRevision(tx backend.BatchTx) {
+	atomic.AddUint64(&as.revision, 1)
+	revBytes := make([]byte, revBytesLen)
+	binary.BigEndian.PutUint64(revBytes, as.Revision())
+	tx.UnsafePut(authBucketName, revisionKey, revBytes)
+}
+
+func getRevision(tx backend.BatchTx) uint64 {
+	_, vs := tx.UnsafeRange(authBucketName, revisionKey, nil, 0)
+	if len(vs) != 1 {
+		// this can happen in the initialization phase
+		return 0
+	}
+	return binary.BigEndian.Uint64(vs[0])
+}
+
+func (as *authStore) setRevision(rev uint64) {
+	atomic.StoreUint64(&as.revision, rev)
+}
+
+func (as *authStore) Revision() uint64 {
+	return atomic.LoadUint64(&as.revision)
+}
+
+func (as *authStore) AuthInfoFromTLS(ctx context.Context) (ai *AuthInfo) {
+	peer, ok := peer.FromContext(ctx)
+	if !ok || peer == nil || peer.AuthInfo == nil {
+		return nil
+	}
+
+	tlsInfo := peer.AuthInfo.(credentials.TLSInfo)
+	for _, chains := range tlsInfo.State.VerifiedChains {
+		if len(chains) < 1 {
+			continue
+		}
+		ai = &AuthInfo{
+			Username: chains[0].Subject.CommonName,
+			Revision: as.Revision(),
+		}
+		md, ok := metadata.FromIncomingContext(ctx)
+		if !ok {
+			return nil
+		}
+
+		// gRPC-gateway proxy request to etcd server includes Grpcgateway-Accept
+		// header. The proxy uses etcd client server certificate. If the certificate
+		// has a CommonName we should never use this for authentication.
+		if gw := md["grpcgateway-accept"]; len(gw) > 0 {
+			if as.lg != nil {
+				as.lg.Warn(
+					"ignoring common name in gRPC-gateway proxy request",
+					zap.String("common-name", ai.Username),
+					zap.String("user-name", ai.Username),
+					zap.Uint64("revision", ai.Revision),
+				)
+			} else {
+				plog.Warningf("ignoring common name in gRPC-gateway proxy request %s", ai.Username)
+			}
+			return nil
+		}
+		if as.lg != nil {
+			as.lg.Debug(
+				"found command name",
+				zap.String("common-name", ai.Username),
+				zap.String("user-name", ai.Username),
+				zap.Uint64("revision", ai.Revision),
+			)
+		} else {
+			plog.Debugf("found common name %s", ai.Username)
+		}
+		break
+	}
+	return ai
+}
+
+func (as *authStore) AuthInfoFromCtx(ctx context.Context) (*AuthInfo, error) {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return nil, nil
+	}
+
+	//TODO(mitake|hexfusion) review unifying key names
+	ts, ok := md[rpctypes.TokenFieldNameGRPC]
+	if !ok {
+		ts, ok = md[rpctypes.TokenFieldNameSwagger]
+	}
+	if !ok {
+		return nil, nil
+	}
+
+	token := ts[0]
+	authInfo, uok := as.authInfoFromToken(ctx, token)
+	if !uok {
+		if as.lg != nil {
+			as.lg.Warn("invalid auth token", zap.String("token", token))
+		} else {
+			plog.Warningf("invalid auth token: %s", token)
+		}
+		return nil, ErrInvalidAuthToken
+	}
+
+	return authInfo, nil
+}
+
+func (as *authStore) GenTokenPrefix() (string, error) {
+	return as.tokenProvider.genTokenPrefix()
+}
+
+func decomposeOpts(lg *zap.Logger, optstr string) (string, map[string]string, error) {
+	opts := strings.Split(optstr, ",")
+	tokenType := opts[0]
+
+	typeSpecificOpts := make(map[string]string)
+	for i := 1; i < len(opts); i++ {
+		pair := strings.Split(opts[i], "=")
+
+		if len(pair) != 2 {
+			if lg != nil {
+				lg.Warn("invalid token option", zap.String("option", optstr))
+			} else {
+				plog.Errorf("invalid token specific option: %s", optstr)
+			}
+			return "", nil, ErrInvalidAuthOpts
+		}
+
+		if _, ok := typeSpecificOpts[pair[0]]; ok {
+			if lg != nil {
+				lg.Warn(
+					"invalid token option",
+					zap.String("option", optstr),
+					zap.String("duplicate-parameter", pair[0]),
+				)
+			} else {
+				plog.Errorf("invalid token specific option, duplicated parameters (%s): %s", pair[0], optstr)
+			}
+			return "", nil, ErrInvalidAuthOpts
+		}
+
+		typeSpecificOpts[pair[0]] = pair[1]
+	}
+
+	return tokenType, typeSpecificOpts, nil
+
+}
+
+// NewTokenProvider creates a new token provider.
+func NewTokenProvider(
+	lg *zap.Logger,
+	tokenOpts string,
+	indexWaiter func(uint64) <-chan struct{}) (TokenProvider, error) {
+	tokenType, typeSpecificOpts, err := decomposeOpts(lg, tokenOpts)
+	if err != nil {
+		return nil, ErrInvalidAuthOpts
+	}
+
+	switch tokenType {
+	case tokenTypeSimple:
+		if lg != nil {
+			lg.Warn("simple token is not cryptographically signed")
+		} else {
+			plog.Warningf("simple token is not cryptographically signed")
+		}
+		return newTokenProviderSimple(lg, indexWaiter), nil
+
+	case tokenTypeJWT:
+		return newTokenProviderJWT(lg, typeSpecificOpts)
+
+	case "":
+		return newTokenProviderNop()
+
+	default:
+		if lg != nil {
+			lg.Warn(
+				"unknown token type",
+				zap.String("type", tokenType),
+				zap.Error(ErrInvalidAuthOpts),
+			)
+		} else {
+			plog.Errorf("unknown token type: %s", tokenType)
+		}
+		return nil, ErrInvalidAuthOpts
+	}
+}
+
+func (as *authStore) WithRoot(ctx context.Context) context.Context {
+	if !as.IsAuthEnabled() {
+		return ctx
+	}
+
+	var ctxForAssign context.Context
+	if ts, ok := as.tokenProvider.(*tokenSimple); ok && ts != nil {
+		ctx1 := context.WithValue(ctx, AuthenticateParamIndex{}, uint64(0))
+		prefix, err := ts.genTokenPrefix()
+		if err != nil {
+			if as.lg != nil {
+				as.lg.Warn(
+					"failed to generate prefix of internally used token",
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("failed to generate prefix of internally used token")
+			}
+			return ctx
+		}
+		ctxForAssign = context.WithValue(ctx1, AuthenticateParamSimpleTokenPrefix{}, prefix)
+	} else {
+		ctxForAssign = ctx
+	}
+
+	token, err := as.tokenProvider.assign(ctxForAssign, "root", as.Revision())
+	if err != nil {
+		// this must not happen
+		if as.lg != nil {
+			as.lg.Warn(
+				"failed to assign token for lease revoking",
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to assign token for lease revoking: %s", err)
+		}
+		return ctx
+	}
+
+	mdMap := map[string]string{
+		rpctypes.TokenFieldNameGRPC: token,
+	}
+	tokenMD := metadata.New(mdMap)
+
+	// use "mdIncomingKey{}" since it's called from local etcdserver
+	return metadata.NewIncomingContext(ctx, tokenMD)
+}
+
+func (as *authStore) HasRole(user, role string) bool {
+	tx := as.be.BatchTx()
+	tx.Lock()
+	u := getUser(as.lg, tx, user)
+	tx.Unlock()
+
+	if u == nil {
+		if as.lg != nil {
+			as.lg.Warn(
+				"'has-role' requested for non-existing user",
+				zap.String("user-name", user),
+				zap.String("role-name", role),
+			)
+		} else {
+			plog.Warningf("tried to check user %s has role %s, but user %s doesn't exist", user, role, user)
+		}
+		return false
+	}
+
+	for _, r := range u.Roles {
+		if role == r {
+			return true
+		}
+	}
+	return false
+}
+
+func (as *authStore) BcryptCost() int {
+	return as.bcryptCost
+}
diff --git a/vendor/go.etcd.io/etcd/client/README.md b/vendor/go.etcd.io/etcd/client/README.md
new file mode 100644
index 0000000..521d6c0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/README.md
@@ -0,0 +1,112 @@
+# etcd/client
+
+etcd/client is the Go client library for etcd.
+
+[![GoDoc](https://godoc.org/go.etcd.io/etcd/client?status.png)](https://godoc.org/go.etcd.io/etcd/client)
+
+For full compatibility, it is recommended to vendor builds using etcd's vendored packages, using tools like `golang/dep`, as in [vendor directories](https://golang.org/cmd/go/#hdr-Vendor_Directories).
+
+## Install
+
+```bash
+go get go.etcd.io/etcd/client
+```
+
+## Usage
+
+```go
+package main
+
+import (
+	"log"
+	"time"
+	"context"
+
+	"go.etcd.io/etcd/client"
+)
+
+func main() {
+	cfg := client.Config{
+		Endpoints:               []string{"http://127.0.0.1:2379"},
+		Transport:               client.DefaultTransport,
+		// set timeout per request to fail fast when the target endpoint is unavailable
+		HeaderTimeoutPerRequest: time.Second,
+	}
+	c, err := client.New(cfg)
+	if err != nil {
+		log.Fatal(err)
+	}
+	kapi := client.NewKeysAPI(c)
+	// set "/foo" key with "bar" value
+	log.Print("Setting '/foo' key with 'bar' value")
+	resp, err := kapi.Set(context.Background(), "/foo", "bar", nil)
+	if err != nil {
+		log.Fatal(err)
+	} else {
+		// print common key info
+		log.Printf("Set is done. Metadata is %q\n", resp)
+	}
+	// get "/foo" key's value
+	log.Print("Getting '/foo' key value")
+	resp, err = kapi.Get(context.Background(), "/foo", nil)
+	if err != nil {
+		log.Fatal(err)
+	} else {
+		// print common key info
+		log.Printf("Get is done. Metadata is %q\n", resp)
+		// print value
+		log.Printf("%q key has %q value\n", resp.Node.Key, resp.Node.Value)
+	}
+}
+```
+
+## Error Handling
+
+etcd client might return three types of errors.
+
+- context error
+
+Each API call has its first parameter as `context`. A context can be canceled or have an attached deadline. If the context is canceled or reaches its deadline, the responding context error will be returned no matter what internal errors the API call has already encountered.
+
+- cluster error
+
+Each API call tries to send request to the cluster endpoints one by one until it successfully gets a response. If a requests to an endpoint fails, due to exceeding per request timeout or connection issues, the error will be added into a list of errors. If all possible endpoints fail, a cluster error that includes all encountered errors will be returned.
+
+- response error
+
+If the response gets from the cluster is invalid, a plain string error will be returned. For example, it might be a invalid JSON error.
+
+Here is the example code to handle client errors:
+
+```go
+cfg := client.Config{Endpoints: []string{"http://etcd1:2379","http://etcd2:2379","http://etcd3:2379"}}
+c, err := client.New(cfg)
+if err != nil {
+	log.Fatal(err)
+}
+
+kapi := client.NewKeysAPI(c)
+resp, err := kapi.Set(ctx, "test", "bar", nil)
+if err != nil {
+	if err == context.Canceled {
+		// ctx is canceled by another routine
+	} else if err == context.DeadlineExceeded {
+		// ctx is attached with a deadline and it exceeded
+	} else if cerr, ok := err.(*client.ClusterError); ok {
+		// process (cerr.Errors)
+	} else {
+		// bad cluster endpoints, which are not etcd servers
+	}
+}
+```
+
+
+## Caveat
+
+1. etcd/client prefers to use the same endpoint as long as the endpoint continues to work well. This saves socket resources, and improves efficiency for both client and server side. This preference doesn't remove consistency from the data consumed by the client because data replicated to each etcd member has already passed through the consensus process.
+
+2. etcd/client does round-robin rotation on other available endpoints if the preferred endpoint isn't functioning properly. For example, if the member that etcd/client connects to is hard killed, etcd/client will fail on the first attempt with the killed member, and succeed on the second attempt with another member. If it fails to talk to all available endpoints, it will return all errors happened.
+
+3. Default etcd/client cannot handle the case that the remote server is SIGSTOPed now. TCP keepalive mechanism doesn't help in this scenario because operating system may still send TCP keep-alive packets. Over time we'd like to improve this functionality, but solving this issue isn't high priority because a real-life case in which a server is stopped, but the connection is kept alive, hasn't been brought to our attention.
+
+4. etcd/client cannot detect whether a member is healthy with watches and non-quorum read requests. If the member is isolated from the cluster, etcd/client may retrieve outdated data. Instead, users can either issue quorum read requests or monitor the /health endpoint for member health information.
diff --git a/vendor/go.etcd.io/etcd/client/auth_role.go b/vendor/go.etcd.io/etcd/client/auth_role.go
new file mode 100644
index 0000000..b6ba7e1
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/auth_role.go
@@ -0,0 +1,236 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+)
+
+type Role struct {
+	Role        string       `json:"role"`
+	Permissions Permissions  `json:"permissions"`
+	Grant       *Permissions `json:"grant,omitempty"`
+	Revoke      *Permissions `json:"revoke,omitempty"`
+}
+
+type Permissions struct {
+	KV rwPermission `json:"kv"`
+}
+
+type rwPermission struct {
+	Read  []string `json:"read"`
+	Write []string `json:"write"`
+}
+
+type PermissionType int
+
+const (
+	ReadPermission PermissionType = iota
+	WritePermission
+	ReadWritePermission
+)
+
+// NewAuthRoleAPI constructs a new AuthRoleAPI that uses HTTP to
+// interact with etcd's role creation and modification features.
+func NewAuthRoleAPI(c Client) AuthRoleAPI {
+	return &httpAuthRoleAPI{
+		client: c,
+	}
+}
+
+type AuthRoleAPI interface {
+	// AddRole adds a role.
+	AddRole(ctx context.Context, role string) error
+
+	// RemoveRole removes a role.
+	RemoveRole(ctx context.Context, role string) error
+
+	// GetRole retrieves role details.
+	GetRole(ctx context.Context, role string) (*Role, error)
+
+	// GrantRoleKV grants a role some permission prefixes for the KV store.
+	GrantRoleKV(ctx context.Context, role string, prefixes []string, permType PermissionType) (*Role, error)
+
+	// RevokeRoleKV revokes some permission prefixes for a role on the KV store.
+	RevokeRoleKV(ctx context.Context, role string, prefixes []string, permType PermissionType) (*Role, error)
+
+	// ListRoles lists roles.
+	ListRoles(ctx context.Context) ([]string, error)
+}
+
+type httpAuthRoleAPI struct {
+	client httpClient
+}
+
+type authRoleAPIAction struct {
+	verb string
+	name string
+	role *Role
+}
+
+type authRoleAPIList struct{}
+
+func (list *authRoleAPIList) HTTPRequest(ep url.URL) *http.Request {
+	u := v2AuthURL(ep, "roles", "")
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+func (l *authRoleAPIAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2AuthURL(ep, "roles", l.name)
+	if l.role == nil {
+		req, _ := http.NewRequest(l.verb, u.String(), nil)
+		return req
+	}
+	b, err := json.Marshal(l.role)
+	if err != nil {
+		panic(err)
+	}
+	body := bytes.NewReader(b)
+	req, _ := http.NewRequest(l.verb, u.String(), body)
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+func (r *httpAuthRoleAPI) ListRoles(ctx context.Context) ([]string, error) {
+	resp, body, err := r.client.Do(ctx, &authRoleAPIList{})
+	if err != nil {
+		return nil, err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		return nil, err
+	}
+	var roleList struct {
+		Roles []Role `json:"roles"`
+	}
+	if err = json.Unmarshal(body, &roleList); err != nil {
+		return nil, err
+	}
+	ret := make([]string, 0, len(roleList.Roles))
+	for _, r := range roleList.Roles {
+		ret = append(ret, r.Role)
+	}
+	return ret, nil
+}
+
+func (r *httpAuthRoleAPI) AddRole(ctx context.Context, rolename string) error {
+	role := &Role{
+		Role: rolename,
+	}
+	return r.addRemoveRole(ctx, &authRoleAPIAction{
+		verb: "PUT",
+		name: rolename,
+		role: role,
+	})
+}
+
+func (r *httpAuthRoleAPI) RemoveRole(ctx context.Context, rolename string) error {
+	return r.addRemoveRole(ctx, &authRoleAPIAction{
+		verb: "DELETE",
+		name: rolename,
+	})
+}
+
+func (r *httpAuthRoleAPI) addRemoveRole(ctx context.Context, req *authRoleAPIAction) error {
+	resp, body, err := r.client.Do(ctx, req)
+	if err != nil {
+		return err
+	}
+	if err := assertStatusCode(resp.StatusCode, http.StatusOK, http.StatusCreated); err != nil {
+		var sec authError
+		err := json.Unmarshal(body, &sec)
+		if err != nil {
+			return err
+		}
+		return sec
+	}
+	return nil
+}
+
+func (r *httpAuthRoleAPI) GetRole(ctx context.Context, rolename string) (*Role, error) {
+	return r.modRole(ctx, &authRoleAPIAction{
+		verb: "GET",
+		name: rolename,
+	})
+}
+
+func buildRWPermission(prefixes []string, permType PermissionType) rwPermission {
+	var out rwPermission
+	switch permType {
+	case ReadPermission:
+		out.Read = prefixes
+	case WritePermission:
+		out.Write = prefixes
+	case ReadWritePermission:
+		out.Read = prefixes
+		out.Write = prefixes
+	}
+	return out
+}
+
+func (r *httpAuthRoleAPI) GrantRoleKV(ctx context.Context, rolename string, prefixes []string, permType PermissionType) (*Role, error) {
+	rwp := buildRWPermission(prefixes, permType)
+	role := &Role{
+		Role: rolename,
+		Grant: &Permissions{
+			KV: rwp,
+		},
+	}
+	return r.modRole(ctx, &authRoleAPIAction{
+		verb: "PUT",
+		name: rolename,
+		role: role,
+	})
+}
+
+func (r *httpAuthRoleAPI) RevokeRoleKV(ctx context.Context, rolename string, prefixes []string, permType PermissionType) (*Role, error) {
+	rwp := buildRWPermission(prefixes, permType)
+	role := &Role{
+		Role: rolename,
+		Revoke: &Permissions{
+			KV: rwp,
+		},
+	}
+	return r.modRole(ctx, &authRoleAPIAction{
+		verb: "PUT",
+		name: rolename,
+		role: role,
+	})
+}
+
+func (r *httpAuthRoleAPI) modRole(ctx context.Context, req *authRoleAPIAction) (*Role, error) {
+	resp, body, err := r.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		var sec authError
+		err = json.Unmarshal(body, &sec)
+		if err != nil {
+			return nil, err
+		}
+		return nil, sec
+	}
+	var role Role
+	if err = json.Unmarshal(body, &role); err != nil {
+		return nil, err
+	}
+	return &role, nil
+}
diff --git a/vendor/go.etcd.io/etcd/client/auth_user.go b/vendor/go.etcd.io/etcd/client/auth_user.go
new file mode 100644
index 0000000..8e7e2ef
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/auth_user.go
@@ -0,0 +1,319 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+	"path"
+)
+
+var (
+	defaultV2AuthPrefix = "/v2/auth"
+)
+
+type User struct {
+	User     string   `json:"user"`
+	Password string   `json:"password,omitempty"`
+	Roles    []string `json:"roles"`
+	Grant    []string `json:"grant,omitempty"`
+	Revoke   []string `json:"revoke,omitempty"`
+}
+
+// userListEntry is the user representation given by the server for ListUsers
+type userListEntry struct {
+	User  string `json:"user"`
+	Roles []Role `json:"roles"`
+}
+
+type UserRoles struct {
+	User  string `json:"user"`
+	Roles []Role `json:"roles"`
+}
+
+func v2AuthURL(ep url.URL, action string, name string) *url.URL {
+	if name != "" {
+		ep.Path = path.Join(ep.Path, defaultV2AuthPrefix, action, name)
+		return &ep
+	}
+	ep.Path = path.Join(ep.Path, defaultV2AuthPrefix, action)
+	return &ep
+}
+
+// NewAuthAPI constructs a new AuthAPI that uses HTTP to
+// interact with etcd's general auth features.
+func NewAuthAPI(c Client) AuthAPI {
+	return &httpAuthAPI{
+		client: c,
+	}
+}
+
+type AuthAPI interface {
+	// Enable auth.
+	Enable(ctx context.Context) error
+
+	// Disable auth.
+	Disable(ctx context.Context) error
+}
+
+type httpAuthAPI struct {
+	client httpClient
+}
+
+func (s *httpAuthAPI) Enable(ctx context.Context) error {
+	return s.enableDisable(ctx, &authAPIAction{"PUT"})
+}
+
+func (s *httpAuthAPI) Disable(ctx context.Context) error {
+	return s.enableDisable(ctx, &authAPIAction{"DELETE"})
+}
+
+func (s *httpAuthAPI) enableDisable(ctx context.Context, req httpAction) error {
+	resp, body, err := s.client.Do(ctx, req)
+	if err != nil {
+		return err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK, http.StatusCreated); err != nil {
+		var sec authError
+		err = json.Unmarshal(body, &sec)
+		if err != nil {
+			return err
+		}
+		return sec
+	}
+	return nil
+}
+
+type authAPIAction struct {
+	verb string
+}
+
+func (l *authAPIAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2AuthURL(ep, "enable", "")
+	req, _ := http.NewRequest(l.verb, u.String(), nil)
+	return req
+}
+
+type authError struct {
+	Message string `json:"message"`
+	Code    int    `json:"-"`
+}
+
+func (e authError) Error() string {
+	return e.Message
+}
+
+// NewAuthUserAPI constructs a new AuthUserAPI that uses HTTP to
+// interact with etcd's user creation and modification features.
+func NewAuthUserAPI(c Client) AuthUserAPI {
+	return &httpAuthUserAPI{
+		client: c,
+	}
+}
+
+type AuthUserAPI interface {
+	// AddUser adds a user.
+	AddUser(ctx context.Context, username string, password string) error
+
+	// RemoveUser removes a user.
+	RemoveUser(ctx context.Context, username string) error
+
+	// GetUser retrieves user details.
+	GetUser(ctx context.Context, username string) (*User, error)
+
+	// GrantUser grants a user some permission roles.
+	GrantUser(ctx context.Context, username string, roles []string) (*User, error)
+
+	// RevokeUser revokes some permission roles from a user.
+	RevokeUser(ctx context.Context, username string, roles []string) (*User, error)
+
+	// ChangePassword changes the user's password.
+	ChangePassword(ctx context.Context, username string, password string) (*User, error)
+
+	// ListUsers lists the users.
+	ListUsers(ctx context.Context) ([]string, error)
+}
+
+type httpAuthUserAPI struct {
+	client httpClient
+}
+
+type authUserAPIAction struct {
+	verb     string
+	username string
+	user     *User
+}
+
+type authUserAPIList struct{}
+
+func (list *authUserAPIList) HTTPRequest(ep url.URL) *http.Request {
+	u := v2AuthURL(ep, "users", "")
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+func (l *authUserAPIAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2AuthURL(ep, "users", l.username)
+	if l.user == nil {
+		req, _ := http.NewRequest(l.verb, u.String(), nil)
+		return req
+	}
+	b, err := json.Marshal(l.user)
+	if err != nil {
+		panic(err)
+	}
+	body := bytes.NewReader(b)
+	req, _ := http.NewRequest(l.verb, u.String(), body)
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+func (u *httpAuthUserAPI) ListUsers(ctx context.Context) ([]string, error) {
+	resp, body, err := u.client.Do(ctx, &authUserAPIList{})
+	if err != nil {
+		return nil, err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		var sec authError
+		err = json.Unmarshal(body, &sec)
+		if err != nil {
+			return nil, err
+		}
+		return nil, sec
+	}
+
+	var userList struct {
+		Users []userListEntry `json:"users"`
+	}
+
+	if err = json.Unmarshal(body, &userList); err != nil {
+		return nil, err
+	}
+
+	ret := make([]string, 0, len(userList.Users))
+	for _, u := range userList.Users {
+		ret = append(ret, u.User)
+	}
+	return ret, nil
+}
+
+func (u *httpAuthUserAPI) AddUser(ctx context.Context, username string, password string) error {
+	user := &User{
+		User:     username,
+		Password: password,
+	}
+	return u.addRemoveUser(ctx, &authUserAPIAction{
+		verb:     "PUT",
+		username: username,
+		user:     user,
+	})
+}
+
+func (u *httpAuthUserAPI) RemoveUser(ctx context.Context, username string) error {
+	return u.addRemoveUser(ctx, &authUserAPIAction{
+		verb:     "DELETE",
+		username: username,
+	})
+}
+
+func (u *httpAuthUserAPI) addRemoveUser(ctx context.Context, req *authUserAPIAction) error {
+	resp, body, err := u.client.Do(ctx, req)
+	if err != nil {
+		return err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK, http.StatusCreated); err != nil {
+		var sec authError
+		err = json.Unmarshal(body, &sec)
+		if err != nil {
+			return err
+		}
+		return sec
+	}
+	return nil
+}
+
+func (u *httpAuthUserAPI) GetUser(ctx context.Context, username string) (*User, error) {
+	return u.modUser(ctx, &authUserAPIAction{
+		verb:     "GET",
+		username: username,
+	})
+}
+
+func (u *httpAuthUserAPI) GrantUser(ctx context.Context, username string, roles []string) (*User, error) {
+	user := &User{
+		User:  username,
+		Grant: roles,
+	}
+	return u.modUser(ctx, &authUserAPIAction{
+		verb:     "PUT",
+		username: username,
+		user:     user,
+	})
+}
+
+func (u *httpAuthUserAPI) RevokeUser(ctx context.Context, username string, roles []string) (*User, error) {
+	user := &User{
+		User:   username,
+		Revoke: roles,
+	}
+	return u.modUser(ctx, &authUserAPIAction{
+		verb:     "PUT",
+		username: username,
+		user:     user,
+	})
+}
+
+func (u *httpAuthUserAPI) ChangePassword(ctx context.Context, username string, password string) (*User, error) {
+	user := &User{
+		User:     username,
+		Password: password,
+	}
+	return u.modUser(ctx, &authUserAPIAction{
+		verb:     "PUT",
+		username: username,
+		user:     user,
+	})
+}
+
+func (u *httpAuthUserAPI) modUser(ctx context.Context, req *authUserAPIAction) (*User, error) {
+	resp, body, err := u.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+	if err = assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		var sec authError
+		err = json.Unmarshal(body, &sec)
+		if err != nil {
+			return nil, err
+		}
+		return nil, sec
+	}
+	var user User
+	if err = json.Unmarshal(body, &user); err != nil {
+		var userR UserRoles
+		if urerr := json.Unmarshal(body, &userR); urerr != nil {
+			return nil, err
+		}
+		user.User = userR.User
+		for _, r := range userR.Roles {
+			user.Roles = append(user.Roles, r.Role)
+		}
+	}
+	return &user, nil
+}
diff --git a/vendor/go.etcd.io/etcd/client/cancelreq.go b/vendor/go.etcd.io/etcd/client/cancelreq.go
new file mode 100644
index 0000000..76d1f04
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/cancelreq.go
@@ -0,0 +1,18 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// borrowed from golang/net/context/ctxhttp/cancelreq.go
+
+package client
+
+import "net/http"
+
+func requestCanceler(tr CancelableTransport, req *http.Request) func() {
+	ch := make(chan struct{})
+	req.Cancel = ch
+
+	return func() {
+		close(ch)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/client/client.go b/vendor/go.etcd.io/etcd/client/client.go
new file mode 100644
index 0000000..de9ab79
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/client.go
@@ -0,0 +1,710 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"net/http"
+	"net/url"
+	"sort"
+	"strconv"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/version"
+)
+
+var (
+	ErrNoEndpoints           = errors.New("client: no endpoints available")
+	ErrTooManyRedirects      = errors.New("client: too many redirects")
+	ErrClusterUnavailable    = errors.New("client: etcd cluster is unavailable or misconfigured")
+	ErrNoLeaderEndpoint      = errors.New("client: no leader endpoint available")
+	errTooManyRedirectChecks = errors.New("client: too many redirect checks")
+
+	// oneShotCtxValue is set on a context using WithValue(&oneShotValue) so
+	// that Do() will not retry a request
+	oneShotCtxValue interface{}
+)
+
+var DefaultRequestTimeout = 5 * time.Second
+
+var DefaultTransport CancelableTransport = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
+	Dial: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).Dial,
+	TLSHandshakeTimeout: 10 * time.Second,
+}
+
+type EndpointSelectionMode int
+
+const (
+	// EndpointSelectionRandom is the default value of the 'SelectionMode'.
+	// As the name implies, the client object will pick a node from the members
+	// of the cluster in a random fashion. If the cluster has three members, A, B,
+	// and C, the client picks any node from its three members as its request
+	// destination.
+	EndpointSelectionRandom EndpointSelectionMode = iota
+
+	// If 'SelectionMode' is set to 'EndpointSelectionPrioritizeLeader',
+	// requests are sent directly to the cluster leader. This reduces
+	// forwarding roundtrips compared to making requests to etcd followers
+	// who then forward them to the cluster leader. In the event of a leader
+	// failure, however, clients configured this way cannot prioritize among
+	// the remaining etcd followers. Therefore, when a client sets 'SelectionMode'
+	// to 'EndpointSelectionPrioritizeLeader', it must use 'client.AutoSync()' to
+	// maintain its knowledge of current cluster state.
+	//
+	// This mode should be used with Client.AutoSync().
+	EndpointSelectionPrioritizeLeader
+)
+
+type Config struct {
+	// Endpoints defines a set of URLs (schemes, hosts and ports only)
+	// that can be used to communicate with a logical etcd cluster. For
+	// example, a three-node cluster could be provided like so:
+	//
+	// 	Endpoints: []string{
+	//		"http://node1.example.com:2379",
+	//		"http://node2.example.com:2379",
+	//		"http://node3.example.com:2379",
+	//	}
+	//
+	// If multiple endpoints are provided, the Client will attempt to
+	// use them all in the event that one or more of them are unusable.
+	//
+	// If Client.Sync is ever called, the Client may cache an alternate
+	// set of endpoints to continue operation.
+	Endpoints []string
+
+	// Transport is used by the Client to drive HTTP requests. If not
+	// provided, DefaultTransport will be used.
+	Transport CancelableTransport
+
+	// CheckRedirect specifies the policy for handling HTTP redirects.
+	// If CheckRedirect is not nil, the Client calls it before
+	// following an HTTP redirect. The sole argument is the number of
+	// requests that have already been made. If CheckRedirect returns
+	// an error, Client.Do will not make any further requests and return
+	// the error back it to the caller.
+	//
+	// If CheckRedirect is nil, the Client uses its default policy,
+	// which is to stop after 10 consecutive requests.
+	CheckRedirect CheckRedirectFunc
+
+	// Username specifies the user credential to add as an authorization header
+	Username string
+
+	// Password is the password for the specified user to add as an authorization header
+	// to the request.
+	Password string
+
+	// HeaderTimeoutPerRequest specifies the time limit to wait for response
+	// header in a single request made by the Client. The timeout includes
+	// connection time, any redirects, and header wait time.
+	//
+	// For non-watch GET request, server returns the response body immediately.
+	// For PUT/POST/DELETE request, server will attempt to commit request
+	// before responding, which is expected to take `100ms + 2 * RTT`.
+	// For watch request, server returns the header immediately to notify Client
+	// watch start. But if server is behind some kind of proxy, the response
+	// header may be cached at proxy, and Client cannot rely on this behavior.
+	//
+	// Especially, wait request will ignore this timeout.
+	//
+	// One API call may send multiple requests to different etcd servers until it
+	// succeeds. Use context of the API to specify the overall timeout.
+	//
+	// A HeaderTimeoutPerRequest of zero means no timeout.
+	HeaderTimeoutPerRequest time.Duration
+
+	// SelectionMode is an EndpointSelectionMode enum that specifies the
+	// policy for choosing the etcd cluster node to which requests are sent.
+	SelectionMode EndpointSelectionMode
+}
+
+func (cfg *Config) transport() CancelableTransport {
+	if cfg.Transport == nil {
+		return DefaultTransport
+	}
+	return cfg.Transport
+}
+
+func (cfg *Config) checkRedirect() CheckRedirectFunc {
+	if cfg.CheckRedirect == nil {
+		return DefaultCheckRedirect
+	}
+	return cfg.CheckRedirect
+}
+
+// CancelableTransport mimics net/http.Transport, but requires that
+// the object also support request cancellation.
+type CancelableTransport interface {
+	http.RoundTripper
+	CancelRequest(req *http.Request)
+}
+
+type CheckRedirectFunc func(via int) error
+
+// DefaultCheckRedirect follows up to 10 redirects, but no more.
+var DefaultCheckRedirect CheckRedirectFunc = func(via int) error {
+	if via > 10 {
+		return ErrTooManyRedirects
+	}
+	return nil
+}
+
+type Client interface {
+	// Sync updates the internal cache of the etcd cluster's membership.
+	Sync(context.Context) error
+
+	// AutoSync periodically calls Sync() every given interval.
+	// The recommended sync interval is 10 seconds to 1 minute, which does
+	// not bring too much overhead to server and makes client catch up the
+	// cluster change in time.
+	//
+	// The example to use it:
+	//
+	//  for {
+	//      err := client.AutoSync(ctx, 10*time.Second)
+	//      if err == context.DeadlineExceeded || err == context.Canceled {
+	//          break
+	//      }
+	//      log.Print(err)
+	//  }
+	AutoSync(context.Context, time.Duration) error
+
+	// Endpoints returns a copy of the current set of API endpoints used
+	// by Client to resolve HTTP requests. If Sync has ever been called,
+	// this may differ from the initial Endpoints provided in the Config.
+	Endpoints() []string
+
+	// SetEndpoints sets the set of API endpoints used by Client to resolve
+	// HTTP requests. If the given endpoints are not valid, an error will be
+	// returned
+	SetEndpoints(eps []string) error
+
+	// GetVersion retrieves the current etcd server and cluster version
+	GetVersion(ctx context.Context) (*version.Versions, error)
+
+	httpClient
+}
+
+func New(cfg Config) (Client, error) {
+	c := &httpClusterClient{
+		clientFactory: newHTTPClientFactory(cfg.transport(), cfg.checkRedirect(), cfg.HeaderTimeoutPerRequest),
+		rand:          rand.New(rand.NewSource(int64(time.Now().Nanosecond()))),
+		selectionMode: cfg.SelectionMode,
+	}
+	if cfg.Username != "" {
+		c.credentials = &credentials{
+			username: cfg.Username,
+			password: cfg.Password,
+		}
+	}
+	if err := c.SetEndpoints(cfg.Endpoints); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+type httpClient interface {
+	Do(context.Context, httpAction) (*http.Response, []byte, error)
+}
+
+func newHTTPClientFactory(tr CancelableTransport, cr CheckRedirectFunc, headerTimeout time.Duration) httpClientFactory {
+	return func(ep url.URL) httpClient {
+		return &redirectFollowingHTTPClient{
+			checkRedirect: cr,
+			client: &simpleHTTPClient{
+				transport:     tr,
+				endpoint:      ep,
+				headerTimeout: headerTimeout,
+			},
+		}
+	}
+}
+
+type credentials struct {
+	username string
+	password string
+}
+
+type httpClientFactory func(url.URL) httpClient
+
+type httpAction interface {
+	HTTPRequest(url.URL) *http.Request
+}
+
+type httpClusterClient struct {
+	clientFactory httpClientFactory
+	endpoints     []url.URL
+	pinned        int
+	credentials   *credentials
+	sync.RWMutex
+	rand          *rand.Rand
+	selectionMode EndpointSelectionMode
+}
+
+func (c *httpClusterClient) getLeaderEndpoint(ctx context.Context, eps []url.URL) (string, error) {
+	ceps := make([]url.URL, len(eps))
+	copy(ceps, eps)
+
+	// To perform a lookup on the new endpoint list without using the current
+	// client, we'll copy it
+	clientCopy := &httpClusterClient{
+		clientFactory: c.clientFactory,
+		credentials:   c.credentials,
+		rand:          c.rand,
+
+		pinned:    0,
+		endpoints: ceps,
+	}
+
+	mAPI := NewMembersAPI(clientCopy)
+	leader, err := mAPI.Leader(ctx)
+	if err != nil {
+		return "", err
+	}
+	if len(leader.ClientURLs) == 0 {
+		return "", ErrNoLeaderEndpoint
+	}
+
+	return leader.ClientURLs[0], nil // TODO: how to handle multiple client URLs?
+}
+
+func (c *httpClusterClient) parseEndpoints(eps []string) ([]url.URL, error) {
+	if len(eps) == 0 {
+		return []url.URL{}, ErrNoEndpoints
+	}
+
+	neps := make([]url.URL, len(eps))
+	for i, ep := range eps {
+		u, err := url.Parse(ep)
+		if err != nil {
+			return []url.URL{}, err
+		}
+		neps[i] = *u
+	}
+	return neps, nil
+}
+
+func (c *httpClusterClient) SetEndpoints(eps []string) error {
+	neps, err := c.parseEndpoints(eps)
+	if err != nil {
+		return err
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	c.endpoints = shuffleEndpoints(c.rand, neps)
+	// We're not doing anything for PrioritizeLeader here. This is
+	// due to not having a context meaning we can't call getLeaderEndpoint
+	// However, if you're using PrioritizeLeader, you've already been told
+	// to regularly call sync, where we do have a ctx, and can figure the
+	// leader. PrioritizeLeader is also quite a loose guarantee, so deal
+	// with it
+	c.pinned = 0
+
+	return nil
+}
+
+func (c *httpClusterClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
+	action := act
+	c.RLock()
+	leps := len(c.endpoints)
+	eps := make([]url.URL, leps)
+	n := copy(eps, c.endpoints)
+	pinned := c.pinned
+
+	if c.credentials != nil {
+		action = &authedAction{
+			act:         act,
+			credentials: *c.credentials,
+		}
+	}
+	c.RUnlock()
+
+	if leps == 0 {
+		return nil, nil, ErrNoEndpoints
+	}
+
+	if leps != n {
+		return nil, nil, errors.New("unable to pick endpoint: copy failed")
+	}
+
+	var resp *http.Response
+	var body []byte
+	var err error
+	cerr := &ClusterError{}
+	isOneShot := ctx.Value(&oneShotCtxValue) != nil
+
+	for i := pinned; i < leps+pinned; i++ {
+		k := i % leps
+		hc := c.clientFactory(eps[k])
+		resp, body, err = hc.Do(ctx, action)
+		if err != nil {
+			cerr.Errors = append(cerr.Errors, err)
+			if err == ctx.Err() {
+				return nil, nil, ctx.Err()
+			}
+			if err == context.Canceled || err == context.DeadlineExceeded {
+				return nil, nil, err
+			}
+		} else if resp.StatusCode/100 == 5 {
+			switch resp.StatusCode {
+			case http.StatusInternalServerError, http.StatusServiceUnavailable:
+				// TODO: make sure this is a no leader response
+				cerr.Errors = append(cerr.Errors, fmt.Errorf("client: etcd member %s has no leader", eps[k].String()))
+			default:
+				cerr.Errors = append(cerr.Errors, fmt.Errorf("client: etcd member %s returns server error [%s]", eps[k].String(), http.StatusText(resp.StatusCode)))
+			}
+			err = cerr.Errors[0]
+		}
+		if err != nil {
+			if !isOneShot {
+				continue
+			}
+			c.Lock()
+			c.pinned = (k + 1) % leps
+			c.Unlock()
+			return nil, nil, err
+		}
+		if k != pinned {
+			c.Lock()
+			c.pinned = k
+			c.Unlock()
+		}
+		return resp, body, nil
+	}
+
+	return nil, nil, cerr
+}
+
+func (c *httpClusterClient) Endpoints() []string {
+	c.RLock()
+	defer c.RUnlock()
+
+	eps := make([]string, len(c.endpoints))
+	for i, ep := range c.endpoints {
+		eps[i] = ep.String()
+	}
+
+	return eps
+}
+
+func (c *httpClusterClient) Sync(ctx context.Context) error {
+	mAPI := NewMembersAPI(c)
+	ms, err := mAPI.List(ctx)
+	if err != nil {
+		return err
+	}
+
+	var eps []string
+	for _, m := range ms {
+		eps = append(eps, m.ClientURLs...)
+	}
+
+	neps, err := c.parseEndpoints(eps)
+	if err != nil {
+		return err
+	}
+
+	npin := 0
+
+	switch c.selectionMode {
+	case EndpointSelectionRandom:
+		c.RLock()
+		eq := endpointsEqual(c.endpoints, neps)
+		c.RUnlock()
+
+		if eq {
+			return nil
+		}
+		// When items in the endpoint list changes, we choose a new pin
+		neps = shuffleEndpoints(c.rand, neps)
+	case EndpointSelectionPrioritizeLeader:
+		nle, err := c.getLeaderEndpoint(ctx, neps)
+		if err != nil {
+			return ErrNoLeaderEndpoint
+		}
+
+		for i, n := range neps {
+			if n.String() == nle {
+				npin = i
+				break
+			}
+		}
+	default:
+		return fmt.Errorf("invalid endpoint selection mode: %d", c.selectionMode)
+	}
+
+	c.Lock()
+	defer c.Unlock()
+	c.endpoints = neps
+	c.pinned = npin
+
+	return nil
+}
+
+func (c *httpClusterClient) AutoSync(ctx context.Context, interval time.Duration) error {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+	for {
+		err := c.Sync(ctx)
+		if err != nil {
+			return err
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-ticker.C:
+		}
+	}
+}
+
+func (c *httpClusterClient) GetVersion(ctx context.Context) (*version.Versions, error) {
+	act := &getAction{Prefix: "/version"}
+
+	resp, body, err := c.Do(ctx, act)
+	if err != nil {
+		return nil, err
+	}
+
+	switch resp.StatusCode {
+	case http.StatusOK:
+		if len(body) == 0 {
+			return nil, ErrEmptyBody
+		}
+		var vresp version.Versions
+		if err := json.Unmarshal(body, &vresp); err != nil {
+			return nil, ErrInvalidJSON
+		}
+		return &vresp, nil
+	default:
+		var etcdErr Error
+		if err := json.Unmarshal(body, &etcdErr); err != nil {
+			return nil, ErrInvalidJSON
+		}
+		return nil, etcdErr
+	}
+}
+
+type roundTripResponse struct {
+	resp *http.Response
+	err  error
+}
+
+type simpleHTTPClient struct {
+	transport     CancelableTransport
+	endpoint      url.URL
+	headerTimeout time.Duration
+}
+
+func (c *simpleHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
+	req := act.HTTPRequest(c.endpoint)
+
+	if err := printcURL(req); err != nil {
+		return nil, nil, err
+	}
+
+	isWait := false
+	if req != nil && req.URL != nil {
+		ws := req.URL.Query().Get("wait")
+		if len(ws) != 0 {
+			var err error
+			isWait, err = strconv.ParseBool(ws)
+			if err != nil {
+				return nil, nil, fmt.Errorf("wrong wait value %s (%v for %+v)", ws, err, req)
+			}
+		}
+	}
+
+	var hctx context.Context
+	var hcancel context.CancelFunc
+	if !isWait && c.headerTimeout > 0 {
+		hctx, hcancel = context.WithTimeout(ctx, c.headerTimeout)
+	} else {
+		hctx, hcancel = context.WithCancel(ctx)
+	}
+	defer hcancel()
+
+	reqcancel := requestCanceler(c.transport, req)
+
+	rtchan := make(chan roundTripResponse, 1)
+	go func() {
+		resp, err := c.transport.RoundTrip(req)
+		rtchan <- roundTripResponse{resp: resp, err: err}
+		close(rtchan)
+	}()
+
+	var resp *http.Response
+	var err error
+
+	select {
+	case rtresp := <-rtchan:
+		resp, err = rtresp.resp, rtresp.err
+	case <-hctx.Done():
+		// cancel and wait for request to actually exit before continuing
+		reqcancel()
+		rtresp := <-rtchan
+		resp = rtresp.resp
+		switch {
+		case ctx.Err() != nil:
+			err = ctx.Err()
+		case hctx.Err() != nil:
+			err = fmt.Errorf("client: endpoint %s exceeded header timeout", c.endpoint.String())
+		default:
+			panic("failed to get error from context")
+		}
+	}
+
+	// always check for resp nil-ness to deal with possible
+	// race conditions between channels above
+	defer func() {
+		if resp != nil {
+			resp.Body.Close()
+		}
+	}()
+
+	if err != nil {
+		return nil, nil, err
+	}
+
+	var body []byte
+	done := make(chan struct{})
+	go func() {
+		body, err = ioutil.ReadAll(resp.Body)
+		done <- struct{}{}
+	}()
+
+	select {
+	case <-ctx.Done():
+		resp.Body.Close()
+		<-done
+		return nil, nil, ctx.Err()
+	case <-done:
+	}
+
+	return resp, body, err
+}
+
+type authedAction struct {
+	act         httpAction
+	credentials credentials
+}
+
+func (a *authedAction) HTTPRequest(url url.URL) *http.Request {
+	r := a.act.HTTPRequest(url)
+	r.SetBasicAuth(a.credentials.username, a.credentials.password)
+	return r
+}
+
+type redirectFollowingHTTPClient struct {
+	client        httpClient
+	checkRedirect CheckRedirectFunc
+}
+
+func (r *redirectFollowingHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
+	next := act
+	for i := 0; i < 100; i++ {
+		if i > 0 {
+			if err := r.checkRedirect(i); err != nil {
+				return nil, nil, err
+			}
+		}
+		resp, body, err := r.client.Do(ctx, next)
+		if err != nil {
+			return nil, nil, err
+		}
+		if resp.StatusCode/100 == 3 {
+			hdr := resp.Header.Get("Location")
+			if hdr == "" {
+				return nil, nil, fmt.Errorf("location header not set")
+			}
+			loc, err := url.Parse(hdr)
+			if err != nil {
+				return nil, nil, fmt.Errorf("location header not valid URL: %s", hdr)
+			}
+			next = &redirectedHTTPAction{
+				action:   act,
+				location: *loc,
+			}
+			continue
+		}
+		return resp, body, nil
+	}
+
+	return nil, nil, errTooManyRedirectChecks
+}
+
+type redirectedHTTPAction struct {
+	action   httpAction
+	location url.URL
+}
+
+func (r *redirectedHTTPAction) HTTPRequest(ep url.URL) *http.Request {
+	orig := r.action.HTTPRequest(ep)
+	orig.URL = &r.location
+	return orig
+}
+
+func shuffleEndpoints(r *rand.Rand, eps []url.URL) []url.URL {
+	// copied from Go 1.9<= rand.Rand.Perm
+	n := len(eps)
+	p := make([]int, n)
+	for i := 0; i < n; i++ {
+		j := r.Intn(i + 1)
+		p[i] = p[j]
+		p[j] = i
+	}
+	neps := make([]url.URL, n)
+	for i, k := range p {
+		neps[i] = eps[k]
+	}
+	return neps
+}
+
+func endpointsEqual(left, right []url.URL) bool {
+	if len(left) != len(right) {
+		return false
+	}
+
+	sLeft := make([]string, len(left))
+	sRight := make([]string, len(right))
+	for i, l := range left {
+		sLeft[i] = l.String()
+	}
+	for i, r := range right {
+		sRight[i] = r.String()
+	}
+
+	sort.Strings(sLeft)
+	sort.Strings(sRight)
+	for i := range sLeft {
+		if sLeft[i] != sRight[i] {
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/go.etcd.io/etcd/client/cluster_error.go b/vendor/go.etcd.io/etcd/client/cluster_error.go
new file mode 100644
index 0000000..34618cd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/cluster_error.go
@@ -0,0 +1,37 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import "fmt"
+
+type ClusterError struct {
+	Errors []error
+}
+
+func (ce *ClusterError) Error() string {
+	s := ErrClusterUnavailable.Error()
+	for i, e := range ce.Errors {
+		s += fmt.Sprintf("; error #%d: %s\n", i, e)
+	}
+	return s
+}
+
+func (ce *ClusterError) Detail() string {
+	s := ""
+	for i, e := range ce.Errors {
+		s += fmt.Sprintf("error #%d: %s\n", i, e)
+	}
+	return s
+}
diff --git a/vendor/go.etcd.io/etcd/client/curl.go b/vendor/go.etcd.io/etcd/client/curl.go
new file mode 100644
index 0000000..c8bc9fb
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/curl.go
@@ -0,0 +1,70 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+)
+
+var (
+	cURLDebug = false
+)
+
+func EnablecURLDebug() {
+	cURLDebug = true
+}
+
+func DisablecURLDebug() {
+	cURLDebug = false
+}
+
+// printcURL prints the cURL equivalent request to stderr.
+// It returns an error if the body of the request cannot
+// be read.
+// The caller MUST cancel the request if there is an error.
+func printcURL(req *http.Request) error {
+	if !cURLDebug {
+		return nil
+	}
+	var (
+		command string
+		b       []byte
+		err     error
+	)
+
+	if req.URL != nil {
+		command = fmt.Sprintf("curl -X %s %s", req.Method, req.URL.String())
+	}
+
+	if req.Body != nil {
+		b, err = ioutil.ReadAll(req.Body)
+		if err != nil {
+			return err
+		}
+		command += fmt.Sprintf(" -d %q", string(b))
+	}
+
+	fmt.Fprintf(os.Stderr, "cURL Command: %s\n", command)
+
+	// reset body
+	body := bytes.NewBuffer(b)
+	req.Body = ioutil.NopCloser(body)
+
+	return nil
+}
diff --git a/vendor/go.etcd.io/etcd/client/discover.go b/vendor/go.etcd.io/etcd/client/discover.go
new file mode 100644
index 0000000..580c256
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/discover.go
@@ -0,0 +1,40 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"go.etcd.io/etcd/pkg/srv"
+)
+
+// Discoverer is an interface that wraps the Discover method.
+type Discoverer interface {
+	// Discover looks up the etcd servers for the domain.
+	Discover(domain string, serviceName string) ([]string, error)
+}
+
+type srvDiscover struct{}
+
+// NewSRVDiscover constructs a new Discoverer that uses the stdlib to lookup SRV records.
+func NewSRVDiscover() Discoverer {
+	return &srvDiscover{}
+}
+
+func (d *srvDiscover) Discover(domain string, serviceName string) ([]string, error) {
+	srvs, err := srv.GetClient("etcd-client", domain, serviceName)
+	if err != nil {
+		return nil, err
+	}
+	return srvs.Endpoints, nil
+}
diff --git a/vendor/go.etcd.io/etcd/client/doc.go b/vendor/go.etcd.io/etcd/client/doc.go
new file mode 100644
index 0000000..abe5199
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/doc.go
@@ -0,0 +1,73 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package client provides bindings for the etcd APIs.
+
+Create a Config and exchange it for a Client:
+
+	import (
+		"net/http"
+		"context"
+
+		"go.etcd.io/etcd/client"
+	)
+
+	cfg := client.Config{
+		Endpoints: []string{"http://127.0.0.1:2379"},
+		Transport: DefaultTransport,
+	}
+
+	c, err := client.New(cfg)
+	if err != nil {
+		// handle error
+	}
+
+Clients are safe for concurrent use by multiple goroutines.
+
+Create a KeysAPI using the Client, then use it to interact with etcd:
+
+	kAPI := client.NewKeysAPI(c)
+
+	// create a new key /foo with the value "bar"
+	_, err = kAPI.Create(context.Background(), "/foo", "bar")
+	if err != nil {
+		// handle error
+	}
+
+	// delete the newly created key only if the value is still "bar"
+	_, err = kAPI.Delete(context.Background(), "/foo", &DeleteOptions{PrevValue: "bar"})
+	if err != nil {
+		// handle error
+	}
+
+Use a custom context to set timeouts on your operations:
+
+	import "time"
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	// set a new key, ignoring its previous state
+	_, err := kAPI.Set(ctx, "/ping", "pong", nil)
+	if err != nil {
+		if err == context.DeadlineExceeded {
+			// request took longer than 5s
+		} else {
+			// handle error
+		}
+	}
+
+*/
+package client
diff --git a/vendor/go.etcd.io/etcd/client/json.go b/vendor/go.etcd.io/etcd/client/json.go
new file mode 100644
index 0000000..97cdbcd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/json.go
@@ -0,0 +1,72 @@
+// Copyright 2019 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"github.com/json-iterator/go"
+	"github.com/modern-go/reflect2"
+	"strconv"
+	"unsafe"
+)
+
+type customNumberExtension struct {
+	jsoniter.DummyExtension
+}
+
+func (cne *customNumberExtension) CreateDecoder(typ reflect2.Type) jsoniter.ValDecoder {
+	if typ.String() == "interface {}" {
+		return customNumberDecoder{}
+	}
+	return nil
+}
+
+type customNumberDecoder struct {
+}
+
+func (customNumberDecoder) Decode(ptr unsafe.Pointer, iter *jsoniter.Iterator) {
+	switch iter.WhatIsNext() {
+	case jsoniter.NumberValue:
+		var number jsoniter.Number
+		iter.ReadVal(&number)
+		i64, err := strconv.ParseInt(string(number), 10, 64)
+		if err == nil {
+			*(*interface{})(ptr) = i64
+			return
+		}
+		f64, err := strconv.ParseFloat(string(number), 64)
+		if err == nil {
+			*(*interface{})(ptr) = f64
+			return
+		}
+		iter.ReportError("DecodeNumber", err.Error())
+	default:
+		*(*interface{})(ptr) = iter.Read()
+	}
+}
+
+// caseSensitiveJsonIterator returns a jsoniterator API that's configured to be
+// case-sensitive when unmarshalling, and otherwise compatible with
+// the encoding/json standard library.
+func caseSensitiveJsonIterator() jsoniter.API {
+	config := jsoniter.Config{
+		EscapeHTML:             true,
+		SortMapKeys:            true,
+		ValidateJsonRawMessage: true,
+		CaseSensitive:          true,
+	}.Froze()
+	// Force jsoniter to decode number to interface{} via int64/float64, if possible.
+	config.RegisterExtension(&customNumberExtension{})
+	return config
+}
diff --git a/vendor/go.etcd.io/etcd/client/keys.go b/vendor/go.etcd.io/etcd/client/keys.go
new file mode 100644
index 0000000..ec53830
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/keys.go
@@ -0,0 +1,679 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go.etcd.io/etcd/pkg/pathutil"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	ErrorCodeKeyNotFound  = 100
+	ErrorCodeTestFailed   = 101
+	ErrorCodeNotFile      = 102
+	ErrorCodeNotDir       = 104
+	ErrorCodeNodeExist    = 105
+	ErrorCodeRootROnly    = 107
+	ErrorCodeDirNotEmpty  = 108
+	ErrorCodeUnauthorized = 110
+
+	ErrorCodePrevValueRequired = 201
+	ErrorCodeTTLNaN            = 202
+	ErrorCodeIndexNaN          = 203
+	ErrorCodeInvalidField      = 209
+	ErrorCodeInvalidForm       = 210
+
+	ErrorCodeRaftInternal = 300
+	ErrorCodeLeaderElect  = 301
+
+	ErrorCodeWatcherCleared    = 400
+	ErrorCodeEventIndexCleared = 401
+)
+
+type Error struct {
+	Code    int    `json:"errorCode"`
+	Message string `json:"message"`
+	Cause   string `json:"cause"`
+	Index   uint64 `json:"index"`
+}
+
+func (e Error) Error() string {
+	return fmt.Sprintf("%v: %v (%v) [%v]", e.Code, e.Message, e.Cause, e.Index)
+}
+
+var (
+	ErrInvalidJSON = errors.New("client: response is invalid json. The endpoint is probably not valid etcd cluster endpoint")
+	ErrEmptyBody   = errors.New("client: response body is empty")
+)
+
+// PrevExistType is used to define an existence condition when setting
+// or deleting Nodes.
+type PrevExistType string
+
+const (
+	PrevIgnore  = PrevExistType("")
+	PrevExist   = PrevExistType("true")
+	PrevNoExist = PrevExistType("false")
+)
+
+var (
+	defaultV2KeysPrefix = "/v2/keys"
+)
+
+// NewKeysAPI builds a KeysAPI that interacts with etcd's key-value
+// API over HTTP.
+func NewKeysAPI(c Client) KeysAPI {
+	return NewKeysAPIWithPrefix(c, defaultV2KeysPrefix)
+}
+
+// NewKeysAPIWithPrefix acts like NewKeysAPI, but allows the caller
+// to provide a custom base URL path. This should only be used in
+// very rare cases.
+func NewKeysAPIWithPrefix(c Client, p string) KeysAPI {
+	return &httpKeysAPI{
+		client: c,
+		prefix: p,
+	}
+}
+
+type KeysAPI interface {
+	// Get retrieves a set of Nodes from etcd
+	Get(ctx context.Context, key string, opts *GetOptions) (*Response, error)
+
+	// Set assigns a new value to a Node identified by a given key. The caller
+	// may define a set of conditions in the SetOptions. If SetOptions.Dir=true
+	// then value is ignored.
+	Set(ctx context.Context, key, value string, opts *SetOptions) (*Response, error)
+
+	// Delete removes a Node identified by the given key, optionally destroying
+	// all of its children as well. The caller may define a set of required
+	// conditions in an DeleteOptions object.
+	Delete(ctx context.Context, key string, opts *DeleteOptions) (*Response, error)
+
+	// Create is an alias for Set w/ PrevExist=false
+	Create(ctx context.Context, key, value string) (*Response, error)
+
+	// CreateInOrder is used to atomically create in-order keys within the given directory.
+	CreateInOrder(ctx context.Context, dir, value string, opts *CreateInOrderOptions) (*Response, error)
+
+	// Update is an alias for Set w/ PrevExist=true
+	Update(ctx context.Context, key, value string) (*Response, error)
+
+	// Watcher builds a new Watcher targeted at a specific Node identified
+	// by the given key. The Watcher may be configured at creation time
+	// through a WatcherOptions object. The returned Watcher is designed
+	// to emit events that happen to a Node, and optionally to its children.
+	Watcher(key string, opts *WatcherOptions) Watcher
+}
+
+type WatcherOptions struct {
+	// AfterIndex defines the index after-which the Watcher should
+	// start emitting events. For example, if a value of 5 is
+	// provided, the first event will have an index >= 6.
+	//
+	// Setting AfterIndex to 0 (default) means that the Watcher
+	// should start watching for events starting at the current
+	// index, whatever that may be.
+	AfterIndex uint64
+
+	// Recursive specifies whether or not the Watcher should emit
+	// events that occur in children of the given keyspace. If set
+	// to false (default), events will be limited to those that
+	// occur for the exact key.
+	Recursive bool
+}
+
+type CreateInOrderOptions struct {
+	// TTL defines a period of time after-which the Node should
+	// expire and no longer exist. Values <= 0 are ignored. Given
+	// that the zero-value is ignored, TTL cannot be used to set
+	// a TTL of 0.
+	TTL time.Duration
+}
+
+type SetOptions struct {
+	// PrevValue specifies what the current value of the Node must
+	// be in order for the Set operation to succeed.
+	//
+	// Leaving this field empty means that the caller wishes to
+	// ignore the current value of the Node. This cannot be used
+	// to compare the Node's current value to an empty string.
+	//
+	// PrevValue is ignored if Dir=true
+	PrevValue string
+
+	// PrevIndex indicates what the current ModifiedIndex of the
+	// Node must be in order for the Set operation to succeed.
+	//
+	// If PrevIndex is set to 0 (default), no comparison is made.
+	PrevIndex uint64
+
+	// PrevExist specifies whether the Node must currently exist
+	// (PrevExist) or not (PrevNoExist). If the caller does not
+	// care about existence, set PrevExist to PrevIgnore, or simply
+	// leave it unset.
+	PrevExist PrevExistType
+
+	// TTL defines a period of time after-which the Node should
+	// expire and no longer exist. Values <= 0 are ignored. Given
+	// that the zero-value is ignored, TTL cannot be used to set
+	// a TTL of 0.
+	TTL time.Duration
+
+	// Refresh set to true means a TTL value can be updated
+	// without firing a watch or changing the node value. A
+	// value must not be provided when refreshing a key.
+	Refresh bool
+
+	// Dir specifies whether or not this Node should be created as a directory.
+	Dir bool
+
+	// NoValueOnSuccess specifies whether the response contains the current value of the Node.
+	// If set, the response will only contain the current value when the request fails.
+	NoValueOnSuccess bool
+}
+
+type GetOptions struct {
+	// Recursive defines whether or not all children of the Node
+	// should be returned.
+	Recursive bool
+
+	// Sort instructs the server whether or not to sort the Nodes.
+	// If true, the Nodes are sorted alphabetically by key in
+	// ascending order (A to z). If false (default), the Nodes will
+	// not be sorted and the ordering used should not be considered
+	// predictable.
+	Sort bool
+
+	// Quorum specifies whether it gets the latest committed value that
+	// has been applied in quorum of members, which ensures external
+	// consistency (or linearizability).
+	Quorum bool
+}
+
+type DeleteOptions struct {
+	// PrevValue specifies what the current value of the Node must
+	// be in order for the Delete operation to succeed.
+	//
+	// Leaving this field empty means that the caller wishes to
+	// ignore the current value of the Node. This cannot be used
+	// to compare the Node's current value to an empty string.
+	PrevValue string
+
+	// PrevIndex indicates what the current ModifiedIndex of the
+	// Node must be in order for the Delete operation to succeed.
+	//
+	// If PrevIndex is set to 0 (default), no comparison is made.
+	PrevIndex uint64
+
+	// Recursive defines whether or not all children of the Node
+	// should be deleted. If set to true, all children of the Node
+	// identified by the given key will be deleted. If left unset
+	// or explicitly set to false, only a single Node will be
+	// deleted.
+	Recursive bool
+
+	// Dir specifies whether or not this Node should be removed as a directory.
+	Dir bool
+}
+
+type Watcher interface {
+	// Next blocks until an etcd event occurs, then returns a Response
+	// representing that event. The behavior of Next depends on the
+	// WatcherOptions used to construct the Watcher. Next is designed to
+	// be called repeatedly, each time blocking until a subsequent event
+	// is available.
+	//
+	// If the provided context is cancelled, Next will return a non-nil
+	// error. Any other failures encountered while waiting for the next
+	// event (connection issues, deserialization failures, etc) will
+	// also result in a non-nil error.
+	Next(context.Context) (*Response, error)
+}
+
+type Response struct {
+	// Action is the name of the operation that occurred. Possible values
+	// include get, set, delete, update, create, compareAndSwap,
+	// compareAndDelete and expire.
+	Action string `json:"action"`
+
+	// Node represents the state of the relevant etcd Node.
+	Node *Node `json:"node"`
+
+	// PrevNode represents the previous state of the Node. PrevNode is non-nil
+	// only if the Node existed before the action occurred and the action
+	// caused a change to the Node.
+	PrevNode *Node `json:"prevNode"`
+
+	// Index holds the cluster-level index at the time the Response was generated.
+	// This index is not tied to the Node(s) contained in this Response.
+	Index uint64 `json:"-"`
+
+	// ClusterID holds the cluster-level ID reported by the server.  This
+	// should be different for different etcd clusters.
+	ClusterID string `json:"-"`
+}
+
+type Node struct {
+	// Key represents the unique location of this Node (e.g. "/foo/bar").
+	Key string `json:"key"`
+
+	// Dir reports whether node describes a directory.
+	Dir bool `json:"dir,omitempty"`
+
+	// Value is the current data stored on this Node. If this Node
+	// is a directory, Value will be empty.
+	Value string `json:"value"`
+
+	// Nodes holds the children of this Node, only if this Node is a directory.
+	// This slice of will be arbitrarily deep (children, grandchildren, great-
+	// grandchildren, etc.) if a recursive Get or Watch request were made.
+	Nodes Nodes `json:"nodes"`
+
+	// CreatedIndex is the etcd index at-which this Node was created.
+	CreatedIndex uint64 `json:"createdIndex"`
+
+	// ModifiedIndex is the etcd index at-which this Node was last modified.
+	ModifiedIndex uint64 `json:"modifiedIndex"`
+
+	// Expiration is the server side expiration time of the key.
+	Expiration *time.Time `json:"expiration,omitempty"`
+
+	// TTL is the time to live of the key in second.
+	TTL int64 `json:"ttl,omitempty"`
+}
+
+func (n *Node) String() string {
+	return fmt.Sprintf("{Key: %s, CreatedIndex: %d, ModifiedIndex: %d, TTL: %d}", n.Key, n.CreatedIndex, n.ModifiedIndex, n.TTL)
+}
+
+// TTLDuration returns the Node's TTL as a time.Duration object
+func (n *Node) TTLDuration() time.Duration {
+	return time.Duration(n.TTL) * time.Second
+}
+
+type Nodes []*Node
+
+// interfaces for sorting
+
+func (ns Nodes) Len() int           { return len(ns) }
+func (ns Nodes) Less(i, j int) bool { return ns[i].Key < ns[j].Key }
+func (ns Nodes) Swap(i, j int)      { ns[i], ns[j] = ns[j], ns[i] }
+
+type httpKeysAPI struct {
+	client httpClient
+	prefix string
+}
+
+func (k *httpKeysAPI) Set(ctx context.Context, key, val string, opts *SetOptions) (*Response, error) {
+	act := &setAction{
+		Prefix: k.prefix,
+		Key:    key,
+		Value:  val,
+	}
+
+	if opts != nil {
+		act.PrevValue = opts.PrevValue
+		act.PrevIndex = opts.PrevIndex
+		act.PrevExist = opts.PrevExist
+		act.TTL = opts.TTL
+		act.Refresh = opts.Refresh
+		act.Dir = opts.Dir
+		act.NoValueOnSuccess = opts.NoValueOnSuccess
+	}
+
+	doCtx := ctx
+	if act.PrevExist == PrevNoExist {
+		doCtx = context.WithValue(doCtx, &oneShotCtxValue, &oneShotCtxValue)
+	}
+	resp, body, err := k.client.Do(doCtx, act)
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
+}
+
+func (k *httpKeysAPI) Create(ctx context.Context, key, val string) (*Response, error) {
+	return k.Set(ctx, key, val, &SetOptions{PrevExist: PrevNoExist})
+}
+
+func (k *httpKeysAPI) CreateInOrder(ctx context.Context, dir, val string, opts *CreateInOrderOptions) (*Response, error) {
+	act := &createInOrderAction{
+		Prefix: k.prefix,
+		Dir:    dir,
+		Value:  val,
+	}
+
+	if opts != nil {
+		act.TTL = opts.TTL
+	}
+
+	resp, body, err := k.client.Do(ctx, act)
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
+}
+
+func (k *httpKeysAPI) Update(ctx context.Context, key, val string) (*Response, error) {
+	return k.Set(ctx, key, val, &SetOptions{PrevExist: PrevExist})
+}
+
+func (k *httpKeysAPI) Delete(ctx context.Context, key string, opts *DeleteOptions) (*Response, error) {
+	act := &deleteAction{
+		Prefix: k.prefix,
+		Key:    key,
+	}
+
+	if opts != nil {
+		act.PrevValue = opts.PrevValue
+		act.PrevIndex = opts.PrevIndex
+		act.Dir = opts.Dir
+		act.Recursive = opts.Recursive
+	}
+
+	doCtx := context.WithValue(ctx, &oneShotCtxValue, &oneShotCtxValue)
+	resp, body, err := k.client.Do(doCtx, act)
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
+}
+
+func (k *httpKeysAPI) Get(ctx context.Context, key string, opts *GetOptions) (*Response, error) {
+	act := &getAction{
+		Prefix: k.prefix,
+		Key:    key,
+	}
+
+	if opts != nil {
+		act.Recursive = opts.Recursive
+		act.Sorted = opts.Sort
+		act.Quorum = opts.Quorum
+	}
+
+	resp, body, err := k.client.Do(ctx, act)
+	if err != nil {
+		return nil, err
+	}
+
+	return unmarshalHTTPResponse(resp.StatusCode, resp.Header, body)
+}
+
+func (k *httpKeysAPI) Watcher(key string, opts *WatcherOptions) Watcher {
+	act := waitAction{
+		Prefix: k.prefix,
+		Key:    key,
+	}
+
+	if opts != nil {
+		act.Recursive = opts.Recursive
+		if opts.AfterIndex > 0 {
+			act.WaitIndex = opts.AfterIndex + 1
+		}
+	}
+
+	return &httpWatcher{
+		client:   k.client,
+		nextWait: act,
+	}
+}
+
+type httpWatcher struct {
+	client   httpClient
+	nextWait waitAction
+}
+
+func (hw *httpWatcher) Next(ctx context.Context) (*Response, error) {
+	for {
+		httpresp, body, err := hw.client.Do(ctx, &hw.nextWait)
+		if err != nil {
+			return nil, err
+		}
+
+		resp, err := unmarshalHTTPResponse(httpresp.StatusCode, httpresp.Header, body)
+		if err != nil {
+			if err == ErrEmptyBody {
+				continue
+			}
+			return nil, err
+		}
+
+		hw.nextWait.WaitIndex = resp.Node.ModifiedIndex + 1
+		return resp, nil
+	}
+}
+
+// v2KeysURL forms a URL representing the location of a key.
+// The endpoint argument represents the base URL of an etcd
+// server. The prefix is the path needed to route from the
+// provided endpoint's path to the root of the keys API
+// (typically "/v2/keys").
+func v2KeysURL(ep url.URL, prefix, key string) *url.URL {
+	// We concatenate all parts together manually. We cannot use
+	// path.Join because it does not reserve trailing slash.
+	// We call CanonicalURLPath to further cleanup the path.
+	if prefix != "" && prefix[0] != '/' {
+		prefix = "/" + prefix
+	}
+	if key != "" && key[0] != '/' {
+		key = "/" + key
+	}
+	ep.Path = pathutil.CanonicalURLPath(ep.Path + prefix + key)
+	return &ep
+}
+
+type getAction struct {
+	Prefix    string
+	Key       string
+	Recursive bool
+	Sorted    bool
+	Quorum    bool
+}
+
+func (g *getAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2KeysURL(ep, g.Prefix, g.Key)
+
+	params := u.Query()
+	params.Set("recursive", strconv.FormatBool(g.Recursive))
+	params.Set("sorted", strconv.FormatBool(g.Sorted))
+	params.Set("quorum", strconv.FormatBool(g.Quorum))
+	u.RawQuery = params.Encode()
+
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+type waitAction struct {
+	Prefix    string
+	Key       string
+	WaitIndex uint64
+	Recursive bool
+}
+
+func (w *waitAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2KeysURL(ep, w.Prefix, w.Key)
+
+	params := u.Query()
+	params.Set("wait", "true")
+	params.Set("waitIndex", strconv.FormatUint(w.WaitIndex, 10))
+	params.Set("recursive", strconv.FormatBool(w.Recursive))
+	u.RawQuery = params.Encode()
+
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+type setAction struct {
+	Prefix           string
+	Key              string
+	Value            string
+	PrevValue        string
+	PrevIndex        uint64
+	PrevExist        PrevExistType
+	TTL              time.Duration
+	Refresh          bool
+	Dir              bool
+	NoValueOnSuccess bool
+}
+
+func (a *setAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2KeysURL(ep, a.Prefix, a.Key)
+
+	params := u.Query()
+	form := url.Values{}
+
+	// we're either creating a directory or setting a key
+	if a.Dir {
+		params.Set("dir", strconv.FormatBool(a.Dir))
+	} else {
+		// These options are only valid for setting a key
+		if a.PrevValue != "" {
+			params.Set("prevValue", a.PrevValue)
+		}
+		form.Add("value", a.Value)
+	}
+
+	// Options which apply to both setting a key and creating a dir
+	if a.PrevIndex != 0 {
+		params.Set("prevIndex", strconv.FormatUint(a.PrevIndex, 10))
+	}
+	if a.PrevExist != PrevIgnore {
+		params.Set("prevExist", string(a.PrevExist))
+	}
+	if a.TTL > 0 {
+		form.Add("ttl", strconv.FormatUint(uint64(a.TTL.Seconds()), 10))
+	}
+
+	if a.Refresh {
+		form.Add("refresh", "true")
+	}
+	if a.NoValueOnSuccess {
+		params.Set("noValueOnSuccess", strconv.FormatBool(a.NoValueOnSuccess))
+	}
+
+	u.RawQuery = params.Encode()
+	body := strings.NewReader(form.Encode())
+
+	req, _ := http.NewRequest("PUT", u.String(), body)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	return req
+}
+
+type deleteAction struct {
+	Prefix    string
+	Key       string
+	PrevValue string
+	PrevIndex uint64
+	Dir       bool
+	Recursive bool
+}
+
+func (a *deleteAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2KeysURL(ep, a.Prefix, a.Key)
+
+	params := u.Query()
+	if a.PrevValue != "" {
+		params.Set("prevValue", a.PrevValue)
+	}
+	if a.PrevIndex != 0 {
+		params.Set("prevIndex", strconv.FormatUint(a.PrevIndex, 10))
+	}
+	if a.Dir {
+		params.Set("dir", "true")
+	}
+	if a.Recursive {
+		params.Set("recursive", "true")
+	}
+	u.RawQuery = params.Encode()
+
+	req, _ := http.NewRequest("DELETE", u.String(), nil)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	return req
+}
+
+type createInOrderAction struct {
+	Prefix string
+	Dir    string
+	Value  string
+	TTL    time.Duration
+}
+
+func (a *createInOrderAction) HTTPRequest(ep url.URL) *http.Request {
+	u := v2KeysURL(ep, a.Prefix, a.Dir)
+
+	form := url.Values{}
+	form.Add("value", a.Value)
+	if a.TTL > 0 {
+		form.Add("ttl", strconv.FormatUint(uint64(a.TTL.Seconds()), 10))
+	}
+	body := strings.NewReader(form.Encode())
+
+	req, _ := http.NewRequest("POST", u.String(), body)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	return req
+}
+
+func unmarshalHTTPResponse(code int, header http.Header, body []byte) (res *Response, err error) {
+	switch code {
+	case http.StatusOK, http.StatusCreated:
+		if len(body) == 0 {
+			return nil, ErrEmptyBody
+		}
+		res, err = unmarshalSuccessfulKeysResponse(header, body)
+	default:
+		err = unmarshalFailedKeysResponse(body)
+	}
+	return res, err
+}
+
+var jsonIterator = caseSensitiveJsonIterator()
+
+func unmarshalSuccessfulKeysResponse(header http.Header, body []byte) (*Response, error) {
+	var res Response
+	err := jsonIterator.Unmarshal(body, &res)
+	if err != nil {
+		return nil, ErrInvalidJSON
+	}
+	if header.Get("X-Etcd-Index") != "" {
+		res.Index, err = strconv.ParseUint(header.Get("X-Etcd-Index"), 10, 64)
+		if err != nil {
+			return nil, err
+		}
+	}
+	res.ClusterID = header.Get("X-Etcd-Cluster-ID")
+	return &res, nil
+}
+
+func unmarshalFailedKeysResponse(body []byte) error {
+	var etcdErr Error
+	if err := json.Unmarshal(body, &etcdErr); err != nil {
+		return ErrInvalidJSON
+	}
+	return etcdErr
+}
diff --git a/vendor/go.etcd.io/etcd/client/members.go b/vendor/go.etcd.io/etcd/client/members.go
new file mode 100644
index 0000000..657131a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/members.go
@@ -0,0 +1,303 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"path"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+var (
+	defaultV2MembersPrefix = "/v2/members"
+	defaultLeaderSuffix    = "/leader"
+)
+
+type Member struct {
+	// ID is the unique identifier of this Member.
+	ID string `json:"id"`
+
+	// Name is a human-readable, non-unique identifier of this Member.
+	Name string `json:"name"`
+
+	// PeerURLs represents the HTTP(S) endpoints this Member uses to
+	// participate in etcd's consensus protocol.
+	PeerURLs []string `json:"peerURLs"`
+
+	// ClientURLs represents the HTTP(S) endpoints on which this Member
+	// serves its client-facing APIs.
+	ClientURLs []string `json:"clientURLs"`
+}
+
+type memberCollection []Member
+
+func (c *memberCollection) UnmarshalJSON(data []byte) error {
+	d := struct {
+		Members []Member
+	}{}
+
+	if err := json.Unmarshal(data, &d); err != nil {
+		return err
+	}
+
+	if d.Members == nil {
+		*c = make([]Member, 0)
+		return nil
+	}
+
+	*c = d.Members
+	return nil
+}
+
+type memberCreateOrUpdateRequest struct {
+	PeerURLs types.URLs
+}
+
+func (m *memberCreateOrUpdateRequest) MarshalJSON() ([]byte, error) {
+	s := struct {
+		PeerURLs []string `json:"peerURLs"`
+	}{
+		PeerURLs: make([]string, len(m.PeerURLs)),
+	}
+
+	for i, u := range m.PeerURLs {
+		s.PeerURLs[i] = u.String()
+	}
+
+	return json.Marshal(&s)
+}
+
+// NewMembersAPI constructs a new MembersAPI that uses HTTP to
+// interact with etcd's membership API.
+func NewMembersAPI(c Client) MembersAPI {
+	return &httpMembersAPI{
+		client: c,
+	}
+}
+
+type MembersAPI interface {
+	// List enumerates the current cluster membership.
+	List(ctx context.Context) ([]Member, error)
+
+	// Add instructs etcd to accept a new Member into the cluster.
+	Add(ctx context.Context, peerURL string) (*Member, error)
+
+	// Remove demotes an existing Member out of the cluster.
+	Remove(ctx context.Context, mID string) error
+
+	// Update instructs etcd to update an existing Member in the cluster.
+	Update(ctx context.Context, mID string, peerURLs []string) error
+
+	// Leader gets current leader of the cluster
+	Leader(ctx context.Context) (*Member, error)
+}
+
+type httpMembersAPI struct {
+	client httpClient
+}
+
+func (m *httpMembersAPI) List(ctx context.Context) ([]Member, error) {
+	req := &membersAPIActionList{}
+	resp, body, err := m.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		return nil, err
+	}
+
+	var mCollection memberCollection
+	if err := json.Unmarshal(body, &mCollection); err != nil {
+		return nil, err
+	}
+
+	return []Member(mCollection), nil
+}
+
+func (m *httpMembersAPI) Add(ctx context.Context, peerURL string) (*Member, error) {
+	urls, err := types.NewURLs([]string{peerURL})
+	if err != nil {
+		return nil, err
+	}
+
+	req := &membersAPIActionAdd{peerURLs: urls}
+	resp, body, err := m.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := assertStatusCode(resp.StatusCode, http.StatusCreated, http.StatusConflict); err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode != http.StatusCreated {
+		var merr membersError
+		if err := json.Unmarshal(body, &merr); err != nil {
+			return nil, err
+		}
+		return nil, merr
+	}
+
+	var memb Member
+	if err := json.Unmarshal(body, &memb); err != nil {
+		return nil, err
+	}
+
+	return &memb, nil
+}
+
+func (m *httpMembersAPI) Update(ctx context.Context, memberID string, peerURLs []string) error {
+	urls, err := types.NewURLs(peerURLs)
+	if err != nil {
+		return err
+	}
+
+	req := &membersAPIActionUpdate{peerURLs: urls, memberID: memberID}
+	resp, body, err := m.client.Do(ctx, req)
+	if err != nil {
+		return err
+	}
+
+	if err := assertStatusCode(resp.StatusCode, http.StatusNoContent, http.StatusNotFound, http.StatusConflict); err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusNoContent {
+		var merr membersError
+		if err := json.Unmarshal(body, &merr); err != nil {
+			return err
+		}
+		return merr
+	}
+
+	return nil
+}
+
+func (m *httpMembersAPI) Remove(ctx context.Context, memberID string) error {
+	req := &membersAPIActionRemove{memberID: memberID}
+	resp, _, err := m.client.Do(ctx, req)
+	if err != nil {
+		return err
+	}
+
+	return assertStatusCode(resp.StatusCode, http.StatusNoContent, http.StatusGone)
+}
+
+func (m *httpMembersAPI) Leader(ctx context.Context) (*Member, error) {
+	req := &membersAPIActionLeader{}
+	resp, body, err := m.client.Do(ctx, req)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := assertStatusCode(resp.StatusCode, http.StatusOK); err != nil {
+		return nil, err
+	}
+
+	var leader Member
+	if err := json.Unmarshal(body, &leader); err != nil {
+		return nil, err
+	}
+
+	return &leader, nil
+}
+
+type membersAPIActionList struct{}
+
+func (l *membersAPIActionList) HTTPRequest(ep url.URL) *http.Request {
+	u := v2MembersURL(ep)
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+type membersAPIActionRemove struct {
+	memberID string
+}
+
+func (d *membersAPIActionRemove) HTTPRequest(ep url.URL) *http.Request {
+	u := v2MembersURL(ep)
+	u.Path = path.Join(u.Path, d.memberID)
+	req, _ := http.NewRequest("DELETE", u.String(), nil)
+	return req
+}
+
+type membersAPIActionAdd struct {
+	peerURLs types.URLs
+}
+
+func (a *membersAPIActionAdd) HTTPRequest(ep url.URL) *http.Request {
+	u := v2MembersURL(ep)
+	m := memberCreateOrUpdateRequest{PeerURLs: a.peerURLs}
+	b, _ := json.Marshal(&m)
+	req, _ := http.NewRequest("POST", u.String(), bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+type membersAPIActionUpdate struct {
+	memberID string
+	peerURLs types.URLs
+}
+
+func (a *membersAPIActionUpdate) HTTPRequest(ep url.URL) *http.Request {
+	u := v2MembersURL(ep)
+	m := memberCreateOrUpdateRequest{PeerURLs: a.peerURLs}
+	u.Path = path.Join(u.Path, a.memberID)
+	b, _ := json.Marshal(&m)
+	req, _ := http.NewRequest("PUT", u.String(), bytes.NewReader(b))
+	req.Header.Set("Content-Type", "application/json")
+	return req
+}
+
+func assertStatusCode(got int, want ...int) (err error) {
+	for _, w := range want {
+		if w == got {
+			return nil
+		}
+	}
+	return fmt.Errorf("unexpected status code %d", got)
+}
+
+type membersAPIActionLeader struct{}
+
+func (l *membersAPIActionLeader) HTTPRequest(ep url.URL) *http.Request {
+	u := v2MembersURL(ep)
+	u.Path = path.Join(u.Path, defaultLeaderSuffix)
+	req, _ := http.NewRequest("GET", u.String(), nil)
+	return req
+}
+
+// v2MembersURL add the necessary path to the provided endpoint
+// to route requests to the default v2 members API.
+func v2MembersURL(ep url.URL) *url.URL {
+	ep.Path = path.Join(ep.Path, defaultV2MembersPrefix)
+	return &ep
+}
+
+type membersError struct {
+	Message string `json:"message"`
+	Code    int    `json:"-"`
+}
+
+func (e membersError) Error() string {
+	return e.Message
+}
diff --git a/vendor/go.etcd.io/etcd/client/util.go b/vendor/go.etcd.io/etcd/client/util.go
new file mode 100644
index 0000000..15a8bab
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/client/util.go
@@ -0,0 +1,53 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package client
+
+import (
+	"regexp"
+)
+
+var (
+	roleNotFoundRegExp *regexp.Regexp
+	userNotFoundRegExp *regexp.Regexp
+)
+
+func init() {
+	roleNotFoundRegExp = regexp.MustCompile("auth: Role .* does not exist.")
+	userNotFoundRegExp = regexp.MustCompile("auth: User .* does not exist.")
+}
+
+// IsKeyNotFound returns true if the error code is ErrorCodeKeyNotFound.
+func IsKeyNotFound(err error) bool {
+	if cErr, ok := err.(Error); ok {
+		return cErr.Code == ErrorCodeKeyNotFound
+	}
+	return false
+}
+
+// IsRoleNotFound returns true if the error means role not found of v2 API.
+func IsRoleNotFound(err error) bool {
+	if ae, ok := err.(authError); ok {
+		return roleNotFoundRegExp.MatchString(ae.Message)
+	}
+	return false
+}
+
+// IsUserNotFound returns true if the error means user not found of v2 API.
+func IsUserNotFound(err error) bool {
+	if ae, ok := err.(authError); ok {
+		return userNotFoundRegExp.MatchString(ae.Message)
+	}
+	return false
+}
diff --git a/vendor/go.etcd.io/etcd/embed/config.go b/vendor/go.etcd.io/etcd/embed/config.go
new file mode 100644
index 0000000..2f64d92
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/config.go
@@ -0,0 +1,915 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embed
+
+import (
+	"crypto/tls"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3compactor"
+	"go.etcd.io/etcd/pkg/flags"
+	"go.etcd.io/etcd/pkg/logutil"
+	"go.etcd.io/etcd/pkg/netutil"
+	"go.etcd.io/etcd/pkg/srv"
+	"go.etcd.io/etcd/pkg/tlsutil"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+
+	bolt "go.etcd.io/bbolt"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"golang.org/x/crypto/bcrypt"
+	"google.golang.org/grpc"
+	"sigs.k8s.io/yaml"
+)
+
+const (
+	ClusterStateFlagNew      = "new"
+	ClusterStateFlagExisting = "existing"
+
+	DefaultName                  = "default"
+	DefaultMaxSnapshots          = 5
+	DefaultMaxWALs               = 5
+	DefaultMaxTxnOps             = uint(128)
+	DefaultMaxRequestBytes       = 1.5 * 1024 * 1024
+	DefaultGRPCKeepAliveMinTime  = 5 * time.Second
+	DefaultGRPCKeepAliveInterval = 2 * time.Hour
+	DefaultGRPCKeepAliveTimeout  = 20 * time.Second
+
+	DefaultListenPeerURLs   = "http://localhost:2380"
+	DefaultListenClientURLs = "http://localhost:2379"
+
+	DefaultLogOutput = "default"
+	JournalLogOutput = "systemd/journal"
+	StdErrLogOutput  = "stderr"
+	StdOutLogOutput  = "stdout"
+
+	// DefaultStrictReconfigCheck is the default value for "--strict-reconfig-check" flag.
+	// It's enabled by default.
+	DefaultStrictReconfigCheck = true
+	// DefaultEnableV2 is the default value for "--enable-v2" flag.
+	// v2 API is disabled by default.
+	DefaultEnableV2 = false
+
+	// maxElectionMs specifies the maximum value of election timeout.
+	// More details are listed in ../Documentation/tuning.md#time-parameters.
+	maxElectionMs = 50000
+	// backend freelist map type
+	freelistMapType = "map"
+)
+
+var (
+	ErrConflictBootstrapFlags = fmt.Errorf("multiple discovery or bootstrap flags are set. " +
+		"Choose one of \"initial-cluster\", \"discovery\" or \"discovery-srv\"")
+	ErrUnsetAdvertiseClientURLsFlag = fmt.Errorf("--advertise-client-urls is required when --listen-client-urls is set explicitly")
+
+	DefaultInitialAdvertisePeerURLs = "http://localhost:2380"
+	DefaultAdvertiseClientURLs      = "http://localhost:2379"
+
+	defaultHostname   string
+	defaultHostStatus error
+)
+
+var (
+	// CompactorModePeriodic is periodic compaction mode
+	// for "Config.AutoCompactionMode" field.
+	// If "AutoCompactionMode" is CompactorModePeriodic and
+	// "AutoCompactionRetention" is "1h", it automatically compacts
+	// compacts storage every hour.
+	CompactorModePeriodic = v3compactor.ModePeriodic
+
+	// CompactorModeRevision is revision-based compaction mode
+	// for "Config.AutoCompactionMode" field.
+	// If "AutoCompactionMode" is CompactorModeRevision and
+	// "AutoCompactionRetention" is "1000", it compacts log on
+	// revision 5000 when the current revision is 6000.
+	// This runs every 5-minute if enough of logs have proceeded.
+	CompactorModeRevision = v3compactor.ModeRevision
+)
+
+func init() {
+	defaultHostname, defaultHostStatus = netutil.GetDefaultHost()
+}
+
+// Config holds the arguments for configuring an etcd server.
+type Config struct {
+	Name   string `json:"name"`
+	Dir    string `json:"data-dir"`
+	WalDir string `json:"wal-dir"`
+
+	SnapshotCount uint64 `json:"snapshot-count"`
+
+	// SnapshotCatchUpEntries is the number of entries for a slow follower
+	// to catch-up after compacting the raft storage entries.
+	// We expect the follower has a millisecond level latency with the leader.
+	// The max throughput is around 10K. Keep a 5K entries is enough for helping
+	// follower to catch up.
+	// WARNING: only change this for tests.
+	// Always use "DefaultSnapshotCatchUpEntries"
+	SnapshotCatchUpEntries uint64
+
+	MaxSnapFiles uint `json:"max-snapshots"`
+	MaxWalFiles  uint `json:"max-wals"`
+
+	// TickMs is the number of milliseconds between heartbeat ticks.
+	// TODO: decouple tickMs and heartbeat tick (current heartbeat tick = 1).
+	// make ticks a cluster wide configuration.
+	TickMs     uint `json:"heartbeat-interval"`
+	ElectionMs uint `json:"election-timeout"`
+
+	// InitialElectionTickAdvance is true, then local member fast-forwards
+	// election ticks to speed up "initial" leader election trigger. This
+	// benefits the case of larger election ticks. For instance, cross
+	// datacenter deployment may require longer election timeout of 10-second.
+	// If true, local node does not need wait up to 10-second. Instead,
+	// forwards its election ticks to 8-second, and have only 2-second left
+	// before leader election.
+	//
+	// Major assumptions are that:
+	//  - cluster has no active leader thus advancing ticks enables faster
+	//    leader election, or
+	//  - cluster already has an established leader, and rejoining follower
+	//    is likely to receive heartbeats from the leader after tick advance
+	//    and before election timeout.
+	//
+	// However, when network from leader to rejoining follower is congested,
+	// and the follower does not receive leader heartbeat within left election
+	// ticks, disruptive election has to happen thus affecting cluster
+	// availabilities.
+	//
+	// Disabling this would slow down initial bootstrap process for cross
+	// datacenter deployments. Make your own tradeoffs by configuring
+	// --initial-election-tick-advance at the cost of slow initial bootstrap.
+	//
+	// If single-node, it advances ticks regardless.
+	//
+	// See https://github.com/etcd-io/etcd/issues/9333 for more detail.
+	InitialElectionTickAdvance bool `json:"initial-election-tick-advance"`
+
+	// BackendBatchInterval is the maximum time before commit the backend transaction.
+	BackendBatchInterval time.Duration `json:"backend-batch-interval"`
+	// BackendBatchLimit is the maximum operations before commit the backend transaction.
+	BackendBatchLimit int   `json:"backend-batch-limit"`
+	QuotaBackendBytes int64 `json:"quota-backend-bytes"`
+	MaxTxnOps         uint  `json:"max-txn-ops"`
+	MaxRequestBytes   uint  `json:"max-request-bytes"`
+
+	LPUrls, LCUrls []url.URL
+	APUrls, ACUrls []url.URL
+	ClientTLSInfo  transport.TLSInfo
+	ClientAutoTLS  bool
+	PeerTLSInfo    transport.TLSInfo
+	PeerAutoTLS    bool
+
+	// CipherSuites is a list of supported TLS cipher suites between
+	// client/server and peers. If empty, Go auto-populates the list.
+	// Note that cipher suites are prioritized in the given order.
+	CipherSuites []string `json:"cipher-suites"`
+
+	ClusterState          string `json:"initial-cluster-state"`
+	DNSCluster            string `json:"discovery-srv"`
+	DNSClusterServiceName string `json:"discovery-srv-name"`
+	Dproxy                string `json:"discovery-proxy"`
+	Durl                  string `json:"discovery"`
+	InitialCluster        string `json:"initial-cluster"`
+	InitialClusterToken   string `json:"initial-cluster-token"`
+	StrictReconfigCheck   bool   `json:"strict-reconfig-check"`
+	EnableV2              bool   `json:"enable-v2"`
+
+	// AutoCompactionMode is either 'periodic' or 'revision'.
+	AutoCompactionMode string `json:"auto-compaction-mode"`
+	// AutoCompactionRetention is either duration string with time unit
+	// (e.g. '5m' for 5-minute), or revision unit (e.g. '5000').
+	// If no time unit is provided and compaction mode is 'periodic',
+	// the unit defaults to hour. For example, '5' translates into 5-hour.
+	AutoCompactionRetention string `json:"auto-compaction-retention"`
+
+	// GRPCKeepAliveMinTime is the minimum interval that a client should
+	// wait before pinging server. When client pings "too fast", server
+	// sends goaway and closes the connection (errors: too_many_pings,
+	// http2.ErrCodeEnhanceYourCalm). When too slow, nothing happens.
+	// Server expects client pings only when there is any active streams
+	// (PermitWithoutStream is set false).
+	GRPCKeepAliveMinTime time.Duration `json:"grpc-keepalive-min-time"`
+	// GRPCKeepAliveInterval is the frequency of server-to-client ping
+	// to check if a connection is alive. Close a non-responsive connection
+	// after an additional duration of Timeout. 0 to disable.
+	GRPCKeepAliveInterval time.Duration `json:"grpc-keepalive-interval"`
+	// GRPCKeepAliveTimeout is the additional duration of wait
+	// before closing a non-responsive connection. 0 to disable.
+	GRPCKeepAliveTimeout time.Duration `json:"grpc-keepalive-timeout"`
+
+	// PreVote is true to enable Raft Pre-Vote.
+	// If enabled, Raft runs an additional election phase
+	// to check whether it would get enough votes to win
+	// an election, thus minimizing disruptions.
+	// TODO: enable by default in 3.5.
+	PreVote bool `json:"pre-vote"`
+
+	CORS map[string]struct{}
+
+	// HostWhitelist lists acceptable hostnames from HTTP client requests.
+	// Client origin policy protects against "DNS Rebinding" attacks
+	// to insecure etcd servers. That is, any website can simply create
+	// an authorized DNS name, and direct DNS to "localhost" (or any
+	// other address). Then, all HTTP endpoints of etcd server listening
+	// on "localhost" becomes accessible, thus vulnerable to DNS rebinding
+	// attacks. See "CVE-2018-5702" for more detail.
+	//
+	// 1. If client connection is secure via HTTPS, allow any hostnames.
+	// 2. If client connection is not secure and "HostWhitelist" is not empty,
+	//    only allow HTTP requests whose Host field is listed in whitelist.
+	//
+	// Note that the client origin policy is enforced whether authentication
+	// is enabled or not, for tighter controls.
+	//
+	// By default, "HostWhitelist" is "*", which allows any hostnames.
+	// Note that when specifying hostnames, loopback addresses are not added
+	// automatically. To allow loopback interfaces, leave it empty or set it "*",
+	// or add them to whitelist manually (e.g. "localhost", "127.0.0.1", etc.).
+	//
+	// CVE-2018-5702 reference:
+	// - https://bugs.chromium.org/p/project-zero/issues/detail?id=1447#c2
+	// - https://github.com/transmission/transmission/pull/468
+	// - https://github.com/etcd-io/etcd/issues/9353
+	HostWhitelist map[string]struct{}
+
+	// UserHandlers is for registering users handlers and only used for
+	// embedding etcd into other applications.
+	// The map key is the route path for the handler, and
+	// you must ensure it can't be conflicted with etcd's.
+	UserHandlers map[string]http.Handler `json:"-"`
+	// ServiceRegister is for registering users' gRPC services. A simple usage example:
+	//	cfg := embed.NewConfig()
+	//	cfg.ServerRegister = func(s *grpc.Server) {
+	//		pb.RegisterFooServer(s, &fooServer{})
+	//		pb.RegisterBarServer(s, &barServer{})
+	//	}
+	//	embed.StartEtcd(cfg)
+	ServiceRegister func(*grpc.Server) `json:"-"`
+
+	AuthToken  string `json:"auth-token"`
+	BcryptCost uint   `json:"bcrypt-cost"`
+
+	ExperimentalInitialCorruptCheck bool          `json:"experimental-initial-corrupt-check"`
+	ExperimentalCorruptCheckTime    time.Duration `json:"experimental-corrupt-check-time"`
+	ExperimentalEnableV2V3          string        `json:"experimental-enable-v2v3"`
+	// ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses (array and map are supported types).
+	ExperimentalBackendFreelistType string `json:"experimental-backend-bbolt-freelist-type"`
+	// ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
+	ExperimentalEnableLeaseCheckpoint bool `json:"experimental-enable-lease-checkpoint"`
+	ExperimentalCompactionBatchLimit  int  `json:"experimental-compaction-batch-limit"`
+
+	// ForceNewCluster starts a new cluster even if previously started; unsafe.
+	ForceNewCluster bool `json:"force-new-cluster"`
+
+	EnablePprof           bool   `json:"enable-pprof"`
+	Metrics               string `json:"metrics"`
+	ListenMetricsUrls     []url.URL
+	ListenMetricsUrlsJSON string `json:"listen-metrics-urls"`
+
+	// Logger is logger options: "zap", "capnslog".
+	// WARN: "capnslog" is being deprecated in v3.5.
+	Logger string `json:"logger"`
+	// LogLevel configures log level. Only supports debug, info, warn, error, panic, or fatal. Default 'info'.
+	LogLevel string `json:"log-level"`
+	// LogOutputs is either:
+	//  - "default" as os.Stderr,
+	//  - "stderr" as os.Stderr,
+	//  - "stdout" as os.Stdout,
+	//  - file path to append server logs to.
+	// It can be multiple when "Logger" is zap.
+	LogOutputs []string `json:"log-outputs"`
+
+	// ZapLoggerBuilder is used to build the zap logger.
+	ZapLoggerBuilder func(*Config) error
+
+	// logger logs server-side operations. The default is nil,
+	// and "setupLogging" must be called before starting server.
+	// Do not set logger directly.
+	loggerMu *sync.RWMutex
+	logger   *zap.Logger
+
+	// loggerConfig is server logger configuration for Raft logger.
+	// Must be either: "loggerConfig != nil" or "loggerCore != nil && loggerWriteSyncer != nil".
+	loggerConfig *zap.Config
+	// loggerCore is "zapcore.Core" for raft logger.
+	// Must be either: "loggerConfig != nil" or "loggerCore != nil && loggerWriteSyncer != nil".
+	loggerCore        zapcore.Core
+	loggerWriteSyncer zapcore.WriteSyncer
+
+	// EnableGRPCGateway is false to disable grpc gateway.
+	EnableGRPCGateway bool `json:"enable-grpc-gateway"`
+
+	// TO BE DEPRECATED
+
+	// DeprecatedLogOutput is to be deprecated in v3.5.
+	// Just here for safe migration in v3.4.
+	DeprecatedLogOutput []string `json:"log-output"`
+	// Debug is true, to enable debug level logging.
+	// WARNING: to be deprecated in 3.5. Use "--log-level=debug" instead.
+	Debug bool `json:"debug"`
+	// LogPkgLevels is being deprecated in v3.5.
+	// Only valid if "logger" option is "capnslog".
+	// WARN: DO NOT USE THIS!
+	LogPkgLevels string `json:"log-package-levels"`
+}
+
+// configYAML holds the config suitable for yaml parsing
+type configYAML struct {
+	Config
+	configJSON
+}
+
+// configJSON has file options that are translated into Config options
+type configJSON struct {
+	LPUrlsJSON string `json:"listen-peer-urls"`
+	LCUrlsJSON string `json:"listen-client-urls"`
+	APUrlsJSON string `json:"initial-advertise-peer-urls"`
+	ACUrlsJSON string `json:"advertise-client-urls"`
+
+	CORSJSON          string `json:"cors"`
+	HostWhitelistJSON string `json:"host-whitelist"`
+
+	ClientSecurityJSON securityConfig `json:"client-transport-security"`
+	PeerSecurityJSON   securityConfig `json:"peer-transport-security"`
+}
+
+type securityConfig struct {
+	CertFile      string `json:"cert-file"`
+	KeyFile       string `json:"key-file"`
+	CertAuth      bool   `json:"client-cert-auth"`
+	TrustedCAFile string `json:"trusted-ca-file"`
+	AutoTLS       bool   `json:"auto-tls"`
+}
+
+// NewConfig creates a new Config populated with default values.
+func NewConfig() *Config {
+	lpurl, _ := url.Parse(DefaultListenPeerURLs)
+	apurl, _ := url.Parse(DefaultInitialAdvertisePeerURLs)
+	lcurl, _ := url.Parse(DefaultListenClientURLs)
+	acurl, _ := url.Parse(DefaultAdvertiseClientURLs)
+	cfg := &Config{
+		MaxSnapFiles: DefaultMaxSnapshots,
+		MaxWalFiles:  DefaultMaxWALs,
+
+		Name: DefaultName,
+
+		SnapshotCount:          etcdserver.DefaultSnapshotCount,
+		SnapshotCatchUpEntries: etcdserver.DefaultSnapshotCatchUpEntries,
+
+		MaxTxnOps:       DefaultMaxTxnOps,
+		MaxRequestBytes: DefaultMaxRequestBytes,
+
+		GRPCKeepAliveMinTime:  DefaultGRPCKeepAliveMinTime,
+		GRPCKeepAliveInterval: DefaultGRPCKeepAliveInterval,
+		GRPCKeepAliveTimeout:  DefaultGRPCKeepAliveTimeout,
+
+		TickMs:                     100,
+		ElectionMs:                 1000,
+		InitialElectionTickAdvance: true,
+
+		LPUrls: []url.URL{*lpurl},
+		LCUrls: []url.URL{*lcurl},
+		APUrls: []url.URL{*apurl},
+		ACUrls: []url.URL{*acurl},
+
+		ClusterState:        ClusterStateFlagNew,
+		InitialClusterToken: "etcd-cluster",
+
+		StrictReconfigCheck: DefaultStrictReconfigCheck,
+		Metrics:             "basic",
+		EnableV2:            DefaultEnableV2,
+
+		CORS:          map[string]struct{}{"*": {}},
+		HostWhitelist: map[string]struct{}{"*": {}},
+
+		AuthToken:  "simple",
+		BcryptCost: uint(bcrypt.DefaultCost),
+
+		PreVote: false, // TODO: enable by default in v3.5
+
+		loggerMu:            new(sync.RWMutex),
+		logger:              nil,
+		Logger:              "capnslog",
+		DeprecatedLogOutput: []string{DefaultLogOutput},
+		LogOutputs:          []string{DefaultLogOutput},
+		Debug:               false,
+		LogLevel:            logutil.DefaultLogLevel,
+		LogPkgLevels:        "",
+	}
+	cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
+	return cfg
+}
+
+func logTLSHandshakeFailure(conn *tls.Conn, err error) {
+	state := conn.ConnectionState()
+	remoteAddr := conn.RemoteAddr().String()
+	serverName := state.ServerName
+	if len(state.PeerCertificates) > 0 {
+		cert := state.PeerCertificates[0]
+		ips, dns := cert.IPAddresses, cert.DNSNames
+		plog.Infof("rejected connection from %q (error %q, ServerName %q, IPAddresses %q, DNSNames %q)", remoteAddr, err.Error(), serverName, ips, dns)
+	} else {
+		plog.Infof("rejected connection from %q (error %q, ServerName %q)", remoteAddr, err.Error(), serverName)
+	}
+}
+
+func ConfigFromFile(path string) (*Config, error) {
+	cfg := &configYAML{Config: *NewConfig()}
+	if err := cfg.configFromFile(path); err != nil {
+		return nil, err
+	}
+	return &cfg.Config, nil
+}
+
+func (cfg *configYAML) configFromFile(path string) error {
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err
+	}
+
+	defaultInitialCluster := cfg.InitialCluster
+
+	err = yaml.Unmarshal(b, cfg)
+	if err != nil {
+		return err
+	}
+
+	if cfg.LPUrlsJSON != "" {
+		u, err := types.NewURLs(strings.Split(cfg.LPUrlsJSON, ","))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unexpected error setting up listen-peer-urls: %v\n", err)
+			os.Exit(1)
+		}
+		cfg.LPUrls = []url.URL(u)
+	}
+
+	if cfg.LCUrlsJSON != "" {
+		u, err := types.NewURLs(strings.Split(cfg.LCUrlsJSON, ","))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unexpected error setting up listen-client-urls: %v\n", err)
+			os.Exit(1)
+		}
+		cfg.LCUrls = []url.URL(u)
+	}
+
+	if cfg.APUrlsJSON != "" {
+		u, err := types.NewURLs(strings.Split(cfg.APUrlsJSON, ","))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unexpected error setting up initial-advertise-peer-urls: %v\n", err)
+			os.Exit(1)
+		}
+		cfg.APUrls = []url.URL(u)
+	}
+
+	if cfg.ACUrlsJSON != "" {
+		u, err := types.NewURLs(strings.Split(cfg.ACUrlsJSON, ","))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unexpected error setting up advertise-peer-urls: %v\n", err)
+			os.Exit(1)
+		}
+		cfg.ACUrls = []url.URL(u)
+	}
+
+	if cfg.ListenMetricsUrlsJSON != "" {
+		u, err := types.NewURLs(strings.Split(cfg.ListenMetricsUrlsJSON, ","))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "unexpected error setting up listen-metrics-urls: %v\n", err)
+			os.Exit(1)
+		}
+		cfg.ListenMetricsUrls = []url.URL(u)
+	}
+
+	if cfg.CORSJSON != "" {
+		uv := flags.NewUniqueURLsWithExceptions(cfg.CORSJSON, "*")
+		cfg.CORS = uv.Values
+	}
+
+	if cfg.HostWhitelistJSON != "" {
+		uv := flags.NewUniqueStringsValue(cfg.HostWhitelistJSON)
+		cfg.HostWhitelist = uv.Values
+	}
+
+	// If a discovery flag is set, clear default initial cluster set by InitialClusterFromName
+	if (cfg.Durl != "" || cfg.DNSCluster != "") && cfg.InitialCluster == defaultInitialCluster {
+		cfg.InitialCluster = ""
+	}
+	if cfg.ClusterState == "" {
+		cfg.ClusterState = ClusterStateFlagNew
+	}
+
+	copySecurityDetails := func(tls *transport.TLSInfo, ysc *securityConfig) {
+		tls.CertFile = ysc.CertFile
+		tls.KeyFile = ysc.KeyFile
+		tls.ClientCertAuth = ysc.CertAuth
+		tls.TrustedCAFile = ysc.TrustedCAFile
+	}
+	copySecurityDetails(&cfg.ClientTLSInfo, &cfg.ClientSecurityJSON)
+	copySecurityDetails(&cfg.PeerTLSInfo, &cfg.PeerSecurityJSON)
+	cfg.ClientAutoTLS = cfg.ClientSecurityJSON.AutoTLS
+	cfg.PeerAutoTLS = cfg.PeerSecurityJSON.AutoTLS
+
+	return cfg.Validate()
+}
+
+func updateCipherSuites(tls *transport.TLSInfo, ss []string) error {
+	if len(tls.CipherSuites) > 0 && len(ss) > 0 {
+		return fmt.Errorf("TLSInfo.CipherSuites is already specified (given %v)", ss)
+	}
+	if len(ss) > 0 {
+		cs := make([]uint16, len(ss))
+		for i, s := range ss {
+			var ok bool
+			cs[i], ok = tlsutil.GetCipherSuite(s)
+			if !ok {
+				return fmt.Errorf("unexpected TLS cipher suite %q", s)
+			}
+		}
+		tls.CipherSuites = cs
+	}
+	return nil
+}
+
+// Validate ensures that '*embed.Config' fields are properly configured.
+func (cfg *Config) Validate() error {
+	if err := cfg.setupLogging(); err != nil {
+		return err
+	}
+	if err := checkBindURLs(cfg.LPUrls); err != nil {
+		return err
+	}
+	if err := checkBindURLs(cfg.LCUrls); err != nil {
+		return err
+	}
+	if err := checkBindURLs(cfg.ListenMetricsUrls); err != nil {
+		return err
+	}
+	if err := checkHostURLs(cfg.APUrls); err != nil {
+		addrs := cfg.getAPURLs()
+		return fmt.Errorf(`--initial-advertise-peer-urls %q must be "host:port" (%v)`, strings.Join(addrs, ","), err)
+	}
+	if err := checkHostURLs(cfg.ACUrls); err != nil {
+		addrs := cfg.getACURLs()
+		return fmt.Errorf(`--advertise-client-urls %q must be "host:port" (%v)`, strings.Join(addrs, ","), err)
+	}
+	// Check if conflicting flags are passed.
+	nSet := 0
+	for _, v := range []bool{cfg.Durl != "", cfg.InitialCluster != "", cfg.DNSCluster != ""} {
+		if v {
+			nSet++
+		}
+	}
+
+	if cfg.ClusterState != ClusterStateFlagNew && cfg.ClusterState != ClusterStateFlagExisting {
+		return fmt.Errorf("unexpected clusterState %q", cfg.ClusterState)
+	}
+
+	if nSet > 1 {
+		return ErrConflictBootstrapFlags
+	}
+
+	if cfg.TickMs <= 0 {
+		return fmt.Errorf("--heartbeat-interval must be >0 (set to %dms)", cfg.TickMs)
+	}
+	if cfg.ElectionMs <= 0 {
+		return fmt.Errorf("--election-timeout must be >0 (set to %dms)", cfg.ElectionMs)
+	}
+	if 5*cfg.TickMs > cfg.ElectionMs {
+		return fmt.Errorf("--election-timeout[%vms] should be at least as 5 times as --heartbeat-interval[%vms]", cfg.ElectionMs, cfg.TickMs)
+	}
+	if cfg.ElectionMs > maxElectionMs {
+		return fmt.Errorf("--election-timeout[%vms] is too long, and should be set less than %vms", cfg.ElectionMs, maxElectionMs)
+	}
+
+	// check this last since proxying in etcdmain may make this OK
+	if cfg.LCUrls != nil && cfg.ACUrls == nil {
+		return ErrUnsetAdvertiseClientURLsFlag
+	}
+
+	switch cfg.AutoCompactionMode {
+	case "":
+	case CompactorModeRevision, CompactorModePeriodic:
+	default:
+		return fmt.Errorf("unknown auto-compaction-mode %q", cfg.AutoCompactionMode)
+	}
+
+	return nil
+}
+
+// PeerURLsMapAndToken sets up an initial peer URLsMap and cluster token for bootstrap or discovery.
+func (cfg *Config) PeerURLsMapAndToken(which string) (urlsmap types.URLsMap, token string, err error) {
+	token = cfg.InitialClusterToken
+	switch {
+	case cfg.Durl != "":
+		urlsmap = types.URLsMap{}
+		// If using discovery, generate a temporary cluster based on
+		// self's advertised peer URLs
+		urlsmap[cfg.Name] = cfg.APUrls
+		token = cfg.Durl
+
+	case cfg.DNSCluster != "":
+		clusterStrs, cerr := cfg.GetDNSClusterNames()
+		lg := cfg.logger
+		if cerr != nil {
+			if lg != nil {
+				lg.Warn("failed to resolve during SRV discovery", zap.Error(cerr))
+			} else {
+				plog.Errorf("couldn't resolve during SRV discovery (%v)", cerr)
+			}
+			return nil, "", cerr
+		}
+		for _, s := range clusterStrs {
+			if lg != nil {
+				lg.Info("got bootstrap from DNS for etcd-server", zap.String("node", s))
+			} else {
+				plog.Noticef("got bootstrap from DNS for etcd-server at %s", s)
+			}
+		}
+		clusterStr := strings.Join(clusterStrs, ",")
+		if strings.Contains(clusterStr, "https://") && cfg.PeerTLSInfo.TrustedCAFile == "" {
+			cfg.PeerTLSInfo.ServerName = cfg.DNSCluster
+		}
+		urlsmap, err = types.NewURLsMap(clusterStr)
+		// only etcd member must belong to the discovered cluster.
+		// proxy does not need to belong to the discovered cluster.
+		if which == "etcd" {
+			if _, ok := urlsmap[cfg.Name]; !ok {
+				return nil, "", fmt.Errorf("cannot find local etcd member %q in SRV records", cfg.Name)
+			}
+		}
+
+	default:
+		// We're statically configured, and cluster has appropriately been set.
+		urlsmap, err = types.NewURLsMap(cfg.InitialCluster)
+	}
+	return urlsmap, token, err
+}
+
+// GetDNSClusterNames uses DNS SRV records to get a list of initial nodes for cluster bootstrapping.
+func (cfg *Config) GetDNSClusterNames() ([]string, error) {
+	var (
+		clusterStrs       []string
+		cerr              error
+		serviceNameSuffix string
+	)
+	if cfg.DNSClusterServiceName != "" {
+		serviceNameSuffix = "-" + cfg.DNSClusterServiceName
+	}
+
+	lg := cfg.GetLogger()
+
+	// Use both etcd-server-ssl and etcd-server for discovery.
+	// Combine the results if both are available.
+	clusterStrs, cerr = srv.GetCluster("https", "etcd-server-ssl"+serviceNameSuffix, cfg.Name, cfg.DNSCluster, cfg.APUrls)
+	if cerr != nil {
+		clusterStrs = make([]string, 0)
+	}
+	if lg != nil {
+		lg.Info(
+			"get cluster for etcd-server-ssl SRV",
+			zap.String("service-scheme", "https"),
+			zap.String("service-name", "etcd-server-ssl"+serviceNameSuffix),
+			zap.String("server-name", cfg.Name),
+			zap.String("discovery-srv", cfg.DNSCluster),
+			zap.Strings("advertise-peer-urls", cfg.getAPURLs()),
+			zap.Strings("found-cluster", clusterStrs),
+			zap.Error(cerr),
+		)
+	}
+
+	defaultHTTPClusterStrs, httpCerr := srv.GetCluster("http", "etcd-server"+serviceNameSuffix, cfg.Name, cfg.DNSCluster, cfg.APUrls)
+	if httpCerr != nil {
+		clusterStrs = append(clusterStrs, defaultHTTPClusterStrs...)
+	}
+	if lg != nil {
+		lg.Info(
+			"get cluster for etcd-server SRV",
+			zap.String("service-scheme", "http"),
+			zap.String("service-name", "etcd-server"+serviceNameSuffix),
+			zap.String("server-name", cfg.Name),
+			zap.String("discovery-srv", cfg.DNSCluster),
+			zap.Strings("advertise-peer-urls", cfg.getAPURLs()),
+			zap.Strings("found-cluster", clusterStrs),
+			zap.Error(httpCerr),
+		)
+	}
+
+	return clusterStrs, cerr
+}
+
+func (cfg Config) InitialClusterFromName(name string) (ret string) {
+	if len(cfg.APUrls) == 0 {
+		return ""
+	}
+	n := name
+	if name == "" {
+		n = DefaultName
+	}
+	for i := range cfg.APUrls {
+		ret = ret + "," + n + "=" + cfg.APUrls[i].String()
+	}
+	return ret[1:]
+}
+
+func (cfg Config) IsNewCluster() bool { return cfg.ClusterState == ClusterStateFlagNew }
+func (cfg Config) ElectionTicks() int { return int(cfg.ElectionMs / cfg.TickMs) }
+
+func (cfg Config) defaultPeerHost() bool {
+	return len(cfg.APUrls) == 1 && cfg.APUrls[0].String() == DefaultInitialAdvertisePeerURLs
+}
+
+func (cfg Config) defaultClientHost() bool {
+	return len(cfg.ACUrls) == 1 && cfg.ACUrls[0].String() == DefaultAdvertiseClientURLs
+}
+
+func (cfg *Config) ClientSelfCert() (err error) {
+	if !cfg.ClientAutoTLS {
+		return nil
+	}
+	if !cfg.ClientTLSInfo.Empty() {
+		if cfg.logger != nil {
+			cfg.logger.Warn("ignoring client auto TLS since certs given")
+		} else {
+			plog.Warningf("ignoring client auto TLS since certs given")
+		}
+		return nil
+	}
+	chosts := make([]string, len(cfg.LCUrls))
+	for i, u := range cfg.LCUrls {
+		chosts[i] = u.Host
+	}
+	cfg.ClientTLSInfo, err = transport.SelfCert(cfg.logger, filepath.Join(cfg.Dir, "fixtures", "client"), chosts)
+	if err != nil {
+		return err
+	}
+	return updateCipherSuites(&cfg.ClientTLSInfo, cfg.CipherSuites)
+}
+
+func (cfg *Config) PeerSelfCert() (err error) {
+	if !cfg.PeerAutoTLS {
+		return nil
+	}
+	if !cfg.PeerTLSInfo.Empty() {
+		if cfg.logger != nil {
+			cfg.logger.Warn("ignoring peer auto TLS since certs given")
+		} else {
+			plog.Warningf("ignoring peer auto TLS since certs given")
+		}
+		return nil
+	}
+	phosts := make([]string, len(cfg.LPUrls))
+	for i, u := range cfg.LPUrls {
+		phosts[i] = u.Host
+	}
+	cfg.PeerTLSInfo, err = transport.SelfCert(cfg.logger, filepath.Join(cfg.Dir, "fixtures", "peer"), phosts)
+	if err != nil {
+		return err
+	}
+	return updateCipherSuites(&cfg.PeerTLSInfo, cfg.CipherSuites)
+}
+
+// UpdateDefaultClusterFromName updates cluster advertise URLs with, if available, default host,
+// if advertise URLs are default values(localhost:2379,2380) AND if listen URL is 0.0.0.0.
+// e.g. advertise peer URL localhost:2380 or listen peer URL 0.0.0.0:2380
+// then the advertise peer host would be updated with machine's default host,
+// while keeping the listen URL's port.
+// User can work around this by explicitly setting URL with 127.0.0.1.
+// It returns the default hostname, if used, and the error, if any, from getting the machine's default host.
+// TODO: check whether fields are set instead of whether fields have default value
+func (cfg *Config) UpdateDefaultClusterFromName(defaultInitialCluster string) (string, error) {
+	if defaultHostname == "" || defaultHostStatus != nil {
+		// update 'initial-cluster' when only the name is specified (e.g. 'etcd --name=abc')
+		if cfg.Name != DefaultName && cfg.InitialCluster == defaultInitialCluster {
+			cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
+		}
+		return "", defaultHostStatus
+	}
+
+	used := false
+	pip, pport := cfg.LPUrls[0].Hostname(), cfg.LPUrls[0].Port()
+	if cfg.defaultPeerHost() && pip == "0.0.0.0" {
+		cfg.APUrls[0] = url.URL{Scheme: cfg.APUrls[0].Scheme, Host: fmt.Sprintf("%s:%s", defaultHostname, pport)}
+		used = true
+	}
+	// update 'initial-cluster' when only the name is specified (e.g. 'etcd --name=abc')
+	if cfg.Name != DefaultName && cfg.InitialCluster == defaultInitialCluster {
+		cfg.InitialCluster = cfg.InitialClusterFromName(cfg.Name)
+	}
+
+	cip, cport := cfg.LCUrls[0].Hostname(), cfg.LCUrls[0].Port()
+	if cfg.defaultClientHost() && cip == "0.0.0.0" {
+		cfg.ACUrls[0] = url.URL{Scheme: cfg.ACUrls[0].Scheme, Host: fmt.Sprintf("%s:%s", defaultHostname, cport)}
+		used = true
+	}
+	dhost := defaultHostname
+	if !used {
+		dhost = ""
+	}
+	return dhost, defaultHostStatus
+}
+
+// checkBindURLs returns an error if any URL uses a domain name.
+func checkBindURLs(urls []url.URL) error {
+	for _, url := range urls {
+		if url.Scheme == "unix" || url.Scheme == "unixs" {
+			continue
+		}
+		host, _, err := net.SplitHostPort(url.Host)
+		if err != nil {
+			return err
+		}
+		if host == "localhost" {
+			// special case for local address
+			// TODO: support /etc/hosts ?
+			continue
+		}
+		if net.ParseIP(host) == nil {
+			return fmt.Errorf("expected IP in URL for binding (%s)", url.String())
+		}
+	}
+	return nil
+}
+
+func checkHostURLs(urls []url.URL) error {
+	for _, url := range urls {
+		host, _, err := net.SplitHostPort(url.Host)
+		if err != nil {
+			return err
+		}
+		if host == "" {
+			return fmt.Errorf("unexpected empty host (%s)", url.String())
+		}
+	}
+	return nil
+}
+
+func (cfg *Config) getAPURLs() (ss []string) {
+	ss = make([]string, len(cfg.APUrls))
+	for i := range cfg.APUrls {
+		ss[i] = cfg.APUrls[i].String()
+	}
+	return ss
+}
+
+func (cfg *Config) getLPURLs() (ss []string) {
+	ss = make([]string, len(cfg.LPUrls))
+	for i := range cfg.LPUrls {
+		ss[i] = cfg.LPUrls[i].String()
+	}
+	return ss
+}
+
+func (cfg *Config) getACURLs() (ss []string) {
+	ss = make([]string, len(cfg.ACUrls))
+	for i := range cfg.ACUrls {
+		ss[i] = cfg.ACUrls[i].String()
+	}
+	return ss
+}
+
+func (cfg *Config) getLCURLs() (ss []string) {
+	ss = make([]string, len(cfg.LCUrls))
+	for i := range cfg.LCUrls {
+		ss[i] = cfg.LCUrls[i].String()
+	}
+	return ss
+}
+
+func (cfg *Config) getMetricsURLs() (ss []string) {
+	ss = make([]string, len(cfg.ListenMetricsUrls))
+	for i := range cfg.ListenMetricsUrls {
+		ss[i] = cfg.ListenMetricsUrls[i].String()
+	}
+	return ss
+}
+
+func parseBackendFreelistType(freelistType string) bolt.FreelistType {
+	if freelistType == freelistMapType {
+		return bolt.FreelistMapType
+	}
+
+	return bolt.FreelistArrayType
+}
diff --git a/vendor/go.etcd.io/etcd/embed/config_logging.go b/vendor/go.etcd.io/etcd/embed/config_logging.go
new file mode 100644
index 0000000..e42103c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/config_logging.go
@@ -0,0 +1,312 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embed
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"reflect"
+	"sync"
+
+	"go.etcd.io/etcd/pkg/logutil"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/grpclog"
+)
+
+// GetLogger returns the logger.
+func (cfg Config) GetLogger() *zap.Logger {
+	cfg.loggerMu.RLock()
+	l := cfg.logger
+	cfg.loggerMu.RUnlock()
+	return l
+}
+
+// for testing
+var grpcLogOnce = new(sync.Once)
+
+// setupLogging initializes etcd logging.
+// Must be called after flag parsing or finishing configuring embed.Config.
+func (cfg *Config) setupLogging() error {
+	// handle "DeprecatedLogOutput" in v3.4
+	// TODO: remove "DeprecatedLogOutput" in v3.5
+	len1 := len(cfg.DeprecatedLogOutput)
+	len2 := len(cfg.LogOutputs)
+	if len1 != len2 {
+		switch {
+		case len1 > len2: // deprecate "log-output" flag is used
+			fmt.Fprintln(os.Stderr, "'--log-output' flag has been deprecated! Please use '--log-outputs'!")
+			cfg.LogOutputs = cfg.DeprecatedLogOutput
+		case len1 < len2: // "--log-outputs" flag has been set with multiple writers
+			cfg.DeprecatedLogOutput = []string{}
+		}
+	} else {
+		if len1 > 1 {
+			return errors.New("both '--log-output' and '--log-outputs' are set; only set '--log-outputs'")
+		}
+		if len1 < 1 {
+			return errors.New("either '--log-output' or '--log-outputs' flag must be set")
+		}
+		if reflect.DeepEqual(cfg.DeprecatedLogOutput, cfg.LogOutputs) && cfg.DeprecatedLogOutput[0] != DefaultLogOutput {
+			return fmt.Errorf("'--log-output=%q' and '--log-outputs=%q' are incompatible; only set --log-outputs", cfg.DeprecatedLogOutput, cfg.LogOutputs)
+		}
+		if !reflect.DeepEqual(cfg.DeprecatedLogOutput, []string{DefaultLogOutput}) {
+			fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-output' flag is set to %q\n", cfg.DeprecatedLogOutput)
+			fmt.Fprintln(os.Stderr, "Please use '--log-outputs' flag")
+		}
+	}
+
+	// TODO: remove after deprecating log related flags in v3.5
+	if cfg.Debug {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v (use '--log-level=debug' instead\n", cfg.Debug)
+	}
+	if cfg.Debug && cfg.LogLevel != "debug" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--debug' flag is set to %v with inconsistent '--log-level=%s' flag\n", cfg.Debug, cfg.LogLevel)
+	}
+	if cfg.Logger == "capnslog" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--logger=%s' flag is set; use '--logger=zap' flag instead\n", cfg.Logger)
+	}
+	if cfg.LogPkgLevels != "" {
+		fmt.Fprintf(os.Stderr, "[WARNING] Deprecated '--log-package-levels=%s' flag is set; use '--logger=zap' flag instead\n", cfg.LogPkgLevels)
+	}
+
+	switch cfg.Logger {
+	case "capnslog": // TODO: deprecate this in v3.5
+		cfg.ClientTLSInfo.HandshakeFailure = logTLSHandshakeFailure
+		cfg.PeerTLSInfo.HandshakeFailure = logTLSHandshakeFailure
+
+		if cfg.Debug {
+			capnslog.SetGlobalLogLevel(capnslog.DEBUG)
+			grpc.EnableTracing = true
+			// enable info, warning, error
+			grpclog.SetLoggerV2(grpclog.NewLoggerV2(os.Stderr, os.Stderr, os.Stderr))
+		} else {
+			capnslog.SetGlobalLogLevel(logutil.ConvertToCapnslogLogLevel(cfg.LogLevel))
+			// only discard info
+			grpclog.SetLoggerV2(grpclog.NewLoggerV2(ioutil.Discard, os.Stderr, os.Stderr))
+		}
+
+		// TODO: deprecate with "capnslog"
+		if cfg.LogPkgLevels != "" {
+			repoLog := capnslog.MustRepoLogger("go.etcd.io/etcd")
+			settings, err := repoLog.ParseLogLevelConfig(cfg.LogPkgLevels)
+			if err != nil {
+				plog.Warningf("couldn't parse log level string: %s, continuing with default levels", err.Error())
+				return nil
+			}
+			repoLog.SetLogLevel(settings)
+		}
+
+		if len(cfg.LogOutputs) != 1 {
+			return fmt.Errorf("--logger=capnslog supports only 1 value in '--log-outputs', got %q", cfg.LogOutputs)
+		}
+		// capnslog initially SetFormatter(NewDefaultFormatter(os.Stderr))
+		// where NewDefaultFormatter returns NewJournaldFormatter when syscall.Getppid() == 1
+		// specify 'stdout' or 'stderr' to skip journald logging even when running under systemd
+		output := cfg.LogOutputs[0]
+		switch output {
+		case StdErrLogOutput:
+			capnslog.SetFormatter(capnslog.NewPrettyFormatter(os.Stderr, cfg.Debug))
+		case StdOutLogOutput:
+			capnslog.SetFormatter(capnslog.NewPrettyFormatter(os.Stdout, cfg.Debug))
+		case DefaultLogOutput:
+		default:
+			return fmt.Errorf("unknown log-output %q (only supports %q, %q, %q)", output, DefaultLogOutput, StdErrLogOutput, StdOutLogOutput)
+		}
+
+	case "zap":
+		if len(cfg.LogOutputs) == 0 {
+			cfg.LogOutputs = []string{DefaultLogOutput}
+		}
+		if len(cfg.LogOutputs) > 1 {
+			for _, v := range cfg.LogOutputs {
+				if v == DefaultLogOutput {
+					return fmt.Errorf("multi logoutput for %q is not supported yet", DefaultLogOutput)
+				}
+			}
+		}
+
+		outputPaths, errOutputPaths := make([]string, 0), make([]string, 0)
+		isJournal := false
+		for _, v := range cfg.LogOutputs {
+			switch v {
+			case DefaultLogOutput:
+				outputPaths = append(outputPaths, StdErrLogOutput)
+				errOutputPaths = append(errOutputPaths, StdErrLogOutput)
+
+			case JournalLogOutput:
+				isJournal = true
+
+			case StdErrLogOutput:
+				outputPaths = append(outputPaths, StdErrLogOutput)
+				errOutputPaths = append(errOutputPaths, StdErrLogOutput)
+
+			case StdOutLogOutput:
+				outputPaths = append(outputPaths, StdOutLogOutput)
+				errOutputPaths = append(errOutputPaths, StdOutLogOutput)
+
+			default:
+				outputPaths = append(outputPaths, v)
+				errOutputPaths = append(errOutputPaths, v)
+			}
+		}
+
+		if !isJournal {
+			copied := logutil.DefaultZapLoggerConfig
+			copied.OutputPaths = outputPaths
+			copied.ErrorOutputPaths = errOutputPaths
+			copied = logutil.MergeOutputPaths(copied)
+			copied.Level = zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
+			if cfg.Debug || cfg.LogLevel == "debug" {
+				// enable tracing even when "--debug --log-level info"
+				// in order to keep backward compatibility with <= v3.3
+				// TODO: remove "Debug" check in v3.5
+				grpc.EnableTracing = true
+			}
+			if cfg.ZapLoggerBuilder == nil {
+				cfg.ZapLoggerBuilder = func(c *Config) error {
+					var err error
+					c.logger, err = copied.Build()
+					if err != nil {
+						return err
+					}
+					c.loggerMu.Lock()
+					defer c.loggerMu.Unlock()
+					c.loggerConfig = &copied
+					c.loggerCore = nil
+					c.loggerWriteSyncer = nil
+					grpcLogOnce.Do(func() {
+						// debug true, enable info, warning, error
+						// debug false, only discard info
+						var gl grpclog.LoggerV2
+						gl, err = logutil.NewGRPCLoggerV2(copied)
+						if err == nil {
+							grpclog.SetLoggerV2(gl)
+						}
+					})
+					return nil
+				}
+			}
+		} else {
+			if len(cfg.LogOutputs) > 1 {
+				for _, v := range cfg.LogOutputs {
+					if v != DefaultLogOutput {
+						return fmt.Errorf("running with systemd/journal but other '--log-outputs' values (%q) are configured with 'default'; override 'default' value with something else", cfg.LogOutputs)
+					}
+				}
+			}
+
+			// use stderr as fallback
+			syncer, lerr := getJournalWriteSyncer()
+			if lerr != nil {
+				return lerr
+			}
+
+			lvl := zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
+			if cfg.Debug || cfg.LogLevel == "debug" {
+				// enable tracing even when "--debug --log-level info"
+				// in order to keep backward compatibility with <= v3.3
+				// TODO: remove "Debug" check in v3.5
+				grpc.EnableTracing = true
+			}
+
+			// WARN: do not change field names in encoder config
+			// journald logging writer assumes field names of "level" and "caller"
+			cr := zapcore.NewCore(
+				zapcore.NewJSONEncoder(logutil.DefaultZapLoggerConfig.EncoderConfig),
+				syncer,
+				lvl,
+			)
+			if cfg.ZapLoggerBuilder == nil {
+				cfg.ZapLoggerBuilder = func(c *Config) error {
+					c.logger = zap.New(cr, zap.AddCaller(), zap.ErrorOutput(syncer))
+					c.loggerMu.Lock()
+					defer c.loggerMu.Unlock()
+					c.loggerConfig = nil
+					c.loggerCore = cr
+					c.loggerWriteSyncer = syncer
+
+					grpcLogOnce.Do(func() {
+						grpclog.SetLoggerV2(logutil.NewGRPCLoggerV2FromZapCore(cr, syncer))
+					})
+					return nil
+				}
+			}
+		}
+
+		err := cfg.ZapLoggerBuilder(cfg)
+		if err != nil {
+			return err
+		}
+
+		logTLSHandshakeFailure := func(conn *tls.Conn, err error) {
+			state := conn.ConnectionState()
+			remoteAddr := conn.RemoteAddr().String()
+			serverName := state.ServerName
+			if len(state.PeerCertificates) > 0 {
+				cert := state.PeerCertificates[0]
+				ips := make([]string, len(cert.IPAddresses))
+				for i := range cert.IPAddresses {
+					ips[i] = cert.IPAddresses[i].String()
+				}
+				cfg.logger.Warn(
+					"rejected connection",
+					zap.String("remote-addr", remoteAddr),
+					zap.String("server-name", serverName),
+					zap.Strings("ip-addresses", ips),
+					zap.Strings("dns-names", cert.DNSNames),
+					zap.Error(err),
+				)
+			} else {
+				cfg.logger.Warn(
+					"rejected connection",
+					zap.String("remote-addr", remoteAddr),
+					zap.String("server-name", serverName),
+					zap.Error(err),
+				)
+			}
+		}
+		cfg.ClientTLSInfo.HandshakeFailure = logTLSHandshakeFailure
+		cfg.PeerTLSInfo.HandshakeFailure = logTLSHandshakeFailure
+
+	default:
+		return fmt.Errorf("unknown logger option %q", cfg.Logger)
+	}
+
+	return nil
+}
+
+// NewZapCoreLoggerBuilder generates a zap core logger builder.
+func NewZapCoreLoggerBuilder(lg *zap.Logger, cr zapcore.Core, syncer zapcore.WriteSyncer) func(*Config) error {
+	return func(cfg *Config) error {
+		cfg.loggerMu.Lock()
+		defer cfg.loggerMu.Unlock()
+		cfg.logger = lg
+		cfg.loggerConfig = nil
+		cfg.loggerCore = cr
+		cfg.loggerWriteSyncer = syncer
+
+		grpcLogOnce.Do(func() {
+			grpclog.SetLoggerV2(logutil.NewGRPCLoggerV2FromZapCore(cr, syncer))
+		})
+		return nil
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/embed/config_logging_journal_unix.go b/vendor/go.etcd.io/etcd/embed/config_logging_journal_unix.go
new file mode 100644
index 0000000..44a51d6
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/config_logging_journal_unix.go
@@ -0,0 +1,35 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows
+
+package embed
+
+import (
+	"fmt"
+	"os"
+
+	"go.etcd.io/etcd/pkg/logutil"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// use stderr as fallback
+func getJournalWriteSyncer() (zapcore.WriteSyncer, error) {
+	jw, err := logutil.NewJournalWriter(os.Stderr)
+	if err != nil {
+		return nil, fmt.Errorf("can't find journal (%v)", err)
+	}
+	return zapcore.AddSync(jw), nil
+}
diff --git a/vendor/go.etcd.io/etcd/embed/config_logging_journal_windows.go b/vendor/go.etcd.io/etcd/embed/config_logging_journal_windows.go
new file mode 100644
index 0000000..5b76256
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/config_logging_journal_windows.go
@@ -0,0 +1,27 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build windows
+
+package embed
+
+import (
+	"os"
+
+	"go.uber.org/zap/zapcore"
+)
+
+func getJournalWriteSyncer() (zapcore.WriteSyncer, error) {
+	return zapcore.AddSync(os.Stderr), nil
+}
diff --git a/vendor/go.etcd.io/etcd/embed/doc.go b/vendor/go.etcd.io/etcd/embed/doc.go
new file mode 100644
index 0000000..4811bb6
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/doc.go
@@ -0,0 +1,45 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package embed provides bindings for embedding an etcd server in a program.
+
+Launch an embedded etcd server using the configuration defaults:
+
+	import (
+		"log"
+		"time"
+
+		"go.etcd.io/etcd/embed"
+	)
+
+	func main() {
+		cfg := embed.NewConfig()
+		cfg.Dir = "default.etcd"
+		e, err := embed.StartEtcd(cfg)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer e.Close()
+		select {
+		case <-e.Server.ReadyNotify():
+			log.Printf("Server is ready!")
+		case <-time.After(60 * time.Second):
+			e.Server.Stop() // trigger a shutdown
+			log.Printf("Server took too long to start!")
+		}
+		log.Fatal(<-e.Err())
+	}
+*/
+package embed
diff --git a/vendor/go.etcd.io/etcd/embed/etcd.go b/vendor/go.etcd.io/etcd/embed/etcd.go
new file mode 100644
index 0000000..ac7dbc9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/etcd.go
@@ -0,0 +1,829 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embed
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"io/ioutil"
+	defaultLog "log"
+	"net"
+	"net/http"
+	"net/url"
+	"runtime"
+	"sort"
+	"strconv"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/etcdhttp"
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
+	"go.etcd.io/etcd/etcdserver/api/v2http"
+	"go.etcd.io/etcd/etcdserver/api/v2v3"
+	"go.etcd.io/etcd/etcdserver/api/v3client"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc"
+	"go.etcd.io/etcd/pkg/debugutil"
+	runtimeutil "go.etcd.io/etcd/pkg/runtime"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/pkg/capnslog"
+	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
+	"github.com/soheilhy/cmux"
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/keepalive"
+)
+
+var plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "embed")
+
+const (
+	// internal fd usage includes disk usage and transport usage.
+	// To read/write snapshot, snap pkg needs 1. In normal case, wal pkg needs
+	// at most 2 to read/lock/write WALs. One case that it needs to 2 is to
+	// read all logs after some snapshot index, which locates at the end of
+	// the second last and the head of the last. For purging, it needs to read
+	// directory, so it needs 1. For fd monitor, it needs 1.
+	// For transport, rafthttp builds two long-polling connections and at most
+	// four temporary connections with each member. There are at most 9 members
+	// in a cluster, so it should reserve 96.
+	// For the safety, we set the total reserved number to 150.
+	reservedInternalFDNum = 150
+)
+
+// Etcd contains a running etcd server and its listeners.
+type Etcd struct {
+	Peers   []*peerListener
+	Clients []net.Listener
+	// a map of contexts for the servers that serves client requests.
+	sctxs            map[string]*serveCtx
+	metricsListeners []net.Listener
+
+	Server *etcdserver.EtcdServer
+
+	cfg   Config
+	stopc chan struct{}
+	errc  chan error
+
+	closeOnce sync.Once
+}
+
+type peerListener struct {
+	net.Listener
+	serve func() error
+	close func(context.Context) error
+}
+
+// StartEtcd launches the etcd server and HTTP handlers for client/server communication.
+// The returned Etcd.Server is not guaranteed to have joined the cluster. Wait
+// on the Etcd.Server.ReadyNotify() channel to know when it completes and is ready for use.
+func StartEtcd(inCfg *Config) (e *Etcd, err error) {
+	if err = inCfg.Validate(); err != nil {
+		return nil, err
+	}
+	serving := false
+	e = &Etcd{cfg: *inCfg, stopc: make(chan struct{})}
+	cfg := &e.cfg
+	defer func() {
+		if e == nil || err == nil {
+			return
+		}
+		if !serving {
+			// errored before starting gRPC server for serveCtx.serversC
+			for _, sctx := range e.sctxs {
+				close(sctx.serversC)
+			}
+		}
+		e.Close()
+		e = nil
+	}()
+
+	if e.cfg.logger != nil {
+		e.cfg.logger.Info(
+			"configuring peer listeners",
+			zap.Strings("listen-peer-urls", e.cfg.getLPURLs()),
+		)
+	}
+	if e.Peers, err = configurePeerListeners(cfg); err != nil {
+		return e, err
+	}
+
+	if e.cfg.logger != nil {
+		e.cfg.logger.Info(
+			"configuring client listeners",
+			zap.Strings("listen-client-urls", e.cfg.getLCURLs()),
+		)
+	}
+	if e.sctxs, err = configureClientListeners(cfg); err != nil {
+		return e, err
+	}
+
+	for _, sctx := range e.sctxs {
+		e.Clients = append(e.Clients, sctx.l)
+	}
+
+	var (
+		urlsmap types.URLsMap
+		token   string
+	)
+	memberInitialized := true
+	if !isMemberInitialized(cfg) {
+		memberInitialized = false
+		urlsmap, token, err = cfg.PeerURLsMapAndToken("etcd")
+		if err != nil {
+			return e, fmt.Errorf("error setting up initial cluster: %v", err)
+		}
+	}
+
+	// AutoCompactionRetention defaults to "0" if not set.
+	if len(cfg.AutoCompactionRetention) == 0 {
+		cfg.AutoCompactionRetention = "0"
+	}
+	autoCompactionRetention, err := parseCompactionRetention(cfg.AutoCompactionMode, cfg.AutoCompactionRetention)
+	if err != nil {
+		return e, err
+	}
+
+	backendFreelistType := parseBackendFreelistType(cfg.ExperimentalBackendFreelistType)
+
+	srvcfg := etcdserver.ServerConfig{
+		Name:                       cfg.Name,
+		ClientURLs:                 cfg.ACUrls,
+		PeerURLs:                   cfg.APUrls,
+		DataDir:                    cfg.Dir,
+		DedicatedWALDir:            cfg.WalDir,
+		SnapshotCount:              cfg.SnapshotCount,
+		SnapshotCatchUpEntries:     cfg.SnapshotCatchUpEntries,
+		MaxSnapFiles:               cfg.MaxSnapFiles,
+		MaxWALFiles:                cfg.MaxWalFiles,
+		InitialPeerURLsMap:         urlsmap,
+		InitialClusterToken:        token,
+		DiscoveryURL:               cfg.Durl,
+		DiscoveryProxy:             cfg.Dproxy,
+		NewCluster:                 cfg.IsNewCluster(),
+		PeerTLSInfo:                cfg.PeerTLSInfo,
+		TickMs:                     cfg.TickMs,
+		ElectionTicks:              cfg.ElectionTicks(),
+		InitialElectionTickAdvance: cfg.InitialElectionTickAdvance,
+		AutoCompactionRetention:    autoCompactionRetention,
+		AutoCompactionMode:         cfg.AutoCompactionMode,
+		QuotaBackendBytes:          cfg.QuotaBackendBytes,
+		BackendBatchLimit:          cfg.BackendBatchLimit,
+		BackendFreelistType:        backendFreelistType,
+		BackendBatchInterval:       cfg.BackendBatchInterval,
+		MaxTxnOps:                  cfg.MaxTxnOps,
+		MaxRequestBytes:            cfg.MaxRequestBytes,
+		StrictReconfigCheck:        cfg.StrictReconfigCheck,
+		ClientCertAuthEnabled:      cfg.ClientTLSInfo.ClientCertAuth,
+		AuthToken:                  cfg.AuthToken,
+		BcryptCost:                 cfg.BcryptCost,
+		CORS:                       cfg.CORS,
+		HostWhitelist:              cfg.HostWhitelist,
+		InitialCorruptCheck:        cfg.ExperimentalInitialCorruptCheck,
+		CorruptCheckTime:           cfg.ExperimentalCorruptCheckTime,
+		PreVote:                    cfg.PreVote,
+		Logger:                     cfg.logger,
+		LoggerConfig:               cfg.loggerConfig,
+		LoggerCore:                 cfg.loggerCore,
+		LoggerWriteSyncer:          cfg.loggerWriteSyncer,
+		Debug:                      cfg.Debug,
+		ForceNewCluster:            cfg.ForceNewCluster,
+		EnableGRPCGateway:          cfg.EnableGRPCGateway,
+		EnableLeaseCheckpoint:      cfg.ExperimentalEnableLeaseCheckpoint,
+		CompactionBatchLimit:       cfg.ExperimentalCompactionBatchLimit,
+	}
+	print(e.cfg.logger, *cfg, srvcfg, memberInitialized)
+	if e.Server, err = etcdserver.NewServer(srvcfg); err != nil {
+		return e, err
+	}
+
+	// buffer channel so goroutines on closed connections won't wait forever
+	e.errc = make(chan error, len(e.Peers)+len(e.Clients)+2*len(e.sctxs))
+
+	// newly started member ("memberInitialized==false")
+	// does not need corruption check
+	if memberInitialized {
+		if err = e.Server.CheckInitialHashKV(); err != nil {
+			// set "EtcdServer" to nil, so that it does not block on "EtcdServer.Close()"
+			// (nothing to close since rafthttp transports have not been started)
+			e.Server = nil
+			return e, err
+		}
+	}
+	e.Server.Start()
+
+	if err = e.servePeers(); err != nil {
+		return e, err
+	}
+	if err = e.serveClients(); err != nil {
+		return e, err
+	}
+	if err = e.serveMetrics(); err != nil {
+		return e, err
+	}
+
+	if e.cfg.logger != nil {
+		e.cfg.logger.Info(
+			"now serving peer/client/metrics",
+			zap.String("local-member-id", e.Server.ID().String()),
+			zap.Strings("initial-advertise-peer-urls", e.cfg.getAPURLs()),
+			zap.Strings("listen-peer-urls", e.cfg.getLPURLs()),
+			zap.Strings("advertise-client-urls", e.cfg.getACURLs()),
+			zap.Strings("listen-client-urls", e.cfg.getLCURLs()),
+			zap.Strings("listen-metrics-urls", e.cfg.getMetricsURLs()),
+		)
+	}
+	serving = true
+	return e, nil
+}
+
+func print(lg *zap.Logger, ec Config, sc etcdserver.ServerConfig, memberInitialized bool) {
+	// TODO: remove this after dropping "capnslog"
+	if lg == nil {
+		plog.Infof("name = %s", ec.Name)
+		if sc.ForceNewCluster {
+			plog.Infof("force new cluster")
+		}
+		plog.Infof("data dir = %s", sc.DataDir)
+		plog.Infof("member dir = %s", sc.MemberDir())
+		if sc.DedicatedWALDir != "" {
+			plog.Infof("dedicated WAL dir = %s", sc.DedicatedWALDir)
+		}
+		plog.Infof("heartbeat = %dms", sc.TickMs)
+		plog.Infof("election = %dms", sc.ElectionTicks*int(sc.TickMs))
+		plog.Infof("snapshot count = %d", sc.SnapshotCount)
+		if len(sc.DiscoveryURL) != 0 {
+			plog.Infof("discovery URL= %s", sc.DiscoveryURL)
+			if len(sc.DiscoveryProxy) != 0 {
+				plog.Infof("discovery proxy = %s", sc.DiscoveryProxy)
+			}
+		}
+		plog.Infof("advertise client URLs = %s", sc.ClientURLs)
+		if memberInitialized {
+			plog.Infof("initial advertise peer URLs = %s", sc.PeerURLs)
+			plog.Infof("initial cluster = %s", sc.InitialPeerURLsMap)
+		}
+	} else {
+		cors := make([]string, 0, len(ec.CORS))
+		for v := range ec.CORS {
+			cors = append(cors, v)
+		}
+		sort.Strings(cors)
+
+		hss := make([]string, 0, len(ec.HostWhitelist))
+		for v := range ec.HostWhitelist {
+			hss = append(hss, v)
+		}
+		sort.Strings(hss)
+
+		quota := ec.QuotaBackendBytes
+		if quota == 0 {
+			quota = etcdserver.DefaultQuotaBytes
+		}
+
+		lg.Info(
+			"starting an etcd server",
+			zap.String("etcd-version", version.Version),
+			zap.String("git-sha", version.GitSHA),
+			zap.String("go-version", runtime.Version()),
+			zap.String("go-os", runtime.GOOS),
+			zap.String("go-arch", runtime.GOARCH),
+			zap.Int("max-cpu-set", runtime.GOMAXPROCS(0)),
+			zap.Int("max-cpu-available", runtime.NumCPU()),
+			zap.Bool("member-initialized", memberInitialized),
+			zap.String("name", sc.Name),
+			zap.String("data-dir", sc.DataDir),
+			zap.String("wal-dir", ec.WalDir),
+			zap.String("wal-dir-dedicated", sc.DedicatedWALDir),
+			zap.String("member-dir", sc.MemberDir()),
+			zap.Bool("force-new-cluster", sc.ForceNewCluster),
+			zap.String("heartbeat-interval", fmt.Sprintf("%v", time.Duration(sc.TickMs)*time.Millisecond)),
+			zap.String("election-timeout", fmt.Sprintf("%v", time.Duration(sc.ElectionTicks*int(sc.TickMs))*time.Millisecond)),
+			zap.Bool("initial-election-tick-advance", sc.InitialElectionTickAdvance),
+			zap.Uint64("snapshot-count", sc.SnapshotCount),
+			zap.Uint64("snapshot-catchup-entries", sc.SnapshotCatchUpEntries),
+			zap.Strings("initial-advertise-peer-urls", ec.getAPURLs()),
+			zap.Strings("listen-peer-urls", ec.getLPURLs()),
+			zap.Strings("advertise-client-urls", ec.getACURLs()),
+			zap.Strings("listen-client-urls", ec.getLCURLs()),
+			zap.Strings("listen-metrics-urls", ec.getMetricsURLs()),
+			zap.Strings("cors", cors),
+			zap.Strings("host-whitelist", hss),
+			zap.String("initial-cluster", sc.InitialPeerURLsMap.String()),
+			zap.String("initial-cluster-state", ec.ClusterState),
+			zap.String("initial-cluster-token", sc.InitialClusterToken),
+			zap.Int64("quota-size-bytes", quota),
+			zap.Bool("pre-vote", sc.PreVote),
+			zap.Bool("initial-corrupt-check", sc.InitialCorruptCheck),
+			zap.String("corrupt-check-time-interval", sc.CorruptCheckTime.String()),
+			zap.String("auto-compaction-mode", sc.AutoCompactionMode),
+			zap.Duration("auto-compaction-retention", sc.AutoCompactionRetention),
+			zap.String("auto-compaction-interval", sc.AutoCompactionRetention.String()),
+			zap.String("discovery-url", sc.DiscoveryURL),
+			zap.String("discovery-proxy", sc.DiscoveryProxy),
+		)
+	}
+}
+
+// Config returns the current configuration.
+func (e *Etcd) Config() Config {
+	return e.cfg
+}
+
+// Close gracefully shuts down all servers/listeners.
+// Client requests will be terminated with request timeout.
+// After timeout, enforce remaning requests be closed immediately.
+func (e *Etcd) Close() {
+	fields := []zap.Field{
+		zap.String("name", e.cfg.Name),
+		zap.String("data-dir", e.cfg.Dir),
+		zap.Strings("advertise-peer-urls", e.cfg.getAPURLs()),
+		zap.Strings("advertise-client-urls", e.cfg.getACURLs()),
+	}
+	lg := e.GetLogger()
+	if lg != nil {
+		lg.Info("closing etcd server", fields...)
+	}
+	defer func() {
+		if lg != nil {
+			lg.Info("closed etcd server", fields...)
+			lg.Sync()
+		}
+	}()
+
+	e.closeOnce.Do(func() { close(e.stopc) })
+
+	// close client requests with request timeout
+	timeout := 2 * time.Second
+	if e.Server != nil {
+		timeout = e.Server.Cfg.ReqTimeout()
+	}
+	for _, sctx := range e.sctxs {
+		for ss := range sctx.serversC {
+			ctx, cancel := context.WithTimeout(context.Background(), timeout)
+			stopServers(ctx, ss)
+			cancel()
+		}
+	}
+
+	for _, sctx := range e.sctxs {
+		sctx.cancel()
+	}
+
+	for i := range e.Clients {
+		if e.Clients[i] != nil {
+			e.Clients[i].Close()
+		}
+	}
+
+	for i := range e.metricsListeners {
+		e.metricsListeners[i].Close()
+	}
+
+	// close rafthttp transports
+	if e.Server != nil {
+		e.Server.Stop()
+	}
+
+	// close all idle connections in peer handler (wait up to 1-second)
+	for i := range e.Peers {
+		if e.Peers[i] != nil && e.Peers[i].close != nil {
+			ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+			e.Peers[i].close(ctx)
+			cancel()
+		}
+	}
+}
+
+func stopServers(ctx context.Context, ss *servers) {
+	shutdownNow := func() {
+		// first, close the http.Server
+		ss.http.Shutdown(ctx)
+		// then close grpc.Server; cancels all active RPCs
+		ss.grpc.Stop()
+	}
+
+	// do not grpc.Server.GracefulStop with TLS enabled etcd server
+	// See https://github.com/grpc/grpc-go/issues/1384#issuecomment-317124531
+	// and https://github.com/etcd-io/etcd/issues/8916
+	if ss.secure {
+		shutdownNow()
+		return
+	}
+
+	ch := make(chan struct{})
+	go func() {
+		defer close(ch)
+		// close listeners to stop accepting new connections,
+		// will block on any existing transports
+		ss.grpc.GracefulStop()
+	}()
+
+	// wait until all pending RPCs are finished
+	select {
+	case <-ch:
+	case <-ctx.Done():
+		// took too long, manually close open transports
+		// e.g. watch streams
+		shutdownNow()
+
+		// concurrent GracefulStop should be interrupted
+		<-ch
+	}
+}
+
+func (e *Etcd) Err() <-chan error { return e.errc }
+
+func configurePeerListeners(cfg *Config) (peers []*peerListener, err error) {
+	if err = updateCipherSuites(&cfg.PeerTLSInfo, cfg.CipherSuites); err != nil {
+		return nil, err
+	}
+	if err = cfg.PeerSelfCert(); err != nil {
+		if cfg.logger != nil {
+			cfg.logger.Fatal("failed to get peer self-signed certs", zap.Error(err))
+		} else {
+			plog.Fatalf("could not get certs (%v)", err)
+		}
+	}
+	if !cfg.PeerTLSInfo.Empty() {
+		if cfg.logger != nil {
+			cfg.logger.Info(
+				"starting with peer TLS",
+				zap.String("tls-info", fmt.Sprintf("%+v", cfg.PeerTLSInfo)),
+				zap.Strings("cipher-suites", cfg.CipherSuites),
+			)
+		} else {
+			plog.Infof("peerTLS: %s", cfg.PeerTLSInfo)
+		}
+	}
+
+	peers = make([]*peerListener, len(cfg.LPUrls))
+	defer func() {
+		if err == nil {
+			return
+		}
+		for i := range peers {
+			if peers[i] != nil && peers[i].close != nil {
+				if cfg.logger != nil {
+					cfg.logger.Warn(
+						"closing peer listener",
+						zap.String("address", cfg.LPUrls[i].String()),
+						zap.Error(err),
+					)
+				} else {
+					plog.Info("stopping listening for peers on ", cfg.LPUrls[i].String())
+				}
+				ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+				peers[i].close(ctx)
+				cancel()
+			}
+		}
+	}()
+
+	for i, u := range cfg.LPUrls {
+		if u.Scheme == "http" {
+			if !cfg.PeerTLSInfo.Empty() {
+				if cfg.logger != nil {
+					cfg.logger.Warn("scheme is HTTP while key and cert files are present; ignoring key and cert files", zap.String("peer-url", u.String()))
+				} else {
+					plog.Warningf("The scheme of peer url %s is HTTP while peer key/cert files are presented. Ignored peer key/cert files.", u.String())
+				}
+			}
+			if cfg.PeerTLSInfo.ClientCertAuth {
+				if cfg.logger != nil {
+					cfg.logger.Warn("scheme is HTTP while --peer-client-cert-auth is enabled; ignoring client cert auth for this URL", zap.String("peer-url", u.String()))
+				} else {
+					plog.Warningf("The scheme of peer url %s is HTTP while client cert auth (--peer-client-cert-auth) is enabled. Ignored client cert auth for this url.", u.String())
+				}
+			}
+		}
+		peers[i] = &peerListener{close: func(context.Context) error { return nil }}
+		peers[i].Listener, err = rafthttp.NewListener(u, &cfg.PeerTLSInfo)
+		if err != nil {
+			return nil, err
+		}
+		// once serve, overwrite with 'http.Server.Shutdown'
+		peers[i].close = func(context.Context) error {
+			return peers[i].Listener.Close()
+		}
+	}
+	return peers, nil
+}
+
+// configure peer handlers after rafthttp.Transport started
+func (e *Etcd) servePeers() (err error) {
+	ph := etcdhttp.NewPeerHandler(e.GetLogger(), e.Server)
+	var peerTLScfg *tls.Config
+	if !e.cfg.PeerTLSInfo.Empty() {
+		if peerTLScfg, err = e.cfg.PeerTLSInfo.ServerConfig(); err != nil {
+			return err
+		}
+	}
+
+	for _, p := range e.Peers {
+		u := p.Listener.Addr().String()
+		gs := v3rpc.Server(e.Server, peerTLScfg)
+		m := cmux.New(p.Listener)
+		go gs.Serve(m.Match(cmux.HTTP2()))
+		srv := &http.Server{
+			Handler:     grpcHandlerFunc(gs, ph),
+			ReadTimeout: 5 * time.Minute,
+			ErrorLog:    defaultLog.New(ioutil.Discard, "", 0), // do not log user error
+		}
+		go srv.Serve(m.Match(cmux.Any()))
+		p.serve = func() error { return m.Serve() }
+		p.close = func(ctx context.Context) error {
+			// gracefully shutdown http.Server
+			// close open listeners, idle connections
+			// until context cancel or time-out
+			if e.cfg.logger != nil {
+				e.cfg.logger.Info(
+					"stopping serving peer traffic",
+					zap.String("address", u),
+				)
+			}
+			stopServers(ctx, &servers{secure: peerTLScfg != nil, grpc: gs, http: srv})
+			if e.cfg.logger != nil {
+				e.cfg.logger.Info(
+					"stopped serving peer traffic",
+					zap.String("address", u),
+				)
+			}
+			return nil
+		}
+	}
+
+	// start peer servers in a goroutine
+	for _, pl := range e.Peers {
+		go func(l *peerListener) {
+			u := l.Addr().String()
+			if e.cfg.logger != nil {
+				e.cfg.logger.Info(
+					"serving peer traffic",
+					zap.String("address", u),
+				)
+			} else {
+				plog.Info("listening for peers on ", u)
+			}
+			e.errHandler(l.serve())
+		}(pl)
+	}
+	return nil
+}
+
+func configureClientListeners(cfg *Config) (sctxs map[string]*serveCtx, err error) {
+	if err = updateCipherSuites(&cfg.ClientTLSInfo, cfg.CipherSuites); err != nil {
+		return nil, err
+	}
+	if err = cfg.ClientSelfCert(); err != nil {
+		if cfg.logger != nil {
+			cfg.logger.Fatal("failed to get client self-signed certs", zap.Error(err))
+		} else {
+			plog.Fatalf("could not get certs (%v)", err)
+		}
+	}
+	if cfg.EnablePprof {
+		if cfg.logger != nil {
+			cfg.logger.Info("pprof is enabled", zap.String("path", debugutil.HTTPPrefixPProf))
+		} else {
+			plog.Infof("pprof is enabled under %s", debugutil.HTTPPrefixPProf)
+		}
+	}
+
+	sctxs = make(map[string]*serveCtx)
+	for _, u := range cfg.LCUrls {
+		sctx := newServeCtx(cfg.logger)
+		if u.Scheme == "http" || u.Scheme == "unix" {
+			if !cfg.ClientTLSInfo.Empty() {
+				if cfg.logger != nil {
+					cfg.logger.Warn("scheme is HTTP while key and cert files are present; ignoring key and cert files", zap.String("client-url", u.String()))
+				} else {
+					plog.Warningf("The scheme of client url %s is HTTP while peer key/cert files are presented. Ignored key/cert files.", u.String())
+				}
+			}
+			if cfg.ClientTLSInfo.ClientCertAuth {
+				if cfg.logger != nil {
+					cfg.logger.Warn("scheme is HTTP while --client-cert-auth is enabled; ignoring client cert auth for this URL", zap.String("client-url", u.String()))
+				} else {
+					plog.Warningf("The scheme of client url %s is HTTP while client cert auth (--client-cert-auth) is enabled. Ignored client cert auth for this url.", u.String())
+				}
+			}
+		}
+		if (u.Scheme == "https" || u.Scheme == "unixs") && cfg.ClientTLSInfo.Empty() {
+			return nil, fmt.Errorf("TLS key/cert (--cert-file, --key-file) must be provided for client url %s with HTTPS scheme", u.String())
+		}
+
+		network := "tcp"
+		addr := u.Host
+		if u.Scheme == "unix" || u.Scheme == "unixs" {
+			network = "unix"
+			addr = u.Host + u.Path
+		}
+		sctx.network = network
+
+		sctx.secure = u.Scheme == "https" || u.Scheme == "unixs"
+		sctx.insecure = !sctx.secure
+		if oldctx := sctxs[addr]; oldctx != nil {
+			oldctx.secure = oldctx.secure || sctx.secure
+			oldctx.insecure = oldctx.insecure || sctx.insecure
+			continue
+		}
+
+		if sctx.l, err = net.Listen(network, addr); err != nil {
+			return nil, err
+		}
+		// net.Listener will rewrite ipv4 0.0.0.0 to ipv6 [::], breaking
+		// hosts that disable ipv6. So, use the address given by the user.
+		sctx.addr = addr
+
+		if fdLimit, fderr := runtimeutil.FDLimit(); fderr == nil {
+			if fdLimit <= reservedInternalFDNum {
+				if cfg.logger != nil {
+					cfg.logger.Fatal(
+						"file descriptor limit of etcd process is too low; please set higher",
+						zap.Uint64("limit", fdLimit),
+						zap.Int("recommended-limit", reservedInternalFDNum),
+					)
+				} else {
+					plog.Fatalf("file descriptor limit[%d] of etcd process is too low, and should be set higher than %d to ensure internal usage", fdLimit, reservedInternalFDNum)
+				}
+			}
+			sctx.l = transport.LimitListener(sctx.l, int(fdLimit-reservedInternalFDNum))
+		}
+
+		if network == "tcp" {
+			if sctx.l, err = transport.NewKeepAliveListener(sctx.l, network, nil); err != nil {
+				return nil, err
+			}
+		}
+
+		defer func() {
+			if err == nil {
+				return
+			}
+			sctx.l.Close()
+			if cfg.logger != nil {
+				cfg.logger.Warn(
+					"closing peer listener",
+					zap.String("address", u.Host),
+					zap.Error(err),
+				)
+			} else {
+				plog.Info("stopping listening for client requests on ", u.Host)
+			}
+		}()
+		for k := range cfg.UserHandlers {
+			sctx.userHandlers[k] = cfg.UserHandlers[k]
+		}
+		sctx.serviceRegister = cfg.ServiceRegister
+		if cfg.EnablePprof || cfg.Debug {
+			sctx.registerPprof()
+		}
+		if cfg.Debug {
+			sctx.registerTrace()
+		}
+		sctxs[addr] = sctx
+	}
+	return sctxs, nil
+}
+
+func (e *Etcd) serveClients() (err error) {
+	if !e.cfg.ClientTLSInfo.Empty() {
+		if e.cfg.logger != nil {
+			e.cfg.logger.Info(
+				"starting with client TLS",
+				zap.String("tls-info", fmt.Sprintf("%+v", e.cfg.ClientTLSInfo)),
+				zap.Strings("cipher-suites", e.cfg.CipherSuites),
+			)
+		} else {
+			plog.Infof("ClientTLS: %s", e.cfg.ClientTLSInfo)
+		}
+	}
+
+	// Start a client server goroutine for each listen address
+	var h http.Handler
+	if e.Config().EnableV2 {
+		if len(e.Config().ExperimentalEnableV2V3) > 0 {
+			srv := v2v3.NewServer(e.cfg.logger, v3client.New(e.Server), e.cfg.ExperimentalEnableV2V3)
+			h = v2http.NewClientHandler(e.GetLogger(), srv, e.Server.Cfg.ReqTimeout())
+		} else {
+			h = v2http.NewClientHandler(e.GetLogger(), e.Server, e.Server.Cfg.ReqTimeout())
+		}
+	} else {
+		mux := http.NewServeMux()
+		etcdhttp.HandleBasic(mux, e.Server)
+		h = mux
+	}
+
+	gopts := []grpc.ServerOption{}
+	if e.cfg.GRPCKeepAliveMinTime > time.Duration(0) {
+		gopts = append(gopts, grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{
+			MinTime:             e.cfg.GRPCKeepAliveMinTime,
+			PermitWithoutStream: false,
+		}))
+	}
+	if e.cfg.GRPCKeepAliveInterval > time.Duration(0) &&
+		e.cfg.GRPCKeepAliveTimeout > time.Duration(0) {
+		gopts = append(gopts, grpc.KeepaliveParams(keepalive.ServerParameters{
+			Time:    e.cfg.GRPCKeepAliveInterval,
+			Timeout: e.cfg.GRPCKeepAliveTimeout,
+		}))
+	}
+
+	// start client servers in each goroutine
+	for _, sctx := range e.sctxs {
+		go func(s *serveCtx) {
+			e.errHandler(s.serve(e.Server, &e.cfg.ClientTLSInfo, h, e.errHandler, gopts...))
+		}(sctx)
+	}
+	return nil
+}
+
+func (e *Etcd) serveMetrics() (err error) {
+	if e.cfg.Metrics == "extensive" {
+		grpc_prometheus.EnableHandlingTimeHistogram()
+	}
+
+	if len(e.cfg.ListenMetricsUrls) > 0 {
+		metricsMux := http.NewServeMux()
+		etcdhttp.HandleMetricsHealth(metricsMux, e.Server)
+
+		for _, murl := range e.cfg.ListenMetricsUrls {
+			tlsInfo := &e.cfg.ClientTLSInfo
+			if murl.Scheme == "http" {
+				tlsInfo = nil
+			}
+			ml, err := transport.NewListener(murl.Host, murl.Scheme, tlsInfo)
+			if err != nil {
+				return err
+			}
+			e.metricsListeners = append(e.metricsListeners, ml)
+			go func(u url.URL, ln net.Listener) {
+				if e.cfg.logger != nil {
+					e.cfg.logger.Info(
+						"serving metrics",
+						zap.String("address", u.String()),
+					)
+				} else {
+					plog.Info("listening for metrics on ", u.String())
+				}
+				e.errHandler(http.Serve(ln, metricsMux))
+			}(murl, ml)
+		}
+	}
+	return nil
+}
+
+func (e *Etcd) errHandler(err error) {
+	select {
+	case <-e.stopc:
+		return
+	default:
+	}
+	select {
+	case <-e.stopc:
+	case e.errc <- err:
+	}
+}
+
+// GetLogger returns the logger.
+func (e *Etcd) GetLogger() *zap.Logger {
+	e.cfg.loggerMu.RLock()
+	l := e.cfg.logger
+	e.cfg.loggerMu.RUnlock()
+	return l
+}
+
+func parseCompactionRetention(mode, retention string) (ret time.Duration, err error) {
+	h, err := strconv.Atoi(retention)
+	if err == nil {
+		switch mode {
+		case CompactorModeRevision:
+			ret = time.Duration(int64(h))
+		case CompactorModePeriodic:
+			ret = time.Duration(int64(h)) * time.Hour
+		}
+	} else {
+		// periodic compaction
+		ret, err = time.ParseDuration(retention)
+		if err != nil {
+			return 0, fmt.Errorf("error parsing CompactionRetention: %v", err)
+		}
+	}
+	return ret, nil
+}
diff --git a/vendor/go.etcd.io/etcd/embed/serve.go b/vendor/go.etcd.io/etcd/embed/serve.go
new file mode 100644
index 0000000..a3b20c4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/serve.go
@@ -0,0 +1,435 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embed
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	defaultLog "log"
+	"net"
+	"net/http"
+	"strings"
+
+	"go.etcd.io/etcd/clientv3/credentials"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3client"
+	"go.etcd.io/etcd/etcdserver/api/v3election"
+	"go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb"
+	v3electiongw "go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/gw"
+	"go.etcd.io/etcd/etcdserver/api/v3lock"
+	"go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb"
+	v3lockgw "go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/gw"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc"
+	etcdservergw "go.etcd.io/etcd/etcdserver/etcdserverpb/gw"
+	"go.etcd.io/etcd/pkg/debugutil"
+	"go.etcd.io/etcd/pkg/httputil"
+	"go.etcd.io/etcd/pkg/transport"
+
+	gw "github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/soheilhy/cmux"
+	"github.com/tmc/grpc-websocket-proxy/wsproxy"
+	"go.uber.org/zap"
+	"golang.org/x/net/trace"
+	"google.golang.org/grpc"
+)
+
+type serveCtx struct {
+	lg       *zap.Logger
+	l        net.Listener
+	addr     string
+	network  string
+	secure   bool
+	insecure bool
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	userHandlers    map[string]http.Handler
+	serviceRegister func(*grpc.Server)
+	serversC        chan *servers
+}
+
+type servers struct {
+	secure bool
+	grpc   *grpc.Server
+	http   *http.Server
+}
+
+func newServeCtx(lg *zap.Logger) *serveCtx {
+	ctx, cancel := context.WithCancel(context.Background())
+	return &serveCtx{
+		lg:           lg,
+		ctx:          ctx,
+		cancel:       cancel,
+		userHandlers: make(map[string]http.Handler),
+		serversC:     make(chan *servers, 2), // in case sctx.insecure,sctx.secure true
+	}
+}
+
+// serve accepts incoming connections on the listener l,
+// creating a new service goroutine for each. The service goroutines
+// read requests and then call handler to reply to them.
+func (sctx *serveCtx) serve(
+	s *etcdserver.EtcdServer,
+	tlsinfo *transport.TLSInfo,
+	handler http.Handler,
+	errHandler func(error),
+	gopts ...grpc.ServerOption) (err error) {
+	logger := defaultLog.New(ioutil.Discard, "etcdhttp", 0)
+	<-s.ReadyNotify()
+
+	if sctx.lg == nil {
+		plog.Info("ready to serve client requests")
+	}
+
+	m := cmux.New(sctx.l)
+	v3c := v3client.New(s)
+	servElection := v3election.NewElectionServer(v3c)
+	servLock := v3lock.NewLockServer(v3c)
+
+	var gs *grpc.Server
+	defer func() {
+		if err != nil && gs != nil {
+			gs.Stop()
+		}
+	}()
+
+	if sctx.insecure {
+		gs = v3rpc.Server(s, nil, gopts...)
+		v3electionpb.RegisterElectionServer(gs, servElection)
+		v3lockpb.RegisterLockServer(gs, servLock)
+		if sctx.serviceRegister != nil {
+			sctx.serviceRegister(gs)
+		}
+		grpcl := m.Match(cmux.HTTP2())
+		go func() { errHandler(gs.Serve(grpcl)) }()
+
+		var gwmux *gw.ServeMux
+		if s.Cfg.EnableGRPCGateway {
+			gwmux, err = sctx.registerGateway([]grpc.DialOption{grpc.WithInsecure()})
+			if err != nil {
+				return err
+			}
+		}
+
+		httpmux := sctx.createMux(gwmux, handler)
+
+		srvhttp := &http.Server{
+			Handler:  createAccessController(sctx.lg, s, httpmux),
+			ErrorLog: logger, // do not log user error
+		}
+		httpl := m.Match(cmux.HTTP1())
+		go func() { errHandler(srvhttp.Serve(httpl)) }()
+
+		sctx.serversC <- &servers{grpc: gs, http: srvhttp}
+		if sctx.lg != nil {
+			sctx.lg.Info(
+				"serving client traffic insecurely; this is strongly discouraged!",
+				zap.String("address", sctx.l.Addr().String()),
+			)
+		} else {
+			plog.Noticef("serving insecure client requests on %s, this is strongly discouraged!", sctx.l.Addr().String())
+		}
+	}
+
+	if sctx.secure {
+		tlscfg, tlsErr := tlsinfo.ServerConfig()
+		if tlsErr != nil {
+			return tlsErr
+		}
+		gs = v3rpc.Server(s, tlscfg, gopts...)
+		v3electionpb.RegisterElectionServer(gs, servElection)
+		v3lockpb.RegisterLockServer(gs, servLock)
+		if sctx.serviceRegister != nil {
+			sctx.serviceRegister(gs)
+		}
+		handler = grpcHandlerFunc(gs, handler)
+
+		var gwmux *gw.ServeMux
+		if s.Cfg.EnableGRPCGateway {
+			dtls := tlscfg.Clone()
+			// trust local server
+			dtls.InsecureSkipVerify = true
+			bundle := credentials.NewBundle(credentials.Config{TLSConfig: dtls})
+			opts := []grpc.DialOption{grpc.WithTransportCredentials(bundle.TransportCredentials())}
+			gwmux, err = sctx.registerGateway(opts)
+			if err != nil {
+				return err
+			}
+		}
+
+		var tlsl net.Listener
+		tlsl, err = transport.NewTLSListener(m.Match(cmux.Any()), tlsinfo)
+		if err != nil {
+			return err
+		}
+		// TODO: add debug flag; enable logging when debug flag is set
+		httpmux := sctx.createMux(gwmux, handler)
+
+		srv := &http.Server{
+			Handler:   createAccessController(sctx.lg, s, httpmux),
+			TLSConfig: tlscfg,
+			ErrorLog:  logger, // do not log user error
+		}
+		go func() { errHandler(srv.Serve(tlsl)) }()
+
+		sctx.serversC <- &servers{secure: true, grpc: gs, http: srv}
+		if sctx.lg != nil {
+			sctx.lg.Info(
+				"serving client traffic securely",
+				zap.String("address", sctx.l.Addr().String()),
+			)
+		} else {
+			plog.Infof("serving client requests on %s", sctx.l.Addr().String())
+		}
+	}
+
+	close(sctx.serversC)
+	return m.Serve()
+}
+
+// grpcHandlerFunc returns an http.Handler that delegates to grpcServer on incoming gRPC
+// connections or otherHandler otherwise. Given in gRPC docs.
+func grpcHandlerFunc(grpcServer *grpc.Server, otherHandler http.Handler) http.Handler {
+	if otherHandler == nil {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			grpcServer.ServeHTTP(w, r)
+		})
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.ProtoMajor == 2 && strings.Contains(r.Header.Get("Content-Type"), "application/grpc") {
+			grpcServer.ServeHTTP(w, r)
+		} else {
+			otherHandler.ServeHTTP(w, r)
+		}
+	})
+}
+
+type registerHandlerFunc func(context.Context, *gw.ServeMux, *grpc.ClientConn) error
+
+func (sctx *serveCtx) registerGateway(opts []grpc.DialOption) (*gw.ServeMux, error) {
+	ctx := sctx.ctx
+
+	addr := sctx.addr
+	if network := sctx.network; network == "unix" {
+		// explicitly define unix network for gRPC socket support
+		addr = fmt.Sprintf("%s://%s", network, addr)
+	}
+
+	conn, err := grpc.DialContext(ctx, addr, opts...)
+	if err != nil {
+		return nil, err
+	}
+	gwmux := gw.NewServeMux()
+
+	handlers := []registerHandlerFunc{
+		etcdservergw.RegisterKVHandler,
+		etcdservergw.RegisterWatchHandler,
+		etcdservergw.RegisterLeaseHandler,
+		etcdservergw.RegisterClusterHandler,
+		etcdservergw.RegisterMaintenanceHandler,
+		etcdservergw.RegisterAuthHandler,
+		v3lockgw.RegisterLockHandler,
+		v3electiongw.RegisterElectionHandler,
+	}
+	for _, h := range handlers {
+		if err := h(ctx, gwmux, conn); err != nil {
+			return nil, err
+		}
+	}
+	go func() {
+		<-ctx.Done()
+		if cerr := conn.Close(); cerr != nil {
+			if sctx.lg != nil {
+				sctx.lg.Warn(
+					"failed to close connection",
+					zap.String("address", sctx.l.Addr().String()),
+					zap.Error(cerr),
+				)
+			} else {
+				plog.Warningf("failed to close conn to %s: %v", sctx.l.Addr().String(), cerr)
+			}
+		}
+	}()
+
+	return gwmux, nil
+}
+
+func (sctx *serveCtx) createMux(gwmux *gw.ServeMux, handler http.Handler) *http.ServeMux {
+	httpmux := http.NewServeMux()
+	for path, h := range sctx.userHandlers {
+		httpmux.Handle(path, h)
+	}
+
+	if gwmux != nil {
+		httpmux.Handle(
+			"/v3/",
+			wsproxy.WebsocketProxy(
+				gwmux,
+				wsproxy.WithRequestMutator(
+					// Default to the POST method for streams
+					func(_ *http.Request, outgoing *http.Request) *http.Request {
+						outgoing.Method = "POST"
+						return outgoing
+					},
+				),
+			),
+		)
+	}
+	if handler != nil {
+		httpmux.Handle("/", handler)
+	}
+	return httpmux
+}
+
+// createAccessController wraps HTTP multiplexer:
+// - mutate gRPC gateway request paths
+// - check hostname whitelist
+// client HTTP requests goes here first
+func createAccessController(lg *zap.Logger, s *etcdserver.EtcdServer, mux *http.ServeMux) http.Handler {
+	return &accessController{lg: lg, s: s, mux: mux}
+}
+
+type accessController struct {
+	lg  *zap.Logger
+	s   *etcdserver.EtcdServer
+	mux *http.ServeMux
+}
+
+func (ac *accessController) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	// redirect for backward compatibilities
+	if req != nil && req.URL != nil && strings.HasPrefix(req.URL.Path, "/v3beta/") {
+		req.URL.Path = strings.Replace(req.URL.Path, "/v3beta/", "/v3/", 1)
+	}
+
+	if req.TLS == nil { // check origin if client connection is not secure
+		host := httputil.GetHostname(req)
+		if !ac.s.AccessController.IsHostWhitelisted(host) {
+			if ac.lg != nil {
+				ac.lg.Warn(
+					"rejecting HTTP request to prevent DNS rebinding attacks",
+					zap.String("host", host),
+				)
+			} else {
+				plog.Warningf("rejecting HTTP request from %q to prevent DNS rebinding attacks", host)
+			}
+			// TODO: use Go's "http.StatusMisdirectedRequest" (421)
+			// https://github.com/golang/go/commit/4b8a7eafef039af1834ef9bfa879257c4a72b7b5
+			http.Error(rw, errCVE20185702(host), 421)
+			return
+		}
+	} else if ac.s.Cfg.ClientCertAuthEnabled && ac.s.Cfg.EnableGRPCGateway &&
+		ac.s.AuthStore().IsAuthEnabled() && strings.HasPrefix(req.URL.Path, "/v3/") {
+		for _, chains := range req.TLS.VerifiedChains {
+			if len(chains) < 1 {
+				continue
+			}
+			if len(chains[0].Subject.CommonName) != 0 {
+				http.Error(rw, "CommonName of client sending a request against gateway will be ignored and not used as expected", 400)
+				return
+			}
+		}
+	}
+
+	// Write CORS header.
+	if ac.s.AccessController.OriginAllowed("*") {
+		addCORSHeader(rw, "*")
+	} else if origin := req.Header.Get("Origin"); ac.s.OriginAllowed(origin) {
+		addCORSHeader(rw, origin)
+	}
+
+	if req.Method == "OPTIONS" {
+		rw.WriteHeader(http.StatusOK)
+		return
+	}
+
+	ac.mux.ServeHTTP(rw, req)
+}
+
+// addCORSHeader adds the correct cors headers given an origin
+func addCORSHeader(w http.ResponseWriter, origin string) {
+	w.Header().Add("Access-Control-Allow-Methods", "POST, GET, OPTIONS, PUT, DELETE")
+	w.Header().Add("Access-Control-Allow-Origin", origin)
+	w.Header().Add("Access-Control-Allow-Headers", "accept, content-type, authorization")
+}
+
+// https://github.com/transmission/transmission/pull/468
+func errCVE20185702(host string) string {
+	return fmt.Sprintf(`
+etcd received your request, but the Host header was unrecognized.
+
+To fix this, choose one of the following options:
+- Enable TLS, then any HTTPS request will be allowed.
+- Add the hostname you want to use to the whitelist in settings.
+  - e.g. etcd --host-whitelist %q
+
+This requirement has been added to help prevent "DNS Rebinding" attacks (CVE-2018-5702).
+`, host)
+}
+
+// WrapCORS wraps existing handler with CORS.
+// TODO: deprecate this after v2 proxy deprecate
+func WrapCORS(cors map[string]struct{}, h http.Handler) http.Handler {
+	return &corsHandler{
+		ac: &etcdserver.AccessController{CORS: cors},
+		h:  h,
+	}
+}
+
+type corsHandler struct {
+	ac *etcdserver.AccessController
+	h  http.Handler
+}
+
+func (ch *corsHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	if ch.ac.OriginAllowed("*") {
+		addCORSHeader(rw, "*")
+	} else if origin := req.Header.Get("Origin"); ch.ac.OriginAllowed(origin) {
+		addCORSHeader(rw, origin)
+	}
+
+	if req.Method == "OPTIONS" {
+		rw.WriteHeader(http.StatusOK)
+		return
+	}
+
+	ch.h.ServeHTTP(rw, req)
+}
+
+func (sctx *serveCtx) registerUserHandler(s string, h http.Handler) {
+	if sctx.userHandlers[s] != nil {
+		if sctx.lg != nil {
+			sctx.lg.Warn("path is already registered by user handler", zap.String("path", s))
+		} else {
+			plog.Warningf("path %s already registered by user handler", s)
+		}
+		return
+	}
+	sctx.userHandlers[s] = h
+}
+
+func (sctx *serveCtx) registerPprof() {
+	for p, h := range debugutil.PProfHandlers() {
+		sctx.registerUserHandler(p, h)
+	}
+}
+
+func (sctx *serveCtx) registerTrace() {
+	reqf := func(w http.ResponseWriter, r *http.Request) { trace.Render(w, r, true) }
+	sctx.registerUserHandler("/debug/requests", http.HandlerFunc(reqf))
+	evf := func(w http.ResponseWriter, r *http.Request) { trace.RenderEvents(w, r, true) }
+	sctx.registerUserHandler("/debug/events", http.HandlerFunc(evf))
+}
diff --git a/vendor/go.etcd.io/etcd/embed/util.go b/vendor/go.etcd.io/etcd/embed/util.go
new file mode 100644
index 0000000..40f3ce9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/embed/util.go
@@ -0,0 +1,29 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package embed
+
+import (
+	"path/filepath"
+
+	"go.etcd.io/etcd/wal"
+)
+
+func isMemberInitialized(cfg *Config) bool {
+	waldir := cfg.WalDir
+	if waldir == "" {
+		waldir = filepath.Join(cfg.Dir, "member", "wal")
+	}
+	return wal.Exist(waldir)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/capability.go b/vendor/go.etcd.io/etcd/etcdserver/api/capability.go
new file mode 100644
index 0000000..09b754d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/capability.go
@@ -0,0 +1,99 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"sync"
+
+	"go.etcd.io/etcd/version"
+	"go.uber.org/zap"
+
+	"github.com/coreos/go-semver/semver"
+	"github.com/coreos/pkg/capnslog"
+)
+
+type Capability string
+
+const (
+	AuthCapability  Capability = "auth"
+	V3rpcCapability Capability = "v3rpc"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api")
+
+	// capabilityMaps is a static map of version to capability map.
+	capabilityMaps = map[string]map[Capability]bool{
+		"3.0.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.1.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.2.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.3.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.4.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.5.0": {AuthCapability: true, V3rpcCapability: true},
+	}
+
+	enableMapMu sync.RWMutex
+	// enabledMap points to a map in capabilityMaps
+	enabledMap map[Capability]bool
+
+	curVersion *semver.Version
+)
+
+func init() {
+	enabledMap = map[Capability]bool{
+		AuthCapability:  true,
+		V3rpcCapability: true,
+	}
+}
+
+// UpdateCapability updates the enabledMap when the cluster version increases.
+func UpdateCapability(lg *zap.Logger, v *semver.Version) {
+	if v == nil {
+		// if recovered but version was never set by cluster
+		return
+	}
+	enableMapMu.Lock()
+	if curVersion != nil && !curVersion.LessThan(*v) {
+		enableMapMu.Unlock()
+		return
+	}
+	curVersion = v
+	enabledMap = capabilityMaps[curVersion.String()]
+	enableMapMu.Unlock()
+
+	if lg != nil {
+		lg.Info(
+			"enabled capabilities for version",
+			zap.String("cluster-version", version.Cluster(v.String())),
+		)
+	} else {
+		plog.Infof("enabled capabilities for version %s", version.Cluster(v.String()))
+	}
+}
+
+func IsCapabilityEnabled(c Capability) bool {
+	enableMapMu.RLock()
+	defer enableMapMu.RUnlock()
+	if enabledMap == nil {
+		return false
+	}
+	return enabledMap[c]
+}
+
+func EnableCapability(c Capability) {
+	enableMapMu.Lock()
+	defer enableMapMu.Unlock()
+	enabledMap[c] = true
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go b/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go
new file mode 100644
index 0000000..901be9d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/cluster.go
@@ -0,0 +1,38 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package api
+
+import (
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+// Cluster is an interface representing a collection of members in one etcd cluster.
+type Cluster interface {
+	// ID returns the cluster ID
+	ID() types.ID
+	// ClientURLs returns an aggregate set of all URLs on which this
+	// cluster is listening for client requests
+	ClientURLs() []string
+	// Members returns a slice of members sorted by their ID
+	Members() []*membership.Member
+	// Member retrieves a particular member based on ID, or nil if the
+	// member does not exist in the cluster
+	Member(id types.ID) *membership.Member
+	// Version is the cluster-wide minimum major.minor version.
+	Version() *semver.Version
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/doc.go
new file mode 100644
index 0000000..f44881b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package api manages the capabilities and features that are exposed to clients by the etcd cluster.
+package api
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/base.go b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/base.go
new file mode 100644
index 0000000..c9df62e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/base.go
@@ -0,0 +1,203 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdhttp
+
+import (
+	"encoding/json"
+	"expvar"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+	"go.etcd.io/etcd/pkg/logutil"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api/etcdhttp")
+	mlog = logutil.NewMergeLogger(plog)
+)
+
+const (
+	configPath  = "/config"
+	varsPath    = "/debug/vars"
+	versionPath = "/version"
+)
+
+// HandleBasic adds handlers to a mux for serving JSON etcd client requests
+// that do not access the v2 store.
+func HandleBasic(mux *http.ServeMux, server etcdserver.ServerPeer) {
+	mux.HandleFunc(varsPath, serveVars)
+
+	// TODO: deprecate '/config/local/log' in v3.5
+	mux.HandleFunc(configPath+"/local/log", logHandleFunc)
+
+	HandleMetricsHealth(mux, server)
+	mux.HandleFunc(versionPath, versionHandler(server.Cluster(), serveVersion))
+}
+
+func versionHandler(c api.Cluster, fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		v := c.Version()
+		if v != nil {
+			fn(w, r, v.String())
+		} else {
+			fn(w, r, "not_decided")
+		}
+	}
+}
+
+func serveVersion(w http.ResponseWriter, r *http.Request, clusterV string) {
+	if !allowMethod(w, r, "GET") {
+		return
+	}
+	vs := version.Versions{
+		Server:  version.Version,
+		Cluster: clusterV,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	b, err := json.Marshal(&vs)
+	if err != nil {
+		plog.Panicf("cannot marshal versions to json (%v)", err)
+	}
+	w.Write(b)
+}
+
+// TODO: deprecate '/config/local/log' in v3.5
+func logHandleFunc(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r, "PUT") {
+		return
+	}
+
+	in := struct{ Level string }{}
+
+	d := json.NewDecoder(r.Body)
+	if err := d.Decode(&in); err != nil {
+		WriteError(nil, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid json body"))
+		return
+	}
+
+	logl, err := capnslog.ParseLevel(strings.ToUpper(in.Level))
+	if err != nil {
+		WriteError(nil, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid log level "+in.Level))
+		return
+	}
+
+	plog.Noticef("globalLogLevel set to %q", logl.String())
+	capnslog.SetGlobalLogLevel(logl)
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func serveVars(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r, "GET") {
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	fmt.Fprintf(w, "{\n")
+	first := true
+	expvar.Do(func(kv expvar.KeyValue) {
+		if !first {
+			fmt.Fprintf(w, ",\n")
+		}
+		first = false
+		fmt.Fprintf(w, "%q: %s", kv.Key, kv.Value)
+	})
+	fmt.Fprintf(w, "\n}\n")
+}
+
+func allowMethod(w http.ResponseWriter, r *http.Request, m string) bool {
+	if m == r.Method {
+		return true
+	}
+	w.Header().Set("Allow", m)
+	http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+	return false
+}
+
+// WriteError logs and writes the given Error to the ResponseWriter
+// If Error is an etcdErr, it is rendered to the ResponseWriter
+// Otherwise, it is assumed to be a StatusInternalServerError
+func WriteError(lg *zap.Logger, w http.ResponseWriter, r *http.Request, err error) {
+	if err == nil {
+		return
+	}
+	switch e := err.(type) {
+	case *v2error.Error:
+		e.WriteTo(w)
+
+	case *httptypes.HTTPError:
+		if et := e.WriteTo(w); et != nil {
+			if lg != nil {
+				lg.Debug(
+					"failed to write v2 HTTP error",
+					zap.String("remote-addr", r.RemoteAddr),
+					zap.String("internal-server-error", e.Error()),
+					zap.Error(et),
+				)
+			} else {
+				plog.Debugf("error writing HTTPError (%v) to %s", et, r.RemoteAddr)
+			}
+		}
+
+	default:
+		switch err {
+		case etcdserver.ErrTimeoutDueToLeaderFail, etcdserver.ErrTimeoutDueToConnectionLost, etcdserver.ErrNotEnoughStartedMembers,
+			etcdserver.ErrUnhealthy:
+			if lg != nil {
+				lg.Warn(
+					"v2 response error",
+					zap.String("remote-addr", r.RemoteAddr),
+					zap.String("internal-server-error", err.Error()),
+				)
+			} else {
+				mlog.MergeError(err)
+			}
+
+		default:
+			if lg != nil {
+				lg.Warn(
+					"unexpected v2 response error",
+					zap.String("remote-addr", r.RemoteAddr),
+					zap.String("internal-server-error", err.Error()),
+				)
+			} else {
+				mlog.MergeErrorf("got unexpected response error (%v)", err)
+			}
+		}
+
+		herr := httptypes.NewHTTPError(http.StatusInternalServerError, "Internal Server Error")
+		if et := herr.WriteTo(w); et != nil {
+			if lg != nil {
+				lg.Debug(
+					"failed to write v2 HTTP error",
+					zap.String("remote-addr", r.RemoteAddr),
+					zap.String("internal-server-error", err.Error()),
+					zap.Error(et),
+				)
+			} else {
+				plog.Debugf("error writing HTTPError (%v) to %s", et, r.RemoteAddr)
+			}
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/doc.go
new file mode 100644
index 0000000..a03b626
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package etcdhttp implements HTTP transportation layer for etcdserver.
+package etcdhttp
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go
new file mode 100644
index 0000000..f455e40
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/metrics.go
@@ -0,0 +1,123 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdhttp
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/raft"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+const (
+	PathMetrics = "/metrics"
+	PathHealth  = "/health"
+)
+
+// HandleMetricsHealth registers metrics and health handlers.
+func HandleMetricsHealth(mux *http.ServeMux, srv etcdserver.ServerV2) {
+	mux.Handle(PathMetrics, promhttp.Handler())
+	mux.Handle(PathHealth, NewHealthHandler(func() Health { return checkHealth(srv) }))
+}
+
+// HandlePrometheus registers prometheus handler on '/metrics'.
+func HandlePrometheus(mux *http.ServeMux) {
+	mux.Handle(PathMetrics, promhttp.Handler())
+}
+
+// NewHealthHandler handles '/health' requests.
+func NewHealthHandler(hfunc func() Health) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			w.Header().Set("Allow", http.MethodGet)
+			http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		h := hfunc()
+		d, _ := json.Marshal(h)
+		if h.Health != "true" {
+			http.Error(w, string(d), http.StatusServiceUnavailable)
+			return
+		}
+		w.WriteHeader(http.StatusOK)
+		w.Write(d)
+	}
+}
+
+var (
+	healthSuccess = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "health_success",
+		Help:      "The total number of successful health checks",
+	})
+	healthFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "health_failures",
+		Help:      "The total number of failed health checks",
+	})
+)
+
+func init() {
+	prometheus.MustRegister(healthSuccess)
+	prometheus.MustRegister(healthFailed)
+}
+
+// Health defines etcd server health status.
+// TODO: remove manual parsing in etcdctl cluster-health
+type Health struct {
+	Health string `json:"health"`
+}
+
+// TODO: server NOSPACE, etcdserver.ErrNoLeader in health API
+
+func checkHealth(srv etcdserver.ServerV2) Health {
+	h := Health{Health: "true"}
+
+	as := srv.Alarms()
+	if len(as) > 0 {
+		h.Health = "false"
+	}
+
+	if h.Health == "true" {
+		if uint64(srv.Leader()) == raft.None {
+			h.Health = "false"
+		}
+	}
+
+	if h.Health == "true" {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		_, err := srv.Do(ctx, etcdserverpb.Request{Method: "QGET"})
+		cancel()
+		if err != nil {
+			h.Health = "false"
+		}
+	}
+
+	if h.Health == "true" {
+		healthSuccess.Inc()
+	} else {
+		healthFailed.Inc()
+	}
+	return h
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/peer.go b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/peer.go
new file mode 100644
index 0000000..6c61bf5
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/etcdhttp/peer.go
@@ -0,0 +1,159 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdhttp
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
+	"go.etcd.io/etcd/lease/leasehttp"
+	"go.etcd.io/etcd/pkg/types"
+
+	"go.uber.org/zap"
+)
+
+const (
+	peerMembersPath         = "/members"
+	peerMemberPromotePrefix = "/members/promote/"
+)
+
+// NewPeerHandler generates an http.Handler to handle etcd peer requests.
+func NewPeerHandler(lg *zap.Logger, s etcdserver.ServerPeer) http.Handler {
+	return newPeerHandler(lg, s, s.RaftHandler(), s.LeaseHandler())
+}
+
+func newPeerHandler(lg *zap.Logger, s etcdserver.Server, raftHandler http.Handler, leaseHandler http.Handler) http.Handler {
+	peerMembersHandler := newPeerMembersHandler(lg, s.Cluster())
+	peerMemberPromoteHandler := newPeerMemberPromoteHandler(lg, s)
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/", http.NotFound)
+	mux.Handle(rafthttp.RaftPrefix, raftHandler)
+	mux.Handle(rafthttp.RaftPrefix+"/", raftHandler)
+	mux.Handle(peerMembersPath, peerMembersHandler)
+	mux.Handle(peerMemberPromotePrefix, peerMemberPromoteHandler)
+	if leaseHandler != nil {
+		mux.Handle(leasehttp.LeasePrefix, leaseHandler)
+		mux.Handle(leasehttp.LeaseInternalPrefix, leaseHandler)
+	}
+	mux.HandleFunc(versionPath, versionHandler(s.Cluster(), serveVersion))
+	return mux
+}
+
+func newPeerMembersHandler(lg *zap.Logger, cluster api.Cluster) http.Handler {
+	return &peerMembersHandler{
+		lg:      lg,
+		cluster: cluster,
+	}
+}
+
+type peerMembersHandler struct {
+	lg      *zap.Logger
+	cluster api.Cluster
+}
+
+func newPeerMemberPromoteHandler(lg *zap.Logger, s etcdserver.Server) http.Handler {
+	return &peerMemberPromoteHandler{
+		lg:      lg,
+		cluster: s.Cluster(),
+		server:  s,
+	}
+}
+
+type peerMemberPromoteHandler struct {
+	lg      *zap.Logger
+	cluster api.Cluster
+	server  etcdserver.Server
+}
+
+func (h *peerMembersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r, "GET") {
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
+
+	if r.URL.Path != peerMembersPath {
+		http.Error(w, "bad path", http.StatusBadRequest)
+		return
+	}
+	ms := h.cluster.Members()
+	w.Header().Set("Content-Type", "application/json")
+	if err := json.NewEncoder(w).Encode(ms); err != nil {
+		if h.lg != nil {
+			h.lg.Warn("failed to encode membership members", zap.Error(err))
+		} else {
+			plog.Warningf("failed to encode members response (%v)", err)
+		}
+	}
+}
+
+func (h *peerMemberPromoteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r, "POST") {
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
+
+	if !strings.HasPrefix(r.URL.Path, peerMemberPromotePrefix) {
+		http.Error(w, "bad path", http.StatusBadRequest)
+		return
+	}
+	idStr := strings.TrimPrefix(r.URL.Path, peerMemberPromotePrefix)
+	id, err := strconv.ParseUint(idStr, 10, 64)
+	if err != nil {
+		http.Error(w, fmt.Sprintf("member %s not found in cluster", idStr), http.StatusNotFound)
+		return
+	}
+
+	resp, err := h.server.PromoteMember(r.Context(), id)
+	if err != nil {
+		switch err {
+		case membership.ErrIDNotFound:
+			http.Error(w, err.Error(), http.StatusNotFound)
+		case membership.ErrMemberNotLearner:
+			http.Error(w, err.Error(), http.StatusPreconditionFailed)
+		case etcdserver.ErrLearnerNotReady:
+			http.Error(w, err.Error(), http.StatusPreconditionFailed)
+		default:
+			WriteError(h.lg, w, r, err)
+		}
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to promote a member",
+				zap.String("member-id", types.ID(id).String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("error promoting member %s (%v)", types.ID(id).String(), err)
+		}
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	if err := json.NewEncoder(w).Encode(resp); err != nil {
+		if h.lg != nil {
+			h.lg.Warn("failed to encode members response", zap.Error(err))
+		} else {
+			plog.Warningf("failed to encode members response (%v)", err)
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/cluster.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/cluster.go
new file mode 100644
index 0000000..89a6edd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/cluster.go
@@ -0,0 +1,841 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package membership
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha1"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"path"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/netutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/go-semver/semver"
+	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
+)
+
+const maxLearners = 1
+
+// RaftCluster is a list of Members that belong to the same raft cluster
+type RaftCluster struct {
+	lg *zap.Logger
+
+	localID types.ID
+	cid     types.ID
+	token   string
+
+	v2store v2store.Store
+	be      backend.Backend
+
+	sync.Mutex // guards the fields below
+	version    *semver.Version
+	members    map[types.ID]*Member
+	// removed contains the ids of removed members in the cluster.
+	// removed id cannot be reused.
+	removed map[types.ID]bool
+}
+
+// ConfigChangeContext represents a context for confChange.
+type ConfigChangeContext struct {
+	Member
+	// IsPromote indicates if the config change is for promoting a learner member.
+	// This flag is needed because both adding a new member and promoting a learner member
+	// uses the same config change type 'ConfChangeAddNode'.
+	IsPromote bool `json:"isPromote"`
+}
+
+// NewClusterFromURLsMap creates a new raft cluster using provided urls map. Currently, it does not support creating
+// cluster with raft learner member.
+func NewClusterFromURLsMap(lg *zap.Logger, token string, urlsmap types.URLsMap) (*RaftCluster, error) {
+	c := NewCluster(lg, token)
+	for name, urls := range urlsmap {
+		m := NewMember(name, urls, token, nil)
+		if _, ok := c.members[m.ID]; ok {
+			return nil, fmt.Errorf("member exists with identical ID %v", m)
+		}
+		if uint64(m.ID) == raft.None {
+			return nil, fmt.Errorf("cannot use %x as member id", raft.None)
+		}
+		c.members[m.ID] = m
+	}
+	c.genID()
+	return c, nil
+}
+
+func NewClusterFromMembers(lg *zap.Logger, token string, id types.ID, membs []*Member) *RaftCluster {
+	c := NewCluster(lg, token)
+	c.cid = id
+	for _, m := range membs {
+		c.members[m.ID] = m
+	}
+	return c
+}
+
+func NewCluster(lg *zap.Logger, token string) *RaftCluster {
+	return &RaftCluster{
+		lg:      lg,
+		token:   token,
+		members: make(map[types.ID]*Member),
+		removed: make(map[types.ID]bool),
+	}
+}
+
+func (c *RaftCluster) ID() types.ID { return c.cid }
+
+func (c *RaftCluster) Members() []*Member {
+	c.Lock()
+	defer c.Unlock()
+	var ms MembersByID
+	for _, m := range c.members {
+		ms = append(ms, m.Clone())
+	}
+	sort.Sort(ms)
+	return []*Member(ms)
+}
+
+func (c *RaftCluster) Member(id types.ID) *Member {
+	c.Lock()
+	defer c.Unlock()
+	return c.members[id].Clone()
+}
+
+func (c *RaftCluster) VotingMembers() []*Member {
+	c.Lock()
+	defer c.Unlock()
+	var ms MembersByID
+	for _, m := range c.members {
+		if !m.IsLearner {
+			ms = append(ms, m.Clone())
+		}
+	}
+	sort.Sort(ms)
+	return []*Member(ms)
+}
+
+// MemberByName returns a Member with the given name if exists.
+// If more than one member has the given name, it will panic.
+func (c *RaftCluster) MemberByName(name string) *Member {
+	c.Lock()
+	defer c.Unlock()
+	var memb *Member
+	for _, m := range c.members {
+		if m.Name == name {
+			if memb != nil {
+				if c.lg != nil {
+					c.lg.Panic("two member with same name found", zap.String("name", name))
+				} else {
+					plog.Panicf("two members with the given name %q exist", name)
+				}
+			}
+			memb = m
+		}
+	}
+	return memb.Clone()
+}
+
+func (c *RaftCluster) MemberIDs() []types.ID {
+	c.Lock()
+	defer c.Unlock()
+	var ids []types.ID
+	for _, m := range c.members {
+		ids = append(ids, m.ID)
+	}
+	sort.Sort(types.IDSlice(ids))
+	return ids
+}
+
+func (c *RaftCluster) IsIDRemoved(id types.ID) bool {
+	c.Lock()
+	defer c.Unlock()
+	return c.removed[id]
+}
+
+// PeerURLs returns a list of all peer addresses.
+// The returned list is sorted in ascending lexicographical order.
+func (c *RaftCluster) PeerURLs() []string {
+	c.Lock()
+	defer c.Unlock()
+	urls := make([]string, 0)
+	for _, p := range c.members {
+		urls = append(urls, p.PeerURLs...)
+	}
+	sort.Strings(urls)
+	return urls
+}
+
+// ClientURLs returns a list of all client addresses.
+// The returned list is sorted in ascending lexicographical order.
+func (c *RaftCluster) ClientURLs() []string {
+	c.Lock()
+	defer c.Unlock()
+	urls := make([]string, 0)
+	for _, p := range c.members {
+		urls = append(urls, p.ClientURLs...)
+	}
+	sort.Strings(urls)
+	return urls
+}
+
+func (c *RaftCluster) String() string {
+	c.Lock()
+	defer c.Unlock()
+	b := &bytes.Buffer{}
+	fmt.Fprintf(b, "{ClusterID:%s ", c.cid)
+	var ms []string
+	for _, m := range c.members {
+		ms = append(ms, fmt.Sprintf("%+v", m))
+	}
+	fmt.Fprintf(b, "Members:[%s] ", strings.Join(ms, " "))
+	var ids []string
+	for id := range c.removed {
+		ids = append(ids, id.String())
+	}
+	fmt.Fprintf(b, "RemovedMemberIDs:[%s]}", strings.Join(ids, " "))
+	return b.String()
+}
+
+func (c *RaftCluster) genID() {
+	mIDs := c.MemberIDs()
+	b := make([]byte, 8*len(mIDs))
+	for i, id := range mIDs {
+		binary.BigEndian.PutUint64(b[8*i:], uint64(id))
+	}
+	hash := sha1.Sum(b)
+	c.cid = types.ID(binary.BigEndian.Uint64(hash[:8]))
+}
+
+func (c *RaftCluster) SetID(localID, cid types.ID) {
+	c.localID = localID
+	c.cid = cid
+}
+
+func (c *RaftCluster) SetStore(st v2store.Store) { c.v2store = st }
+
+func (c *RaftCluster) SetBackend(be backend.Backend) {
+	c.be = be
+	mustCreateBackendBuckets(c.be)
+}
+
+func (c *RaftCluster) Recover(onSet func(*zap.Logger, *semver.Version)) {
+	c.Lock()
+	defer c.Unlock()
+
+	c.members, c.removed = membersFromStore(c.lg, c.v2store)
+	c.version = clusterVersionFromStore(c.lg, c.v2store)
+	mustDetectDowngrade(c.lg, c.version)
+	onSet(c.lg, c.version)
+
+	for _, m := range c.members {
+		if c.lg != nil {
+			c.lg.Info(
+				"recovered/added member from store",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("recovered-remote-peer-id", m.ID.String()),
+				zap.Strings("recovered-remote-peer-urls", m.PeerURLs),
+			)
+		} else {
+			plog.Infof("added member %s %v to cluster %s from store", m.ID, m.PeerURLs, c.cid)
+		}
+	}
+	if c.version != nil {
+		if c.lg != nil {
+			c.lg.Info(
+				"set cluster version from store",
+				zap.String("cluster-version", version.Cluster(c.version.String())),
+			)
+		} else {
+			plog.Infof("set the cluster version to %v from store", version.Cluster(c.version.String()))
+		}
+	}
+}
+
+// ValidateConfigurationChange takes a proposed ConfChange and
+// ensures that it is still valid.
+func (c *RaftCluster) ValidateConfigurationChange(cc raftpb.ConfChange) error {
+	members, removed := membersFromStore(c.lg, c.v2store)
+	id := types.ID(cc.NodeID)
+	if removed[id] {
+		return ErrIDRemoved
+	}
+	switch cc.Type {
+	case raftpb.ConfChangeAddNode, raftpb.ConfChangeAddLearnerNode:
+		confChangeContext := new(ConfigChangeContext)
+		if err := json.Unmarshal(cc.Context, confChangeContext); err != nil {
+			if c.lg != nil {
+				c.lg.Panic("failed to unmarshal confChangeContext", zap.Error(err))
+			} else {
+				plog.Panicf("unmarshal confChangeContext should never fail: %v", err)
+			}
+		}
+
+		if confChangeContext.IsPromote { // promoting a learner member to voting member
+			if members[id] == nil {
+				return ErrIDNotFound
+			}
+			if !members[id].IsLearner {
+				return ErrMemberNotLearner
+			}
+		} else { // adding a new member
+			if members[id] != nil {
+				return ErrIDExists
+			}
+
+			urls := make(map[string]bool)
+			for _, m := range members {
+				for _, u := range m.PeerURLs {
+					urls[u] = true
+				}
+			}
+			for _, u := range confChangeContext.Member.PeerURLs {
+				if urls[u] {
+					return ErrPeerURLexists
+				}
+			}
+
+			if confChangeContext.Member.IsLearner { // the new member is a learner
+				numLearners := 0
+				for _, m := range members {
+					if m.IsLearner {
+						numLearners++
+					}
+				}
+				if numLearners+1 > maxLearners {
+					return ErrTooManyLearners
+				}
+			}
+		}
+	case raftpb.ConfChangeRemoveNode:
+		if members[id] == nil {
+			return ErrIDNotFound
+		}
+
+	case raftpb.ConfChangeUpdateNode:
+		if members[id] == nil {
+			return ErrIDNotFound
+		}
+		urls := make(map[string]bool)
+		for _, m := range members {
+			if m.ID == id {
+				continue
+			}
+			for _, u := range m.PeerURLs {
+				urls[u] = true
+			}
+		}
+		m := new(Member)
+		if err := json.Unmarshal(cc.Context, m); err != nil {
+			if c.lg != nil {
+				c.lg.Panic("failed to unmarshal member", zap.Error(err))
+			} else {
+				plog.Panicf("unmarshal member should never fail: %v", err)
+			}
+		}
+		for _, u := range m.PeerURLs {
+			if urls[u] {
+				return ErrPeerURLexists
+			}
+		}
+
+	default:
+		if c.lg != nil {
+			c.lg.Panic("unknown ConfChange type", zap.String("type", cc.Type.String()))
+		} else {
+			plog.Panicf("ConfChange type should be either AddNode, RemoveNode or UpdateNode")
+		}
+	}
+	return nil
+}
+
+// AddMember adds a new Member into the cluster, and saves the given member's
+// raftAttributes into the store. The given member should have empty attributes.
+// A Member with a matching id must not exist.
+func (c *RaftCluster) AddMember(m *Member) {
+	c.Lock()
+	defer c.Unlock()
+	if c.v2store != nil {
+		mustSaveMemberToStore(c.v2store, m)
+	}
+	if c.be != nil {
+		mustSaveMemberToBackend(c.be, m)
+	}
+
+	c.members[m.ID] = m
+
+	if c.lg != nil {
+		c.lg.Info(
+			"added member",
+			zap.String("cluster-id", c.cid.String()),
+			zap.String("local-member-id", c.localID.String()),
+			zap.String("added-peer-id", m.ID.String()),
+			zap.Strings("added-peer-peer-urls", m.PeerURLs),
+		)
+	} else {
+		plog.Infof("added member %s %v to cluster %s", m.ID, m.PeerURLs, c.cid)
+	}
+}
+
+// RemoveMember removes a member from the store.
+// The given id MUST exist, or the function panics.
+func (c *RaftCluster) RemoveMember(id types.ID) {
+	c.Lock()
+	defer c.Unlock()
+	if c.v2store != nil {
+		mustDeleteMemberFromStore(c.v2store, id)
+	}
+	if c.be != nil {
+		mustDeleteMemberFromBackend(c.be, id)
+	}
+
+	m, ok := c.members[id]
+	delete(c.members, id)
+	c.removed[id] = true
+
+	if c.lg != nil {
+		if ok {
+			c.lg.Info(
+				"removed member",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("removed-remote-peer-id", id.String()),
+				zap.Strings("removed-remote-peer-urls", m.PeerURLs),
+			)
+		} else {
+			c.lg.Warn(
+				"skipped removing already removed member",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("removed-remote-peer-id", id.String()),
+			)
+		}
+	} else {
+		plog.Infof("removed member %s from cluster %s", id, c.cid)
+	}
+}
+
+func (c *RaftCluster) UpdateAttributes(id types.ID, attr Attributes) {
+	c.Lock()
+	defer c.Unlock()
+
+	if m, ok := c.members[id]; ok {
+		m.Attributes = attr
+		if c.v2store != nil {
+			mustUpdateMemberAttrInStore(c.v2store, m)
+		}
+		if c.be != nil {
+			mustSaveMemberToBackend(c.be, m)
+		}
+		return
+	}
+
+	_, ok := c.removed[id]
+	if !ok {
+		if c.lg != nil {
+			c.lg.Panic(
+				"failed to update; member unknown",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("unknown-remote-peer-id", id.String()),
+			)
+		} else {
+			plog.Panicf("error updating attributes of unknown member %s", id)
+		}
+	}
+
+	if c.lg != nil {
+		c.lg.Warn(
+			"skipped attributes update of removed member",
+			zap.String("cluster-id", c.cid.String()),
+			zap.String("local-member-id", c.localID.String()),
+			zap.String("updated-peer-id", id.String()),
+		)
+	} else {
+		plog.Warningf("skipped updating attributes of removed member %s", id)
+	}
+}
+
+// PromoteMember marks the member's IsLearner RaftAttributes to false.
+func (c *RaftCluster) PromoteMember(id types.ID) {
+	c.Lock()
+	defer c.Unlock()
+
+	c.members[id].RaftAttributes.IsLearner = false
+	if c.v2store != nil {
+		mustUpdateMemberInStore(c.v2store, c.members[id])
+	}
+	if c.be != nil {
+		mustSaveMemberToBackend(c.be, c.members[id])
+	}
+
+	if c.lg != nil {
+		c.lg.Info(
+			"promote member",
+			zap.String("cluster-id", c.cid.String()),
+			zap.String("local-member-id", c.localID.String()),
+		)
+	} else {
+		plog.Noticef("promote member %s in cluster %s", id, c.cid)
+	}
+}
+
+func (c *RaftCluster) UpdateRaftAttributes(id types.ID, raftAttr RaftAttributes) {
+	c.Lock()
+	defer c.Unlock()
+
+	c.members[id].RaftAttributes = raftAttr
+	if c.v2store != nil {
+		mustUpdateMemberInStore(c.v2store, c.members[id])
+	}
+	if c.be != nil {
+		mustSaveMemberToBackend(c.be, c.members[id])
+	}
+
+	if c.lg != nil {
+		c.lg.Info(
+			"updated member",
+			zap.String("cluster-id", c.cid.String()),
+			zap.String("local-member-id", c.localID.String()),
+			zap.String("updated-remote-peer-id", id.String()),
+			zap.Strings("updated-remote-peer-urls", raftAttr.PeerURLs),
+		)
+	} else {
+		plog.Noticef("updated member %s %v in cluster %s", id, raftAttr.PeerURLs, c.cid)
+	}
+}
+
+func (c *RaftCluster) Version() *semver.Version {
+	c.Lock()
+	defer c.Unlock()
+	if c.version == nil {
+		return nil
+	}
+	return semver.Must(semver.NewVersion(c.version.String()))
+}
+
+func (c *RaftCluster) SetVersion(ver *semver.Version, onSet func(*zap.Logger, *semver.Version)) {
+	c.Lock()
+	defer c.Unlock()
+	if c.version != nil {
+		if c.lg != nil {
+			c.lg.Info(
+				"updated cluster version",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("from", version.Cluster(c.version.String())),
+				zap.String("from", version.Cluster(ver.String())),
+			)
+		} else {
+			plog.Noticef("updated the cluster version from %v to %v", version.Cluster(c.version.String()), version.Cluster(ver.String()))
+		}
+	} else {
+		if c.lg != nil {
+			c.lg.Info(
+				"set initial cluster version",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+				zap.String("cluster-version", version.Cluster(ver.String())),
+			)
+		} else {
+			plog.Noticef("set the initial cluster version to %v", version.Cluster(ver.String()))
+		}
+	}
+	c.version = ver
+	mustDetectDowngrade(c.lg, c.version)
+	if c.v2store != nil {
+		mustSaveClusterVersionToStore(c.v2store, ver)
+	}
+	if c.be != nil {
+		mustSaveClusterVersionToBackend(c.be, ver)
+	}
+	ClusterVersionMetrics.With(prometheus.Labels{"cluster_version": ver.String()}).Set(1)
+	onSet(c.lg, ver)
+}
+
+func (c *RaftCluster) IsReadyToAddVotingMember() bool {
+	nmembers := 1
+	nstarted := 0
+
+	for _, member := range c.VotingMembers() {
+		if member.IsStarted() {
+			nstarted++
+		}
+		nmembers++
+	}
+
+	if nstarted == 1 && nmembers == 2 {
+		// a case of adding a new node to 1-member cluster for restoring cluster data
+		// https://github.com/etcd-io/etcd/blob/master/Documentation/v2/admin_guide.md#restoring-the-cluster
+		if c.lg != nil {
+			c.lg.Debug("number of started member is 1; can accept add member request")
+		} else {
+			plog.Debugf("The number of started member is 1. This cluster can accept add member request.")
+		}
+		return true
+	}
+
+	nquorum := nmembers/2 + 1
+	if nstarted < nquorum {
+		if c.lg != nil {
+			c.lg.Warn(
+				"rejecting member add; started member will be less than quorum",
+				zap.Int("number-of-started-member", nstarted),
+				zap.Int("quorum", nquorum),
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+			)
+		} else {
+			plog.Warningf("Reject add member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
+		}
+		return false
+	}
+
+	return true
+}
+
+func (c *RaftCluster) IsReadyToRemoveVotingMember(id uint64) bool {
+	nmembers := 0
+	nstarted := 0
+
+	for _, member := range c.VotingMembers() {
+		if uint64(member.ID) == id {
+			continue
+		}
+
+		if member.IsStarted() {
+			nstarted++
+		}
+		nmembers++
+	}
+
+	nquorum := nmembers/2 + 1
+	if nstarted < nquorum {
+		if c.lg != nil {
+			c.lg.Warn(
+				"rejecting member remove; started member will be less than quorum",
+				zap.Int("number-of-started-member", nstarted),
+				zap.Int("quorum", nquorum),
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+			)
+		} else {
+			plog.Warningf("Reject remove member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
+		}
+		return false
+	}
+
+	return true
+}
+
+func (c *RaftCluster) IsReadyToPromoteMember(id uint64) bool {
+	nmembers := 1
+	nstarted := 0
+
+	for _, member := range c.VotingMembers() {
+		if member.IsStarted() {
+			nstarted++
+		}
+		nmembers++
+	}
+
+	nquorum := nmembers/2 + 1
+	if nstarted < nquorum {
+		if c.lg != nil {
+			c.lg.Warn(
+				"rejecting member promote; started member will be less than quorum",
+				zap.Int("number-of-started-member", nstarted),
+				zap.Int("quorum", nquorum),
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+			)
+		} else {
+			plog.Warningf("Reject promote member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
+		}
+		return false
+	}
+
+	return true
+}
+
+func membersFromStore(lg *zap.Logger, st v2store.Store) (map[types.ID]*Member, map[types.ID]bool) {
+	members := make(map[types.ID]*Member)
+	removed := make(map[types.ID]bool)
+	e, err := st.Get(StoreMembersPrefix, true, true)
+	if err != nil {
+		if isKeyNotFound(err) {
+			return members, removed
+		}
+		if lg != nil {
+			lg.Panic("failed to get members from store", zap.String("path", StoreMembersPrefix), zap.Error(err))
+		} else {
+			plog.Panicf("get storeMembers should never fail: %v", err)
+		}
+	}
+	for _, n := range e.Node.Nodes {
+		var m *Member
+		m, err = nodeToMember(n)
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to nodeToMember", zap.Error(err))
+			} else {
+				plog.Panicf("nodeToMember should never fail: %v", err)
+			}
+		}
+		members[m.ID] = m
+	}
+
+	e, err = st.Get(storeRemovedMembersPrefix, true, true)
+	if err != nil {
+		if isKeyNotFound(err) {
+			return members, removed
+		}
+		if lg != nil {
+			lg.Panic(
+				"failed to get removed members from store",
+				zap.String("path", storeRemovedMembersPrefix),
+				zap.Error(err),
+			)
+		} else {
+			plog.Panicf("get storeRemovedMembers should never fail: %v", err)
+		}
+	}
+	for _, n := range e.Node.Nodes {
+		removed[MustParseMemberIDFromKey(n.Key)] = true
+	}
+	return members, removed
+}
+
+func clusterVersionFromStore(lg *zap.Logger, st v2store.Store) *semver.Version {
+	e, err := st.Get(path.Join(storePrefix, "version"), false, false)
+	if err != nil {
+		if isKeyNotFound(err) {
+			return nil
+		}
+		if lg != nil {
+			lg.Panic(
+				"failed to get cluster version from store",
+				zap.String("path", path.Join(storePrefix, "version")),
+				zap.Error(err),
+			)
+		} else {
+			plog.Panicf("unexpected error (%v) when getting cluster version from store", err)
+		}
+	}
+	return semver.Must(semver.NewVersion(*e.Node.Value))
+}
+
+// ValidateClusterAndAssignIDs validates the local cluster by matching the PeerURLs
+// with the existing cluster. If the validation succeeds, it assigns the IDs
+// from the existing cluster to the local cluster.
+// If the validation fails, an error will be returned.
+func ValidateClusterAndAssignIDs(lg *zap.Logger, local *RaftCluster, existing *RaftCluster) error {
+	ems := existing.Members()
+	lms := local.Members()
+	if len(ems) != len(lms) {
+		return fmt.Errorf("member count is unequal")
+	}
+
+	ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
+	defer cancel()
+	for i := range ems {
+		var err error
+		ok := false
+		for j := range lms {
+			if ok, err = netutil.URLStringsEqual(ctx, lg, ems[i].PeerURLs, lms[j].PeerURLs); ok {
+				lms[j].ID = ems[i].ID
+				break
+			}
+		}
+		if !ok {
+			return fmt.Errorf("PeerURLs: no match found for existing member (%v, %v), last resolver error (%v)", ems[i].ID, ems[i].PeerURLs, err)
+		}
+	}
+	local.members = make(map[types.ID]*Member)
+	for _, m := range lms {
+		local.members[m.ID] = m
+	}
+	return nil
+}
+
+func mustDetectDowngrade(lg *zap.Logger, cv *semver.Version) {
+	lv := semver.Must(semver.NewVersion(version.Version))
+	// only keep major.minor version for comparison against cluster version
+	lv = &semver.Version{Major: lv.Major, Minor: lv.Minor}
+	if cv != nil && lv.LessThan(*cv) {
+		if lg != nil {
+			lg.Fatal(
+				"invalid downgrade; server version is lower than determined cluster version",
+				zap.String("current-server-version", version.Version),
+				zap.String("determined-cluster-version", version.Cluster(cv.String())),
+			)
+		} else {
+			plog.Fatalf("cluster cannot be downgraded (current version: %s is lower than determined cluster version: %s).", version.Version, version.Cluster(cv.String()))
+		}
+	}
+}
+
+// IsLocalMemberLearner returns if the local member is raft learner
+func (c *RaftCluster) IsLocalMemberLearner() bool {
+	c.Lock()
+	defer c.Unlock()
+	localMember, ok := c.members[c.localID]
+	if !ok {
+		if c.lg != nil {
+			c.lg.Panic(
+				"failed to find local ID in cluster members",
+				zap.String("cluster-id", c.cid.String()),
+				zap.String("local-member-id", c.localID.String()),
+			)
+		} else {
+			plog.Panicf("failed to find local ID %s in cluster %s", c.localID.String(), c.cid.String())
+		}
+	}
+	return localMember.IsLearner
+}
+
+// IsMemberExist returns if the member with the given id exists in cluster.
+func (c *RaftCluster) IsMemberExist(id types.ID) bool {
+	c.Lock()
+	defer c.Unlock()
+	_, ok := c.members[id]
+	return ok
+}
+
+// VotingMemberIDs returns the ID of voting members in cluster.
+func (c *RaftCluster) VotingMemberIDs() []types.ID {
+	c.Lock()
+	defer c.Unlock()
+	var ids []types.ID
+	for _, m := range c.members {
+		if !m.IsLearner {
+			ids = append(ids, m.ID)
+		}
+	}
+	sort.Sort(types.IDSlice(ids))
+	return ids
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/doc.go
new file mode 100644
index 0000000..b07fb2d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package membership describes individual etcd members and clusters of members.
+package membership
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go
new file mode 100644
index 0000000..8f6fe50
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/errors.go
@@ -0,0 +1,35 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package membership
+
+import (
+	"errors"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+)
+
+var (
+	ErrIDRemoved        = errors.New("membership: ID removed")
+	ErrIDExists         = errors.New("membership: ID exists")
+	ErrIDNotFound       = errors.New("membership: ID not found")
+	ErrPeerURLexists    = errors.New("membership: peerURL exists")
+	ErrMemberNotLearner = errors.New("membership: can only promote a learner member")
+	ErrTooManyLearners  = errors.New("membership: too many learner members in cluster")
+)
+
+func isKeyNotFound(err error) bool {
+	e, ok := err.(*v2error.Error)
+	return ok && e.ErrorCode == v2error.EcodeKeyNotFound
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/member.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/member.go
new file mode 100644
index 0000000..896cb36
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/member.go
@@ -0,0 +1,142 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package membership
+
+import (
+	"crypto/sha1"
+	"encoding/binary"
+	"fmt"
+	"math/rand"
+	"sort"
+	"time"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.etcd.io/etcd/pkg/types"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd/v3", "etcdserver/membership")
+)
+
+// RaftAttributes represents the raft related attributes of an etcd member.
+type RaftAttributes struct {
+	// PeerURLs is the list of peers in the raft cluster.
+	// TODO(philips): ensure these are URLs
+	PeerURLs []string `json:"peerURLs"`
+	// IsLearner indicates if the member is raft learner.
+	IsLearner bool `json:"isLearner,omitempty"`
+}
+
+// Attributes represents all the non-raft related attributes of an etcd member.
+type Attributes struct {
+	Name       string   `json:"name,omitempty"`
+	ClientURLs []string `json:"clientURLs,omitempty"`
+}
+
+type Member struct {
+	ID types.ID `json:"id"`
+	RaftAttributes
+	Attributes
+}
+
+// NewMember creates a Member without an ID and generates one based on the
+// cluster name, peer URLs, and time. This is used for bootstrapping/adding new member.
+func NewMember(name string, peerURLs types.URLs, clusterName string, now *time.Time) *Member {
+	return newMember(name, peerURLs, clusterName, now, false)
+}
+
+// NewMemberAsLearner creates a learner Member without an ID and generates one based on the
+// cluster name, peer URLs, and time. This is used for adding new learner member.
+func NewMemberAsLearner(name string, peerURLs types.URLs, clusterName string, now *time.Time) *Member {
+	return newMember(name, peerURLs, clusterName, now, true)
+}
+
+func newMember(name string, peerURLs types.URLs, clusterName string, now *time.Time, isLearner bool) *Member {
+	m := &Member{
+		RaftAttributes: RaftAttributes{
+			PeerURLs:  peerURLs.StringSlice(),
+			IsLearner: isLearner,
+		},
+		Attributes: Attributes{Name: name},
+	}
+
+	var b []byte
+	sort.Strings(m.PeerURLs)
+	for _, p := range m.PeerURLs {
+		b = append(b, []byte(p)...)
+	}
+
+	b = append(b, []byte(clusterName)...)
+	if now != nil {
+		b = append(b, []byte(fmt.Sprintf("%d", now.Unix()))...)
+	}
+
+	hash := sha1.Sum(b)
+	m.ID = types.ID(binary.BigEndian.Uint64(hash[:8]))
+	return m
+}
+
+// PickPeerURL chooses a random address from a given Member's PeerURLs.
+// It will panic if there is no PeerURLs available in Member.
+func (m *Member) PickPeerURL() string {
+	if len(m.PeerURLs) == 0 {
+		panic("member should always have some peer url")
+	}
+	return m.PeerURLs[rand.Intn(len(m.PeerURLs))]
+}
+
+func (m *Member) Clone() *Member {
+	if m == nil {
+		return nil
+	}
+	mm := &Member{
+		ID: m.ID,
+		RaftAttributes: RaftAttributes{
+			IsLearner: m.IsLearner,
+		},
+		Attributes: Attributes{
+			Name: m.Name,
+		},
+	}
+	if m.PeerURLs != nil {
+		mm.PeerURLs = make([]string, len(m.PeerURLs))
+		copy(mm.PeerURLs, m.PeerURLs)
+	}
+	if m.ClientURLs != nil {
+		mm.ClientURLs = make([]string, len(m.ClientURLs))
+		copy(mm.ClientURLs, m.ClientURLs)
+	}
+	return mm
+}
+
+func (m *Member) IsStarted() bool {
+	return len(m.Name) != 0
+}
+
+// MembersByID implements sort by ID interface
+type MembersByID []*Member
+
+func (ms MembersByID) Len() int           { return len(ms) }
+func (ms MembersByID) Less(i, j int) bool { return ms[i].ID < ms[j].ID }
+func (ms MembersByID) Swap(i, j int)      { ms[i], ms[j] = ms[j], ms[i] }
+
+// MembersByPeerURLs implements sort by peer urls interface
+type MembersByPeerURLs []*Member
+
+func (ms MembersByPeerURLs) Len() int { return len(ms) }
+func (ms MembersByPeerURLs) Less(i, j int) bool {
+	return ms[i].PeerURLs[0] < ms[j].PeerURLs[0]
+}
+func (ms MembersByPeerURLs) Swap(i, j int) { ms[i], ms[j] = ms[j], ms[i] }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/metrics.go
new file mode 100644
index 0000000..b3212bc
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/metrics.go
@@ -0,0 +1,31 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package membership
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	ClusterVersionMetrics = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "cluster",
+		Name:      "version",
+		Help:      "Which version is running. 1 for 'cluster_version' label with current cluster version",
+	},
+		[]string{"cluster_version"})
+)
+
+func init() {
+	prometheus.MustRegister(ClusterVersionMetrics)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/membership/store.go b/vendor/go.etcd.io/etcd/etcdserver/api/membership/store.go
new file mode 100644
index 0000000..14ab119
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/membership/store.go
@@ -0,0 +1,193 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package membership
+
+import (
+	"encoding/json"
+	"fmt"
+	"path"
+
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+const (
+	attributesSuffix     = "attributes"
+	raftAttributesSuffix = "raftAttributes"
+
+	// the prefix for stroing membership related information in store provided by store pkg.
+	storePrefix = "/0"
+)
+
+var (
+	membersBucketName        = []byte("members")
+	membersRemovedBucketName = []byte("members_removed")
+	clusterBucketName        = []byte("cluster")
+
+	StoreMembersPrefix        = path.Join(storePrefix, "members")
+	storeRemovedMembersPrefix = path.Join(storePrefix, "removed_members")
+)
+
+func mustSaveMemberToBackend(be backend.Backend, m *Member) {
+	mkey := backendMemberKey(m.ID)
+	mvalue, err := json.Marshal(m)
+	if err != nil {
+		plog.Panicf("marshal raftAttributes should never fail: %v", err)
+	}
+
+	tx := be.BatchTx()
+	tx.Lock()
+	tx.UnsafePut(membersBucketName, mkey, mvalue)
+	tx.Unlock()
+}
+
+func mustDeleteMemberFromBackend(be backend.Backend, id types.ID) {
+	mkey := backendMemberKey(id)
+
+	tx := be.BatchTx()
+	tx.Lock()
+	tx.UnsafeDelete(membersBucketName, mkey)
+	tx.UnsafePut(membersRemovedBucketName, mkey, []byte("removed"))
+	tx.Unlock()
+}
+
+func mustSaveClusterVersionToBackend(be backend.Backend, ver *semver.Version) {
+	ckey := backendClusterVersionKey()
+
+	tx := be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+	tx.UnsafePut(clusterBucketName, ckey, []byte(ver.String()))
+}
+
+func mustSaveMemberToStore(s v2store.Store, m *Member) {
+	b, err := json.Marshal(m.RaftAttributes)
+	if err != nil {
+		plog.Panicf("marshal raftAttributes should never fail: %v", err)
+	}
+	p := path.Join(MemberStoreKey(m.ID), raftAttributesSuffix)
+	if _, err := s.Create(p, false, string(b), false, v2store.TTLOptionSet{ExpireTime: v2store.Permanent}); err != nil {
+		plog.Panicf("create raftAttributes should never fail: %v", err)
+	}
+}
+
+func mustDeleteMemberFromStore(s v2store.Store, id types.ID) {
+	if _, err := s.Delete(MemberStoreKey(id), true, true); err != nil {
+		plog.Panicf("delete member should never fail: %v", err)
+	}
+	if _, err := s.Create(RemovedMemberStoreKey(id), false, "", false, v2store.TTLOptionSet{ExpireTime: v2store.Permanent}); err != nil {
+		plog.Panicf("create removedMember should never fail: %v", err)
+	}
+}
+
+func mustUpdateMemberInStore(s v2store.Store, m *Member) {
+	b, err := json.Marshal(m.RaftAttributes)
+	if err != nil {
+		plog.Panicf("marshal raftAttributes should never fail: %v", err)
+	}
+	p := path.Join(MemberStoreKey(m.ID), raftAttributesSuffix)
+	if _, err := s.Update(p, string(b), v2store.TTLOptionSet{ExpireTime: v2store.Permanent}); err != nil {
+		plog.Panicf("update raftAttributes should never fail: %v", err)
+	}
+}
+
+func mustUpdateMemberAttrInStore(s v2store.Store, m *Member) {
+	b, err := json.Marshal(m.Attributes)
+	if err != nil {
+		plog.Panicf("marshal raftAttributes should never fail: %v", err)
+	}
+	p := path.Join(MemberStoreKey(m.ID), attributesSuffix)
+	if _, err := s.Set(p, false, string(b), v2store.TTLOptionSet{ExpireTime: v2store.Permanent}); err != nil {
+		plog.Panicf("update raftAttributes should never fail: %v", err)
+	}
+}
+
+func mustSaveClusterVersionToStore(s v2store.Store, ver *semver.Version) {
+	if _, err := s.Set(StoreClusterVersionKey(), false, ver.String(), v2store.TTLOptionSet{ExpireTime: v2store.Permanent}); err != nil {
+		plog.Panicf("save cluster version should never fail: %v", err)
+	}
+}
+
+// nodeToMember builds member from a key value node.
+// the child nodes of the given node MUST be sorted by key.
+func nodeToMember(n *v2store.NodeExtern) (*Member, error) {
+	m := &Member{ID: MustParseMemberIDFromKey(n.Key)}
+	attrs := make(map[string][]byte)
+	raftAttrKey := path.Join(n.Key, raftAttributesSuffix)
+	attrKey := path.Join(n.Key, attributesSuffix)
+	for _, nn := range n.Nodes {
+		if nn.Key != raftAttrKey && nn.Key != attrKey {
+			return nil, fmt.Errorf("unknown key %q", nn.Key)
+		}
+		attrs[nn.Key] = []byte(*nn.Value)
+	}
+	if data := attrs[raftAttrKey]; data != nil {
+		if err := json.Unmarshal(data, &m.RaftAttributes); err != nil {
+			return nil, fmt.Errorf("unmarshal raftAttributes error: %v", err)
+		}
+	} else {
+		return nil, fmt.Errorf("raftAttributes key doesn't exist")
+	}
+	if data := attrs[attrKey]; data != nil {
+		if err := json.Unmarshal(data, &m.Attributes); err != nil {
+			return m, fmt.Errorf("unmarshal attributes error: %v", err)
+		}
+	}
+	return m, nil
+}
+
+func backendMemberKey(id types.ID) []byte {
+	return []byte(id.String())
+}
+
+func backendClusterVersionKey() []byte {
+	return []byte("clusterVersion")
+}
+
+func mustCreateBackendBuckets(be backend.Backend) {
+	tx := be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+	tx.UnsafeCreateBucket(membersBucketName)
+	tx.UnsafeCreateBucket(membersRemovedBucketName)
+	tx.UnsafeCreateBucket(clusterBucketName)
+}
+
+func MemberStoreKey(id types.ID) string {
+	return path.Join(StoreMembersPrefix, id.String())
+}
+
+func StoreClusterVersionKey() string {
+	return path.Join(storePrefix, "version")
+}
+
+func MemberAttributesStorePath(id types.ID) string {
+	return path.Join(MemberStoreKey(id), attributesSuffix)
+}
+
+func MustParseMemberIDFromKey(key string) types.ID {
+	id, err := types.IDFromString(path.Base(key))
+	if err != nil {
+		plog.Panicf("unexpected parse member id error: %v", err)
+	}
+	return id
+}
+
+func RemovedMemberStoreKey(id types.ID) string {
+	return path.Join(storeRemovedMembersPrefix, id.String())
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/coder.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/coder.go
new file mode 100644
index 0000000..12c3e44
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/coder.go
@@ -0,0 +1,27 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import "go.etcd.io/etcd/raft/raftpb"
+
+type encoder interface {
+	// encode encodes the given message to an output stream.
+	encode(m *raftpb.Message) error
+}
+
+type decoder interface {
+	// decode decodes the message from an input stream.
+	decode() (raftpb.Message, error)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/doc.go
new file mode 100644
index 0000000..a9486a8
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package rafthttp implements HTTP transportation layer for etcd/raft pkg.
+package rafthttp
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/http.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/http.go
new file mode 100644
index 0000000..d0e0c81
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/http.go
@@ -0,0 +1,577 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"path"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	pioutil "go.etcd.io/etcd/pkg/ioutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/version"
+
+	humanize "github.com/dustin/go-humanize"
+	"go.uber.org/zap"
+)
+
+const (
+	// connReadLimitByte limits the number of bytes
+	// a single read can read out.
+	//
+	// 64KB should be large enough for not causing
+	// throughput bottleneck as well as small enough
+	// for not causing a read timeout.
+	connReadLimitByte = 64 * 1024
+)
+
+var (
+	RaftPrefix         = "/raft"
+	ProbingPrefix      = path.Join(RaftPrefix, "probing")
+	RaftStreamPrefix   = path.Join(RaftPrefix, "stream")
+	RaftSnapshotPrefix = path.Join(RaftPrefix, "snapshot")
+
+	errIncompatibleVersion = errors.New("incompatible version")
+	errClusterIDMismatch   = errors.New("cluster ID mismatch")
+)
+
+type peerGetter interface {
+	Get(id types.ID) Peer
+}
+
+type writerToResponse interface {
+	WriteTo(w http.ResponseWriter)
+}
+
+type pipelineHandler struct {
+	lg      *zap.Logger
+	localID types.ID
+	tr      Transporter
+	r       Raft
+	cid     types.ID
+}
+
+// newPipelineHandler returns a handler for handling raft messages
+// from pipeline for RaftPrefix.
+//
+// The handler reads out the raft message from request body,
+// and forwards it to the given raft state machine for processing.
+func newPipelineHandler(t *Transport, r Raft, cid types.ID) http.Handler {
+	return &pipelineHandler{
+		lg:      t.Logger,
+		localID: t.ID,
+		tr:      t,
+		r:       r,
+		cid:     cid,
+	}
+}
+
+func (h *pipelineHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		w.Header().Set("Allow", "POST")
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	w.Header().Set("X-Etcd-Cluster-ID", h.cid.String())
+
+	if err := checkClusterCompatibilityFromHeader(h.lg, h.localID, r.Header, h.cid); err != nil {
+		http.Error(w, err.Error(), http.StatusPreconditionFailed)
+		return
+	}
+
+	addRemoteFromRequest(h.tr, r)
+
+	// Limit the data size that could be read from the request body, which ensures that read from
+	// connection will not time out accidentally due to possible blocking in underlying implementation.
+	limitedr := pioutil.NewLimitedBufferReader(r.Body, connReadLimitByte)
+	b, err := ioutil.ReadAll(limitedr)
+	if err != nil {
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to read Raft message",
+				zap.String("local-member-id", h.localID.String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to read raft message (%v)", err)
+		}
+		http.Error(w, "error reading raft message", http.StatusBadRequest)
+		recvFailures.WithLabelValues(r.RemoteAddr).Inc()
+		return
+	}
+
+	var m raftpb.Message
+	if err := m.Unmarshal(b); err != nil {
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to unmarshal Raft message",
+				zap.String("local-member-id", h.localID.String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to unmarshal raft message (%v)", err)
+		}
+		http.Error(w, "error unmarshalling raft message", http.StatusBadRequest)
+		recvFailures.WithLabelValues(r.RemoteAddr).Inc()
+		return
+	}
+
+	receivedBytes.WithLabelValues(types.ID(m.From).String()).Add(float64(len(b)))
+
+	if err := h.r.Process(context.TODO(), m); err != nil {
+		switch v := err.(type) {
+		case writerToResponse:
+			v.WriteTo(w)
+		default:
+			if h.lg != nil {
+				h.lg.Warn(
+					"failed to process Raft message",
+					zap.String("local-member-id", h.localID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("failed to process raft message (%v)", err)
+			}
+			http.Error(w, "error processing raft message", http.StatusInternalServerError)
+			w.(http.Flusher).Flush()
+			// disconnect the http stream
+			panic(err)
+		}
+		return
+	}
+
+	// Write StatusNoContent header after the message has been processed by
+	// raft, which facilitates the client to report MsgSnap status.
+	w.WriteHeader(http.StatusNoContent)
+}
+
+type snapshotHandler struct {
+	lg          *zap.Logger
+	tr          Transporter
+	r           Raft
+	snapshotter *snap.Snapshotter
+
+	localID types.ID
+	cid     types.ID
+}
+
+func newSnapshotHandler(t *Transport, r Raft, snapshotter *snap.Snapshotter, cid types.ID) http.Handler {
+	return &snapshotHandler{
+		lg:          t.Logger,
+		tr:          t,
+		r:           r,
+		snapshotter: snapshotter,
+		localID:     t.ID,
+		cid:         cid,
+	}
+}
+
+const unknownSnapshotSender = "UNKNOWN_SNAPSHOT_SENDER"
+
+// ServeHTTP serves HTTP request to receive and process snapshot message.
+//
+// If request sender dies without closing underlying TCP connection,
+// the handler will keep waiting for the request body until TCP keepalive
+// finds out that the connection is broken after several minutes.
+// This is acceptable because
+// 1. snapshot messages sent through other TCP connections could still be
+// received and processed.
+// 2. this case should happen rarely, so no further optimization is done.
+func (h *snapshotHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	start := time.Now()
+
+	if r.Method != "POST" {
+		w.Header().Set("Allow", "POST")
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		snapshotReceiveFailures.WithLabelValues(unknownSnapshotSender).Inc()
+		return
+	}
+
+	w.Header().Set("X-Etcd-Cluster-ID", h.cid.String())
+
+	if err := checkClusterCompatibilityFromHeader(h.lg, h.localID, r.Header, h.cid); err != nil {
+		http.Error(w, err.Error(), http.StatusPreconditionFailed)
+		snapshotReceiveFailures.WithLabelValues(unknownSnapshotSender).Inc()
+		return
+	}
+
+	addRemoteFromRequest(h.tr, r)
+
+	dec := &messageDecoder{r: r.Body}
+	// let snapshots be very large since they can exceed 512MB for large installations
+	m, err := dec.decodeLimit(uint64(1 << 63))
+	from := types.ID(m.From).String()
+	if err != nil {
+		msg := fmt.Sprintf("failed to decode raft message (%v)", err)
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to decode Raft message",
+				zap.String("local-member-id", h.localID.String()),
+				zap.String("remote-snapshot-sender-id", from),
+				zap.Error(err),
+			)
+		} else {
+			plog.Error(msg)
+		}
+		http.Error(w, msg, http.StatusBadRequest)
+		recvFailures.WithLabelValues(r.RemoteAddr).Inc()
+		snapshotReceiveFailures.WithLabelValues(from).Inc()
+		return
+	}
+
+	msgSize := m.Size()
+	receivedBytes.WithLabelValues(from).Add(float64(msgSize))
+
+	if m.Type != raftpb.MsgSnap {
+		if h.lg != nil {
+			h.lg.Warn(
+				"unexpected Raft message type",
+				zap.String("local-member-id", h.localID.String()),
+				zap.String("remote-snapshot-sender-id", from),
+				zap.String("message-type", m.Type.String()),
+			)
+		} else {
+			plog.Errorf("unexpected raft message type %s on snapshot path", m.Type)
+		}
+		http.Error(w, "wrong raft message type", http.StatusBadRequest)
+		snapshotReceiveFailures.WithLabelValues(from).Inc()
+		return
+	}
+
+	snapshotReceiveInflights.WithLabelValues(from).Inc()
+	defer func() {
+		snapshotReceiveInflights.WithLabelValues(from).Dec()
+	}()
+
+	if h.lg != nil {
+		h.lg.Info(
+			"receiving database snapshot",
+			zap.String("local-member-id", h.localID.String()),
+			zap.String("remote-snapshot-sender-id", from),
+			zap.Uint64("incoming-snapshot-index", m.Snapshot.Metadata.Index),
+			zap.Int("incoming-snapshot-message-size-bytes", msgSize),
+			zap.String("incoming-snapshot-message-size", humanize.Bytes(uint64(msgSize))),
+		)
+	} else {
+		plog.Infof("receiving database snapshot [index:%d, from %s] ...", m.Snapshot.Metadata.Index, types.ID(m.From))
+	}
+
+	// save incoming database snapshot.
+	n, err := h.snapshotter.SaveDBFrom(r.Body, m.Snapshot.Metadata.Index)
+	if err != nil {
+		msg := fmt.Sprintf("failed to save KV snapshot (%v)", err)
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to save incoming database snapshot",
+				zap.String("local-member-id", h.localID.String()),
+				zap.String("remote-snapshot-sender-id", from),
+				zap.Uint64("incoming-snapshot-index", m.Snapshot.Metadata.Index),
+				zap.Error(err),
+			)
+		} else {
+			plog.Error(msg)
+		}
+		http.Error(w, msg, http.StatusInternalServerError)
+		snapshotReceiveFailures.WithLabelValues(from).Inc()
+		return
+	}
+
+	receivedBytes.WithLabelValues(from).Add(float64(n))
+
+	if h.lg != nil {
+		h.lg.Info(
+			"received and saved database snapshot",
+			zap.String("local-member-id", h.localID.String()),
+			zap.String("remote-snapshot-sender-id", from),
+			zap.Uint64("incoming-snapshot-index", m.Snapshot.Metadata.Index),
+			zap.Int64("incoming-snapshot-size-bytes", n),
+			zap.String("incoming-snapshot-size", humanize.Bytes(uint64(n))),
+		)
+	} else {
+		plog.Infof("received and saved database snapshot [index: %d, from: %s] successfully", m.Snapshot.Metadata.Index, types.ID(m.From))
+	}
+
+	if err := h.r.Process(context.TODO(), m); err != nil {
+		switch v := err.(type) {
+		// Process may return writerToResponse error when doing some
+		// additional checks before calling raft.Node.Step.
+		case writerToResponse:
+			v.WriteTo(w)
+		default:
+			msg := fmt.Sprintf("failed to process raft message (%v)", err)
+			if h.lg != nil {
+				h.lg.Warn(
+					"failed to process Raft message",
+					zap.String("local-member-id", h.localID.String()),
+					zap.String("remote-snapshot-sender-id", from),
+					zap.Error(err),
+				)
+			} else {
+				plog.Error(msg)
+			}
+			http.Error(w, msg, http.StatusInternalServerError)
+			snapshotReceiveFailures.WithLabelValues(from).Inc()
+		}
+		return
+	}
+
+	// Write StatusNoContent header after the message has been processed by
+	// raft, which facilitates the client to report MsgSnap status.
+	w.WriteHeader(http.StatusNoContent)
+
+	snapshotReceive.WithLabelValues(from).Inc()
+	snapshotReceiveSeconds.WithLabelValues(from).Observe(time.Since(start).Seconds())
+}
+
+type streamHandler struct {
+	lg         *zap.Logger
+	tr         *Transport
+	peerGetter peerGetter
+	r          Raft
+	id         types.ID
+	cid        types.ID
+}
+
+func newStreamHandler(t *Transport, pg peerGetter, r Raft, id, cid types.ID) http.Handler {
+	return &streamHandler{
+		lg:         t.Logger,
+		tr:         t,
+		peerGetter: pg,
+		r:          r,
+		id:         id,
+		cid:        cid,
+	}
+}
+
+func (h *streamHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" {
+		w.Header().Set("Allow", "GET")
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	w.Header().Set("X-Server-Version", version.Version)
+	w.Header().Set("X-Etcd-Cluster-ID", h.cid.String())
+
+	if err := checkClusterCompatibilityFromHeader(h.lg, h.tr.ID, r.Header, h.cid); err != nil {
+		http.Error(w, err.Error(), http.StatusPreconditionFailed)
+		return
+	}
+
+	var t streamType
+	switch path.Dir(r.URL.Path) {
+	case streamTypeMsgAppV2.endpoint():
+		t = streamTypeMsgAppV2
+	case streamTypeMessage.endpoint():
+		t = streamTypeMessage
+	default:
+		if h.lg != nil {
+			h.lg.Debug(
+				"ignored unexpected streaming request path",
+				zap.String("local-member-id", h.tr.ID.String()),
+				zap.String("remote-peer-id-stream-handler", h.id.String()),
+				zap.String("path", r.URL.Path),
+			)
+		} else {
+			plog.Debugf("ignored unexpected streaming request path %s", r.URL.Path)
+		}
+		http.Error(w, "invalid path", http.StatusNotFound)
+		return
+	}
+
+	fromStr := path.Base(r.URL.Path)
+	from, err := types.IDFromString(fromStr)
+	if err != nil {
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to parse path into ID",
+				zap.String("local-member-id", h.tr.ID.String()),
+				zap.String("remote-peer-id-stream-handler", h.id.String()),
+				zap.String("path", fromStr),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to parse from %s into ID (%v)", fromStr, err)
+		}
+		http.Error(w, "invalid from", http.StatusNotFound)
+		return
+	}
+	if h.r.IsIDRemoved(uint64(from)) {
+		if h.lg != nil {
+			h.lg.Warn(
+				"rejected stream from remote peer because it was removed",
+				zap.String("local-member-id", h.tr.ID.String()),
+				zap.String("remote-peer-id-stream-handler", h.id.String()),
+				zap.String("remote-peer-id-from", from.String()),
+			)
+		} else {
+			plog.Warningf("rejected the stream from peer %s since it was removed", from)
+		}
+		http.Error(w, "removed member", http.StatusGone)
+		return
+	}
+	p := h.peerGetter.Get(from)
+	if p == nil {
+		// This may happen in following cases:
+		// 1. user starts a remote peer that belongs to a different cluster
+		// with the same cluster ID.
+		// 2. local etcd falls behind of the cluster, and cannot recognize
+		// the members that joined after its current progress.
+		if urls := r.Header.Get("X-PeerURLs"); urls != "" {
+			h.tr.AddRemote(from, strings.Split(urls, ","))
+		}
+		if h.lg != nil {
+			h.lg.Warn(
+				"failed to find remote peer in cluster",
+				zap.String("local-member-id", h.tr.ID.String()),
+				zap.String("remote-peer-id-stream-handler", h.id.String()),
+				zap.String("remote-peer-id-from", from.String()),
+				zap.String("cluster-id", h.cid.String()),
+			)
+		} else {
+			plog.Errorf("failed to find member %s in cluster %s", from, h.cid)
+		}
+		http.Error(w, "error sender not found", http.StatusNotFound)
+		return
+	}
+
+	wto := h.id.String()
+	if gto := r.Header.Get("X-Raft-To"); gto != wto {
+		if h.lg != nil {
+			h.lg.Warn(
+				"ignored streaming request; ID mismatch",
+				zap.String("local-member-id", h.tr.ID.String()),
+				zap.String("remote-peer-id-stream-handler", h.id.String()),
+				zap.String("remote-peer-id-header", gto),
+				zap.String("remote-peer-id-from", from.String()),
+				zap.String("cluster-id", h.cid.String()),
+			)
+		} else {
+			plog.Errorf("streaming request ignored (ID mismatch got %s want %s)", gto, wto)
+		}
+		http.Error(w, "to field mismatch", http.StatusPreconditionFailed)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	w.(http.Flusher).Flush()
+
+	c := newCloseNotifier()
+	conn := &outgoingConn{
+		t:       t,
+		Writer:  w,
+		Flusher: w.(http.Flusher),
+		Closer:  c,
+		localID: h.tr.ID,
+		peerID:  h.id,
+	}
+	p.attachOutgoingConn(conn)
+	<-c.closeNotify()
+}
+
+// checkClusterCompatibilityFromHeader checks the cluster compatibility of
+// the local member from the given header.
+// It checks whether the version of local member is compatible with
+// the versions in the header, and whether the cluster ID of local member
+// matches the one in the header.
+func checkClusterCompatibilityFromHeader(lg *zap.Logger, localID types.ID, header http.Header, cid types.ID) error {
+	remoteName := header.Get("X-Server-From")
+
+	remoteServer := serverVersion(header)
+	remoteVs := ""
+	if remoteServer != nil {
+		remoteVs = remoteServer.String()
+	}
+
+	remoteMinClusterVer := minClusterVersion(header)
+	remoteMinClusterVs := ""
+	if remoteMinClusterVer != nil {
+		remoteMinClusterVs = remoteMinClusterVer.String()
+	}
+
+	localServer, localMinCluster, err := checkVersionCompatibility(remoteName, remoteServer, remoteMinClusterVer)
+
+	localVs := ""
+	if localServer != nil {
+		localVs = localServer.String()
+	}
+	localMinClusterVs := ""
+	if localMinCluster != nil {
+		localMinClusterVs = localMinCluster.String()
+	}
+
+	if err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to check version compatibility",
+				zap.String("local-member-id", localID.String()),
+				zap.String("local-member-cluster-id", cid.String()),
+				zap.String("local-member-server-version", localVs),
+				zap.String("local-member-server-minimum-cluster-version", localMinClusterVs),
+				zap.String("remote-peer-server-name", remoteName),
+				zap.String("remote-peer-server-version", remoteVs),
+				zap.String("remote-peer-server-minimum-cluster-version", remoteMinClusterVs),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("request version incompatibility (%v)", err)
+		}
+		return errIncompatibleVersion
+	}
+	if gcid := header.Get("X-Etcd-Cluster-ID"); gcid != cid.String() {
+		if lg != nil {
+			lg.Warn(
+				"request cluster ID mismatch",
+				zap.String("local-member-id", localID.String()),
+				zap.String("local-member-cluster-id", cid.String()),
+				zap.String("local-member-server-version", localVs),
+				zap.String("local-member-server-minimum-cluster-version", localMinClusterVs),
+				zap.String("remote-peer-server-name", remoteName),
+				zap.String("remote-peer-server-version", remoteVs),
+				zap.String("remote-peer-server-minimum-cluster-version", remoteMinClusterVs),
+				zap.String("remote-peer-cluster-id", gcid),
+			)
+		} else {
+			plog.Errorf("request cluster ID mismatch (got %s want %s)", gcid, cid)
+		}
+		return errClusterIDMismatch
+	}
+	return nil
+}
+
+type closeNotifier struct {
+	done chan struct{}
+}
+
+func newCloseNotifier() *closeNotifier {
+	return &closeNotifier{
+		done: make(chan struct{}),
+	}
+}
+
+func (n *closeNotifier) Close() error {
+	close(n.done)
+	return nil
+}
+
+func (n *closeNotifier) closeNotify() <-chan struct{} { return n.done }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/metrics.go
new file mode 100644
index 0000000..02fff84
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/metrics.go
@@ -0,0 +1,186 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	activePeers = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "active_peers",
+		Help:      "The current number of active peer connections.",
+	},
+		[]string{"Local", "Remote"},
+	)
+
+	disconnectedPeers = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "disconnected_peers_total",
+		Help:      "The total number of disconnected peers.",
+	},
+		[]string{"Local", "Remote"},
+	)
+
+	sentBytes = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "peer_sent_bytes_total",
+		Help:      "The total number of bytes sent to peers.",
+	},
+		[]string{"To"},
+	)
+
+	receivedBytes = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "peer_received_bytes_total",
+		Help:      "The total number of bytes received from peers.",
+	},
+		[]string{"From"},
+	)
+
+	sentFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "peer_sent_failures_total",
+		Help:      "The total number of send failures from peers.",
+	},
+		[]string{"To"},
+	)
+
+	recvFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "peer_received_failures_total",
+		Help:      "The total number of receive failures from peers.",
+	},
+		[]string{"From"},
+	)
+
+	snapshotSend = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_send_success",
+		Help:      "Total number of successful snapshot sends",
+	},
+		[]string{"To"},
+	)
+
+	snapshotSendInflights = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_send_inflights_total",
+		Help:      "Total number of inflight snapshot sends",
+	},
+		[]string{"To"},
+	)
+
+	snapshotSendFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_send_failures",
+		Help:      "Total number of snapshot send failures",
+	},
+		[]string{"To"},
+	)
+
+	snapshotSendSeconds = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_send_total_duration_seconds",
+		Help:      "Total latency distributions of v3 snapshot sends",
+
+		// lowest bucket start of upper bound 0.1 sec (100 ms) with factor 2
+		// highest bucket start of 0.1 sec * 2^9 == 51.2 sec
+		Buckets: prometheus.ExponentialBuckets(0.1, 2, 10),
+	},
+		[]string{"To"},
+	)
+
+	snapshotReceive = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_receive_success",
+		Help:      "Total number of successful snapshot receives",
+	},
+		[]string{"From"},
+	)
+
+	snapshotReceiveInflights = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_receive_inflights_total",
+		Help:      "Total number of inflight snapshot receives",
+	},
+		[]string{"From"},
+	)
+
+	snapshotReceiveFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_receive_failures",
+		Help:      "Total number of snapshot receive failures",
+	},
+		[]string{"From"},
+	)
+
+	snapshotReceiveSeconds = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_receive_total_duration_seconds",
+		Help:      "Total latency distributions of v3 snapshot receives",
+
+		// lowest bucket start of upper bound 0.1 sec (100 ms) with factor 2
+		// highest bucket start of 0.1 sec * 2^9 == 51.2 sec
+		Buckets: prometheus.ExponentialBuckets(0.1, 2, 10),
+	},
+		[]string{"From"},
+	)
+
+	rttSec = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "peer_round_trip_time_seconds",
+		Help:      "Round-Trip-Time histogram between peers",
+
+		// lowest bucket start of upper bound 0.0001 sec (0.1 ms) with factor 2
+		// highest bucket start of 0.0001 sec * 2^15 == 3.2768 sec
+		Buckets: prometheus.ExponentialBuckets(0.0001, 2, 16),
+	},
+		[]string{"To"},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(activePeers)
+	prometheus.MustRegister(disconnectedPeers)
+	prometheus.MustRegister(sentBytes)
+	prometheus.MustRegister(receivedBytes)
+	prometheus.MustRegister(sentFailures)
+	prometheus.MustRegister(recvFailures)
+
+	prometheus.MustRegister(snapshotSend)
+	prometheus.MustRegister(snapshotSendInflights)
+	prometheus.MustRegister(snapshotSendFailures)
+	prometheus.MustRegister(snapshotSendSeconds)
+	prometheus.MustRegister(snapshotReceive)
+	prometheus.MustRegister(snapshotReceiveInflights)
+	prometheus.MustRegister(snapshotReceiveFailures)
+	prometheus.MustRegister(snapshotReceiveSeconds)
+
+	prometheus.MustRegister(rttSec)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go
new file mode 100644
index 0000000..2417d22
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msg_codec.go
@@ -0,0 +1,68 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/raft/raftpb"
+)
+
+// messageEncoder is a encoder that can encode all kinds of messages.
+// It MUST be used with a paired messageDecoder.
+type messageEncoder struct {
+	w io.Writer
+}
+
+func (enc *messageEncoder) encode(m *raftpb.Message) error {
+	if err := binary.Write(enc.w, binary.BigEndian, uint64(m.Size())); err != nil {
+		return err
+	}
+	_, err := enc.w.Write(pbutil.MustMarshal(m))
+	return err
+}
+
+// messageDecoder is a decoder that can decode all kinds of messages.
+type messageDecoder struct {
+	r io.Reader
+}
+
+var (
+	readBytesLimit     uint64 = 512 * 1024 * 1024 // 512 MB
+	ErrExceedSizeLimit        = errors.New("rafthttp: error limit exceeded")
+)
+
+func (dec *messageDecoder) decode() (raftpb.Message, error) {
+	return dec.decodeLimit(readBytesLimit)
+}
+
+func (dec *messageDecoder) decodeLimit(numBytes uint64) (raftpb.Message, error) {
+	var m raftpb.Message
+	var l uint64
+	if err := binary.Read(dec.r, binary.BigEndian, &l); err != nil {
+		return m, err
+	}
+	if l > numBytes {
+		return m, ErrExceedSizeLimit
+	}
+	buf := make([]byte, int(l))
+	if _, err := io.ReadFull(dec.r, buf); err != nil {
+		return m, err
+	}
+	return m, m.Unmarshal(buf)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msgappv2_codec.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msgappv2_codec.go
new file mode 100644
index 0000000..1fa36de
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/msgappv2_codec.go
@@ -0,0 +1,248 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"time"
+
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+)
+
+const (
+	msgTypeLinkHeartbeat uint8 = 0
+	msgTypeAppEntries    uint8 = 1
+	msgTypeApp           uint8 = 2
+
+	msgAppV2BufSize = 1024 * 1024
+)
+
+// msgappv2 stream sends three types of message: linkHeartbeatMessage,
+// AppEntries and MsgApp. AppEntries is the MsgApp that is sent in
+// replicate state in raft, whose index and term are fully predictable.
+//
+// Data format of linkHeartbeatMessage:
+// | offset | bytes | description |
+// +--------+-------+-------------+
+// | 0      | 1     | \x00        |
+//
+// Data format of AppEntries:
+// | offset | bytes | description |
+// +--------+-------+-------------+
+// | 0      | 1     | \x01        |
+// | 1      | 8     | length of entries |
+// | 9      | 8     | length of first entry |
+// | 17     | n1    | first entry |
+// ...
+// | x      | 8     | length of k-th entry data |
+// | x+8    | nk    | k-th entry data |
+// | x+8+nk | 8     | commit index |
+//
+// Data format of MsgApp:
+// | offset | bytes | description |
+// +--------+-------+-------------+
+// | 0      | 1     | \x02        |
+// | 1      | 8     | length of encoded message |
+// | 9      | n     | encoded message |
+type msgAppV2Encoder struct {
+	w  io.Writer
+	fs *stats.FollowerStats
+
+	term      uint64
+	index     uint64
+	buf       []byte
+	uint64buf []byte
+	uint8buf  []byte
+}
+
+func newMsgAppV2Encoder(w io.Writer, fs *stats.FollowerStats) *msgAppV2Encoder {
+	return &msgAppV2Encoder{
+		w:         w,
+		fs:        fs,
+		buf:       make([]byte, msgAppV2BufSize),
+		uint64buf: make([]byte, 8),
+		uint8buf:  make([]byte, 1),
+	}
+}
+
+func (enc *msgAppV2Encoder) encode(m *raftpb.Message) error {
+	start := time.Now()
+	switch {
+	case isLinkHeartbeatMessage(m):
+		enc.uint8buf[0] = msgTypeLinkHeartbeat
+		if _, err := enc.w.Write(enc.uint8buf); err != nil {
+			return err
+		}
+	case enc.index == m.Index && enc.term == m.LogTerm && m.LogTerm == m.Term:
+		enc.uint8buf[0] = msgTypeAppEntries
+		if _, err := enc.w.Write(enc.uint8buf); err != nil {
+			return err
+		}
+		// write length of entries
+		binary.BigEndian.PutUint64(enc.uint64buf, uint64(len(m.Entries)))
+		if _, err := enc.w.Write(enc.uint64buf); err != nil {
+			return err
+		}
+		for i := 0; i < len(m.Entries); i++ {
+			// write length of entry
+			binary.BigEndian.PutUint64(enc.uint64buf, uint64(m.Entries[i].Size()))
+			if _, err := enc.w.Write(enc.uint64buf); err != nil {
+				return err
+			}
+			if n := m.Entries[i].Size(); n < msgAppV2BufSize {
+				if _, err := m.Entries[i].MarshalTo(enc.buf); err != nil {
+					return err
+				}
+				if _, err := enc.w.Write(enc.buf[:n]); err != nil {
+					return err
+				}
+			} else {
+				if _, err := enc.w.Write(pbutil.MustMarshal(&m.Entries[i])); err != nil {
+					return err
+				}
+			}
+			enc.index++
+		}
+		// write commit index
+		binary.BigEndian.PutUint64(enc.uint64buf, m.Commit)
+		if _, err := enc.w.Write(enc.uint64buf); err != nil {
+			return err
+		}
+		enc.fs.Succ(time.Since(start))
+	default:
+		if err := binary.Write(enc.w, binary.BigEndian, msgTypeApp); err != nil {
+			return err
+		}
+		// write size of message
+		if err := binary.Write(enc.w, binary.BigEndian, uint64(m.Size())); err != nil {
+			return err
+		}
+		// write message
+		if _, err := enc.w.Write(pbutil.MustMarshal(m)); err != nil {
+			return err
+		}
+
+		enc.term = m.Term
+		enc.index = m.Index
+		if l := len(m.Entries); l > 0 {
+			enc.index = m.Entries[l-1].Index
+		}
+		enc.fs.Succ(time.Since(start))
+	}
+	return nil
+}
+
+type msgAppV2Decoder struct {
+	r             io.Reader
+	local, remote types.ID
+
+	term      uint64
+	index     uint64
+	buf       []byte
+	uint64buf []byte
+	uint8buf  []byte
+}
+
+func newMsgAppV2Decoder(r io.Reader, local, remote types.ID) *msgAppV2Decoder {
+	return &msgAppV2Decoder{
+		r:         r,
+		local:     local,
+		remote:    remote,
+		buf:       make([]byte, msgAppV2BufSize),
+		uint64buf: make([]byte, 8),
+		uint8buf:  make([]byte, 1),
+	}
+}
+
+func (dec *msgAppV2Decoder) decode() (raftpb.Message, error) {
+	var (
+		m   raftpb.Message
+		typ uint8
+	)
+	if _, err := io.ReadFull(dec.r, dec.uint8buf); err != nil {
+		return m, err
+	}
+	typ = dec.uint8buf[0]
+	switch typ {
+	case msgTypeLinkHeartbeat:
+		return linkHeartbeatMessage, nil
+	case msgTypeAppEntries:
+		m = raftpb.Message{
+			Type:    raftpb.MsgApp,
+			From:    uint64(dec.remote),
+			To:      uint64(dec.local),
+			Term:    dec.term,
+			LogTerm: dec.term,
+			Index:   dec.index,
+		}
+
+		// decode entries
+		if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
+			return m, err
+		}
+		l := binary.BigEndian.Uint64(dec.uint64buf)
+		m.Entries = make([]raftpb.Entry, int(l))
+		for i := 0; i < int(l); i++ {
+			if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
+				return m, err
+			}
+			size := binary.BigEndian.Uint64(dec.uint64buf)
+			var buf []byte
+			if size < msgAppV2BufSize {
+				buf = dec.buf[:size]
+				if _, err := io.ReadFull(dec.r, buf); err != nil {
+					return m, err
+				}
+			} else {
+				buf = make([]byte, int(size))
+				if _, err := io.ReadFull(dec.r, buf); err != nil {
+					return m, err
+				}
+			}
+			dec.index++
+			// 1 alloc
+			pbutil.MustUnmarshal(&m.Entries[i], buf)
+		}
+		// decode commit index
+		if _, err := io.ReadFull(dec.r, dec.uint64buf); err != nil {
+			return m, err
+		}
+		m.Commit = binary.BigEndian.Uint64(dec.uint64buf)
+	case msgTypeApp:
+		var size uint64
+		if err := binary.Read(dec.r, binary.BigEndian, &size); err != nil {
+			return m, err
+		}
+		buf := make([]byte, int(size))
+		if _, err := io.ReadFull(dec.r, buf); err != nil {
+			return m, err
+		}
+		pbutil.MustUnmarshal(&m, buf)
+
+		dec.term = m.Term
+		dec.index = m.Index
+		if l := len(m.Entries); l > 0 {
+			dec.index = m.Entries[l-1].Index
+		}
+	default:
+		return m, fmt.Errorf("failed to parse type %d in msgappv2 stream", typ)
+	}
+	return m, nil
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer.go
new file mode 100644
index 0000000..8130c4a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer.go
@@ -0,0 +1,374 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"go.uber.org/zap"
+	"golang.org/x/time/rate"
+)
+
+const (
+	// ConnReadTimeout and ConnWriteTimeout are the i/o timeout set on each connection rafthttp pkg creates.
+	// A 5 seconds timeout is good enough for recycling bad connections. Or we have to wait for
+	// tcp keepalive failing to detect a bad connection, which is at minutes level.
+	// For long term streaming connections, rafthttp pkg sends application level linkHeartbeatMessage
+	// to keep the connection alive.
+	// For short term pipeline connections, the connection MUST be killed to avoid it being
+	// put back to http pkg connection pool.
+	ConnReadTimeout  = 5 * time.Second
+	ConnWriteTimeout = 5 * time.Second
+
+	recvBufSize = 4096
+	// maxPendingProposals holds the proposals during one leader election process.
+	// Generally one leader election takes at most 1 sec. It should have
+	// 0-2 election conflicts, and each one takes 0.5 sec.
+	// We assume the number of concurrent proposers is smaller than 4096.
+	// One client blocks on its proposal for at least 1 sec, so 4096 is enough
+	// to hold all proposals.
+	maxPendingProposals = 4096
+
+	streamAppV2 = "streamMsgAppV2"
+	streamMsg   = "streamMsg"
+	pipelineMsg = "pipeline"
+	sendSnap    = "sendMsgSnap"
+)
+
+type Peer interface {
+	// send sends the message to the remote peer. The function is non-blocking
+	// and has no promise that the message will be received by the remote.
+	// When it fails to send message out, it will report the status to underlying
+	// raft.
+	send(m raftpb.Message)
+
+	// sendSnap sends the merged snapshot message to the remote peer. Its behavior
+	// is similar to send.
+	sendSnap(m snap.Message)
+
+	// update updates the urls of remote peer.
+	update(urls types.URLs)
+
+	// attachOutgoingConn attaches the outgoing connection to the peer for
+	// stream usage. After the call, the ownership of the outgoing
+	// connection hands over to the peer. The peer will close the connection
+	// when it is no longer used.
+	attachOutgoingConn(conn *outgoingConn)
+	// activeSince returns the time that the connection with the
+	// peer becomes active.
+	activeSince() time.Time
+	// stop performs any necessary finalization and terminates the peer
+	// elegantly.
+	stop()
+}
+
+// peer is the representative of a remote raft node. Local raft node sends
+// messages to the remote through peer.
+// Each peer has two underlying mechanisms to send out a message: stream and
+// pipeline.
+// A stream is a receiver initialized long-polling connection, which
+// is always open to transfer messages. Besides general stream, peer also has
+// a optimized stream for sending msgApp since msgApp accounts for large part
+// of all messages. Only raft leader uses the optimized stream to send msgApp
+// to the remote follower node.
+// A pipeline is a series of http clients that send http requests to the remote.
+// It is only used when the stream has not been established.
+type peer struct {
+	lg *zap.Logger
+
+	localID types.ID
+	// id of the remote raft peer node
+	id types.ID
+
+	r Raft
+
+	status *peerStatus
+
+	picker *urlPicker
+
+	msgAppV2Writer *streamWriter
+	writer         *streamWriter
+	pipeline       *pipeline
+	snapSender     *snapshotSender // snapshot sender to send v3 snapshot messages
+	msgAppV2Reader *streamReader
+	msgAppReader   *streamReader
+
+	recvc chan raftpb.Message
+	propc chan raftpb.Message
+
+	mu     sync.Mutex
+	paused bool
+
+	cancel context.CancelFunc // cancel pending works in go routine created by peer.
+	stopc  chan struct{}
+}
+
+func startPeer(t *Transport, urls types.URLs, peerID types.ID, fs *stats.FollowerStats) *peer {
+	if t.Logger != nil {
+		t.Logger.Info("starting remote peer", zap.String("remote-peer-id", peerID.String()))
+	} else {
+		plog.Infof("starting peer %s...", peerID)
+	}
+	defer func() {
+		if t.Logger != nil {
+			t.Logger.Info("started remote peer", zap.String("remote-peer-id", peerID.String()))
+		} else {
+			plog.Infof("started peer %s", peerID)
+		}
+	}()
+
+	status := newPeerStatus(t.Logger, t.ID, peerID)
+	picker := newURLPicker(urls)
+	errorc := t.ErrorC
+	r := t.Raft
+	pipeline := &pipeline{
+		peerID:        peerID,
+		tr:            t,
+		picker:        picker,
+		status:        status,
+		followerStats: fs,
+		raft:          r,
+		errorc:        errorc,
+	}
+	pipeline.start()
+
+	p := &peer{
+		lg:             t.Logger,
+		localID:        t.ID,
+		id:             peerID,
+		r:              r,
+		status:         status,
+		picker:         picker,
+		msgAppV2Writer: startStreamWriter(t.Logger, t.ID, peerID, status, fs, r),
+		writer:         startStreamWriter(t.Logger, t.ID, peerID, status, fs, r),
+		pipeline:       pipeline,
+		snapSender:     newSnapshotSender(t, picker, peerID, status),
+		recvc:          make(chan raftpb.Message, recvBufSize),
+		propc:          make(chan raftpb.Message, maxPendingProposals),
+		stopc:          make(chan struct{}),
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	p.cancel = cancel
+	go func() {
+		for {
+			select {
+			case mm := <-p.recvc:
+				if err := r.Process(ctx, mm); err != nil {
+					if t.Logger != nil {
+						t.Logger.Warn("failed to process Raft message", zap.Error(err))
+					} else {
+						plog.Warningf("failed to process raft message (%v)", err)
+					}
+				}
+			case <-p.stopc:
+				return
+			}
+		}
+	}()
+
+	// r.Process might block for processing proposal when there is no leader.
+	// Thus propc must be put into a separate routine with recvc to avoid blocking
+	// processing other raft messages.
+	go func() {
+		for {
+			select {
+			case mm := <-p.propc:
+				if err := r.Process(ctx, mm); err != nil {
+					plog.Warningf("failed to process raft message (%v)", err)
+				}
+			case <-p.stopc:
+				return
+			}
+		}
+	}()
+
+	p.msgAppV2Reader = &streamReader{
+		lg:     t.Logger,
+		peerID: peerID,
+		typ:    streamTypeMsgAppV2,
+		tr:     t,
+		picker: picker,
+		status: status,
+		recvc:  p.recvc,
+		propc:  p.propc,
+		rl:     rate.NewLimiter(t.DialRetryFrequency, 1),
+	}
+	p.msgAppReader = &streamReader{
+		lg:     t.Logger,
+		peerID: peerID,
+		typ:    streamTypeMessage,
+		tr:     t,
+		picker: picker,
+		status: status,
+		recvc:  p.recvc,
+		propc:  p.propc,
+		rl:     rate.NewLimiter(t.DialRetryFrequency, 1),
+	}
+
+	p.msgAppV2Reader.start()
+	p.msgAppReader.start()
+
+	return p
+}
+
+func (p *peer) send(m raftpb.Message) {
+	p.mu.Lock()
+	paused := p.paused
+	p.mu.Unlock()
+
+	if paused {
+		return
+	}
+
+	writec, name := p.pick(m)
+	select {
+	case writec <- m:
+	default:
+		p.r.ReportUnreachable(m.To)
+		if isMsgSnap(m) {
+			p.r.ReportSnapshot(m.To, raft.SnapshotFailure)
+		}
+		if p.status.isActive() {
+			if p.lg != nil {
+				p.lg.Warn(
+					"dropped internal Raft message since sending buffer is full (overloaded network)",
+					zap.String("message-type", m.Type.String()),
+					zap.String("local-member-id", p.localID.String()),
+					zap.String("from", types.ID(m.From).String()),
+					zap.String("remote-peer-id", p.id.String()),
+					zap.Bool("remote-peer-active", p.status.isActive()),
+				)
+			} else {
+				plog.MergeWarningf("dropped internal raft message to %s since %s's sending buffer is full (bad/overloaded network)", p.id, name)
+			}
+		} else {
+			if p.lg != nil {
+				p.lg.Warn(
+					"dropped internal Raft message since sending buffer is full (overloaded network)",
+					zap.String("message-type", m.Type.String()),
+					zap.String("local-member-id", p.localID.String()),
+					zap.String("from", types.ID(m.From).String()),
+					zap.String("remote-peer-id", p.id.String()),
+					zap.Bool("remote-peer-active", p.status.isActive()),
+				)
+			} else {
+				plog.Debugf("dropped %s to %s since %s's sending buffer is full", m.Type, p.id, name)
+			}
+		}
+		sentFailures.WithLabelValues(types.ID(m.To).String()).Inc()
+	}
+}
+
+func (p *peer) sendSnap(m snap.Message) {
+	go p.snapSender.send(m)
+}
+
+func (p *peer) update(urls types.URLs) {
+	p.picker.update(urls)
+}
+
+func (p *peer) attachOutgoingConn(conn *outgoingConn) {
+	var ok bool
+	switch conn.t {
+	case streamTypeMsgAppV2:
+		ok = p.msgAppV2Writer.attach(conn)
+	case streamTypeMessage:
+		ok = p.writer.attach(conn)
+	default:
+		if p.lg != nil {
+			p.lg.Panic("unknown stream type", zap.String("type", conn.t.String()))
+		} else {
+			plog.Panicf("unhandled stream type %s", conn.t)
+		}
+	}
+	if !ok {
+		conn.Close()
+	}
+}
+
+func (p *peer) activeSince() time.Time { return p.status.activeSince() }
+
+// Pause pauses the peer. The peer will simply drops all incoming
+// messages without returning an error.
+func (p *peer) Pause() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.paused = true
+	p.msgAppReader.pause()
+	p.msgAppV2Reader.pause()
+}
+
+// Resume resumes a paused peer.
+func (p *peer) Resume() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.paused = false
+	p.msgAppReader.resume()
+	p.msgAppV2Reader.resume()
+}
+
+func (p *peer) stop() {
+	if p.lg != nil {
+		p.lg.Info("stopping remote peer", zap.String("remote-peer-id", p.id.String()))
+	} else {
+		plog.Infof("stopping peer %s...", p.id)
+	}
+
+	defer func() {
+		if p.lg != nil {
+			p.lg.Info("stopped remote peer", zap.String("remote-peer-id", p.id.String()))
+		} else {
+			plog.Infof("stopped peer %s", p.id)
+		}
+	}()
+
+	close(p.stopc)
+	p.cancel()
+	p.msgAppV2Writer.stop()
+	p.writer.stop()
+	p.pipeline.stop()
+	p.snapSender.stop()
+	p.msgAppV2Reader.stop()
+	p.msgAppReader.stop()
+}
+
+// pick picks a chan for sending the given message. The picked chan and the picked chan
+// string name are returned.
+func (p *peer) pick(m raftpb.Message) (writec chan<- raftpb.Message, picked string) {
+	var ok bool
+	// Considering MsgSnap may have a big size, e.g., 1G, and will block
+	// stream for a long time, only use one of the N pipelines to send MsgSnap.
+	if isMsgSnap(m) {
+		return p.pipeline.msgc, pipelineMsg
+	} else if writec, ok = p.msgAppV2Writer.writec(); ok && isMsgApp(m) {
+		return writec, streamAppV2
+	} else if writec, ok = p.writer.writec(); ok {
+		return writec, streamMsg
+	}
+	return p.pipeline.msgc, pipelineMsg
+}
+
+func isMsgApp(m raftpb.Message) bool { return m.Type == raftpb.MsgApp }
+
+func isMsgSnap(m raftpb.Message) bool { return m.Type == raftpb.MsgSnap }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer_status.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer_status.go
new file mode 100644
index 0000000..66149ff
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/peer_status.go
@@ -0,0 +1,96 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/pkg/types"
+
+	"go.uber.org/zap"
+)
+
+type failureType struct {
+	source string
+	action string
+}
+
+type peerStatus struct {
+	lg     *zap.Logger
+	local  types.ID
+	id     types.ID
+	mu     sync.Mutex // protect variables below
+	active bool
+	since  time.Time
+}
+
+func newPeerStatus(lg *zap.Logger, local, id types.ID) *peerStatus {
+	return &peerStatus{lg: lg, local: local, id: id}
+}
+
+func (s *peerStatus) activate() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.active {
+		if s.lg != nil {
+			s.lg.Info("peer became active", zap.String("peer-id", s.id.String()))
+		} else {
+			plog.Infof("peer %s became active", s.id)
+		}
+		s.active = true
+		s.since = time.Now()
+
+		activePeers.WithLabelValues(s.local.String(), s.id.String()).Inc()
+	}
+}
+
+func (s *peerStatus) deactivate(failure failureType, reason string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	msg := fmt.Sprintf("failed to %s %s on %s (%s)", failure.action, s.id, failure.source, reason)
+	if s.active {
+		if s.lg != nil {
+			s.lg.Warn("peer became inactive (message send to peer failed)", zap.String("peer-id", s.id.String()), zap.Error(errors.New(msg)))
+		} else {
+			plog.Errorf(msg)
+			plog.Infof("peer %s became inactive (message send to peer failed)", s.id)
+		}
+		s.active = false
+		s.since = time.Time{}
+
+		activePeers.WithLabelValues(s.local.String(), s.id.String()).Dec()
+		disconnectedPeers.WithLabelValues(s.local.String(), s.id.String()).Inc()
+		return
+	}
+
+	if s.lg != nil {
+		s.lg.Debug("peer deactivated again", zap.String("peer-id", s.id.String()), zap.Error(errors.New(msg)))
+	}
+}
+
+func (s *peerStatus) isActive() bool {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.active
+}
+
+func (s *peerStatus) activeSince() time.Time {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.since
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/pipeline.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/pipeline.go
new file mode 100644
index 0000000..70f9257
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/pipeline.go
@@ -0,0 +1,180 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io/ioutil"
+	"sync"
+	"time"
+
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"go.uber.org/zap"
+)
+
+const (
+	connPerPipeline = 4
+	// pipelineBufSize is the size of pipeline buffer, which helps hold the
+	// temporary network latency.
+	// The size ensures that pipeline does not drop messages when the network
+	// is out of work for less than 1 second in good path.
+	pipelineBufSize = 64
+)
+
+var errStopped = errors.New("stopped")
+
+type pipeline struct {
+	peerID types.ID
+
+	tr     *Transport
+	picker *urlPicker
+	status *peerStatus
+	raft   Raft
+	errorc chan error
+	// deprecate when we depercate v2 API
+	followerStats *stats.FollowerStats
+
+	msgc chan raftpb.Message
+	// wait for the handling routines
+	wg    sync.WaitGroup
+	stopc chan struct{}
+}
+
+func (p *pipeline) start() {
+	p.stopc = make(chan struct{})
+	p.msgc = make(chan raftpb.Message, pipelineBufSize)
+	p.wg.Add(connPerPipeline)
+	for i := 0; i < connPerPipeline; i++ {
+		go p.handle()
+	}
+
+	if p.tr != nil && p.tr.Logger != nil {
+		p.tr.Logger.Info(
+			"started HTTP pipelining with remote peer",
+			zap.String("local-member-id", p.tr.ID.String()),
+			zap.String("remote-peer-id", p.peerID.String()),
+		)
+	} else {
+		plog.Infof("started HTTP pipelining with peer %s", p.peerID)
+	}
+}
+
+func (p *pipeline) stop() {
+	close(p.stopc)
+	p.wg.Wait()
+
+	if p.tr != nil && p.tr.Logger != nil {
+		p.tr.Logger.Info(
+			"stopped HTTP pipelining with remote peer",
+			zap.String("local-member-id", p.tr.ID.String()),
+			zap.String("remote-peer-id", p.peerID.String()),
+		)
+	} else {
+		plog.Infof("stopped HTTP pipelining with peer %s", p.peerID)
+	}
+}
+
+func (p *pipeline) handle() {
+	defer p.wg.Done()
+
+	for {
+		select {
+		case m := <-p.msgc:
+			start := time.Now()
+			err := p.post(pbutil.MustMarshal(&m))
+			end := time.Now()
+
+			if err != nil {
+				p.status.deactivate(failureType{source: pipelineMsg, action: "write"}, err.Error())
+
+				if m.Type == raftpb.MsgApp && p.followerStats != nil {
+					p.followerStats.Fail()
+				}
+				p.raft.ReportUnreachable(m.To)
+				if isMsgSnap(m) {
+					p.raft.ReportSnapshot(m.To, raft.SnapshotFailure)
+				}
+				sentFailures.WithLabelValues(types.ID(m.To).String()).Inc()
+				continue
+			}
+
+			p.status.activate()
+			if m.Type == raftpb.MsgApp && p.followerStats != nil {
+				p.followerStats.Succ(end.Sub(start))
+			}
+			if isMsgSnap(m) {
+				p.raft.ReportSnapshot(m.To, raft.SnapshotFinish)
+			}
+			sentBytes.WithLabelValues(types.ID(m.To).String()).Add(float64(m.Size()))
+		case <-p.stopc:
+			return
+		}
+	}
+}
+
+// post POSTs a data payload to a url. Returns nil if the POST succeeds,
+// error on any failure.
+func (p *pipeline) post(data []byte) (err error) {
+	u := p.picker.pick()
+	req := createPostRequest(u, RaftPrefix, bytes.NewBuffer(data), "application/protobuf", p.tr.URLs, p.tr.ID, p.tr.ClusterID)
+
+	done := make(chan struct{}, 1)
+	ctx, cancel := context.WithCancel(context.Background())
+	req = req.WithContext(ctx)
+	go func() {
+		select {
+		case <-done:
+		case <-p.stopc:
+			waitSchedule()
+			cancel()
+		}
+	}()
+
+	resp, err := p.tr.pipelineRt.RoundTrip(req)
+	done <- struct{}{}
+	if err != nil {
+		p.picker.unreachable(u)
+		return err
+	}
+	defer resp.Body.Close()
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		p.picker.unreachable(u)
+		return err
+	}
+
+	err = checkPostResponse(resp, b, req, p.peerID)
+	if err != nil {
+		p.picker.unreachable(u)
+		// errMemberRemoved is a critical error since a removed member should
+		// always be stopped. So we use reportCriticalError to report it to errorc.
+		if err == errMemberRemoved {
+			reportCriticalError(err, p.errorc)
+		}
+		return err
+	}
+
+	return nil
+}
+
+// waitSchedule waits other goroutines to be scheduled for a while
+func waitSchedule() { time.Sleep(time.Millisecond) }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/probing_status.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/probing_status.go
new file mode 100644
index 0000000..474d9a0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/probing_status.go
@@ -0,0 +1,104 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/xiang90/probing"
+	"go.uber.org/zap"
+)
+
+const (
+	// RoundTripperNameRaftMessage is the name of round-tripper that sends
+	// all other Raft messages, other than "snap.Message".
+	RoundTripperNameRaftMessage = "ROUND_TRIPPER_RAFT_MESSAGE"
+	// RoundTripperNameSnapshot is the name of round-tripper that sends merged snapshot message.
+	RoundTripperNameSnapshot = "ROUND_TRIPPER_SNAPSHOT"
+)
+
+var (
+	// proberInterval must be shorter than read timeout.
+	// Or the connection will time-out.
+	proberInterval           = ConnReadTimeout - time.Second
+	statusMonitoringInterval = 30 * time.Second
+	statusErrorInterval      = 5 * time.Second
+)
+
+func addPeerToProber(lg *zap.Logger, p probing.Prober, id string, us []string, roundTripperName string, rttSecProm *prometheus.HistogramVec) {
+	hus := make([]string, len(us))
+	for i := range us {
+		hus[i] = us[i] + ProbingPrefix
+	}
+
+	p.AddHTTP(id, proberInterval, hus)
+
+	s, err := p.Status(id)
+	if err != nil {
+		if lg != nil {
+			lg.Warn("failed to add peer into prober", zap.String("remote-peer-id", id))
+		} else {
+			plog.Errorf("failed to add peer %s into prober", id)
+		}
+		return
+	}
+
+	go monitorProbingStatus(lg, s, id, roundTripperName, rttSecProm)
+}
+
+func monitorProbingStatus(lg *zap.Logger, s probing.Status, id string, roundTripperName string, rttSecProm *prometheus.HistogramVec) {
+	// set the first interval short to log error early.
+	interval := statusErrorInterval
+	for {
+		select {
+		case <-time.After(interval):
+			if !s.Health() {
+				if lg != nil {
+					lg.Warn(
+						"prober detected unhealthy status",
+						zap.String("round-tripper-name", roundTripperName),
+						zap.String("remote-peer-id", id),
+						zap.Duration("rtt", s.SRTT()),
+						zap.Error(s.Err()),
+					)
+				} else {
+					plog.Warningf("health check for peer %s could not connect: %v", id, s.Err())
+				}
+				interval = statusErrorInterval
+			} else {
+				interval = statusMonitoringInterval
+			}
+			if s.ClockDiff() > time.Second {
+				if lg != nil {
+					lg.Warn(
+						"prober found high clock drift",
+						zap.String("round-tripper-name", roundTripperName),
+						zap.String("remote-peer-id", id),
+						zap.Duration("clock-drift", s.ClockDiff()),
+						zap.Duration("rtt", s.SRTT()),
+						zap.Error(s.Err()),
+					)
+				} else {
+					plog.Warningf("the clock difference against peer %s is too high [%v > %v]", id, s.ClockDiff(), time.Second)
+				}
+			}
+			rttSecProm.WithLabelValues(id).Observe(s.SRTT().Seconds())
+
+		case <-s.StopNotify():
+			return
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/remote.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/remote.go
new file mode 100644
index 0000000..1ef2493
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/remote.go
@@ -0,0 +1,99 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"go.uber.org/zap"
+)
+
+type remote struct {
+	lg       *zap.Logger
+	localID  types.ID
+	id       types.ID
+	status   *peerStatus
+	pipeline *pipeline
+}
+
+func startRemote(tr *Transport, urls types.URLs, id types.ID) *remote {
+	picker := newURLPicker(urls)
+	status := newPeerStatus(tr.Logger, tr.ID, id)
+	pipeline := &pipeline{
+		peerID: id,
+		tr:     tr,
+		picker: picker,
+		status: status,
+		raft:   tr.Raft,
+		errorc: tr.ErrorC,
+	}
+	pipeline.start()
+
+	return &remote{
+		lg:       tr.Logger,
+		localID:  tr.ID,
+		id:       id,
+		status:   status,
+		pipeline: pipeline,
+	}
+}
+
+func (g *remote) send(m raftpb.Message) {
+	select {
+	case g.pipeline.msgc <- m:
+	default:
+		if g.status.isActive() {
+			if g.lg != nil {
+				g.lg.Warn(
+					"dropped internal Raft message since sending buffer is full (overloaded network)",
+					zap.String("message-type", m.Type.String()),
+					zap.String("local-member-id", g.localID.String()),
+					zap.String("from", types.ID(m.From).String()),
+					zap.String("remote-peer-id", g.id.String()),
+					zap.Bool("remote-peer-active", g.status.isActive()),
+				)
+			} else {
+				plog.MergeWarningf("dropped internal raft message to %s since sending buffer is full (bad/overloaded network)", g.id)
+			}
+		} else {
+			if g.lg != nil {
+				g.lg.Warn(
+					"dropped Raft message since sending buffer is full (overloaded network)",
+					zap.String("message-type", m.Type.String()),
+					zap.String("local-member-id", g.localID.String()),
+					zap.String("from", types.ID(m.From).String()),
+					zap.String("remote-peer-id", g.id.String()),
+					zap.Bool("remote-peer-active", g.status.isActive()),
+				)
+			} else {
+				plog.Debugf("dropped %s to %s since sending buffer is full", m.Type, g.id)
+			}
+		}
+		sentFailures.WithLabelValues(types.ID(m.To).String()).Inc()
+	}
+}
+
+func (g *remote) stop() {
+	g.pipeline.stop()
+}
+
+func (g *remote) Pause() {
+	g.stop()
+}
+
+func (g *remote) Resume() {
+	g.pipeline.start()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/snapshot_sender.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/snapshot_sender.go
new file mode 100644
index 0000000..62efb0c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/snapshot_sender.go
@@ -0,0 +1,207 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	"go.etcd.io/etcd/pkg/httputil"
+	pioutil "go.etcd.io/etcd/pkg/ioutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+
+	"github.com/dustin/go-humanize"
+	"go.uber.org/zap"
+)
+
+var (
+	// timeout for reading snapshot response body
+	snapResponseReadTimeout = 5 * time.Second
+)
+
+type snapshotSender struct {
+	from, to types.ID
+	cid      types.ID
+
+	tr     *Transport
+	picker *urlPicker
+	status *peerStatus
+	r      Raft
+	errorc chan error
+
+	stopc chan struct{}
+}
+
+func newSnapshotSender(tr *Transport, picker *urlPicker, to types.ID, status *peerStatus) *snapshotSender {
+	return &snapshotSender{
+		from:   tr.ID,
+		to:     to,
+		cid:    tr.ClusterID,
+		tr:     tr,
+		picker: picker,
+		status: status,
+		r:      tr.Raft,
+		errorc: tr.ErrorC,
+		stopc:  make(chan struct{}),
+	}
+}
+
+func (s *snapshotSender) stop() { close(s.stopc) }
+
+func (s *snapshotSender) send(merged snap.Message) {
+	start := time.Now()
+
+	m := merged.Message
+	to := types.ID(m.To).String()
+
+	body := createSnapBody(s.tr.Logger, merged)
+	defer body.Close()
+
+	u := s.picker.pick()
+	req := createPostRequest(u, RaftSnapshotPrefix, body, "application/octet-stream", s.tr.URLs, s.from, s.cid)
+
+	if s.tr.Logger != nil {
+		s.tr.Logger.Info(
+			"sending database snapshot",
+			zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index),
+			zap.String("remote-peer-id", to),
+			zap.Int64("bytes", merged.TotalSize),
+			zap.String("size", humanize.Bytes(uint64(merged.TotalSize))),
+		)
+	} else {
+		plog.Infof("start to send database snapshot [index: %d, to %s]...", m.Snapshot.Metadata.Index, types.ID(m.To))
+	}
+
+	snapshotSendInflights.WithLabelValues(to).Inc()
+	defer func() {
+		snapshotSendInflights.WithLabelValues(to).Dec()
+	}()
+
+	err := s.post(req)
+	defer merged.CloseWithError(err)
+	if err != nil {
+		if s.tr.Logger != nil {
+			s.tr.Logger.Warn(
+				"failed to send database snapshot",
+				zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index),
+				zap.String("remote-peer-id", to),
+				zap.Int64("bytes", merged.TotalSize),
+				zap.String("size", humanize.Bytes(uint64(merged.TotalSize))),
+				zap.Error(err),
+			)
+		} else {
+			plog.Warningf("database snapshot [index: %d, to: %s] failed to be sent out (%v)", m.Snapshot.Metadata.Index, types.ID(m.To), err)
+		}
+
+		// errMemberRemoved is a critical error since a removed member should
+		// always be stopped. So we use reportCriticalError to report it to errorc.
+		if err == errMemberRemoved {
+			reportCriticalError(err, s.errorc)
+		}
+
+		s.picker.unreachable(u)
+		s.status.deactivate(failureType{source: sendSnap, action: "post"}, err.Error())
+		s.r.ReportUnreachable(m.To)
+		// report SnapshotFailure to raft state machine. After raft state
+		// machine knows about it, it would pause a while and retry sending
+		// new snapshot message.
+		s.r.ReportSnapshot(m.To, raft.SnapshotFailure)
+		sentFailures.WithLabelValues(to).Inc()
+		snapshotSendFailures.WithLabelValues(to).Inc()
+		return
+	}
+	s.status.activate()
+	s.r.ReportSnapshot(m.To, raft.SnapshotFinish)
+
+	if s.tr.Logger != nil {
+		s.tr.Logger.Info(
+			"sent database snapshot",
+			zap.Uint64("snapshot-index", m.Snapshot.Metadata.Index),
+			zap.String("remote-peer-id", to),
+			zap.Int64("bytes", merged.TotalSize),
+			zap.String("size", humanize.Bytes(uint64(merged.TotalSize))),
+		)
+	} else {
+		plog.Infof("database snapshot [index: %d, to: %s] sent out successfully", m.Snapshot.Metadata.Index, types.ID(m.To))
+	}
+
+	sentBytes.WithLabelValues(to).Add(float64(merged.TotalSize))
+	snapshotSend.WithLabelValues(to).Inc()
+	snapshotSendSeconds.WithLabelValues(to).Observe(time.Since(start).Seconds())
+}
+
+// post posts the given request.
+// It returns nil when request is sent out and processed successfully.
+func (s *snapshotSender) post(req *http.Request) (err error) {
+	ctx, cancel := context.WithCancel(context.Background())
+	req = req.WithContext(ctx)
+	defer cancel()
+
+	type responseAndError struct {
+		resp *http.Response
+		body []byte
+		err  error
+	}
+	result := make(chan responseAndError, 1)
+
+	go func() {
+		resp, err := s.tr.pipelineRt.RoundTrip(req)
+		if err != nil {
+			result <- responseAndError{resp, nil, err}
+			return
+		}
+
+		// close the response body when timeouts.
+		// prevents from reading the body forever when the other side dies right after
+		// successfully receives the request body.
+		time.AfterFunc(snapResponseReadTimeout, func() { httputil.GracefulClose(resp) })
+		body, err := ioutil.ReadAll(resp.Body)
+		result <- responseAndError{resp, body, err}
+	}()
+
+	select {
+	case <-s.stopc:
+		return errStopped
+	case r := <-result:
+		if r.err != nil {
+			return r.err
+		}
+		return checkPostResponse(r.resp, r.body, req, s.to)
+	}
+}
+
+func createSnapBody(lg *zap.Logger, merged snap.Message) io.ReadCloser {
+	buf := new(bytes.Buffer)
+	enc := &messageEncoder{w: buf}
+	// encode raft message
+	if err := enc.encode(&merged.Message); err != nil {
+		if lg != nil {
+			lg.Panic("failed to encode message", zap.Error(err))
+		} else {
+			plog.Panicf("encode message error (%v)", err)
+		}
+	}
+
+	return &pioutil.ReaderAndCloser{
+		Reader: io.MultiReader(buf, merged.ReadCloser),
+		Closer: merged.ReadCloser,
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/stream.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/stream.go
new file mode 100644
index 0000000..dcb2223
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/stream.go
@@ -0,0 +1,746 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"path"
+	"strings"
+	"sync"
+	"time"
+
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/pkg/httputil"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/go-semver/semver"
+	"go.uber.org/zap"
+	"golang.org/x/time/rate"
+)
+
+const (
+	streamTypeMessage  streamType = "message"
+	streamTypeMsgAppV2 streamType = "msgappv2"
+
+	streamBufSize = 4096
+)
+
+var (
+	errUnsupportedStreamType = fmt.Errorf("unsupported stream type")
+
+	// the key is in string format "major.minor.patch"
+	supportedStream = map[string][]streamType{
+		"2.0.0": {},
+		"2.1.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"2.2.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"2.3.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"3.0.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"3.1.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"3.2.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"3.3.0": {streamTypeMsgAppV2, streamTypeMessage},
+	}
+)
+
+type streamType string
+
+func (t streamType) endpoint() string {
+	switch t {
+	case streamTypeMsgAppV2:
+		return path.Join(RaftStreamPrefix, "msgapp")
+	case streamTypeMessage:
+		return path.Join(RaftStreamPrefix, "message")
+	default:
+		plog.Panicf("unhandled stream type %v", t)
+		return ""
+	}
+}
+
+func (t streamType) String() string {
+	switch t {
+	case streamTypeMsgAppV2:
+		return "stream MsgApp v2"
+	case streamTypeMessage:
+		return "stream Message"
+	default:
+		return "unknown stream"
+	}
+}
+
+var (
+	// linkHeartbeatMessage is a special message used as heartbeat message in
+	// link layer. It never conflicts with messages from raft because raft
+	// doesn't send out messages without From and To fields.
+	linkHeartbeatMessage = raftpb.Message{Type: raftpb.MsgHeartbeat}
+)
+
+func isLinkHeartbeatMessage(m *raftpb.Message) bool {
+	return m.Type == raftpb.MsgHeartbeat && m.From == 0 && m.To == 0
+}
+
+type outgoingConn struct {
+	t streamType
+	io.Writer
+	http.Flusher
+	io.Closer
+
+	localID types.ID
+	peerID  types.ID
+}
+
+// streamWriter writes messages to the attached outgoingConn.
+type streamWriter struct {
+	lg *zap.Logger
+
+	localID types.ID
+	peerID  types.ID
+
+	status *peerStatus
+	fs     *stats.FollowerStats
+	r      Raft
+
+	mu      sync.Mutex // guard field working and closer
+	closer  io.Closer
+	working bool
+
+	msgc  chan raftpb.Message
+	connc chan *outgoingConn
+	stopc chan struct{}
+	done  chan struct{}
+}
+
+// startStreamWriter creates a streamWrite and starts a long running go-routine that accepts
+// messages and writes to the attached outgoing connection.
+func startStreamWriter(lg *zap.Logger, local, id types.ID, status *peerStatus, fs *stats.FollowerStats, r Raft) *streamWriter {
+	w := &streamWriter{
+		lg: lg,
+
+		localID: local,
+		peerID:  id,
+
+		status: status,
+		fs:     fs,
+		r:      r,
+		msgc:   make(chan raftpb.Message, streamBufSize),
+		connc:  make(chan *outgoingConn),
+		stopc:  make(chan struct{}),
+		done:   make(chan struct{}),
+	}
+	go w.run()
+	return w
+}
+
+func (cw *streamWriter) run() {
+	var (
+		msgc       chan raftpb.Message
+		heartbeatc <-chan time.Time
+		t          streamType
+		enc        encoder
+		flusher    http.Flusher
+		batched    int
+	)
+	tickc := time.NewTicker(ConnReadTimeout / 3)
+	defer tickc.Stop()
+	unflushed := 0
+
+	if cw.lg != nil {
+		cw.lg.Info(
+			"started stream writer with remote peer",
+			zap.String("local-member-id", cw.localID.String()),
+			zap.String("remote-peer-id", cw.peerID.String()),
+		)
+	} else {
+		plog.Infof("started streaming with peer %s (writer)", cw.peerID)
+	}
+
+	for {
+		select {
+		case <-heartbeatc:
+			err := enc.encode(&linkHeartbeatMessage)
+			unflushed += linkHeartbeatMessage.Size()
+			if err == nil {
+				flusher.Flush()
+				batched = 0
+				sentBytes.WithLabelValues(cw.peerID.String()).Add(float64(unflushed))
+				unflushed = 0
+				continue
+			}
+
+			cw.status.deactivate(failureType{source: t.String(), action: "heartbeat"}, err.Error())
+
+			sentFailures.WithLabelValues(cw.peerID.String()).Inc()
+			cw.close()
+			if cw.lg != nil {
+				cw.lg.Warn(
+					"lost TCP streaming connection with remote peer",
+					zap.String("stream-writer-type", t.String()),
+					zap.String("local-member-id", cw.localID.String()),
+					zap.String("remote-peer-id", cw.peerID.String()),
+				)
+			} else {
+				plog.Warningf("lost the TCP streaming connection with peer %s (%s writer)", cw.peerID, t)
+			}
+			heartbeatc, msgc = nil, nil
+
+		case m := <-msgc:
+			err := enc.encode(&m)
+			if err == nil {
+				unflushed += m.Size()
+
+				if len(msgc) == 0 || batched > streamBufSize/2 {
+					flusher.Flush()
+					sentBytes.WithLabelValues(cw.peerID.String()).Add(float64(unflushed))
+					unflushed = 0
+					batched = 0
+				} else {
+					batched++
+				}
+
+				continue
+			}
+
+			cw.status.deactivate(failureType{source: t.String(), action: "write"}, err.Error())
+			cw.close()
+			if cw.lg != nil {
+				cw.lg.Warn(
+					"lost TCP streaming connection with remote peer",
+					zap.String("stream-writer-type", t.String()),
+					zap.String("local-member-id", cw.localID.String()),
+					zap.String("remote-peer-id", cw.peerID.String()),
+				)
+			} else {
+				plog.Warningf("lost the TCP streaming connection with peer %s (%s writer)", cw.peerID, t)
+			}
+			heartbeatc, msgc = nil, nil
+			cw.r.ReportUnreachable(m.To)
+			sentFailures.WithLabelValues(cw.peerID.String()).Inc()
+
+		case conn := <-cw.connc:
+			cw.mu.Lock()
+			closed := cw.closeUnlocked()
+			t = conn.t
+			switch conn.t {
+			case streamTypeMsgAppV2:
+				enc = newMsgAppV2Encoder(conn.Writer, cw.fs)
+			case streamTypeMessage:
+				enc = &messageEncoder{w: conn.Writer}
+			default:
+				plog.Panicf("unhandled stream type %s", conn.t)
+			}
+			if cw.lg != nil {
+				cw.lg.Info(
+					"set message encoder",
+					zap.String("from", conn.localID.String()),
+					zap.String("to", conn.peerID.String()),
+					zap.String("stream-type", t.String()),
+				)
+			}
+			flusher = conn.Flusher
+			unflushed = 0
+			cw.status.activate()
+			cw.closer = conn.Closer
+			cw.working = true
+			cw.mu.Unlock()
+
+			if closed {
+				if cw.lg != nil {
+					cw.lg.Warn(
+						"closed TCP streaming connection with remote peer",
+						zap.String("stream-writer-type", t.String()),
+						zap.String("local-member-id", cw.localID.String()),
+						zap.String("remote-peer-id", cw.peerID.String()),
+					)
+				} else {
+					plog.Warningf("closed an existing TCP streaming connection with peer %s (%s writer)", cw.peerID, t)
+				}
+			}
+			if cw.lg != nil {
+				cw.lg.Warn(
+					"established TCP streaming connection with remote peer",
+					zap.String("stream-writer-type", t.String()),
+					zap.String("local-member-id", cw.localID.String()),
+					zap.String("remote-peer-id", cw.peerID.String()),
+				)
+			} else {
+				plog.Infof("established a TCP streaming connection with peer %s (%s writer)", cw.peerID, t)
+			}
+			heartbeatc, msgc = tickc.C, cw.msgc
+
+		case <-cw.stopc:
+			if cw.close() {
+				if cw.lg != nil {
+					cw.lg.Warn(
+						"closed TCP streaming connection with remote peer",
+						zap.String("stream-writer-type", t.String()),
+						zap.String("remote-peer-id", cw.peerID.String()),
+					)
+				} else {
+					plog.Infof("closed the TCP streaming connection with peer %s (%s writer)", cw.peerID, t)
+				}
+			}
+			if cw.lg != nil {
+				cw.lg.Warn(
+					"stopped TCP streaming connection with remote peer",
+					zap.String("stream-writer-type", t.String()),
+					zap.String("remote-peer-id", cw.peerID.String()),
+				)
+			} else {
+				plog.Infof("stopped streaming with peer %s (writer)", cw.peerID)
+			}
+			close(cw.done)
+			return
+		}
+	}
+}
+
+func (cw *streamWriter) writec() (chan<- raftpb.Message, bool) {
+	cw.mu.Lock()
+	defer cw.mu.Unlock()
+	return cw.msgc, cw.working
+}
+
+func (cw *streamWriter) close() bool {
+	cw.mu.Lock()
+	defer cw.mu.Unlock()
+	return cw.closeUnlocked()
+}
+
+func (cw *streamWriter) closeUnlocked() bool {
+	if !cw.working {
+		return false
+	}
+	if err := cw.closer.Close(); err != nil {
+		if cw.lg != nil {
+			cw.lg.Warn(
+				"failed to close connection with remote peer",
+				zap.String("remote-peer-id", cw.peerID.String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("peer %s (writer) connection close error: %v", cw.peerID, err)
+		}
+	}
+	if len(cw.msgc) > 0 {
+		cw.r.ReportUnreachable(uint64(cw.peerID))
+	}
+	cw.msgc = make(chan raftpb.Message, streamBufSize)
+	cw.working = false
+	return true
+}
+
+func (cw *streamWriter) attach(conn *outgoingConn) bool {
+	select {
+	case cw.connc <- conn:
+		return true
+	case <-cw.done:
+		return false
+	}
+}
+
+func (cw *streamWriter) stop() {
+	close(cw.stopc)
+	<-cw.done
+}
+
+// streamReader is a long-running go-routine that dials to the remote stream
+// endpoint and reads messages from the response body returned.
+type streamReader struct {
+	lg *zap.Logger
+
+	peerID types.ID
+	typ    streamType
+
+	tr     *Transport
+	picker *urlPicker
+	status *peerStatus
+	recvc  chan<- raftpb.Message
+	propc  chan<- raftpb.Message
+
+	rl *rate.Limiter // alters the frequency of dial retrial attempts
+
+	errorc chan<- error
+
+	mu     sync.Mutex
+	paused bool
+	closer io.Closer
+
+	ctx    context.Context
+	cancel context.CancelFunc
+	done   chan struct{}
+}
+
+func (cr *streamReader) start() {
+	cr.done = make(chan struct{})
+	if cr.errorc == nil {
+		cr.errorc = cr.tr.ErrorC
+	}
+	if cr.ctx == nil {
+		cr.ctx, cr.cancel = context.WithCancel(context.Background())
+	}
+	go cr.run()
+}
+
+func (cr *streamReader) run() {
+	t := cr.typ
+
+	if cr.lg != nil {
+		cr.lg.Info(
+			"started stream reader with remote peer",
+			zap.String("stream-reader-type", t.String()),
+			zap.String("local-member-id", cr.tr.ID.String()),
+			zap.String("remote-peer-id", cr.peerID.String()),
+		)
+	} else {
+		plog.Infof("started streaming with peer %s (%s reader)", cr.peerID, t)
+	}
+
+	for {
+		rc, err := cr.dial(t)
+		if err != nil {
+			if err != errUnsupportedStreamType {
+				cr.status.deactivate(failureType{source: t.String(), action: "dial"}, err.Error())
+			}
+		} else {
+			cr.status.activate()
+			if cr.lg != nil {
+				cr.lg.Info(
+					"established TCP streaming connection with remote peer",
+					zap.String("stream-reader-type", cr.typ.String()),
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+				)
+			} else {
+				plog.Infof("established a TCP streaming connection with peer %s (%s reader)", cr.peerID, cr.typ)
+			}
+			err = cr.decodeLoop(rc, t)
+			if cr.lg != nil {
+				cr.lg.Warn(
+					"lost TCP streaming connection with remote peer",
+					zap.String("stream-reader-type", cr.typ.String()),
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("lost the TCP streaming connection with peer %s (%s reader)", cr.peerID, cr.typ)
+			}
+			switch {
+			// all data is read out
+			case err == io.EOF:
+			// connection is closed by the remote
+			case transport.IsClosedConnError(err):
+			default:
+				cr.status.deactivate(failureType{source: t.String(), action: "read"}, err.Error())
+			}
+		}
+		// Wait for a while before new dial attempt
+		err = cr.rl.Wait(cr.ctx)
+		if cr.ctx.Err() != nil {
+			if cr.lg != nil {
+				cr.lg.Info(
+					"stopped stream reader with remote peer",
+					zap.String("stream-reader-type", t.String()),
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+				)
+			} else {
+				plog.Infof("stopped streaming with peer %s (%s reader)", cr.peerID, t)
+			}
+			close(cr.done)
+			return
+		}
+		if err != nil {
+			if cr.lg != nil {
+				cr.lg.Warn(
+					"rate limit on stream reader with remote peer",
+					zap.String("stream-reader-type", t.String()),
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("streaming with peer %s (%s reader) rate limiter error: %v", cr.peerID, t, err)
+			}
+		}
+	}
+}
+
+func (cr *streamReader) decodeLoop(rc io.ReadCloser, t streamType) error {
+	var dec decoder
+	cr.mu.Lock()
+	switch t {
+	case streamTypeMsgAppV2:
+		dec = newMsgAppV2Decoder(rc, cr.tr.ID, cr.peerID)
+	case streamTypeMessage:
+		dec = &messageDecoder{r: rc}
+	default:
+		if cr.lg != nil {
+			cr.lg.Panic("unknown stream type", zap.String("type", t.String()))
+		} else {
+			plog.Panicf("unhandled stream type %s", t)
+		}
+	}
+	select {
+	case <-cr.ctx.Done():
+		cr.mu.Unlock()
+		if err := rc.Close(); err != nil {
+			return err
+		}
+		return io.EOF
+	default:
+		cr.closer = rc
+	}
+	cr.mu.Unlock()
+
+	// gofail: labelRaftDropHeartbeat:
+	for {
+		m, err := dec.decode()
+		if err != nil {
+			cr.mu.Lock()
+			cr.close()
+			cr.mu.Unlock()
+			return err
+		}
+
+		// gofail-go: var raftDropHeartbeat struct{}
+		// continue labelRaftDropHeartbeat
+		receivedBytes.WithLabelValues(types.ID(m.From).String()).Add(float64(m.Size()))
+
+		cr.mu.Lock()
+		paused := cr.paused
+		cr.mu.Unlock()
+
+		if paused {
+			continue
+		}
+
+		if isLinkHeartbeatMessage(&m) {
+			// raft is not interested in link layer
+			// heartbeat message, so we should ignore
+			// it.
+			continue
+		}
+
+		recvc := cr.recvc
+		if m.Type == raftpb.MsgProp {
+			recvc = cr.propc
+		}
+
+		select {
+		case recvc <- m:
+		default:
+			if cr.status.isActive() {
+				if cr.lg != nil {
+					cr.lg.Warn(
+						"dropped internal Raft message since receiving buffer is full (overloaded network)",
+						zap.String("message-type", m.Type.String()),
+						zap.String("local-member-id", cr.tr.ID.String()),
+						zap.String("from", types.ID(m.From).String()),
+						zap.String("remote-peer-id", types.ID(m.To).String()),
+						zap.Bool("remote-peer-active", cr.status.isActive()),
+					)
+				} else {
+					plog.MergeWarningf("dropped internal raft message from %s since receiving buffer is full (overloaded network)", types.ID(m.From))
+				}
+			} else {
+				if cr.lg != nil {
+					cr.lg.Warn(
+						"dropped Raft message since receiving buffer is full (overloaded network)",
+						zap.String("message-type", m.Type.String()),
+						zap.String("local-member-id", cr.tr.ID.String()),
+						zap.String("from", types.ID(m.From).String()),
+						zap.String("remote-peer-id", types.ID(m.To).String()),
+						zap.Bool("remote-peer-active", cr.status.isActive()),
+					)
+				} else {
+					plog.Debugf("dropped %s from %s since receiving buffer is full", m.Type, types.ID(m.From))
+				}
+			}
+			recvFailures.WithLabelValues(types.ID(m.From).String()).Inc()
+		}
+	}
+}
+
+func (cr *streamReader) stop() {
+	cr.mu.Lock()
+	cr.cancel()
+	cr.close()
+	cr.mu.Unlock()
+	<-cr.done
+}
+
+func (cr *streamReader) dial(t streamType) (io.ReadCloser, error) {
+	u := cr.picker.pick()
+	uu := u
+	uu.Path = path.Join(t.endpoint(), cr.tr.ID.String())
+
+	if cr.lg != nil {
+		cr.lg.Debug(
+			"dial stream reader",
+			zap.String("from", cr.tr.ID.String()),
+			zap.String("to", cr.peerID.String()),
+			zap.String("address", uu.String()),
+		)
+	}
+	req, err := http.NewRequest("GET", uu.String(), nil)
+	if err != nil {
+		cr.picker.unreachable(u)
+		return nil, fmt.Errorf("failed to make http request to %v (%v)", u, err)
+	}
+	req.Header.Set("X-Server-From", cr.tr.ID.String())
+	req.Header.Set("X-Server-Version", version.Version)
+	req.Header.Set("X-Min-Cluster-Version", version.MinClusterVersion)
+	req.Header.Set("X-Etcd-Cluster-ID", cr.tr.ClusterID.String())
+	req.Header.Set("X-Raft-To", cr.peerID.String())
+
+	setPeerURLsHeader(req, cr.tr.URLs)
+
+	req = req.WithContext(cr.ctx)
+
+	cr.mu.Lock()
+	select {
+	case <-cr.ctx.Done():
+		cr.mu.Unlock()
+		return nil, fmt.Errorf("stream reader is stopped")
+	default:
+	}
+	cr.mu.Unlock()
+
+	resp, err := cr.tr.streamRt.RoundTrip(req)
+	if err != nil {
+		cr.picker.unreachable(u)
+		return nil, err
+	}
+
+	rv := serverVersion(resp.Header)
+	lv := semver.Must(semver.NewVersion(version.Version))
+	if compareMajorMinorVersion(rv, lv) == -1 && !checkStreamSupport(rv, t) {
+		httputil.GracefulClose(resp)
+		cr.picker.unreachable(u)
+		return nil, errUnsupportedStreamType
+	}
+
+	switch resp.StatusCode {
+	case http.StatusGone:
+		httputil.GracefulClose(resp)
+		cr.picker.unreachable(u)
+		reportCriticalError(errMemberRemoved, cr.errorc)
+		return nil, errMemberRemoved
+
+	case http.StatusOK:
+		return resp.Body, nil
+
+	case http.StatusNotFound:
+		httputil.GracefulClose(resp)
+		cr.picker.unreachable(u)
+		return nil, fmt.Errorf("peer %s failed to find local node %s", cr.peerID, cr.tr.ID)
+
+	case http.StatusPreconditionFailed:
+		b, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			cr.picker.unreachable(u)
+			return nil, err
+		}
+		httputil.GracefulClose(resp)
+		cr.picker.unreachable(u)
+
+		switch strings.TrimSuffix(string(b), "\n") {
+		case errIncompatibleVersion.Error():
+			if cr.lg != nil {
+				cr.lg.Warn(
+					"request sent was ignored by remote peer due to server version incompatibility",
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+					zap.Error(errIncompatibleVersion),
+				)
+			} else {
+				plog.Errorf("request sent was ignored by peer %s (server version incompatible)", cr.peerID)
+			}
+			return nil, errIncompatibleVersion
+
+		case errClusterIDMismatch.Error():
+			if cr.lg != nil {
+				cr.lg.Warn(
+					"request sent was ignored by remote peer due to cluster ID mismatch",
+					zap.String("remote-peer-id", cr.peerID.String()),
+					zap.String("remote-peer-cluster-id", resp.Header.Get("X-Etcd-Cluster-ID")),
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("local-member-cluster-id", cr.tr.ClusterID.String()),
+					zap.Error(errClusterIDMismatch),
+				)
+			} else {
+				plog.Errorf("request sent was ignored (cluster ID mismatch: peer[%s]=%s, local=%s)",
+					cr.peerID, resp.Header.Get("X-Etcd-Cluster-ID"), cr.tr.ClusterID)
+			}
+			return nil, errClusterIDMismatch
+
+		default:
+			return nil, fmt.Errorf("unhandled error %q when precondition failed", string(b))
+		}
+
+	default:
+		httputil.GracefulClose(resp)
+		cr.picker.unreachable(u)
+		return nil, fmt.Errorf("unhandled http status %d", resp.StatusCode)
+	}
+}
+
+func (cr *streamReader) close() {
+	if cr.closer != nil {
+		if err := cr.closer.Close(); err != nil {
+			if cr.lg != nil {
+				cr.lg.Warn(
+					"failed to close remote peer connection",
+					zap.String("local-member-id", cr.tr.ID.String()),
+					zap.String("remote-peer-id", cr.peerID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("peer %s (reader) connection close error: %v", cr.peerID, err)
+			}
+		}
+	}
+	cr.closer = nil
+}
+
+func (cr *streamReader) pause() {
+	cr.mu.Lock()
+	defer cr.mu.Unlock()
+	cr.paused = true
+}
+
+func (cr *streamReader) resume() {
+	cr.mu.Lock()
+	defer cr.mu.Unlock()
+	cr.paused = false
+}
+
+// checkStreamSupport checks whether the stream type is supported in the
+// given version.
+func checkStreamSupport(v *semver.Version, t streamType) bool {
+	nv := &semver.Version{Major: v.Major, Minor: v.Minor}
+	for _, s := range supportedStream[nv.String()] {
+		if s == t {
+			return true
+		}
+	}
+	return false
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/transport.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/transport.go
new file mode 100644
index 0000000..7191c3d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/transport.go
@@ -0,0 +1,467 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"context"
+	"net/http"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/pkg/logutil"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"github.com/coreos/pkg/capnslog"
+	"github.com/xiang90/probing"
+	"go.uber.org/zap"
+	"golang.org/x/time/rate"
+)
+
+var plog = logutil.NewMergeLogger(capnslog.NewPackageLogger("go.etcd.io/etcd", "rafthttp"))
+
+type Raft interface {
+	Process(ctx context.Context, m raftpb.Message) error
+	IsIDRemoved(id uint64) bool
+	ReportUnreachable(id uint64)
+	ReportSnapshot(id uint64, status raft.SnapshotStatus)
+}
+
+type Transporter interface {
+	// Start starts the given Transporter.
+	// Start MUST be called before calling other functions in the interface.
+	Start() error
+	// Handler returns the HTTP handler of the transporter.
+	// A transporter HTTP handler handles the HTTP requests
+	// from remote peers.
+	// The handler MUST be used to handle RaftPrefix(/raft)
+	// endpoint.
+	Handler() http.Handler
+	// Send sends out the given messages to the remote peers.
+	// Each message has a To field, which is an id that maps
+	// to an existing peer in the transport.
+	// If the id cannot be found in the transport, the message
+	// will be ignored.
+	Send(m []raftpb.Message)
+	// SendSnapshot sends out the given snapshot message to a remote peer.
+	// The behavior of SendSnapshot is similar to Send.
+	SendSnapshot(m snap.Message)
+	// AddRemote adds a remote with given peer urls into the transport.
+	// A remote helps newly joined member to catch up the progress of cluster,
+	// and will not be used after that.
+	// It is the caller's responsibility to ensure the urls are all valid,
+	// or it panics.
+	AddRemote(id types.ID, urls []string)
+	// AddPeer adds a peer with given peer urls into the transport.
+	// It is the caller's responsibility to ensure the urls are all valid,
+	// or it panics.
+	// Peer urls are used to connect to the remote peer.
+	AddPeer(id types.ID, urls []string)
+	// RemovePeer removes the peer with given id.
+	RemovePeer(id types.ID)
+	// RemoveAllPeers removes all the existing peers in the transport.
+	RemoveAllPeers()
+	// UpdatePeer updates the peer urls of the peer with the given id.
+	// It is the caller's responsibility to ensure the urls are all valid,
+	// or it panics.
+	UpdatePeer(id types.ID, urls []string)
+	// ActiveSince returns the time that the connection with the peer
+	// of the given id becomes active.
+	// If the connection is active since peer was added, it returns the adding time.
+	// If the connection is currently inactive, it returns zero time.
+	ActiveSince(id types.ID) time.Time
+	// ActivePeers returns the number of active peers.
+	ActivePeers() int
+	// Stop closes the connections and stops the transporter.
+	Stop()
+}
+
+// Transport implements Transporter interface. It provides the functionality
+// to send raft messages to peers, and receive raft messages from peers.
+// User should call Handler method to get a handler to serve requests
+// received from peerURLs.
+// User needs to call Start before calling other functions, and call
+// Stop when the Transport is no longer used.
+type Transport struct {
+	Logger *zap.Logger
+
+	DialTimeout time.Duration // maximum duration before timing out dial of the request
+	// DialRetryFrequency defines the frequency of streamReader dial retrial attempts;
+	// a distinct rate limiter is created per every peer (default value: 10 events/sec)
+	DialRetryFrequency rate.Limit
+
+	TLSInfo transport.TLSInfo // TLS information used when creating connection
+
+	ID          types.ID   // local member ID
+	URLs        types.URLs // local peer URLs
+	ClusterID   types.ID   // raft cluster ID for request validation
+	Raft        Raft       // raft state machine, to which the Transport forwards received messages and reports status
+	Snapshotter *snap.Snapshotter
+	ServerStats *stats.ServerStats // used to record general transportation statistics
+	// used to record transportation statistics with followers when
+	// performing as leader in raft protocol
+	LeaderStats *stats.LeaderStats
+	// ErrorC is used to report detected critical errors, e.g.,
+	// the member has been permanently removed from the cluster
+	// When an error is received from ErrorC, user should stop raft state
+	// machine and thus stop the Transport.
+	ErrorC chan error
+
+	streamRt   http.RoundTripper // roundTripper used by streams
+	pipelineRt http.RoundTripper // roundTripper used by pipelines
+
+	mu      sync.RWMutex         // protect the remote and peer map
+	remotes map[types.ID]*remote // remotes map that helps newly joined member to catch up
+	peers   map[types.ID]Peer    // peers map
+
+	pipelineProber probing.Prober
+	streamProber   probing.Prober
+}
+
+func (t *Transport) Start() error {
+	var err error
+	t.streamRt, err = newStreamRoundTripper(t.TLSInfo, t.DialTimeout)
+	if err != nil {
+		return err
+	}
+	t.pipelineRt, err = NewRoundTripper(t.TLSInfo, t.DialTimeout)
+	if err != nil {
+		return err
+	}
+	t.remotes = make(map[types.ID]*remote)
+	t.peers = make(map[types.ID]Peer)
+	t.pipelineProber = probing.NewProber(t.pipelineRt)
+	t.streamProber = probing.NewProber(t.streamRt)
+
+	// If client didn't provide dial retry frequency, use the default
+	// (100ms backoff between attempts to create a new stream),
+	// so it doesn't bring too much overhead when retry.
+	if t.DialRetryFrequency == 0 {
+		t.DialRetryFrequency = rate.Every(100 * time.Millisecond)
+	}
+	return nil
+}
+
+func (t *Transport) Handler() http.Handler {
+	pipelineHandler := newPipelineHandler(t, t.Raft, t.ClusterID)
+	streamHandler := newStreamHandler(t, t, t.Raft, t.ID, t.ClusterID)
+	snapHandler := newSnapshotHandler(t, t.Raft, t.Snapshotter, t.ClusterID)
+	mux := http.NewServeMux()
+	mux.Handle(RaftPrefix, pipelineHandler)
+	mux.Handle(RaftStreamPrefix+"/", streamHandler)
+	mux.Handle(RaftSnapshotPrefix, snapHandler)
+	mux.Handle(ProbingPrefix, probing.NewHandler())
+	return mux
+}
+
+func (t *Transport) Get(id types.ID) Peer {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	return t.peers[id]
+}
+
+func (t *Transport) Send(msgs []raftpb.Message) {
+	for _, m := range msgs {
+		if m.To == 0 {
+			// ignore intentionally dropped message
+			continue
+		}
+		to := types.ID(m.To)
+
+		t.mu.RLock()
+		p, pok := t.peers[to]
+		g, rok := t.remotes[to]
+		t.mu.RUnlock()
+
+		if pok {
+			if m.Type == raftpb.MsgApp {
+				t.ServerStats.SendAppendReq(m.Size())
+			}
+			p.send(m)
+			continue
+		}
+
+		if rok {
+			g.send(m)
+			continue
+		}
+
+		if t.Logger != nil {
+			t.Logger.Debug(
+				"ignored message send request; unknown remote peer target",
+				zap.String("type", m.Type.String()),
+				zap.String("unknown-target-peer-id", to.String()),
+			)
+		} else {
+			plog.Debugf("ignored message %s (sent to unknown peer %s)", m.Type, to)
+		}
+	}
+}
+
+func (t *Transport) Stop() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	for _, r := range t.remotes {
+		r.stop()
+	}
+	for _, p := range t.peers {
+		p.stop()
+	}
+	t.pipelineProber.RemoveAll()
+	t.streamProber.RemoveAll()
+	if tr, ok := t.streamRt.(*http.Transport); ok {
+		tr.CloseIdleConnections()
+	}
+	if tr, ok := t.pipelineRt.(*http.Transport); ok {
+		tr.CloseIdleConnections()
+	}
+	t.peers = nil
+	t.remotes = nil
+}
+
+// CutPeer drops messages to the specified peer.
+func (t *Transport) CutPeer(id types.ID) {
+	t.mu.RLock()
+	p, pok := t.peers[id]
+	g, gok := t.remotes[id]
+	t.mu.RUnlock()
+
+	if pok {
+		p.(Pausable).Pause()
+	}
+	if gok {
+		g.Pause()
+	}
+}
+
+// MendPeer recovers the message dropping behavior of the given peer.
+func (t *Transport) MendPeer(id types.ID) {
+	t.mu.RLock()
+	p, pok := t.peers[id]
+	g, gok := t.remotes[id]
+	t.mu.RUnlock()
+
+	if pok {
+		p.(Pausable).Resume()
+	}
+	if gok {
+		g.Resume()
+	}
+}
+
+func (t *Transport) AddRemote(id types.ID, us []string) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.remotes == nil {
+		// there's no clean way to shutdown the golang http server
+		// (see: https://github.com/golang/go/issues/4674) before
+		// stopping the transport; ignore any new connections.
+		return
+	}
+	if _, ok := t.peers[id]; ok {
+		return
+	}
+	if _, ok := t.remotes[id]; ok {
+		return
+	}
+	urls, err := types.NewURLs(us)
+	if err != nil {
+		if t.Logger != nil {
+			t.Logger.Panic("failed NewURLs", zap.Strings("urls", us), zap.Error(err))
+		} else {
+			plog.Panicf("newURLs %+v should never fail: %+v", us, err)
+		}
+	}
+	t.remotes[id] = startRemote(t, urls, id)
+
+	if t.Logger != nil {
+		t.Logger.Info(
+			"added new remote peer",
+			zap.String("local-member-id", t.ID.String()),
+			zap.String("remote-peer-id", id.String()),
+			zap.Strings("remote-peer-urls", us),
+		)
+	}
+}
+
+func (t *Transport) AddPeer(id types.ID, us []string) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.peers == nil {
+		panic("transport stopped")
+	}
+	if _, ok := t.peers[id]; ok {
+		return
+	}
+	urls, err := types.NewURLs(us)
+	if err != nil {
+		if t.Logger != nil {
+			t.Logger.Panic("failed NewURLs", zap.Strings("urls", us), zap.Error(err))
+		} else {
+			plog.Panicf("newURLs %+v should never fail: %+v", us, err)
+		}
+	}
+	fs := t.LeaderStats.Follower(id.String())
+	t.peers[id] = startPeer(t, urls, id, fs)
+	addPeerToProber(t.Logger, t.pipelineProber, id.String(), us, RoundTripperNameSnapshot, rttSec)
+	addPeerToProber(t.Logger, t.streamProber, id.String(), us, RoundTripperNameRaftMessage, rttSec)
+
+	if t.Logger != nil {
+		t.Logger.Info(
+			"added remote peer",
+			zap.String("local-member-id", t.ID.String()),
+			zap.String("remote-peer-id", id.String()),
+			zap.Strings("remote-peer-urls", us),
+		)
+	} else {
+		plog.Infof("added peer %s", id)
+	}
+}
+
+func (t *Transport) RemovePeer(id types.ID) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.removePeer(id)
+}
+
+func (t *Transport) RemoveAllPeers() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	for id := range t.peers {
+		t.removePeer(id)
+	}
+}
+
+// the caller of this function must have the peers mutex.
+func (t *Transport) removePeer(id types.ID) {
+	if peer, ok := t.peers[id]; ok {
+		peer.stop()
+	} else {
+		if t.Logger != nil {
+			t.Logger.Panic("unexpected removal of unknown remote peer", zap.String("remote-peer-id", id.String()))
+		} else {
+			plog.Panicf("unexpected removal of unknown peer '%d'", id)
+		}
+	}
+	delete(t.peers, id)
+	delete(t.LeaderStats.Followers, id.String())
+	t.pipelineProber.Remove(id.String())
+	t.streamProber.Remove(id.String())
+
+	if t.Logger != nil {
+		t.Logger.Info(
+			"removed remote peer",
+			zap.String("local-member-id", t.ID.String()),
+			zap.String("removed-remote-peer-id", id.String()),
+		)
+	} else {
+		plog.Infof("removed peer %s", id)
+	}
+}
+
+func (t *Transport) UpdatePeer(id types.ID, us []string) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	// TODO: return error or just panic?
+	if _, ok := t.peers[id]; !ok {
+		return
+	}
+	urls, err := types.NewURLs(us)
+	if err != nil {
+		if t.Logger != nil {
+			t.Logger.Panic("failed NewURLs", zap.Strings("urls", us), zap.Error(err))
+		} else {
+			plog.Panicf("newURLs %+v should never fail: %+v", us, err)
+		}
+	}
+	t.peers[id].update(urls)
+
+	t.pipelineProber.Remove(id.String())
+	addPeerToProber(t.Logger, t.pipelineProber, id.String(), us, RoundTripperNameSnapshot, rttSec)
+	t.streamProber.Remove(id.String())
+	addPeerToProber(t.Logger, t.streamProber, id.String(), us, RoundTripperNameRaftMessage, rttSec)
+
+	if t.Logger != nil {
+		t.Logger.Info(
+			"updated remote peer",
+			zap.String("local-member-id", t.ID.String()),
+			zap.String("updated-remote-peer-id", id.String()),
+			zap.Strings("updated-remote-peer-urls", us),
+		)
+	} else {
+		plog.Infof("updated peer %s", id)
+	}
+}
+
+func (t *Transport) ActiveSince(id types.ID) time.Time {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	if p, ok := t.peers[id]; ok {
+		return p.activeSince()
+	}
+	return time.Time{}
+}
+
+func (t *Transport) SendSnapshot(m snap.Message) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	p := t.peers[types.ID(m.To)]
+	if p == nil {
+		m.CloseWithError(errMemberNotFound)
+		return
+	}
+	p.sendSnap(m)
+}
+
+// Pausable is a testing interface for pausing transport traffic.
+type Pausable interface {
+	Pause()
+	Resume()
+}
+
+func (t *Transport) Pause() {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	for _, p := range t.peers {
+		p.(Pausable).Pause()
+	}
+}
+
+func (t *Transport) Resume() {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	for _, p := range t.peers {
+		p.(Pausable).Resume()
+	}
+}
+
+// ActivePeers returns a channel that closes when an initial
+// peer connection has been established. Use this to wait until the
+// first peer connection becomes active.
+func (t *Transport) ActivePeers() (cnt int) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	for _, p := range t.peers {
+		if !p.activeSince().IsZero() {
+			cnt++
+		}
+	}
+	return cnt
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/urlpick.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/urlpick.go
new file mode 100644
index 0000000..61ef468
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/urlpick.go
@@ -0,0 +1,57 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"net/url"
+	"sync"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+type urlPicker struct {
+	mu     sync.Mutex // guards urls and picked
+	urls   types.URLs
+	picked int
+}
+
+func newURLPicker(urls types.URLs) *urlPicker {
+	return &urlPicker{
+		urls: urls,
+	}
+}
+
+func (p *urlPicker) update(urls types.URLs) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.urls = urls
+	p.picked = 0
+}
+
+func (p *urlPicker) pick() url.URL {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.urls[p.picked]
+}
+
+// unreachable notices the picker that the given url is unreachable,
+// and it should use other possible urls.
+func (p *urlPicker) unreachable(u url.URL) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if u == p.urls[p.picked] {
+		p.picked = (p.picked + 1) % len(p.urls)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/util.go b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/util.go
new file mode 100644
index 0000000..2093864
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/rafthttp/util.go
@@ -0,0 +1,190 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rafthttp
+
+import (
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+var (
+	errMemberRemoved  = fmt.Errorf("the member has been permanently removed from the cluster")
+	errMemberNotFound = fmt.Errorf("member not found")
+)
+
+// NewListener returns a listener for raft message transfer between peers.
+// It uses timeout listener to identify broken streams promptly.
+func NewListener(u url.URL, tlsinfo *transport.TLSInfo) (net.Listener, error) {
+	return transport.NewTimeoutListener(u.Host, u.Scheme, tlsinfo, ConnReadTimeout, ConnWriteTimeout)
+}
+
+// NewRoundTripper returns a roundTripper used to send requests
+// to rafthttp listener of remote peers.
+func NewRoundTripper(tlsInfo transport.TLSInfo, dialTimeout time.Duration) (http.RoundTripper, error) {
+	// It uses timeout transport to pair with remote timeout listeners.
+	// It sets no read/write timeout, because message in requests may
+	// take long time to write out before reading out the response.
+	return transport.NewTimeoutTransport(tlsInfo, dialTimeout, 0, 0)
+}
+
+// newStreamRoundTripper returns a roundTripper used to send stream requests
+// to rafthttp listener of remote peers.
+// Read/write timeout is set for stream roundTripper to promptly
+// find out broken status, which minimizes the number of messages
+// sent on broken connection.
+func newStreamRoundTripper(tlsInfo transport.TLSInfo, dialTimeout time.Duration) (http.RoundTripper, error) {
+	return transport.NewTimeoutTransport(tlsInfo, dialTimeout, ConnReadTimeout, ConnWriteTimeout)
+}
+
+// createPostRequest creates a HTTP POST request that sends raft message.
+func createPostRequest(u url.URL, path string, body io.Reader, ct string, urls types.URLs, from, cid types.ID) *http.Request {
+	uu := u
+	uu.Path = path
+	req, err := http.NewRequest("POST", uu.String(), body)
+	if err != nil {
+		plog.Panicf("unexpected new request error (%v)", err)
+	}
+	req.Header.Set("Content-Type", ct)
+	req.Header.Set("X-Server-From", from.String())
+	req.Header.Set("X-Server-Version", version.Version)
+	req.Header.Set("X-Min-Cluster-Version", version.MinClusterVersion)
+	req.Header.Set("X-Etcd-Cluster-ID", cid.String())
+	setPeerURLsHeader(req, urls)
+
+	return req
+}
+
+// checkPostResponse checks the response of the HTTP POST request that sends
+// raft message.
+func checkPostResponse(resp *http.Response, body []byte, req *http.Request, to types.ID) error {
+	switch resp.StatusCode {
+	case http.StatusPreconditionFailed:
+		switch strings.TrimSuffix(string(body), "\n") {
+		case errIncompatibleVersion.Error():
+			plog.Errorf("request sent was ignored by peer %s (server version incompatible)", to)
+			return errIncompatibleVersion
+		case errClusterIDMismatch.Error():
+			plog.Errorf("request sent was ignored (cluster ID mismatch: remote[%s]=%s, local=%s)",
+				to, resp.Header.Get("X-Etcd-Cluster-ID"), req.Header.Get("X-Etcd-Cluster-ID"))
+			return errClusterIDMismatch
+		default:
+			return fmt.Errorf("unhandled error %q when precondition failed", string(body))
+		}
+	case http.StatusForbidden:
+		return errMemberRemoved
+	case http.StatusNoContent:
+		return nil
+	default:
+		return fmt.Errorf("unexpected http status %s while posting to %q", http.StatusText(resp.StatusCode), req.URL.String())
+	}
+}
+
+// reportCriticalError reports the given error through sending it into
+// the given error channel.
+// If the error channel is filled up when sending error, it drops the error
+// because the fact that error has happened is reported, which is
+// good enough.
+func reportCriticalError(err error, errc chan<- error) {
+	select {
+	case errc <- err:
+	default:
+	}
+}
+
+// compareMajorMinorVersion returns an integer comparing two versions based on
+// their major and minor version. The result will be 0 if a==b, -1 if a < b,
+// and 1 if a > b.
+func compareMajorMinorVersion(a, b *semver.Version) int {
+	na := &semver.Version{Major: a.Major, Minor: a.Minor}
+	nb := &semver.Version{Major: b.Major, Minor: b.Minor}
+	switch {
+	case na.LessThan(*nb):
+		return -1
+	case nb.LessThan(*na):
+		return 1
+	default:
+		return 0
+	}
+}
+
+// serverVersion returns the server version from the given header.
+func serverVersion(h http.Header) *semver.Version {
+	verStr := h.Get("X-Server-Version")
+	// backward compatibility with etcd 2.0
+	if verStr == "" {
+		verStr = "2.0.0"
+	}
+	return semver.Must(semver.NewVersion(verStr))
+}
+
+// serverVersion returns the min cluster version from the given header.
+func minClusterVersion(h http.Header) *semver.Version {
+	verStr := h.Get("X-Min-Cluster-Version")
+	// backward compatibility with etcd 2.0
+	if verStr == "" {
+		verStr = "2.0.0"
+	}
+	return semver.Must(semver.NewVersion(verStr))
+}
+
+// checkVersionCompatibility checks whether the given version is compatible
+// with the local version.
+func checkVersionCompatibility(name string, server, minCluster *semver.Version) (
+	localServer *semver.Version,
+	localMinCluster *semver.Version,
+	err error) {
+	localServer = semver.Must(semver.NewVersion(version.Version))
+	localMinCluster = semver.Must(semver.NewVersion(version.MinClusterVersion))
+	if compareMajorMinorVersion(server, localMinCluster) == -1 {
+		return localServer, localMinCluster, fmt.Errorf("remote version is too low: remote[%s]=%s, local=%s", name, server, localServer)
+	}
+	if compareMajorMinorVersion(minCluster, localServer) == 1 {
+		return localServer, localMinCluster, fmt.Errorf("local version is too low: remote[%s]=%s, local=%s", name, server, localServer)
+	}
+	return localServer, localMinCluster, nil
+}
+
+// setPeerURLsHeader reports local urls for peer discovery
+func setPeerURLsHeader(req *http.Request, urls types.URLs) {
+	if urls == nil {
+		// often not set in unit tests
+		return
+	}
+	peerURLs := make([]string, urls.Len())
+	for i := range urls {
+		peerURLs[i] = urls[i].String()
+	}
+	req.Header.Set("X-PeerURLs", strings.Join(peerURLs, ","))
+}
+
+// addRemoteFromRequest adds a remote peer according to an http request header
+func addRemoteFromRequest(tr Transporter, r *http.Request) {
+	if from, err := types.IDFromString(r.Header.Get("X-Server-From")); err == nil {
+		if urls := r.Header.Get("X-PeerURLs"); urls != "" {
+			tr.AddRemote(from, strings.Split(urls, ","))
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/db.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/db.go
new file mode 100644
index 0000000..3002ccd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/db.go
@@ -0,0 +1,104 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package snap
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+
+	humanize "github.com/dustin/go-humanize"
+	"go.uber.org/zap"
+)
+
+var ErrNoDBSnapshot = errors.New("snap: snapshot file doesn't exist")
+
+// SaveDBFrom saves snapshot of the database from the given reader. It
+// guarantees the save operation is atomic.
+func (s *Snapshotter) SaveDBFrom(r io.Reader, id uint64) (int64, error) {
+	start := time.Now()
+
+	f, err := ioutil.TempFile(s.dir, "tmp")
+	if err != nil {
+		return 0, err
+	}
+	var n int64
+	n, err = io.Copy(f, r)
+	if err == nil {
+		fsyncStart := time.Now()
+		err = fileutil.Fsync(f)
+		snapDBFsyncSec.Observe(time.Since(fsyncStart).Seconds())
+	}
+	f.Close()
+	if err != nil {
+		os.Remove(f.Name())
+		return n, err
+	}
+	fn := s.dbFilePath(id)
+	if fileutil.Exist(fn) {
+		os.Remove(f.Name())
+		return n, nil
+	}
+	err = os.Rename(f.Name(), fn)
+	if err != nil {
+		os.Remove(f.Name())
+		return n, err
+	}
+
+	if s.lg != nil {
+		s.lg.Info(
+			"saved database snapshot to disk",
+			zap.String("path", fn),
+			zap.Int64("bytes", n),
+			zap.String("size", humanize.Bytes(uint64(n))),
+		)
+	} else {
+		plog.Infof("saved database snapshot to disk [total bytes: %d]", n)
+	}
+
+	snapDBSaveSec.Observe(time.Since(start).Seconds())
+	return n, nil
+}
+
+// DBFilePath returns the file path for the snapshot of the database with
+// given id. If the snapshot does not exist, it returns error.
+func (s *Snapshotter) DBFilePath(id uint64) (string, error) {
+	if _, err := fileutil.ReadDir(s.dir); err != nil {
+		return "", err
+	}
+	fn := s.dbFilePath(id)
+	if fileutil.Exist(fn) {
+		return fn, nil
+	}
+	if s.lg != nil {
+		s.lg.Warn(
+			"failed to find [SNAPSHOT-INDEX].snap.db",
+			zap.Uint64("snapshot-index", id),
+			zap.String("snapshot-file-path", fn),
+			zap.Error(ErrNoDBSnapshot),
+		)
+	}
+	return "", ErrNoDBSnapshot
+}
+
+func (s *Snapshotter) dbFilePath(id uint64) string {
+	return filepath.Join(s.dir, fmt.Sprintf("%016x.snap.db", id))
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/doc.go
new file mode 100644
index 0000000..dcc5db5
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/doc.go
@@ -0,0 +1,17 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package snap handles Raft nodes' states with snapshots.
+// The snapshot logic is internal to etcd server and raft package.
+package snap
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/message.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/message.go
new file mode 100644
index 0000000..c1151e2
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/message.go
@@ -0,0 +1,64 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package snap
+
+import (
+	"io"
+
+	"go.etcd.io/etcd/pkg/ioutil"
+	"go.etcd.io/etcd/raft/raftpb"
+)
+
+// Message is a struct that contains a raft Message and a ReadCloser. The type
+// of raft message MUST be MsgSnap, which contains the raft meta-data and an
+// additional data []byte field that contains the snapshot of the actual state
+// machine.
+// Message contains the ReadCloser field for handling large snapshot. This avoid
+// copying the entire snapshot into a byte array, which consumes a lot of memory.
+//
+// User of Message should close the Message after sending it.
+type Message struct {
+	raftpb.Message
+	ReadCloser io.ReadCloser
+	TotalSize  int64
+	closeC     chan bool
+}
+
+func NewMessage(rs raftpb.Message, rc io.ReadCloser, rcSize int64) *Message {
+	return &Message{
+		Message:    rs,
+		ReadCloser: ioutil.NewExactReadCloser(rc, rcSize),
+		TotalSize:  int64(rs.Size()) + rcSize,
+		closeC:     make(chan bool, 1),
+	}
+}
+
+// CloseNotify returns a channel that receives a single value
+// when the message sent is finished. true indicates the sent
+// is successful.
+func (m Message) CloseNotify() <-chan bool {
+	return m.closeC
+}
+
+func (m Message) CloseWithError(err error) {
+	if cerr := m.ReadCloser.Close(); cerr != nil {
+		err = cerr
+	}
+	if err == nil {
+		m.closeC <- true
+	} else {
+		m.closeC <- false
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/metrics.go
new file mode 100644
index 0000000..2affecf
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/metrics.go
@@ -0,0 +1,82 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package snap
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	snapMarshallingSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "snap",
+		Name:      "save_marshalling_duration_seconds",
+		Help:      "The marshalling cost distributions of save called by snapshot.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	snapSaveSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "snap",
+		Name:      "save_total_duration_seconds",
+		Help:      "The total latency distributions of save called by snapshot.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	snapFsyncSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "snap",
+		Name:      "fsync_duration_seconds",
+		Help:      "The latency distributions of fsync called by snap.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	snapDBSaveSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "snap_db",
+		Name:      "save_total_duration_seconds",
+		Help:      "The total latency distributions of v3 snapshot save",
+
+		// lowest bucket start of upper bound 0.1 sec (100 ms) with factor 2
+		// highest bucket start of 0.1 sec * 2^9 == 51.2 sec
+		Buckets: prometheus.ExponentialBuckets(0.1, 2, 10),
+	})
+
+	snapDBFsyncSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "snap_db",
+		Name:      "fsync_duration_seconds",
+		Help:      "The latency distributions of fsyncing .snap.db file",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+)
+
+func init() {
+	prometheus.MustRegister(snapMarshallingSec)
+	prometheus.MustRegister(snapSaveSec)
+	prometheus.MustRegister(snapFsyncSec)
+	prometheus.MustRegister(snapDBSaveSec)
+	prometheus.MustRegister(snapDBFsyncSec)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.pb.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.pb.go
new file mode 100644
index 0000000..e72b577
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.pb.go
@@ -0,0 +1,336 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: snap.proto
+
+/*
+	Package snappb is a generated protocol buffer package.
+
+	It is generated from these files:
+		snap.proto
+
+	It has these top-level messages:
+		Snapshot
+*/
+package snappb
+
+import (
+	"fmt"
+
+	proto "github.com/golang/protobuf/proto"
+
+	math "math"
+
+	_ "github.com/gogo/protobuf/gogoproto"
+
+	io "io"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type Snapshot struct {
+	Crc              uint32 `protobuf:"varint,1,opt,name=crc" json:"crc"`
+	Data             []byte `protobuf:"bytes,2,opt,name=data" json:"data,omitempty"`
+	XXX_unrecognized []byte `json:"-"`
+}
+
+func (m *Snapshot) Reset()                    { *m = Snapshot{} }
+func (m *Snapshot) String() string            { return proto.CompactTextString(m) }
+func (*Snapshot) ProtoMessage()               {}
+func (*Snapshot) Descriptor() ([]byte, []int) { return fileDescriptorSnap, []int{0} }
+
+func init() {
+	proto.RegisterType((*Snapshot)(nil), "snappb.snapshot")
+}
+func (m *Snapshot) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Snapshot) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	dAtA[i] = 0x8
+	i++
+	i = encodeVarintSnap(dAtA, i, uint64(m.Crc))
+	if m.Data != nil {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintSnap(dAtA, i, uint64(len(m.Data)))
+		i += copy(dAtA[i:], m.Data)
+	}
+	if m.XXX_unrecognized != nil {
+		i += copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	return i, nil
+}
+
+func encodeVarintSnap(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *Snapshot) Size() (n int) {
+	var l int
+	_ = l
+	n += 1 + sovSnap(uint64(m.Crc))
+	if m.Data != nil {
+		l = len(m.Data)
+		n += 1 + l + sovSnap(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func sovSnap(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozSnap(x uint64) (n int) {
+	return sovSnap(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *Snapshot) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowSnap
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: snapshot: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: snapshot: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Crc", wireType)
+			}
+			m.Crc = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowSnap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Crc |= (uint32(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Data", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowSnap
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthSnap
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Data = append(m.Data[:0], dAtA[iNdEx:postIndex]...)
+			if m.Data == nil {
+				m.Data = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipSnap(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthSnap
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipSnap(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowSnap
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowSnap
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowSnap
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthSnap
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowSnap
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipSnap(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthSnap = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowSnap   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("snap.proto", fileDescriptorSnap) }
+
+var fileDescriptorSnap = []byte{
+	// 126 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x2a, 0xce, 0x4b, 0x2c,
+	0xd0, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x03, 0xb1, 0x0b, 0x92, 0xa4, 0x44, 0xd2, 0xf3,
+	0xd3, 0xf3, 0xc1, 0x42, 0xfa, 0x20, 0x16, 0x44, 0x56, 0xc9, 0x8c, 0x8b, 0x03, 0x24, 0x5f, 0x9c,
+	0x91, 0x5f, 0x22, 0x24, 0xc6, 0xc5, 0x9c, 0x5c, 0x94, 0x2c, 0xc1, 0xa8, 0xc0, 0xa8, 0xc1, 0xeb,
+	0xc4, 0x72, 0xe2, 0x9e, 0x3c, 0x43, 0x10, 0x48, 0x40, 0x48, 0x88, 0x8b, 0x25, 0x25, 0xb1, 0x24,
+	0x51, 0x82, 0x49, 0x81, 0x51, 0x83, 0x27, 0x08, 0xcc, 0x76, 0x12, 0x39, 0xf1, 0x50, 0x8e, 0xe1,
+	0xc4, 0x23, 0x39, 0xc6, 0x0b, 0x8f, 0xe4, 0x18, 0x1f, 0x3c, 0x92, 0x63, 0x9c, 0xf1, 0x58, 0x8e,
+	0x01, 0x10, 0x00, 0x00, 0xff, 0xff, 0xd8, 0x0f, 0x32, 0xb2, 0x78, 0x00, 0x00, 0x00,
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.proto b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.proto
new file mode 100644
index 0000000..cd3d21d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snappb/snap.proto
@@ -0,0 +1,14 @@
+syntax = "proto2";
+package snappb;
+
+import "gogoproto/gogo.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_getters_all) = false;
+
+message snapshot {
+	optional uint32 crc  = 1 [(gogoproto.nullable) = false];
+	optional bytes data  = 2;
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/snap/snapshotter.go b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snapshotter.go
new file mode 100644
index 0000000..7e79333
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/snap/snapshotter.go
@@ -0,0 +1,255 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package snap
+
+import (
+	"errors"
+	"fmt"
+	"hash/crc32"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap/snappb"
+	pioutil "go.etcd.io/etcd/pkg/ioutil"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+)
+
+const snapSuffix = ".snap"
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd/v3", "snap")
+
+	ErrNoSnapshot    = errors.New("snap: no available snapshot")
+	ErrEmptySnapshot = errors.New("snap: empty snapshot")
+	ErrCRCMismatch   = errors.New("snap: crc mismatch")
+	crcTable         = crc32.MakeTable(crc32.Castagnoli)
+
+	// A map of valid files that can be present in the snap folder.
+	validFiles = map[string]bool{
+		"db": true,
+	}
+)
+
+type Snapshotter struct {
+	lg  *zap.Logger
+	dir string
+}
+
+func New(lg *zap.Logger, dir string) *Snapshotter {
+	return &Snapshotter{
+		lg:  lg,
+		dir: dir,
+	}
+}
+
+func (s *Snapshotter) SaveSnap(snapshot raftpb.Snapshot) error {
+	if raft.IsEmptySnap(snapshot) {
+		return nil
+	}
+	return s.save(&snapshot)
+}
+
+func (s *Snapshotter) save(snapshot *raftpb.Snapshot) error {
+	start := time.Now()
+
+	fname := fmt.Sprintf("%016x-%016x%s", snapshot.Metadata.Term, snapshot.Metadata.Index, snapSuffix)
+	b := pbutil.MustMarshal(snapshot)
+	crc := crc32.Update(0, crcTable, b)
+	snap := snappb.Snapshot{Crc: crc, Data: b}
+	d, err := snap.Marshal()
+	if err != nil {
+		return err
+	}
+	snapMarshallingSec.Observe(time.Since(start).Seconds())
+
+	spath := filepath.Join(s.dir, fname)
+
+	fsyncStart := time.Now()
+	err = pioutil.WriteAndSyncFile(spath, d, 0666)
+	snapFsyncSec.Observe(time.Since(fsyncStart).Seconds())
+
+	if err != nil {
+		if s.lg != nil {
+			s.lg.Warn("failed to write a snap file", zap.String("path", spath), zap.Error(err))
+		}
+		rerr := os.Remove(spath)
+		if rerr != nil {
+			if s.lg != nil {
+				s.lg.Warn("failed to remove a broken snap file", zap.String("path", spath), zap.Error(err))
+			} else {
+				plog.Errorf("failed to remove broken snapshot file %s", spath)
+			}
+		}
+		return err
+	}
+
+	snapSaveSec.Observe(time.Since(start).Seconds())
+	return nil
+}
+
+func (s *Snapshotter) Load() (*raftpb.Snapshot, error) {
+	names, err := s.snapNames()
+	if err != nil {
+		return nil, err
+	}
+	var snap *raftpb.Snapshot
+	for _, name := range names {
+		if snap, err = loadSnap(s.lg, s.dir, name); err == nil {
+			break
+		}
+	}
+	if err != nil {
+		return nil, ErrNoSnapshot
+	}
+	return snap, nil
+}
+
+func loadSnap(lg *zap.Logger, dir, name string) (*raftpb.Snapshot, error) {
+	fpath := filepath.Join(dir, name)
+	snap, err := Read(lg, fpath)
+	if err != nil {
+		brokenPath := fpath + ".broken"
+		if lg != nil {
+			lg.Warn("failed to read a snap file", zap.String("path", fpath), zap.Error(err))
+		}
+		if rerr := os.Rename(fpath, brokenPath); rerr != nil {
+			if lg != nil {
+				lg.Warn("failed to rename a broken snap file", zap.String("path", fpath), zap.String("broken-path", brokenPath), zap.Error(rerr))
+			} else {
+				plog.Warningf("cannot rename broken snapshot file %v to %v: %v", fpath, brokenPath, rerr)
+			}
+		} else {
+			if lg != nil {
+				lg.Warn("renamed to a broken snap file", zap.String("path", fpath), zap.String("broken-path", brokenPath))
+			}
+		}
+	}
+	return snap, err
+}
+
+// Read reads the snapshot named by snapname and returns the snapshot.
+func Read(lg *zap.Logger, snapname string) (*raftpb.Snapshot, error) {
+	b, err := ioutil.ReadFile(snapname)
+	if err != nil {
+		if lg != nil {
+			lg.Warn("failed to read a snap file", zap.String("path", snapname), zap.Error(err))
+		} else {
+			plog.Errorf("cannot read file %v: %v", snapname, err)
+		}
+		return nil, err
+	}
+
+	if len(b) == 0 {
+		if lg != nil {
+			lg.Warn("failed to read empty snapshot file", zap.String("path", snapname))
+		} else {
+			plog.Errorf("unexpected empty snapshot")
+		}
+		return nil, ErrEmptySnapshot
+	}
+
+	var serializedSnap snappb.Snapshot
+	if err = serializedSnap.Unmarshal(b); err != nil {
+		if lg != nil {
+			lg.Warn("failed to unmarshal snappb.Snapshot", zap.String("path", snapname), zap.Error(err))
+		} else {
+			plog.Errorf("corrupted snapshot file %v: %v", snapname, err)
+		}
+		return nil, err
+	}
+
+	if len(serializedSnap.Data) == 0 || serializedSnap.Crc == 0 {
+		if lg != nil {
+			lg.Warn("failed to read empty snapshot data", zap.String("path", snapname))
+		} else {
+			plog.Errorf("unexpected empty snapshot")
+		}
+		return nil, ErrEmptySnapshot
+	}
+
+	crc := crc32.Update(0, crcTable, serializedSnap.Data)
+	if crc != serializedSnap.Crc {
+		if lg != nil {
+			lg.Warn("snap file is corrupt",
+				zap.String("path", snapname),
+				zap.Uint32("prev-crc", serializedSnap.Crc),
+				zap.Uint32("new-crc", crc),
+			)
+		} else {
+			plog.Errorf("corrupted snapshot file %v: crc mismatch", snapname)
+		}
+		return nil, ErrCRCMismatch
+	}
+
+	var snap raftpb.Snapshot
+	if err = snap.Unmarshal(serializedSnap.Data); err != nil {
+		if lg != nil {
+			lg.Warn("failed to unmarshal raftpb.Snapshot", zap.String("path", snapname), zap.Error(err))
+		} else {
+			plog.Errorf("corrupted snapshot file %v: %v", snapname, err)
+		}
+		return nil, err
+	}
+	return &snap, nil
+}
+
+// snapNames returns the filename of the snapshots in logical time order (from newest to oldest).
+// If there is no available snapshots, an ErrNoSnapshot will be returned.
+func (s *Snapshotter) snapNames() ([]string, error) {
+	dir, err := os.Open(s.dir)
+	if err != nil {
+		return nil, err
+	}
+	defer dir.Close()
+	names, err := dir.Readdirnames(-1)
+	if err != nil {
+		return nil, err
+	}
+	snaps := checkSuffix(s.lg, names)
+	if len(snaps) == 0 {
+		return nil, ErrNoSnapshot
+	}
+	sort.Sort(sort.Reverse(sort.StringSlice(snaps)))
+	return snaps, nil
+}
+
+func checkSuffix(lg *zap.Logger, names []string) []string {
+	snaps := []string{}
+	for i := range names {
+		if strings.HasSuffix(names[i], snapSuffix) {
+			snaps = append(snaps, names[i])
+		} else {
+			// If we find a file which is not a snapshot then check if it's
+			// a vaild file. If not throw out a warning.
+			if _, ok := validFiles[names[i]]; !ok {
+				if lg != nil {
+					lg.Warn("found unexpected non-snap file; skipping", zap.String("path", names[i]))
+				} else {
+					plog.Warningf("skipped unexpected non snapshot file %v", names[i])
+				}
+			}
+		}
+	}
+	return snaps
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth.go
new file mode 100644
index 0000000..b438074
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth.go
@@ -0,0 +1,736 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2auth implements etcd authentication.
+package v2auth
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"path"
+	"reflect"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+	"golang.org/x/crypto/bcrypt"
+)
+
+const (
+	// StorePermsPrefix is the internal prefix of the storage layer dedicated to storing user data.
+	StorePermsPrefix = "/2"
+
+	// RootRoleName is the name of the ROOT role, with privileges to manage the cluster.
+	RootRoleName = "root"
+
+	// GuestRoleName is the name of the role that defines the privileges of an unauthenticated user.
+	GuestRoleName = "guest"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd/v3", "etcdserver/auth")
+)
+
+var rootRole = Role{
+	Role: RootRoleName,
+	Permissions: Permissions{
+		KV: RWPermission{
+			Read:  []string{"/*"},
+			Write: []string{"/*"},
+		},
+	},
+}
+
+var guestRole = Role{
+	Role: GuestRoleName,
+	Permissions: Permissions{
+		KV: RWPermission{
+			Read:  []string{"/*"},
+			Write: []string{"/*"},
+		},
+	},
+}
+
+type doer interface {
+	Do(context.Context, etcdserverpb.Request) (etcdserver.Response, error)
+}
+
+type Store interface {
+	AllUsers() ([]string, error)
+	GetUser(name string) (User, error)
+	CreateOrUpdateUser(user User) (out User, created bool, err error)
+	CreateUser(user User) (User, error)
+	DeleteUser(name string) error
+	UpdateUser(user User) (User, error)
+	AllRoles() ([]string, error)
+	GetRole(name string) (Role, error)
+	CreateRole(role Role) error
+	DeleteRole(name string) error
+	UpdateRole(role Role) (Role, error)
+	AuthEnabled() bool
+	EnableAuth() error
+	DisableAuth() error
+	PasswordStore
+}
+
+type PasswordStore interface {
+	CheckPassword(user User, password string) bool
+	HashPassword(password string) (string, error)
+}
+
+type store struct {
+	lg          *zap.Logger
+	server      doer
+	timeout     time.Duration
+	ensuredOnce bool
+
+	PasswordStore
+}
+
+type User struct {
+	User     string   `json:"user"`
+	Password string   `json:"password,omitempty"`
+	Roles    []string `json:"roles"`
+	Grant    []string `json:"grant,omitempty"`
+	Revoke   []string `json:"revoke,omitempty"`
+}
+
+type Role struct {
+	Role        string       `json:"role"`
+	Permissions Permissions  `json:"permissions"`
+	Grant       *Permissions `json:"grant,omitempty"`
+	Revoke      *Permissions `json:"revoke,omitempty"`
+}
+
+type Permissions struct {
+	KV RWPermission `json:"kv"`
+}
+
+func (p *Permissions) IsEmpty() bool {
+	return p == nil || (len(p.KV.Read) == 0 && len(p.KV.Write) == 0)
+}
+
+type RWPermission struct {
+	Read  []string `json:"read"`
+	Write []string `json:"write"`
+}
+
+type Error struct {
+	Status int
+	Errmsg string
+}
+
+func (ae Error) Error() string   { return ae.Errmsg }
+func (ae Error) HTTPStatus() int { return ae.Status }
+
+func authErr(hs int, s string, v ...interface{}) Error {
+	return Error{Status: hs, Errmsg: fmt.Sprintf("auth: "+s, v...)}
+}
+
+func NewStore(lg *zap.Logger, server doer, timeout time.Duration) Store {
+	s := &store{
+		lg:            lg,
+		server:        server,
+		timeout:       timeout,
+		PasswordStore: passwordStore{},
+	}
+	return s
+}
+
+// passwordStore implements PasswordStore using bcrypt to hash user passwords
+type passwordStore struct{}
+
+func (passwordStore) CheckPassword(user User, password string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password))
+	return err == nil
+}
+
+func (passwordStore) HashPassword(password string) (string, error) {
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	return string(hash), err
+}
+
+func (s *store) AllUsers() ([]string, error) {
+	resp, err := s.requestResource("/users/", false)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return []string{}, nil
+			}
+		}
+		return nil, err
+	}
+	var nodes []string
+	for _, n := range resp.Event.Node.Nodes {
+		_, user := path.Split(n.Key)
+		nodes = append(nodes, user)
+	}
+	sort.Strings(nodes)
+	return nodes, nil
+}
+
+func (s *store) GetUser(name string) (User, error) { return s.getUser(name, false) }
+
+// CreateOrUpdateUser should be only used for creating the new user or when you are not
+// sure if it is a create or update. (When only password is passed in, we are not sure
+// if it is a update or create)
+func (s *store) CreateOrUpdateUser(user User) (out User, created bool, err error) {
+	_, err = s.getUser(user.User, true)
+	if err == nil {
+		out, err = s.UpdateUser(user)
+		return out, false, err
+	}
+	u, err := s.CreateUser(user)
+	return u, true, err
+}
+
+func (s *store) CreateUser(user User) (User, error) {
+	// Attach root role to root user.
+	if user.User == "root" {
+		user = attachRootRole(user)
+	}
+	u, err := s.createUserInternal(user)
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("created a user", zap.String("user-name", user.User))
+		} else {
+			plog.Noticef("created user %s", user.User)
+		}
+	}
+	return u, err
+}
+
+func (s *store) createUserInternal(user User) (User, error) {
+	if user.Password == "" {
+		return user, authErr(http.StatusBadRequest, "Cannot create user %s with an empty password", user.User)
+	}
+	hash, err := s.HashPassword(user.Password)
+	if err != nil {
+		return user, err
+	}
+	user.Password = hash
+
+	_, err = s.createResource("/users/"+user.User, user)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeNodeExist {
+				return user, authErr(http.StatusConflict, "User %s already exists.", user.User)
+			}
+		}
+	}
+	return user, err
+}
+
+func (s *store) DeleteUser(name string) error {
+	if s.AuthEnabled() && name == "root" {
+		return authErr(http.StatusForbidden, "Cannot delete root user while auth is enabled.")
+	}
+	err := s.deleteResource("/users/" + name)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return authErr(http.StatusNotFound, "User %s does not exist", name)
+			}
+		}
+		return err
+	}
+	if s.lg != nil {
+		s.lg.Info("deleted a user", zap.String("user-name", name))
+	} else {
+		plog.Noticef("deleted user %s", name)
+	}
+	return nil
+}
+
+func (s *store) UpdateUser(user User) (User, error) {
+	old, err := s.getUser(user.User, true)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return user, authErr(http.StatusNotFound, "User %s doesn't exist.", user.User)
+			}
+		}
+		return old, err
+	}
+
+	newUser, err := old.merge(s.lg, user, s.PasswordStore)
+	if err != nil {
+		return old, err
+	}
+	if reflect.DeepEqual(old, newUser) {
+		return old, authErr(http.StatusBadRequest, "User not updated. Use grant/revoke/password to update the user.")
+	}
+	_, err = s.updateResource("/users/"+user.User, newUser)
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("updated a user", zap.String("user-name", user.User))
+		} else {
+			plog.Noticef("updated user %s", user.User)
+		}
+	}
+	return newUser, err
+}
+
+func (s *store) AllRoles() ([]string, error) {
+	nodes := []string{RootRoleName}
+	resp, err := s.requestResource("/roles/", false)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return nodes, nil
+			}
+		}
+		return nil, err
+	}
+	for _, n := range resp.Event.Node.Nodes {
+		_, role := path.Split(n.Key)
+		nodes = append(nodes, role)
+	}
+	sort.Strings(nodes)
+	return nodes, nil
+}
+
+func (s *store) GetRole(name string) (Role, error) { return s.getRole(name, false) }
+
+func (s *store) CreateRole(role Role) error {
+	if role.Role == RootRoleName {
+		return authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", role.Role)
+	}
+	_, err := s.createResource("/roles/"+role.Role, role)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeNodeExist {
+				return authErr(http.StatusConflict, "Role %s already exists.", role.Role)
+			}
+		}
+	}
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("created a new role", zap.String("role-name", role.Role))
+		} else {
+			plog.Noticef("created new role %s", role.Role)
+		}
+	}
+	return err
+}
+
+func (s *store) DeleteRole(name string) error {
+	if name == RootRoleName {
+		return authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", name)
+	}
+	err := s.deleteResource("/roles/" + name)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return authErr(http.StatusNotFound, "Role %s doesn't exist.", name)
+			}
+		}
+	}
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("delete a new role", zap.String("role-name", name))
+		} else {
+			plog.Noticef("deleted role %s", name)
+		}
+	}
+	return err
+}
+
+func (s *store) UpdateRole(role Role) (Role, error) {
+	if role.Role == RootRoleName {
+		return Role{}, authErr(http.StatusForbidden, "Cannot modify role %s: is root role.", role.Role)
+	}
+	old, err := s.getRole(role.Role, true)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return role, authErr(http.StatusNotFound, "Role %s doesn't exist.", role.Role)
+			}
+		}
+		return old, err
+	}
+	newRole, err := old.merge(s.lg, role)
+	if err != nil {
+		return old, err
+	}
+	if reflect.DeepEqual(old, newRole) {
+		return old, authErr(http.StatusBadRequest, "Role not updated. Use grant/revoke to update the role.")
+	}
+	_, err = s.updateResource("/roles/"+role.Role, newRole)
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("updated a new role", zap.String("role-name", role.Role))
+		} else {
+			plog.Noticef("updated role %s", role.Role)
+		}
+	}
+	return newRole, err
+}
+
+func (s *store) AuthEnabled() bool {
+	return s.detectAuth()
+}
+
+func (s *store) EnableAuth() error {
+	if s.AuthEnabled() {
+		return authErr(http.StatusConflict, "already enabled")
+	}
+
+	if _, err := s.getUser("root", true); err != nil {
+		return authErr(http.StatusConflict, "No root user available, please create one")
+	}
+	if _, err := s.getRole(GuestRoleName, true); err != nil {
+		if s.lg != nil {
+			s.lg.Info(
+				"no guest role access found; creating default",
+				zap.String("role-name", GuestRoleName),
+			)
+		} else {
+			plog.Printf("no guest role access found, creating default")
+		}
+		if err := s.CreateRole(guestRole); err != nil {
+			if s.lg != nil {
+				s.lg.Warn(
+					"failed to create a guest role; aborting auth enable",
+					zap.String("role-name", GuestRoleName),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("error creating guest role. aborting auth enable.")
+			}
+			return err
+		}
+	}
+
+	if err := s.enableAuth(); err != nil {
+		if s.lg != nil {
+			s.lg.Warn("failed to enable auth", zap.Error(err))
+		} else {
+			plog.Errorf("error enabling auth (%v)", err)
+		}
+		return err
+	}
+
+	if s.lg != nil {
+		s.lg.Info("enabled auth")
+	} else {
+		plog.Noticef("auth: enabled auth")
+	}
+	return nil
+}
+
+func (s *store) DisableAuth() error {
+	if !s.AuthEnabled() {
+		return authErr(http.StatusConflict, "already disabled")
+	}
+
+	err := s.disableAuth()
+	if err == nil {
+		if s.lg != nil {
+			s.lg.Info("disabled auth")
+		} else {
+			plog.Noticef("auth: disabled auth")
+		}
+	} else {
+		if s.lg != nil {
+			s.lg.Warn("failed to disable auth", zap.Error(err))
+		} else {
+			plog.Errorf("error disabling auth (%v)", err)
+		}
+	}
+	return err
+}
+
+// merge applies the properties of the passed-in User to the User on which it
+// is called and returns a new User with these modifications applied. Think of
+// all Users as immutable sets of data. Merge allows you to perform the set
+// operations (desired grants and revokes) atomically
+func (ou User) merge(lg *zap.Logger, nu User, s PasswordStore) (User, error) {
+	var out User
+	if ou.User != nu.User {
+		return out, authErr(http.StatusConflict, "Merging user data with conflicting usernames: %s %s", ou.User, nu.User)
+	}
+	out.User = ou.User
+	if nu.Password != "" {
+		hash, err := s.HashPassword(nu.Password)
+		if err != nil {
+			return ou, err
+		}
+		out.Password = hash
+	} else {
+		out.Password = ou.Password
+	}
+	currentRoles := types.NewUnsafeSet(ou.Roles...)
+	for _, g := range nu.Grant {
+		if currentRoles.Contains(g) {
+			if lg != nil {
+				lg.Warn(
+					"attempted to grant a duplicate role for a user",
+					zap.String("user-name", nu.User),
+					zap.String("role-name", g),
+				)
+			} else {
+				plog.Noticef("granting duplicate role %s for user %s", g, nu.User)
+			}
+			return User{}, authErr(http.StatusConflict, fmt.Sprintf("Granting duplicate role %s for user %s", g, nu.User))
+		}
+		currentRoles.Add(g)
+	}
+	for _, r := range nu.Revoke {
+		if !currentRoles.Contains(r) {
+			if lg != nil {
+				lg.Warn(
+					"attempted to revoke a ungranted role for a user",
+					zap.String("user-name", nu.User),
+					zap.String("role-name", r),
+				)
+			} else {
+				plog.Noticef("revoking ungranted role %s for user %s", r, nu.User)
+			}
+			return User{}, authErr(http.StatusConflict, fmt.Sprintf("Revoking ungranted role %s for user %s", r, nu.User))
+		}
+		currentRoles.Remove(r)
+	}
+	out.Roles = currentRoles.Values()
+	sort.Strings(out.Roles)
+	return out, nil
+}
+
+// merge for a role works the same as User above -- atomic Role application to
+// each of the substructures.
+func (r Role) merge(lg *zap.Logger, n Role) (Role, error) {
+	var out Role
+	var err error
+	if r.Role != n.Role {
+		return out, authErr(http.StatusConflict, "Merging role with conflicting names: %s %s", r.Role, n.Role)
+	}
+	out.Role = r.Role
+	out.Permissions, err = r.Permissions.Grant(n.Grant)
+	if err != nil {
+		return out, err
+	}
+	out.Permissions, err = out.Permissions.Revoke(lg, n.Revoke)
+	return out, err
+}
+
+func (r Role) HasKeyAccess(key string, write bool) bool {
+	if r.Role == RootRoleName {
+		return true
+	}
+	return r.Permissions.KV.HasAccess(key, write)
+}
+
+func (r Role) HasRecursiveAccess(key string, write bool) bool {
+	if r.Role == RootRoleName {
+		return true
+	}
+	return r.Permissions.KV.HasRecursiveAccess(key, write)
+}
+
+// Grant adds a set of permissions to the permission object on which it is called,
+// returning a new permission object.
+func (p Permissions) Grant(n *Permissions) (Permissions, error) {
+	var out Permissions
+	var err error
+	if n == nil {
+		return p, nil
+	}
+	out.KV, err = p.KV.Grant(n.KV)
+	return out, err
+}
+
+// Revoke removes a set of permissions to the permission object on which it is called,
+// returning a new permission object.
+func (p Permissions) Revoke(lg *zap.Logger, n *Permissions) (Permissions, error) {
+	var out Permissions
+	var err error
+	if n == nil {
+		return p, nil
+	}
+	out.KV, err = p.KV.Revoke(lg, n.KV)
+	return out, err
+}
+
+// Grant adds a set of permissions to the permission object on which it is called,
+// returning a new permission object.
+func (rw RWPermission) Grant(n RWPermission) (RWPermission, error) {
+	var out RWPermission
+	currentRead := types.NewUnsafeSet(rw.Read...)
+	for _, r := range n.Read {
+		if currentRead.Contains(r) {
+			return out, authErr(http.StatusConflict, "Granting duplicate read permission %s", r)
+		}
+		currentRead.Add(r)
+	}
+	currentWrite := types.NewUnsafeSet(rw.Write...)
+	for _, w := range n.Write {
+		if currentWrite.Contains(w) {
+			return out, authErr(http.StatusConflict, "Granting duplicate write permission %s", w)
+		}
+		currentWrite.Add(w)
+	}
+	out.Read = currentRead.Values()
+	out.Write = currentWrite.Values()
+	sort.Strings(out.Read)
+	sort.Strings(out.Write)
+	return out, nil
+}
+
+// Revoke removes a set of permissions to the permission object on which it is called,
+// returning a new permission object.
+func (rw RWPermission) Revoke(lg *zap.Logger, n RWPermission) (RWPermission, error) {
+	var out RWPermission
+	currentRead := types.NewUnsafeSet(rw.Read...)
+	for _, r := range n.Read {
+		if !currentRead.Contains(r) {
+			if lg != nil {
+				lg.Info(
+					"revoking ungranted read permission",
+					zap.String("read-permission", r),
+				)
+			} else {
+				plog.Noticef("revoking ungranted read permission %s", r)
+			}
+			continue
+		}
+		currentRead.Remove(r)
+	}
+	currentWrite := types.NewUnsafeSet(rw.Write...)
+	for _, w := range n.Write {
+		if !currentWrite.Contains(w) {
+			if lg != nil {
+				lg.Info(
+					"revoking ungranted write permission",
+					zap.String("write-permission", w),
+				)
+			} else {
+				plog.Noticef("revoking ungranted write permission %s", w)
+			}
+			continue
+		}
+		currentWrite.Remove(w)
+	}
+	out.Read = currentRead.Values()
+	out.Write = currentWrite.Values()
+	sort.Strings(out.Read)
+	sort.Strings(out.Write)
+	return out, nil
+}
+
+func (rw RWPermission) HasAccess(key string, write bool) bool {
+	var list []string
+	if write {
+		list = rw.Write
+	} else {
+		list = rw.Read
+	}
+	for _, pat := range list {
+		match, err := simpleMatch(pat, key)
+		if err == nil && match {
+			return true
+		}
+	}
+	return false
+}
+
+func (rw RWPermission) HasRecursiveAccess(key string, write bool) bool {
+	list := rw.Read
+	if write {
+		list = rw.Write
+	}
+	for _, pat := range list {
+		match, err := prefixMatch(pat, key)
+		if err == nil && match {
+			return true
+		}
+	}
+	return false
+}
+
+func simpleMatch(pattern string, key string) (match bool, err error) {
+	if pattern[len(pattern)-1] == '*' {
+		return strings.HasPrefix(key, pattern[:len(pattern)-1]), nil
+	}
+	return key == pattern, nil
+}
+
+func prefixMatch(pattern string, key string) (match bool, err error) {
+	if pattern[len(pattern)-1] != '*' {
+		return false, nil
+	}
+	return strings.HasPrefix(key, pattern[:len(pattern)-1]), nil
+}
+
+func attachRootRole(u User) User {
+	inRoles := false
+	for _, r := range u.Roles {
+		if r == RootRoleName {
+			inRoles = true
+			break
+		}
+	}
+	if !inRoles {
+		u.Roles = append(u.Roles, RootRoleName)
+	}
+	return u
+}
+
+func (s *store) getUser(name string, quorum bool) (User, error) {
+	resp, err := s.requestResource("/users/"+name, quorum)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return User{}, authErr(http.StatusNotFound, "User %s does not exist.", name)
+			}
+		}
+		return User{}, err
+	}
+	var u User
+	err = json.Unmarshal([]byte(*resp.Event.Node.Value), &u)
+	if err != nil {
+		return u, err
+	}
+	// Attach root role to root user.
+	if u.User == "root" {
+		u = attachRootRole(u)
+	}
+	return u, nil
+}
+
+func (s *store) getRole(name string, quorum bool) (Role, error) {
+	if name == RootRoleName {
+		return rootRole, nil
+	}
+	resp, err := s.requestResource("/roles/"+name, quorum)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return Role{}, authErr(http.StatusNotFound, "Role %s does not exist.", name)
+			}
+		}
+		return Role{}, err
+	}
+	var r Role
+	err = json.Unmarshal([]byte(*resp.Event.Node.Value), &r)
+	return r, err
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth_requests.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth_requests.go
new file mode 100644
index 0000000..d6574ec
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2auth/auth_requests.go
@@ -0,0 +1,189 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2auth
+
+import (
+	"context"
+	"encoding/json"
+	"path"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"go.uber.org/zap"
+)
+
+func (s *store) ensureAuthDirectories() error {
+	if s.ensuredOnce {
+		return nil
+	}
+	for _, res := range []string{StorePermsPrefix, StorePermsPrefix + "/users/", StorePermsPrefix + "/roles/"} {
+		ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
+		pe := false
+		rr := etcdserverpb.Request{
+			Method:    "PUT",
+			Path:      res,
+			Dir:       true,
+			PrevExist: &pe,
+		}
+		_, err := s.server.Do(ctx, rr)
+		cancel()
+		if err != nil {
+			if e, ok := err.(*v2error.Error); ok {
+				if e.ErrorCode == v2error.EcodeNodeExist {
+					continue
+				}
+			}
+			if s.lg != nil {
+				s.lg.Warn(
+					"failed to create auth directories",
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("failed to create auth directories in the store (%v)", err)
+			}
+			return err
+		}
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
+	defer cancel()
+	pe := false
+	rr := etcdserverpb.Request{
+		Method:    "PUT",
+		Path:      StorePermsPrefix + "/enabled",
+		Val:       "false",
+		PrevExist: &pe,
+	}
+	_, err := s.server.Do(ctx, rr)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeNodeExist {
+				s.ensuredOnce = true
+				return nil
+			}
+		}
+		return err
+	}
+	s.ensuredOnce = true
+	return nil
+}
+
+func (s *store) enableAuth() error {
+	_, err := s.updateResource("/enabled", true)
+	return err
+}
+func (s *store) disableAuth() error {
+	_, err := s.updateResource("/enabled", false)
+	return err
+}
+
+func (s *store) detectAuth() bool {
+	if s.server == nil {
+		return false
+	}
+	value, err := s.requestResource("/enabled", false)
+	if err != nil {
+		if e, ok := err.(*v2error.Error); ok {
+			if e.ErrorCode == v2error.EcodeKeyNotFound {
+				return false
+			}
+		}
+		if s.lg != nil {
+			s.lg.Warn(
+				"failed to detect auth settings",
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("failed to detect auth settings (%s)", err)
+		}
+		return false
+	}
+
+	var u bool
+	err = json.Unmarshal([]byte(*value.Event.Node.Value), &u)
+	if err != nil {
+		if s.lg != nil {
+			s.lg.Warn(
+				"internal bookkeeping value for enabled isn't valid JSON",
+				zap.Error(err),
+			)
+		} else {
+			plog.Errorf("internal bookkeeping value for enabled isn't valid JSON (%v)", err)
+		}
+		return false
+	}
+	return u
+}
+
+func (s *store) requestResource(res string, quorum bool) (etcdserver.Response, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
+	defer cancel()
+	p := path.Join(StorePermsPrefix, res)
+	method := "GET"
+	if quorum {
+		method = "QGET"
+	}
+	rr := etcdserverpb.Request{
+		Method: method,
+		Path:   p,
+		Dir:    false, // TODO: always false?
+	}
+	return s.server.Do(ctx, rr)
+}
+
+func (s *store) updateResource(res string, value interface{}) (etcdserver.Response, error) {
+	return s.setResource(res, value, true)
+}
+func (s *store) createResource(res string, value interface{}) (etcdserver.Response, error) {
+	return s.setResource(res, value, false)
+}
+func (s *store) setResource(res string, value interface{}, prevexist bool) (etcdserver.Response, error) {
+	err := s.ensureAuthDirectories()
+	if err != nil {
+		return etcdserver.Response{}, err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
+	defer cancel()
+	data, err := json.Marshal(value)
+	if err != nil {
+		return etcdserver.Response{}, err
+	}
+	p := path.Join(StorePermsPrefix, res)
+	rr := etcdserverpb.Request{
+		Method:    "PUT",
+		Path:      p,
+		Val:       string(data),
+		PrevExist: &prevexist,
+	}
+	return s.server.Do(ctx, rr)
+}
+
+func (s *store) deleteResource(res string) error {
+	err := s.ensureAuthDirectories()
+	if err != nil {
+		return err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
+	defer cancel()
+	pex := true
+	p := path.Join(StorePermsPrefix, res)
+	_, err = s.server.Do(ctx, etcdserverpb.Request{
+		Method:    "DELETE",
+		Path:      p,
+		PrevExist: &pex,
+	})
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2discovery/discovery.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2discovery/discovery.go
new file mode 100644
index 0000000..cf770b3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2discovery/discovery.go
@@ -0,0 +1,440 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2discovery provides an implementation of the cluster discovery that
+// is used by etcd with v2 client.
+package v2discovery
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math"
+	"net/http"
+	"net/url"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/client"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/pkg/capnslog"
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "discovery")
+
+	ErrInvalidURL           = errors.New("discovery: invalid URL")
+	ErrBadSizeKey           = errors.New("discovery: size key is bad")
+	ErrSizeNotFound         = errors.New("discovery: size key not found")
+	ErrTokenNotFound        = errors.New("discovery: token not found")
+	ErrDuplicateID          = errors.New("discovery: found duplicate id")
+	ErrDuplicateName        = errors.New("discovery: found duplicate name")
+	ErrFullCluster          = errors.New("discovery: cluster is full")
+	ErrTooManyRetries       = errors.New("discovery: too many retries")
+	ErrBadDiscoveryEndpoint = errors.New("discovery: bad discovery endpoint")
+)
+
+var (
+	// Number of retries discovery will attempt before giving up and erroring out.
+	nRetries             = uint(math.MaxUint32)
+	maxExpoentialRetries = uint(8)
+)
+
+// JoinCluster will connect to the discovery service at the given url, and
+// register the server represented by the given id and config to the cluster
+func JoinCluster(lg *zap.Logger, durl, dproxyurl string, id types.ID, config string) (string, error) {
+	d, err := newDiscovery(lg, durl, dproxyurl, id)
+	if err != nil {
+		return "", err
+	}
+	return d.joinCluster(config)
+}
+
+// GetCluster will connect to the discovery service at the given url and
+// retrieve a string describing the cluster
+func GetCluster(lg *zap.Logger, durl, dproxyurl string) (string, error) {
+	d, err := newDiscovery(lg, durl, dproxyurl, 0)
+	if err != nil {
+		return "", err
+	}
+	return d.getCluster()
+}
+
+type discovery struct {
+	lg      *zap.Logger
+	cluster string
+	id      types.ID
+	c       client.KeysAPI
+	retries uint
+	url     *url.URL
+
+	clock clockwork.Clock
+}
+
+// newProxyFunc builds a proxy function from the given string, which should
+// represent a URL that can be used as a proxy. It performs basic
+// sanitization of the URL and returns any error encountered.
+func newProxyFunc(lg *zap.Logger, proxy string) (func(*http.Request) (*url.URL, error), error) {
+	if proxy == "" {
+		return nil, nil
+	}
+	// Do a small amount of URL sanitization to help the user
+	// Derived from net/http.ProxyFromEnvironment
+	proxyURL, err := url.Parse(proxy)
+	if err != nil || !strings.HasPrefix(proxyURL.Scheme, "http") {
+		// proxy was bogus. Try prepending "http://" to it and
+		// see if that parses correctly. If not, we ignore the
+		// error and complain about the original one
+		var err2 error
+		proxyURL, err2 = url.Parse("http://" + proxy)
+		if err2 == nil {
+			err = nil
+		}
+	}
+	if err != nil {
+		return nil, fmt.Errorf("invalid proxy address %q: %v", proxy, err)
+	}
+
+	if lg != nil {
+		lg.Info("running proxy with discovery", zap.String("proxy-url", proxyURL.String()))
+	} else {
+		plog.Infof("using proxy %q", proxyURL.String())
+	}
+	return http.ProxyURL(proxyURL), nil
+}
+
+func newDiscovery(lg *zap.Logger, durl, dproxyurl string, id types.ID) (*discovery, error) {
+	u, err := url.Parse(durl)
+	if err != nil {
+		return nil, err
+	}
+	token := u.Path
+	u.Path = ""
+	pf, err := newProxyFunc(lg, dproxyurl)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: add ResponseHeaderTimeout back when watch on discovery service writes header early
+	tr, err := transport.NewTransport(transport.TLSInfo{}, 30*time.Second)
+	if err != nil {
+		return nil, err
+	}
+	tr.Proxy = pf
+	cfg := client.Config{
+		Transport: tr,
+		Endpoints: []string{u.String()},
+	}
+	c, err := client.New(cfg)
+	if err != nil {
+		return nil, err
+	}
+	dc := client.NewKeysAPIWithPrefix(c, "")
+	return &discovery{
+		lg:      lg,
+		cluster: token,
+		c:       dc,
+		id:      id,
+		url:     u,
+		clock:   clockwork.NewRealClock(),
+	}, nil
+}
+
+func (d *discovery) joinCluster(config string) (string, error) {
+	// fast path: if the cluster is full, return the error
+	// do not need to register to the cluster in this case.
+	if _, _, _, err := d.checkCluster(); err != nil {
+		return "", err
+	}
+
+	if err := d.createSelf(config); err != nil {
+		// Fails, even on a timeout, if createSelf times out.
+		// TODO(barakmich): Retrying the same node might want to succeed here
+		// (ie, createSelf should be idempotent for discovery).
+		return "", err
+	}
+
+	nodes, size, index, err := d.checkCluster()
+	if err != nil {
+		return "", err
+	}
+
+	all, err := d.waitNodes(nodes, size, index)
+	if err != nil {
+		return "", err
+	}
+
+	return nodesToCluster(all, size)
+}
+
+func (d *discovery) getCluster() (string, error) {
+	nodes, size, index, err := d.checkCluster()
+	if err != nil {
+		if err == ErrFullCluster {
+			return nodesToCluster(nodes, size)
+		}
+		return "", err
+	}
+
+	all, err := d.waitNodes(nodes, size, index)
+	if err != nil {
+		return "", err
+	}
+	return nodesToCluster(all, size)
+}
+
+func (d *discovery) createSelf(contents string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+	resp, err := d.c.Create(ctx, d.selfKey(), contents)
+	cancel()
+	if err != nil {
+		if eerr, ok := err.(client.Error); ok && eerr.Code == client.ErrorCodeNodeExist {
+			return ErrDuplicateID
+		}
+		return err
+	}
+
+	// ensure self appears on the server we connected to
+	w := d.c.Watcher(d.selfKey(), &client.WatcherOptions{AfterIndex: resp.Node.CreatedIndex - 1})
+	_, err = w.Next(context.Background())
+	return err
+}
+
+func (d *discovery) checkCluster() ([]*client.Node, int, uint64, error) {
+	configKey := path.Join("/", d.cluster, "_config")
+	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+	// find cluster size
+	resp, err := d.c.Get(ctx, path.Join(configKey, "size"), nil)
+	cancel()
+	if err != nil {
+		if eerr, ok := err.(*client.Error); ok && eerr.Code == client.ErrorCodeKeyNotFound {
+			return nil, 0, 0, ErrSizeNotFound
+		}
+		if err == client.ErrInvalidJSON {
+			return nil, 0, 0, ErrBadDiscoveryEndpoint
+		}
+		if ce, ok := err.(*client.ClusterError); ok {
+			if d.lg != nil {
+				d.lg.Warn(
+					"failed to get from discovery server",
+					zap.String("discovery-url", d.url.String()),
+					zap.String("path", path.Join(configKey, "size")),
+					zap.Error(err),
+					zap.String("err-detail", ce.Detail()),
+				)
+			} else {
+				plog.Error(ce.Detail())
+			}
+			return d.checkClusterRetry()
+		}
+		return nil, 0, 0, err
+	}
+	size, err := strconv.Atoi(resp.Node.Value)
+	if err != nil {
+		return nil, 0, 0, ErrBadSizeKey
+	}
+
+	ctx, cancel = context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+	resp, err = d.c.Get(ctx, d.cluster, nil)
+	cancel()
+	if err != nil {
+		if ce, ok := err.(*client.ClusterError); ok {
+			if d.lg != nil {
+				d.lg.Warn(
+					"failed to get from discovery server",
+					zap.String("discovery-url", d.url.String()),
+					zap.String("path", d.cluster),
+					zap.Error(err),
+					zap.String("err-detail", ce.Detail()),
+				)
+			} else {
+				plog.Error(ce.Detail())
+			}
+			return d.checkClusterRetry()
+		}
+		return nil, 0, 0, err
+	}
+	var nodes []*client.Node
+	// append non-config keys to nodes
+	for _, n := range resp.Node.Nodes {
+		if path.Base(n.Key) != path.Base(configKey) {
+			nodes = append(nodes, n)
+		}
+	}
+
+	snodes := sortableNodes{nodes}
+	sort.Sort(snodes)
+
+	// find self position
+	for i := range nodes {
+		if path.Base(nodes[i].Key) == path.Base(d.selfKey()) {
+			break
+		}
+		if i >= size-1 {
+			return nodes[:size], size, resp.Index, ErrFullCluster
+		}
+	}
+	return nodes, size, resp.Index, nil
+}
+
+func (d *discovery) logAndBackoffForRetry(step string) {
+	d.retries++
+	// logAndBackoffForRetry stops exponential backoff when the retries are more than maxExpoentialRetries and is set to a constant backoff afterward.
+	retries := d.retries
+	if retries > maxExpoentialRetries {
+		retries = maxExpoentialRetries
+	}
+	retryTimeInSecond := time.Duration(0x1<<retries) * time.Second
+	if d.lg != nil {
+		d.lg.Info(
+			"retry connecting to discovery service",
+			zap.String("url", d.url.String()),
+			zap.String("reason", step),
+			zap.Duration("backoff", retryTimeInSecond),
+		)
+	} else {
+		plog.Infof("%s: error connecting to %s, retrying in %s", step, d.url, retryTimeInSecond)
+	}
+	d.clock.Sleep(retryTimeInSecond)
+}
+
+func (d *discovery) checkClusterRetry() ([]*client.Node, int, uint64, error) {
+	if d.retries < nRetries {
+		d.logAndBackoffForRetry("cluster status check")
+		return d.checkCluster()
+	}
+	return nil, 0, 0, ErrTooManyRetries
+}
+
+func (d *discovery) waitNodesRetry() ([]*client.Node, error) {
+	if d.retries < nRetries {
+		d.logAndBackoffForRetry("waiting for other nodes")
+		nodes, n, index, err := d.checkCluster()
+		if err != nil {
+			return nil, err
+		}
+		return d.waitNodes(nodes, n, index)
+	}
+	return nil, ErrTooManyRetries
+}
+
+func (d *discovery) waitNodes(nodes []*client.Node, size int, index uint64) ([]*client.Node, error) {
+	if len(nodes) > size {
+		nodes = nodes[:size]
+	}
+	// watch from the next index
+	w := d.c.Watcher(d.cluster, &client.WatcherOptions{AfterIndex: index, Recursive: true})
+	all := make([]*client.Node, len(nodes))
+	copy(all, nodes)
+	for _, n := range all {
+		if path.Base(n.Key) == path.Base(d.selfKey()) {
+			if d.lg != nil {
+				d.lg.Info(
+					"found self from discovery server",
+					zap.String("discovery-url", d.url.String()),
+					zap.String("self", path.Base(d.selfKey())),
+				)
+			} else {
+				plog.Noticef("found self %s in the cluster", path.Base(d.selfKey()))
+			}
+		} else {
+			if d.lg != nil {
+				d.lg.Info(
+					"found peer from discovery server",
+					zap.String("discovery-url", d.url.String()),
+					zap.String("peer", path.Base(n.Key)),
+				)
+			} else {
+				plog.Noticef("found peer %s in the cluster", path.Base(n.Key))
+			}
+		}
+	}
+
+	// wait for others
+	for len(all) < size {
+		if d.lg != nil {
+			d.lg.Info(
+				"found peers from discovery server; waiting for more",
+				zap.String("discovery-url", d.url.String()),
+				zap.Int("found-peers", len(all)),
+				zap.Int("needed-peers", size-len(all)),
+			)
+		} else {
+			plog.Noticef("found %d peer(s), waiting for %d more", len(all), size-len(all))
+		}
+		resp, err := w.Next(context.Background())
+		if err != nil {
+			if ce, ok := err.(*client.ClusterError); ok {
+				plog.Error(ce.Detail())
+				return d.waitNodesRetry()
+			}
+			return nil, err
+		}
+		if d.lg != nil {
+			d.lg.Info(
+				"found peer from discovery server",
+				zap.String("discovery-url", d.url.String()),
+				zap.String("peer", path.Base(resp.Node.Key)),
+			)
+		} else {
+			plog.Noticef("found peer %s in the cluster", path.Base(resp.Node.Key))
+		}
+		all = append(all, resp.Node)
+	}
+	if d.lg != nil {
+		d.lg.Info(
+			"found all needed peers from discovery server",
+			zap.String("discovery-url", d.url.String()),
+			zap.Int("found-peers", len(all)),
+		)
+	} else {
+		plog.Noticef("found %d needed peer(s)", len(all))
+	}
+	return all, nil
+}
+
+func (d *discovery) selfKey() string {
+	return path.Join("/", d.cluster, d.id.String())
+}
+
+func nodesToCluster(ns []*client.Node, size int) (string, error) {
+	s := make([]string, len(ns))
+	for i, n := range ns {
+		s[i] = n.Value
+	}
+	us := strings.Join(s, ",")
+	m, err := types.NewURLsMap(us)
+	if err != nil {
+		return us, ErrInvalidURL
+	}
+	if m.Len() != size {
+		return us, ErrDuplicateName
+	}
+	return us, nil
+}
+
+type sortableNodes struct{ Nodes []*client.Node }
+
+func (ns sortableNodes) Len() int { return len(ns.Nodes) }
+func (ns sortableNodes) Less(i, j int) bool {
+	return ns.Nodes[i].CreatedIndex < ns.Nodes[j].CreatedIndex
+}
+func (ns sortableNodes) Swap(i, j int) { ns.Nodes[i], ns.Nodes[j] = ns.Nodes[j], ns.Nodes[i] }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2error/error.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2error/error.go
new file mode 100644
index 0000000..1244290
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2error/error.go
@@ -0,0 +1,164 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2error describes errors in etcd project. When any change happens,
+// Documentation/v2/errorcode.md needs to be updated correspondingly.
+// To be deprecated in favor of v3 APIs.
+package v2error
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+var errors = map[int]string{
+	// command related errors
+	EcodeKeyNotFound:      "Key not found",
+	EcodeTestFailed:       "Compare failed", //test and set
+	EcodeNotFile:          "Not a file",
+	ecodeNoMorePeer:       "Reached the max number of peers in the cluster",
+	EcodeNotDir:           "Not a directory",
+	EcodeNodeExist:        "Key already exists", // create
+	ecodeKeyIsPreserved:   "The prefix of given key is a keyword in etcd",
+	EcodeRootROnly:        "Root is read only",
+	EcodeDirNotEmpty:      "Directory not empty",
+	ecodeExistingPeerAddr: "Peer address has existed",
+	EcodeUnauthorized:     "The request requires user authentication",
+
+	// Post form related errors
+	ecodeValueRequired:        "Value is Required in POST form",
+	EcodePrevValueRequired:    "PrevValue is Required in POST form",
+	EcodeTTLNaN:               "The given TTL in POST form is not a number",
+	EcodeIndexNaN:             "The given index in POST form is not a number",
+	ecodeValueOrTTLRequired:   "Value or TTL is required in POST form",
+	ecodeTimeoutNaN:           "The given timeout in POST form is not a number",
+	ecodeNameRequired:         "Name is required in POST form",
+	ecodeIndexOrValueRequired: "Index or value is required",
+	ecodeIndexValueMutex:      "Index and value cannot both be specified",
+	EcodeInvalidField:         "Invalid field",
+	EcodeInvalidForm:          "Invalid POST form",
+	EcodeRefreshValue:         "Value provided on refresh",
+	EcodeRefreshTTLRequired:   "A TTL must be provided on refresh",
+
+	// raft related errors
+	EcodeRaftInternal: "Raft Internal Error",
+	EcodeLeaderElect:  "During Leader Election",
+
+	// etcd related errors
+	EcodeWatcherCleared:     "watcher is cleared due to etcd recovery",
+	EcodeEventIndexCleared:  "The event in requested index is outdated and cleared",
+	ecodeStandbyInternal:    "Standby Internal Error",
+	ecodeInvalidActiveSize:  "Invalid active size",
+	ecodeInvalidRemoveDelay: "Standby remove delay",
+
+	// client related errors
+	ecodeClientInternal: "Client Internal Error",
+}
+
+var errorStatus = map[int]int{
+	EcodeKeyNotFound:  http.StatusNotFound,
+	EcodeNotFile:      http.StatusForbidden,
+	EcodeDirNotEmpty:  http.StatusForbidden,
+	EcodeUnauthorized: http.StatusUnauthorized,
+	EcodeTestFailed:   http.StatusPreconditionFailed,
+	EcodeNodeExist:    http.StatusPreconditionFailed,
+	EcodeRaftInternal: http.StatusInternalServerError,
+	EcodeLeaderElect:  http.StatusInternalServerError,
+}
+
+const (
+	EcodeKeyNotFound      = 100
+	EcodeTestFailed       = 101
+	EcodeNotFile          = 102
+	ecodeNoMorePeer       = 103
+	EcodeNotDir           = 104
+	EcodeNodeExist        = 105
+	ecodeKeyIsPreserved   = 106
+	EcodeRootROnly        = 107
+	EcodeDirNotEmpty      = 108
+	ecodeExistingPeerAddr = 109
+	EcodeUnauthorized     = 110
+
+	ecodeValueRequired        = 200
+	EcodePrevValueRequired    = 201
+	EcodeTTLNaN               = 202
+	EcodeIndexNaN             = 203
+	ecodeValueOrTTLRequired   = 204
+	ecodeTimeoutNaN           = 205
+	ecodeNameRequired         = 206
+	ecodeIndexOrValueRequired = 207
+	ecodeIndexValueMutex      = 208
+	EcodeInvalidField         = 209
+	EcodeInvalidForm          = 210
+	EcodeRefreshValue         = 211
+	EcodeRefreshTTLRequired   = 212
+
+	EcodeRaftInternal = 300
+	EcodeLeaderElect  = 301
+
+	EcodeWatcherCleared     = 400
+	EcodeEventIndexCleared  = 401
+	ecodeStandbyInternal    = 402
+	ecodeInvalidActiveSize  = 403
+	ecodeInvalidRemoveDelay = 404
+
+	ecodeClientInternal = 500
+)
+
+type Error struct {
+	ErrorCode int    `json:"errorCode"`
+	Message   string `json:"message"`
+	Cause     string `json:"cause,omitempty"`
+	Index     uint64 `json:"index"`
+}
+
+func NewRequestError(errorCode int, cause string) *Error {
+	return NewError(errorCode, cause, 0)
+}
+
+func NewError(errorCode int, cause string, index uint64) *Error {
+	return &Error{
+		ErrorCode: errorCode,
+		Message:   errors[errorCode],
+		Cause:     cause,
+		Index:     index,
+	}
+}
+
+// Error is for the error interface
+func (e Error) Error() string {
+	return e.Message + " (" + e.Cause + ")"
+}
+
+func (e Error) toJsonString() string {
+	b, _ := json.Marshal(e)
+	return string(b)
+}
+
+func (e Error) StatusCode() int {
+	status, ok := errorStatus[e.ErrorCode]
+	if !ok {
+		status = http.StatusBadRequest
+	}
+	return status
+}
+
+func (e Error) WriteTo(w http.ResponseWriter) error {
+	w.Header().Add("X-Etcd-Index", fmt.Sprint(e.Index))
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(e.StatusCode())
+	_, err := w.Write([]byte(e.toJsonString() + "\n"))
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/capability.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/capability.go
new file mode 100644
index 0000000..ed6c456
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/capability.go
@@ -0,0 +1,40 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"fmt"
+	"net/http"
+
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+)
+
+func authCapabilityHandler(fn func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !api.IsCapabilityEnabled(api.AuthCapability) {
+			notCapable(w, r, api.AuthCapability)
+			return
+		}
+		fn(w, r)
+	}
+}
+
+func notCapable(w http.ResponseWriter, r *http.Request, c api.Capability) {
+	herr := httptypes.NewHTTPError(http.StatusInternalServerError, fmt.Sprintf("Not capable of accessing %s feature during rolling upgrades.", c))
+	if err := herr.WriteTo(w); err != nil {
+		plog.Debugf("error writing HTTPError (%v) to %s", err, r.RemoteAddr)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client.go
new file mode 100644
index 0000000..1d1e592
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client.go
@@ -0,0 +1,788 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/etcdhttp"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/v2auth"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+const (
+	authPrefix     = "/v2/auth"
+	keysPrefix     = "/v2/keys"
+	machinesPrefix = "/v2/machines"
+	membersPrefix  = "/v2/members"
+	statsPrefix    = "/v2/stats"
+)
+
+// NewClientHandler generates a muxed http.Handler with the given parameters to serve etcd client requests.
+func NewClientHandler(lg *zap.Logger, server etcdserver.ServerPeer, timeout time.Duration) http.Handler {
+	mux := http.NewServeMux()
+	etcdhttp.HandleBasic(mux, server)
+	handleV2(lg, mux, server, timeout)
+	return requestLogger(lg, mux)
+}
+
+func handleV2(lg *zap.Logger, mux *http.ServeMux, server etcdserver.ServerV2, timeout time.Duration) {
+	sec := v2auth.NewStore(lg, server, timeout)
+	kh := &keysHandler{
+		lg:                    lg,
+		sec:                   sec,
+		server:                server,
+		cluster:               server.Cluster(),
+		timeout:               timeout,
+		clientCertAuthEnabled: server.ClientCertAuthEnabled(),
+	}
+
+	sh := &statsHandler{
+		lg:    lg,
+		stats: server,
+	}
+
+	mh := &membersHandler{
+		lg:                    lg,
+		sec:                   sec,
+		server:                server,
+		cluster:               server.Cluster(),
+		timeout:               timeout,
+		clock:                 clockwork.NewRealClock(),
+		clientCertAuthEnabled: server.ClientCertAuthEnabled(),
+	}
+
+	mah := &machinesHandler{cluster: server.Cluster()}
+
+	sech := &authHandler{
+		lg:                    lg,
+		sec:                   sec,
+		cluster:               server.Cluster(),
+		clientCertAuthEnabled: server.ClientCertAuthEnabled(),
+	}
+	mux.HandleFunc("/", http.NotFound)
+	mux.Handle(keysPrefix, kh)
+	mux.Handle(keysPrefix+"/", kh)
+	mux.HandleFunc(statsPrefix+"/store", sh.serveStore)
+	mux.HandleFunc(statsPrefix+"/self", sh.serveSelf)
+	mux.HandleFunc(statsPrefix+"/leader", sh.serveLeader)
+	mux.Handle(membersPrefix, mh)
+	mux.Handle(membersPrefix+"/", mh)
+	mux.Handle(machinesPrefix, mah)
+	handleAuth(mux, sech)
+}
+
+type keysHandler struct {
+	lg                    *zap.Logger
+	sec                   v2auth.Store
+	server                etcdserver.ServerV2
+	cluster               api.Cluster
+	timeout               time.Duration
+	clientCertAuthEnabled bool
+}
+
+func (h *keysHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "HEAD", "GET", "PUT", "POST", "DELETE") {
+		return
+	}
+
+	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
+
+	ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
+	defer cancel()
+	clock := clockwork.NewRealClock()
+	startTime := clock.Now()
+	rr, noValueOnSuccess, err := parseKeyRequest(r, clock)
+	if err != nil {
+		writeKeyError(h.lg, w, err)
+		return
+	}
+	// The path must be valid at this point (we've parsed the request successfully).
+	if !hasKeyPrefixAccess(h.lg, h.sec, r, r.URL.Path[len(keysPrefix):], rr.Recursive, h.clientCertAuthEnabled) {
+		writeKeyNoAuth(w)
+		return
+	}
+	if !rr.Wait {
+		reportRequestReceived(rr)
+	}
+	resp, err := h.server.Do(ctx, rr)
+	if err != nil {
+		err = trimErrorPrefix(err, etcdserver.StoreKeysPrefix)
+		writeKeyError(h.lg, w, err)
+		reportRequestFailed(rr, err)
+		return
+	}
+	switch {
+	case resp.Event != nil:
+		if err := writeKeyEvent(w, resp, noValueOnSuccess); err != nil {
+			// Should never be reached
+			if h.lg != nil {
+				h.lg.Warn("failed to write key event", zap.Error(err))
+			} else {
+				plog.Errorf("error writing event (%v)", err)
+			}
+		}
+		reportRequestCompleted(rr, startTime)
+	case resp.Watcher != nil:
+		ctx, cancel := context.WithTimeout(context.Background(), defaultWatchTimeout)
+		defer cancel()
+		handleKeyWatch(ctx, h.lg, w, resp, rr.Stream)
+	default:
+		writeKeyError(h.lg, w, errors.New("received response with no Event/Watcher"))
+	}
+}
+
+type machinesHandler struct {
+	cluster api.Cluster
+}
+
+func (h *machinesHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET", "HEAD") {
+		return
+	}
+	endpoints := h.cluster.ClientURLs()
+	w.Write([]byte(strings.Join(endpoints, ", ")))
+}
+
+type membersHandler struct {
+	lg                    *zap.Logger
+	sec                   v2auth.Store
+	server                etcdserver.ServerV2
+	cluster               api.Cluster
+	timeout               time.Duration
+	clock                 clockwork.Clock
+	clientCertAuthEnabled bool
+}
+
+func (h *membersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET", "POST", "DELETE", "PUT") {
+		return
+	}
+	if !hasWriteRootAccess(h.lg, h.sec, r, h.clientCertAuthEnabled) {
+		writeNoAuth(h.lg, w, r)
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
+
+	ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
+	defer cancel()
+
+	switch r.Method {
+	case "GET":
+		switch trimPrefix(r.URL.Path, membersPrefix) {
+		case "":
+			mc := newMemberCollection(h.cluster.Members())
+			w.Header().Set("Content-Type", "application/json")
+			if err := json.NewEncoder(w).Encode(mc); err != nil {
+				if h.lg != nil {
+					h.lg.Warn("failed to encode members response", zap.Error(err))
+				} else {
+					plog.Warningf("failed to encode members response (%v)", err)
+				}
+			}
+		case "leader":
+			id := h.server.Leader()
+			if id == 0 {
+				writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusServiceUnavailable, "During election"))
+				return
+			}
+			m := newMember(h.cluster.Member(id))
+			w.Header().Set("Content-Type", "application/json")
+			if err := json.NewEncoder(w).Encode(m); err != nil {
+				if h.lg != nil {
+					h.lg.Warn("failed to encode members response", zap.Error(err))
+				} else {
+					plog.Warningf("failed to encode members response (%v)", err)
+				}
+			}
+		default:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusNotFound, "Not found"))
+		}
+
+	case "POST":
+		req := httptypes.MemberCreateRequest{}
+		if ok := unmarshalRequest(h.lg, r, &req, w); !ok {
+			return
+		}
+		now := h.clock.Now()
+		m := membership.NewMember("", req.PeerURLs, "", &now)
+		_, err := h.server.AddMember(ctx, *m)
+		switch {
+		case err == membership.ErrIDExists || err == membership.ErrPeerURLexists:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusConflict, err.Error()))
+			return
+		case err != nil:
+			if h.lg != nil {
+				h.lg.Warn(
+					"failed to add a member",
+					zap.String("member-id", m.ID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("error adding member %s (%v)", m.ID, err)
+			}
+			writeError(h.lg, w, r, err)
+			return
+		}
+		res := newMember(m)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusCreated)
+		if err := json.NewEncoder(w).Encode(res); err != nil {
+			if h.lg != nil {
+				h.lg.Warn("failed to encode members response", zap.Error(err))
+			} else {
+				plog.Warningf("failed to encode members response (%v)", err)
+			}
+		}
+
+	case "DELETE":
+		id, ok := getID(h.lg, r.URL.Path, w)
+		if !ok {
+			return
+		}
+		_, err := h.server.RemoveMember(ctx, uint64(id))
+		switch {
+		case err == membership.ErrIDRemoved:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusGone, fmt.Sprintf("Member permanently removed: %s", id)))
+		case err == membership.ErrIDNotFound:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusNotFound, fmt.Sprintf("No such member: %s", id)))
+		case err != nil:
+			if h.lg != nil {
+				h.lg.Warn(
+					"failed to remove a member",
+					zap.String("member-id", id.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("error removing member %s (%v)", id, err)
+			}
+			writeError(h.lg, w, r, err)
+		default:
+			w.WriteHeader(http.StatusNoContent)
+		}
+
+	case "PUT":
+		id, ok := getID(h.lg, r.URL.Path, w)
+		if !ok {
+			return
+		}
+		req := httptypes.MemberUpdateRequest{}
+		if ok := unmarshalRequest(h.lg, r, &req, w); !ok {
+			return
+		}
+		m := membership.Member{
+			ID:             id,
+			RaftAttributes: membership.RaftAttributes{PeerURLs: req.PeerURLs.StringSlice()},
+		}
+		_, err := h.server.UpdateMember(ctx, m)
+		switch {
+		case err == membership.ErrPeerURLexists:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusConflict, err.Error()))
+		case err == membership.ErrIDNotFound:
+			writeError(h.lg, w, r, httptypes.NewHTTPError(http.StatusNotFound, fmt.Sprintf("No such member: %s", id)))
+		case err != nil:
+			if h.lg != nil {
+				h.lg.Warn(
+					"failed to update a member",
+					zap.String("member-id", m.ID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("error updating member %s (%v)", m.ID, err)
+			}
+			writeError(h.lg, w, r, err)
+		default:
+			w.WriteHeader(http.StatusNoContent)
+		}
+	}
+}
+
+type statsHandler struct {
+	lg    *zap.Logger
+	stats stats.Stats
+}
+
+func (h *statsHandler) serveStore(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(h.stats.StoreStats())
+}
+
+func (h *statsHandler) serveSelf(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(h.stats.SelfStats())
+}
+
+func (h *statsHandler) serveLeader(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	stats := h.stats.LeaderStats()
+	if stats == nil {
+		etcdhttp.WriteError(h.lg, w, r, httptypes.NewHTTPError(http.StatusForbidden, "not current leader"))
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(stats)
+}
+
+// parseKeyRequest converts a received http.Request on keysPrefix to
+// a server Request, performing validation of supplied fields as appropriate.
+// If any validation fails, an empty Request and non-nil error is returned.
+func parseKeyRequest(r *http.Request, clock clockwork.Clock) (etcdserverpb.Request, bool, error) {
+	var noValueOnSuccess bool
+	emptyReq := etcdserverpb.Request{}
+
+	err := r.ParseForm()
+	if err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidForm,
+			err.Error(),
+		)
+	}
+
+	if !strings.HasPrefix(r.URL.Path, keysPrefix) {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidForm,
+			"incorrect key prefix",
+		)
+	}
+	p := path.Join(etcdserver.StoreKeysPrefix, r.URL.Path[len(keysPrefix):])
+
+	var pIdx, wIdx uint64
+	if pIdx, err = getUint64(r.Form, "prevIndex"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeIndexNaN,
+			`invalid value for "prevIndex"`,
+		)
+	}
+	if wIdx, err = getUint64(r.Form, "waitIndex"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeIndexNaN,
+			`invalid value for "waitIndex"`,
+		)
+	}
+
+	var rec, sort, wait, dir, quorum, stream bool
+	if rec, err = getBool(r.Form, "recursive"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "recursive"`,
+		)
+	}
+	if sort, err = getBool(r.Form, "sorted"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "sorted"`,
+		)
+	}
+	if wait, err = getBool(r.Form, "wait"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "wait"`,
+		)
+	}
+	// TODO(jonboulle): define what parameters dir is/isn't compatible with?
+	if dir, err = getBool(r.Form, "dir"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "dir"`,
+		)
+	}
+	if quorum, err = getBool(r.Form, "quorum"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "quorum"`,
+		)
+	}
+	if stream, err = getBool(r.Form, "stream"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "stream"`,
+		)
+	}
+
+	if wait && r.Method != "GET" {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`"wait" can only be used with GET requests`,
+		)
+	}
+
+	pV := r.FormValue("prevValue")
+	if _, ok := r.Form["prevValue"]; ok && pV == "" {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodePrevValueRequired,
+			`"prevValue" cannot be empty`,
+		)
+	}
+
+	if noValueOnSuccess, err = getBool(r.Form, "noValueOnSuccess"); err != nil {
+		return emptyReq, false, v2error.NewRequestError(
+			v2error.EcodeInvalidField,
+			`invalid value for "noValueOnSuccess"`,
+		)
+	}
+
+	// TTL is nullable, so leave it null if not specified
+	// or an empty string
+	var ttl *uint64
+	if len(r.FormValue("ttl")) > 0 {
+		i, err := getUint64(r.Form, "ttl")
+		if err != nil {
+			return emptyReq, false, v2error.NewRequestError(
+				v2error.EcodeTTLNaN,
+				`invalid value for "ttl"`,
+			)
+		}
+		ttl = &i
+	}
+
+	// prevExist is nullable, so leave it null if not specified
+	var pe *bool
+	if _, ok := r.Form["prevExist"]; ok {
+		bv, err := getBool(r.Form, "prevExist")
+		if err != nil {
+			return emptyReq, false, v2error.NewRequestError(
+				v2error.EcodeInvalidField,
+				"invalid value for prevExist",
+			)
+		}
+		pe = &bv
+	}
+
+	// refresh is nullable, so leave it null if not specified
+	var refresh *bool
+	if _, ok := r.Form["refresh"]; ok {
+		bv, err := getBool(r.Form, "refresh")
+		if err != nil {
+			return emptyReq, false, v2error.NewRequestError(
+				v2error.EcodeInvalidField,
+				"invalid value for refresh",
+			)
+		}
+		refresh = &bv
+		if refresh != nil && *refresh {
+			val := r.FormValue("value")
+			if _, ok := r.Form["value"]; ok && val != "" {
+				return emptyReq, false, v2error.NewRequestError(
+					v2error.EcodeRefreshValue,
+					`A value was provided on a refresh`,
+				)
+			}
+			if ttl == nil {
+				return emptyReq, false, v2error.NewRequestError(
+					v2error.EcodeRefreshTTLRequired,
+					`No TTL value set`,
+				)
+			}
+		}
+	}
+
+	rr := etcdserverpb.Request{
+		Method:    r.Method,
+		Path:      p,
+		Val:       r.FormValue("value"),
+		Dir:       dir,
+		PrevValue: pV,
+		PrevIndex: pIdx,
+		PrevExist: pe,
+		Wait:      wait,
+		Since:     wIdx,
+		Recursive: rec,
+		Sorted:    sort,
+		Quorum:    quorum,
+		Stream:    stream,
+	}
+
+	if pe != nil {
+		rr.PrevExist = pe
+	}
+
+	if refresh != nil {
+		rr.Refresh = refresh
+	}
+
+	// Null TTL is equivalent to unset Expiration
+	if ttl != nil {
+		expr := time.Duration(*ttl) * time.Second
+		rr.Expiration = clock.Now().Add(expr).UnixNano()
+	}
+
+	return rr, noValueOnSuccess, nil
+}
+
+// writeKeyEvent trims the prefix of key path in a single Event under
+// StoreKeysPrefix, serializes it and writes the resulting JSON to the given
+// ResponseWriter, along with the appropriate headers.
+func writeKeyEvent(w http.ResponseWriter, resp etcdserver.Response, noValueOnSuccess bool) error {
+	ev := resp.Event
+	if ev == nil {
+		return errors.New("cannot write empty Event")
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("X-Etcd-Index", fmt.Sprint(ev.EtcdIndex))
+	w.Header().Set("X-Raft-Index", fmt.Sprint(resp.Index))
+	w.Header().Set("X-Raft-Term", fmt.Sprint(resp.Term))
+
+	if ev.IsCreated() {
+		w.WriteHeader(http.StatusCreated)
+	}
+
+	ev = trimEventPrefix(ev, etcdserver.StoreKeysPrefix)
+	if noValueOnSuccess &&
+		(ev.Action == v2store.Set || ev.Action == v2store.CompareAndSwap ||
+			ev.Action == v2store.Create || ev.Action == v2store.Update) {
+		ev.Node = nil
+		ev.PrevNode = nil
+	}
+	return json.NewEncoder(w).Encode(ev)
+}
+
+func writeKeyNoAuth(w http.ResponseWriter) {
+	e := v2error.NewError(v2error.EcodeUnauthorized, "Insufficient credentials", 0)
+	e.WriteTo(w)
+}
+
+// writeKeyError logs and writes the given Error to the ResponseWriter.
+// If Error is not an etcdErr, the error will be converted to an etcd error.
+func writeKeyError(lg *zap.Logger, w http.ResponseWriter, err error) {
+	if err == nil {
+		return
+	}
+	switch e := err.(type) {
+	case *v2error.Error:
+		e.WriteTo(w)
+	default:
+		switch err {
+		case etcdserver.ErrTimeoutDueToLeaderFail, etcdserver.ErrTimeoutDueToConnectionLost:
+			if lg != nil {
+				lg.Warn(
+					"v2 response error",
+					zap.String("internal-server-error", err.Error()),
+				)
+			} else {
+				mlog.MergeError(err)
+			}
+		default:
+			if lg != nil {
+				lg.Warn(
+					"unexpected v2 response error",
+					zap.String("internal-server-error", err.Error()),
+				)
+			} else {
+				mlog.MergeErrorf("got unexpected response error (%v)", err)
+			}
+		}
+		ee := v2error.NewError(v2error.EcodeRaftInternal, err.Error(), 0)
+		ee.WriteTo(w)
+	}
+}
+
+func handleKeyWatch(ctx context.Context, lg *zap.Logger, w http.ResponseWriter, resp etcdserver.Response, stream bool) {
+	wa := resp.Watcher
+	defer wa.Remove()
+	ech := wa.EventChan()
+	var nch <-chan bool
+	if x, ok := w.(http.CloseNotifier); ok {
+		nch = x.CloseNotify()
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("X-Etcd-Index", fmt.Sprint(wa.StartIndex()))
+	w.Header().Set("X-Raft-Index", fmt.Sprint(resp.Index))
+	w.Header().Set("X-Raft-Term", fmt.Sprint(resp.Term))
+	w.WriteHeader(http.StatusOK)
+
+	// Ensure headers are flushed early, in case of long polling
+	w.(http.Flusher).Flush()
+
+	for {
+		select {
+		case <-nch:
+			// Client closed connection. Nothing to do.
+			return
+		case <-ctx.Done():
+			// Timed out. net/http will close the connection for us, so nothing to do.
+			return
+		case ev, ok := <-ech:
+			if !ok {
+				// If the channel is closed this may be an indication of
+				// that notifications are much more than we are able to
+				// send to the client in time. Then we simply end streaming.
+				return
+			}
+			ev = trimEventPrefix(ev, etcdserver.StoreKeysPrefix)
+			if err := json.NewEncoder(w).Encode(ev); err != nil {
+				// Should never be reached
+				if lg != nil {
+					lg.Warn("failed to encode event", zap.Error(err))
+				} else {
+					plog.Warningf("error writing event (%v)", err)
+				}
+				return
+			}
+			if !stream {
+				return
+			}
+			w.(http.Flusher).Flush()
+		}
+	}
+}
+
+func trimEventPrefix(ev *v2store.Event, prefix string) *v2store.Event {
+	if ev == nil {
+		return nil
+	}
+	// Since the *Event may reference one in the store history
+	// history, we must copy it before modifying
+	e := ev.Clone()
+	trimNodeExternPrefix(e.Node, prefix)
+	trimNodeExternPrefix(e.PrevNode, prefix)
+	return e
+}
+
+func trimNodeExternPrefix(n *v2store.NodeExtern, prefix string) {
+	if n == nil {
+		return
+	}
+	n.Key = strings.TrimPrefix(n.Key, prefix)
+	for _, nn := range n.Nodes {
+		trimNodeExternPrefix(nn, prefix)
+	}
+}
+
+func trimErrorPrefix(err error, prefix string) error {
+	if e, ok := err.(*v2error.Error); ok {
+		e.Cause = strings.TrimPrefix(e.Cause, prefix)
+	}
+	return err
+}
+
+func unmarshalRequest(lg *zap.Logger, r *http.Request, req json.Unmarshaler, w http.ResponseWriter) bool {
+	ctype := r.Header.Get("Content-Type")
+	semicolonPosition := strings.Index(ctype, ";")
+	if semicolonPosition != -1 {
+		ctype = strings.TrimSpace(strings.ToLower(ctype[0:semicolonPosition]))
+	}
+	if ctype != "application/json" {
+		writeError(lg, w, r, httptypes.NewHTTPError(http.StatusUnsupportedMediaType, fmt.Sprintf("Bad Content-Type %s, accept application/json", ctype)))
+		return false
+	}
+	b, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		writeError(lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, err.Error()))
+		return false
+	}
+	if err := req.UnmarshalJSON(b); err != nil {
+		writeError(lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, err.Error()))
+		return false
+	}
+	return true
+}
+
+func getID(lg *zap.Logger, p string, w http.ResponseWriter) (types.ID, bool) {
+	idStr := trimPrefix(p, membersPrefix)
+	if idStr == "" {
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return 0, false
+	}
+	id, err := types.IDFromString(idStr)
+	if err != nil {
+		writeError(lg, w, nil, httptypes.NewHTTPError(http.StatusNotFound, fmt.Sprintf("No such member: %s", idStr)))
+		return 0, false
+	}
+	return id, true
+}
+
+// getUint64 extracts a uint64 by the given key from a Form. If the key does
+// not exist in the form, 0 is returned. If the key exists but the value is
+// badly formed, an error is returned. If multiple values are present only the
+// first is considered.
+func getUint64(form url.Values, key string) (i uint64, err error) {
+	if vals, ok := form[key]; ok {
+		i, err = strconv.ParseUint(vals[0], 10, 64)
+	}
+	return
+}
+
+// getBool extracts a bool by the given key from a Form. If the key does not
+// exist in the form, false is returned. If the key exists but the value is
+// badly formed, an error is returned. If multiple values are present only the
+// first is considered.
+func getBool(form url.Values, key string) (b bool, err error) {
+	if vals, ok := form[key]; ok {
+		b, err = strconv.ParseBool(vals[0])
+	}
+	return
+}
+
+// trimPrefix removes a given prefix and any slash following the prefix
+// e.g.: trimPrefix("foo", "foo") == trimPrefix("foo/", "foo") == ""
+func trimPrefix(p, prefix string) (s string) {
+	s = strings.TrimPrefix(p, prefix)
+	s = strings.TrimPrefix(s, "/")
+	return
+}
+
+func newMemberCollection(ms []*membership.Member) *httptypes.MemberCollection {
+	c := httptypes.MemberCollection(make([]httptypes.Member, len(ms)))
+
+	for i, m := range ms {
+		c[i] = newMember(m)
+	}
+
+	return &c
+}
+
+func newMember(m *membership.Member) httptypes.Member {
+	tm := httptypes.Member{
+		ID:         m.ID.String(),
+		Name:       m.Name,
+		PeerURLs:   make([]string, len(m.PeerURLs)),
+		ClientURLs: make([]string, len(m.ClientURLs)),
+	}
+
+	copy(tm.PeerURLs, m.PeerURLs)
+	copy(tm.ClientURLs, m.ClientURLs)
+
+	return tm
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client_auth.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client_auth.go
new file mode 100644
index 0000000..d8d6a88
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/client_auth.go
@@ -0,0 +1,664 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"encoding/json"
+	"net/http"
+	"path"
+	"strings"
+
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/v2auth"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+
+	"go.uber.org/zap"
+)
+
+type authHandler struct {
+	lg                    *zap.Logger
+	sec                   v2auth.Store
+	cluster               api.Cluster
+	clientCertAuthEnabled bool
+}
+
+func hasWriteRootAccess(lg *zap.Logger, sec v2auth.Store, r *http.Request, clientCertAuthEnabled bool) bool {
+	if r.Method == "GET" || r.Method == "HEAD" {
+		return true
+	}
+	return hasRootAccess(lg, sec, r, clientCertAuthEnabled)
+}
+
+func userFromBasicAuth(lg *zap.Logger, sec v2auth.Store, r *http.Request) *v2auth.User {
+	username, password, ok := r.BasicAuth()
+	if !ok {
+		if lg != nil {
+			lg.Warn("malformed basic auth encoding")
+		} else {
+			plog.Warningf("auth: malformed basic auth encoding")
+		}
+		return nil
+	}
+	user, err := sec.GetUser(username)
+	if err != nil {
+		return nil
+	}
+
+	ok = sec.CheckPassword(user, password)
+	if !ok {
+		if lg != nil {
+			lg.Warn("incorrect password", zap.String("user-name", username))
+		} else {
+			plog.Warningf("auth: incorrect password for user: %s", username)
+		}
+		return nil
+	}
+	return &user
+}
+
+func userFromClientCertificate(lg *zap.Logger, sec v2auth.Store, r *http.Request) *v2auth.User {
+	if r.TLS == nil {
+		return nil
+	}
+
+	for _, chains := range r.TLS.VerifiedChains {
+		for _, chain := range chains {
+			if lg != nil {
+				lg.Debug("found common name", zap.String("common-name", chain.Subject.CommonName))
+			} else {
+				plog.Debugf("auth: found common name %s.\n", chain.Subject.CommonName)
+			}
+			user, err := sec.GetUser(chain.Subject.CommonName)
+			if err == nil {
+				if lg != nil {
+					lg.Debug(
+						"authenticated a user via common name",
+						zap.String("user-name", user.User),
+						zap.String("common-name", chain.Subject.CommonName),
+					)
+				} else {
+					plog.Debugf("auth: authenticated user %s by cert common name.", user.User)
+				}
+				return &user
+			}
+		}
+	}
+	return nil
+}
+
+func hasRootAccess(lg *zap.Logger, sec v2auth.Store, r *http.Request, clientCertAuthEnabled bool) bool {
+	if sec == nil {
+		// No store means no auth available, eg, tests.
+		return true
+	}
+	if !sec.AuthEnabled() {
+		return true
+	}
+
+	var rootUser *v2auth.User
+	if r.Header.Get("Authorization") == "" && clientCertAuthEnabled {
+		rootUser = userFromClientCertificate(lg, sec, r)
+		if rootUser == nil {
+			return false
+		}
+	} else {
+		rootUser = userFromBasicAuth(lg, sec, r)
+		if rootUser == nil {
+			return false
+		}
+	}
+
+	for _, role := range rootUser.Roles {
+		if role == v2auth.RootRoleName {
+			return true
+		}
+	}
+
+	if lg != nil {
+		lg.Warn(
+			"a user does not have root role for resource",
+			zap.String("root-user", rootUser.User),
+			zap.String("root-role-name", v2auth.RootRoleName),
+			zap.String("resource-path", r.URL.Path),
+		)
+	} else {
+		plog.Warningf("auth: user %s does not have the %s role for resource %s.", rootUser.User, v2auth.RootRoleName, r.URL.Path)
+	}
+	return false
+}
+
+func hasKeyPrefixAccess(lg *zap.Logger, sec v2auth.Store, r *http.Request, key string, recursive, clientCertAuthEnabled bool) bool {
+	if sec == nil {
+		// No store means no auth available, eg, tests.
+		return true
+	}
+	if !sec.AuthEnabled() {
+		return true
+	}
+
+	var user *v2auth.User
+	if r.Header.Get("Authorization") == "" {
+		if clientCertAuthEnabled {
+			user = userFromClientCertificate(lg, sec, r)
+		}
+		if user == nil {
+			return hasGuestAccess(lg, sec, r, key)
+		}
+	} else {
+		user = userFromBasicAuth(lg, sec, r)
+		if user == nil {
+			return false
+		}
+	}
+
+	writeAccess := r.Method != "GET" && r.Method != "HEAD"
+	for _, roleName := range user.Roles {
+		role, err := sec.GetRole(roleName)
+		if err != nil {
+			continue
+		}
+		if recursive {
+			if role.HasRecursiveAccess(key, writeAccess) {
+				return true
+			}
+		} else if role.HasKeyAccess(key, writeAccess) {
+			return true
+		}
+	}
+
+	if lg != nil {
+		lg.Warn(
+			"invalid access for user on key",
+			zap.String("user-name", user.User),
+			zap.String("key", key),
+		)
+	} else {
+		plog.Warningf("auth: invalid access for user %s on key %s.", user.User, key)
+	}
+	return false
+}
+
+func hasGuestAccess(lg *zap.Logger, sec v2auth.Store, r *http.Request, key string) bool {
+	writeAccess := r.Method != "GET" && r.Method != "HEAD"
+	role, err := sec.GetRole(v2auth.GuestRoleName)
+	if err != nil {
+		return false
+	}
+	if role.HasKeyAccess(key, writeAccess) {
+		return true
+	}
+
+	if lg != nil {
+		lg.Warn(
+			"invalid access for a guest role on key",
+			zap.String("role-name", v2auth.GuestRoleName),
+			zap.String("key", key),
+		)
+	} else {
+		plog.Warningf("auth: invalid access for unauthenticated user on resource %s.", key)
+	}
+	return false
+}
+
+func writeNoAuth(lg *zap.Logger, w http.ResponseWriter, r *http.Request) {
+	herr := httptypes.NewHTTPError(http.StatusUnauthorized, "Insufficient credentials")
+	if err := herr.WriteTo(w); err != nil {
+		if lg != nil {
+			lg.Debug(
+				"failed to write v2 HTTP error",
+				zap.String("remote-addr", r.RemoteAddr),
+				zap.Error(err),
+			)
+		} else {
+			plog.Debugf("error writing HTTPError (%v) to %s", err, r.RemoteAddr)
+		}
+	}
+}
+
+func handleAuth(mux *http.ServeMux, sh *authHandler) {
+	mux.HandleFunc(authPrefix+"/roles", authCapabilityHandler(sh.baseRoles))
+	mux.HandleFunc(authPrefix+"/roles/", authCapabilityHandler(sh.handleRoles))
+	mux.HandleFunc(authPrefix+"/users", authCapabilityHandler(sh.baseUsers))
+	mux.HandleFunc(authPrefix+"/users/", authCapabilityHandler(sh.handleUsers))
+	mux.HandleFunc(authPrefix+"/enable", authCapabilityHandler(sh.enableDisable))
+}
+
+func (sh *authHandler) baseRoles(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	if !hasRootAccess(sh.lg, sh.sec, r, sh.clientCertAuthEnabled) {
+		writeNoAuth(sh.lg, w, r)
+		return
+	}
+
+	w.Header().Set("X-Etcd-Cluster-ID", sh.cluster.ID().String())
+	w.Header().Set("Content-Type", "application/json")
+
+	roles, err := sh.sec.AllRoles()
+	if err != nil {
+		writeError(sh.lg, w, r, err)
+		return
+	}
+	if roles == nil {
+		roles = make([]string, 0)
+	}
+
+	err = r.ParseForm()
+	if err != nil {
+		writeError(sh.lg, w, r, err)
+		return
+	}
+
+	var rolesCollections struct {
+		Roles []v2auth.Role `json:"roles"`
+	}
+	for _, roleName := range roles {
+		var role v2auth.Role
+		role, err = sh.sec.GetRole(roleName)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+		rolesCollections.Roles = append(rolesCollections.Roles, role)
+	}
+	err = json.NewEncoder(w).Encode(rolesCollections)
+
+	if err != nil {
+		if sh.lg != nil {
+			sh.lg.Warn(
+				"failed to encode base roles",
+				zap.String("url", r.URL.String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Warningf("baseRoles error encoding on %s", r.URL)
+		}
+		writeError(sh.lg, w, r, err)
+		return
+	}
+}
+
+func (sh *authHandler) handleRoles(w http.ResponseWriter, r *http.Request) {
+	subpath := path.Clean(r.URL.Path[len(authPrefix):])
+	// Split "/roles/rolename/command".
+	// First item is an empty string, second is "roles"
+	pieces := strings.Split(subpath, "/")
+	if len(pieces) == 2 {
+		sh.baseRoles(w, r)
+		return
+	}
+	if len(pieces) != 3 {
+		writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid path"))
+		return
+	}
+	sh.forRole(w, r, pieces[2])
+}
+
+func (sh *authHandler) forRole(w http.ResponseWriter, r *http.Request, role string) {
+	if !allowMethod(w, r.Method, "GET", "PUT", "DELETE") {
+		return
+	}
+	if !hasRootAccess(sh.lg, sh.sec, r, sh.clientCertAuthEnabled) {
+		writeNoAuth(sh.lg, w, r)
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", sh.cluster.ID().String())
+	w.Header().Set("Content-Type", "application/json")
+
+	switch r.Method {
+	case "GET":
+		data, err := sh.sec.GetRole(role)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+		err = json.NewEncoder(w).Encode(data)
+		if err != nil {
+			if sh.lg != nil {
+				sh.lg.Warn(
+					"failed to encode a role",
+					zap.String("url", r.URL.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("forRole error encoding on %s", r.URL)
+			}
+			return
+		}
+		return
+
+	case "PUT":
+		var in v2auth.Role
+		err := json.NewDecoder(r.Body).Decode(&in)
+		if err != nil {
+			writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid JSON in request body."))
+			return
+		}
+		if in.Role != role {
+			writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Role JSON name does not match the name in the URL"))
+			return
+		}
+
+		var out v2auth.Role
+
+		// create
+		if in.Grant.IsEmpty() && in.Revoke.IsEmpty() {
+			err = sh.sec.CreateRole(in)
+			if err != nil {
+				writeError(sh.lg, w, r, err)
+				return
+			}
+			w.WriteHeader(http.StatusCreated)
+			out = in
+		} else {
+			if !in.Permissions.IsEmpty() {
+				writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Role JSON contains both permissions and grant/revoke"))
+				return
+			}
+			out, err = sh.sec.UpdateRole(in)
+			if err != nil {
+				writeError(sh.lg, w, r, err)
+				return
+			}
+			w.WriteHeader(http.StatusOK)
+		}
+
+		err = json.NewEncoder(w).Encode(out)
+		if err != nil {
+			if sh.lg != nil {
+				sh.lg.Warn(
+					"failed to encode a role",
+					zap.String("url", r.URL.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("forRole error encoding on %s", r.URL)
+			}
+			return
+		}
+		return
+
+	case "DELETE":
+		err := sh.sec.DeleteRole(role)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+	}
+}
+
+type userWithRoles struct {
+	User  string        `json:"user"`
+	Roles []v2auth.Role `json:"roles,omitempty"`
+}
+
+type usersCollections struct {
+	Users []userWithRoles `json:"users"`
+}
+
+func (sh *authHandler) baseUsers(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET") {
+		return
+	}
+	if !hasRootAccess(sh.lg, sh.sec, r, sh.clientCertAuthEnabled) {
+		writeNoAuth(sh.lg, w, r)
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", sh.cluster.ID().String())
+	w.Header().Set("Content-Type", "application/json")
+
+	users, err := sh.sec.AllUsers()
+	if err != nil {
+		writeError(sh.lg, w, r, err)
+		return
+	}
+	if users == nil {
+		users = make([]string, 0)
+	}
+
+	err = r.ParseForm()
+	if err != nil {
+		writeError(sh.lg, w, r, err)
+		return
+	}
+
+	ucs := usersCollections{}
+	for _, userName := range users {
+		var user v2auth.User
+		user, err = sh.sec.GetUser(userName)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+
+		uwr := userWithRoles{User: user.User}
+		for _, roleName := range user.Roles {
+			var role v2auth.Role
+			role, err = sh.sec.GetRole(roleName)
+			if err != nil {
+				continue
+			}
+			uwr.Roles = append(uwr.Roles, role)
+		}
+
+		ucs.Users = append(ucs.Users, uwr)
+	}
+	err = json.NewEncoder(w).Encode(ucs)
+
+	if err != nil {
+		if sh.lg != nil {
+			sh.lg.Warn(
+				"failed to encode users",
+				zap.String("url", r.URL.String()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Warningf("baseUsers error encoding on %s", r.URL)
+		}
+		writeError(sh.lg, w, r, err)
+		return
+	}
+}
+
+func (sh *authHandler) handleUsers(w http.ResponseWriter, r *http.Request) {
+	subpath := path.Clean(r.URL.Path[len(authPrefix):])
+	// Split "/users/username".
+	// First item is an empty string, second is "users"
+	pieces := strings.Split(subpath, "/")
+	if len(pieces) == 2 {
+		sh.baseUsers(w, r)
+		return
+	}
+	if len(pieces) != 3 {
+		writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid path"))
+		return
+	}
+	sh.forUser(w, r, pieces[2])
+}
+
+func (sh *authHandler) forUser(w http.ResponseWriter, r *http.Request, user string) {
+	if !allowMethod(w, r.Method, "GET", "PUT", "DELETE") {
+		return
+	}
+	if !hasRootAccess(sh.lg, sh.sec, r, sh.clientCertAuthEnabled) {
+		writeNoAuth(sh.lg, w, r)
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", sh.cluster.ID().String())
+	w.Header().Set("Content-Type", "application/json")
+
+	switch r.Method {
+	case "GET":
+		u, err := sh.sec.GetUser(user)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+
+		err = r.ParseForm()
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+
+		uwr := userWithRoles{User: u.User}
+		for _, roleName := range u.Roles {
+			var role v2auth.Role
+			role, err = sh.sec.GetRole(roleName)
+			if err != nil {
+				writeError(sh.lg, w, r, err)
+				return
+			}
+			uwr.Roles = append(uwr.Roles, role)
+		}
+		err = json.NewEncoder(w).Encode(uwr)
+
+		if err != nil {
+			if sh.lg != nil {
+				sh.lg.Warn(
+					"failed to encode roles",
+					zap.String("url", r.URL.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("forUser error encoding on %s", r.URL)
+			}
+			return
+		}
+		return
+
+	case "PUT":
+		var u v2auth.User
+		err := json.NewDecoder(r.Body).Decode(&u)
+		if err != nil {
+			writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "Invalid JSON in request body."))
+			return
+		}
+		if u.User != user {
+			writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "User JSON name does not match the name in the URL"))
+			return
+		}
+
+		var (
+			out     v2auth.User
+			created bool
+		)
+
+		if len(u.Grant) == 0 && len(u.Revoke) == 0 {
+			// create or update
+			if len(u.Roles) != 0 {
+				out, err = sh.sec.CreateUser(u)
+			} else {
+				// if user passes in both password and roles, we are unsure about his/her
+				// intention.
+				out, created, err = sh.sec.CreateOrUpdateUser(u)
+			}
+
+			if err != nil {
+				writeError(sh.lg, w, r, err)
+				return
+			}
+		} else {
+			// update case
+			if len(u.Roles) != 0 {
+				writeError(sh.lg, w, r, httptypes.NewHTTPError(http.StatusBadRequest, "User JSON contains both roles and grant/revoke"))
+				return
+			}
+			out, err = sh.sec.UpdateUser(u)
+			if err != nil {
+				writeError(sh.lg, w, r, err)
+				return
+			}
+		}
+
+		if created {
+			w.WriteHeader(http.StatusCreated)
+		} else {
+			w.WriteHeader(http.StatusOK)
+		}
+
+		out.Password = ""
+
+		err = json.NewEncoder(w).Encode(out)
+		if err != nil {
+			if sh.lg != nil {
+				sh.lg.Warn(
+					"failed to encode a user",
+					zap.String("url", r.URL.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("forUser error encoding on %s", r.URL)
+			}
+			return
+		}
+		return
+
+	case "DELETE":
+		err := sh.sec.DeleteUser(user)
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+	}
+}
+
+type enabled struct {
+	Enabled bool `json:"enabled"`
+}
+
+func (sh *authHandler) enableDisable(w http.ResponseWriter, r *http.Request) {
+	if !allowMethod(w, r.Method, "GET", "PUT", "DELETE") {
+		return
+	}
+	if !hasWriteRootAccess(sh.lg, sh.sec, r, sh.clientCertAuthEnabled) {
+		writeNoAuth(sh.lg, w, r)
+		return
+	}
+	w.Header().Set("X-Etcd-Cluster-ID", sh.cluster.ID().String())
+	w.Header().Set("Content-Type", "application/json")
+	isEnabled := sh.sec.AuthEnabled()
+	switch r.Method {
+	case "GET":
+		jsonDict := enabled{isEnabled}
+		err := json.NewEncoder(w).Encode(jsonDict)
+		if err != nil {
+			if sh.lg != nil {
+				sh.lg.Warn(
+					"failed to encode a auth state",
+					zap.String("url", r.URL.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("error encoding auth state on %s", r.URL)
+			}
+		}
+
+	case "PUT":
+		err := sh.sec.EnableAuth()
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+
+	case "DELETE":
+		err := sh.sec.DisableAuth()
+		if err != nil {
+			writeError(sh.lg, w, r, err)
+			return
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/doc.go
new file mode 100644
index 0000000..475c4b1
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2http provides etcd client and server implementations.
+package v2http
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/http.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/http.go
new file mode 100644
index 0000000..c695689
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/http.go
@@ -0,0 +1,93 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"math"
+	"net/http"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/etcdhttp"
+	"go.etcd.io/etcd/etcdserver/api/v2auth"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+	"go.etcd.io/etcd/pkg/logutil"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+)
+
+const (
+	// time to wait for a Watch request
+	defaultWatchTimeout = time.Duration(math.MaxInt64)
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api/v2http")
+	mlog = logutil.NewMergeLogger(plog)
+)
+
+func writeError(lg *zap.Logger, w http.ResponseWriter, r *http.Request, err error) {
+	if err == nil {
+		return
+	}
+	if e, ok := err.(v2auth.Error); ok {
+		herr := httptypes.NewHTTPError(e.HTTPStatus(), e.Error())
+		if et := herr.WriteTo(w); et != nil {
+			if lg != nil {
+				lg.Debug(
+					"failed to write v2 HTTP error",
+					zap.String("remote-addr", r.RemoteAddr),
+					zap.String("v2auth-error", e.Error()),
+					zap.Error(et),
+				)
+			} else {
+				plog.Debugf("error writing HTTPError (%v) to %s", et, r.RemoteAddr)
+			}
+		}
+		return
+	}
+	etcdhttp.WriteError(lg, w, r, err)
+}
+
+// allowMethod verifies that the given method is one of the allowed methods,
+// and if not, it writes an error to w.  A boolean is returned indicating
+// whether or not the method is allowed.
+func allowMethod(w http.ResponseWriter, m string, ms ...string) bool {
+	for _, meth := range ms {
+		if m == meth {
+			return true
+		}
+	}
+	w.Header().Set("Allow", strings.Join(ms, ","))
+	http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+	return false
+}
+
+func requestLogger(lg *zap.Logger, handler http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if lg != nil {
+			lg.Debug(
+				"handling HTTP request",
+				zap.String("method", r.Method),
+				zap.String("request-uri", r.RequestURI),
+				zap.String("remote-addr", r.RemoteAddr),
+			)
+		} else {
+			plog.Debugf("[%s] %s remote:%s", r.Method, r.RequestURI, r.RemoteAddr)
+		}
+		handler.ServeHTTP(w, r)
+	})
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/errors.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/errors.go
new file mode 100644
index 0000000..245c089
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/errors.go
@@ -0,0 +1,56 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httptypes
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api/v2http/httptypes")
+)
+
+type HTTPError struct {
+	Message string `json:"message"`
+	// Code is the HTTP status code
+	Code int `json:"-"`
+}
+
+func (e HTTPError) Error() string {
+	return e.Message
+}
+
+func (e HTTPError) WriteTo(w http.ResponseWriter) error {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(e.Code)
+	b, err := json.Marshal(e)
+	if err != nil {
+		plog.Panicf("marshal HTTPError should never fail (%v)", err)
+	}
+	if _, err := w.Write(b); err != nil {
+		return err
+	}
+	return nil
+}
+
+func NewHTTPError(code int, m string) *HTTPError {
+	return &HTTPError{
+		Message: m,
+		Code:    code,
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/member.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/member.go
new file mode 100644
index 0000000..95fd443
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/httptypes/member.go
@@ -0,0 +1,69 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package httptypes defines how etcd's HTTP API entities are serialized to and
+// deserialized from JSON.
+package httptypes
+
+import (
+	"encoding/json"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+type Member struct {
+	ID         string   `json:"id"`
+	Name       string   `json:"name"`
+	PeerURLs   []string `json:"peerURLs"`
+	ClientURLs []string `json:"clientURLs"`
+}
+
+type MemberCreateRequest struct {
+	PeerURLs types.URLs
+}
+
+type MemberUpdateRequest struct {
+	MemberCreateRequest
+}
+
+func (m *MemberCreateRequest) UnmarshalJSON(data []byte) error {
+	s := struct {
+		PeerURLs []string `json:"peerURLs"`
+	}{}
+
+	err := json.Unmarshal(data, &s)
+	if err != nil {
+		return err
+	}
+
+	urls, err := types.NewURLs(s.PeerURLs)
+	if err != nil {
+		return err
+	}
+
+	m.PeerURLs = urls
+	return nil
+}
+
+type MemberCollection []Member
+
+func (c *MemberCollection) MarshalJSON() ([]byte, error) {
+	d := struct {
+		Members []Member `json:"members"`
+	}{
+		Members: []Member(*c),
+	}
+
+	return json.Marshal(d)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2http/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/metrics.go
new file mode 100644
index 0000000..14f7da0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2http/metrics.go
@@ -0,0 +1,99 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2http
+
+import (
+	"strconv"
+	"time"
+
+	"net/http"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	incomingEvents = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "received_total",
+			Help:      "Counter of requests received into the system (successfully parsed and authd).",
+		}, []string{"method"})
+
+	failedEvents = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "failed_total",
+			Help:      "Counter of handle failures of requests (non-watches), by method (GET/PUT etc.) and code (400, 500 etc.).",
+		}, []string{"method", "code"})
+
+	successfulEventsHandlingSec = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Namespace: "etcd",
+			Subsystem: "http",
+			Name:      "successful_duration_seconds",
+			Help:      "Bucketed histogram of processing time (s) of successfully handled requests (non-watches), by method (GET/PUT etc.).",
+
+			// lowest bucket start of upper bound 0.0005 sec (0.5 ms) with factor 2
+			// highest bucket start of 0.0005 sec * 2^12 == 2.048 sec
+			Buckets: prometheus.ExponentialBuckets(0.0005, 2, 13),
+		}, []string{"method"})
+)
+
+func init() {
+	prometheus.MustRegister(incomingEvents)
+	prometheus.MustRegister(failedEvents)
+	prometheus.MustRegister(successfulEventsHandlingSec)
+}
+
+func reportRequestReceived(request etcdserverpb.Request) {
+	incomingEvents.WithLabelValues(methodFromRequest(request)).Inc()
+}
+
+func reportRequestCompleted(request etcdserverpb.Request, startTime time.Time) {
+	method := methodFromRequest(request)
+	successfulEventsHandlingSec.WithLabelValues(method).Observe(time.Since(startTime).Seconds())
+}
+
+func reportRequestFailed(request etcdserverpb.Request, err error) {
+	method := methodFromRequest(request)
+	failedEvents.WithLabelValues(method, strconv.Itoa(codeFromError(err))).Inc()
+}
+
+func methodFromRequest(request etcdserverpb.Request) string {
+	if request.Method == "GET" && request.Quorum {
+		return "QGET"
+	}
+	return request.Method
+}
+
+func codeFromError(err error) int {
+	if err == nil {
+		return http.StatusInternalServerError
+	}
+	switch e := err.(type) {
+	case *v2error.Error:
+		return e.StatusCode()
+	case *httptypes.HTTPError:
+		return e.Code
+	default:
+		return http.StatusInternalServerError
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/leader.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/leader.go
new file mode 100644
index 0000000..ca47f0f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/leader.go
@@ -0,0 +1,128 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2stats
+
+import (
+	"encoding/json"
+	"math"
+	"sync"
+	"time"
+)
+
+// LeaderStats is used by the leader in an etcd cluster, and encapsulates
+// statistics about communication with its followers
+type LeaderStats struct {
+	leaderStats
+	sync.Mutex
+}
+
+type leaderStats struct {
+	// Leader is the ID of the leader in the etcd cluster.
+	// TODO(jonboulle): clarify that these are IDs, not names
+	Leader    string                    `json:"leader"`
+	Followers map[string]*FollowerStats `json:"followers"`
+}
+
+// NewLeaderStats generates a new LeaderStats with the given id as leader
+func NewLeaderStats(id string) *LeaderStats {
+	return &LeaderStats{
+		leaderStats: leaderStats{
+			Leader:    id,
+			Followers: make(map[string]*FollowerStats),
+		},
+	}
+}
+
+func (ls *LeaderStats) JSON() []byte {
+	ls.Lock()
+	stats := ls.leaderStats
+	ls.Unlock()
+	b, err := json.Marshal(stats)
+	// TODO(jonboulle): appropriate error handling?
+	if err != nil {
+		plog.Errorf("error marshalling leader stats (%v)", err)
+	}
+	return b
+}
+
+func (ls *LeaderStats) Follower(name string) *FollowerStats {
+	ls.Lock()
+	defer ls.Unlock()
+	fs, ok := ls.Followers[name]
+	if !ok {
+		fs = &FollowerStats{}
+		fs.Latency.Minimum = 1 << 63
+		ls.Followers[name] = fs
+	}
+	return fs
+}
+
+// FollowerStats encapsulates various statistics about a follower in an etcd cluster
+type FollowerStats struct {
+	Latency LatencyStats `json:"latency"`
+	Counts  CountsStats  `json:"counts"`
+
+	sync.Mutex
+}
+
+// LatencyStats encapsulates latency statistics.
+type LatencyStats struct {
+	Current           float64 `json:"current"`
+	Average           float64 `json:"average"`
+	averageSquare     float64
+	StandardDeviation float64 `json:"standardDeviation"`
+	Minimum           float64 `json:"minimum"`
+	Maximum           float64 `json:"maximum"`
+}
+
+// CountsStats encapsulates raft statistics.
+type CountsStats struct {
+	Fail    uint64 `json:"fail"`
+	Success uint64 `json:"success"`
+}
+
+// Succ updates the FollowerStats with a successful send
+func (fs *FollowerStats) Succ(d time.Duration) {
+	fs.Lock()
+	defer fs.Unlock()
+
+	total := float64(fs.Counts.Success) * fs.Latency.Average
+	totalSquare := float64(fs.Counts.Success) * fs.Latency.averageSquare
+
+	fs.Counts.Success++
+
+	fs.Latency.Current = float64(d) / (1000000.0)
+
+	if fs.Latency.Current > fs.Latency.Maximum {
+		fs.Latency.Maximum = fs.Latency.Current
+	}
+
+	if fs.Latency.Current < fs.Latency.Minimum {
+		fs.Latency.Minimum = fs.Latency.Current
+	}
+
+	fs.Latency.Average = (total + fs.Latency.Current) / float64(fs.Counts.Success)
+	fs.Latency.averageSquare = (totalSquare + fs.Latency.Current*fs.Latency.Current) / float64(fs.Counts.Success)
+
+	// sdv = sqrt(avg(x^2) - avg(x)^2)
+	fs.Latency.StandardDeviation = math.Sqrt(fs.Latency.averageSquare - fs.Latency.Average*fs.Latency.Average)
+}
+
+// Fail updates the FollowerStats with an unsuccessful send
+func (fs *FollowerStats) Fail() {
+	fs.Lock()
+	defer fs.Unlock()
+	fs.Counts.Fail++
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/queue.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/queue.go
new file mode 100644
index 0000000..2c3dff3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/queue.go
@@ -0,0 +1,110 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2stats
+
+import (
+	"sync"
+	"time"
+)
+
+const (
+	queueCapacity = 200
+)
+
+// RequestStats represent the stats for a request.
+// It encapsulates the sending time and the size of the request.
+type RequestStats struct {
+	SendingTime time.Time
+	Size        int
+}
+
+type statsQueue struct {
+	items        [queueCapacity]*RequestStats
+	size         int
+	front        int
+	back         int
+	totalReqSize int
+	rwl          sync.RWMutex
+}
+
+func (q *statsQueue) Len() int {
+	return q.size
+}
+
+func (q *statsQueue) ReqSize() int {
+	return q.totalReqSize
+}
+
+// FrontAndBack gets the front and back elements in the queue
+// We must grab front and back together with the protection of the lock
+func (q *statsQueue) frontAndBack() (*RequestStats, *RequestStats) {
+	q.rwl.RLock()
+	defer q.rwl.RUnlock()
+	if q.size != 0 {
+		return q.items[q.front], q.items[q.back]
+	}
+	return nil, nil
+}
+
+// Insert function insert a RequestStats into the queue and update the records
+func (q *statsQueue) Insert(p *RequestStats) {
+	q.rwl.Lock()
+	defer q.rwl.Unlock()
+
+	q.back = (q.back + 1) % queueCapacity
+
+	if q.size == queueCapacity { //dequeue
+		q.totalReqSize -= q.items[q.front].Size
+		q.front = (q.back + 1) % queueCapacity
+	} else {
+		q.size++
+	}
+
+	q.items[q.back] = p
+	q.totalReqSize += q.items[q.back].Size
+
+}
+
+// Rate function returns the package rate and byte rate
+func (q *statsQueue) Rate() (float64, float64) {
+	front, back := q.frontAndBack()
+
+	if front == nil || back == nil {
+		return 0, 0
+	}
+
+	if time.Since(back.SendingTime) > time.Second {
+		q.Clear()
+		return 0, 0
+	}
+
+	sampleDuration := back.SendingTime.Sub(front.SendingTime)
+
+	pr := float64(q.Len()) / float64(sampleDuration) * float64(time.Second)
+
+	br := float64(q.ReqSize()) / float64(sampleDuration) * float64(time.Second)
+
+	return pr, br
+}
+
+// Clear function clear up the statsQueue
+func (q *statsQueue) Clear() {
+	q.rwl.Lock()
+	defer q.rwl.Unlock()
+	q.back = -1
+	q.front = 0
+	q.size = 0
+	q.totalReqSize = 0
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/server.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/server.go
new file mode 100644
index 0000000..c4accc7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/server.go
@@ -0,0 +1,142 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2stats
+
+import (
+	"encoding/json"
+	"log"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/raft"
+)
+
+// ServerStats encapsulates various statistics about an EtcdServer and its
+// communication with other members of the cluster
+type ServerStats struct {
+	serverStats
+	sync.Mutex
+}
+
+func NewServerStats(name, id string) *ServerStats {
+	ss := &ServerStats{
+		serverStats: serverStats{
+			Name: name,
+			ID:   id,
+		},
+	}
+	now := time.Now()
+	ss.StartTime = now
+	ss.LeaderInfo.StartTime = now
+	ss.sendRateQueue = &statsQueue{back: -1}
+	ss.recvRateQueue = &statsQueue{back: -1}
+	return ss
+}
+
+type serverStats struct {
+	Name string `json:"name"`
+	// ID is the raft ID of the node.
+	// TODO(jonboulle): use ID instead of name?
+	ID        string         `json:"id"`
+	State     raft.StateType `json:"state"`
+	StartTime time.Time      `json:"startTime"`
+
+	LeaderInfo struct {
+		Name      string    `json:"leader"`
+		Uptime    string    `json:"uptime"`
+		StartTime time.Time `json:"startTime"`
+	} `json:"leaderInfo"`
+
+	RecvAppendRequestCnt uint64  `json:"recvAppendRequestCnt,"`
+	RecvingPkgRate       float64 `json:"recvPkgRate,omitempty"`
+	RecvingBandwidthRate float64 `json:"recvBandwidthRate,omitempty"`
+
+	SendAppendRequestCnt uint64  `json:"sendAppendRequestCnt"`
+	SendingPkgRate       float64 `json:"sendPkgRate,omitempty"`
+	SendingBandwidthRate float64 `json:"sendBandwidthRate,omitempty"`
+
+	sendRateQueue *statsQueue
+	recvRateQueue *statsQueue
+}
+
+func (ss *ServerStats) JSON() []byte {
+	ss.Lock()
+	stats := ss.serverStats
+	stats.SendingPkgRate, stats.SendingBandwidthRate = stats.sendRateQueue.Rate()
+	stats.RecvingPkgRate, stats.RecvingBandwidthRate = stats.recvRateQueue.Rate()
+	stats.LeaderInfo.Uptime = time.Since(stats.LeaderInfo.StartTime).String()
+	ss.Unlock()
+	b, err := json.Marshal(stats)
+	// TODO(jonboulle): appropriate error handling?
+	if err != nil {
+		log.Printf("stats: error marshalling server stats: %v", err)
+	}
+	return b
+}
+
+// RecvAppendReq updates the ServerStats in response to an AppendRequest
+// from the given leader being received
+func (ss *ServerStats) RecvAppendReq(leader string, reqSize int) {
+	ss.Lock()
+	defer ss.Unlock()
+
+	now := time.Now()
+
+	ss.State = raft.StateFollower
+	if leader != ss.LeaderInfo.Name {
+		ss.LeaderInfo.Name = leader
+		ss.LeaderInfo.StartTime = now
+	}
+
+	ss.recvRateQueue.Insert(
+		&RequestStats{
+			SendingTime: now,
+			Size:        reqSize,
+		},
+	)
+	ss.RecvAppendRequestCnt++
+}
+
+// SendAppendReq updates the ServerStats in response to an AppendRequest
+// being sent by this server
+func (ss *ServerStats) SendAppendReq(reqSize int) {
+	ss.Lock()
+	defer ss.Unlock()
+
+	ss.becomeLeader()
+
+	ss.sendRateQueue.Insert(
+		&RequestStats{
+			SendingTime: time.Now(),
+			Size:        reqSize,
+		},
+	)
+
+	ss.SendAppendRequestCnt++
+}
+
+func (ss *ServerStats) BecomeLeader() {
+	ss.Lock()
+	defer ss.Unlock()
+	ss.becomeLeader()
+}
+
+func (ss *ServerStats) becomeLeader() {
+	if ss.State != raft.StateLeader {
+		ss.State = raft.StateLeader
+		ss.LeaderInfo.Name = ss.ID
+		ss.LeaderInfo.StartTime = time.Now()
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/stats.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/stats.go
new file mode 100644
index 0000000..c50a200
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2stats/stats.go
@@ -0,0 +1,30 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2stats defines a standard interface for etcd cluster statistics.
+package v2stats
+
+import "github.com/coreos/pkg/capnslog"
+
+var plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/stats")
+
+type Stats interface {
+	// SelfStats returns the struct representing statistics of this server
+	SelfStats() []byte
+	// LeaderStats returns the statistics of all followers in the cluster
+	// if this server is leader. Otherwise, nil is returned.
+	LeaderStats() []byte
+	// StoreStats returns statistics of the store backing this EtcdServer
+	StoreStats() []byte
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/doc.go
new file mode 100644
index 0000000..1933e4c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/doc.go
@@ -0,0 +1,17 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2store defines etcd's in-memory key/value store in v2 API.
+// To be deprecated in favor of v3 storage.
+package v2store
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event.go
new file mode 100644
index 0000000..33e9017
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event.go
@@ -0,0 +1,71 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+const (
+	Get              = "get"
+	Create           = "create"
+	Set              = "set"
+	Update           = "update"
+	Delete           = "delete"
+	CompareAndSwap   = "compareAndSwap"
+	CompareAndDelete = "compareAndDelete"
+	Expire           = "expire"
+)
+
+type Event struct {
+	Action    string      `json:"action"`
+	Node      *NodeExtern `json:"node,omitempty"`
+	PrevNode  *NodeExtern `json:"prevNode,omitempty"`
+	EtcdIndex uint64      `json:"-"`
+	Refresh   bool        `json:"refresh,omitempty"`
+}
+
+func newEvent(action string, key string, modifiedIndex, createdIndex uint64) *Event {
+	n := &NodeExtern{
+		Key:           key,
+		ModifiedIndex: modifiedIndex,
+		CreatedIndex:  createdIndex,
+	}
+
+	return &Event{
+		Action: action,
+		Node:   n,
+	}
+}
+
+func (e *Event) IsCreated() bool {
+	if e.Action == Create {
+		return true
+	}
+	return e.Action == Set && e.PrevNode == nil
+}
+
+func (e *Event) Index() uint64 {
+	return e.Node.ModifiedIndex
+}
+
+func (e *Event) Clone() *Event {
+	return &Event{
+		Action:    e.Action,
+		EtcdIndex: e.EtcdIndex,
+		Node:      e.Node.Clone(),
+		PrevNode:  e.PrevNode.Clone(),
+	}
+}
+
+func (e *Event) SetRefresh() {
+	e.Refresh = true
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_history.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_history.go
new file mode 100644
index 0000000..e4a969f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_history.go
@@ -0,0 +1,129 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"fmt"
+	"path"
+	"strings"
+	"sync"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+)
+
+type EventHistory struct {
+	Queue      eventQueue
+	StartIndex uint64
+	LastIndex  uint64
+	rwl        sync.RWMutex
+}
+
+func newEventHistory(capacity int) *EventHistory {
+	return &EventHistory{
+		Queue: eventQueue{
+			Capacity: capacity,
+			Events:   make([]*Event, capacity),
+		},
+	}
+}
+
+// addEvent function adds event into the eventHistory
+func (eh *EventHistory) addEvent(e *Event) *Event {
+	eh.rwl.Lock()
+	defer eh.rwl.Unlock()
+
+	eh.Queue.insert(e)
+
+	eh.LastIndex = e.Index()
+
+	eh.StartIndex = eh.Queue.Events[eh.Queue.Front].Index()
+
+	return e
+}
+
+// scan enumerates events from the index history and stops at the first point
+// where the key matches.
+func (eh *EventHistory) scan(key string, recursive bool, index uint64) (*Event, *v2error.Error) {
+	eh.rwl.RLock()
+	defer eh.rwl.RUnlock()
+
+	// index should be after the event history's StartIndex
+	if index < eh.StartIndex {
+		return nil,
+			v2error.NewError(v2error.EcodeEventIndexCleared,
+				fmt.Sprintf("the requested history has been cleared [%v/%v]",
+					eh.StartIndex, index), 0)
+	}
+
+	// the index should come before the size of the queue minus the duplicate count
+	if index > eh.LastIndex { // future index
+		return nil, nil
+	}
+
+	offset := index - eh.StartIndex
+	i := (eh.Queue.Front + int(offset)) % eh.Queue.Capacity
+
+	for {
+		e := eh.Queue.Events[i]
+
+		if !e.Refresh {
+			ok := e.Node.Key == key
+
+			if recursive {
+				// add tailing slash
+				nkey := path.Clean(key)
+				if nkey[len(nkey)-1] != '/' {
+					nkey = nkey + "/"
+				}
+
+				ok = ok || strings.HasPrefix(e.Node.Key, nkey)
+			}
+
+			if (e.Action == Delete || e.Action == Expire) && e.PrevNode != nil && e.PrevNode.Dir {
+				ok = ok || strings.HasPrefix(key, e.PrevNode.Key)
+			}
+
+			if ok {
+				return e, nil
+			}
+		}
+
+		i = (i + 1) % eh.Queue.Capacity
+
+		if i == eh.Queue.Back {
+			return nil, nil
+		}
+	}
+}
+
+// clone will be protected by a stop-world lock
+// do not need to obtain internal lock
+func (eh *EventHistory) clone() *EventHistory {
+	clonedQueue := eventQueue{
+		Capacity: eh.Queue.Capacity,
+		Events:   make([]*Event, eh.Queue.Capacity),
+		Size:     eh.Queue.Size,
+		Front:    eh.Queue.Front,
+		Back:     eh.Queue.Back,
+	}
+
+	copy(clonedQueue.Events, eh.Queue.Events)
+	return &EventHistory{
+		StartIndex: eh.StartIndex,
+		Queue:      clonedQueue,
+		LastIndex:  eh.LastIndex,
+	}
+
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go
new file mode 100644
index 0000000..7ea03de
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/event_queue.go
@@ -0,0 +1,34 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+type eventQueue struct {
+	Events   []*Event
+	Size     int
+	Front    int
+	Back     int
+	Capacity int
+}
+
+func (eq *eventQueue) insert(e *Event) {
+	eq.Events[eq.Back] = e
+	eq.Back = (eq.Back + 1) % eq.Capacity
+
+	if eq.Size == eq.Capacity { //dequeue
+		eq.Front = (eq.Front + 1) % eq.Capacity
+	} else {
+		eq.Size++
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/metrics.go
new file mode 100644
index 0000000..5adea1e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/metrics.go
@@ -0,0 +1,130 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import "github.com/prometheus/client_golang/prometheus"
+
+// Set of raw Prometheus metrics.
+// Labels
+// * action = declared in event.go
+// * outcome = Outcome
+// Do not increment directly, use Report* methods.
+var (
+	readCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "reads_total",
+			Help:      "Total number of reads action by (get/getRecursive), local to this member.",
+		}, []string{"action"})
+
+	writeCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "writes_total",
+			Help:      "Total number of writes (e.g. set/compareAndDelete) seen by this member.",
+		}, []string{"action"})
+
+	readFailedCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "reads_failed_total",
+			Help:      "Failed read actions by (get/getRecursive), local to this member.",
+		}, []string{"action"})
+
+	writeFailedCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "writes_failed_total",
+			Help:      "Failed write actions (e.g. set/compareAndDelete), seen by this member.",
+		}, []string{"action"})
+
+	expireCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "expires_total",
+			Help:      "Total number of expired keys.",
+		})
+
+	watchRequests = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "watch_requests_total",
+			Help:      "Total number of incoming watch requests (new or reestablished).",
+		})
+
+	watcherCount = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "store",
+			Name:      "watchers",
+			Help:      "Count of currently active watchers.",
+		})
+)
+
+const (
+	GetRecursive = "getRecursive"
+)
+
+func init() {
+	if prometheus.Register(readCounter) != nil {
+		// Tests will try to double register since the tests use both
+		// store and store_test packages; ignore second attempts.
+		return
+	}
+	prometheus.MustRegister(writeCounter)
+	prometheus.MustRegister(expireCounter)
+	prometheus.MustRegister(watchRequests)
+	prometheus.MustRegister(watcherCount)
+}
+
+func reportReadSuccess(readAction string) {
+	readCounter.WithLabelValues(readAction).Inc()
+}
+
+func reportReadFailure(readAction string) {
+	readCounter.WithLabelValues(readAction).Inc()
+	readFailedCounter.WithLabelValues(readAction).Inc()
+}
+
+func reportWriteSuccess(writeAction string) {
+	writeCounter.WithLabelValues(writeAction).Inc()
+}
+
+func reportWriteFailure(writeAction string) {
+	writeCounter.WithLabelValues(writeAction).Inc()
+	writeFailedCounter.WithLabelValues(writeAction).Inc()
+}
+
+func reportExpiredKey() {
+	expireCounter.Inc()
+}
+
+func reportWatchRequest() {
+	watchRequests.Inc()
+}
+
+func reportWatcherAdded() {
+	watcherCount.Inc()
+}
+
+func reportWatcherRemoved() {
+	watcherCount.Dec()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node.go
new file mode 100644
index 0000000..38a6984
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node.go
@@ -0,0 +1,396 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"path"
+	"sort"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+
+	"github.com/jonboulle/clockwork"
+)
+
+// explanations of Compare function result
+const (
+	CompareMatch = iota
+	CompareIndexNotMatch
+	CompareValueNotMatch
+	CompareNotMatch
+)
+
+var Permanent time.Time
+
+// node is the basic element in the store system.
+// A key-value pair will have a string value
+// A directory will have a children map
+type node struct {
+	Path string
+
+	CreatedIndex  uint64
+	ModifiedIndex uint64
+
+	Parent *node `json:"-"` // should not encode this field! avoid circular dependency.
+
+	ExpireTime time.Time
+	Value      string           // for key-value pair
+	Children   map[string]*node // for directory
+
+	// A reference to the store this node is attached to.
+	store *store
+}
+
+// newKV creates a Key-Value pair
+func newKV(store *store, nodePath string, value string, createdIndex uint64, parent *node, expireTime time.Time) *node {
+	return &node{
+		Path:          nodePath,
+		CreatedIndex:  createdIndex,
+		ModifiedIndex: createdIndex,
+		Parent:        parent,
+		store:         store,
+		ExpireTime:    expireTime,
+		Value:         value,
+	}
+}
+
+// newDir creates a directory
+func newDir(store *store, nodePath string, createdIndex uint64, parent *node, expireTime time.Time) *node {
+	return &node{
+		Path:          nodePath,
+		CreatedIndex:  createdIndex,
+		ModifiedIndex: createdIndex,
+		Parent:        parent,
+		ExpireTime:    expireTime,
+		Children:      make(map[string]*node),
+		store:         store,
+	}
+}
+
+// IsHidden function checks if the node is a hidden node. A hidden node
+// will begin with '_'
+// A hidden node will not be shown via get command under a directory
+// For example if we have /foo/_hidden and /foo/notHidden, get "/foo"
+// will only return /foo/notHidden
+func (n *node) IsHidden() bool {
+	_, name := path.Split(n.Path)
+
+	return name[0] == '_'
+}
+
+// IsPermanent function checks if the node is a permanent one.
+func (n *node) IsPermanent() bool {
+	// we use a uninitialized time.Time to indicate the node is a
+	// permanent one.
+	// the uninitialized time.Time should equal zero.
+	return n.ExpireTime.IsZero()
+}
+
+// IsDir function checks whether the node is a directory.
+// If the node is a directory, the function will return true.
+// Otherwise the function will return false.
+func (n *node) IsDir() bool {
+	return n.Children != nil
+}
+
+// Read function gets the value of the node.
+// If the receiver node is not a key-value pair, a "Not A File" error will be returned.
+func (n *node) Read() (string, *v2error.Error) {
+	if n.IsDir() {
+		return "", v2error.NewError(v2error.EcodeNotFile, "", n.store.CurrentIndex)
+	}
+
+	return n.Value, nil
+}
+
+// Write function set the value of the node to the given value.
+// If the receiver node is a directory, a "Not A File" error will be returned.
+func (n *node) Write(value string, index uint64) *v2error.Error {
+	if n.IsDir() {
+		return v2error.NewError(v2error.EcodeNotFile, "", n.store.CurrentIndex)
+	}
+
+	n.Value = value
+	n.ModifiedIndex = index
+
+	return nil
+}
+
+func (n *node) expirationAndTTL(clock clockwork.Clock) (*time.Time, int64) {
+	if !n.IsPermanent() {
+		/* compute ttl as:
+		   ceiling( (expireTime - timeNow) / nanosecondsPerSecond )
+		   which ranges from 1..n
+		   rather than as:
+		   ( (expireTime - timeNow) / nanosecondsPerSecond ) + 1
+		   which ranges 1..n+1
+		*/
+		ttlN := n.ExpireTime.Sub(clock.Now())
+		ttl := ttlN / time.Second
+		if (ttlN % time.Second) > 0 {
+			ttl++
+		}
+		t := n.ExpireTime.UTC()
+		return &t, int64(ttl)
+	}
+	return nil, 0
+}
+
+// List function return a slice of nodes under the receiver node.
+// If the receiver node is not a directory, a "Not A Directory" error will be returned.
+func (n *node) List() ([]*node, *v2error.Error) {
+	if !n.IsDir() {
+		return nil, v2error.NewError(v2error.EcodeNotDir, "", n.store.CurrentIndex)
+	}
+
+	nodes := make([]*node, len(n.Children))
+
+	i := 0
+	for _, node := range n.Children {
+		nodes[i] = node
+		i++
+	}
+
+	return nodes, nil
+}
+
+// GetChild function returns the child node under the directory node.
+// On success, it returns the file node
+func (n *node) GetChild(name string) (*node, *v2error.Error) {
+	if !n.IsDir() {
+		return nil, v2error.NewError(v2error.EcodeNotDir, n.Path, n.store.CurrentIndex)
+	}
+
+	child, ok := n.Children[name]
+
+	if ok {
+		return child, nil
+	}
+
+	return nil, nil
+}
+
+// Add function adds a node to the receiver node.
+// If the receiver is not a directory, a "Not A Directory" error will be returned.
+// If there is an existing node with the same name under the directory, a "Already Exist"
+// error will be returned
+func (n *node) Add(child *node) *v2error.Error {
+	if !n.IsDir() {
+		return v2error.NewError(v2error.EcodeNotDir, "", n.store.CurrentIndex)
+	}
+
+	_, name := path.Split(child.Path)
+
+	if _, ok := n.Children[name]; ok {
+		return v2error.NewError(v2error.EcodeNodeExist, "", n.store.CurrentIndex)
+	}
+
+	n.Children[name] = child
+
+	return nil
+}
+
+// Remove function remove the node.
+func (n *node) Remove(dir, recursive bool, callback func(path string)) *v2error.Error {
+	if !n.IsDir() { // key-value pair
+		_, name := path.Split(n.Path)
+
+		// find its parent and remove the node from the map
+		if n.Parent != nil && n.Parent.Children[name] == n {
+			delete(n.Parent.Children, name)
+		}
+
+		if callback != nil {
+			callback(n.Path)
+		}
+
+		if !n.IsPermanent() {
+			n.store.ttlKeyHeap.remove(n)
+		}
+
+		return nil
+	}
+
+	if !dir {
+		// cannot delete a directory without dir set to true
+		return v2error.NewError(v2error.EcodeNotFile, n.Path, n.store.CurrentIndex)
+	}
+
+	if len(n.Children) != 0 && !recursive {
+		// cannot delete a directory if it is not empty and the operation
+		// is not recursive
+		return v2error.NewError(v2error.EcodeDirNotEmpty, n.Path, n.store.CurrentIndex)
+	}
+
+	for _, child := range n.Children { // delete all children
+		child.Remove(true, true, callback)
+	}
+
+	// delete self
+	_, name := path.Split(n.Path)
+	if n.Parent != nil && n.Parent.Children[name] == n {
+		delete(n.Parent.Children, name)
+
+		if callback != nil {
+			callback(n.Path)
+		}
+
+		if !n.IsPermanent() {
+			n.store.ttlKeyHeap.remove(n)
+		}
+	}
+
+	return nil
+}
+
+func (n *node) Repr(recursive, sorted bool, clock clockwork.Clock) *NodeExtern {
+	if n.IsDir() {
+		node := &NodeExtern{
+			Key:           n.Path,
+			Dir:           true,
+			ModifiedIndex: n.ModifiedIndex,
+			CreatedIndex:  n.CreatedIndex,
+		}
+		node.Expiration, node.TTL = n.expirationAndTTL(clock)
+
+		if !recursive {
+			return node
+		}
+
+		children, _ := n.List()
+		node.Nodes = make(NodeExterns, len(children))
+
+		// we do not use the index in the children slice directly
+		// we need to skip the hidden one
+		i := 0
+
+		for _, child := range children {
+
+			if child.IsHidden() { // get will not list hidden node
+				continue
+			}
+
+			node.Nodes[i] = child.Repr(recursive, sorted, clock)
+
+			i++
+		}
+
+		// eliminate hidden nodes
+		node.Nodes = node.Nodes[:i]
+		if sorted {
+			sort.Sort(node.Nodes)
+		}
+
+		return node
+	}
+
+	// since n.Value could be changed later, so we need to copy the value out
+	value := n.Value
+	node := &NodeExtern{
+		Key:           n.Path,
+		Value:         &value,
+		ModifiedIndex: n.ModifiedIndex,
+		CreatedIndex:  n.CreatedIndex,
+	}
+	node.Expiration, node.TTL = n.expirationAndTTL(clock)
+	return node
+}
+
+func (n *node) UpdateTTL(expireTime time.Time) {
+	if !n.IsPermanent() {
+		if expireTime.IsZero() {
+			// from ttl to permanent
+			n.ExpireTime = expireTime
+			// remove from ttl heap
+			n.store.ttlKeyHeap.remove(n)
+			return
+		}
+
+		// update ttl
+		n.ExpireTime = expireTime
+		// update ttl heap
+		n.store.ttlKeyHeap.update(n)
+		return
+	}
+
+	if expireTime.IsZero() {
+		return
+	}
+
+	// from permanent to ttl
+	n.ExpireTime = expireTime
+	// push into ttl heap
+	n.store.ttlKeyHeap.push(n)
+}
+
+// Compare function compares node index and value with provided ones.
+// second result value explains result and equals to one of Compare.. constants
+func (n *node) Compare(prevValue string, prevIndex uint64) (ok bool, which int) {
+	indexMatch := prevIndex == 0 || n.ModifiedIndex == prevIndex
+	valueMatch := prevValue == "" || n.Value == prevValue
+	ok = valueMatch && indexMatch
+	switch {
+	case valueMatch && indexMatch:
+		which = CompareMatch
+	case indexMatch && !valueMatch:
+		which = CompareValueNotMatch
+	case valueMatch && !indexMatch:
+		which = CompareIndexNotMatch
+	default:
+		which = CompareNotMatch
+	}
+	return ok, which
+}
+
+// Clone function clone the node recursively and return the new node.
+// If the node is a directory, it will clone all the content under this directory.
+// If the node is a key-value pair, it will clone the pair.
+func (n *node) Clone() *node {
+	if !n.IsDir() {
+		newkv := newKV(n.store, n.Path, n.Value, n.CreatedIndex, n.Parent, n.ExpireTime)
+		newkv.ModifiedIndex = n.ModifiedIndex
+		return newkv
+	}
+
+	clone := newDir(n.store, n.Path, n.CreatedIndex, n.Parent, n.ExpireTime)
+	clone.ModifiedIndex = n.ModifiedIndex
+
+	for key, child := range n.Children {
+		clone.Children[key] = child.Clone()
+	}
+
+	return clone
+}
+
+// recoverAndclean function help to do recovery.
+// Two things need to be done: 1. recovery structure; 2. delete expired nodes
+//
+// If the node is a directory, it will help recover children's parent pointer and recursively
+// call this function on its children.
+// We check the expire last since we need to recover the whole structure first and add all the
+// notifications into the event history.
+func (n *node) recoverAndclean() {
+	if n.IsDir() {
+		for _, child := range n.Children {
+			child.Parent = n
+			child.store = n.store
+			child.recoverAndclean()
+		}
+	}
+
+	if !n.ExpireTime.IsZero() {
+		n.store.ttlKeyHeap.push(n)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node_extern.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node_extern.go
new file mode 100644
index 0000000..b3bf5f3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/node_extern.go
@@ -0,0 +1,116 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"sort"
+	"time"
+
+	"github.com/jonboulle/clockwork"
+)
+
+// NodeExtern is the external representation of the
+// internal node with additional fields
+// PrevValue is the previous value of the node
+// TTL is time to live in second
+type NodeExtern struct {
+	Key           string      `json:"key,omitempty"`
+	Value         *string     `json:"value,omitempty"`
+	Dir           bool        `json:"dir,omitempty"`
+	Expiration    *time.Time  `json:"expiration,omitempty"`
+	TTL           int64       `json:"ttl,omitempty"`
+	Nodes         NodeExterns `json:"nodes,omitempty"`
+	ModifiedIndex uint64      `json:"modifiedIndex,omitempty"`
+	CreatedIndex  uint64      `json:"createdIndex,omitempty"`
+}
+
+func (eNode *NodeExtern) loadInternalNode(n *node, recursive, sorted bool, clock clockwork.Clock) {
+	if n.IsDir() { // node is a directory
+		eNode.Dir = true
+
+		children, _ := n.List()
+		eNode.Nodes = make(NodeExterns, len(children))
+
+		// we do not use the index in the children slice directly
+		// we need to skip the hidden one
+		i := 0
+
+		for _, child := range children {
+			if child.IsHidden() { // get will not return hidden nodes
+				continue
+			}
+
+			eNode.Nodes[i] = child.Repr(recursive, sorted, clock)
+			i++
+		}
+
+		// eliminate hidden nodes
+		eNode.Nodes = eNode.Nodes[:i]
+
+		if sorted {
+			sort.Sort(eNode.Nodes)
+		}
+
+	} else { // node is a file
+		value, _ := n.Read()
+		eNode.Value = &value
+	}
+
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(clock)
+}
+
+func (eNode *NodeExtern) Clone() *NodeExtern {
+	if eNode == nil {
+		return nil
+	}
+	nn := &NodeExtern{
+		Key:           eNode.Key,
+		Dir:           eNode.Dir,
+		TTL:           eNode.TTL,
+		ModifiedIndex: eNode.ModifiedIndex,
+		CreatedIndex:  eNode.CreatedIndex,
+	}
+	if eNode.Value != nil {
+		s := *eNode.Value
+		nn.Value = &s
+	}
+	if eNode.Expiration != nil {
+		t := *eNode.Expiration
+		nn.Expiration = &t
+	}
+	if eNode.Nodes != nil {
+		nn.Nodes = make(NodeExterns, len(eNode.Nodes))
+		for i, n := range eNode.Nodes {
+			nn.Nodes[i] = n.Clone()
+		}
+	}
+	return nn
+}
+
+type NodeExterns []*NodeExtern
+
+// interfaces for sorting
+
+func (ns NodeExterns) Len() int {
+	return len(ns)
+}
+
+func (ns NodeExterns) Less(i, j int) bool {
+	return ns[i].Key < ns[j].Key
+}
+
+func (ns NodeExterns) Swap(i, j int) {
+	ns[i], ns[j] = ns[j], ns[i]
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/stats.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/stats.go
new file mode 100644
index 0000000..45bc97f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/stats.go
@@ -0,0 +1,145 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"encoding/json"
+	"sync/atomic"
+)
+
+const (
+	SetSuccess = iota
+	SetFail
+	DeleteSuccess
+	DeleteFail
+	CreateSuccess
+	CreateFail
+	UpdateSuccess
+	UpdateFail
+	CompareAndSwapSuccess
+	CompareAndSwapFail
+	GetSuccess
+	GetFail
+	ExpireCount
+	CompareAndDeleteSuccess
+	CompareAndDeleteFail
+)
+
+type Stats struct {
+	// Number of get requests
+
+	GetSuccess uint64 `json:"getsSuccess"`
+	GetFail    uint64 `json:"getsFail"`
+
+	// Number of sets requests
+
+	SetSuccess uint64 `json:"setsSuccess"`
+	SetFail    uint64 `json:"setsFail"`
+
+	// Number of delete requests
+
+	DeleteSuccess uint64 `json:"deleteSuccess"`
+	DeleteFail    uint64 `json:"deleteFail"`
+
+	// Number of update requests
+
+	UpdateSuccess uint64 `json:"updateSuccess"`
+	UpdateFail    uint64 `json:"updateFail"`
+
+	// Number of create requests
+
+	CreateSuccess uint64 `json:"createSuccess"`
+	CreateFail    uint64 `json:"createFail"`
+
+	// Number of testAndSet requests
+
+	CompareAndSwapSuccess uint64 `json:"compareAndSwapSuccess"`
+	CompareAndSwapFail    uint64 `json:"compareAndSwapFail"`
+
+	// Number of compareAndDelete requests
+
+	CompareAndDeleteSuccess uint64 `json:"compareAndDeleteSuccess"`
+	CompareAndDeleteFail    uint64 `json:"compareAndDeleteFail"`
+
+	ExpireCount uint64 `json:"expireCount"`
+
+	Watchers uint64 `json:"watchers"`
+}
+
+func newStats() *Stats {
+	s := new(Stats)
+	return s
+}
+
+func (s *Stats) clone() *Stats {
+	return &Stats{
+		GetSuccess:              s.GetSuccess,
+		GetFail:                 s.GetFail,
+		SetSuccess:              s.SetSuccess,
+		SetFail:                 s.SetFail,
+		DeleteSuccess:           s.DeleteSuccess,
+		DeleteFail:              s.DeleteFail,
+		UpdateSuccess:           s.UpdateSuccess,
+		UpdateFail:              s.UpdateFail,
+		CreateSuccess:           s.CreateSuccess,
+		CreateFail:              s.CreateFail,
+		CompareAndSwapSuccess:   s.CompareAndSwapSuccess,
+		CompareAndSwapFail:      s.CompareAndSwapFail,
+		CompareAndDeleteSuccess: s.CompareAndDeleteSuccess,
+		CompareAndDeleteFail:    s.CompareAndDeleteFail,
+		ExpireCount:             s.ExpireCount,
+		Watchers:                s.Watchers,
+	}
+}
+
+func (s *Stats) toJson() []byte {
+	b, _ := json.Marshal(s)
+	return b
+}
+
+func (s *Stats) Inc(field int) {
+	switch field {
+	case SetSuccess:
+		atomic.AddUint64(&s.SetSuccess, 1)
+	case SetFail:
+		atomic.AddUint64(&s.SetFail, 1)
+	case CreateSuccess:
+		atomic.AddUint64(&s.CreateSuccess, 1)
+	case CreateFail:
+		atomic.AddUint64(&s.CreateFail, 1)
+	case DeleteSuccess:
+		atomic.AddUint64(&s.DeleteSuccess, 1)
+	case DeleteFail:
+		atomic.AddUint64(&s.DeleteFail, 1)
+	case GetSuccess:
+		atomic.AddUint64(&s.GetSuccess, 1)
+	case GetFail:
+		atomic.AddUint64(&s.GetFail, 1)
+	case UpdateSuccess:
+		atomic.AddUint64(&s.UpdateSuccess, 1)
+	case UpdateFail:
+		atomic.AddUint64(&s.UpdateFail, 1)
+	case CompareAndSwapSuccess:
+		atomic.AddUint64(&s.CompareAndSwapSuccess, 1)
+	case CompareAndSwapFail:
+		atomic.AddUint64(&s.CompareAndSwapFail, 1)
+	case CompareAndDeleteSuccess:
+		atomic.AddUint64(&s.CompareAndDeleteSuccess, 1)
+	case CompareAndDeleteFail:
+		atomic.AddUint64(&s.CompareAndDeleteFail, 1)
+	case ExpireCount:
+		atomic.AddUint64(&s.ExpireCount, 1)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/store.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/store.go
new file mode 100644
index 0000000..ce94043
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/store.go
@@ -0,0 +1,791 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"encoding/json"
+	"fmt"
+	"path"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/jonboulle/clockwork"
+)
+
+// The default version to set when the store is first initialized.
+const defaultVersion = 2
+
+var minExpireTime time.Time
+
+func init() {
+	minExpireTime, _ = time.Parse(time.RFC3339, "2000-01-01T00:00:00Z")
+}
+
+type Store interface {
+	Version() int
+	Index() uint64
+
+	Get(nodePath string, recursive, sorted bool) (*Event, error)
+	Set(nodePath string, dir bool, value string, expireOpts TTLOptionSet) (*Event, error)
+	Update(nodePath string, newValue string, expireOpts TTLOptionSet) (*Event, error)
+	Create(nodePath string, dir bool, value string, unique bool,
+		expireOpts TTLOptionSet) (*Event, error)
+	CompareAndSwap(nodePath string, prevValue string, prevIndex uint64,
+		value string, expireOpts TTLOptionSet) (*Event, error)
+	Delete(nodePath string, dir, recursive bool) (*Event, error)
+	CompareAndDelete(nodePath string, prevValue string, prevIndex uint64) (*Event, error)
+
+	Watch(prefix string, recursive, stream bool, sinceIndex uint64) (Watcher, error)
+
+	Save() ([]byte, error)
+	Recovery(state []byte) error
+
+	Clone() Store
+	SaveNoCopy() ([]byte, error)
+
+	JsonStats() []byte
+	DeleteExpiredKeys(cutoff time.Time)
+
+	HasTTLKeys() bool
+}
+
+type TTLOptionSet struct {
+	ExpireTime time.Time
+	Refresh    bool
+}
+
+type store struct {
+	Root           *node
+	WatcherHub     *watcherHub
+	CurrentIndex   uint64
+	Stats          *Stats
+	CurrentVersion int
+	ttlKeyHeap     *ttlKeyHeap  // need to recovery manually
+	worldLock      sync.RWMutex // stop the world lock
+	clock          clockwork.Clock
+	readonlySet    types.Set
+}
+
+// New creates a store where the given namespaces will be created as initial directories.
+func New(namespaces ...string) Store {
+	s := newStore(namespaces...)
+	s.clock = clockwork.NewRealClock()
+	return s
+}
+
+func newStore(namespaces ...string) *store {
+	s := new(store)
+	s.CurrentVersion = defaultVersion
+	s.Root = newDir(s, "/", s.CurrentIndex, nil, Permanent)
+	for _, namespace := range namespaces {
+		s.Root.Add(newDir(s, namespace, s.CurrentIndex, s.Root, Permanent))
+	}
+	s.Stats = newStats()
+	s.WatcherHub = newWatchHub(1000)
+	s.ttlKeyHeap = newTtlKeyHeap()
+	s.readonlySet = types.NewUnsafeSet(append(namespaces, "/")...)
+	return s
+}
+
+// Version retrieves current version of the store.
+func (s *store) Version() int {
+	return s.CurrentVersion
+}
+
+// Index retrieves the current index of the store.
+func (s *store) Index() uint64 {
+	s.worldLock.RLock()
+	defer s.worldLock.RUnlock()
+	return s.CurrentIndex
+}
+
+// Get returns a get event.
+// If recursive is true, it will return all the content under the node path.
+// If sorted is true, it will sort the content by keys.
+func (s *store) Get(nodePath string, recursive, sorted bool) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.RLock()
+	defer s.worldLock.RUnlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(GetSuccess)
+			if recursive {
+				reportReadSuccess(GetRecursive)
+			} else {
+				reportReadSuccess(Get)
+			}
+			return
+		}
+
+		s.Stats.Inc(GetFail)
+		if recursive {
+			reportReadFailure(GetRecursive)
+		} else {
+			reportReadFailure(Get)
+		}
+	}()
+
+	n, err := s.internalGet(nodePath)
+	if err != nil {
+		return nil, err
+	}
+
+	e := newEvent(Get, nodePath, n.ModifiedIndex, n.CreatedIndex)
+	e.EtcdIndex = s.CurrentIndex
+	e.Node.loadInternalNode(n, recursive, sorted, s.clock)
+
+	return e, nil
+}
+
+// Create creates the node at nodePath. Create will help to create intermediate directories with no ttl.
+// If the node has already existed, create will fail.
+// If any node on the path is a file, create will fail.
+func (s *store) Create(nodePath string, dir bool, value string, unique bool, expireOpts TTLOptionSet) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(CreateSuccess)
+			reportWriteSuccess(Create)
+			return
+		}
+
+		s.Stats.Inc(CreateFail)
+		reportWriteFailure(Create)
+	}()
+
+	e, err := s.internalCreate(nodePath, dir, value, unique, false, expireOpts.ExpireTime, Create)
+	if err != nil {
+		return nil, err
+	}
+
+	e.EtcdIndex = s.CurrentIndex
+	s.WatcherHub.notify(e)
+
+	return e, nil
+}
+
+// Set creates or replace the node at nodePath.
+func (s *store) Set(nodePath string, dir bool, value string, expireOpts TTLOptionSet) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(SetSuccess)
+			reportWriteSuccess(Set)
+			return
+		}
+
+		s.Stats.Inc(SetFail)
+		reportWriteFailure(Set)
+	}()
+
+	// Get prevNode value
+	n, getErr := s.internalGet(nodePath)
+	if getErr != nil && getErr.ErrorCode != v2error.EcodeKeyNotFound {
+		err = getErr
+		return nil, err
+	}
+
+	if expireOpts.Refresh {
+		if getErr != nil {
+			err = getErr
+			return nil, err
+		}
+		value = n.Value
+	}
+
+	// Set new value
+	e, err := s.internalCreate(nodePath, dir, value, false, true, expireOpts.ExpireTime, Set)
+	if err != nil {
+		return nil, err
+	}
+	e.EtcdIndex = s.CurrentIndex
+
+	// Put prevNode into event
+	if getErr == nil {
+		prev := newEvent(Get, nodePath, n.ModifiedIndex, n.CreatedIndex)
+		prev.Node.loadInternalNode(n, false, false, s.clock)
+		e.PrevNode = prev.Node
+	}
+
+	if !expireOpts.Refresh {
+		s.WatcherHub.notify(e)
+	} else {
+		e.SetRefresh()
+		s.WatcherHub.add(e)
+	}
+
+	return e, nil
+}
+
+// returns user-readable cause of failed comparison
+func getCompareFailCause(n *node, which int, prevValue string, prevIndex uint64) string {
+	switch which {
+	case CompareIndexNotMatch:
+		return fmt.Sprintf("[%v != %v]", prevIndex, n.ModifiedIndex)
+	case CompareValueNotMatch:
+		return fmt.Sprintf("[%v != %v]", prevValue, n.Value)
+	default:
+		return fmt.Sprintf("[%v != %v] [%v != %v]", prevValue, n.Value, prevIndex, n.ModifiedIndex)
+	}
+}
+
+func (s *store) CompareAndSwap(nodePath string, prevValue string, prevIndex uint64,
+	value string, expireOpts TTLOptionSet) (*Event, error) {
+
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(CompareAndSwapSuccess)
+			reportWriteSuccess(CompareAndSwap)
+			return
+		}
+
+		s.Stats.Inc(CompareAndSwapFail)
+		reportWriteFailure(CompareAndSwap)
+	}()
+
+	nodePath = path.Clean(path.Join("/", nodePath))
+	// we do not allow the user to change "/"
+	if s.readonlySet.Contains(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, "/", s.CurrentIndex)
+	}
+
+	n, err := s.internalGet(nodePath)
+	if err != nil {
+		return nil, err
+	}
+	if n.IsDir() { // can only compare and swap file
+		err = v2error.NewError(v2error.EcodeNotFile, nodePath, s.CurrentIndex)
+		return nil, err
+	}
+
+	// If both of the prevValue and prevIndex are given, we will test both of them.
+	// Command will be executed, only if both of the tests are successful.
+	if ok, which := n.Compare(prevValue, prevIndex); !ok {
+		cause := getCompareFailCause(n, which, prevValue, prevIndex)
+		err = v2error.NewError(v2error.EcodeTestFailed, cause, s.CurrentIndex)
+		return nil, err
+	}
+
+	if expireOpts.Refresh {
+		value = n.Value
+	}
+
+	// update etcd index
+	s.CurrentIndex++
+
+	e := newEvent(CompareAndSwap, nodePath, s.CurrentIndex, n.CreatedIndex)
+	e.EtcdIndex = s.CurrentIndex
+	e.PrevNode = n.Repr(false, false, s.clock)
+	eNode := e.Node
+
+	// if test succeed, write the value
+	n.Write(value, s.CurrentIndex)
+	n.UpdateTTL(expireOpts.ExpireTime)
+
+	// copy the value for safety
+	valueCopy := value
+	eNode.Value = &valueCopy
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
+
+	if !expireOpts.Refresh {
+		s.WatcherHub.notify(e)
+	} else {
+		e.SetRefresh()
+		s.WatcherHub.add(e)
+	}
+
+	return e, nil
+}
+
+// Delete deletes the node at the given path.
+// If the node is a directory, recursive must be true to delete it.
+func (s *store) Delete(nodePath string, dir, recursive bool) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(DeleteSuccess)
+			reportWriteSuccess(Delete)
+			return
+		}
+
+		s.Stats.Inc(DeleteFail)
+		reportWriteFailure(Delete)
+	}()
+
+	nodePath = path.Clean(path.Join("/", nodePath))
+	// we do not allow the user to change "/"
+	if s.readonlySet.Contains(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, "/", s.CurrentIndex)
+	}
+
+	// recursive implies dir
+	if recursive {
+		dir = true
+	}
+
+	n, err := s.internalGet(nodePath)
+	if err != nil { // if the node does not exist, return error
+		return nil, err
+	}
+
+	nextIndex := s.CurrentIndex + 1
+	e := newEvent(Delete, nodePath, nextIndex, n.CreatedIndex)
+	e.EtcdIndex = nextIndex
+	e.PrevNode = n.Repr(false, false, s.clock)
+	eNode := e.Node
+
+	if n.IsDir() {
+		eNode.Dir = true
+	}
+
+	callback := func(path string) { // notify function
+		// notify the watchers with deleted set true
+		s.WatcherHub.notifyWatchers(e, path, true)
+	}
+
+	err = n.Remove(dir, recursive, callback)
+	if err != nil {
+		return nil, err
+	}
+
+	// update etcd index
+	s.CurrentIndex++
+
+	s.WatcherHub.notify(e)
+
+	return e, nil
+}
+
+func (s *store) CompareAndDelete(nodePath string, prevValue string, prevIndex uint64) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(CompareAndDeleteSuccess)
+			reportWriteSuccess(CompareAndDelete)
+			return
+		}
+
+		s.Stats.Inc(CompareAndDeleteFail)
+		reportWriteFailure(CompareAndDelete)
+	}()
+
+	nodePath = path.Clean(path.Join("/", nodePath))
+
+	n, err := s.internalGet(nodePath)
+	if err != nil { // if the node does not exist, return error
+		return nil, err
+	}
+	if n.IsDir() { // can only compare and delete file
+		return nil, v2error.NewError(v2error.EcodeNotFile, nodePath, s.CurrentIndex)
+	}
+
+	// If both of the prevValue and prevIndex are given, we will test both of them.
+	// Command will be executed, only if both of the tests are successful.
+	if ok, which := n.Compare(prevValue, prevIndex); !ok {
+		cause := getCompareFailCause(n, which, prevValue, prevIndex)
+		return nil, v2error.NewError(v2error.EcodeTestFailed, cause, s.CurrentIndex)
+	}
+
+	// update etcd index
+	s.CurrentIndex++
+
+	e := newEvent(CompareAndDelete, nodePath, s.CurrentIndex, n.CreatedIndex)
+	e.EtcdIndex = s.CurrentIndex
+	e.PrevNode = n.Repr(false, false, s.clock)
+
+	callback := func(path string) { // notify function
+		// notify the watchers with deleted set true
+		s.WatcherHub.notifyWatchers(e, path, true)
+	}
+
+	err = n.Remove(false, false, callback)
+	if err != nil {
+		return nil, err
+	}
+
+	s.WatcherHub.notify(e)
+
+	return e, nil
+}
+
+func (s *store) Watch(key string, recursive, stream bool, sinceIndex uint64) (Watcher, error) {
+	s.worldLock.RLock()
+	defer s.worldLock.RUnlock()
+
+	key = path.Clean(path.Join("/", key))
+	if sinceIndex == 0 {
+		sinceIndex = s.CurrentIndex + 1
+	}
+	// WatcherHub does not know about the current index, so we need to pass it in
+	w, err := s.WatcherHub.watch(key, recursive, stream, sinceIndex, s.CurrentIndex)
+	if err != nil {
+		return nil, err
+	}
+
+	return w, nil
+}
+
+// walk walks all the nodePath and apply the walkFunc on each directory
+func (s *store) walk(nodePath string, walkFunc func(prev *node, component string) (*node, *v2error.Error)) (*node, *v2error.Error) {
+	components := strings.Split(nodePath, "/")
+
+	curr := s.Root
+	var err *v2error.Error
+
+	for i := 1; i < len(components); i++ {
+		if len(components[i]) == 0 { // ignore empty string
+			return curr, nil
+		}
+
+		curr, err = walkFunc(curr, components[i])
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return curr, nil
+}
+
+// Update updates the value/ttl of the node.
+// If the node is a file, the value and the ttl can be updated.
+// If the node is a directory, only the ttl can be updated.
+func (s *store) Update(nodePath string, newValue string, expireOpts TTLOptionSet) (*Event, error) {
+	var err *v2error.Error
+
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	defer func() {
+		if err == nil {
+			s.Stats.Inc(UpdateSuccess)
+			reportWriteSuccess(Update)
+			return
+		}
+
+		s.Stats.Inc(UpdateFail)
+		reportWriteFailure(Update)
+	}()
+
+	nodePath = path.Clean(path.Join("/", nodePath))
+	// we do not allow the user to change "/"
+	if s.readonlySet.Contains(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, "/", s.CurrentIndex)
+	}
+
+	currIndex, nextIndex := s.CurrentIndex, s.CurrentIndex+1
+
+	n, err := s.internalGet(nodePath)
+	if err != nil { // if the node does not exist, return error
+		return nil, err
+	}
+	if n.IsDir() && len(newValue) != 0 {
+		// if the node is a directory, we cannot update value to non-empty
+		return nil, v2error.NewError(v2error.EcodeNotFile, nodePath, currIndex)
+	}
+
+	if expireOpts.Refresh {
+		newValue = n.Value
+	}
+
+	e := newEvent(Update, nodePath, nextIndex, n.CreatedIndex)
+	e.EtcdIndex = nextIndex
+	e.PrevNode = n.Repr(false, false, s.clock)
+	eNode := e.Node
+
+	n.Write(newValue, nextIndex)
+
+	if n.IsDir() {
+		eNode.Dir = true
+	} else {
+		// copy the value for safety
+		newValueCopy := newValue
+		eNode.Value = &newValueCopy
+	}
+
+	// update ttl
+	n.UpdateTTL(expireOpts.ExpireTime)
+
+	eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
+
+	if !expireOpts.Refresh {
+		s.WatcherHub.notify(e)
+	} else {
+		e.SetRefresh()
+		s.WatcherHub.add(e)
+	}
+
+	s.CurrentIndex = nextIndex
+
+	return e, nil
+}
+
+func (s *store) internalCreate(nodePath string, dir bool, value string, unique, replace bool,
+	expireTime time.Time, action string) (*Event, *v2error.Error) {
+
+	currIndex, nextIndex := s.CurrentIndex, s.CurrentIndex+1
+
+	if unique { // append unique item under the node path
+		nodePath += "/" + fmt.Sprintf("%020s", strconv.FormatUint(nextIndex, 10))
+	}
+
+	nodePath = path.Clean(path.Join("/", nodePath))
+
+	// we do not allow the user to change "/"
+	if s.readonlySet.Contains(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, "/", currIndex)
+	}
+
+	// Assume expire times that are way in the past are
+	// This can occur when the time is serialized to JS
+	if expireTime.Before(minExpireTime) {
+		expireTime = Permanent
+	}
+
+	dirName, nodeName := path.Split(nodePath)
+
+	// walk through the nodePath, create dirs and get the last directory node
+	d, err := s.walk(dirName, s.checkDir)
+
+	if err != nil {
+		s.Stats.Inc(SetFail)
+		reportWriteFailure(action)
+		err.Index = currIndex
+		return nil, err
+	}
+
+	e := newEvent(action, nodePath, nextIndex, nextIndex)
+	eNode := e.Node
+
+	n, _ := d.GetChild(nodeName)
+
+	// force will try to replace an existing file
+	if n != nil {
+		if replace {
+			if n.IsDir() {
+				return nil, v2error.NewError(v2error.EcodeNotFile, nodePath, currIndex)
+			}
+			e.PrevNode = n.Repr(false, false, s.clock)
+
+			n.Remove(false, false, nil)
+		} else {
+			return nil, v2error.NewError(v2error.EcodeNodeExist, nodePath, currIndex)
+		}
+	}
+
+	if !dir { // create file
+		// copy the value for safety
+		valueCopy := value
+		eNode.Value = &valueCopy
+
+		n = newKV(s, nodePath, value, nextIndex, d, expireTime)
+
+	} else { // create directory
+		eNode.Dir = true
+
+		n = newDir(s, nodePath, nextIndex, d, expireTime)
+	}
+
+	// we are sure d is a directory and does not have the children with name n.Name
+	d.Add(n)
+
+	// node with TTL
+	if !n.IsPermanent() {
+		s.ttlKeyHeap.push(n)
+
+		eNode.Expiration, eNode.TTL = n.expirationAndTTL(s.clock)
+	}
+
+	s.CurrentIndex = nextIndex
+
+	return e, nil
+}
+
+// InternalGet gets the node of the given nodePath.
+func (s *store) internalGet(nodePath string) (*node, *v2error.Error) {
+	nodePath = path.Clean(path.Join("/", nodePath))
+
+	walkFunc := func(parent *node, name string) (*node, *v2error.Error) {
+
+		if !parent.IsDir() {
+			err := v2error.NewError(v2error.EcodeNotDir, parent.Path, s.CurrentIndex)
+			return nil, err
+		}
+
+		child, ok := parent.Children[name]
+		if ok {
+			return child, nil
+		}
+
+		return nil, v2error.NewError(v2error.EcodeKeyNotFound, path.Join(parent.Path, name), s.CurrentIndex)
+	}
+
+	f, err := s.walk(nodePath, walkFunc)
+
+	if err != nil {
+		return nil, err
+	}
+	return f, nil
+}
+
+// DeleteExpiredKeys will delete all expired keys
+func (s *store) DeleteExpiredKeys(cutoff time.Time) {
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+
+	for {
+		node := s.ttlKeyHeap.top()
+		if node == nil || node.ExpireTime.After(cutoff) {
+			break
+		}
+
+		s.CurrentIndex++
+		e := newEvent(Expire, node.Path, s.CurrentIndex, node.CreatedIndex)
+		e.EtcdIndex = s.CurrentIndex
+		e.PrevNode = node.Repr(false, false, s.clock)
+		if node.IsDir() {
+			e.Node.Dir = true
+		}
+
+		callback := func(path string) { // notify function
+			// notify the watchers with deleted set true
+			s.WatcherHub.notifyWatchers(e, path, true)
+		}
+
+		s.ttlKeyHeap.pop()
+		node.Remove(true, true, callback)
+
+		reportExpiredKey()
+		s.Stats.Inc(ExpireCount)
+
+		s.WatcherHub.notify(e)
+	}
+
+}
+
+// checkDir will check whether the component is a directory under parent node.
+// If it is a directory, this function will return the pointer to that node.
+// If it does not exist, this function will create a new directory and return the pointer to that node.
+// If it is a file, this function will return error.
+func (s *store) checkDir(parent *node, dirName string) (*node, *v2error.Error) {
+	node, ok := parent.Children[dirName]
+
+	if ok {
+		if node.IsDir() {
+			return node, nil
+		}
+
+		return nil, v2error.NewError(v2error.EcodeNotDir, node.Path, s.CurrentIndex)
+	}
+
+	n := newDir(s, path.Join(parent.Path, dirName), s.CurrentIndex+1, parent, Permanent)
+
+	parent.Children[dirName] = n
+
+	return n, nil
+}
+
+// Save saves the static state of the store system.
+// It will not be able to save the state of watchers.
+// It will not save the parent field of the node. Or there will
+// be cyclic dependencies issue for the json package.
+func (s *store) Save() ([]byte, error) {
+	b, err := json.Marshal(s.Clone())
+	if err != nil {
+		return nil, err
+	}
+
+	return b, nil
+}
+
+func (s *store) SaveNoCopy() ([]byte, error) {
+	b, err := json.Marshal(s)
+	if err != nil {
+		return nil, err
+	}
+
+	return b, nil
+}
+
+func (s *store) Clone() Store {
+	s.worldLock.Lock()
+
+	clonedStore := newStore()
+	clonedStore.CurrentIndex = s.CurrentIndex
+	clonedStore.Root = s.Root.Clone()
+	clonedStore.WatcherHub = s.WatcherHub.clone()
+	clonedStore.Stats = s.Stats.clone()
+	clonedStore.CurrentVersion = s.CurrentVersion
+
+	s.worldLock.Unlock()
+	return clonedStore
+}
+
+// Recovery recovers the store system from a static state
+// It needs to recover the parent field of the nodes.
+// It needs to delete the expired nodes since the saved time and also
+// needs to create monitoring go routines.
+func (s *store) Recovery(state []byte) error {
+	s.worldLock.Lock()
+	defer s.worldLock.Unlock()
+	err := json.Unmarshal(state, s)
+
+	if err != nil {
+		return err
+	}
+
+	s.ttlKeyHeap = newTtlKeyHeap()
+
+	s.Root.recoverAndclean()
+	return nil
+}
+
+func (s *store) JsonStats() []byte {
+	s.Stats.Watchers = uint64(s.WatcherHub.count)
+	return s.Stats.toJson()
+}
+
+func (s *store) HasTTLKeys() bool {
+	s.worldLock.RLock()
+	defer s.worldLock.RUnlock()
+	return s.ttlKeyHeap.Len() != 0
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/ttl_key_heap.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/ttl_key_heap.go
new file mode 100644
index 0000000..477d2b9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/ttl_key_heap.go
@@ -0,0 +1,97 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import "container/heap"
+
+// An TTLKeyHeap is a min-heap of TTLKeys order by expiration time
+type ttlKeyHeap struct {
+	array  []*node
+	keyMap map[*node]int
+}
+
+func newTtlKeyHeap() *ttlKeyHeap {
+	h := &ttlKeyHeap{keyMap: make(map[*node]int)}
+	heap.Init(h)
+	return h
+}
+
+func (h ttlKeyHeap) Len() int {
+	return len(h.array)
+}
+
+func (h ttlKeyHeap) Less(i, j int) bool {
+	return h.array[i].ExpireTime.Before(h.array[j].ExpireTime)
+}
+
+func (h ttlKeyHeap) Swap(i, j int) {
+	// swap node
+	h.array[i], h.array[j] = h.array[j], h.array[i]
+
+	// update map
+	h.keyMap[h.array[i]] = i
+	h.keyMap[h.array[j]] = j
+}
+
+func (h *ttlKeyHeap) Push(x interface{}) {
+	n, _ := x.(*node)
+	h.keyMap[n] = len(h.array)
+	h.array = append(h.array, n)
+}
+
+func (h *ttlKeyHeap) Pop() interface{} {
+	old := h.array
+	n := len(old)
+	x := old[n-1]
+	// Set slice element to nil, so GC can recycle the node.
+	// This is due to golang GC doesn't support partial recycling:
+	// https://github.com/golang/go/issues/9618
+	old[n-1] = nil
+	h.array = old[0 : n-1]
+	delete(h.keyMap, x)
+	return x
+}
+
+func (h *ttlKeyHeap) top() *node {
+	if h.Len() != 0 {
+		return h.array[0]
+	}
+	return nil
+}
+
+func (h *ttlKeyHeap) pop() *node {
+	x := heap.Pop(h)
+	n, _ := x.(*node)
+	return n
+}
+
+func (h *ttlKeyHeap) push(x interface{}) {
+	heap.Push(h, x)
+}
+
+func (h *ttlKeyHeap) update(n *node) {
+	index, ok := h.keyMap[n]
+	if ok {
+		heap.Remove(h, index)
+		heap.Push(h, n)
+	}
+}
+
+func (h *ttlKeyHeap) remove(n *node) {
+	index, ok := h.keyMap[n]
+	if ok {
+		heap.Remove(h, index)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher.go
new file mode 100644
index 0000000..4b1e846
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher.go
@@ -0,0 +1,95 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+type Watcher interface {
+	EventChan() chan *Event
+	StartIndex() uint64 // The EtcdIndex at which the Watcher was created
+	Remove()
+}
+
+type watcher struct {
+	eventChan  chan *Event
+	stream     bool
+	recursive  bool
+	sinceIndex uint64
+	startIndex uint64
+	hub        *watcherHub
+	removed    bool
+	remove     func()
+}
+
+func (w *watcher) EventChan() chan *Event {
+	return w.eventChan
+}
+
+func (w *watcher) StartIndex() uint64 {
+	return w.startIndex
+}
+
+// notify function notifies the watcher. If the watcher interests in the given path,
+// the function will return true.
+func (w *watcher) notify(e *Event, originalPath bool, deleted bool) bool {
+	// watcher is interested the path in three cases and under one condition
+	// the condition is that the event happens after the watcher's sinceIndex
+
+	// 1. the path at which the event happens is the path the watcher is watching at.
+	// For example if the watcher is watching at "/foo" and the event happens at "/foo",
+	// the watcher must be interested in that event.
+
+	// 2. the watcher is a recursive watcher, it interests in the event happens after
+	// its watching path. For example if watcher A watches at "/foo" and it is a recursive
+	// one, it will interest in the event happens at "/foo/bar".
+
+	// 3. when we delete a directory, we need to force notify all the watchers who watches
+	// at the file we need to delete.
+	// For example a watcher is watching at "/foo/bar". And we deletes "/foo". The watcher
+	// should get notified even if "/foo" is not the path it is watching.
+	if (w.recursive || originalPath || deleted) && e.Index() >= w.sinceIndex {
+		// We cannot block here if the eventChan capacity is full, otherwise
+		// etcd will hang. eventChan capacity is full when the rate of
+		// notifications are higher than our send rate.
+		// If this happens, we close the channel.
+		select {
+		case w.eventChan <- e:
+		default:
+			// We have missed a notification. Remove the watcher.
+			// Removing the watcher also closes the eventChan.
+			w.remove()
+		}
+		return true
+	}
+	return false
+}
+
+// Remove removes the watcher from watcherHub
+// The actual remove function is guaranteed to only be executed once
+func (w *watcher) Remove() {
+	w.hub.mutex.Lock()
+	defer w.hub.mutex.Unlock()
+
+	close(w.eventChan)
+	if w.remove != nil {
+		w.remove()
+	}
+}
+
+// nopWatcher is a watcher that receives nothing, always blocking.
+type nopWatcher struct{}
+
+func NewNopWatcher() Watcher                 { return &nopWatcher{} }
+func (w *nopWatcher) EventChan() chan *Event { return nil }
+func (w *nopWatcher) StartIndex() uint64     { return 0 }
+func (w *nopWatcher) Remove()                {}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher_hub.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher_hub.go
new file mode 100644
index 0000000..a452e7e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2store/watcher_hub.go
@@ -0,0 +1,200 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2store
+
+import (
+	"container/list"
+	"path"
+	"strings"
+	"sync"
+	"sync/atomic"
+
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+)
+
+// A watcherHub contains all subscribed watchers
+// watchers is a map with watched path as key and watcher as value
+// EventHistory keeps the old events for watcherHub. It is used to help
+// watcher to get a continuous event history. Or a watcher might miss the
+// event happens between the end of the first watch command and the start
+// of the second command.
+type watcherHub struct {
+	// count must be the first element to keep 64-bit alignment for atomic
+	// access
+
+	count int64 // current number of watchers.
+
+	mutex        sync.Mutex
+	watchers     map[string]*list.List
+	EventHistory *EventHistory
+}
+
+// newWatchHub creates a watcherHub. The capacity determines how many events we will
+// keep in the eventHistory.
+// Typically, we only need to keep a small size of history[smaller than 20K].
+// Ideally, it should smaller than 20K/s[max throughput] * 2 * 50ms[RTT] = 2000
+func newWatchHub(capacity int) *watcherHub {
+	return &watcherHub{
+		watchers:     make(map[string]*list.List),
+		EventHistory: newEventHistory(capacity),
+	}
+}
+
+// Watch function returns a Watcher.
+// If recursive is true, the first change after index under key will be sent to the event channel of the watcher.
+// If recursive is false, the first change after index at key will be sent to the event channel of the watcher.
+// If index is zero, watch will start from the current index + 1.
+func (wh *watcherHub) watch(key string, recursive, stream bool, index, storeIndex uint64) (Watcher, *v2error.Error) {
+	reportWatchRequest()
+	event, err := wh.EventHistory.scan(key, recursive, index)
+
+	if err != nil {
+		err.Index = storeIndex
+		return nil, err
+	}
+
+	w := &watcher{
+		eventChan:  make(chan *Event, 100), // use a buffered channel
+		recursive:  recursive,
+		stream:     stream,
+		sinceIndex: index,
+		startIndex: storeIndex,
+		hub:        wh,
+	}
+
+	wh.mutex.Lock()
+	defer wh.mutex.Unlock()
+	// If the event exists in the known history, append the EtcdIndex and return immediately
+	if event != nil {
+		ne := event.Clone()
+		ne.EtcdIndex = storeIndex
+		w.eventChan <- ne
+		return w, nil
+	}
+
+	l, ok := wh.watchers[key]
+
+	var elem *list.Element
+
+	if ok { // add the new watcher to the back of the list
+		elem = l.PushBack(w)
+	} else { // create a new list and add the new watcher
+		l = list.New()
+		elem = l.PushBack(w)
+		wh.watchers[key] = l
+	}
+
+	w.remove = func() {
+		if w.removed { // avoid removing it twice
+			return
+		}
+		w.removed = true
+		l.Remove(elem)
+		atomic.AddInt64(&wh.count, -1)
+		reportWatcherRemoved()
+		if l.Len() == 0 {
+			delete(wh.watchers, key)
+		}
+	}
+
+	atomic.AddInt64(&wh.count, 1)
+	reportWatcherAdded()
+
+	return w, nil
+}
+
+func (wh *watcherHub) add(e *Event) {
+	wh.EventHistory.addEvent(e)
+}
+
+// notify function accepts an event and notify to the watchers.
+func (wh *watcherHub) notify(e *Event) {
+	e = wh.EventHistory.addEvent(e) // add event into the eventHistory
+
+	segments := strings.Split(e.Node.Key, "/")
+
+	currPath := "/"
+
+	// walk through all the segments of the path and notify the watchers
+	// if the path is "/foo/bar", it will notify watchers with path "/",
+	// "/foo" and "/foo/bar"
+
+	for _, segment := range segments {
+		currPath = path.Join(currPath, segment)
+		// notify the watchers who interests in the changes of current path
+		wh.notifyWatchers(e, currPath, false)
+	}
+}
+
+func (wh *watcherHub) notifyWatchers(e *Event, nodePath string, deleted bool) {
+	wh.mutex.Lock()
+	defer wh.mutex.Unlock()
+
+	l, ok := wh.watchers[nodePath]
+	if ok {
+		curr := l.Front()
+
+		for curr != nil {
+			next := curr.Next() // save reference to the next one in the list
+
+			w, _ := curr.Value.(*watcher)
+
+			originalPath := e.Node.Key == nodePath
+			if (originalPath || !isHidden(nodePath, e.Node.Key)) && w.notify(e, originalPath, deleted) {
+				if !w.stream { // do not remove the stream watcher
+					// if we successfully notify a watcher
+					// we need to remove the watcher from the list
+					// and decrease the counter
+					w.removed = true
+					l.Remove(curr)
+					atomic.AddInt64(&wh.count, -1)
+					reportWatcherRemoved()
+				}
+			}
+
+			curr = next // update current to the next element in the list
+		}
+
+		if l.Len() == 0 {
+			// if we have notified all watcher in the list
+			// we can delete the list
+			delete(wh.watchers, nodePath)
+		}
+	}
+}
+
+// clone function clones the watcherHub and return the cloned one.
+// only clone the static content. do not clone the current watchers.
+func (wh *watcherHub) clone() *watcherHub {
+	clonedHistory := wh.EventHistory.clone()
+
+	return &watcherHub{
+		EventHistory: clonedHistory,
+	}
+}
+
+// isHidden checks to see if key path is considered hidden to watch path i.e. the
+// last element is hidden or it's within a hidden directory
+func isHidden(watchPath, keyPath string) bool {
+	// When deleting a directory, watchPath might be deeper than the actual keyPath
+	// For example, when deleting /foo we also need to notify watchers on /foo/bar.
+	if len(watchPath) > len(keyPath) {
+		return false
+	}
+	// if watch path is just a "/", after path will start without "/"
+	// add a "/" to deal with the special case when watchPath is "/"
+	afterPath := path.Clean("/" + keyPath[len(watchPath):])
+	return strings.Contains(afterPath, "/_")
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/cluster.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/cluster.go
new file mode 100644
index 0000000..a22e4af
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/cluster.go
@@ -0,0 +1,31 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2v3
+
+import (
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+func (s *v2v3Server) ID() types.ID {
+	// TODO: use an actual member ID
+	return types.ID(0xe7cd2f00d)
+}
+func (s *v2v3Server) ClientURLs() []string                  { panic("STUB") }
+func (s *v2v3Server) Members() []*membership.Member         { panic("STUB") }
+func (s *v2v3Server) Member(id types.ID) *membership.Member { panic("STUB") }
+func (s *v2v3Server) Version() *semver.Version              { panic("STUB") }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/doc.go
new file mode 100644
index 0000000..2ff372f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v2v3 provides a ServerV2 implementation backed by clientv3.Client.
+package v2v3
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/server.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/server.go
new file mode 100644
index 0000000..5ff9b96
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/server.go
@@ -0,0 +1,129 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2v3
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/go-semver/semver"
+	"go.uber.org/zap"
+)
+
+type fakeStats struct{}
+
+func (s *fakeStats) SelfStats() []byte   { return nil }
+func (s *fakeStats) LeaderStats() []byte { return nil }
+func (s *fakeStats) StoreStats() []byte  { return nil }
+
+type v2v3Server struct {
+	lg    *zap.Logger
+	c     *clientv3.Client
+	store *v2v3Store
+	fakeStats
+}
+
+func NewServer(lg *zap.Logger, c *clientv3.Client, pfx string) etcdserver.ServerPeer {
+	return &v2v3Server{lg: lg, c: c, store: newStore(c, pfx)}
+}
+
+func (s *v2v3Server) ClientCertAuthEnabled() bool { return false }
+
+func (s *v2v3Server) LeaseHandler() http.Handler { panic("STUB: lease handler") }
+func (s *v2v3Server) RaftHandler() http.Handler  { panic("STUB: raft handler") }
+
+func (s *v2v3Server) Leader() types.ID {
+	ctx, cancel := context.WithTimeout(context.TODO(), 5*time.Second)
+	defer cancel()
+	resp, err := s.c.Status(ctx, s.c.Endpoints()[0])
+	if err != nil {
+		return 0
+	}
+	return types.ID(resp.Leader)
+}
+
+func (s *v2v3Server) AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) {
+	// adding member as learner is not supported by V2 Server.
+	resp, err := s.c.MemberAdd(ctx, memb.PeerURLs)
+	if err != nil {
+		return nil, err
+	}
+	return v3MembersToMembership(resp.Members), nil
+}
+
+func (s *v2v3Server) RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error) {
+	resp, err := s.c.MemberRemove(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	return v3MembersToMembership(resp.Members), nil
+}
+
+func (s *v2v3Server) PromoteMember(ctx context.Context, id uint64) ([]*membership.Member, error) {
+	resp, err := s.c.MemberPromote(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	return v3MembersToMembership(resp.Members), nil
+}
+
+func (s *v2v3Server) UpdateMember(ctx context.Context, m membership.Member) ([]*membership.Member, error) {
+	resp, err := s.c.MemberUpdate(ctx, uint64(m.ID), m.PeerURLs)
+	if err != nil {
+		return nil, err
+	}
+	return v3MembersToMembership(resp.Members), nil
+}
+
+func v3MembersToMembership(v3membs []*pb.Member) []*membership.Member {
+	membs := make([]*membership.Member, len(v3membs))
+	for i, m := range v3membs {
+		membs[i] = &membership.Member{
+			ID: types.ID(m.ID),
+			RaftAttributes: membership.RaftAttributes{
+				PeerURLs:  m.PeerURLs,
+				IsLearner: m.IsLearner,
+			},
+			Attributes: membership.Attributes{
+				Name:       m.Name,
+				ClientURLs: m.ClientURLs,
+			},
+		}
+	}
+	return membs
+}
+
+func (s *v2v3Server) ClusterVersion() *semver.Version { return s.Version() }
+func (s *v2v3Server) Cluster() api.Cluster            { return s }
+func (s *v2v3Server) Alarms() []*pb.AlarmMember       { return nil }
+
+func (s *v2v3Server) Do(ctx context.Context, r pb.Request) (etcdserver.Response, error) {
+	applier := etcdserver.NewApplierV2(s.lg, s.store, nil)
+	reqHandler := etcdserver.NewStoreRequestV2Handler(s.store, applier)
+	req := (*etcdserver.RequestV2)(&r)
+	resp, err := req.Handle(ctx, reqHandler)
+	if resp.Err != nil {
+		return resp, resp.Err
+	}
+	return resp, err
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/store.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/store.go
new file mode 100644
index 0000000..f1c7ab3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/store.go
@@ -0,0 +1,638 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2v3
+
+import (
+	"context"
+	"fmt"
+	"path"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/clientv3/concurrency"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+)
+
+// store implements the Store interface for V2 using
+// a v3 client.
+type v2v3Store struct {
+	c *clientv3.Client
+	// pfx is the v3 prefix where keys should be stored.
+	pfx string
+	ctx context.Context
+}
+
+const maxPathDepth = 63
+
+var errUnsupported = fmt.Errorf("TTLs are unsupported")
+
+func NewStore(c *clientv3.Client, pfx string) v2store.Store { return newStore(c, pfx) }
+
+func newStore(c *clientv3.Client, pfx string) *v2v3Store { return &v2v3Store{c, pfx, c.Ctx()} }
+
+func (s *v2v3Store) Index() uint64 { panic("STUB") }
+
+func (s *v2v3Store) Get(nodePath string, recursive, sorted bool) (*v2store.Event, error) {
+	key := s.mkPath(nodePath)
+	resp, err := s.c.Txn(s.ctx).Then(
+		clientv3.OpGet(key+"/"),
+		clientv3.OpGet(key),
+	).Commit()
+	if err != nil {
+		return nil, err
+	}
+
+	if kvs := resp.Responses[0].GetResponseRange().Kvs; len(kvs) != 0 || isRoot(nodePath) {
+		nodes, err := s.getDir(nodePath, recursive, sorted, resp.Header.Revision)
+		if err != nil {
+			return nil, err
+		}
+		cidx, midx := uint64(0), uint64(0)
+		if len(kvs) > 0 {
+			cidx, midx = mkV2Rev(kvs[0].CreateRevision), mkV2Rev(kvs[0].ModRevision)
+		}
+		return &v2store.Event{
+			Action: v2store.Get,
+			Node: &v2store.NodeExtern{
+				Key:           nodePath,
+				Dir:           true,
+				Nodes:         nodes,
+				CreatedIndex:  cidx,
+				ModifiedIndex: midx,
+			},
+			EtcdIndex: mkV2Rev(resp.Header.Revision),
+		}, nil
+	}
+
+	kvs := resp.Responses[1].GetResponseRange().Kvs
+	if len(kvs) == 0 {
+		return nil, v2error.NewError(v2error.EcodeKeyNotFound, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+
+	return &v2store.Event{
+		Action:    v2store.Get,
+		Node:      s.mkV2Node(kvs[0]),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) getDir(nodePath string, recursive, sorted bool, rev int64) ([]*v2store.NodeExtern, error) {
+	rootNodes, err := s.getDirDepth(nodePath, 1, rev)
+	if err != nil || !recursive {
+		if sorted {
+			sort.Sort(v2store.NodeExterns(rootNodes))
+		}
+		return rootNodes, err
+	}
+	nextNodes := rootNodes
+	nodes := make(map[string]*v2store.NodeExtern)
+	// Breadth walk the subdirectories
+	for i := 2; len(nextNodes) > 0; i++ {
+		for _, n := range nextNodes {
+			nodes[n.Key] = n
+			if parent := nodes[path.Dir(n.Key)]; parent != nil {
+				parent.Nodes = append(parent.Nodes, n)
+			}
+		}
+		if nextNodes, err = s.getDirDepth(nodePath, i, rev); err != nil {
+			return nil, err
+		}
+	}
+
+	if sorted {
+		sort.Sort(v2store.NodeExterns(rootNodes))
+	}
+	return rootNodes, nil
+}
+
+func (s *v2v3Store) getDirDepth(nodePath string, depth int, rev int64) ([]*v2store.NodeExtern, error) {
+	pd := s.mkPathDepth(nodePath, depth)
+	resp, err := s.c.Get(s.ctx, pd, clientv3.WithPrefix(), clientv3.WithRev(rev))
+	if err != nil {
+		return nil, err
+	}
+
+	nodes := make([]*v2store.NodeExtern, len(resp.Kvs))
+	for i, kv := range resp.Kvs {
+		nodes[i] = s.mkV2Node(kv)
+	}
+	return nodes, nil
+}
+
+func (s *v2v3Store) Set(
+	nodePath string,
+	dir bool,
+	value string,
+	expireOpts v2store.TTLOptionSet,
+) (*v2store.Event, error) {
+	if expireOpts.Refresh || !expireOpts.ExpireTime.IsZero() {
+		return nil, errUnsupported
+	}
+
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+
+	ecode := 0
+	applyf := func(stm concurrency.STM) error {
+		// build path if any directories in path do not exist
+		dirs := []string{}
+		for p := path.Dir(nodePath); !isRoot(p); p = path.Dir(p) {
+			pp := s.mkPath(p)
+			if stm.Rev(pp) > 0 {
+				ecode = v2error.EcodeNotDir
+				return nil
+			}
+			if stm.Rev(pp+"/") == 0 {
+				dirs = append(dirs, pp+"/")
+			}
+		}
+		for _, d := range dirs {
+			stm.Put(d, "")
+		}
+
+		key := s.mkPath(nodePath)
+		if dir {
+			if stm.Rev(key) != 0 {
+				// exists as non-dir
+				ecode = v2error.EcodeNotDir
+				return nil
+			}
+			key = key + "/"
+		} else if stm.Rev(key+"/") != 0 {
+			ecode = v2error.EcodeNotFile
+			return nil
+		}
+		stm.Put(key, value, clientv3.WithPrevKV())
+		stm.Put(s.mkActionKey(), v2store.Set)
+		return nil
+	}
+
+	resp, err := s.newSTM(applyf)
+	if err != nil {
+		return nil, err
+	}
+	if ecode != 0 {
+		return nil, v2error.NewError(ecode, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+
+	createRev := resp.Header.Revision
+	var pn *v2store.NodeExtern
+	if pkv := prevKeyFromPuts(resp); pkv != nil {
+		pn = s.mkV2Node(pkv)
+		createRev = pkv.CreateRevision
+	}
+
+	vp := &value
+	if dir {
+		vp = nil
+	}
+	return &v2store.Event{
+		Action: v2store.Set,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			Value:         vp,
+			Dir:           dir,
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+			CreatedIndex:  mkV2Rev(createRev),
+		},
+		PrevNode:  pn,
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) Update(nodePath, newValue string, expireOpts v2store.TTLOptionSet) (*v2store.Event, error) {
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+
+	if expireOpts.Refresh || !expireOpts.ExpireTime.IsZero() {
+		return nil, errUnsupported
+	}
+
+	key := s.mkPath(nodePath)
+	ecode := 0
+	applyf := func(stm concurrency.STM) error {
+		if rev := stm.Rev(key + "/"); rev != 0 {
+			ecode = v2error.EcodeNotFile
+			return nil
+		}
+		if rev := stm.Rev(key); rev == 0 {
+			ecode = v2error.EcodeKeyNotFound
+			return nil
+		}
+		stm.Put(key, newValue, clientv3.WithPrevKV())
+		stm.Put(s.mkActionKey(), v2store.Update)
+		return nil
+	}
+
+	resp, err := s.newSTM(applyf)
+	if err != nil {
+		return nil, err
+	}
+	if ecode != 0 {
+		return nil, v2error.NewError(v2error.EcodeNotFile, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+
+	pkv := prevKeyFromPuts(resp)
+	return &v2store.Event{
+		Action: v2store.Update,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			Value:         &newValue,
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+			CreatedIndex:  mkV2Rev(pkv.CreateRevision),
+		},
+		PrevNode:  s.mkV2Node(pkv),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) Create(
+	nodePath string,
+	dir bool,
+	value string,
+	unique bool,
+	expireOpts v2store.TTLOptionSet,
+) (*v2store.Event, error) {
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+	if expireOpts.Refresh || !expireOpts.ExpireTime.IsZero() {
+		return nil, errUnsupported
+	}
+	ecode := 0
+	applyf := func(stm concurrency.STM) error {
+		ecode = 0
+		key := s.mkPath(nodePath)
+		if unique {
+			// append unique item under the node path
+			for {
+				key = nodePath + "/" + fmt.Sprintf("%020s", time.Now())
+				key = path.Clean(path.Join("/", key))
+				key = s.mkPath(key)
+				if stm.Rev(key) == 0 {
+					break
+				}
+			}
+		}
+		if stm.Rev(key) > 0 || stm.Rev(key+"/") > 0 {
+			ecode = v2error.EcodeNodeExist
+			return nil
+		}
+		// build path if any directories in path do not exist
+		dirs := []string{}
+		for p := path.Dir(nodePath); !isRoot(p); p = path.Dir(p) {
+			pp := s.mkPath(p)
+			if stm.Rev(pp) > 0 {
+				ecode = v2error.EcodeNotDir
+				return nil
+			}
+			if stm.Rev(pp+"/") == 0 {
+				dirs = append(dirs, pp+"/")
+			}
+		}
+		for _, d := range dirs {
+			stm.Put(d, "")
+		}
+
+		if dir {
+			// directories marked with extra slash in key name
+			key += "/"
+		}
+		stm.Put(key, value)
+		stm.Put(s.mkActionKey(), v2store.Create)
+		return nil
+	}
+
+	resp, err := s.newSTM(applyf)
+	if err != nil {
+		return nil, err
+	}
+	if ecode != 0 {
+		return nil, v2error.NewError(ecode, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+
+	var v *string
+	if !dir {
+		v = &value
+	}
+
+	return &v2store.Event{
+		Action: v2store.Create,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			Value:         v,
+			Dir:           dir,
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+			CreatedIndex:  mkV2Rev(resp.Header.Revision),
+		},
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) CompareAndSwap(
+	nodePath string,
+	prevValue string,
+	prevIndex uint64,
+	value string,
+	expireOpts v2store.TTLOptionSet,
+) (*v2store.Event, error) {
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+	if expireOpts.Refresh || !expireOpts.ExpireTime.IsZero() {
+		return nil, errUnsupported
+	}
+
+	key := s.mkPath(nodePath)
+	resp, err := s.c.Txn(s.ctx).If(
+		s.mkCompare(nodePath, prevValue, prevIndex)...,
+	).Then(
+		clientv3.OpPut(key, value, clientv3.WithPrevKV()),
+		clientv3.OpPut(s.mkActionKey(), v2store.CompareAndSwap),
+	).Else(
+		clientv3.OpGet(key),
+		clientv3.OpGet(key+"/"),
+	).Commit()
+
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Succeeded {
+		return nil, compareFail(nodePath, prevValue, prevIndex, resp)
+	}
+
+	pkv := resp.Responses[0].GetResponsePut().PrevKv
+	return &v2store.Event{
+		Action: v2store.CompareAndSwap,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			Value:         &value,
+			CreatedIndex:  mkV2Rev(pkv.CreateRevision),
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+		},
+		PrevNode:  s.mkV2Node(pkv),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) Delete(nodePath string, dir, recursive bool) (*v2store.Event, error) {
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+	if !dir && !recursive {
+		return s.deleteNode(nodePath)
+	}
+	if !recursive {
+		return s.deleteEmptyDir(nodePath)
+	}
+
+	dels := make([]clientv3.Op, maxPathDepth+1)
+	dels[0] = clientv3.OpDelete(s.mkPath(nodePath)+"/", clientv3.WithPrevKV())
+	for i := 1; i < maxPathDepth; i++ {
+		dels[i] = clientv3.OpDelete(s.mkPathDepth(nodePath, i), clientv3.WithPrefix())
+	}
+	dels[maxPathDepth] = clientv3.OpPut(s.mkActionKey(), v2store.Delete)
+
+	resp, err := s.c.Txn(s.ctx).If(
+		clientv3.Compare(clientv3.Version(s.mkPath(nodePath)+"/"), ">", 0),
+		clientv3.Compare(clientv3.Version(s.mkPathDepth(nodePath, maxPathDepth)+"/"), "=", 0),
+	).Then(
+		dels...,
+	).Commit()
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Succeeded {
+		return nil, v2error.NewError(v2error.EcodeNodeExist, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	dresp := resp.Responses[0].GetResponseDeleteRange()
+	return &v2store.Event{
+		Action:    v2store.Delete,
+		PrevNode:  s.mkV2Node(dresp.PrevKvs[0]),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) deleteEmptyDir(nodePath string) (*v2store.Event, error) {
+	resp, err := s.c.Txn(s.ctx).If(
+		clientv3.Compare(clientv3.Version(s.mkPathDepth(nodePath, 1)), "=", 0).WithPrefix(),
+	).Then(
+		clientv3.OpDelete(s.mkPath(nodePath)+"/", clientv3.WithPrevKV()),
+		clientv3.OpPut(s.mkActionKey(), v2store.Delete),
+	).Commit()
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Succeeded {
+		return nil, v2error.NewError(v2error.EcodeDirNotEmpty, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	dresp := resp.Responses[0].GetResponseDeleteRange()
+	if len(dresp.PrevKvs) == 0 {
+		return nil, v2error.NewError(v2error.EcodeNodeExist, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	return &v2store.Event{
+		Action:    v2store.Delete,
+		PrevNode:  s.mkV2Node(dresp.PrevKvs[0]),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) deleteNode(nodePath string) (*v2store.Event, error) {
+	resp, err := s.c.Txn(s.ctx).If(
+		clientv3.Compare(clientv3.Version(s.mkPath(nodePath)+"/"), "=", 0),
+	).Then(
+		clientv3.OpDelete(s.mkPath(nodePath), clientv3.WithPrevKV()),
+		clientv3.OpPut(s.mkActionKey(), v2store.Delete),
+	).Commit()
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Succeeded {
+		return nil, v2error.NewError(v2error.EcodeNotFile, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	pkvs := resp.Responses[0].GetResponseDeleteRange().PrevKvs
+	if len(pkvs) == 0 {
+		return nil, v2error.NewError(v2error.EcodeKeyNotFound, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	pkv := pkvs[0]
+	return &v2store.Event{
+		Action: v2store.Delete,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			CreatedIndex:  mkV2Rev(pkv.CreateRevision),
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+		},
+		PrevNode:  s.mkV2Node(pkv),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func (s *v2v3Store) CompareAndDelete(nodePath, prevValue string, prevIndex uint64) (*v2store.Event, error) {
+	if isRoot(nodePath) {
+		return nil, v2error.NewError(v2error.EcodeRootROnly, nodePath, 0)
+	}
+
+	key := s.mkPath(nodePath)
+	resp, err := s.c.Txn(s.ctx).If(
+		s.mkCompare(nodePath, prevValue, prevIndex)...,
+	).Then(
+		clientv3.OpDelete(key, clientv3.WithPrevKV()),
+		clientv3.OpPut(s.mkActionKey(), v2store.CompareAndDelete),
+	).Else(
+		clientv3.OpGet(key),
+		clientv3.OpGet(key+"/"),
+	).Commit()
+
+	if err != nil {
+		return nil, err
+	}
+	if !resp.Succeeded {
+		return nil, compareFail(nodePath, prevValue, prevIndex, resp)
+	}
+
+	// len(pkvs) > 1 since txn only succeeds when key exists
+	pkv := resp.Responses[0].GetResponseDeleteRange().PrevKvs[0]
+	return &v2store.Event{
+		Action: v2store.CompareAndDelete,
+		Node: &v2store.NodeExtern{
+			Key:           nodePath,
+			CreatedIndex:  mkV2Rev(pkv.CreateRevision),
+			ModifiedIndex: mkV2Rev(resp.Header.Revision),
+		},
+		PrevNode:  s.mkV2Node(pkv),
+		EtcdIndex: mkV2Rev(resp.Header.Revision),
+	}, nil
+}
+
+func compareFail(nodePath, prevValue string, prevIndex uint64, resp *clientv3.TxnResponse) error {
+	if dkvs := resp.Responses[1].GetResponseRange().Kvs; len(dkvs) > 0 {
+		return v2error.NewError(v2error.EcodeNotFile, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	kvs := resp.Responses[0].GetResponseRange().Kvs
+	if len(kvs) == 0 {
+		return v2error.NewError(v2error.EcodeKeyNotFound, nodePath, mkV2Rev(resp.Header.Revision))
+	}
+	kv := kvs[0]
+	indexMatch := prevIndex == 0 || kv.ModRevision == int64(prevIndex)
+	valueMatch := prevValue == "" || string(kv.Value) == prevValue
+	var cause string
+	switch {
+	case indexMatch && !valueMatch:
+		cause = fmt.Sprintf("[%v != %v]", prevValue, string(kv.Value))
+	case valueMatch && !indexMatch:
+		cause = fmt.Sprintf("[%v != %v]", prevIndex, kv.ModRevision)
+	default:
+		cause = fmt.Sprintf("[%v != %v] [%v != %v]", prevValue, string(kv.Value), prevIndex, kv.ModRevision)
+	}
+	return v2error.NewError(v2error.EcodeTestFailed, cause, mkV2Rev(resp.Header.Revision))
+}
+
+func (s *v2v3Store) mkCompare(nodePath, prevValue string, prevIndex uint64) []clientv3.Cmp {
+	key := s.mkPath(nodePath)
+	cmps := []clientv3.Cmp{clientv3.Compare(clientv3.Version(key), ">", 0)}
+	if prevIndex != 0 {
+		cmps = append(cmps, clientv3.Compare(clientv3.ModRevision(key), "=", mkV3Rev(prevIndex)))
+	}
+	if prevValue != "" {
+		cmps = append(cmps, clientv3.Compare(clientv3.Value(key), "=", prevValue))
+	}
+	return cmps
+}
+
+func (s *v2v3Store) JsonStats() []byte                  { panic("STUB") }
+func (s *v2v3Store) DeleteExpiredKeys(cutoff time.Time) { panic("STUB") }
+
+func (s *v2v3Store) Version() int { return 2 }
+
+// TODO: move this out of the Store interface?
+
+func (s *v2v3Store) Save() ([]byte, error)       { panic("STUB") }
+func (s *v2v3Store) Recovery(state []byte) error { panic("STUB") }
+func (s *v2v3Store) Clone() v2store.Store        { panic("STUB") }
+func (s *v2v3Store) SaveNoCopy() ([]byte, error) { panic("STUB") }
+func (s *v2v3Store) HasTTLKeys() bool            { panic("STUB") }
+
+func (s *v2v3Store) mkPath(nodePath string) string { return s.mkPathDepth(nodePath, 0) }
+
+func (s *v2v3Store) mkNodePath(p string) string {
+	return path.Clean(p[len(s.pfx)+len("/k/000/"):])
+}
+
+// mkPathDepth makes a path to a key that encodes its directory depth
+// for fast directory listing. If a depth is provided, it is added
+// to the computed depth.
+func (s *v2v3Store) mkPathDepth(nodePath string, depth int) string {
+	normalForm := path.Clean(path.Join("/", nodePath))
+	n := strings.Count(normalForm, "/") + depth
+	return fmt.Sprintf("%s/%03d/k/%s", s.pfx, n, normalForm)
+}
+
+func (s *v2v3Store) mkActionKey() string { return s.pfx + "/act" }
+
+func isRoot(s string) bool { return len(s) == 0 || s == "/" || s == "/0" || s == "/1" }
+
+func mkV2Rev(v3Rev int64) uint64 {
+	if v3Rev == 0 {
+		return 0
+	}
+	return uint64(v3Rev - 1)
+}
+
+func mkV3Rev(v2Rev uint64) int64 {
+	if v2Rev == 0 {
+		return 0
+	}
+	return int64(v2Rev + 1)
+}
+
+// mkV2Node creates a V2 NodeExtern from a V3 KeyValue
+func (s *v2v3Store) mkV2Node(kv *mvccpb.KeyValue) *v2store.NodeExtern {
+	if kv == nil {
+		return nil
+	}
+	n := &v2store.NodeExtern{
+		Key:           s.mkNodePath(string(kv.Key)),
+		Dir:           kv.Key[len(kv.Key)-1] == '/',
+		CreatedIndex:  mkV2Rev(kv.CreateRevision),
+		ModifiedIndex: mkV2Rev(kv.ModRevision),
+	}
+	if !n.Dir {
+		v := string(kv.Value)
+		n.Value = &v
+	}
+	return n
+}
+
+// prevKeyFromPuts gets the prev key that is being put; ignores
+// the put action response.
+func prevKeyFromPuts(resp *clientv3.TxnResponse) *mvccpb.KeyValue {
+	for _, r := range resp.Responses {
+		pkv := r.GetResponsePut().PrevKv
+		if pkv != nil && pkv.CreateRevision > 0 {
+			return pkv
+		}
+	}
+	return nil
+}
+
+func (s *v2v3Store) newSTM(applyf func(concurrency.STM) error) (*clientv3.TxnResponse, error) {
+	return concurrency.NewSTM(s.c, applyf, concurrency.WithIsolation(concurrency.Serializable))
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/watcher.go b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/watcher.go
new file mode 100644
index 0000000..e8a3557
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v2v3/watcher.go
@@ -0,0 +1,140 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2v3
+
+import (
+	"context"
+	"strings"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/etcdserver/api/v2error"
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+)
+
+func (s *v2v3Store) Watch(prefix string, recursive, stream bool, sinceIndex uint64) (v2store.Watcher, error) {
+	ctx, cancel := context.WithCancel(s.ctx)
+	wch := s.c.Watch(
+		ctx,
+		// TODO: very pricey; use a single store-wide watch in future
+		s.pfx,
+		clientv3.WithPrefix(),
+		clientv3.WithRev(int64(sinceIndex)),
+		clientv3.WithCreatedNotify(),
+		clientv3.WithPrevKV())
+	resp, ok := <-wch
+	if err := resp.Err(); err != nil || !ok {
+		cancel()
+		return nil, v2error.NewError(v2error.EcodeRaftInternal, prefix, 0)
+	}
+
+	evc, donec := make(chan *v2store.Event), make(chan struct{})
+	go func() {
+		defer func() {
+			close(evc)
+			close(donec)
+		}()
+		for resp := range wch {
+			for _, ev := range s.mkV2Events(resp) {
+				k := ev.Node.Key
+				if recursive {
+					if !strings.HasPrefix(k, prefix) {
+						continue
+					}
+					// accept events on hidden keys given in prefix
+					k = strings.Replace(k, prefix, "/", 1)
+					// ignore hidden keys deeper than prefix
+					if strings.Contains(k, "/_") {
+						continue
+					}
+				}
+				if !recursive && k != prefix {
+					continue
+				}
+				select {
+				case evc <- ev:
+				case <-ctx.Done():
+					return
+				}
+				if !stream {
+					return
+				}
+			}
+		}
+	}()
+
+	return &v2v3Watcher{
+		startRev: resp.Header.Revision,
+		evc:      evc,
+		donec:    donec,
+		cancel:   cancel,
+	}, nil
+}
+
+func (s *v2v3Store) mkV2Events(wr clientv3.WatchResponse) (evs []*v2store.Event) {
+	ak := s.mkActionKey()
+	for _, rev := range mkRevs(wr) {
+		var act, key *clientv3.Event
+		for _, ev := range rev {
+			if string(ev.Kv.Key) == ak {
+				act = ev
+			} else if key != nil && len(key.Kv.Key) < len(ev.Kv.Key) {
+				// use longest key to ignore intermediate new
+				// directories from Create.
+				key = ev
+			} else if key == nil {
+				key = ev
+			}
+		}
+		v2ev := &v2store.Event{
+			Action:    string(act.Kv.Value),
+			Node:      s.mkV2Node(key.Kv),
+			PrevNode:  s.mkV2Node(key.PrevKv),
+			EtcdIndex: mkV2Rev(wr.Header.Revision),
+		}
+		evs = append(evs, v2ev)
+	}
+	return evs
+}
+
+func mkRevs(wr clientv3.WatchResponse) (revs [][]*clientv3.Event) {
+	var curRev []*clientv3.Event
+	for _, ev := range wr.Events {
+		if curRev != nil && ev.Kv.ModRevision != curRev[0].Kv.ModRevision {
+			revs = append(revs, curRev)
+			curRev = nil
+		}
+		curRev = append(curRev, ev)
+	}
+	if curRev != nil {
+		revs = append(revs, curRev)
+	}
+	return revs
+}
+
+type v2v3Watcher struct {
+	startRev int64
+	evc      chan *v2store.Event
+	donec    chan struct{}
+	cancel   context.CancelFunc
+}
+
+func (w *v2v3Watcher) StartIndex() uint64 { return mkV2Rev(w.startRev) }
+
+func (w *v2v3Watcher) Remove() {
+	w.cancel()
+	<-w.donec
+}
+
+func (w *v2v3Watcher) EventChan() chan *v2store.Event { return w.evc }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3alarm/alarms.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3alarm/alarms.go
new file mode 100644
index 0000000..2b085a8
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3alarm/alarms.go
@@ -0,0 +1,153 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3alarm manages health status alarms in etcd.
+package v3alarm
+
+import (
+	"sync"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+var (
+	alarmBucketName = []byte("alarm")
+	plog            = capnslog.NewPackageLogger("go.etcd.io/etcd", "alarm")
+)
+
+type BackendGetter interface {
+	Backend() backend.Backend
+}
+
+type alarmSet map[types.ID]*pb.AlarmMember
+
+// AlarmStore persists alarms to the backend.
+type AlarmStore struct {
+	mu    sync.Mutex
+	types map[pb.AlarmType]alarmSet
+
+	bg BackendGetter
+}
+
+func NewAlarmStore(bg BackendGetter) (*AlarmStore, error) {
+	ret := &AlarmStore{types: make(map[pb.AlarmType]alarmSet), bg: bg}
+	err := ret.restore()
+	return ret, err
+}
+
+func (a *AlarmStore) Activate(id types.ID, at pb.AlarmType) *pb.AlarmMember {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	newAlarm := &pb.AlarmMember{MemberID: uint64(id), Alarm: at}
+	if m := a.addToMap(newAlarm); m != newAlarm {
+		return m
+	}
+
+	v, err := newAlarm.Marshal()
+	if err != nil {
+		plog.Panicf("failed to marshal alarm member")
+	}
+
+	b := a.bg.Backend()
+	b.BatchTx().Lock()
+	b.BatchTx().UnsafePut(alarmBucketName, v, nil)
+	b.BatchTx().Unlock()
+
+	return newAlarm
+}
+
+func (a *AlarmStore) Deactivate(id types.ID, at pb.AlarmType) *pb.AlarmMember {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	t := a.types[at]
+	if t == nil {
+		t = make(alarmSet)
+		a.types[at] = t
+	}
+	m := t[id]
+	if m == nil {
+		return nil
+	}
+
+	delete(t, id)
+
+	v, err := m.Marshal()
+	if err != nil {
+		plog.Panicf("failed to marshal alarm member")
+	}
+
+	b := a.bg.Backend()
+	b.BatchTx().Lock()
+	b.BatchTx().UnsafeDelete(alarmBucketName, v)
+	b.BatchTx().Unlock()
+
+	return m
+}
+
+func (a *AlarmStore) Get(at pb.AlarmType) (ret []*pb.AlarmMember) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if at == pb.AlarmType_NONE {
+		for _, t := range a.types {
+			for _, m := range t {
+				ret = append(ret, m)
+			}
+		}
+		return ret
+	}
+	for _, m := range a.types[at] {
+		ret = append(ret, m)
+	}
+	return ret
+}
+
+func (a *AlarmStore) restore() error {
+	b := a.bg.Backend()
+	tx := b.BatchTx()
+
+	tx.Lock()
+	tx.UnsafeCreateBucket(alarmBucketName)
+	err := tx.UnsafeForEach(alarmBucketName, func(k, v []byte) error {
+		var m pb.AlarmMember
+		if err := m.Unmarshal(k); err != nil {
+			return err
+		}
+		a.addToMap(&m)
+		return nil
+	})
+	tx.Unlock()
+
+	b.ForceCommit()
+	return err
+}
+
+func (a *AlarmStore) addToMap(newAlarm *pb.AlarmMember) *pb.AlarmMember {
+	t := a.types[newAlarm.Alarm]
+	if t == nil {
+		t = make(alarmSet)
+		a.types[newAlarm.Alarm] = t
+	}
+	m := t[types.ID(newAlarm.MemberID)]
+	if m != nil {
+		return m
+	}
+	t[types.ID(newAlarm.MemberID)] = newAlarm
+	return newAlarm
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go
new file mode 100644
index 0000000..47922c4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/doc.go
@@ -0,0 +1,45 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3client provides clientv3 interfaces from an etcdserver.
+//
+// Use v3client by creating an EtcdServer instance, then wrapping it with v3client.New:
+//
+//	import (
+//		"context"
+//
+//		"go.etcd.io/etcd/embed"
+//		"go.etcd.io/etcd/etcdserver/api/v3client"
+//	)
+//
+//	...
+//
+//	// create an embedded EtcdServer from the default configuration
+//	cfg := embed.NewConfig()
+//	cfg.Dir = "default.etcd"
+//	e, err := embed.StartEtcd(cfg)
+//	if err != nil {
+//		// handle error!
+//	}
+//
+//	// wrap the EtcdServer with v3client
+//	cli := v3client.New(e.Server)
+//
+//	// use like an ordinary clientv3
+//	resp, err := cli.Put(context.TODO(), "some-key", "it works!")
+//	if err != nil {
+//		// handle error!
+//	}
+//
+package v3client
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3client/v3client.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/v3client.go
new file mode 100644
index 0000000..d203121
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3client/v3client.go
@@ -0,0 +1,66 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3client
+
+import (
+	"context"
+	"time"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc"
+	"go.etcd.io/etcd/proxy/grpcproxy/adapter"
+)
+
+// New creates a clientv3 client that wraps an in-process EtcdServer. Instead
+// of making gRPC calls through sockets, the client makes direct function calls
+// to the etcd server through its api/v3rpc function interfaces.
+func New(s *etcdserver.EtcdServer) *clientv3.Client {
+	c := clientv3.NewCtxClient(context.Background())
+
+	kvc := adapter.KvServerToKvClient(v3rpc.NewQuotaKVServer(s))
+	c.KV = clientv3.NewKVFromKVClient(kvc, c)
+
+	lc := adapter.LeaseServerToLeaseClient(v3rpc.NewQuotaLeaseServer(s))
+	c.Lease = clientv3.NewLeaseFromLeaseClient(lc, c, time.Second)
+
+	wc := adapter.WatchServerToWatchClient(v3rpc.NewWatchServer(s))
+	c.Watcher = &watchWrapper{clientv3.NewWatchFromWatchClient(wc, c)}
+
+	mc := adapter.MaintenanceServerToMaintenanceClient(v3rpc.NewMaintenanceServer(s))
+	c.Maintenance = clientv3.NewMaintenanceFromMaintenanceClient(mc, c)
+
+	clc := adapter.ClusterServerToClusterClient(v3rpc.NewClusterServer(s))
+	c.Cluster = clientv3.NewClusterFromClusterClient(clc, c)
+
+	// TODO: implement clientv3.Auth interface?
+
+	return c
+}
+
+// BlankContext implements Stringer on a context so the ctx string doesn't
+// depend on the context's WithValue data, which tends to be unsynchronized
+// (e.g., x/net/trace), causing ctx.String() to throw data races.
+type blankContext struct{ context.Context }
+
+func (*blankContext) String() string { return "(blankCtx)" }
+
+// watchWrapper wraps clientv3 watch calls to blank out the context
+// to avoid races on trace data.
+type watchWrapper struct{ clientv3.Watcher }
+
+func (ww *watchWrapper) Watch(ctx context.Context, key string, opts ...clientv3.OpOption) clientv3.WatchChan {
+	return ww.Watcher.Watch(&blankContext{ctx}, key, opts...)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/compactor.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/compactor.go
new file mode 100644
index 0000000..73a9684
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/compactor.go
@@ -0,0 +1,75 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3compactor
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"github.com/coreos/pkg/capnslog"
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "compactor")
+)
+
+const (
+	ModePeriodic = "periodic"
+	ModeRevision = "revision"
+)
+
+// Compactor purges old log from the storage periodically.
+type Compactor interface {
+	// Run starts the main loop of the compactor in background.
+	// Use Stop() to halt the loop and release the resource.
+	Run()
+	// Stop halts the main loop of the compactor.
+	Stop()
+	// Pause temporally suspend the compactor not to run compaction. Resume() to unpose.
+	Pause()
+	// Resume restarts the compactor suspended by Pause().
+	Resume()
+}
+
+type Compactable interface {
+	Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error)
+}
+
+type RevGetter interface {
+	Rev() int64
+}
+
+// New returns a new Compactor based on given "mode".
+func New(
+	lg *zap.Logger,
+	mode string,
+	retention time.Duration,
+	rg RevGetter,
+	c Compactable,
+) (Compactor, error) {
+	switch mode {
+	case ModePeriodic:
+		return newPeriodic(lg, clockwork.NewRealClock(), retention, rg, c), nil
+	case ModeRevision:
+		return newRevision(lg, clockwork.NewRealClock(), int64(retention), rg, c), nil
+	default:
+		return nil, fmt.Errorf("unsupported compaction mode %s", mode)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/doc.go
new file mode 100644
index 0000000..bb28046
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3compactor implements automated policies for compacting etcd's mvcc storage.
+package v3compactor
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/periodic.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/periodic.go
new file mode 100644
index 0000000..ab64cb7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/periodic.go
@@ -0,0 +1,217 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3compactor
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+// Periodic compacts the log by purging revisions older than
+// the configured retention time.
+type Periodic struct {
+	lg     *zap.Logger
+	clock  clockwork.Clock
+	period time.Duration
+
+	rg RevGetter
+	c  Compactable
+
+	revs   []int64
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	// mu protects paused
+	mu     sync.RWMutex
+	paused bool
+}
+
+// newPeriodic creates a new instance of Periodic compactor that purges
+// the log older than h Duration.
+func newPeriodic(lg *zap.Logger, clock clockwork.Clock, h time.Duration, rg RevGetter, c Compactable) *Periodic {
+	pc := &Periodic{
+		lg:     lg,
+		clock:  clock,
+		period: h,
+		rg:     rg,
+		c:      c,
+		revs:   make([]int64, 0),
+	}
+	pc.ctx, pc.cancel = context.WithCancel(context.Background())
+	return pc
+}
+
+/*
+Compaction period 1-hour:
+  1. compute compaction period, which is 1-hour
+  2. record revisions for every 1/10 of 1-hour (6-minute)
+  3. keep recording revisions with no compaction for first 1-hour
+  4. do compact with revs[0]
+	- success? contiue on for-loop and move sliding window; revs = revs[1:]
+	- failure? update revs, and retry after 1/10 of 1-hour (6-minute)
+
+Compaction period 24-hour:
+  1. compute compaction period, which is 1-hour
+  2. record revisions for every 1/10 of 1-hour (6-minute)
+  3. keep recording revisions with no compaction for first 24-hour
+  4. do compact with revs[0]
+	- success? contiue on for-loop and move sliding window; revs = revs[1:]
+	- failure? update revs, and retry after 1/10 of 1-hour (6-minute)
+
+Compaction period 59-min:
+  1. compute compaction period, which is 59-min
+  2. record revisions for every 1/10 of 59-min (5.9-min)
+  3. keep recording revisions with no compaction for first 59-min
+  4. do compact with revs[0]
+	- success? contiue on for-loop and move sliding window; revs = revs[1:]
+	- failure? update revs, and retry after 1/10 of 59-min (5.9-min)
+
+Compaction period 5-sec:
+  1. compute compaction period, which is 5-sec
+  2. record revisions for every 1/10 of 5-sec (0.5-sec)
+  3. keep recording revisions with no compaction for first 5-sec
+  4. do compact with revs[0]
+	- success? contiue on for-loop and move sliding window; revs = revs[1:]
+	- failure? update revs, and retry after 1/10 of 5-sec (0.5-sec)
+*/
+
+// Run runs periodic compactor.
+func (pc *Periodic) Run() {
+	compactInterval := pc.getCompactInterval()
+	retryInterval := pc.getRetryInterval()
+	retentions := pc.getRetentions()
+
+	go func() {
+		lastSuccess := pc.clock.Now()
+		baseInterval := pc.period
+		for {
+			pc.revs = append(pc.revs, pc.rg.Rev())
+			if len(pc.revs) > retentions {
+				pc.revs = pc.revs[1:] // pc.revs[0] is always the rev at pc.period ago
+			}
+
+			select {
+			case <-pc.ctx.Done():
+				return
+			case <-pc.clock.After(retryInterval):
+				pc.mu.Lock()
+				p := pc.paused
+				pc.mu.Unlock()
+				if p {
+					continue
+				}
+			}
+
+			if pc.clock.Now().Sub(lastSuccess) < baseInterval {
+				continue
+			}
+
+			// wait up to initial given period
+			if baseInterval == pc.period {
+				baseInterval = compactInterval
+			}
+			rev := pc.revs[0]
+
+			if pc.lg != nil {
+				pc.lg.Info(
+					"starting auto periodic compaction",
+					zap.Int64("revision", rev),
+					zap.Duration("compact-period", pc.period),
+				)
+			} else {
+				plog.Noticef("Starting auto-compaction at revision %d (retention: %v)", rev, pc.period)
+			}
+			_, err := pc.c.Compact(pc.ctx, &pb.CompactionRequest{Revision: rev})
+			if err == nil || err == mvcc.ErrCompacted {
+				if pc.lg != nil {
+					pc.lg.Info(
+						"completed auto periodic compaction",
+						zap.Int64("revision", rev),
+						zap.Duration("compact-period", pc.period),
+						zap.Duration("took", time.Since(lastSuccess)),
+					)
+				} else {
+					plog.Noticef("Finished auto-compaction at revision %d", rev)
+				}
+				lastSuccess = pc.clock.Now()
+			} else {
+				if pc.lg != nil {
+					pc.lg.Warn(
+						"failed auto periodic compaction",
+						zap.Int64("revision", rev),
+						zap.Duration("compact-period", pc.period),
+						zap.Duration("retry-interval", retryInterval),
+						zap.Error(err),
+					)
+				} else {
+					plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err)
+					plog.Noticef("Retry after %v", retryInterval)
+				}
+			}
+		}
+	}()
+}
+
+// if given compaction period x is <1-hour, compact every x duration.
+// (e.g. --auto-compaction-mode 'periodic' --auto-compaction-retention='10m', then compact every 10-minute)
+// if given compaction period x is >1-hour, compact every hour.
+// (e.g. --auto-compaction-mode 'periodic' --auto-compaction-retention='2h', then compact every 1-hour)
+func (pc *Periodic) getCompactInterval() time.Duration {
+	itv := pc.period
+	if itv > time.Hour {
+		itv = time.Hour
+	}
+	return itv
+}
+
+func (pc *Periodic) getRetentions() int {
+	return int(pc.period/pc.getRetryInterval()) + 1
+}
+
+const retryDivisor = 10
+
+func (pc *Periodic) getRetryInterval() time.Duration {
+	itv := pc.period
+	if itv > time.Hour {
+		itv = time.Hour
+	}
+	return itv / retryDivisor
+}
+
+// Stop stops periodic compactor.
+func (pc *Periodic) Stop() {
+	pc.cancel()
+}
+
+// Pause pauses periodic compactor.
+func (pc *Periodic) Pause() {
+	pc.mu.Lock()
+	pc.paused = true
+	pc.mu.Unlock()
+}
+
+// Resume resumes periodic compactor.
+func (pc *Periodic) Resume() {
+	pc.mu.Lock()
+	pc.paused = false
+	pc.mu.Unlock()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go
new file mode 100644
index 0000000..cf8ac43
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go
@@ -0,0 +1,143 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3compactor
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+// Revision compacts the log by purging revisions older than
+// the configured reivison number. Compaction happens every 5 minutes.
+type Revision struct {
+	lg *zap.Logger
+
+	clock     clockwork.Clock
+	retention int64
+
+	rg RevGetter
+	c  Compactable
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	mu     sync.Mutex
+	paused bool
+}
+
+// newRevision creates a new instance of Revisonal compactor that purges
+// the log older than retention revisions from the current revision.
+func newRevision(lg *zap.Logger, clock clockwork.Clock, retention int64, rg RevGetter, c Compactable) *Revision {
+	rc := &Revision{
+		lg:        lg,
+		clock:     clock,
+		retention: retention,
+		rg:        rg,
+		c:         c,
+	}
+	rc.ctx, rc.cancel = context.WithCancel(context.Background())
+	return rc
+}
+
+const revInterval = 5 * time.Minute
+
+// Run runs revision-based compactor.
+func (rc *Revision) Run() {
+	prev := int64(0)
+	go func() {
+		for {
+			select {
+			case <-rc.ctx.Done():
+				return
+			case <-rc.clock.After(revInterval):
+				rc.mu.Lock()
+				p := rc.paused
+				rc.mu.Unlock()
+				if p {
+					continue
+				}
+			}
+
+			rev := rc.rg.Rev() - rc.retention
+			if rev <= 0 || rev == prev {
+				continue
+			}
+
+			now := time.Now()
+			if rc.lg != nil {
+				rc.lg.Info(
+					"starting auto revision compaction",
+					zap.Int64("revision", rev),
+					zap.Int64("revision-compaction-retention", rc.retention),
+				)
+			} else {
+				plog.Noticef("Starting auto-compaction at revision %d (retention: %d revisions)", rev, rc.retention)
+			}
+			_, err := rc.c.Compact(rc.ctx, &pb.CompactionRequest{Revision: rev})
+			if err == nil || err == mvcc.ErrCompacted {
+				prev = rev
+				if rc.lg != nil {
+					rc.lg.Info(
+						"completed auto revision compaction",
+						zap.Int64("revision", rev),
+						zap.Int64("revision-compaction-retention", rc.retention),
+						zap.Duration("took", time.Since(now)),
+					)
+				} else {
+					plog.Noticef("Finished auto-compaction at revision %d", rev)
+				}
+			} else {
+				if rc.lg != nil {
+					rc.lg.Warn(
+						"failed auto revision compaction",
+						zap.Int64("revision", rev),
+						zap.Int64("revision-compaction-retention", rc.retention),
+						zap.Duration("retry-interval", revInterval),
+						zap.Error(err),
+					)
+				} else {
+					plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err)
+					plog.Noticef("Retry after %v", revInterval)
+				}
+			}
+		}
+	}()
+}
+
+// Stop stops revision-based compactor.
+func (rc *Revision) Stop() {
+	rc.cancel()
+}
+
+// Pause pauses revision-based compactor.
+func (rc *Revision) Pause() {
+	rc.mu.Lock()
+	rc.paused = true
+	rc.mu.Unlock()
+}
+
+// Resume resumes revision-based compactor.
+func (rc *Revision) Resume() {
+	rc.mu.Lock()
+	rc.paused = false
+	rc.mu.Unlock()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3election/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/doc.go
new file mode 100644
index 0000000..d6fefd7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3election provides a v3 election service from an etcdserver.
+package v3election
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3election/election.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/election.go
new file mode 100644
index 0000000..f5a3be3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/election.go
@@ -0,0 +1,134 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3election
+
+import (
+	"context"
+	"errors"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/clientv3/concurrency"
+	epb "go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb"
+)
+
+// ErrMissingLeaderKey is returned when election API request
+// is missing the "leader" field.
+var ErrMissingLeaderKey = errors.New(`"leader" field must be provided`)
+
+type electionServer struct {
+	c *clientv3.Client
+}
+
+func NewElectionServer(c *clientv3.Client) epb.ElectionServer {
+	return &electionServer{c}
+}
+
+func (es *electionServer) Campaign(ctx context.Context, req *epb.CampaignRequest) (*epb.CampaignResponse, error) {
+	s, err := es.session(ctx, req.Lease)
+	if err != nil {
+		return nil, err
+	}
+	e := concurrency.NewElection(s, string(req.Name))
+	if err = e.Campaign(ctx, string(req.Value)); err != nil {
+		return nil, err
+	}
+	return &epb.CampaignResponse{
+		Header: e.Header(),
+		Leader: &epb.LeaderKey{
+			Name:  req.Name,
+			Key:   []byte(e.Key()),
+			Rev:   e.Rev(),
+			Lease: int64(s.Lease()),
+		},
+	}, nil
+}
+
+func (es *electionServer) Proclaim(ctx context.Context, req *epb.ProclaimRequest) (*epb.ProclaimResponse, error) {
+	if req.Leader == nil {
+		return nil, ErrMissingLeaderKey
+	}
+	s, err := es.session(ctx, req.Leader.Lease)
+	if err != nil {
+		return nil, err
+	}
+	e := concurrency.ResumeElection(s, string(req.Leader.Name), string(req.Leader.Key), req.Leader.Rev)
+	if err := e.Proclaim(ctx, string(req.Value)); err != nil {
+		return nil, err
+	}
+	return &epb.ProclaimResponse{Header: e.Header()}, nil
+}
+
+func (es *electionServer) Observe(req *epb.LeaderRequest, stream epb.Election_ObserveServer) error {
+	s, err := es.session(stream.Context(), -1)
+	if err != nil {
+		return err
+	}
+	e := concurrency.NewElection(s, string(req.Name))
+	ch := e.Observe(stream.Context())
+	for stream.Context().Err() == nil {
+		select {
+		case <-stream.Context().Done():
+		case resp, ok := <-ch:
+			if !ok {
+				return nil
+			}
+			lresp := &epb.LeaderResponse{Header: resp.Header, Kv: resp.Kvs[0]}
+			if err := stream.Send(lresp); err != nil {
+				return err
+			}
+		}
+	}
+	return stream.Context().Err()
+}
+
+func (es *electionServer) Leader(ctx context.Context, req *epb.LeaderRequest) (*epb.LeaderResponse, error) {
+	s, err := es.session(ctx, -1)
+	if err != nil {
+		return nil, err
+	}
+	l, lerr := concurrency.NewElection(s, string(req.Name)).Leader(ctx)
+	if lerr != nil {
+		return nil, lerr
+	}
+	return &epb.LeaderResponse{Header: l.Header, Kv: l.Kvs[0]}, nil
+}
+
+func (es *electionServer) Resign(ctx context.Context, req *epb.ResignRequest) (*epb.ResignResponse, error) {
+	if req.Leader == nil {
+		return nil, ErrMissingLeaderKey
+	}
+	s, err := es.session(ctx, req.Leader.Lease)
+	if err != nil {
+		return nil, err
+	}
+	e := concurrency.ResumeElection(s, string(req.Leader.Name), string(req.Leader.Key), req.Leader.Rev)
+	if err := e.Resign(ctx); err != nil {
+		return nil, err
+	}
+	return &epb.ResignResponse{Header: e.Header()}, nil
+}
+
+func (es *electionServer) session(ctx context.Context, lease int64) (*concurrency.Session, error) {
+	s, err := concurrency.NewSession(
+		es.c,
+		concurrency.WithLease(clientv3.LeaseID(lease)),
+		concurrency.WithContext(ctx),
+	)
+	if err != nil {
+		return nil, err
+	}
+	s.Orphan()
+	return s, nil
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/gw/v3election.pb.gw.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/gw/v3election.pb.gw.go
new file mode 100644
index 0000000..23551b5
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/gw/v3election.pb.gw.go
@@ -0,0 +1,313 @@
+// Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
+// source: etcdserver/api/v3election/v3electionpb/v3election.proto
+
+/*
+Package v3electionpb is a reverse proxy.
+
+It translates gRPC into RESTful JSON APIs.
+*/
+package gw
+
+import (
+	"go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+var _ codes.Code
+var _ io.Reader
+var _ status.Status
+var _ = runtime.String
+var _ = utilities.NewDoubleArray
+
+func request_Election_Campaign_0(ctx context.Context, marshaler runtime.Marshaler, client v3electionpb.ElectionClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3electionpb.CampaignRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Campaign(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Election_Proclaim_0(ctx context.Context, marshaler runtime.Marshaler, client v3electionpb.ElectionClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3electionpb.ProclaimRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Proclaim(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Election_Leader_0(ctx context.Context, marshaler runtime.Marshaler, client v3electionpb.ElectionClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3electionpb.LeaderRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Leader(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Election_Observe_0(ctx context.Context, marshaler runtime.Marshaler, client v3electionpb.ElectionClient, req *http.Request, pathParams map[string]string) (v3electionpb.Election_ObserveClient, runtime.ServerMetadata, error) {
+	var protoReq v3electionpb.LeaderRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	stream, err := client.Observe(ctx, &protoReq)
+	if err != nil {
+		return nil, metadata, err
+	}
+	header, err := stream.Header()
+	if err != nil {
+		return nil, metadata, err
+	}
+	metadata.HeaderMD = header
+	return stream, metadata, nil
+
+}
+
+func request_Election_Resign_0(ctx context.Context, marshaler runtime.Marshaler, client v3electionpb.ElectionClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3electionpb.ResignRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Resign(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+// RegisterElectionHandlerFromEndpoint is same as RegisterElectionHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterElectionHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterElectionHandler(ctx, mux, conn)
+}
+
+// RegisterElectionHandler registers the http handlers for service Election to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterElectionHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterElectionHandlerClient(ctx, mux, v3electionpb.NewElectionClient(conn))
+}
+
+// RegisterElectionHandler registers the http handlers for service Election to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "ElectionClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "ElectionClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "ElectionClient" to call the correct interceptors.
+func RegisterElectionHandlerClient(ctx context.Context, mux *runtime.ServeMux, client v3electionpb.ElectionClient) error {
+
+	mux.Handle("POST", pattern_Election_Campaign_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Election_Campaign_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Election_Campaign_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Election_Proclaim_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Election_Proclaim_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Election_Proclaim_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Election_Leader_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Election_Leader_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Election_Leader_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Election_Observe_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Election_Observe_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Election_Observe_0(ctx, mux, outboundMarshaler, w, req, func() (proto.Message, error) { return resp.Recv() }, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Election_Resign_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Election_Resign_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Election_Resign_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Election_Campaign_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "election", "campaign"}, ""))
+
+	pattern_Election_Proclaim_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "election", "proclaim"}, ""))
+
+	pattern_Election_Leader_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "election", "leader"}, ""))
+
+	pattern_Election_Observe_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "election", "observe"}, ""))
+
+	pattern_Election_Resign_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "election", "resign"}, ""))
+)
+
+var (
+	forward_Election_Campaign_0 = runtime.ForwardResponseMessage
+
+	forward_Election_Proclaim_0 = runtime.ForwardResponseMessage
+
+	forward_Election_Leader_0 = runtime.ForwardResponseMessage
+
+	forward_Election_Observe_0 = runtime.ForwardResponseStream
+
+	forward_Election_Resign_0 = runtime.ForwardResponseMessage
+)
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.pb.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.pb.go
new file mode 100644
index 0000000..1fc1bce
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.pb.go
@@ -0,0 +1,2079 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: v3election.proto
+
+/*
+	Package v3electionpb is a generated protocol buffer package.
+
+	It is generated from these files:
+		v3election.proto
+
+	It has these top-level messages:
+		CampaignRequest
+		CampaignResponse
+		LeaderKey
+		LeaderRequest
+		LeaderResponse
+		ResignRequest
+		ResignResponse
+		ProclaimRequest
+		ProclaimResponse
+*/
+package v3electionpb
+
+import (
+	"fmt"
+
+	proto "github.com/golang/protobuf/proto"
+
+	math "math"
+
+	_ "github.com/gogo/protobuf/gogoproto"
+
+	etcdserverpb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	mvccpb "go.etcd.io/etcd/mvcc/mvccpb"
+
+	context "golang.org/x/net/context"
+
+	grpc "google.golang.org/grpc"
+
+	io "io"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type CampaignRequest struct {
+	// name is the election's identifier for the campaign.
+	Name []byte `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	// lease is the ID of the lease attached to leadership of the election. If the
+	// lease expires or is revoked before resigning leadership, then the
+	// leadership is transferred to the next campaigner, if any.
+	Lease int64 `protobuf:"varint,2,opt,name=lease,proto3" json:"lease,omitempty"`
+	// value is the initial proclaimed value set when the campaigner wins the
+	// election.
+	Value []byte `protobuf:"bytes,3,opt,name=value,proto3" json:"value,omitempty"`
+}
+
+func (m *CampaignRequest) Reset()                    { *m = CampaignRequest{} }
+func (m *CampaignRequest) String() string            { return proto.CompactTextString(m) }
+func (*CampaignRequest) ProtoMessage()               {}
+func (*CampaignRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{0} }
+
+func (m *CampaignRequest) GetName() []byte {
+	if m != nil {
+		return m.Name
+	}
+	return nil
+}
+
+func (m *CampaignRequest) GetLease() int64 {
+	if m != nil {
+		return m.Lease
+	}
+	return 0
+}
+
+func (m *CampaignRequest) GetValue() []byte {
+	if m != nil {
+		return m.Value
+	}
+	return nil
+}
+
+type CampaignResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+	// leader describes the resources used for holding leadereship of the election.
+	Leader *LeaderKey `protobuf:"bytes,2,opt,name=leader" json:"leader,omitempty"`
+}
+
+func (m *CampaignResponse) Reset()                    { *m = CampaignResponse{} }
+func (m *CampaignResponse) String() string            { return proto.CompactTextString(m) }
+func (*CampaignResponse) ProtoMessage()               {}
+func (*CampaignResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{1} }
+
+func (m *CampaignResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+func (m *CampaignResponse) GetLeader() *LeaderKey {
+	if m != nil {
+		return m.Leader
+	}
+	return nil
+}
+
+type LeaderKey struct {
+	// name is the election identifier that correponds to the leadership key.
+	Name []byte `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	// key is an opaque key representing the ownership of the election. If the key
+	// is deleted, then leadership is lost.
+	Key []byte `protobuf:"bytes,2,opt,name=key,proto3" json:"key,omitempty"`
+	// rev is the creation revision of the key. It can be used to test for ownership
+	// of an election during transactions by testing the key's creation revision
+	// matches rev.
+	Rev int64 `protobuf:"varint,3,opt,name=rev,proto3" json:"rev,omitempty"`
+	// lease is the lease ID of the election leader.
+	Lease int64 `protobuf:"varint,4,opt,name=lease,proto3" json:"lease,omitempty"`
+}
+
+func (m *LeaderKey) Reset()                    { *m = LeaderKey{} }
+func (m *LeaderKey) String() string            { return proto.CompactTextString(m) }
+func (*LeaderKey) ProtoMessage()               {}
+func (*LeaderKey) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{2} }
+
+func (m *LeaderKey) GetName() []byte {
+	if m != nil {
+		return m.Name
+	}
+	return nil
+}
+
+func (m *LeaderKey) GetKey() []byte {
+	if m != nil {
+		return m.Key
+	}
+	return nil
+}
+
+func (m *LeaderKey) GetRev() int64 {
+	if m != nil {
+		return m.Rev
+	}
+	return 0
+}
+
+func (m *LeaderKey) GetLease() int64 {
+	if m != nil {
+		return m.Lease
+	}
+	return 0
+}
+
+type LeaderRequest struct {
+	// name is the election identifier for the leadership information.
+	Name []byte `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+}
+
+func (m *LeaderRequest) Reset()                    { *m = LeaderRequest{} }
+func (m *LeaderRequest) String() string            { return proto.CompactTextString(m) }
+func (*LeaderRequest) ProtoMessage()               {}
+func (*LeaderRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{3} }
+
+func (m *LeaderRequest) GetName() []byte {
+	if m != nil {
+		return m.Name
+	}
+	return nil
+}
+
+type LeaderResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+	// kv is the key-value pair representing the latest leader update.
+	Kv *mvccpb.KeyValue `protobuf:"bytes,2,opt,name=kv" json:"kv,omitempty"`
+}
+
+func (m *LeaderResponse) Reset()                    { *m = LeaderResponse{} }
+func (m *LeaderResponse) String() string            { return proto.CompactTextString(m) }
+func (*LeaderResponse) ProtoMessage()               {}
+func (*LeaderResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{4} }
+
+func (m *LeaderResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+func (m *LeaderResponse) GetKv() *mvccpb.KeyValue {
+	if m != nil {
+		return m.Kv
+	}
+	return nil
+}
+
+type ResignRequest struct {
+	// leader is the leadership to relinquish by resignation.
+	Leader *LeaderKey `protobuf:"bytes,1,opt,name=leader" json:"leader,omitempty"`
+}
+
+func (m *ResignRequest) Reset()                    { *m = ResignRequest{} }
+func (m *ResignRequest) String() string            { return proto.CompactTextString(m) }
+func (*ResignRequest) ProtoMessage()               {}
+func (*ResignRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{5} }
+
+func (m *ResignRequest) GetLeader() *LeaderKey {
+	if m != nil {
+		return m.Leader
+	}
+	return nil
+}
+
+type ResignResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+}
+
+func (m *ResignResponse) Reset()                    { *m = ResignResponse{} }
+func (m *ResignResponse) String() string            { return proto.CompactTextString(m) }
+func (*ResignResponse) ProtoMessage()               {}
+func (*ResignResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{6} }
+
+func (m *ResignResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+type ProclaimRequest struct {
+	// leader is the leadership hold on the election.
+	Leader *LeaderKey `protobuf:"bytes,1,opt,name=leader" json:"leader,omitempty"`
+	// value is an update meant to overwrite the leader's current value.
+	Value []byte `protobuf:"bytes,2,opt,name=value,proto3" json:"value,omitempty"`
+}
+
+func (m *ProclaimRequest) Reset()                    { *m = ProclaimRequest{} }
+func (m *ProclaimRequest) String() string            { return proto.CompactTextString(m) }
+func (*ProclaimRequest) ProtoMessage()               {}
+func (*ProclaimRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{7} }
+
+func (m *ProclaimRequest) GetLeader() *LeaderKey {
+	if m != nil {
+		return m.Leader
+	}
+	return nil
+}
+
+func (m *ProclaimRequest) GetValue() []byte {
+	if m != nil {
+		return m.Value
+	}
+	return nil
+}
+
+type ProclaimResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+}
+
+func (m *ProclaimResponse) Reset()                    { *m = ProclaimResponse{} }
+func (m *ProclaimResponse) String() string            { return proto.CompactTextString(m) }
+func (*ProclaimResponse) ProtoMessage()               {}
+func (*ProclaimResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Election, []int{8} }
+
+func (m *ProclaimResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*CampaignRequest)(nil), "v3electionpb.CampaignRequest")
+	proto.RegisterType((*CampaignResponse)(nil), "v3electionpb.CampaignResponse")
+	proto.RegisterType((*LeaderKey)(nil), "v3electionpb.LeaderKey")
+	proto.RegisterType((*LeaderRequest)(nil), "v3electionpb.LeaderRequest")
+	proto.RegisterType((*LeaderResponse)(nil), "v3electionpb.LeaderResponse")
+	proto.RegisterType((*ResignRequest)(nil), "v3electionpb.ResignRequest")
+	proto.RegisterType((*ResignResponse)(nil), "v3electionpb.ResignResponse")
+	proto.RegisterType((*ProclaimRequest)(nil), "v3electionpb.ProclaimRequest")
+	proto.RegisterType((*ProclaimResponse)(nil), "v3electionpb.ProclaimResponse")
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// Client API for Election service
+
+type ElectionClient interface {
+	// Campaign waits to acquire leadership in an election, returning a LeaderKey
+	// representing the leadership if successful. The LeaderKey can then be used
+	// to issue new values on the election, transactionally guard API requests on
+	// leadership still being held, and resign from the election.
+	Campaign(ctx context.Context, in *CampaignRequest, opts ...grpc.CallOption) (*CampaignResponse, error)
+	// Proclaim updates the leader's posted value with a new value.
+	Proclaim(ctx context.Context, in *ProclaimRequest, opts ...grpc.CallOption) (*ProclaimResponse, error)
+	// Leader returns the current election proclamation, if any.
+	Leader(ctx context.Context, in *LeaderRequest, opts ...grpc.CallOption) (*LeaderResponse, error)
+	// Observe streams election proclamations in-order as made by the election's
+	// elected leaders.
+	Observe(ctx context.Context, in *LeaderRequest, opts ...grpc.CallOption) (Election_ObserveClient, error)
+	// Resign releases election leadership so other campaigners may acquire
+	// leadership on the election.
+	Resign(ctx context.Context, in *ResignRequest, opts ...grpc.CallOption) (*ResignResponse, error)
+}
+
+type electionClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewElectionClient(cc *grpc.ClientConn) ElectionClient {
+	return &electionClient{cc}
+}
+
+func (c *electionClient) Campaign(ctx context.Context, in *CampaignRequest, opts ...grpc.CallOption) (*CampaignResponse, error) {
+	out := new(CampaignResponse)
+	err := grpc.Invoke(ctx, "/v3electionpb.Election/Campaign", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *electionClient) Proclaim(ctx context.Context, in *ProclaimRequest, opts ...grpc.CallOption) (*ProclaimResponse, error) {
+	out := new(ProclaimResponse)
+	err := grpc.Invoke(ctx, "/v3electionpb.Election/Proclaim", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *electionClient) Leader(ctx context.Context, in *LeaderRequest, opts ...grpc.CallOption) (*LeaderResponse, error) {
+	out := new(LeaderResponse)
+	err := grpc.Invoke(ctx, "/v3electionpb.Election/Leader", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *electionClient) Observe(ctx context.Context, in *LeaderRequest, opts ...grpc.CallOption) (Election_ObserveClient, error) {
+	stream, err := grpc.NewClientStream(ctx, &_Election_serviceDesc.Streams[0], c.cc, "/v3electionpb.Election/Observe", opts...)
+	if err != nil {
+		return nil, err
+	}
+	x := &electionObserveClient{stream}
+	if err := x.ClientStream.SendMsg(in); err != nil {
+		return nil, err
+	}
+	if err := x.ClientStream.CloseSend(); err != nil {
+		return nil, err
+	}
+	return x, nil
+}
+
+type Election_ObserveClient interface {
+	Recv() (*LeaderResponse, error)
+	grpc.ClientStream
+}
+
+type electionObserveClient struct {
+	grpc.ClientStream
+}
+
+func (x *electionObserveClient) Recv() (*LeaderResponse, error) {
+	m := new(LeaderResponse)
+	if err := x.ClientStream.RecvMsg(m); err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func (c *electionClient) Resign(ctx context.Context, in *ResignRequest, opts ...grpc.CallOption) (*ResignResponse, error) {
+	out := new(ResignResponse)
+	err := grpc.Invoke(ctx, "/v3electionpb.Election/Resign", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for Election service
+
+type ElectionServer interface {
+	// Campaign waits to acquire leadership in an election, returning a LeaderKey
+	// representing the leadership if successful. The LeaderKey can then be used
+	// to issue new values on the election, transactionally guard API requests on
+	// leadership still being held, and resign from the election.
+	Campaign(context.Context, *CampaignRequest) (*CampaignResponse, error)
+	// Proclaim updates the leader's posted value with a new value.
+	Proclaim(context.Context, *ProclaimRequest) (*ProclaimResponse, error)
+	// Leader returns the current election proclamation, if any.
+	Leader(context.Context, *LeaderRequest) (*LeaderResponse, error)
+	// Observe streams election proclamations in-order as made by the election's
+	// elected leaders.
+	Observe(*LeaderRequest, Election_ObserveServer) error
+	// Resign releases election leadership so other campaigners may acquire
+	// leadership on the election.
+	Resign(context.Context, *ResignRequest) (*ResignResponse, error)
+}
+
+func RegisterElectionServer(s *grpc.Server, srv ElectionServer) {
+	s.RegisterService(&_Election_serviceDesc, srv)
+}
+
+func _Election_Campaign_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(CampaignRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ElectionServer).Campaign(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3electionpb.Election/Campaign",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ElectionServer).Campaign(ctx, req.(*CampaignRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _Election_Proclaim_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ProclaimRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ElectionServer).Proclaim(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3electionpb.Election/Proclaim",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ElectionServer).Proclaim(ctx, req.(*ProclaimRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _Election_Leader_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(LeaderRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ElectionServer).Leader(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3electionpb.Election/Leader",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ElectionServer).Leader(ctx, req.(*LeaderRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _Election_Observe_Handler(srv interface{}, stream grpc.ServerStream) error {
+	m := new(LeaderRequest)
+	if err := stream.RecvMsg(m); err != nil {
+		return err
+	}
+	return srv.(ElectionServer).Observe(m, &electionObserveServer{stream})
+}
+
+type Election_ObserveServer interface {
+	Send(*LeaderResponse) error
+	grpc.ServerStream
+}
+
+type electionObserveServer struct {
+	grpc.ServerStream
+}
+
+func (x *electionObserveServer) Send(m *LeaderResponse) error {
+	return x.ServerStream.SendMsg(m)
+}
+
+func _Election_Resign_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(ResignRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ElectionServer).Resign(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3electionpb.Election/Resign",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ElectionServer).Resign(ctx, req.(*ResignRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+var _Election_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "v3electionpb.Election",
+	HandlerType: (*ElectionServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "Campaign",
+			Handler:    _Election_Campaign_Handler,
+		},
+		{
+			MethodName: "Proclaim",
+			Handler:    _Election_Proclaim_Handler,
+		},
+		{
+			MethodName: "Leader",
+			Handler:    _Election_Leader_Handler,
+		},
+		{
+			MethodName: "Resign",
+			Handler:    _Election_Resign_Handler,
+		},
+	},
+	Streams: []grpc.StreamDesc{
+		{
+			StreamName:    "Observe",
+			Handler:       _Election_Observe_Handler,
+			ServerStreams: true,
+		},
+	},
+	Metadata: "v3election.proto",
+}
+
+func (m *CampaignRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *CampaignRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Name) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Name)))
+		i += copy(dAtA[i:], m.Name)
+	}
+	if m.Lease != 0 {
+		dAtA[i] = 0x10
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Lease))
+	}
+	if len(m.Value) > 0 {
+		dAtA[i] = 0x1a
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Value)))
+		i += copy(dAtA[i:], m.Value)
+	}
+	return i, nil
+}
+
+func (m *CampaignResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *CampaignResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Header.Size()))
+		n1, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n1
+	}
+	if m.Leader != nil {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Leader.Size()))
+		n2, err := m.Leader.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n2
+	}
+	return i, nil
+}
+
+func (m *LeaderKey) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LeaderKey) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Name) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Name)))
+		i += copy(dAtA[i:], m.Name)
+	}
+	if len(m.Key) > 0 {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Key)))
+		i += copy(dAtA[i:], m.Key)
+	}
+	if m.Rev != 0 {
+		dAtA[i] = 0x18
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Rev))
+	}
+	if m.Lease != 0 {
+		dAtA[i] = 0x20
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Lease))
+	}
+	return i, nil
+}
+
+func (m *LeaderRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LeaderRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Name) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Name)))
+		i += copy(dAtA[i:], m.Name)
+	}
+	return i, nil
+}
+
+func (m *LeaderResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LeaderResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Header.Size()))
+		n3, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n3
+	}
+	if m.Kv != nil {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Kv.Size()))
+		n4, err := m.Kv.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n4
+	}
+	return i, nil
+}
+
+func (m *ResignRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ResignRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Leader != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Leader.Size()))
+		n5, err := m.Leader.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n5
+	}
+	return i, nil
+}
+
+func (m *ResignResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ResignResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Header.Size()))
+		n6, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n6
+	}
+	return i, nil
+}
+
+func (m *ProclaimRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ProclaimRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Leader != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Leader.Size()))
+		n7, err := m.Leader.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n7
+	}
+	if len(m.Value) > 0 {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(len(m.Value)))
+		i += copy(dAtA[i:], m.Value)
+	}
+	return i, nil
+}
+
+func (m *ProclaimResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *ProclaimResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Election(dAtA, i, uint64(m.Header.Size()))
+		n8, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n8
+	}
+	return i, nil
+}
+
+func encodeVarintV3Election(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *CampaignRequest) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Name)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	if m.Lease != 0 {
+		n += 1 + sovV3Election(uint64(m.Lease))
+	}
+	l = len(m.Value)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *CampaignResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	if m.Leader != nil {
+		l = m.Leader.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *LeaderKey) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Name)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	l = len(m.Key)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	if m.Rev != 0 {
+		n += 1 + sovV3Election(uint64(m.Rev))
+	}
+	if m.Lease != 0 {
+		n += 1 + sovV3Election(uint64(m.Lease))
+	}
+	return n
+}
+
+func (m *LeaderRequest) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Name)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *LeaderResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	if m.Kv != nil {
+		l = m.Kv.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *ResignRequest) Size() (n int) {
+	var l int
+	_ = l
+	if m.Leader != nil {
+		l = m.Leader.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *ResignResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *ProclaimRequest) Size() (n int) {
+	var l int
+	_ = l
+	if m.Leader != nil {
+		l = m.Leader.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	l = len(m.Value)
+	if l > 0 {
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func (m *ProclaimResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Election(uint64(l))
+	}
+	return n
+}
+
+func sovV3Election(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozV3Election(x uint64) (n int) {
+	return sovV3Election(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *CampaignRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: CampaignRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: CampaignRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Name", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Name = append(m.Name[:0], dAtA[iNdEx:postIndex]...)
+			if m.Name == nil {
+				m.Name = []byte{}
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Lease", wireType)
+			}
+			m.Lease = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Lease |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 3:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Value", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Value = append(m.Value[:0], dAtA[iNdEx:postIndex]...)
+			if m.Value == nil {
+				m.Value = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *CampaignResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: CampaignResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: CampaignResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Leader", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Leader == nil {
+				m.Leader = &LeaderKey{}
+			}
+			if err := m.Leader.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LeaderKey) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LeaderKey: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LeaderKey: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Name", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Name = append(m.Name[:0], dAtA[iNdEx:postIndex]...)
+			if m.Name == nil {
+				m.Name = []byte{}
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Key", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Key = append(m.Key[:0], dAtA[iNdEx:postIndex]...)
+			if m.Key == nil {
+				m.Key = []byte{}
+			}
+			iNdEx = postIndex
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Rev", wireType)
+			}
+			m.Rev = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Rev |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 4:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Lease", wireType)
+			}
+			m.Lease = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Lease |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LeaderRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LeaderRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LeaderRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Name", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Name = append(m.Name[:0], dAtA[iNdEx:postIndex]...)
+			if m.Name == nil {
+				m.Name = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LeaderResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LeaderResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LeaderResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Kv", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Kv == nil {
+				m.Kv = &mvccpb.KeyValue{}
+			}
+			if err := m.Kv.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *ResignRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ResignRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ResignRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Leader", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Leader == nil {
+				m.Leader = &LeaderKey{}
+			}
+			if err := m.Leader.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *ResignResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ResignResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ResignResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *ProclaimRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ProclaimRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ProclaimRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Leader", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Leader == nil {
+				m.Leader = &LeaderKey{}
+			}
+			if err := m.Leader.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Value", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Value = append(m.Value[:0], dAtA[iNdEx:postIndex]...)
+			if m.Value == nil {
+				m.Value = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *ProclaimResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: ProclaimResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: ProclaimResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Election(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Election
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipV3Election(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowV3Election
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowV3Election
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthV3Election
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowV3Election
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipV3Election(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthV3Election = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowV3Election   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("v3election.proto", fileDescriptorV3Election) }
+
+var fileDescriptorV3Election = []byte{
+	// 535 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xa4, 0x94, 0xcf, 0x6e, 0xd3, 0x40,
+	0x10, 0xc6, 0x59, 0x27, 0x84, 0x32, 0xa4, 0xad, 0x65, 0x82, 0x48, 0x43, 0x30, 0xd1, 0x22, 0xa1,
+	0x2a, 0x07, 0x2f, 0x6a, 0x38, 0xe5, 0x84, 0x40, 0xa0, 0x4a, 0x45, 0x02, 0x7c, 0x40, 0x70, 0xdc,
+	0xb8, 0x23, 0x37, 0x8a, 0xe3, 0x35, 0xb6, 0x6b, 0x29, 0x57, 0x5e, 0x81, 0x03, 0x3c, 0x12, 0x47,
+	0x24, 0x5e, 0x00, 0x05, 0x1e, 0x04, 0xed, 0xae, 0x8d, 0xff, 0x28, 0x41, 0xa8, 0xb9, 0x58, 0xe3,
+	0x9d, 0xcf, 0xf3, 0x9b, 0x6f, 0x76, 0x12, 0x30, 0xb3, 0x09, 0x06, 0xe8, 0xa5, 0x73, 0x11, 0x3a,
+	0x51, 0x2c, 0x52, 0x61, 0x75, 0xcb, 0x93, 0x68, 0x36, 0xe8, 0xf9, 0xc2, 0x17, 0x2a, 0xc1, 0x64,
+	0xa4, 0x35, 0x83, 0x47, 0x98, 0x7a, 0xe7, 0x4c, 0x3e, 0x12, 0x8c, 0x33, 0x8c, 0x2b, 0x61, 0x34,
+	0x63, 0x71, 0xe4, 0xe5, 0xba, 0x23, 0xa5, 0x5b, 0x66, 0x9e, 0xa7, 0x1e, 0xd1, 0x8c, 0x2d, 0xb2,
+	0x3c, 0x35, 0xf4, 0x85, 0xf0, 0x03, 0x64, 0x3c, 0x9a, 0x33, 0x1e, 0x86, 0x22, 0xe5, 0x92, 0x98,
+	0xe8, 0x2c, 0x7d, 0x0b, 0x87, 0xcf, 0xf9, 0x32, 0xe2, 0x73, 0x3f, 0x74, 0xf1, 0xe3, 0x25, 0x26,
+	0xa9, 0x65, 0x41, 0x3b, 0xe4, 0x4b, 0xec, 0x93, 0x11, 0x39, 0xee, 0xba, 0x2a, 0xb6, 0x7a, 0x70,
+	0x3d, 0x40, 0x9e, 0x60, 0xdf, 0x18, 0x91, 0xe3, 0x96, 0xab, 0x5f, 0xe4, 0x69, 0xc6, 0x83, 0x4b,
+	0xec, 0xb7, 0x94, 0x54, 0xbf, 0xd0, 0x15, 0x98, 0x65, 0xc9, 0x24, 0x12, 0x61, 0x82, 0xd6, 0x13,
+	0xe8, 0x5c, 0x20, 0x3f, 0xc7, 0x58, 0x55, 0xbd, 0x75, 0x32, 0x74, 0xaa, 0x46, 0x9c, 0x42, 0x77,
+	0xaa, 0x34, 0x6e, 0xae, 0xb5, 0x18, 0x74, 0x02, 0xfd, 0x95, 0xa1, 0xbe, 0xba, 0xeb, 0x54, 0x47,
+	0xe6, 0xbc, 0x52, 0xb9, 0x33, 0x5c, 0xb9, 0xb9, 0x8c, 0x7e, 0x80, 0x9b, 0x7f, 0x0f, 0x37, 0xfa,
+	0x30, 0xa1, 0xb5, 0xc0, 0x95, 0x2a, 0xd7, 0x75, 0x65, 0x28, 0x4f, 0x62, 0xcc, 0x94, 0x83, 0x96,
+	0x2b, 0xc3, 0xd2, 0x6b, 0xbb, 0xe2, 0x95, 0x3e, 0x84, 0x7d, 0x5d, 0xfa, 0x1f, 0x63, 0xa2, 0x17,
+	0x70, 0x50, 0x88, 0x76, 0x32, 0x3e, 0x02, 0x63, 0x91, 0xe5, 0xa6, 0x4d, 0x47, 0xdf, 0xa8, 0x73,
+	0x86, 0xab, 0x77, 0x72, 0xc0, 0xae, 0xb1, 0xc8, 0xe8, 0x53, 0xd8, 0x77, 0x31, 0xa9, 0xdc, 0x5a,
+	0x39, 0x2b, 0xf2, 0x7f, 0xb3, 0x7a, 0x09, 0x07, 0x45, 0x85, 0x5d, 0x7a, 0xa5, 0xef, 0xe1, 0xf0,
+	0x4d, 0x2c, 0xbc, 0x80, 0xcf, 0x97, 0x57, 0xed, 0xa5, 0x5c, 0x24, 0xa3, 0xba, 0x48, 0xa7, 0x60,
+	0x96, 0x95, 0x77, 0xe9, 0xf1, 0xe4, 0x4b, 0x1b, 0xf6, 0x5e, 0xe4, 0x0d, 0x58, 0x0b, 0xd8, 0x2b,
+	0xf6, 0xd3, 0xba, 0x5f, 0xef, 0xac, 0xf1, 0x53, 0x18, 0xd8, 0xdb, 0xd2, 0x9a, 0x42, 0x47, 0x9f,
+	0x7e, 0xfc, 0xfe, 0x6c, 0x0c, 0xe8, 0x1d, 0x96, 0x4d, 0x58, 0x21, 0x64, 0x5e, 0x2e, 0x9b, 0x92,
+	0xb1, 0x84, 0x15, 0x1e, 0x9a, 0xb0, 0xc6, 0xd4, 0x9a, 0xb0, 0xa6, 0xf5, 0x2d, 0xb0, 0x28, 0x97,
+	0x49, 0x98, 0x07, 0x1d, 0x3d, 0x5b, 0xeb, 0xde, 0xa6, 0x89, 0x17, 0xa0, 0xe1, 0xe6, 0x64, 0x8e,
+	0xb1, 0x15, 0xa6, 0x4f, 0x6f, 0xd7, 0x30, 0xfa, 0xa2, 0x24, 0xc4, 0x87, 0x1b, 0xaf, 0x67, 0x6a,
+	0xe0, 0xbb, 0x50, 0x1e, 0x28, 0xca, 0x11, 0xed, 0xd5, 0x28, 0x42, 0x17, 0x9e, 0x92, 0xf1, 0x63,
+	0x22, 0xdd, 0xe8, 0x05, 0x6d, 0x72, 0x6a, 0x8b, 0xdf, 0xe4, 0xd4, 0x77, 0x7a, 0x8b, 0x9b, 0x58,
+	0x89, 0xa6, 0x64, 0xfc, 0xcc, 0xfc, 0xb6, 0xb6, 0xc9, 0xf7, 0xb5, 0x4d, 0x7e, 0xae, 0x6d, 0xf2,
+	0xf5, 0x97, 0x7d, 0x6d, 0xd6, 0x51, 0x7f, 0x8c, 0x93, 0x3f, 0x01, 0x00, 0x00, 0xff, 0xff, 0x2f,
+	0x1d, 0xfa, 0x11, 0xb1, 0x05, 0x00, 0x00,
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.proto b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.proto
new file mode 100644
index 0000000..918f39f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb/v3election.proto
@@ -0,0 +1,119 @@
+syntax = "proto3";
+package v3electionpb;
+
+import "gogoproto/gogo.proto";
+import "etcd/etcdserver/etcdserverpb/rpc.proto";
+import "etcd/mvcc/mvccpb/kv.proto";
+
+// for grpc-gateway
+import "google/api/annotations.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+
+// The election service exposes client-side election facilities as a gRPC interface.
+service Election {
+  // Campaign waits to acquire leadership in an election, returning a LeaderKey
+  // representing the leadership if successful. The LeaderKey can then be used
+  // to issue new values on the election, transactionally guard API requests on
+  // leadership still being held, and resign from the election.
+  rpc Campaign(CampaignRequest) returns (CampaignResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/campaign"
+        body: "*"
+    };
+  }
+  // Proclaim updates the leader's posted value with a new value.
+  rpc Proclaim(ProclaimRequest) returns (ProclaimResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/proclaim"
+        body: "*"
+    };
+  }
+  // Leader returns the current election proclamation, if any.
+  rpc Leader(LeaderRequest) returns (LeaderResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/leader"
+        body: "*"
+    };
+  }
+  // Observe streams election proclamations in-order as made by the election's
+  // elected leaders.
+  rpc Observe(LeaderRequest) returns (stream LeaderResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/observe"
+        body: "*"
+    };
+  }
+  // Resign releases election leadership so other campaigners may acquire
+  // leadership on the election.
+  rpc Resign(ResignRequest) returns (ResignResponse) {
+      option (google.api.http) = {
+        post: "/v3/election/resign"
+        body: "*"
+    };
+  }
+}
+
+message CampaignRequest {
+  // name is the election's identifier for the campaign.
+  bytes name = 1;
+  // lease is the ID of the lease attached to leadership of the election. If the
+  // lease expires or is revoked before resigning leadership, then the
+  // leadership is transferred to the next campaigner, if any.
+  int64 lease = 2;
+  // value is the initial proclaimed value set when the campaigner wins the
+  // election.
+  bytes value = 3;
+}
+
+message CampaignResponse {
+  etcdserverpb.ResponseHeader header = 1;
+  // leader describes the resources used for holding leadereship of the election.
+  LeaderKey leader = 2;
+}
+
+message LeaderKey {
+  // name is the election identifier that correponds to the leadership key.
+  bytes name = 1;
+  // key is an opaque key representing the ownership of the election. If the key
+  // is deleted, then leadership is lost.
+  bytes key = 2;
+  // rev is the creation revision of the key. It can be used to test for ownership
+  // of an election during transactions by testing the key's creation revision
+  // matches rev.
+  int64 rev = 3;
+  // lease is the lease ID of the election leader.
+  int64 lease = 4;
+}
+
+message LeaderRequest {
+  // name is the election identifier for the leadership information.
+  bytes name = 1;
+}
+
+message LeaderResponse {
+  etcdserverpb.ResponseHeader header = 1;
+  // kv is the key-value pair representing the latest leader update.
+  mvccpb.KeyValue kv = 2;
+}
+
+message ResignRequest {
+  // leader is the leadership to relinquish by resignation.
+  LeaderKey leader = 1;
+}
+
+message ResignResponse {
+  etcdserverpb.ResponseHeader header = 1;
+}
+
+message ProclaimRequest {
+  // leader is the leadership hold on the election.
+  LeaderKey leader = 1;
+  // value is an update meant to overwrite the leader's current value.
+  bytes value = 2;
+}
+
+message ProclaimResponse {
+  etcdserverpb.ResponseHeader header = 1;
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/doc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/doc.go
new file mode 100644
index 0000000..e0a1008
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3lock provides a v3 locking service from an etcdserver.
+package v3lock
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/lock.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/lock.go
new file mode 100644
index 0000000..5a17c86
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/lock.go
@@ -0,0 +1,56 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3lock
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/clientv3/concurrency"
+	"go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb"
+)
+
+type lockServer struct {
+	c *clientv3.Client
+}
+
+func NewLockServer(c *clientv3.Client) v3lockpb.LockServer {
+	return &lockServer{c}
+}
+
+func (ls *lockServer) Lock(ctx context.Context, req *v3lockpb.LockRequest) (*v3lockpb.LockResponse, error) {
+	s, err := concurrency.NewSession(
+		ls.c,
+		concurrency.WithLease(clientv3.LeaseID(req.Lease)),
+		concurrency.WithContext(ctx),
+	)
+	if err != nil {
+		return nil, err
+	}
+	s.Orphan()
+	m := concurrency.NewMutex(s, string(req.Name))
+	if err = m.Lock(ctx); err != nil {
+		return nil, err
+	}
+	return &v3lockpb.LockResponse{Header: m.Header(), Key: []byte(m.Key())}, nil
+}
+
+func (ls *lockServer) Unlock(ctx context.Context, req *v3lockpb.UnlockRequest) (*v3lockpb.UnlockResponse, error) {
+	resp, err := ls.c.Delete(ctx, string(req.Key))
+	if err != nil {
+		return nil, err
+	}
+	return &v3lockpb.UnlockResponse{Header: resp.Header}, nil
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/gw/v3lock.pb.gw.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/gw/v3lock.pb.gw.go
new file mode 100644
index 0000000..1eeeff1
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/gw/v3lock.pb.gw.go
@@ -0,0 +1,167 @@
+// Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
+// source: etcdserver/api/v3lock/v3lockpb/v3lock.proto
+
+/*
+Package v3lockpb is a reverse proxy.
+
+It translates gRPC into RESTful JSON APIs.
+*/
+package gw
+
+import (
+	"go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+var _ codes.Code
+var _ io.Reader
+var _ status.Status
+var _ = runtime.String
+var _ = utilities.NewDoubleArray
+
+func request_Lock_Lock_0(ctx context.Context, marshaler runtime.Marshaler, client v3lockpb.LockClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3lockpb.LockRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Lock(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lock_Unlock_0(ctx context.Context, marshaler runtime.Marshaler, client v3lockpb.LockClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq v3lockpb.UnlockRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Unlock(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+// RegisterLockHandlerFromEndpoint is same as RegisterLockHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterLockHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterLockHandler(ctx, mux, conn)
+}
+
+// RegisterLockHandler registers the http handlers for service Lock to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterLockHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterLockHandlerClient(ctx, mux, v3lockpb.NewLockClient(conn))
+}
+
+// RegisterLockHandler registers the http handlers for service Lock to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "LockClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "LockClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "LockClient" to call the correct interceptors.
+func RegisterLockHandlerClient(ctx context.Context, mux *runtime.ServeMux, client v3lockpb.LockClient) error {
+
+	mux.Handle("POST", pattern_Lock_Lock_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lock_Lock_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lock_Lock_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lock_Unlock_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lock_Unlock_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lock_Unlock_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Lock_Lock_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 1}, []string{"v3", "lock"}, ""))
+
+	pattern_Lock_Unlock_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lock", "unlock"}, ""))
+)
+
+var (
+	forward_Lock_Lock_0 = runtime.ForwardResponseMessage
+
+	forward_Lock_Unlock_0 = runtime.ForwardResponseMessage
+)
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.pb.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.pb.go
new file mode 100644
index 0000000..36ebdd9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.pb.go
@@ -0,0 +1,959 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: v3lock.proto
+
+/*
+	Package v3lockpb is a generated protocol buffer package.
+
+	It is generated from these files:
+		v3lock.proto
+
+	It has these top-level messages:
+		LockRequest
+		LockResponse
+		UnlockRequest
+		UnlockResponse
+*/
+package v3lockpb
+
+import (
+	"fmt"
+
+	proto "github.com/golang/protobuf/proto"
+
+	math "math"
+
+	_ "github.com/gogo/protobuf/gogoproto"
+
+	etcdserverpb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	context "golang.org/x/net/context"
+
+	grpc "google.golang.org/grpc"
+
+	io "io"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type LockRequest struct {
+	// name is the identifier for the distributed shared lock to be acquired.
+	Name []byte `protobuf:"bytes,1,opt,name=name,proto3" json:"name,omitempty"`
+	// lease is the ID of the lease that will be attached to ownership of the
+	// lock. If the lease expires or is revoked and currently holds the lock,
+	// the lock is automatically released. Calls to Lock with the same lease will
+	// be treated as a single acquisition; locking twice with the same lease is a
+	// no-op.
+	Lease int64 `protobuf:"varint,2,opt,name=lease,proto3" json:"lease,omitempty"`
+}
+
+func (m *LockRequest) Reset()                    { *m = LockRequest{} }
+func (m *LockRequest) String() string            { return proto.CompactTextString(m) }
+func (*LockRequest) ProtoMessage()               {}
+func (*LockRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Lock, []int{0} }
+
+func (m *LockRequest) GetName() []byte {
+	if m != nil {
+		return m.Name
+	}
+	return nil
+}
+
+func (m *LockRequest) GetLease() int64 {
+	if m != nil {
+		return m.Lease
+	}
+	return 0
+}
+
+type LockResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+	// key is a key that will exist on etcd for the duration that the Lock caller
+	// owns the lock. Users should not modify this key or the lock may exhibit
+	// undefined behavior.
+	Key []byte `protobuf:"bytes,2,opt,name=key,proto3" json:"key,omitempty"`
+}
+
+func (m *LockResponse) Reset()                    { *m = LockResponse{} }
+func (m *LockResponse) String() string            { return proto.CompactTextString(m) }
+func (*LockResponse) ProtoMessage()               {}
+func (*LockResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Lock, []int{1} }
+
+func (m *LockResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+func (m *LockResponse) GetKey() []byte {
+	if m != nil {
+		return m.Key
+	}
+	return nil
+}
+
+type UnlockRequest struct {
+	// key is the lock ownership key granted by Lock.
+	Key []byte `protobuf:"bytes,1,opt,name=key,proto3" json:"key,omitempty"`
+}
+
+func (m *UnlockRequest) Reset()                    { *m = UnlockRequest{} }
+func (m *UnlockRequest) String() string            { return proto.CompactTextString(m) }
+func (*UnlockRequest) ProtoMessage()               {}
+func (*UnlockRequest) Descriptor() ([]byte, []int) { return fileDescriptorV3Lock, []int{2} }
+
+func (m *UnlockRequest) GetKey() []byte {
+	if m != nil {
+		return m.Key
+	}
+	return nil
+}
+
+type UnlockResponse struct {
+	Header *etcdserverpb.ResponseHeader `protobuf:"bytes,1,opt,name=header" json:"header,omitempty"`
+}
+
+func (m *UnlockResponse) Reset()                    { *m = UnlockResponse{} }
+func (m *UnlockResponse) String() string            { return proto.CompactTextString(m) }
+func (*UnlockResponse) ProtoMessage()               {}
+func (*UnlockResponse) Descriptor() ([]byte, []int) { return fileDescriptorV3Lock, []int{3} }
+
+func (m *UnlockResponse) GetHeader() *etcdserverpb.ResponseHeader {
+	if m != nil {
+		return m.Header
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*LockRequest)(nil), "v3lockpb.LockRequest")
+	proto.RegisterType((*LockResponse)(nil), "v3lockpb.LockResponse")
+	proto.RegisterType((*UnlockRequest)(nil), "v3lockpb.UnlockRequest")
+	proto.RegisterType((*UnlockResponse)(nil), "v3lockpb.UnlockResponse")
+}
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ context.Context
+var _ grpc.ClientConn
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+const _ = grpc.SupportPackageIsVersion4
+
+// Client API for Lock service
+
+type LockClient interface {
+	// Lock acquires a distributed shared lock on a given named lock.
+	// On success, it will return a unique key that exists so long as the
+	// lock is held by the caller. This key can be used in conjunction with
+	// transactions to safely ensure updates to etcd only occur while holding
+	// lock ownership. The lock is held until Unlock is called on the key or the
+	// lease associate with the owner expires.
+	Lock(ctx context.Context, in *LockRequest, opts ...grpc.CallOption) (*LockResponse, error)
+	// Unlock takes a key returned by Lock and releases the hold on lock. The
+	// next Lock caller waiting for the lock will then be woken up and given
+	// ownership of the lock.
+	Unlock(ctx context.Context, in *UnlockRequest, opts ...grpc.CallOption) (*UnlockResponse, error)
+}
+
+type lockClient struct {
+	cc *grpc.ClientConn
+}
+
+func NewLockClient(cc *grpc.ClientConn) LockClient {
+	return &lockClient{cc}
+}
+
+func (c *lockClient) Lock(ctx context.Context, in *LockRequest, opts ...grpc.CallOption) (*LockResponse, error) {
+	out := new(LockResponse)
+	err := grpc.Invoke(ctx, "/v3lockpb.Lock/Lock", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+func (c *lockClient) Unlock(ctx context.Context, in *UnlockRequest, opts ...grpc.CallOption) (*UnlockResponse, error) {
+	out := new(UnlockResponse)
+	err := grpc.Invoke(ctx, "/v3lockpb.Lock/Unlock", in, out, c.cc, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Server API for Lock service
+
+type LockServer interface {
+	// Lock acquires a distributed shared lock on a given named lock.
+	// On success, it will return a unique key that exists so long as the
+	// lock is held by the caller. This key can be used in conjunction with
+	// transactions to safely ensure updates to etcd only occur while holding
+	// lock ownership. The lock is held until Unlock is called on the key or the
+	// lease associate with the owner expires.
+	Lock(context.Context, *LockRequest) (*LockResponse, error)
+	// Unlock takes a key returned by Lock and releases the hold on lock. The
+	// next Lock caller waiting for the lock will then be woken up and given
+	// ownership of the lock.
+	Unlock(context.Context, *UnlockRequest) (*UnlockResponse, error)
+}
+
+func RegisterLockServer(s *grpc.Server, srv LockServer) {
+	s.RegisterService(&_Lock_serviceDesc, srv)
+}
+
+func _Lock_Lock_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(LockRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(LockServer).Lock(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3lockpb.Lock/Lock",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(LockServer).Lock(ctx, req.(*LockRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+func _Lock_Unlock_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(UnlockRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(LockServer).Unlock(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/v3lockpb.Lock/Unlock",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(LockServer).Unlock(ctx, req.(*UnlockRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+var _Lock_serviceDesc = grpc.ServiceDesc{
+	ServiceName: "v3lockpb.Lock",
+	HandlerType: (*LockServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "Lock",
+			Handler:    _Lock_Lock_Handler,
+		},
+		{
+			MethodName: "Unlock",
+			Handler:    _Lock_Unlock_Handler,
+		},
+	},
+	Streams:  []grpc.StreamDesc{},
+	Metadata: "v3lock.proto",
+}
+
+func (m *LockRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LockRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Name) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(len(m.Name)))
+		i += copy(dAtA[i:], m.Name)
+	}
+	if m.Lease != 0 {
+		dAtA[i] = 0x10
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(m.Lease))
+	}
+	return i, nil
+}
+
+func (m *LockResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LockResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(m.Header.Size()))
+		n1, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n1
+	}
+	if len(m.Key) > 0 {
+		dAtA[i] = 0x12
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(len(m.Key)))
+		i += copy(dAtA[i:], m.Key)
+	}
+	return i, nil
+}
+
+func (m *UnlockRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *UnlockRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if len(m.Key) > 0 {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(len(m.Key)))
+		i += copy(dAtA[i:], m.Key)
+	}
+	return i, nil
+}
+
+func (m *UnlockResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *UnlockResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.Header != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintV3Lock(dAtA, i, uint64(m.Header.Size()))
+		n2, err := m.Header.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n2
+	}
+	return i, nil
+}
+
+func encodeVarintV3Lock(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *LockRequest) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Name)
+	if l > 0 {
+		n += 1 + l + sovV3Lock(uint64(l))
+	}
+	if m.Lease != 0 {
+		n += 1 + sovV3Lock(uint64(m.Lease))
+	}
+	return n
+}
+
+func (m *LockResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Lock(uint64(l))
+	}
+	l = len(m.Key)
+	if l > 0 {
+		n += 1 + l + sovV3Lock(uint64(l))
+	}
+	return n
+}
+
+func (m *UnlockRequest) Size() (n int) {
+	var l int
+	_ = l
+	l = len(m.Key)
+	if l > 0 {
+		n += 1 + l + sovV3Lock(uint64(l))
+	}
+	return n
+}
+
+func (m *UnlockResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.Header != nil {
+		l = m.Header.Size()
+		n += 1 + l + sovV3Lock(uint64(l))
+	}
+	return n
+}
+
+func sovV3Lock(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozV3Lock(x uint64) (n int) {
+	return sovV3Lock(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *LockRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Lock
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LockRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LockRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Name", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Name = append(m.Name[:0], dAtA[iNdEx:postIndex]...)
+			if m.Name == nil {
+				m.Name = []byte{}
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Lease", wireType)
+			}
+			m.Lease = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Lease |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Lock(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LockResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Lock
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LockResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LockResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Key", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Key = append(m.Key[:0], dAtA[iNdEx:postIndex]...)
+			if m.Key == nil {
+				m.Key = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Lock(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *UnlockRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Lock
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: UnlockRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: UnlockRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Key", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Key = append(m.Key[:0], dAtA[iNdEx:postIndex]...)
+			if m.Key == nil {
+				m.Key = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Lock(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *UnlockResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowV3Lock
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: UnlockResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: UnlockResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Header", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.Header == nil {
+				m.Header = &etcdserverpb.ResponseHeader{}
+			}
+			if err := m.Header.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipV3Lock(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthV3Lock
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipV3Lock(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowV3Lock
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowV3Lock
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthV3Lock
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowV3Lock
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipV3Lock(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthV3Lock = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowV3Lock   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("v3lock.proto", fileDescriptorV3Lock) }
+
+var fileDescriptorV3Lock = []byte{
+	// 331 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x29, 0x33, 0xce, 0xc9,
+	0x4f, 0xce, 0xd6, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0xe2, 0x80, 0xf0, 0x0a, 0x92, 0xa4, 0x44,
+	0xd2, 0xf3, 0xd3, 0xf3, 0xc1, 0x82, 0xfa, 0x20, 0x16, 0x44, 0x5e, 0x4a, 0x2d, 0xb5, 0x24, 0x39,
+	0x45, 0x1f, 0x44, 0x14, 0xa7, 0x16, 0x95, 0xa5, 0x16, 0x21, 0x31, 0x0b, 0x92, 0xf4, 0x8b, 0x0a,
+	0x92, 0xa1, 0xea, 0x64, 0xd2, 0xf3, 0xf3, 0xd3, 0x73, 0x52, 0xf5, 0x13, 0x0b, 0x32, 0xf5, 0x13,
+	0xf3, 0xf2, 0xf2, 0x4b, 0x12, 0x4b, 0x32, 0xf3, 0xf3, 0x8a, 0x21, 0xb2, 0x4a, 0xe6, 0x5c, 0xdc,
+	0x3e, 0xf9, 0xc9, 0xd9, 0x41, 0xa9, 0x85, 0xa5, 0xa9, 0xc5, 0x25, 0x42, 0x42, 0x5c, 0x2c, 0x79,
+	0x89, 0xb9, 0xa9, 0x12, 0x8c, 0x0a, 0x8c, 0x1a, 0x3c, 0x41, 0x60, 0xb6, 0x90, 0x08, 0x17, 0x6b,
+	0x4e, 0x6a, 0x62, 0x71, 0xaa, 0x04, 0x93, 0x02, 0xa3, 0x06, 0x73, 0x10, 0x84, 0xa3, 0x14, 0xc6,
+	0xc5, 0x03, 0xd1, 0x58, 0x5c, 0x90, 0x9f, 0x57, 0x9c, 0x2a, 0x64, 0xc2, 0xc5, 0x96, 0x91, 0x9a,
+	0x98, 0x92, 0x5a, 0x04, 0xd6, 0xcb, 0x6d, 0x24, 0xa3, 0x87, 0xec, 0x1e, 0x3d, 0x98, 0x3a, 0x0f,
+	0xb0, 0x9a, 0x20, 0xa8, 0x5a, 0x21, 0x01, 0x2e, 0xe6, 0xec, 0xd4, 0x4a, 0xb0, 0xc9, 0x3c, 0x41,
+	0x20, 0xa6, 0x92, 0x22, 0x17, 0x6f, 0x68, 0x5e, 0x0e, 0x92, 0x93, 0xa0, 0x4a, 0x18, 0x11, 0x4a,
+	0xdc, 0xb8, 0xf8, 0x60, 0x4a, 0x28, 0xb1, 0xdc, 0x68, 0x03, 0x23, 0x17, 0x0b, 0xc8, 0x0f, 0x42,
+	0xfe, 0x50, 0x5a, 0x54, 0x0f, 0x16, 0xe6, 0x7a, 0x48, 0x81, 0x22, 0x25, 0x86, 0x2e, 0x0c, 0x31,
+	0x4d, 0x49, 0xa2, 0xe9, 0xf2, 0x93, 0xc9, 0x4c, 0x42, 0x4a, 0xbc, 0xfa, 0x65, 0xc6, 0xfa, 0x20,
+	0x05, 0x60, 0xc2, 0x8a, 0x51, 0x4b, 0x28, 0x9c, 0x8b, 0x0d, 0xe2, 0x42, 0x21, 0x71, 0x84, 0x5e,
+	0x14, 0x6f, 0x49, 0x49, 0x60, 0x4a, 0x40, 0x8d, 0x95, 0x02, 0x1b, 0x2b, 0xa2, 0xc4, 0x0f, 0x37,
+	0xb6, 0x34, 0x0f, 0x6a, 0xb0, 0x93, 0xc0, 0x89, 0x47, 0x72, 0x8c, 0x17, 0x1e, 0xc9, 0x31, 0x3e,
+	0x78, 0x24, 0xc7, 0x38, 0xe3, 0xb1, 0x1c, 0x43, 0x12, 0x1b, 0x38, 0x1e, 0x8d, 0x01, 0x01, 0x00,
+	0x00, 0xff, 0xff, 0x65, 0xa8, 0x61, 0xb1, 0x3d, 0x02, 0x00, 0x00,
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.proto b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.proto
new file mode 100644
index 0000000..7220c7f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb/v3lock.proto
@@ -0,0 +1,65 @@
+syntax = "proto3";
+package v3lockpb;
+
+import "gogoproto/gogo.proto";
+import "etcd/etcdserver/etcdserverpb/rpc.proto";
+
+// for grpc-gateway
+import "google/api/annotations.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+
+// The lock service exposes client-side locking facilities as a gRPC interface.
+service Lock {
+  // Lock acquires a distributed shared lock on a given named lock.
+  // On success, it will return a unique key that exists so long as the
+  // lock is held by the caller. This key can be used in conjunction with
+  // transactions to safely ensure updates to etcd only occur while holding
+  // lock ownership. The lock is held until Unlock is called on the key or the
+  // lease associate with the owner expires.
+  rpc Lock(LockRequest) returns (LockResponse) {
+      option (google.api.http) = {
+        post: "/v3/lock/lock"
+        body: "*"
+    };
+  }
+
+  // Unlock takes a key returned by Lock and releases the hold on lock. The
+  // next Lock caller waiting for the lock will then be woken up and given
+  // ownership of the lock.
+  rpc Unlock(UnlockRequest) returns (UnlockResponse) {
+      option (google.api.http) = {
+        post: "/v3/lock/unlock"
+        body: "*"
+    };
+  }
+}
+
+message LockRequest {
+  // name is the identifier for the distributed shared lock to be acquired.
+  bytes name = 1;
+  // lease is the ID of the lease that will be attached to ownership of the
+  // lock. If the lease expires or is revoked and currently holds the lock,
+  // the lock is automatically released. Calls to Lock with the same lease will
+  // be treated as a single acquisition; locking twice with the same lease is a
+  // no-op.
+  int64 lease = 2;
+}
+
+message LockResponse {
+  etcdserverpb.ResponseHeader header = 1;
+  // key is a key that will exist on etcd for the duration that the Lock caller
+  // owns the lock. Users should not modify this key or the lock may exhibit
+  // undefined behavior.
+  bytes key = 2;
+}
+
+message UnlockRequest {
+  // key is the lock ownership key granted by Lock.
+  bytes key = 1;
+}
+
+message UnlockResponse {
+  etcdserverpb.ResponseHeader header = 1;
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/auth.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/auth.go
new file mode 100644
index 0000000..62ce757
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/auth.go
@@ -0,0 +1,158 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/etcdserver"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+)
+
+type AuthServer struct {
+	authenticator etcdserver.Authenticator
+}
+
+func NewAuthServer(s *etcdserver.EtcdServer) *AuthServer {
+	return &AuthServer{authenticator: s}
+}
+
+func (as *AuthServer) AuthEnable(ctx context.Context, r *pb.AuthEnableRequest) (*pb.AuthEnableResponse, error) {
+	resp, err := as.authenticator.AuthEnable(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) AuthDisable(ctx context.Context, r *pb.AuthDisableRequest) (*pb.AuthDisableResponse, error) {
+	resp, err := as.authenticator.AuthDisable(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) Authenticate(ctx context.Context, r *pb.AuthenticateRequest) (*pb.AuthenticateResponse, error) {
+	resp, err := as.authenticator.Authenticate(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleAdd(ctx context.Context, r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error) {
+	resp, err := as.authenticator.RoleAdd(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleDelete(ctx context.Context, r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	resp, err := as.authenticator.RoleDelete(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleGet(ctx context.Context, r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	resp, err := as.authenticator.RoleGet(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleList(ctx context.Context, r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error) {
+	resp, err := as.authenticator.RoleList(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleRevokePermission(ctx context.Context, r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error) {
+	resp, err := as.authenticator.RoleRevokePermission(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) RoleGrantPermission(ctx context.Context, r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error) {
+	resp, err := as.authenticator.RoleGrantPermission(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserAdd(ctx context.Context, r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error) {
+	resp, err := as.authenticator.UserAdd(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserDelete(ctx context.Context, r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	resp, err := as.authenticator.UserDelete(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserGet(ctx context.Context, r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	resp, err := as.authenticator.UserGet(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserList(ctx context.Context, r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error) {
+	resp, err := as.authenticator.UserList(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserGrantRole(ctx context.Context, r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error) {
+	resp, err := as.authenticator.UserGrantRole(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserRevokeRole(ctx context.Context, r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	resp, err := as.authenticator.UserRevokeRole(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
+
+func (as *AuthServer) UserChangePassword(ctx context.Context, r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error) {
+	resp, err := as.authenticator.UserChangePassword(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return resp, nil
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/codec.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/codec.go
new file mode 100644
index 0000000..17a2c87
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/codec.go
@@ -0,0 +1,34 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import "github.com/gogo/protobuf/proto"
+
+type codec struct{}
+
+func (c *codec) Marshal(v interface{}) ([]byte, error) {
+	b, err := proto.Marshal(v.(proto.Message))
+	sentBytes.Add(float64(len(b)))
+	return b, err
+}
+
+func (c *codec) Unmarshal(data []byte, v interface{}) error {
+	receivedBytes.Add(float64(len(data)))
+	return proto.Unmarshal(data, v.(proto.Message))
+}
+
+func (c *codec) String() string {
+	return "proto"
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/grpc.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/grpc.go
new file mode 100644
index 0000000..3332016
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/grpc.go
@@ -0,0 +1,77 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"crypto/tls"
+	"math"
+
+	"go.etcd.io/etcd/etcdserver"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
+	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
+	"go.etcd.io/etcd/clientv3/credentials"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/health"
+	healthpb "google.golang.org/grpc/health/grpc_health_v1"
+)
+
+const (
+	grpcOverheadBytes = 512 * 1024
+	maxStreams        = math.MaxUint32
+	maxSendBytes      = math.MaxInt32
+)
+
+func Server(s *etcdserver.EtcdServer, tls *tls.Config, gopts ...grpc.ServerOption) *grpc.Server {
+	var opts []grpc.ServerOption
+	opts = append(opts, grpc.CustomCodec(&codec{}))
+	if tls != nil {
+		bundle := credentials.NewBundle(credentials.Config{TLSConfig: tls})
+		opts = append(opts, grpc.Creds(bundle.TransportCredentials()))
+	}
+	opts = append(opts, grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
+		newLogUnaryInterceptor(s),
+		newUnaryInterceptor(s),
+		grpc_prometheus.UnaryServerInterceptor,
+	)))
+	opts = append(opts, grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
+		newStreamInterceptor(s),
+		grpc_prometheus.StreamServerInterceptor,
+	)))
+	opts = append(opts, grpc.MaxRecvMsgSize(int(s.Cfg.MaxRequestBytes+grpcOverheadBytes)))
+	opts = append(opts, grpc.MaxSendMsgSize(maxSendBytes))
+	opts = append(opts, grpc.MaxConcurrentStreams(maxStreams))
+	grpcServer := grpc.NewServer(append(opts, gopts...)...)
+
+	pb.RegisterKVServer(grpcServer, NewQuotaKVServer(s))
+	pb.RegisterWatchServer(grpcServer, NewWatchServer(s))
+	pb.RegisterLeaseServer(grpcServer, NewQuotaLeaseServer(s))
+	pb.RegisterClusterServer(grpcServer, NewClusterServer(s))
+	pb.RegisterAuthServer(grpcServer, NewAuthServer(s))
+	pb.RegisterMaintenanceServer(grpcServer, NewMaintenanceServer(s))
+
+	// server should register all the services manually
+	// use empty service name for all etcd services' health status,
+	// see https://github.com/grpc/grpc/blob/master/doc/health-checking.md for more
+	hsrv := health.NewServer()
+	hsrv.SetServingStatus("", healthpb.HealthCheckResponse_SERVING)
+	healthpb.RegisterHealthServer(grpcServer, hsrv)
+
+	// set zero values for metrics registered for this grpc server
+	grpc_prometheus.Register(grpcServer)
+
+	return grpcServer
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/header.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/header.go
new file mode 100644
index 0000000..f23b6a7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/header.go
@@ -0,0 +1,49 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"go.etcd.io/etcd/etcdserver"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+)
+
+type header struct {
+	clusterID int64
+	memberID  int64
+	sg        etcdserver.RaftStatusGetter
+	rev       func() int64
+}
+
+func newHeader(s *etcdserver.EtcdServer) header {
+	return header{
+		clusterID: int64(s.Cluster().ID()),
+		memberID:  int64(s.ID()),
+		sg:        s,
+		rev:       func() int64 { return s.KV().Rev() },
+	}
+}
+
+// fill populates pb.ResponseHeader using etcdserver information
+func (h *header) fill(rh *pb.ResponseHeader) {
+	if rh == nil {
+		plog.Panic("unexpected nil resp.Header")
+	}
+	rh.ClusterId = uint64(h.clusterID)
+	rh.MemberId = uint64(h.memberID)
+	rh.RaftTerm = h.sg.Term()
+	if rh.Revision == 0 {
+		rh.Revision = h.rev()
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/interceptor.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/interceptor.go
new file mode 100644
index 0000000..ce9047e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/interceptor.go
@@ -0,0 +1,276 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+
+	"github.com/coreos/pkg/capnslog"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/peer"
+)
+
+const (
+	maxNoLeaderCnt = 3
+)
+
+type streamsMap struct {
+	mu      sync.Mutex
+	streams map[grpc.ServerStream]struct{}
+}
+
+func newUnaryInterceptor(s *etcdserver.EtcdServer) grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		if !api.IsCapabilityEnabled(api.V3rpcCapability) {
+			return nil, rpctypes.ErrGRPCNotCapable
+		}
+
+		if s.IsMemberExist(s.ID()) && s.IsLearner() && !isRPCSupportedForLearner(req) {
+			return nil, rpctypes.ErrGPRCNotSupportedForLearner
+		}
+
+		md, ok := metadata.FromIncomingContext(ctx)
+		if ok {
+			if ks := md[rpctypes.MetadataRequireLeaderKey]; len(ks) > 0 && ks[0] == rpctypes.MetadataHasLeader {
+				if s.Leader() == types.ID(raft.None) {
+					return nil, rpctypes.ErrGRPCNoLeader
+				}
+			}
+		}
+
+		return handler(ctx, req)
+	}
+}
+
+func newLogUnaryInterceptor(s *etcdserver.EtcdServer) grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		startTime := time.Now()
+		resp, err := handler(ctx, req)
+		lg := s.Logger()
+		if (lg != nil && lg.Core().Enabled(zap.DebugLevel)) || // using zap logger and debug level is enabled
+			(lg == nil && plog.LevelAt(capnslog.DEBUG)) { // or, using capnslog and debug level is enabled
+			defer logUnaryRequestStats(ctx, lg, info, startTime, req, resp)
+		}
+		return resp, err
+	}
+}
+
+func logUnaryRequestStats(ctx context.Context, lg *zap.Logger, info *grpc.UnaryServerInfo, startTime time.Time, req interface{}, resp interface{}) {
+	duration := time.Since(startTime)
+	remote := "No remote client info."
+	peerInfo, ok := peer.FromContext(ctx)
+	if ok {
+		remote = peerInfo.Addr.String()
+	}
+	responseType := info.FullMethod
+	var reqCount, respCount int64
+	var reqSize, respSize int
+	var reqContent string
+	switch _resp := resp.(type) {
+	case *pb.RangeResponse:
+		_req, ok := req.(*pb.RangeRequest)
+		if ok {
+			reqCount = 0
+			reqSize = _req.Size()
+			reqContent = _req.String()
+		}
+		if _resp != nil {
+			respCount = _resp.GetCount()
+			respSize = _resp.Size()
+		}
+	case *pb.PutResponse:
+		_req, ok := req.(*pb.PutRequest)
+		if ok {
+			reqCount = 1
+			reqSize = _req.Size()
+			reqContent = pb.NewLoggablePutRequest(_req).String()
+			// redact value field from request content, see PR #9821
+		}
+		if _resp != nil {
+			respCount = 0
+			respSize = _resp.Size()
+		}
+	case *pb.DeleteRangeResponse:
+		_req, ok := req.(*pb.DeleteRangeRequest)
+		if ok {
+			reqCount = 0
+			reqSize = _req.Size()
+			reqContent = _req.String()
+		}
+		if _resp != nil {
+			respCount = _resp.GetDeleted()
+			respSize = _resp.Size()
+		}
+	case *pb.TxnResponse:
+		_req, ok := req.(*pb.TxnRequest)
+		if ok && _resp != nil {
+			if _resp.GetSucceeded() { // determine the 'actual' count and size of request based on success or failure
+				reqCount = int64(len(_req.GetSuccess()))
+				reqSize = 0
+				for _, r := range _req.GetSuccess() {
+					reqSize += r.Size()
+				}
+			} else {
+				reqCount = int64(len(_req.GetFailure()))
+				reqSize = 0
+				for _, r := range _req.GetFailure() {
+					reqSize += r.Size()
+				}
+			}
+			reqContent = pb.NewLoggableTxnRequest(_req).String()
+			// redact value field from request content, see PR #9821
+		}
+		if _resp != nil {
+			respCount = 0
+			respSize = _resp.Size()
+		}
+	default:
+		reqCount = -1
+		reqSize = -1
+		respCount = -1
+		respSize = -1
+	}
+
+	logGenericRequestStats(lg, startTime, duration, remote, responseType, reqCount, reqSize, respCount, respSize, reqContent)
+}
+
+func logGenericRequestStats(lg *zap.Logger, startTime time.Time, duration time.Duration, remote string, responseType string,
+	reqCount int64, reqSize int, respCount int64, respSize int, reqContent string) {
+	if lg == nil {
+		plog.Debugf("start time = %v, "+
+			"time spent = %v, "+
+			"remote = %s, "+
+			"response type = %s, "+
+			"request count = %d, "+
+			"request size = %d, "+
+			"response count = %d, "+
+			"response size = %d, "+
+			"request content = %s",
+			startTime, duration, remote, responseType, reqCount, reqSize, respCount, respSize, reqContent,
+		)
+	} else {
+		lg.Debug("request stats",
+			zap.Time("start time", startTime),
+			zap.Duration("time spent", duration),
+			zap.String("remote", remote),
+			zap.String("response type", responseType),
+			zap.Int64("request count", reqCount),
+			zap.Int("request size", reqSize),
+			zap.Int64("response count", respCount),
+			zap.Int("response size", respSize),
+			zap.String("request content", reqContent),
+		)
+	}
+}
+
+func newStreamInterceptor(s *etcdserver.EtcdServer) grpc.StreamServerInterceptor {
+	smap := monitorLeader(s)
+
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if !api.IsCapabilityEnabled(api.V3rpcCapability) {
+			return rpctypes.ErrGRPCNotCapable
+		}
+
+		if s.IsMemberExist(s.ID()) && s.IsLearner() { // learner does not support stream RPC
+			return rpctypes.ErrGPRCNotSupportedForLearner
+		}
+
+		md, ok := metadata.FromIncomingContext(ss.Context())
+		if ok {
+			if ks := md[rpctypes.MetadataRequireLeaderKey]; len(ks) > 0 && ks[0] == rpctypes.MetadataHasLeader {
+				if s.Leader() == types.ID(raft.None) {
+					return rpctypes.ErrGRPCNoLeader
+				}
+
+				cctx, cancel := context.WithCancel(ss.Context())
+				ss = serverStreamWithCtx{ctx: cctx, cancel: &cancel, ServerStream: ss}
+
+				smap.mu.Lock()
+				smap.streams[ss] = struct{}{}
+				smap.mu.Unlock()
+
+				defer func() {
+					smap.mu.Lock()
+					delete(smap.streams, ss)
+					smap.mu.Unlock()
+					cancel()
+				}()
+
+			}
+		}
+
+		return handler(srv, ss)
+	}
+}
+
+type serverStreamWithCtx struct {
+	grpc.ServerStream
+	ctx    context.Context
+	cancel *context.CancelFunc
+}
+
+func (ssc serverStreamWithCtx) Context() context.Context { return ssc.ctx }
+
+func monitorLeader(s *etcdserver.EtcdServer) *streamsMap {
+	smap := &streamsMap{
+		streams: make(map[grpc.ServerStream]struct{}),
+	}
+
+	go func() {
+		election := time.Duration(s.Cfg.TickMs) * time.Duration(s.Cfg.ElectionTicks) * time.Millisecond
+		noLeaderCnt := 0
+
+		for {
+			select {
+			case <-s.StopNotify():
+				return
+			case <-time.After(election):
+				if s.Leader() == types.ID(raft.None) {
+					noLeaderCnt++
+				} else {
+					noLeaderCnt = 0
+				}
+
+				// We are more conservative on canceling existing streams. Reconnecting streams
+				// cost much more than just rejecting new requests. So we wait until the member
+				// cannot find a leader for maxNoLeaderCnt election timeouts to cancel existing streams.
+				if noLeaderCnt >= maxNoLeaderCnt {
+					smap.mu.Lock()
+					for ss := range smap.streams {
+						if ssWithCtx, ok := ss.(serverStreamWithCtx); ok {
+							(*ssWithCtx.cancel)()
+							<-ss.Context().Done()
+						}
+					}
+					smap.streams = make(map[grpc.ServerStream]struct{})
+					smap.mu.Unlock()
+				}
+			}
+		}
+	}()
+
+	return smap
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/key.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/key.go
new file mode 100644
index 0000000..ff59bac
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/key.go
@@ -0,0 +1,277 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package v3rpc implements etcd v3 RPC system based on gRPC.
+package v3rpc
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/adt"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api/v3rpc")
+)
+
+type kvServer struct {
+	hdr header
+	kv  etcdserver.RaftKV
+	// maxTxnOps is the max operations per txn.
+	// e.g suppose maxTxnOps = 128.
+	// Txn.Success can have at most 128 operations,
+	// and Txn.Failure can have at most 128 operations.
+	maxTxnOps uint
+}
+
+func NewKVServer(s *etcdserver.EtcdServer) pb.KVServer {
+	return &kvServer{hdr: newHeader(s), kv: s, maxTxnOps: s.Cfg.MaxTxnOps}
+}
+
+func (s *kvServer) Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	if err := checkRangeRequest(r); err != nil {
+		return nil, err
+	}
+
+	resp, err := s.kv.Range(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	s.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (s *kvServer) Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error) {
+	if err := checkPutRequest(r); err != nil {
+		return nil, err
+	}
+
+	resp, err := s.kv.Put(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	s.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (s *kvServer) DeleteRange(ctx context.Context, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	if err := checkDeleteRequest(r); err != nil {
+		return nil, err
+	}
+
+	resp, err := s.kv.DeleteRange(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	s.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (s *kvServer) Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if err := checkTxnRequest(r, int(s.maxTxnOps)); err != nil {
+		return nil, err
+	}
+	// check for forbidden put/del overlaps after checking request to avoid quadratic blowup
+	if _, _, err := checkIntervals(r.Success); err != nil {
+		return nil, err
+	}
+	if _, _, err := checkIntervals(r.Failure); err != nil {
+		return nil, err
+	}
+
+	resp, err := s.kv.Txn(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	s.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (s *kvServer) Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error) {
+	resp, err := s.kv.Compact(ctx, r)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	s.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func checkRangeRequest(r *pb.RangeRequest) error {
+	if len(r.Key) == 0 {
+		return rpctypes.ErrGRPCEmptyKey
+	}
+	return nil
+}
+
+func checkPutRequest(r *pb.PutRequest) error {
+	if len(r.Key) == 0 {
+		return rpctypes.ErrGRPCEmptyKey
+	}
+	if r.IgnoreValue && len(r.Value) != 0 {
+		return rpctypes.ErrGRPCValueProvided
+	}
+	if r.IgnoreLease && r.Lease != 0 {
+		return rpctypes.ErrGRPCLeaseProvided
+	}
+	return nil
+}
+
+func checkDeleteRequest(r *pb.DeleteRangeRequest) error {
+	if len(r.Key) == 0 {
+		return rpctypes.ErrGRPCEmptyKey
+	}
+	return nil
+}
+
+func checkTxnRequest(r *pb.TxnRequest, maxTxnOps int) error {
+	opc := len(r.Compare)
+	if opc < len(r.Success) {
+		opc = len(r.Success)
+	}
+	if opc < len(r.Failure) {
+		opc = len(r.Failure)
+	}
+	if opc > maxTxnOps {
+		return rpctypes.ErrGRPCTooManyOps
+	}
+
+	for _, c := range r.Compare {
+		if len(c.Key) == 0 {
+			return rpctypes.ErrGRPCEmptyKey
+		}
+	}
+	for _, u := range r.Success {
+		if err := checkRequestOp(u, maxTxnOps-opc); err != nil {
+			return err
+		}
+	}
+	for _, u := range r.Failure {
+		if err := checkRequestOp(u, maxTxnOps-opc); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// checkIntervals tests whether puts and deletes overlap for a list of ops. If
+// there is an overlap, returns an error. If no overlap, return put and delete
+// sets for recursive evaluation.
+func checkIntervals(reqs []*pb.RequestOp) (map[string]struct{}, adt.IntervalTree, error) {
+	dels := adt.NewIntervalTree()
+
+	// collect deletes from this level; build first to check lower level overlapped puts
+	for _, req := range reqs {
+		tv, ok := req.Request.(*pb.RequestOp_RequestDeleteRange)
+		if !ok {
+			continue
+		}
+		dreq := tv.RequestDeleteRange
+		if dreq == nil {
+			continue
+		}
+		var iv adt.Interval
+		if len(dreq.RangeEnd) != 0 {
+			iv = adt.NewStringAffineInterval(string(dreq.Key), string(dreq.RangeEnd))
+		} else {
+			iv = adt.NewStringAffinePoint(string(dreq.Key))
+		}
+		dels.Insert(iv, struct{}{})
+	}
+
+	// collect children puts/deletes
+	puts := make(map[string]struct{})
+	for _, req := range reqs {
+		tv, ok := req.Request.(*pb.RequestOp_RequestTxn)
+		if !ok {
+			continue
+		}
+		putsThen, delsThen, err := checkIntervals(tv.RequestTxn.Success)
+		if err != nil {
+			return nil, dels, err
+		}
+		putsElse, delsElse, err := checkIntervals(tv.RequestTxn.Failure)
+		if err != nil {
+			return nil, dels, err
+		}
+		for k := range putsThen {
+			if _, ok := puts[k]; ok {
+				return nil, dels, rpctypes.ErrGRPCDuplicateKey
+			}
+			if dels.Intersects(adt.NewStringAffinePoint(k)) {
+				return nil, dels, rpctypes.ErrGRPCDuplicateKey
+			}
+			puts[k] = struct{}{}
+		}
+		for k := range putsElse {
+			if _, ok := puts[k]; ok {
+				// if key is from putsThen, overlap is OK since
+				// either then/else are mutually exclusive
+				if _, isSafe := putsThen[k]; !isSafe {
+					return nil, dels, rpctypes.ErrGRPCDuplicateKey
+				}
+			}
+			if dels.Intersects(adt.NewStringAffinePoint(k)) {
+				return nil, dels, rpctypes.ErrGRPCDuplicateKey
+			}
+			puts[k] = struct{}{}
+		}
+		dels.Union(delsThen, adt.NewStringAffineInterval("\x00", ""))
+		dels.Union(delsElse, adt.NewStringAffineInterval("\x00", ""))
+	}
+
+	// collect and check this level's puts
+	for _, req := range reqs {
+		tv, ok := req.Request.(*pb.RequestOp_RequestPut)
+		if !ok || tv.RequestPut == nil {
+			continue
+		}
+		k := string(tv.RequestPut.Key)
+		if _, ok := puts[k]; ok {
+			return nil, dels, rpctypes.ErrGRPCDuplicateKey
+		}
+		if dels.Intersects(adt.NewStringAffinePoint(k)) {
+			return nil, dels, rpctypes.ErrGRPCDuplicateKey
+		}
+		puts[k] = struct{}{}
+	}
+	return puts, dels, nil
+}
+
+func checkRequestOp(u *pb.RequestOp, maxTxnOps int) error {
+	// TODO: ensure only one of the field is set.
+	switch uv := u.Request.(type) {
+	case *pb.RequestOp_RequestRange:
+		return checkRangeRequest(uv.RequestRange)
+	case *pb.RequestOp_RequestPut:
+		return checkPutRequest(uv.RequestPut)
+	case *pb.RequestOp_RequestDeleteRange:
+		return checkDeleteRequest(uv.RequestDeleteRange)
+	case *pb.RequestOp_RequestTxn:
+		return checkTxnRequest(uv.RequestTxn, maxTxnOps)
+	default:
+		// empty op / nil entry
+		return rpctypes.ErrGRPCKeyNotFound
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go
new file mode 100644
index 0000000..7441bee
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/lease.go
@@ -0,0 +1,169 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"io"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+
+	"go.uber.org/zap"
+)
+
+type LeaseServer struct {
+	lg  *zap.Logger
+	hdr header
+	le  etcdserver.Lessor
+}
+
+func NewLeaseServer(s *etcdserver.EtcdServer) pb.LeaseServer {
+	return &LeaseServer{lg: s.Cfg.Logger, le: s, hdr: newHeader(s)}
+}
+
+func (ls *LeaseServer) LeaseGrant(ctx context.Context, cr *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	resp, err := ls.le.LeaseGrant(ctx, cr)
+
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseRevoke(ctx context.Context, rr *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	resp, err := ls.le.LeaseRevoke(ctx, rr)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseTimeToLive(ctx context.Context, rr *pb.LeaseTimeToLiveRequest) (*pb.LeaseTimeToLiveResponse, error) {
+	resp, err := ls.le.LeaseTimeToLive(ctx, rr)
+	if err != nil && err != lease.ErrLeaseNotFound {
+		return nil, togRPCError(err)
+	}
+	if err == lease.ErrLeaseNotFound {
+		resp = &pb.LeaseTimeToLiveResponse{
+			Header: &pb.ResponseHeader{},
+			ID:     rr.ID,
+			TTL:    -1,
+		}
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseLeases(ctx context.Context, rr *pb.LeaseLeasesRequest) (*pb.LeaseLeasesResponse, error) {
+	resp, err := ls.le.LeaseLeases(ctx, rr)
+	if err != nil && err != lease.ErrLeaseNotFound {
+		return nil, togRPCError(err)
+	}
+	if err == lease.ErrLeaseNotFound {
+		resp = &pb.LeaseLeasesResponse{
+			Header: &pb.ResponseHeader{},
+			Leases: []*pb.LeaseStatus{},
+		}
+	}
+	ls.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ls *LeaseServer) LeaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) (err error) {
+	errc := make(chan error, 1)
+	go func() {
+		errc <- ls.leaseKeepAlive(stream)
+	}()
+	select {
+	case err = <-errc:
+	case <-stream.Context().Done():
+		// the only server-side cancellation is noleader for now.
+		err = stream.Context().Err()
+		if err == context.Canceled {
+			err = rpctypes.ErrGRPCNoLeader
+		}
+	}
+	return err
+}
+
+func (ls *LeaseServer) leaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) error {
+	for {
+		req, err := stream.Recv()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			if isClientCtxErr(stream.Context().Err(), err) {
+				if ls.lg != nil {
+					ls.lg.Debug("failed to receive lease keepalive request from gRPC stream", zap.Error(err))
+				} else {
+					plog.Debugf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+				}
+			} else {
+				if ls.lg != nil {
+					ls.lg.Warn("failed to receive lease keepalive request from gRPC stream", zap.Error(err))
+				} else {
+					plog.Warningf("failed to receive lease keepalive request from gRPC stream (%q)", err.Error())
+				}
+				streamFailures.WithLabelValues("receive", "lease-keepalive").Inc()
+			}
+			return err
+		}
+
+		// Create header before we sent out the renew request.
+		// This can make sure that the revision is strictly smaller or equal to
+		// when the keepalive happened at the local server (when the local server is the leader)
+		// or remote leader.
+		// Without this, a lease might be revoked at rev 3 but client can see the keepalive succeeded
+		// at rev 4.
+		resp := &pb.LeaseKeepAliveResponse{ID: req.ID, Header: &pb.ResponseHeader{}}
+		ls.hdr.fill(resp.Header)
+
+		ttl, err := ls.le.LeaseRenew(stream.Context(), lease.LeaseID(req.ID))
+		if err == lease.ErrLeaseNotFound {
+			err = nil
+			ttl = 0
+		}
+
+		if err != nil {
+			return togRPCError(err)
+		}
+
+		resp.TTL = ttl
+		err = stream.Send(resp)
+		if err != nil {
+			if isClientCtxErr(stream.Context().Err(), err) {
+				if ls.lg != nil {
+					ls.lg.Debug("failed to send lease keepalive response to gRPC stream", zap.Error(err))
+				} else {
+					plog.Debugf("failed to send lease keepalive response to gRPC stream (%q)", err.Error())
+				}
+			} else {
+				if ls.lg != nil {
+					ls.lg.Warn("failed to send lease keepalive response to gRPC stream", zap.Error(err))
+				} else {
+					plog.Warningf("failed to send lease keepalive response to gRPC stream (%q)", err.Error())
+				}
+				streamFailures.WithLabelValues("send", "lease-keepalive").Inc()
+			}
+			return err
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/maintenance.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/maintenance.go
new file mode 100644
index 0000000..c51271a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/maintenance.go
@@ -0,0 +1,260 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"crypto/sha256"
+	"io"
+
+	"go.etcd.io/etcd/auth"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/version"
+
+	"go.uber.org/zap"
+)
+
+type KVGetter interface {
+	KV() mvcc.ConsistentWatchableKV
+}
+
+type BackendGetter interface {
+	Backend() backend.Backend
+}
+
+type Alarmer interface {
+	// Alarms is implemented in Server interface located in etcdserver/server.go
+	// It returns a list of alarms present in the AlarmStore
+	Alarms() []*pb.AlarmMember
+	Alarm(ctx context.Context, ar *pb.AlarmRequest) (*pb.AlarmResponse, error)
+}
+
+type LeaderTransferrer interface {
+	MoveLeader(ctx context.Context, lead, target uint64) error
+}
+
+type AuthGetter interface {
+	AuthInfoFromCtx(ctx context.Context) (*auth.AuthInfo, error)
+	AuthStore() auth.AuthStore
+}
+
+type ClusterStatusGetter interface {
+	IsLearner() bool
+}
+
+type maintenanceServer struct {
+	lg  *zap.Logger
+	rg  etcdserver.RaftStatusGetter
+	kg  KVGetter
+	bg  BackendGetter
+	a   Alarmer
+	lt  LeaderTransferrer
+	hdr header
+	cs  ClusterStatusGetter
+}
+
+func NewMaintenanceServer(s *etcdserver.EtcdServer) pb.MaintenanceServer {
+	srv := &maintenanceServer{lg: s.Cfg.Logger, rg: s, kg: s, bg: s, a: s, lt: s, hdr: newHeader(s), cs: s}
+	return &authMaintenanceServer{srv, s}
+}
+
+func (ms *maintenanceServer) Defragment(ctx context.Context, sr *pb.DefragmentRequest) (*pb.DefragmentResponse, error) {
+	if ms.lg != nil {
+		ms.lg.Info("starting defragment")
+	} else {
+		plog.Noticef("starting to defragment the storage backend...")
+	}
+	err := ms.bg.Backend().Defrag()
+	if err != nil {
+		if ms.lg != nil {
+			ms.lg.Warn("failed to defragment", zap.Error(err))
+		} else {
+			plog.Errorf("failed to defragment the storage backend (%v)", err)
+		}
+		return nil, err
+	}
+	if ms.lg != nil {
+		ms.lg.Info("finished defragment")
+	} else {
+		plog.Noticef("finished defragmenting the storage backend")
+	}
+	return &pb.DefragmentResponse{}, nil
+}
+
+func (ms *maintenanceServer) Snapshot(sr *pb.SnapshotRequest, srv pb.Maintenance_SnapshotServer) error {
+	snap := ms.bg.Backend().Snapshot()
+	pr, pw := io.Pipe()
+
+	defer pr.Close()
+
+	go func() {
+		snap.WriteTo(pw)
+		if err := snap.Close(); err != nil {
+			if ms.lg != nil {
+				ms.lg.Warn("failed to close snapshot", zap.Error(err))
+			} else {
+				plog.Errorf("error closing snapshot (%v)", err)
+			}
+		}
+		pw.Close()
+	}()
+
+	// send file data
+	h := sha256.New()
+	br := int64(0)
+	buf := make([]byte, 32*1024)
+	sz := snap.Size()
+	for br < sz {
+		n, err := io.ReadFull(pr, buf)
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			return togRPCError(err)
+		}
+		br += int64(n)
+		resp := &pb.SnapshotResponse{
+			RemainingBytes: uint64(sz - br),
+			Blob:           buf[:n],
+		}
+		if err = srv.Send(resp); err != nil {
+			return togRPCError(err)
+		}
+		h.Write(buf[:n])
+	}
+
+	// send sha
+	sha := h.Sum(nil)
+	hresp := &pb.SnapshotResponse{RemainingBytes: 0, Blob: sha}
+	if err := srv.Send(hresp); err != nil {
+		return togRPCError(err)
+	}
+
+	return nil
+}
+
+func (ms *maintenanceServer) Hash(ctx context.Context, r *pb.HashRequest) (*pb.HashResponse, error) {
+	h, rev, err := ms.kg.KV().Hash()
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	resp := &pb.HashResponse{Header: &pb.ResponseHeader{Revision: rev}, Hash: h}
+	ms.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ms *maintenanceServer) HashKV(ctx context.Context, r *pb.HashKVRequest) (*pb.HashKVResponse, error) {
+	h, rev, compactRev, err := ms.kg.KV().HashByRev(r.Revision)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	resp := &pb.HashKVResponse{Header: &pb.ResponseHeader{Revision: rev}, Hash: h, CompactRevision: compactRev}
+	ms.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ms *maintenanceServer) Alarm(ctx context.Context, ar *pb.AlarmRequest) (*pb.AlarmResponse, error) {
+	return ms.a.Alarm(ctx, ar)
+}
+
+func (ms *maintenanceServer) Status(ctx context.Context, ar *pb.StatusRequest) (*pb.StatusResponse, error) {
+	hdr := &pb.ResponseHeader{}
+	ms.hdr.fill(hdr)
+	resp := &pb.StatusResponse{
+		Header:           hdr,
+		Version:          version.Version,
+		Leader:           uint64(ms.rg.Leader()),
+		RaftIndex:        ms.rg.CommittedIndex(),
+		RaftAppliedIndex: ms.rg.AppliedIndex(),
+		RaftTerm:         ms.rg.Term(),
+		DbSize:           ms.bg.Backend().Size(),
+		DbSizeInUse:      ms.bg.Backend().SizeInUse(),
+		IsLearner:        ms.cs.IsLearner(),
+	}
+	if resp.Leader == raft.None {
+		resp.Errors = append(resp.Errors, etcdserver.ErrNoLeader.Error())
+	}
+	for _, a := range ms.a.Alarms() {
+		resp.Errors = append(resp.Errors, a.String())
+	}
+	return resp, nil
+}
+
+func (ms *maintenanceServer) MoveLeader(ctx context.Context, tr *pb.MoveLeaderRequest) (*pb.MoveLeaderResponse, error) {
+	if ms.rg.ID() != ms.rg.Leader() {
+		return nil, rpctypes.ErrGRPCNotLeader
+	}
+
+	if err := ms.lt.MoveLeader(ctx, uint64(ms.rg.Leader()), tr.TargetID); err != nil {
+		return nil, togRPCError(err)
+	}
+	return &pb.MoveLeaderResponse{}, nil
+}
+
+type authMaintenanceServer struct {
+	*maintenanceServer
+	ag AuthGetter
+}
+
+func (ams *authMaintenanceServer) isAuthenticated(ctx context.Context) error {
+	authInfo, err := ams.ag.AuthInfoFromCtx(ctx)
+	if err != nil {
+		return err
+	}
+
+	return ams.ag.AuthStore().IsAdminPermitted(authInfo)
+}
+
+func (ams *authMaintenanceServer) Defragment(ctx context.Context, sr *pb.DefragmentRequest) (*pb.DefragmentResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+
+	return ams.maintenanceServer.Defragment(ctx, sr)
+}
+
+func (ams *authMaintenanceServer) Snapshot(sr *pb.SnapshotRequest, srv pb.Maintenance_SnapshotServer) error {
+	if err := ams.isAuthenticated(srv.Context()); err != nil {
+		return err
+	}
+
+	return ams.maintenanceServer.Snapshot(sr, srv)
+}
+
+func (ams *authMaintenanceServer) Hash(ctx context.Context, r *pb.HashRequest) (*pb.HashResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+
+	return ams.maintenanceServer.Hash(ctx, r)
+}
+
+func (ams *authMaintenanceServer) HashKV(ctx context.Context, r *pb.HashKVRequest) (*pb.HashKVResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+	return ams.maintenanceServer.HashKV(ctx, r)
+}
+
+func (ams *authMaintenanceServer) Status(ctx context.Context, ar *pb.StatusRequest) (*pb.StatusResponse, error) {
+	return ams.maintenanceServer.Status(ctx, ar)
+}
+
+func (ams *authMaintenanceServer) MoveLeader(ctx context.Context, tr *pb.MoveLeaderRequest) (*pb.MoveLeaderResponse, error) {
+	return ams.maintenanceServer.MoveLeader(ctx, tr)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/member.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/member.go
new file mode 100644
index 0000000..b2ebc98
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/member.go
@@ -0,0 +1,119 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+)
+
+type ClusterServer struct {
+	cluster api.Cluster
+	server  etcdserver.ServerV3
+}
+
+func NewClusterServer(s etcdserver.ServerV3) *ClusterServer {
+	return &ClusterServer{
+		cluster: s.Cluster(),
+		server:  s,
+	}
+}
+
+func (cs *ClusterServer) MemberAdd(ctx context.Context, r *pb.MemberAddRequest) (*pb.MemberAddResponse, error) {
+	urls, err := types.NewURLs(r.PeerURLs)
+	if err != nil {
+		return nil, rpctypes.ErrGRPCMemberBadURLs
+	}
+
+	now := time.Now()
+	var m *membership.Member
+	if r.IsLearner {
+		m = membership.NewMemberAsLearner("", urls, "", &now)
+	} else {
+		m = membership.NewMember("", urls, "", &now)
+	}
+	membs, merr := cs.server.AddMember(ctx, *m)
+	if merr != nil {
+		return nil, togRPCError(merr)
+	}
+
+	return &pb.MemberAddResponse{
+		Header: cs.header(),
+		Member: &pb.Member{
+			ID:        uint64(m.ID),
+			PeerURLs:  m.PeerURLs,
+			IsLearner: m.IsLearner,
+		},
+		Members: membersToProtoMembers(membs),
+	}, nil
+}
+
+func (cs *ClusterServer) MemberRemove(ctx context.Context, r *pb.MemberRemoveRequest) (*pb.MemberRemoveResponse, error) {
+	membs, err := cs.server.RemoveMember(ctx, r.ID)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return &pb.MemberRemoveResponse{Header: cs.header(), Members: membersToProtoMembers(membs)}, nil
+}
+
+func (cs *ClusterServer) MemberUpdate(ctx context.Context, r *pb.MemberUpdateRequest) (*pb.MemberUpdateResponse, error) {
+	m := membership.Member{
+		ID:             types.ID(r.ID),
+		RaftAttributes: membership.RaftAttributes{PeerURLs: r.PeerURLs},
+	}
+	membs, err := cs.server.UpdateMember(ctx, m)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return &pb.MemberUpdateResponse{Header: cs.header(), Members: membersToProtoMembers(membs)}, nil
+}
+
+func (cs *ClusterServer) MemberList(ctx context.Context, r *pb.MemberListRequest) (*pb.MemberListResponse, error) {
+	membs := membersToProtoMembers(cs.cluster.Members())
+	return &pb.MemberListResponse{Header: cs.header(), Members: membs}, nil
+}
+
+func (cs *ClusterServer) MemberPromote(ctx context.Context, r *pb.MemberPromoteRequest) (*pb.MemberPromoteResponse, error) {
+	membs, err := cs.server.PromoteMember(ctx, r.ID)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	return &pb.MemberPromoteResponse{Header: cs.header(), Members: membersToProtoMembers(membs)}, nil
+}
+
+func (cs *ClusterServer) header() *pb.ResponseHeader {
+	return &pb.ResponseHeader{ClusterId: uint64(cs.cluster.ID()), MemberId: uint64(cs.server.ID()), RaftTerm: cs.server.Term()}
+}
+
+func membersToProtoMembers(membs []*membership.Member) []*pb.Member {
+	protoMembs := make([]*pb.Member, len(membs))
+	for i := range membs {
+		protoMembs[i] = &pb.Member{
+			Name:       membs[i].Name,
+			ID:         uint64(membs[i].ID),
+			PeerURLs:   membs[i].PeerURLs,
+			ClientURLs: membs[i].ClientURLs,
+			IsLearner:  membs[i].IsLearner,
+		}
+	}
+	return protoMembs
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/metrics.go
new file mode 100644
index 0000000..d633d27
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/metrics.go
@@ -0,0 +1,48 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	sentBytes = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "client_grpc_sent_bytes_total",
+		Help:      "The total number of bytes sent to grpc clients.",
+	})
+
+	receivedBytes = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "client_grpc_received_bytes_total",
+		Help:      "The total number of bytes received from grpc clients.",
+	})
+
+	streamFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "server_stream_failures_total",
+		Help:      "The total number of stream failures from the local server.",
+	},
+		[]string{"Type", "API"},
+	)
+)
+
+func init() {
+	prometheus.MustRegister(sentBytes)
+	prometheus.MustRegister(receivedBytes)
+	prometheus.MustRegister(streamFailures)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/quota.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/quota.go
new file mode 100644
index 0000000..a145b8b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/quota.go
@@ -0,0 +1,90 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+)
+
+type quotaKVServer struct {
+	pb.KVServer
+	qa quotaAlarmer
+}
+
+type quotaAlarmer struct {
+	q  etcdserver.Quota
+	a  Alarmer
+	id types.ID
+}
+
+// check whether request satisfies the quota. If there is not enough space,
+// ignore request and raise the free space alarm.
+func (qa *quotaAlarmer) check(ctx context.Context, r interface{}) error {
+	if qa.q.Available(r) {
+		return nil
+	}
+	req := &pb.AlarmRequest{
+		MemberID: uint64(qa.id),
+		Action:   pb.AlarmRequest_ACTIVATE,
+		Alarm:    pb.AlarmType_NOSPACE,
+	}
+	qa.a.Alarm(ctx, req)
+	return rpctypes.ErrGRPCNoSpace
+}
+
+func NewQuotaKVServer(s *etcdserver.EtcdServer) pb.KVServer {
+	return &quotaKVServer{
+		NewKVServer(s),
+		quotaAlarmer{etcdserver.NewBackendQuota(s, "kv"), s, s.ID()},
+	}
+}
+
+func (s *quotaKVServer) Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error) {
+	if err := s.qa.check(ctx, r); err != nil {
+		return nil, err
+	}
+	return s.KVServer.Put(ctx, r)
+}
+
+func (s *quotaKVServer) Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if err := s.qa.check(ctx, r); err != nil {
+		return nil, err
+	}
+	return s.KVServer.Txn(ctx, r)
+}
+
+type quotaLeaseServer struct {
+	pb.LeaseServer
+	qa quotaAlarmer
+}
+
+func (s *quotaLeaseServer) LeaseGrant(ctx context.Context, cr *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	if err := s.qa.check(ctx, cr); err != nil {
+		return nil, err
+	}
+	return s.LeaseServer.LeaseGrant(ctx, cr)
+}
+
+func NewQuotaLeaseServer(s *etcdserver.EtcdServer) pb.LeaseServer {
+	return &quotaLeaseServer{
+		NewLeaseServer(s),
+		quotaAlarmer{etcdserver.NewBackendQuota(s, "lease"), s, s.ID()},
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/util.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/util.go
new file mode 100644
index 0000000..281ddc7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/util.go
@@ -0,0 +1,136 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"strings"
+
+	"go.etcd.io/etcd/auth"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+var toGRPCErrorMap = map[error]error{
+	membership.ErrIDRemoved:               rpctypes.ErrGRPCMemberNotFound,
+	membership.ErrIDNotFound:              rpctypes.ErrGRPCMemberNotFound,
+	membership.ErrIDExists:                rpctypes.ErrGRPCMemberExist,
+	membership.ErrPeerURLexists:           rpctypes.ErrGRPCPeerURLExist,
+	membership.ErrMemberNotLearner:        rpctypes.ErrGRPCMemberNotLearner,
+	membership.ErrTooManyLearners:         rpctypes.ErrGRPCTooManyLearners,
+	etcdserver.ErrNotEnoughStartedMembers: rpctypes.ErrMemberNotEnoughStarted,
+	etcdserver.ErrLearnerNotReady:         rpctypes.ErrGRPCLearnerNotReady,
+
+	mvcc.ErrCompacted:             rpctypes.ErrGRPCCompacted,
+	mvcc.ErrFutureRev:             rpctypes.ErrGRPCFutureRev,
+	etcdserver.ErrRequestTooLarge: rpctypes.ErrGRPCRequestTooLarge,
+	etcdserver.ErrNoSpace:         rpctypes.ErrGRPCNoSpace,
+	etcdserver.ErrTooManyRequests: rpctypes.ErrTooManyRequests,
+
+	etcdserver.ErrNoLeader:                   rpctypes.ErrGRPCNoLeader,
+	etcdserver.ErrNotLeader:                  rpctypes.ErrGRPCNotLeader,
+	etcdserver.ErrLeaderChanged:              rpctypes.ErrGRPCLeaderChanged,
+	etcdserver.ErrStopped:                    rpctypes.ErrGRPCStopped,
+	etcdserver.ErrTimeout:                    rpctypes.ErrGRPCTimeout,
+	etcdserver.ErrTimeoutDueToLeaderFail:     rpctypes.ErrGRPCTimeoutDueToLeaderFail,
+	etcdserver.ErrTimeoutDueToConnectionLost: rpctypes.ErrGRPCTimeoutDueToConnectionLost,
+	etcdserver.ErrUnhealthy:                  rpctypes.ErrGRPCUnhealthy,
+	etcdserver.ErrKeyNotFound:                rpctypes.ErrGRPCKeyNotFound,
+	etcdserver.ErrCorrupt:                    rpctypes.ErrGRPCCorrupt,
+	etcdserver.ErrBadLeaderTransferee:        rpctypes.ErrGRPCBadLeaderTransferee,
+
+	lease.ErrLeaseNotFound:    rpctypes.ErrGRPCLeaseNotFound,
+	lease.ErrLeaseExists:      rpctypes.ErrGRPCLeaseExist,
+	lease.ErrLeaseTTLTooLarge: rpctypes.ErrGRPCLeaseTTLTooLarge,
+
+	auth.ErrRootUserNotExist:     rpctypes.ErrGRPCRootUserNotExist,
+	auth.ErrRootRoleNotExist:     rpctypes.ErrGRPCRootRoleNotExist,
+	auth.ErrUserAlreadyExist:     rpctypes.ErrGRPCUserAlreadyExist,
+	auth.ErrUserEmpty:            rpctypes.ErrGRPCUserEmpty,
+	auth.ErrUserNotFound:         rpctypes.ErrGRPCUserNotFound,
+	auth.ErrRoleAlreadyExist:     rpctypes.ErrGRPCRoleAlreadyExist,
+	auth.ErrRoleNotFound:         rpctypes.ErrGRPCRoleNotFound,
+	auth.ErrRoleEmpty:            rpctypes.ErrGRPCRoleEmpty,
+	auth.ErrAuthFailed:           rpctypes.ErrGRPCAuthFailed,
+	auth.ErrPermissionDenied:     rpctypes.ErrGRPCPermissionDenied,
+	auth.ErrRoleNotGranted:       rpctypes.ErrGRPCRoleNotGranted,
+	auth.ErrPermissionNotGranted: rpctypes.ErrGRPCPermissionNotGranted,
+	auth.ErrAuthNotEnabled:       rpctypes.ErrGRPCAuthNotEnabled,
+	auth.ErrInvalidAuthToken:     rpctypes.ErrGRPCInvalidAuthToken,
+	auth.ErrInvalidAuthMgmt:      rpctypes.ErrGRPCInvalidAuthMgmt,
+}
+
+func togRPCError(err error) error {
+	// let gRPC server convert to codes.Canceled, codes.DeadlineExceeded
+	if err == context.Canceled || err == context.DeadlineExceeded {
+		return err
+	}
+	grpcErr, ok := toGRPCErrorMap[err]
+	if !ok {
+		return status.Error(codes.Unknown, err.Error())
+	}
+	return grpcErr
+}
+
+func isClientCtxErr(ctxErr error, err error) bool {
+	if ctxErr != nil {
+		return true
+	}
+
+	ev, ok := status.FromError(err)
+	if !ok {
+		return false
+	}
+
+	switch ev.Code() {
+	case codes.Canceled, codes.DeadlineExceeded:
+		// client-side context cancel or deadline exceeded
+		// "rpc error: code = Canceled desc = context canceled"
+		// "rpc error: code = DeadlineExceeded desc = context deadline exceeded"
+		return true
+	case codes.Unavailable:
+		msg := ev.Message()
+		// client-side context cancel or deadline exceeded with TLS ("http2.errClientDisconnected")
+		// "rpc error: code = Unavailable desc = client disconnected"
+		if msg == "client disconnected" {
+			return true
+		}
+		// "grpc/transport.ClientTransport.CloseStream" on canceled streams
+		// "rpc error: code = Unavailable desc = stream error: stream ID 21; CANCEL")
+		if strings.HasPrefix(msg, "stream error: ") && strings.HasSuffix(msg, "; CANCEL") {
+			return true
+		}
+	}
+	return false
+}
+
+// in v3.4, learner is allowed to serve serializable read and endpoint status
+func isRPCSupportedForLearner(req interface{}) bool {
+	switch r := req.(type) {
+	case *pb.StatusRequest:
+		return true
+	case *pb.RangeRequest:
+		return r.Serializable
+	default:
+		return false
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/watch.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/watch.go
new file mode 100644
index 0000000..f41cb6c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3rpc/watch.go
@@ -0,0 +1,584 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v3rpc
+
+import (
+	"context"
+	"io"
+	"math/rand"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/auth"
+	"go.etcd.io/etcd/etcdserver"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+
+	"go.uber.org/zap"
+)
+
+type watchServer struct {
+	lg *zap.Logger
+
+	clusterID int64
+	memberID  int64
+
+	maxRequestBytes int
+
+	sg        etcdserver.RaftStatusGetter
+	watchable mvcc.WatchableKV
+	ag        AuthGetter
+}
+
+// NewWatchServer returns a new watch server.
+func NewWatchServer(s *etcdserver.EtcdServer) pb.WatchServer {
+	return &watchServer{
+		lg: s.Cfg.Logger,
+
+		clusterID: int64(s.Cluster().ID()),
+		memberID:  int64(s.ID()),
+
+		maxRequestBytes: int(s.Cfg.MaxRequestBytes + grpcOverheadBytes),
+
+		sg:        s,
+		watchable: s.Watchable(),
+		ag:        s,
+	}
+}
+
+var (
+	// External test can read this with GetProgressReportInterval()
+	// and change this to a small value to finish fast with
+	// SetProgressReportInterval().
+	progressReportInterval   = 10 * time.Minute
+	progressReportIntervalMu sync.RWMutex
+)
+
+// GetProgressReportInterval returns the current progress report interval (for testing).
+func GetProgressReportInterval() time.Duration {
+	progressReportIntervalMu.RLock()
+	interval := progressReportInterval
+	progressReportIntervalMu.RUnlock()
+
+	// add rand(1/10*progressReportInterval) as jitter so that etcdserver will not
+	// send progress notifications to watchers around the same time even when watchers
+	// are created around the same time (which is common when a client restarts itself).
+	jitter := time.Duration(rand.Int63n(int64(interval) / 10))
+
+	return interval + jitter
+}
+
+// SetProgressReportInterval updates the current progress report interval (for testing).
+func SetProgressReportInterval(newTimeout time.Duration) {
+	progressReportIntervalMu.Lock()
+	progressReportInterval = newTimeout
+	progressReportIntervalMu.Unlock()
+}
+
+// We send ctrl response inside the read loop. We do not want
+// send to block read, but we still want ctrl response we sent to
+// be serialized. Thus we use a buffered chan to solve the problem.
+// A small buffer should be OK for most cases, since we expect the
+// ctrl requests are infrequent.
+const ctrlStreamBufLen = 16
+
+// serverWatchStream is an etcd server side stream. It receives requests
+// from client side gRPC stream. It receives watch events from mvcc.WatchStream,
+// and creates responses that forwarded to gRPC stream.
+// It also forwards control message like watch created and canceled.
+type serverWatchStream struct {
+	lg *zap.Logger
+
+	clusterID int64
+	memberID  int64
+
+	maxRequestBytes int
+
+	sg        etcdserver.RaftStatusGetter
+	watchable mvcc.WatchableKV
+	ag        AuthGetter
+
+	gRPCStream  pb.Watch_WatchServer
+	watchStream mvcc.WatchStream
+	ctrlStream  chan *pb.WatchResponse
+
+	// mu protects progress, prevKV, fragment
+	mu sync.RWMutex
+	// tracks the watchID that stream might need to send progress to
+	// TODO: combine progress and prevKV into a single struct?
+	progress map[mvcc.WatchID]bool
+	// record watch IDs that need return previous key-value pair
+	prevKV map[mvcc.WatchID]bool
+	// records fragmented watch IDs
+	fragment map[mvcc.WatchID]bool
+
+	// closec indicates the stream is closed.
+	closec chan struct{}
+
+	// wg waits for the send loop to complete
+	wg sync.WaitGroup
+}
+
+func (ws *watchServer) Watch(stream pb.Watch_WatchServer) (err error) {
+	sws := serverWatchStream{
+		lg: ws.lg,
+
+		clusterID: ws.clusterID,
+		memberID:  ws.memberID,
+
+		maxRequestBytes: ws.maxRequestBytes,
+
+		sg:        ws.sg,
+		watchable: ws.watchable,
+		ag:        ws.ag,
+
+		gRPCStream:  stream,
+		watchStream: ws.watchable.NewWatchStream(),
+		// chan for sending control response like watcher created and canceled.
+		ctrlStream: make(chan *pb.WatchResponse, ctrlStreamBufLen),
+
+		progress: make(map[mvcc.WatchID]bool),
+		prevKV:   make(map[mvcc.WatchID]bool),
+		fragment: make(map[mvcc.WatchID]bool),
+
+		closec: make(chan struct{}),
+	}
+
+	sws.wg.Add(1)
+	go func() {
+		sws.sendLoop()
+		sws.wg.Done()
+	}()
+
+	errc := make(chan error, 1)
+	// Ideally recvLoop would also use sws.wg to signal its completion
+	// but when stream.Context().Done() is closed, the stream's recv
+	// may continue to block since it uses a different context, leading to
+	// deadlock when calling sws.close().
+	go func() {
+		if rerr := sws.recvLoop(); rerr != nil {
+			if isClientCtxErr(stream.Context().Err(), rerr) {
+				if sws.lg != nil {
+					sws.lg.Debug("failed to receive watch request from gRPC stream", zap.Error(rerr))
+				} else {
+					plog.Debugf("failed to receive watch request from gRPC stream (%q)", rerr.Error())
+				}
+			} else {
+				if sws.lg != nil {
+					sws.lg.Warn("failed to receive watch request from gRPC stream", zap.Error(rerr))
+				} else {
+					plog.Warningf("failed to receive watch request from gRPC stream (%q)", rerr.Error())
+				}
+				streamFailures.WithLabelValues("receive", "watch").Inc()
+			}
+			errc <- rerr
+		}
+	}()
+
+	select {
+	case err = <-errc:
+		close(sws.ctrlStream)
+
+	case <-stream.Context().Done():
+		err = stream.Context().Err()
+		// the only server-side cancellation is noleader for now.
+		if err == context.Canceled {
+			err = rpctypes.ErrGRPCNoLeader
+		}
+	}
+
+	sws.close()
+	return err
+}
+
+func (sws *serverWatchStream) isWatchPermitted(wcr *pb.WatchCreateRequest) bool {
+	authInfo, err := sws.ag.AuthInfoFromCtx(sws.gRPCStream.Context())
+	if err != nil {
+		return false
+	}
+	if authInfo == nil {
+		// if auth is enabled, IsRangePermitted() can cause an error
+		authInfo = &auth.AuthInfo{}
+	}
+	return sws.ag.AuthStore().IsRangePermitted(authInfo, wcr.Key, wcr.RangeEnd) == nil
+}
+
+func (sws *serverWatchStream) recvLoop() error {
+	for {
+		req, err := sws.gRPCStream.Recv()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+
+		switch uv := req.RequestUnion.(type) {
+		case *pb.WatchRequest_CreateRequest:
+			if uv.CreateRequest == nil {
+				break
+			}
+
+			creq := uv.CreateRequest
+			if len(creq.Key) == 0 {
+				// \x00 is the smallest key
+				creq.Key = []byte{0}
+			}
+			if len(creq.RangeEnd) == 0 {
+				// force nil since watchstream.Watch distinguishes
+				// between nil and []byte{} for single key / >=
+				creq.RangeEnd = nil
+			}
+			if len(creq.RangeEnd) == 1 && creq.RangeEnd[0] == 0 {
+				// support  >= key queries
+				creq.RangeEnd = []byte{}
+			}
+
+			if !sws.isWatchPermitted(creq) {
+				wr := &pb.WatchResponse{
+					Header:       sws.newResponseHeader(sws.watchStream.Rev()),
+					WatchId:      creq.WatchId,
+					Canceled:     true,
+					Created:      true,
+					CancelReason: rpctypes.ErrGRPCPermissionDenied.Error(),
+				}
+
+				select {
+				case sws.ctrlStream <- wr:
+				case <-sws.closec:
+				}
+				return nil
+			}
+
+			filters := FiltersFromRequest(creq)
+
+			wsrev := sws.watchStream.Rev()
+			rev := creq.StartRevision
+			if rev == 0 {
+				rev = wsrev + 1
+			}
+			id, err := sws.watchStream.Watch(mvcc.WatchID(creq.WatchId), creq.Key, creq.RangeEnd, rev, filters...)
+			if err == nil {
+				sws.mu.Lock()
+				if creq.ProgressNotify {
+					sws.progress[id] = true
+				}
+				if creq.PrevKv {
+					sws.prevKV[id] = true
+				}
+				if creq.Fragment {
+					sws.fragment[id] = true
+				}
+				sws.mu.Unlock()
+			}
+			wr := &pb.WatchResponse{
+				Header:   sws.newResponseHeader(wsrev),
+				WatchId:  int64(id),
+				Created:  true,
+				Canceled: err != nil,
+			}
+			if err != nil {
+				wr.CancelReason = err.Error()
+			}
+			select {
+			case sws.ctrlStream <- wr:
+			case <-sws.closec:
+				return nil
+			}
+
+		case *pb.WatchRequest_CancelRequest:
+			if uv.CancelRequest != nil {
+				id := uv.CancelRequest.WatchId
+				err := sws.watchStream.Cancel(mvcc.WatchID(id))
+				if err == nil {
+					sws.ctrlStream <- &pb.WatchResponse{
+						Header:   sws.newResponseHeader(sws.watchStream.Rev()),
+						WatchId:  id,
+						Canceled: true,
+					}
+					sws.mu.Lock()
+					delete(sws.progress, mvcc.WatchID(id))
+					delete(sws.prevKV, mvcc.WatchID(id))
+					delete(sws.fragment, mvcc.WatchID(id))
+					sws.mu.Unlock()
+				}
+			}
+		case *pb.WatchRequest_ProgressRequest:
+			if uv.ProgressRequest != nil {
+				sws.ctrlStream <- &pb.WatchResponse{
+					Header:  sws.newResponseHeader(sws.watchStream.Rev()),
+					WatchId: -1, // response is not associated with any WatchId and will be broadcast to all watch channels
+				}
+			}
+		default:
+			// we probably should not shutdown the entire stream when
+			// receive an valid command.
+			// so just do nothing instead.
+			continue
+		}
+	}
+}
+
+func (sws *serverWatchStream) sendLoop() {
+	// watch ids that are currently active
+	ids := make(map[mvcc.WatchID]struct{})
+	// watch responses pending on a watch id creation message
+	pending := make(map[mvcc.WatchID][]*pb.WatchResponse)
+
+	interval := GetProgressReportInterval()
+	progressTicker := time.NewTicker(interval)
+
+	defer func() {
+		progressTicker.Stop()
+		// drain the chan to clean up pending events
+		for ws := range sws.watchStream.Chan() {
+			mvcc.ReportEventReceived(len(ws.Events))
+		}
+		for _, wrs := range pending {
+			for _, ws := range wrs {
+				mvcc.ReportEventReceived(len(ws.Events))
+			}
+		}
+	}()
+
+	for {
+		select {
+		case wresp, ok := <-sws.watchStream.Chan():
+			if !ok {
+				return
+			}
+
+			// TODO: evs is []mvccpb.Event type
+			// either return []*mvccpb.Event from the mvcc package
+			// or define protocol buffer with []mvccpb.Event.
+			evs := wresp.Events
+			events := make([]*mvccpb.Event, len(evs))
+			sws.mu.RLock()
+			needPrevKV := sws.prevKV[wresp.WatchID]
+			sws.mu.RUnlock()
+			for i := range evs {
+				events[i] = &evs[i]
+				if needPrevKV {
+					opt := mvcc.RangeOptions{Rev: evs[i].Kv.ModRevision - 1}
+					r, err := sws.watchable.Range(evs[i].Kv.Key, nil, opt)
+					if err == nil && len(r.KVs) != 0 {
+						events[i].PrevKv = &(r.KVs[0])
+					}
+				}
+			}
+
+			canceled := wresp.CompactRevision != 0
+			wr := &pb.WatchResponse{
+				Header:          sws.newResponseHeader(wresp.Revision),
+				WatchId:         int64(wresp.WatchID),
+				Events:          events,
+				CompactRevision: wresp.CompactRevision,
+				Canceled:        canceled,
+			}
+
+			if _, okID := ids[wresp.WatchID]; !okID {
+				// buffer if id not yet announced
+				wrs := append(pending[wresp.WatchID], wr)
+				pending[wresp.WatchID] = wrs
+				continue
+			}
+
+			mvcc.ReportEventReceived(len(evs))
+
+			sws.mu.RLock()
+			fragmented, ok := sws.fragment[wresp.WatchID]
+			sws.mu.RUnlock()
+
+			var serr error
+			if !fragmented && !ok {
+				serr = sws.gRPCStream.Send(wr)
+			} else {
+				serr = sendFragments(wr, sws.maxRequestBytes, sws.gRPCStream.Send)
+			}
+
+			if serr != nil {
+				if isClientCtxErr(sws.gRPCStream.Context().Err(), serr) {
+					if sws.lg != nil {
+						sws.lg.Debug("failed to send watch response to gRPC stream", zap.Error(serr))
+					} else {
+						plog.Debugf("failed to send watch response to gRPC stream (%q)", serr.Error())
+					}
+				} else {
+					if sws.lg != nil {
+						sws.lg.Warn("failed to send watch response to gRPC stream", zap.Error(serr))
+					} else {
+						plog.Warningf("failed to send watch response to gRPC stream (%q)", serr.Error())
+					}
+					streamFailures.WithLabelValues("send", "watch").Inc()
+				}
+				return
+			}
+
+			sws.mu.Lock()
+			if len(evs) > 0 && sws.progress[wresp.WatchID] {
+				// elide next progress update if sent a key update
+				sws.progress[wresp.WatchID] = false
+			}
+			sws.mu.Unlock()
+
+		case c, ok := <-sws.ctrlStream:
+			if !ok {
+				return
+			}
+
+			if err := sws.gRPCStream.Send(c); err != nil {
+				if isClientCtxErr(sws.gRPCStream.Context().Err(), err) {
+					if sws.lg != nil {
+						sws.lg.Debug("failed to send watch control response to gRPC stream", zap.Error(err))
+					} else {
+						plog.Debugf("failed to send watch control response to gRPC stream (%q)", err.Error())
+					}
+				} else {
+					if sws.lg != nil {
+						sws.lg.Warn("failed to send watch control response to gRPC stream", zap.Error(err))
+					} else {
+						plog.Warningf("failed to send watch control response to gRPC stream (%q)", err.Error())
+					}
+					streamFailures.WithLabelValues("send", "watch").Inc()
+				}
+				return
+			}
+
+			// track id creation
+			wid := mvcc.WatchID(c.WatchId)
+			if c.Canceled {
+				delete(ids, wid)
+				continue
+			}
+			if c.Created {
+				// flush buffered events
+				ids[wid] = struct{}{}
+				for _, v := range pending[wid] {
+					mvcc.ReportEventReceived(len(v.Events))
+					if err := sws.gRPCStream.Send(v); err != nil {
+						if isClientCtxErr(sws.gRPCStream.Context().Err(), err) {
+							if sws.lg != nil {
+								sws.lg.Debug("failed to send pending watch response to gRPC stream", zap.Error(err))
+							} else {
+								plog.Debugf("failed to send pending watch response to gRPC stream (%q)", err.Error())
+							}
+						} else {
+							if sws.lg != nil {
+								sws.lg.Warn("failed to send pending watch response to gRPC stream", zap.Error(err))
+							} else {
+								plog.Warningf("failed to send pending watch response to gRPC stream (%q)", err.Error())
+							}
+							streamFailures.WithLabelValues("send", "watch").Inc()
+						}
+						return
+					}
+				}
+				delete(pending, wid)
+			}
+
+		case <-progressTicker.C:
+			sws.mu.Lock()
+			for id, ok := range sws.progress {
+				if ok {
+					sws.watchStream.RequestProgress(id)
+				}
+				sws.progress[id] = true
+			}
+			sws.mu.Unlock()
+
+		case <-sws.closec:
+			return
+		}
+	}
+}
+
+func sendFragments(
+	wr *pb.WatchResponse,
+	maxRequestBytes int,
+	sendFunc func(*pb.WatchResponse) error) error {
+	// no need to fragment if total request size is smaller
+	// than max request limit or response contains only one event
+	if wr.Size() < maxRequestBytes || len(wr.Events) < 2 {
+		return sendFunc(wr)
+	}
+
+	ow := *wr
+	ow.Events = make([]*mvccpb.Event, 0)
+	ow.Fragment = true
+
+	var idx int
+	for {
+		cur := ow
+		for _, ev := range wr.Events[idx:] {
+			cur.Events = append(cur.Events, ev)
+			if len(cur.Events) > 1 && cur.Size() >= maxRequestBytes {
+				cur.Events = cur.Events[:len(cur.Events)-1]
+				break
+			}
+			idx++
+		}
+		if idx == len(wr.Events) {
+			// last response has no more fragment
+			cur.Fragment = false
+		}
+		if err := sendFunc(&cur); err != nil {
+			return err
+		}
+		if !cur.Fragment {
+			break
+		}
+	}
+	return nil
+}
+
+func (sws *serverWatchStream) close() {
+	sws.watchStream.Close()
+	close(sws.closec)
+	sws.wg.Wait()
+}
+
+func (sws *serverWatchStream) newResponseHeader(rev int64) *pb.ResponseHeader {
+	return &pb.ResponseHeader{
+		ClusterId: uint64(sws.clusterID),
+		MemberId:  uint64(sws.memberID),
+		Revision:  rev,
+		RaftTerm:  sws.sg.Term(),
+	}
+}
+
+func filterNoDelete(e mvccpb.Event) bool {
+	return e.Type == mvccpb.DELETE
+}
+
+func filterNoPut(e mvccpb.Event) bool {
+	return e.Type == mvccpb.PUT
+}
+
+// FiltersFromRequest returns "mvcc.FilterFunc" from a given watch create request.
+func FiltersFromRequest(creq *pb.WatchCreateRequest) []mvcc.FilterFunc {
+	filters := make([]mvcc.FilterFunc, 0, len(creq.Filters))
+	for _, ft := range creq.Filters {
+		switch ft {
+		case pb.WatchCreateRequest_NOPUT:
+			filters = append(filters, filterNoPut)
+		case pb.WatchCreateRequest_NODELETE:
+			filters = append(filters, filterNoDelete)
+		default:
+		}
+	}
+	return filters
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/apply.go b/vendor/go.etcd.io/etcd/etcdserver/apply.go
new file mode 100644
index 0000000..1f06ad0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/apply.go
@@ -0,0 +1,1019 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"sort"
+	"time"
+
+	"go.etcd.io/etcd/auth"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/gogo/protobuf/proto"
+	"go.uber.org/zap"
+)
+
+const (
+	warnApplyDuration = 100 * time.Millisecond
+)
+
+type applyResult struct {
+	resp proto.Message
+	err  error
+	// physc signals the physical effect of the request has completed in addition
+	// to being logically reflected by the node. Currently only used for
+	// Compaction requests.
+	physc <-chan struct{}
+}
+
+// applierV3 is the interface for processing V3 raft messages
+type applierV3 interface {
+	Apply(r *pb.InternalRaftRequest) *applyResult
+
+	Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error)
+	Range(txn mvcc.TxnRead, r *pb.RangeRequest) (*pb.RangeResponse, error)
+	DeleteRange(txn mvcc.TxnWrite, dr *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error)
+	Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error)
+	Compaction(compaction *pb.CompactionRequest) (*pb.CompactionResponse, <-chan struct{}, error)
+
+	LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error)
+	LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error)
+
+	LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error)
+
+	Alarm(*pb.AlarmRequest) (*pb.AlarmResponse, error)
+
+	Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error)
+
+	AuthEnable() (*pb.AuthEnableResponse, error)
+	AuthDisable() (*pb.AuthDisableResponse, error)
+
+	UserAdd(ua *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
+	UserDelete(ua *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
+	UserChangePassword(ua *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error)
+	UserGrantRole(ua *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error)
+	UserGet(ua *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error)
+	UserRevokeRole(ua *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error)
+	RoleAdd(ua *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error)
+	RoleGrantPermission(ua *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error)
+	RoleGet(ua *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error)
+	RoleRevokePermission(ua *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error)
+	RoleDelete(ua *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
+	UserList(ua *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
+	RoleList(ua *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
+}
+
+type checkReqFunc func(mvcc.ReadView, *pb.RequestOp) error
+
+type applierV3backend struct {
+	s *EtcdServer
+
+	checkPut   checkReqFunc
+	checkRange checkReqFunc
+}
+
+func (s *EtcdServer) newApplierV3Backend() applierV3 {
+	base := &applierV3backend{s: s}
+	base.checkPut = func(rv mvcc.ReadView, req *pb.RequestOp) error {
+		return base.checkRequestPut(rv, req)
+	}
+	base.checkRange = func(rv mvcc.ReadView, req *pb.RequestOp) error {
+		return base.checkRequestRange(rv, req)
+	}
+	return base
+}
+
+func (s *EtcdServer) newApplierV3() applierV3 {
+	return newAuthApplierV3(
+		s.AuthStore(),
+		newQuotaApplierV3(s, s.newApplierV3Backend()),
+		s.lessor,
+	)
+}
+
+func (a *applierV3backend) Apply(r *pb.InternalRaftRequest) *applyResult {
+	ar := &applyResult{}
+	defer func(start time.Time) {
+		warnOfExpensiveRequest(a.s.getLogger(), start, &pb.InternalRaftStringer{Request: r}, ar.resp, ar.err)
+	}(time.Now())
+
+	// call into a.s.applyV3.F instead of a.F so upper appliers can check individual calls
+	switch {
+	case r.Range != nil:
+		ar.resp, ar.err = a.s.applyV3.Range(nil, r.Range)
+	case r.Put != nil:
+		ar.resp, ar.err = a.s.applyV3.Put(nil, r.Put)
+	case r.DeleteRange != nil:
+		ar.resp, ar.err = a.s.applyV3.DeleteRange(nil, r.DeleteRange)
+	case r.Txn != nil:
+		ar.resp, ar.err = a.s.applyV3.Txn(r.Txn)
+	case r.Compaction != nil:
+		ar.resp, ar.physc, ar.err = a.s.applyV3.Compaction(r.Compaction)
+	case r.LeaseGrant != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseGrant(r.LeaseGrant)
+	case r.LeaseRevoke != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseRevoke(r.LeaseRevoke)
+	case r.LeaseCheckpoint != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseCheckpoint(r.LeaseCheckpoint)
+	case r.Alarm != nil:
+		ar.resp, ar.err = a.s.applyV3.Alarm(r.Alarm)
+	case r.Authenticate != nil:
+		ar.resp, ar.err = a.s.applyV3.Authenticate(r.Authenticate)
+	case r.AuthEnable != nil:
+		ar.resp, ar.err = a.s.applyV3.AuthEnable()
+	case r.AuthDisable != nil:
+		ar.resp, ar.err = a.s.applyV3.AuthDisable()
+	case r.AuthUserAdd != nil:
+		ar.resp, ar.err = a.s.applyV3.UserAdd(r.AuthUserAdd)
+	case r.AuthUserDelete != nil:
+		ar.resp, ar.err = a.s.applyV3.UserDelete(r.AuthUserDelete)
+	case r.AuthUserChangePassword != nil:
+		ar.resp, ar.err = a.s.applyV3.UserChangePassword(r.AuthUserChangePassword)
+	case r.AuthUserGrantRole != nil:
+		ar.resp, ar.err = a.s.applyV3.UserGrantRole(r.AuthUserGrantRole)
+	case r.AuthUserGet != nil:
+		ar.resp, ar.err = a.s.applyV3.UserGet(r.AuthUserGet)
+	case r.AuthUserRevokeRole != nil:
+		ar.resp, ar.err = a.s.applyV3.UserRevokeRole(r.AuthUserRevokeRole)
+	case r.AuthRoleAdd != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleAdd(r.AuthRoleAdd)
+	case r.AuthRoleGrantPermission != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleGrantPermission(r.AuthRoleGrantPermission)
+	case r.AuthRoleGet != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleGet(r.AuthRoleGet)
+	case r.AuthRoleRevokePermission != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleRevokePermission(r.AuthRoleRevokePermission)
+	case r.AuthRoleDelete != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleDelete(r.AuthRoleDelete)
+	case r.AuthUserList != nil:
+		ar.resp, ar.err = a.s.applyV3.UserList(r.AuthUserList)
+	case r.AuthRoleList != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleList(r.AuthRoleList)
+	default:
+		panic("not implemented")
+	}
+	return ar
+}
+
+func (a *applierV3backend) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (resp *pb.PutResponse, err error) {
+	resp = &pb.PutResponse{}
+	resp.Header = &pb.ResponseHeader{}
+
+	val, leaseID := p.Value, lease.LeaseID(p.Lease)
+	if txn == nil {
+		if leaseID != lease.NoLease {
+			if l := a.s.lessor.Lookup(leaseID); l == nil {
+				return nil, lease.ErrLeaseNotFound
+			}
+		}
+		txn = a.s.KV().Write()
+		defer txn.End()
+	}
+
+	var rr *mvcc.RangeResult
+	if p.IgnoreValue || p.IgnoreLease || p.PrevKv {
+		rr, err = txn.Range(p.Key, nil, mvcc.RangeOptions{})
+		if err != nil {
+			return nil, err
+		}
+	}
+	if p.IgnoreValue || p.IgnoreLease {
+		if rr == nil || len(rr.KVs) == 0 {
+			// ignore_{lease,value} flag expects previous key-value pair
+			return nil, ErrKeyNotFound
+		}
+	}
+	if p.IgnoreValue {
+		val = rr.KVs[0].Value
+	}
+	if p.IgnoreLease {
+		leaseID = lease.LeaseID(rr.KVs[0].Lease)
+	}
+	if p.PrevKv {
+		if rr != nil && len(rr.KVs) != 0 {
+			resp.PrevKv = &rr.KVs[0]
+		}
+	}
+
+	resp.Header.Revision = txn.Put(p.Key, val, leaseID)
+	return resp, nil
+}
+
+func (a *applierV3backend) DeleteRange(txn mvcc.TxnWrite, dr *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	resp := &pb.DeleteRangeResponse{}
+	resp.Header = &pb.ResponseHeader{}
+	end := mkGteRange(dr.RangeEnd)
+
+	if txn == nil {
+		txn = a.s.kv.Write()
+		defer txn.End()
+	}
+
+	if dr.PrevKv {
+		rr, err := txn.Range(dr.Key, end, mvcc.RangeOptions{})
+		if err != nil {
+			return nil, err
+		}
+		if rr != nil {
+			resp.PrevKvs = make([]*mvccpb.KeyValue, len(rr.KVs))
+			for i := range rr.KVs {
+				resp.PrevKvs[i] = &rr.KVs[i]
+			}
+		}
+	}
+
+	resp.Deleted, resp.Header.Revision = txn.DeleteRange(dr.Key, end)
+	return resp, nil
+}
+
+func (a *applierV3backend) Range(txn mvcc.TxnRead, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	resp := &pb.RangeResponse{}
+	resp.Header = &pb.ResponseHeader{}
+
+	if txn == nil {
+		txn = a.s.kv.Read()
+		defer txn.End()
+	}
+
+	limit := r.Limit
+	if r.SortOrder != pb.RangeRequest_NONE ||
+		r.MinModRevision != 0 || r.MaxModRevision != 0 ||
+		r.MinCreateRevision != 0 || r.MaxCreateRevision != 0 {
+		// fetch everything; sort and truncate afterwards
+		limit = 0
+	}
+	if limit > 0 {
+		// fetch one extra for 'more' flag
+		limit = limit + 1
+	}
+
+	ro := mvcc.RangeOptions{
+		Limit: limit,
+		Rev:   r.Revision,
+		Count: r.CountOnly,
+	}
+
+	rr, err := txn.Range(r.Key, mkGteRange(r.RangeEnd), ro)
+	if err != nil {
+		return nil, err
+	}
+
+	if r.MaxModRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.ModRevision > r.MaxModRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MinModRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.ModRevision < r.MinModRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MaxCreateRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.CreateRevision > r.MaxCreateRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MinCreateRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.CreateRevision < r.MinCreateRevision }
+		pruneKVs(rr, f)
+	}
+
+	sortOrder := r.SortOrder
+	if r.SortTarget != pb.RangeRequest_KEY && sortOrder == pb.RangeRequest_NONE {
+		// Since current mvcc.Range implementation returns results
+		// sorted by keys in lexiographically ascending order,
+		// sort ASCEND by default only when target is not 'KEY'
+		sortOrder = pb.RangeRequest_ASCEND
+	}
+	if sortOrder != pb.RangeRequest_NONE {
+		var sorter sort.Interface
+		switch {
+		case r.SortTarget == pb.RangeRequest_KEY:
+			sorter = &kvSortByKey{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_VERSION:
+			sorter = &kvSortByVersion{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_CREATE:
+			sorter = &kvSortByCreate{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_MOD:
+			sorter = &kvSortByMod{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_VALUE:
+			sorter = &kvSortByValue{&kvSort{rr.KVs}}
+		}
+		switch {
+		case sortOrder == pb.RangeRequest_ASCEND:
+			sort.Sort(sorter)
+		case sortOrder == pb.RangeRequest_DESCEND:
+			sort.Sort(sort.Reverse(sorter))
+		}
+	}
+
+	if r.Limit > 0 && len(rr.KVs) > int(r.Limit) {
+		rr.KVs = rr.KVs[:r.Limit]
+		resp.More = true
+	}
+
+	resp.Header.Revision = rr.Rev
+	resp.Count = int64(rr.Count)
+	resp.Kvs = make([]*mvccpb.KeyValue, len(rr.KVs))
+	for i := range rr.KVs {
+		if r.KeysOnly {
+			rr.KVs[i].Value = nil
+		}
+		resp.Kvs[i] = &rr.KVs[i]
+	}
+	return resp, nil
+}
+
+func (a *applierV3backend) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	isWrite := !isTxnReadonly(rt)
+	txn := mvcc.NewReadOnlyTxnWrite(a.s.KV().Read())
+
+	txnPath := compareToPath(txn, rt)
+	if isWrite {
+		if _, err := checkRequests(txn, rt, txnPath, a.checkPut); err != nil {
+			txn.End()
+			return nil, err
+		}
+	}
+	if _, err := checkRequests(txn, rt, txnPath, a.checkRange); err != nil {
+		txn.End()
+		return nil, err
+	}
+
+	txnResp, _ := newTxnResp(rt, txnPath)
+
+	// When executing mutable txn ops, etcd must hold the txn lock so
+	// readers do not see any intermediate results. Since writes are
+	// serialized on the raft loop, the revision in the read view will
+	// be the revision of the write txn.
+	if isWrite {
+		txn.End()
+		txn = a.s.KV().Write()
+	}
+	a.applyTxn(txn, rt, txnPath, txnResp)
+	rev := txn.Rev()
+	if len(txn.Changes()) != 0 {
+		rev++
+	}
+	txn.End()
+
+	txnResp.Header.Revision = rev
+	return txnResp, nil
+}
+
+// newTxnResp allocates a txn response for a txn request given a path.
+func newTxnResp(rt *pb.TxnRequest, txnPath []bool) (txnResp *pb.TxnResponse, txnCount int) {
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+	resps := make([]*pb.ResponseOp, len(reqs))
+	txnResp = &pb.TxnResponse{
+		Responses: resps,
+		Succeeded: txnPath[0],
+		Header:    &pb.ResponseHeader{},
+	}
+	for i, req := range reqs {
+		switch tv := req.Request.(type) {
+		case *pb.RequestOp_RequestRange:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseRange{}}
+		case *pb.RequestOp_RequestPut:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponsePut{}}
+		case *pb.RequestOp_RequestDeleteRange:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseDeleteRange{}}
+		case *pb.RequestOp_RequestTxn:
+			resp, txns := newTxnResp(tv.RequestTxn, txnPath[1:])
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseTxn{ResponseTxn: resp}}
+			txnPath = txnPath[1+txns:]
+			txnCount += txns + 1
+		default:
+		}
+	}
+	return txnResp, txnCount
+}
+
+func compareToPath(rv mvcc.ReadView, rt *pb.TxnRequest) []bool {
+	txnPath := make([]bool, 1)
+	ops := rt.Success
+	if txnPath[0] = applyCompares(rv, rt.Compare); !txnPath[0] {
+		ops = rt.Failure
+	}
+	for _, op := range ops {
+		tv, ok := op.Request.(*pb.RequestOp_RequestTxn)
+		if !ok || tv.RequestTxn == nil {
+			continue
+		}
+		txnPath = append(txnPath, compareToPath(rv, tv.RequestTxn)...)
+	}
+	return txnPath
+}
+
+func applyCompares(rv mvcc.ReadView, cmps []*pb.Compare) bool {
+	for _, c := range cmps {
+		if !applyCompare(rv, c) {
+			return false
+		}
+	}
+	return true
+}
+
+// applyCompare applies the compare request.
+// If the comparison succeeds, it returns true. Otherwise, returns false.
+func applyCompare(rv mvcc.ReadView, c *pb.Compare) bool {
+	// TODO: possible optimizations
+	// * chunk reads for large ranges to conserve memory
+	// * rewrite rules for common patterns:
+	//	ex. "[a, b) createrev > 0" => "limit 1 /\ kvs > 0"
+	// * caching
+	rr, err := rv.Range(c.Key, mkGteRange(c.RangeEnd), mvcc.RangeOptions{})
+	if err != nil {
+		return false
+	}
+	if len(rr.KVs) == 0 {
+		if c.Target == pb.Compare_VALUE {
+			// Always fail if comparing a value on a key/keys that doesn't exist;
+			// nil == empty string in grpc; no way to represent missing value
+			return false
+		}
+		return compareKV(c, mvccpb.KeyValue{})
+	}
+	for _, kv := range rr.KVs {
+		if !compareKV(c, kv) {
+			return false
+		}
+	}
+	return true
+}
+
+func compareKV(c *pb.Compare, ckv mvccpb.KeyValue) bool {
+	var result int
+	rev := int64(0)
+	switch c.Target {
+	case pb.Compare_VALUE:
+		v := []byte{}
+		if tv, _ := c.TargetUnion.(*pb.Compare_Value); tv != nil {
+			v = tv.Value
+		}
+		result = bytes.Compare(ckv.Value, v)
+	case pb.Compare_CREATE:
+		if tv, _ := c.TargetUnion.(*pb.Compare_CreateRevision); tv != nil {
+			rev = tv.CreateRevision
+		}
+		result = compareInt64(ckv.CreateRevision, rev)
+	case pb.Compare_MOD:
+		if tv, _ := c.TargetUnion.(*pb.Compare_ModRevision); tv != nil {
+			rev = tv.ModRevision
+		}
+		result = compareInt64(ckv.ModRevision, rev)
+	case pb.Compare_VERSION:
+		if tv, _ := c.TargetUnion.(*pb.Compare_Version); tv != nil {
+			rev = tv.Version
+		}
+		result = compareInt64(ckv.Version, rev)
+	case pb.Compare_LEASE:
+		if tv, _ := c.TargetUnion.(*pb.Compare_Lease); tv != nil {
+			rev = tv.Lease
+		}
+		result = compareInt64(ckv.Lease, rev)
+	}
+	switch c.Result {
+	case pb.Compare_EQUAL:
+		return result == 0
+	case pb.Compare_NOT_EQUAL:
+		return result != 0
+	case pb.Compare_GREATER:
+		return result > 0
+	case pb.Compare_LESS:
+		return result < 0
+	}
+	return true
+}
+
+func (a *applierV3backend) applyTxn(txn mvcc.TxnWrite, rt *pb.TxnRequest, txnPath []bool, tresp *pb.TxnResponse) (txns int) {
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+
+	lg := a.s.getLogger()
+	for i, req := range reqs {
+		respi := tresp.Responses[i].Response
+		switch tv := req.Request.(type) {
+		case *pb.RequestOp_RequestRange:
+			resp, err := a.Range(txn, tv.RequestRange)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponseRange).ResponseRange = resp
+		case *pb.RequestOp_RequestPut:
+			resp, err := a.Put(txn, tv.RequestPut)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponsePut).ResponsePut = resp
+		case *pb.RequestOp_RequestDeleteRange:
+			resp, err := a.DeleteRange(txn, tv.RequestDeleteRange)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponseDeleteRange).ResponseDeleteRange = resp
+		case *pb.RequestOp_RequestTxn:
+			resp := respi.(*pb.ResponseOp_ResponseTxn).ResponseTxn
+			applyTxns := a.applyTxn(txn, tv.RequestTxn, txnPath[1:], resp)
+			txns += applyTxns + 1
+			txnPath = txnPath[applyTxns+1:]
+		default:
+			// empty union
+		}
+	}
+	return txns
+}
+
+func (a *applierV3backend) Compaction(compaction *pb.CompactionRequest) (*pb.CompactionResponse, <-chan struct{}, error) {
+	resp := &pb.CompactionResponse{}
+	resp.Header = &pb.ResponseHeader{}
+	ch, err := a.s.KV().Compact(compaction.Revision)
+	if err != nil {
+		return nil, ch, err
+	}
+	// get the current revision. which key to get is not important.
+	rr, _ := a.s.KV().Range([]byte("compaction"), nil, mvcc.RangeOptions{})
+	resp.Header.Revision = rr.Rev
+	return resp, ch, err
+}
+
+func (a *applierV3backend) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	l, err := a.s.lessor.Grant(lease.LeaseID(lc.ID), lc.TTL)
+	resp := &pb.LeaseGrantResponse{}
+	if err == nil {
+		resp.ID = int64(l.ID)
+		resp.TTL = l.TTL()
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	err := a.s.lessor.Revoke(lease.LeaseID(lc.ID))
+	return &pb.LeaseRevokeResponse{Header: newHeader(a.s)}, err
+}
+
+func (a *applierV3backend) LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error) {
+	for _, c := range lc.Checkpoints {
+		err := a.s.lessor.Checkpoint(lease.LeaseID(c.ID), c.Remaining_TTL)
+		if err != nil {
+			return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, err
+		}
+	}
+	return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) Alarm(ar *pb.AlarmRequest) (*pb.AlarmResponse, error) {
+	resp := &pb.AlarmResponse{}
+	oldCount := len(a.s.alarmStore.Get(ar.Alarm))
+
+	lg := a.s.getLogger()
+	switch ar.Action {
+	case pb.AlarmRequest_GET:
+		resp.Alarms = a.s.alarmStore.Get(ar.Alarm)
+	case pb.AlarmRequest_ACTIVATE:
+		m := a.s.alarmStore.Activate(types.ID(ar.MemberID), ar.Alarm)
+		if m == nil {
+			break
+		}
+		resp.Alarms = append(resp.Alarms, m)
+		activated := oldCount == 0 && len(a.s.alarmStore.Get(m.Alarm)) == 1
+		if !activated {
+			break
+		}
+
+		if lg != nil {
+			lg.Warn("alarm raised", zap.String("alarm", m.Alarm.String()), zap.String("from", types.ID(m.MemberID).String()))
+		} else {
+			plog.Warningf("alarm %v raised by peer %s", m.Alarm, types.ID(m.MemberID))
+		}
+		switch m.Alarm {
+		case pb.AlarmType_CORRUPT:
+			a.s.applyV3 = newApplierV3Corrupt(a)
+		case pb.AlarmType_NOSPACE:
+			a.s.applyV3 = newApplierV3Capped(a)
+		default:
+			if lg != nil {
+				lg.Warn("unimplemented alarm activation", zap.String("alarm", fmt.Sprintf("%+v", m)))
+			} else {
+				plog.Errorf("unimplemented alarm activation (%+v)", m)
+			}
+		}
+	case pb.AlarmRequest_DEACTIVATE:
+		m := a.s.alarmStore.Deactivate(types.ID(ar.MemberID), ar.Alarm)
+		if m == nil {
+			break
+		}
+		resp.Alarms = append(resp.Alarms, m)
+		deactivated := oldCount > 0 && len(a.s.alarmStore.Get(ar.Alarm)) == 0
+		if !deactivated {
+			break
+		}
+
+		switch m.Alarm {
+		case pb.AlarmType_NOSPACE, pb.AlarmType_CORRUPT:
+			// TODO: check kv hash before deactivating CORRUPT?
+			if lg != nil {
+				lg.Warn("alarm disarmed", zap.String("alarm", m.Alarm.String()), zap.String("from", types.ID(m.MemberID).String()))
+			} else {
+				plog.Infof("alarm disarmed %+v", ar)
+			}
+			a.s.applyV3 = a.s.newApplierV3()
+		default:
+			if lg != nil {
+				lg.Warn("unimplemented alarm deactivation", zap.String("alarm", fmt.Sprintf("%+v", m)))
+			} else {
+				plog.Errorf("unimplemented alarm deactivation (%+v)", m)
+			}
+		}
+	default:
+		return nil, nil
+	}
+	return resp, nil
+}
+
+type applierV3Capped struct {
+	applierV3
+	q backendQuota
+}
+
+// newApplierV3Capped creates an applyV3 that will reject Puts and transactions
+// with Puts so that the number of keys in the store is capped.
+func newApplierV3Capped(base applierV3) applierV3 { return &applierV3Capped{applierV3: base} }
+
+func (a *applierV3Capped) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error) {
+	return nil, ErrNoSpace
+}
+
+func (a *applierV3Capped) Txn(r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if a.q.Cost(r) > 0 {
+		return nil, ErrNoSpace
+	}
+	return a.applierV3.Txn(r)
+}
+
+func (a *applierV3Capped) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	return nil, ErrNoSpace
+}
+
+func (a *applierV3backend) AuthEnable() (*pb.AuthEnableResponse, error) {
+	err := a.s.AuthStore().AuthEnable()
+	if err != nil {
+		return nil, err
+	}
+	return &pb.AuthEnableResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) AuthDisable() (*pb.AuthDisableResponse, error) {
+	a.s.AuthStore().AuthDisable()
+	return &pb.AuthDisableResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error) {
+	ctx := context.WithValue(context.WithValue(a.s.ctx, auth.AuthenticateParamIndex{}, a.s.consistIndex.ConsistentIndex()), auth.AuthenticateParamSimpleTokenPrefix{}, r.SimpleToken)
+	resp, err := a.s.AuthStore().Authenticate(ctx, r.Name, r.Password)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error) {
+	resp, err := a.s.AuthStore().UserAdd(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	resp, err := a.s.AuthStore().UserDelete(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserChangePassword(r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error) {
+	resp, err := a.s.AuthStore().UserChangePassword(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserGrantRole(r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error) {
+	resp, err := a.s.AuthStore().UserGrantRole(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserGet(r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	resp, err := a.s.AuthStore().UserGet(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	resp, err := a.s.AuthStore().UserRevokeRole(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleAdd(r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error) {
+	resp, err := a.s.AuthStore().RoleAdd(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleGrantPermission(r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error) {
+	resp, err := a.s.AuthStore().RoleGrantPermission(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleGet(r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	resp, err := a.s.AuthStore().RoleGet(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error) {
+	resp, err := a.s.AuthStore().RoleRevokePermission(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	resp, err := a.s.AuthStore().RoleDelete(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserList(r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error) {
+	resp, err := a.s.AuthStore().UserList(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleList(r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error) {
+	resp, err := a.s.AuthStore().RoleList(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+type quotaApplierV3 struct {
+	applierV3
+	q Quota
+}
+
+func newQuotaApplierV3(s *EtcdServer, app applierV3) applierV3 {
+	return &quotaApplierV3{app, NewBackendQuota(s, "v3-applier")}
+}
+
+func (a *quotaApplierV3) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error) {
+	ok := a.q.Available(p)
+	resp, err := a.applierV3.Put(txn, p)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+func (a *quotaApplierV3) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	ok := a.q.Available(rt)
+	resp, err := a.applierV3.Txn(rt)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+func (a *quotaApplierV3) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	ok := a.q.Available(lc)
+	resp, err := a.applierV3.LeaseGrant(lc)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+type kvSort struct{ kvs []mvccpb.KeyValue }
+
+func (s *kvSort) Swap(i, j int) {
+	t := s.kvs[i]
+	s.kvs[i] = s.kvs[j]
+	s.kvs[j] = t
+}
+func (s *kvSort) Len() int { return len(s.kvs) }
+
+type kvSortByKey struct{ *kvSort }
+
+func (s *kvSortByKey) Less(i, j int) bool {
+	return bytes.Compare(s.kvs[i].Key, s.kvs[j].Key) < 0
+}
+
+type kvSortByVersion struct{ *kvSort }
+
+func (s *kvSortByVersion) Less(i, j int) bool {
+	return (s.kvs[i].Version - s.kvs[j].Version) < 0
+}
+
+type kvSortByCreate struct{ *kvSort }
+
+func (s *kvSortByCreate) Less(i, j int) bool {
+	return (s.kvs[i].CreateRevision - s.kvs[j].CreateRevision) < 0
+}
+
+type kvSortByMod struct{ *kvSort }
+
+func (s *kvSortByMod) Less(i, j int) bool {
+	return (s.kvs[i].ModRevision - s.kvs[j].ModRevision) < 0
+}
+
+type kvSortByValue struct{ *kvSort }
+
+func (s *kvSortByValue) Less(i, j int) bool {
+	return bytes.Compare(s.kvs[i].Value, s.kvs[j].Value) < 0
+}
+
+func checkRequests(rv mvcc.ReadView, rt *pb.TxnRequest, txnPath []bool, f checkReqFunc) (int, error) {
+	txnCount := 0
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+	for _, req := range reqs {
+		if tv, ok := req.Request.(*pb.RequestOp_RequestTxn); ok && tv.RequestTxn != nil {
+			txns, err := checkRequests(rv, tv.RequestTxn, txnPath[1:], f)
+			if err != nil {
+				return 0, err
+			}
+			txnCount += txns + 1
+			txnPath = txnPath[txns+1:]
+			continue
+		}
+		if err := f(rv, req); err != nil {
+			return 0, err
+		}
+	}
+	return txnCount, nil
+}
+
+func (a *applierV3backend) checkRequestPut(rv mvcc.ReadView, reqOp *pb.RequestOp) error {
+	tv, ok := reqOp.Request.(*pb.RequestOp_RequestPut)
+	if !ok || tv.RequestPut == nil {
+		return nil
+	}
+	req := tv.RequestPut
+	if req.IgnoreValue || req.IgnoreLease {
+		// expects previous key-value, error if not exist
+		rr, err := rv.Range(req.Key, nil, mvcc.RangeOptions{})
+		if err != nil {
+			return err
+		}
+		if rr == nil || len(rr.KVs) == 0 {
+			return ErrKeyNotFound
+		}
+	}
+	if lease.LeaseID(req.Lease) != lease.NoLease {
+		if l := a.s.lessor.Lookup(lease.LeaseID(req.Lease)); l == nil {
+			return lease.ErrLeaseNotFound
+		}
+	}
+	return nil
+}
+
+func (a *applierV3backend) checkRequestRange(rv mvcc.ReadView, reqOp *pb.RequestOp) error {
+	tv, ok := reqOp.Request.(*pb.RequestOp_RequestRange)
+	if !ok || tv.RequestRange == nil {
+		return nil
+	}
+	req := tv.RequestRange
+	switch {
+	case req.Revision == 0:
+		return nil
+	case req.Revision > rv.Rev():
+		return mvcc.ErrFutureRev
+	case req.Revision < rv.FirstRev():
+		return mvcc.ErrCompacted
+	}
+	return nil
+}
+
+func compareInt64(a, b int64) int {
+	switch {
+	case a < b:
+		return -1
+	case a > b:
+		return 1
+	default:
+		return 0
+	}
+}
+
+// mkGteRange determines if the range end is a >= range. This works around grpc
+// sending empty byte strings as nil; >= is encoded in the range end as '\0'.
+// If it is a GTE range, then []byte{} is returned to indicate the empty byte
+// string (vs nil being no byte string).
+func mkGteRange(rangeEnd []byte) []byte {
+	if len(rangeEnd) == 1 && rangeEnd[0] == 0 {
+		return []byte{}
+	}
+	return rangeEnd
+}
+
+func noSideEffect(r *pb.InternalRaftRequest) bool {
+	return r.Range != nil || r.AuthUserGet != nil || r.AuthRoleGet != nil
+}
+
+func removeNeedlessRangeReqs(txn *pb.TxnRequest) {
+	f := func(ops []*pb.RequestOp) []*pb.RequestOp {
+		j := 0
+		for i := 0; i < len(ops); i++ {
+			if _, ok := ops[i].Request.(*pb.RequestOp_RequestRange); ok {
+				continue
+			}
+			ops[j] = ops[i]
+			j++
+		}
+
+		return ops[:j]
+	}
+
+	txn.Success = f(txn.Success)
+	txn.Failure = f(txn.Failure)
+}
+
+func pruneKVs(rr *mvcc.RangeResult, isPrunable func(*mvccpb.KeyValue) bool) {
+	j := 0
+	for i := range rr.KVs {
+		rr.KVs[j] = rr.KVs[i]
+		if !isPrunable(&rr.KVs[i]) {
+			j++
+		}
+	}
+	rr.KVs = rr.KVs[:j]
+}
+
+func newHeader(s *EtcdServer) *pb.ResponseHeader {
+	return &pb.ResponseHeader{
+		ClusterId: uint64(s.Cluster().ID()),
+		MemberId:  uint64(s.ID()),
+		Revision:  s.KV().Rev(),
+		RaftTerm:  s.Term(),
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/apply_auth.go b/vendor/go.etcd.io/etcd/etcdserver/apply_auth.go
new file mode 100644
index 0000000..4b094ad
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/apply_auth.go
@@ -0,0 +1,242 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"sync"
+
+	"go.etcd.io/etcd/auth"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+)
+
+type authApplierV3 struct {
+	applierV3
+	as     auth.AuthStore
+	lessor lease.Lessor
+
+	// mu serializes Apply so that user isn't corrupted and so that
+	// serialized requests don't leak data from TOCTOU errors
+	mu sync.Mutex
+
+	authInfo auth.AuthInfo
+}
+
+func newAuthApplierV3(as auth.AuthStore, base applierV3, lessor lease.Lessor) *authApplierV3 {
+	return &authApplierV3{applierV3: base, as: as, lessor: lessor}
+}
+
+func (aa *authApplierV3) Apply(r *pb.InternalRaftRequest) *applyResult {
+	aa.mu.Lock()
+	defer aa.mu.Unlock()
+	if r.Header != nil {
+		// backward-compatible with pre-3.0 releases when internalRaftRequest
+		// does not have header field
+		aa.authInfo.Username = r.Header.Username
+		aa.authInfo.Revision = r.Header.AuthRevision
+	}
+	if needAdminPermission(r) {
+		if err := aa.as.IsAdminPermitted(&aa.authInfo); err != nil {
+			aa.authInfo.Username = ""
+			aa.authInfo.Revision = 0
+			return &applyResult{err: err}
+		}
+	}
+	ret := aa.applierV3.Apply(r)
+	aa.authInfo.Username = ""
+	aa.authInfo.Revision = 0
+	return ret
+}
+
+func (aa *authApplierV3) Put(txn mvcc.TxnWrite, r *pb.PutRequest) (*pb.PutResponse, error) {
+	if err := aa.as.IsPutPermitted(&aa.authInfo, r.Key); err != nil {
+		return nil, err
+	}
+
+	if err := aa.checkLeasePuts(lease.LeaseID(r.Lease)); err != nil {
+		// The specified lease is already attached with a key that cannot
+		// be written by this user. It means the user cannot revoke the
+		// lease so attaching the lease to the newly written key should
+		// be forbidden.
+		return nil, err
+	}
+
+	if r.PrevKv {
+		err := aa.as.IsRangePermitted(&aa.authInfo, r.Key, nil)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return aa.applierV3.Put(txn, r)
+}
+
+func (aa *authApplierV3) Range(txn mvcc.TxnRead, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	if err := aa.as.IsRangePermitted(&aa.authInfo, r.Key, r.RangeEnd); err != nil {
+		return nil, err
+	}
+	return aa.applierV3.Range(txn, r)
+}
+
+func (aa *authApplierV3) DeleteRange(txn mvcc.TxnWrite, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	if err := aa.as.IsDeleteRangePermitted(&aa.authInfo, r.Key, r.RangeEnd); err != nil {
+		return nil, err
+	}
+	if r.PrevKv {
+		err := aa.as.IsRangePermitted(&aa.authInfo, r.Key, r.RangeEnd)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return aa.applierV3.DeleteRange(txn, r)
+}
+
+func checkTxnReqsPermission(as auth.AuthStore, ai *auth.AuthInfo, reqs []*pb.RequestOp) error {
+	for _, requ := range reqs {
+		switch tv := requ.Request.(type) {
+		case *pb.RequestOp_RequestRange:
+			if tv.RequestRange == nil {
+				continue
+			}
+
+			if err := as.IsRangePermitted(ai, tv.RequestRange.Key, tv.RequestRange.RangeEnd); err != nil {
+				return err
+			}
+
+		case *pb.RequestOp_RequestPut:
+			if tv.RequestPut == nil {
+				continue
+			}
+
+			if err := as.IsPutPermitted(ai, tv.RequestPut.Key); err != nil {
+				return err
+			}
+
+		case *pb.RequestOp_RequestDeleteRange:
+			if tv.RequestDeleteRange == nil {
+				continue
+			}
+
+			if tv.RequestDeleteRange.PrevKv {
+				err := as.IsRangePermitted(ai, tv.RequestDeleteRange.Key, tv.RequestDeleteRange.RangeEnd)
+				if err != nil {
+					return err
+				}
+			}
+
+			err := as.IsDeleteRangePermitted(ai, tv.RequestDeleteRange.Key, tv.RequestDeleteRange.RangeEnd)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func checkTxnAuth(as auth.AuthStore, ai *auth.AuthInfo, rt *pb.TxnRequest) error {
+	for _, c := range rt.Compare {
+		if err := as.IsRangePermitted(ai, c.Key, c.RangeEnd); err != nil {
+			return err
+		}
+	}
+	if err := checkTxnReqsPermission(as, ai, rt.Success); err != nil {
+		return err
+	}
+	return checkTxnReqsPermission(as, ai, rt.Failure)
+}
+
+func (aa *authApplierV3) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if err := checkTxnAuth(aa.as, &aa.authInfo, rt); err != nil {
+		return nil, err
+	}
+	return aa.applierV3.Txn(rt)
+}
+
+func (aa *authApplierV3) LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	if err := aa.checkLeasePuts(lease.LeaseID(lc.ID)); err != nil {
+		return nil, err
+	}
+	return aa.applierV3.LeaseRevoke(lc)
+}
+
+func (aa *authApplierV3) checkLeasePuts(leaseID lease.LeaseID) error {
+	lease := aa.lessor.Lookup(leaseID)
+	if lease != nil {
+		for _, key := range lease.Keys() {
+			if err := aa.as.IsPutPermitted(&aa.authInfo, []byte(key)); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (aa *authApplierV3) UserGet(r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	err := aa.as.IsAdminPermitted(&aa.authInfo)
+	if err != nil && r.Name != aa.authInfo.Username {
+		aa.authInfo.Username = ""
+		aa.authInfo.Revision = 0
+		return &pb.AuthUserGetResponse{}, err
+	}
+
+	return aa.applierV3.UserGet(r)
+}
+
+func (aa *authApplierV3) RoleGet(r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	err := aa.as.IsAdminPermitted(&aa.authInfo)
+	if err != nil && !aa.as.HasRole(aa.authInfo.Username, r.Role) {
+		aa.authInfo.Username = ""
+		aa.authInfo.Revision = 0
+		return &pb.AuthRoleGetResponse{}, err
+	}
+
+	return aa.applierV3.RoleGet(r)
+}
+
+func needAdminPermission(r *pb.InternalRaftRequest) bool {
+	switch {
+	case r.AuthEnable != nil:
+		return true
+	case r.AuthDisable != nil:
+		return true
+	case r.AuthUserAdd != nil:
+		return true
+	case r.AuthUserDelete != nil:
+		return true
+	case r.AuthUserChangePassword != nil:
+		return true
+	case r.AuthUserGrantRole != nil:
+		return true
+	case r.AuthUserRevokeRole != nil:
+		return true
+	case r.AuthRoleAdd != nil:
+		return true
+	case r.AuthRoleGrantPermission != nil:
+		return true
+	case r.AuthRoleRevokePermission != nil:
+		return true
+	case r.AuthRoleDelete != nil:
+		return true
+	case r.AuthUserList != nil:
+		return true
+	case r.AuthRoleList != nil:
+		return true
+	default:
+		return false
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/apply_v2.go b/vendor/go.etcd.io/etcd/etcdserver/apply_v2.go
new file mode 100644
index 0000000..c77df19
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/apply_v2.go
@@ -0,0 +1,147 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"encoding/json"
+	"path"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/pkg/pbutil"
+
+	"github.com/coreos/go-semver/semver"
+	"go.uber.org/zap"
+)
+
+// ApplierV2 is the interface for processing V2 raft messages
+type ApplierV2 interface {
+	Delete(r *RequestV2) Response
+	Post(r *RequestV2) Response
+	Put(r *RequestV2) Response
+	QGet(r *RequestV2) Response
+	Sync(r *RequestV2) Response
+}
+
+func NewApplierV2(lg *zap.Logger, s v2store.Store, c *membership.RaftCluster) ApplierV2 {
+	return &applierV2store{lg: lg, store: s, cluster: c}
+}
+
+type applierV2store struct {
+	lg      *zap.Logger
+	store   v2store.Store
+	cluster *membership.RaftCluster
+}
+
+func (a *applierV2store) Delete(r *RequestV2) Response {
+	switch {
+	case r.PrevIndex > 0 || r.PrevValue != "":
+		return toResponse(a.store.CompareAndDelete(r.Path, r.PrevValue, r.PrevIndex))
+	default:
+		return toResponse(a.store.Delete(r.Path, r.Dir, r.Recursive))
+	}
+}
+
+func (a *applierV2store) Post(r *RequestV2) Response {
+	return toResponse(a.store.Create(r.Path, r.Dir, r.Val, true, r.TTLOptions()))
+}
+
+func (a *applierV2store) Put(r *RequestV2) Response {
+	ttlOptions := r.TTLOptions()
+	exists, existsSet := pbutil.GetBool(r.PrevExist)
+	switch {
+	case existsSet:
+		if exists {
+			if r.PrevIndex == 0 && r.PrevValue == "" {
+				return toResponse(a.store.Update(r.Path, r.Val, ttlOptions))
+			}
+			return toResponse(a.store.CompareAndSwap(r.Path, r.PrevValue, r.PrevIndex, r.Val, ttlOptions))
+		}
+		return toResponse(a.store.Create(r.Path, r.Dir, r.Val, false, ttlOptions))
+	case r.PrevIndex > 0 || r.PrevValue != "":
+		return toResponse(a.store.CompareAndSwap(r.Path, r.PrevValue, r.PrevIndex, r.Val, ttlOptions))
+	default:
+		if storeMemberAttributeRegexp.MatchString(r.Path) {
+			id := membership.MustParseMemberIDFromKey(path.Dir(r.Path))
+			var attr membership.Attributes
+			if err := json.Unmarshal([]byte(r.Val), &attr); err != nil {
+				if a.lg != nil {
+					a.lg.Panic("failed to unmarshal", zap.String("value", r.Val), zap.Error(err))
+				} else {
+					plog.Panicf("unmarshal %s should never fail: %v", r.Val, err)
+				}
+			}
+			if a.cluster != nil {
+				a.cluster.UpdateAttributes(id, attr)
+			}
+			// return an empty response since there is no consumer.
+			return Response{}
+		}
+		if r.Path == membership.StoreClusterVersionKey() {
+			if a.cluster != nil {
+				a.cluster.SetVersion(semver.Must(semver.NewVersion(r.Val)), api.UpdateCapability)
+			}
+			// return an empty response since there is no consumer.
+			return Response{}
+		}
+		return toResponse(a.store.Set(r.Path, r.Dir, r.Val, ttlOptions))
+	}
+}
+
+func (a *applierV2store) QGet(r *RequestV2) Response {
+	return toResponse(a.store.Get(r.Path, r.Recursive, r.Sorted))
+}
+
+func (a *applierV2store) Sync(r *RequestV2) Response {
+	a.store.DeleteExpiredKeys(time.Unix(0, r.Time))
+	return Response{}
+}
+
+// applyV2Request interprets r as a call to v2store.X
+// and returns a Response interpreted from v2store.Event
+func (s *EtcdServer) applyV2Request(r *RequestV2) Response {
+	defer warnOfExpensiveRequest(s.getLogger(), time.Now(), r, nil, nil)
+
+	switch r.Method {
+	case "POST":
+		return s.applyV2.Post(r)
+	case "PUT":
+		return s.applyV2.Put(r)
+	case "DELETE":
+		return s.applyV2.Delete(r)
+	case "QGET":
+		return s.applyV2.QGet(r)
+	case "SYNC":
+		return s.applyV2.Sync(r)
+	default:
+		// This should never be reached, but just in case:
+		return Response{Err: ErrUnknownMethod}
+	}
+}
+
+func (r *RequestV2) TTLOptions() v2store.TTLOptionSet {
+	refresh, _ := pbutil.GetBool(r.Refresh)
+	ttlOptions := v2store.TTLOptionSet{Refresh: refresh}
+	if r.Expiration != 0 {
+		ttlOptions.ExpireTime = time.Unix(0, r.Expiration)
+	}
+	return ttlOptions
+}
+
+func toResponse(ev *v2store.Event, err error) Response {
+	return Response{Event: ev, Err: err}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/backend.go b/vendor/go.etcd.io/etcd/etcdserver/backend.go
new file mode 100644
index 0000000..01ba192
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/backend.go
@@ -0,0 +1,112 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	"go.uber.org/zap"
+)
+
+func newBackend(cfg ServerConfig) backend.Backend {
+	bcfg := backend.DefaultBackendConfig()
+	bcfg.Path = cfg.backendPath()
+	if cfg.BackendBatchLimit != 0 {
+		bcfg.BatchLimit = cfg.BackendBatchLimit
+		if cfg.Logger != nil {
+			cfg.Logger.Info("setting backend batch limit", zap.Int("batch limit", cfg.BackendBatchLimit))
+		}
+	}
+	if cfg.BackendBatchInterval != 0 {
+		bcfg.BatchInterval = cfg.BackendBatchInterval
+		if cfg.Logger != nil {
+			cfg.Logger.Info("setting backend batch interval", zap.Duration("batch interval", cfg.BackendBatchInterval))
+		}
+	}
+	bcfg.BackendFreelistType = cfg.BackendFreelistType
+	bcfg.Logger = cfg.Logger
+	if cfg.QuotaBackendBytes > 0 && cfg.QuotaBackendBytes != DefaultQuotaBytes {
+		// permit 10% excess over quota for disarm
+		bcfg.MmapSize = uint64(cfg.QuotaBackendBytes + cfg.QuotaBackendBytes/10)
+	}
+	return backend.New(bcfg)
+}
+
+// openSnapshotBackend renames a snapshot db to the current etcd db and opens it.
+func openSnapshotBackend(cfg ServerConfig, ss *snap.Snapshotter, snapshot raftpb.Snapshot) (backend.Backend, error) {
+	snapPath, err := ss.DBFilePath(snapshot.Metadata.Index)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find database snapshot file (%v)", err)
+	}
+	if err := os.Rename(snapPath, cfg.backendPath()); err != nil {
+		return nil, fmt.Errorf("failed to rename database snapshot file (%v)", err)
+	}
+	return openBackend(cfg), nil
+}
+
+// openBackend returns a backend using the current etcd db.
+func openBackend(cfg ServerConfig) backend.Backend {
+	fn := cfg.backendPath()
+
+	now, beOpened := time.Now(), make(chan backend.Backend)
+	go func() {
+		beOpened <- newBackend(cfg)
+	}()
+
+	select {
+	case be := <-beOpened:
+		if cfg.Logger != nil {
+			cfg.Logger.Info("opened backend db", zap.String("path", fn), zap.Duration("took", time.Since(now)))
+		}
+		return be
+
+	case <-time.After(10 * time.Second):
+		if cfg.Logger != nil {
+			cfg.Logger.Info(
+				"db file is flocked by another process, or taking too long",
+				zap.String("path", fn),
+				zap.Duration("took", time.Since(now)),
+			)
+		} else {
+			plog.Warningf("another etcd process is using %q and holds the file lock, or loading backend file is taking >10 seconds", fn)
+			plog.Warningf("waiting for it to exit before starting...")
+		}
+	}
+
+	return <-beOpened
+}
+
+// recoverBackendSnapshot recovers the DB from a snapshot in case etcd crashes
+// before updating the backend db after persisting raft snapshot to disk,
+// violating the invariant snapshot.Metadata.Index < db.consistentIndex. In this
+// case, replace the db with the snapshot db sent by the leader.
+func recoverSnapshotBackend(cfg ServerConfig, oldbe backend.Backend, snapshot raftpb.Snapshot) (backend.Backend, error) {
+	var cIndex consistentIndex
+	kv := mvcc.New(cfg.Logger, oldbe, &lease.FakeLessor{}, &cIndex, mvcc.StoreConfig{CompactionBatchLimit: cfg.CompactionBatchLimit})
+	defer kv.Close()
+	if snapshot.Metadata.Index <= kv.ConsistentIndex() {
+		return oldbe, nil
+	}
+	oldbe.Close()
+	return openSnapshotBackend(cfg, snap.New(cfg.Logger, cfg.SnapDir()), snapshot)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/cluster_util.go b/vendor/go.etcd.io/etcd/etcdserver/cluster_util.go
new file mode 100644
index 0000000..f92706c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/cluster_util.go
@@ -0,0 +1,407 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/version"
+
+	"github.com/coreos/go-semver/semver"
+	"go.uber.org/zap"
+)
+
+// isMemberBootstrapped tries to check if the given member has been bootstrapped
+// in the given cluster.
+func isMemberBootstrapped(lg *zap.Logger, cl *membership.RaftCluster, member string, rt http.RoundTripper, timeout time.Duration) bool {
+	rcl, err := getClusterFromRemotePeers(lg, getRemotePeerURLs(cl, member), timeout, false, rt)
+	if err != nil {
+		return false
+	}
+	id := cl.MemberByName(member).ID
+	m := rcl.Member(id)
+	if m == nil {
+		return false
+	}
+	if len(m.ClientURLs) > 0 {
+		return true
+	}
+	return false
+}
+
+// GetClusterFromRemotePeers takes a set of URLs representing etcd peers, and
+// attempts to construct a Cluster by accessing the members endpoint on one of
+// these URLs. The first URL to provide a response is used. If no URLs provide
+// a response, or a Cluster cannot be successfully created from a received
+// response, an error is returned.
+// Each request has a 10-second timeout. Because the upper limit of TTL is 5s,
+// 10 second is enough for building connection and finishing request.
+func GetClusterFromRemotePeers(lg *zap.Logger, urls []string, rt http.RoundTripper) (*membership.RaftCluster, error) {
+	return getClusterFromRemotePeers(lg, urls, 10*time.Second, true, rt)
+}
+
+// If logerr is true, it prints out more error messages.
+func getClusterFromRemotePeers(lg *zap.Logger, urls []string, timeout time.Duration, logerr bool, rt http.RoundTripper) (*membership.RaftCluster, error) {
+	cc := &http.Client{
+		Transport: rt,
+		Timeout:   timeout,
+	}
+	for _, u := range urls {
+		addr := u + "/members"
+		resp, err := cc.Get(addr)
+		if err != nil {
+			if logerr {
+				if lg != nil {
+					lg.Warn("failed to get cluster response", zap.String("address", addr), zap.Error(err))
+				} else {
+					plog.Warningf("could not get cluster response from %s: %v", u, err)
+				}
+			}
+			continue
+		}
+		b, err := ioutil.ReadAll(resp.Body)
+		resp.Body.Close()
+		if err != nil {
+			if logerr {
+				if lg != nil {
+					lg.Warn("failed to read body of cluster response", zap.String("address", addr), zap.Error(err))
+				} else {
+					plog.Warningf("could not read the body of cluster response: %v", err)
+				}
+			}
+			continue
+		}
+		var membs []*membership.Member
+		if err = json.Unmarshal(b, &membs); err != nil {
+			if logerr {
+				if lg != nil {
+					lg.Warn("failed to unmarshal cluster response", zap.String("address", addr), zap.Error(err))
+				} else {
+					plog.Warningf("could not unmarshal cluster response: %v", err)
+				}
+			}
+			continue
+		}
+		id, err := types.IDFromString(resp.Header.Get("X-Etcd-Cluster-ID"))
+		if err != nil {
+			if logerr {
+				if lg != nil {
+					lg.Warn(
+						"failed to parse cluster ID",
+						zap.String("address", addr),
+						zap.String("header", resp.Header.Get("X-Etcd-Cluster-ID")),
+						zap.Error(err),
+					)
+				} else {
+					plog.Warningf("could not parse the cluster ID from cluster res: %v", err)
+				}
+			}
+			continue
+		}
+
+		// check the length of membership members
+		// if the membership members are present then prepare and return raft cluster
+		// if membership members are not present then the raft cluster formed will be
+		// an invalid empty cluster hence return failed to get raft cluster member(s) from the given urls error
+		if len(membs) > 0 {
+			return membership.NewClusterFromMembers(lg, "", id, membs), nil
+		}
+		return nil, fmt.Errorf("failed to get raft cluster member(s) from the given URLs")
+	}
+	return nil, fmt.Errorf("could not retrieve cluster information from the given URLs")
+}
+
+// getRemotePeerURLs returns peer urls of remote members in the cluster. The
+// returned list is sorted in ascending lexicographical order.
+func getRemotePeerURLs(cl *membership.RaftCluster, local string) []string {
+	us := make([]string, 0)
+	for _, m := range cl.Members() {
+		if m.Name == local {
+			continue
+		}
+		us = append(us, m.PeerURLs...)
+	}
+	sort.Strings(us)
+	return us
+}
+
+// getVersions returns the versions of the members in the given cluster.
+// The key of the returned map is the member's ID. The value of the returned map
+// is the semver versions string, including server and cluster.
+// If it fails to get the version of a member, the key will be nil.
+func getVersions(lg *zap.Logger, cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) map[string]*version.Versions {
+	members := cl.Members()
+	vers := make(map[string]*version.Versions)
+	for _, m := range members {
+		if m.ID == local {
+			cv := "not_decided"
+			if cl.Version() != nil {
+				cv = cl.Version().String()
+			}
+			vers[m.ID.String()] = &version.Versions{Server: version.Version, Cluster: cv}
+			continue
+		}
+		ver, err := getVersion(lg, m, rt)
+		if err != nil {
+			if lg != nil {
+				lg.Warn("failed to get version", zap.String("remote-member-id", m.ID.String()), zap.Error(err))
+			} else {
+				plog.Warningf("cannot get the version of member %s (%v)", m.ID, err)
+			}
+			vers[m.ID.String()] = nil
+		} else {
+			vers[m.ID.String()] = ver
+		}
+	}
+	return vers
+}
+
+// decideClusterVersion decides the cluster version based on the versions map.
+// The returned version is the min server version in the map, or nil if the min
+// version in unknown.
+func decideClusterVersion(lg *zap.Logger, vers map[string]*version.Versions) *semver.Version {
+	var cv *semver.Version
+	lv := semver.Must(semver.NewVersion(version.Version))
+
+	for mid, ver := range vers {
+		if ver == nil {
+			return nil
+		}
+		v, err := semver.NewVersion(ver.Server)
+		if err != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to parse server version of remote member",
+					zap.String("remote-member-id", mid),
+					zap.String("remote-member-version", ver.Server),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("cannot understand the version of member %s (%v)", mid, err)
+			}
+			return nil
+		}
+		if lv.LessThan(*v) {
+			if lg != nil {
+				lg.Warn(
+					"leader found higher-versioned member",
+					zap.String("local-member-version", lv.String()),
+					zap.String("remote-member-id", mid),
+					zap.String("remote-member-version", ver.Server),
+				)
+			} else {
+				plog.Warningf("the local etcd version %s is not up-to-date", lv.String())
+				plog.Warningf("member %s has a higher version %s", mid, ver.Server)
+			}
+		}
+		if cv == nil {
+			cv = v
+		} else if v.LessThan(*cv) {
+			cv = v
+		}
+	}
+	return cv
+}
+
+// isCompatibleWithCluster return true if the local member has a compatible version with
+// the current running cluster.
+// The version is considered as compatible when at least one of the other members in the cluster has a
+// cluster version in the range of [MinClusterVersion, Version] and no known members has a cluster version
+// out of the range.
+// We set this rule since when the local member joins, another member might be offline.
+func isCompatibleWithCluster(lg *zap.Logger, cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) bool {
+	vers := getVersions(lg, cl, local, rt)
+	minV := semver.Must(semver.NewVersion(version.MinClusterVersion))
+	maxV := semver.Must(semver.NewVersion(version.Version))
+	maxV = &semver.Version{
+		Major: maxV.Major,
+		Minor: maxV.Minor,
+	}
+	return isCompatibleWithVers(lg, vers, local, minV, maxV)
+}
+
+func isCompatibleWithVers(lg *zap.Logger, vers map[string]*version.Versions, local types.ID, minV, maxV *semver.Version) bool {
+	var ok bool
+	for id, v := range vers {
+		// ignore comparison with local version
+		if id == local.String() {
+			continue
+		}
+		if v == nil {
+			continue
+		}
+		clusterv, err := semver.NewVersion(v.Cluster)
+		if err != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to parse cluster version of remote member",
+					zap.String("remote-member-id", id),
+					zap.String("remote-member-cluster-version", v.Cluster),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("cannot understand the cluster version of member %s (%v)", id, err)
+			}
+			continue
+		}
+		if clusterv.LessThan(*minV) {
+			if lg != nil {
+				lg.Warn(
+					"cluster version of remote member is not compatible; too low",
+					zap.String("remote-member-id", id),
+					zap.String("remote-member-cluster-version", clusterv.String()),
+					zap.String("minimum-cluster-version-supported", minV.String()),
+				)
+			} else {
+				plog.Warningf("the running cluster version(%v) is lower than the minimal cluster version(%v) supported", clusterv.String(), minV.String())
+			}
+			return false
+		}
+		if maxV.LessThan(*clusterv) {
+			if lg != nil {
+				lg.Warn(
+					"cluster version of remote member is not compatible; too high",
+					zap.String("remote-member-id", id),
+					zap.String("remote-member-cluster-version", clusterv.String()),
+					zap.String("minimum-cluster-version-supported", minV.String()),
+				)
+			} else {
+				plog.Warningf("the running cluster version(%v) is higher than the maximum cluster version(%v) supported", clusterv.String(), maxV.String())
+			}
+			return false
+		}
+		ok = true
+	}
+	return ok
+}
+
+// getVersion returns the Versions of the given member via its
+// peerURLs. Returns the last error if it fails to get the version.
+func getVersion(lg *zap.Logger, m *membership.Member, rt http.RoundTripper) (*version.Versions, error) {
+	cc := &http.Client{
+		Transport: rt,
+	}
+	var (
+		err  error
+		resp *http.Response
+	)
+
+	for _, u := range m.PeerURLs {
+		addr := u + "/version"
+		resp, err = cc.Get(addr)
+		if err != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to reach the peer URL",
+					zap.String("address", addr),
+					zap.String("remote-member-id", m.ID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("failed to reach the peerURL(%s) of member %s (%v)", u, m.ID, err)
+			}
+			continue
+		}
+		var b []byte
+		b, err = ioutil.ReadAll(resp.Body)
+		resp.Body.Close()
+		if err != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to read body of response",
+					zap.String("address", addr),
+					zap.String("remote-member-id", m.ID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("failed to read out the response body from the peerURL(%s) of member %s (%v)", u, m.ID, err)
+			}
+			continue
+		}
+		var vers version.Versions
+		if err = json.Unmarshal(b, &vers); err != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to unmarshal response",
+					zap.String("address", addr),
+					zap.String("remote-member-id", m.ID.String()),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("failed to unmarshal the response body got from the peerURL(%s) of member %s (%v)", u, m.ID, err)
+			}
+			continue
+		}
+		return &vers, nil
+	}
+	return nil, err
+}
+
+func promoteMemberHTTP(ctx context.Context, url string, id uint64, peerRt http.RoundTripper) ([]*membership.Member, error) {
+	cc := &http.Client{Transport: peerRt}
+	// TODO: refactor member http handler code
+	// cannot import etcdhttp, so manually construct url
+	requestUrl := url + "/members/promote/" + fmt.Sprintf("%d", id)
+	req, err := http.NewRequest("POST", requestUrl, nil)
+	if err != nil {
+		return nil, err
+	}
+	req = req.WithContext(ctx)
+	resp, err := cc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	b, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if resp.StatusCode == http.StatusRequestTimeout {
+		return nil, ErrTimeout
+	}
+	if resp.StatusCode == http.StatusPreconditionFailed {
+		// both ErrMemberNotLearner and ErrLearnerNotReady have same http status code
+		if strings.Contains(string(b), ErrLearnerNotReady.Error()) {
+			return nil, ErrLearnerNotReady
+		}
+		if strings.Contains(string(b), membership.ErrMemberNotLearner.Error()) {
+			return nil, membership.ErrMemberNotLearner
+		}
+		return nil, fmt.Errorf("member promote: unknown error(%s)", string(b))
+	}
+	if resp.StatusCode == http.StatusNotFound {
+		return nil, membership.ErrIDNotFound
+	}
+
+	if resp.StatusCode != http.StatusOK { // all other types of errors
+		return nil, fmt.Errorf("member promote: unknown error(%s)", string(b))
+	}
+
+	var membs []*membership.Member
+	if err := json.Unmarshal(b, &membs); err != nil {
+		return nil, err
+	}
+	return membs, nil
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/config.go b/vendor/go.etcd.io/etcd/etcdserver/config.go
new file mode 100644
index 0000000..88cd721
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/config.go
@@ -0,0 +1,307 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/pkg/netutil"
+	"go.etcd.io/etcd/pkg/transport"
+	"go.etcd.io/etcd/pkg/types"
+
+	bolt "go.etcd.io/bbolt"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+// ServerConfig holds the configuration of etcd as taken from the command line or discovery.
+type ServerConfig struct {
+	Name           string
+	DiscoveryURL   string
+	DiscoveryProxy string
+	ClientURLs     types.URLs
+	PeerURLs       types.URLs
+	DataDir        string
+	// DedicatedWALDir config will make the etcd to write the WAL to the WALDir
+	// rather than the dataDir/member/wal.
+	DedicatedWALDir string
+
+	SnapshotCount uint64
+
+	// SnapshotCatchUpEntries is the number of entries for a slow follower
+	// to catch-up after compacting the raft storage entries.
+	// We expect the follower has a millisecond level latency with the leader.
+	// The max throughput is around 10K. Keep a 5K entries is enough for helping
+	// follower to catch up.
+	// WARNING: only change this for tests. Always use "DefaultSnapshotCatchUpEntries"
+	SnapshotCatchUpEntries uint64
+
+	MaxSnapFiles uint
+	MaxWALFiles  uint
+
+	// BackendBatchInterval is the maximum time before commit the backend transaction.
+	BackendBatchInterval time.Duration
+	// BackendBatchLimit is the maximum operations before commit the backend transaction.
+	BackendBatchLimit int
+
+	// BackendFreelistType is the type of the backend boltdb freelist.
+	BackendFreelistType bolt.FreelistType
+
+	InitialPeerURLsMap  types.URLsMap
+	InitialClusterToken string
+	NewCluster          bool
+	PeerTLSInfo         transport.TLSInfo
+
+	CORS map[string]struct{}
+
+	// HostWhitelist lists acceptable hostnames from client requests.
+	// If server is insecure (no TLS), server only accepts requests
+	// whose Host header value exists in this white list.
+	HostWhitelist map[string]struct{}
+
+	TickMs        uint
+	ElectionTicks int
+
+	// InitialElectionTickAdvance is true, then local member fast-forwards
+	// election ticks to speed up "initial" leader election trigger. This
+	// benefits the case of larger election ticks. For instance, cross
+	// datacenter deployment may require longer election timeout of 10-second.
+	// If true, local node does not need wait up to 10-second. Instead,
+	// forwards its election ticks to 8-second, and have only 2-second left
+	// before leader election.
+	//
+	// Major assumptions are that:
+	//  - cluster has no active leader thus advancing ticks enables faster
+	//    leader election, or
+	//  - cluster already has an established leader, and rejoining follower
+	//    is likely to receive heartbeats from the leader after tick advance
+	//    and before election timeout.
+	//
+	// However, when network from leader to rejoining follower is congested,
+	// and the follower does not receive leader heartbeat within left election
+	// ticks, disruptive election has to happen thus affecting cluster
+	// availabilities.
+	//
+	// Disabling this would slow down initial bootstrap process for cross
+	// datacenter deployments. Make your own tradeoffs by configuring
+	// --initial-election-tick-advance at the cost of slow initial bootstrap.
+	//
+	// If single-node, it advances ticks regardless.
+	//
+	// See https://github.com/etcd-io/etcd/issues/9333 for more detail.
+	InitialElectionTickAdvance bool
+
+	BootstrapTimeout time.Duration
+
+	AutoCompactionRetention time.Duration
+	AutoCompactionMode      string
+	CompactionBatchLimit    int
+	QuotaBackendBytes       int64
+	MaxTxnOps               uint
+
+	// MaxRequestBytes is the maximum request size to send over raft.
+	MaxRequestBytes uint
+
+	StrictReconfigCheck bool
+
+	// ClientCertAuthEnabled is true when cert has been signed by the client CA.
+	ClientCertAuthEnabled bool
+
+	AuthToken  string
+	BcryptCost uint
+
+	// InitialCorruptCheck is true to check data corruption on boot
+	// before serving any peer/client traffic.
+	InitialCorruptCheck bool
+	CorruptCheckTime    time.Duration
+
+	// PreVote is true to enable Raft Pre-Vote.
+	PreVote bool
+
+	// Logger logs server-side operations.
+	// If not nil, it disables "capnslog" and uses the given logger.
+	Logger *zap.Logger
+
+	// LoggerConfig is server logger configuration for Raft logger.
+	// Must be either: "LoggerConfig != nil" or "LoggerCore != nil && LoggerWriteSyncer != nil".
+	LoggerConfig *zap.Config
+	// LoggerCore is "zapcore.Core" for raft logger.
+	// Must be either: "LoggerConfig != nil" or "LoggerCore != nil && LoggerWriteSyncer != nil".
+	LoggerCore        zapcore.Core
+	LoggerWriteSyncer zapcore.WriteSyncer
+
+	Debug bool
+
+	ForceNewCluster bool
+
+	// EnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
+	EnableLeaseCheckpoint bool
+	// LeaseCheckpointInterval time.Duration is the wait duration between lease checkpoints.
+	LeaseCheckpointInterval time.Duration
+
+	EnableGRPCGateway bool
+}
+
+// VerifyBootstrap sanity-checks the initial config for bootstrap case
+// and returns an error for things that should never happen.
+func (c *ServerConfig) VerifyBootstrap() error {
+	if err := c.hasLocalMember(); err != nil {
+		return err
+	}
+	if err := c.advertiseMatchesCluster(); err != nil {
+		return err
+	}
+	if checkDuplicateURL(c.InitialPeerURLsMap) {
+		return fmt.Errorf("initial cluster %s has duplicate url", c.InitialPeerURLsMap)
+	}
+	if c.InitialPeerURLsMap.String() == "" && c.DiscoveryURL == "" {
+		return fmt.Errorf("initial cluster unset and no discovery URL found")
+	}
+	return nil
+}
+
+// VerifyJoinExisting sanity-checks the initial config for join existing cluster
+// case and returns an error for things that should never happen.
+func (c *ServerConfig) VerifyJoinExisting() error {
+	// The member has announced its peer urls to the cluster before starting; no need to
+	// set the configuration again.
+	if err := c.hasLocalMember(); err != nil {
+		return err
+	}
+	if checkDuplicateURL(c.InitialPeerURLsMap) {
+		return fmt.Errorf("initial cluster %s has duplicate url", c.InitialPeerURLsMap)
+	}
+	if c.DiscoveryURL != "" {
+		return fmt.Errorf("discovery URL should not be set when joining existing initial cluster")
+	}
+	return nil
+}
+
+// hasLocalMember checks that the cluster at least contains the local server.
+func (c *ServerConfig) hasLocalMember() error {
+	if urls := c.InitialPeerURLsMap[c.Name]; urls == nil {
+		return fmt.Errorf("couldn't find local name %q in the initial cluster configuration", c.Name)
+	}
+	return nil
+}
+
+// advertiseMatchesCluster confirms peer URLs match those in the cluster peer list.
+func (c *ServerConfig) advertiseMatchesCluster() error {
+	urls, apurls := c.InitialPeerURLsMap[c.Name], c.PeerURLs.StringSlice()
+	urls.Sort()
+	sort.Strings(apurls)
+	ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
+	defer cancel()
+	ok, err := netutil.URLStringsEqual(ctx, c.Logger, apurls, urls.StringSlice())
+	if ok {
+		return nil
+	}
+
+	initMap, apMap := make(map[string]struct{}), make(map[string]struct{})
+	for _, url := range c.PeerURLs {
+		apMap[url.String()] = struct{}{}
+	}
+	for _, url := range c.InitialPeerURLsMap[c.Name] {
+		initMap[url.String()] = struct{}{}
+	}
+
+	missing := []string{}
+	for url := range initMap {
+		if _, ok := apMap[url]; !ok {
+			missing = append(missing, url)
+		}
+	}
+	if len(missing) > 0 {
+		for i := range missing {
+			missing[i] = c.Name + "=" + missing[i]
+		}
+		mstr := strings.Join(missing, ",")
+		apStr := strings.Join(apurls, ",")
+		return fmt.Errorf("--initial-cluster has %s but missing from --initial-advertise-peer-urls=%s (%v)", mstr, apStr, err)
+	}
+
+	for url := range apMap {
+		if _, ok := initMap[url]; !ok {
+			missing = append(missing, url)
+		}
+	}
+	if len(missing) > 0 {
+		mstr := strings.Join(missing, ",")
+		umap := types.URLsMap(map[string]types.URLs{c.Name: c.PeerURLs})
+		return fmt.Errorf("--initial-advertise-peer-urls has %s but missing from --initial-cluster=%s", mstr, umap.String())
+	}
+
+	// resolved URLs from "--initial-advertise-peer-urls" and "--initial-cluster" did not match or failed
+	apStr := strings.Join(apurls, ",")
+	umap := types.URLsMap(map[string]types.URLs{c.Name: c.PeerURLs})
+	return fmt.Errorf("failed to resolve %s to match --initial-cluster=%s (%v)", apStr, umap.String(), err)
+}
+
+func (c *ServerConfig) MemberDir() string { return filepath.Join(c.DataDir, "member") }
+
+func (c *ServerConfig) WALDir() string {
+	if c.DedicatedWALDir != "" {
+		return c.DedicatedWALDir
+	}
+	return filepath.Join(c.MemberDir(), "wal")
+}
+
+func (c *ServerConfig) SnapDir() string { return filepath.Join(c.MemberDir(), "snap") }
+
+func (c *ServerConfig) ShouldDiscover() bool { return c.DiscoveryURL != "" }
+
+// ReqTimeout returns timeout for request to finish.
+func (c *ServerConfig) ReqTimeout() time.Duration {
+	// 5s for queue waiting, computation and disk IO delay
+	// + 2 * election timeout for possible leader election
+	return 5*time.Second + 2*time.Duration(c.ElectionTicks*int(c.TickMs))*time.Millisecond
+}
+
+func (c *ServerConfig) electionTimeout() time.Duration {
+	return time.Duration(c.ElectionTicks*int(c.TickMs)) * time.Millisecond
+}
+
+func (c *ServerConfig) peerDialTimeout() time.Duration {
+	// 1s for queue wait and election timeout
+	return time.Second + time.Duration(c.ElectionTicks*int(c.TickMs))*time.Millisecond
+}
+
+func checkDuplicateURL(urlsmap types.URLsMap) bool {
+	um := make(map[string]bool)
+	for _, urls := range urlsmap {
+		for _, url := range urls {
+			u := url.String()
+			if um[u] {
+				return true
+			}
+			um[u] = true
+		}
+	}
+	return false
+}
+
+func (c *ServerConfig) bootstrapTimeout() time.Duration {
+	if c.BootstrapTimeout != 0 {
+		return c.BootstrapTimeout
+	}
+	return time.Second
+}
+
+func (c *ServerConfig) backendPath() string { return filepath.Join(c.SnapDir(), "db") }
diff --git a/vendor/go.etcd.io/etcd/etcdserver/consistent_index.go b/vendor/go.etcd.io/etcd/etcdserver/consistent_index.go
new file mode 100644
index 0000000..d513f67
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/consistent_index.go
@@ -0,0 +1,33 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"sync/atomic"
+)
+
+// consistentIndex represents the offset of an entry in a consistent replica log.
+// It implements the mvcc.ConsistentIndexGetter interface.
+// It is always set to the offset of current entry before executing the entry,
+// so ConsistentWatchableKV could get the consistent index from it.
+type consistentIndex uint64
+
+func (i *consistentIndex) setConsistentIndex(v uint64) {
+	atomic.StoreUint64((*uint64)(i), v)
+}
+
+func (i *consistentIndex) ConsistentIndex() uint64 {
+	return atomic.LoadUint64((*uint64)(i))
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/corrupt.go b/vendor/go.etcd.io/etcd/etcdserver/corrupt.go
new file mode 100644
index 0000000..32678a7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/corrupt.go
@@ -0,0 +1,411 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.etcd.io/etcd/clientv3"
+	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/pkg/types"
+
+	"go.uber.org/zap"
+)
+
+// CheckInitialHashKV compares initial hash values with its peers
+// before serving any peer/client traffic. Only mismatch when hashes
+// are different at requested revision, with same compact revision.
+func (s *EtcdServer) CheckInitialHashKV() error {
+	if !s.Cfg.InitialCorruptCheck {
+		return nil
+	}
+
+	lg := s.getLogger()
+
+	if lg != nil {
+		lg.Info(
+			"starting initial corruption check",
+			zap.String("local-member-id", s.ID().String()),
+			zap.Duration("timeout", s.Cfg.ReqTimeout()),
+		)
+	} else {
+		plog.Infof("%s starting initial corruption check with timeout %v...", s.ID(), s.Cfg.ReqTimeout())
+	}
+
+	h, rev, crev, err := s.kv.HashByRev(0)
+	if err != nil {
+		return fmt.Errorf("%s failed to fetch hash (%v)", s.ID(), err)
+	}
+	peers := s.getPeerHashKVs(rev)
+	mismatch := 0
+	for _, p := range peers {
+		if p.resp != nil {
+			peerID := types.ID(p.resp.Header.MemberId)
+			fields := []zap.Field{
+				zap.String("local-member-id", s.ID().String()),
+				zap.Int64("local-member-revision", rev),
+				zap.Int64("local-member-compact-revision", crev),
+				zap.Uint32("local-member-hash", h),
+				zap.String("remote-peer-id", peerID.String()),
+				zap.Strings("remote-peer-endpoints", p.eps),
+				zap.Int64("remote-peer-revision", p.resp.Header.Revision),
+				zap.Int64("remote-peer-compact-revision", p.resp.CompactRevision),
+				zap.Uint32("remote-peer-hash", p.resp.Hash),
+			}
+
+			if h != p.resp.Hash {
+				if crev == p.resp.CompactRevision {
+					if lg != nil {
+						lg.Warn("found different hash values from remote peer", fields...)
+					} else {
+						plog.Errorf("%s's hash %d != %s's hash %d (revision %d, peer revision %d, compact revision %d)", s.ID(), h, peerID, p.resp.Hash, rev, p.resp.Header.Revision, crev)
+					}
+					mismatch++
+				} else {
+					if lg != nil {
+						lg.Warn("found different compact revision values from remote peer", fields...)
+					} else {
+						plog.Warningf("%s cannot check hash of peer(%s): peer has a different compact revision %d (revision:%d)", s.ID(), peerID, p.resp.CompactRevision, rev)
+					}
+				}
+			}
+
+			continue
+		}
+
+		if p.err != nil {
+			switch p.err {
+			case rpctypes.ErrFutureRev:
+				if lg != nil {
+					lg.Warn(
+						"cannot fetch hash from slow remote peer",
+						zap.String("local-member-id", s.ID().String()),
+						zap.Int64("local-member-revision", rev),
+						zap.Int64("local-member-compact-revision", crev),
+						zap.Uint32("local-member-hash", h),
+						zap.String("remote-peer-id", p.id.String()),
+						zap.Strings("remote-peer-endpoints", p.eps),
+						zap.Error(err),
+					)
+				} else {
+					plog.Warningf("%s cannot check the hash of peer(%q) at revision %d: peer is lagging behind(%q)", s.ID(), p.eps, rev, p.err.Error())
+				}
+			case rpctypes.ErrCompacted:
+				if lg != nil {
+					lg.Warn(
+						"cannot fetch hash from remote peer; local member is behind",
+						zap.String("local-member-id", s.ID().String()),
+						zap.Int64("local-member-revision", rev),
+						zap.Int64("local-member-compact-revision", crev),
+						zap.Uint32("local-member-hash", h),
+						zap.String("remote-peer-id", p.id.String()),
+						zap.Strings("remote-peer-endpoints", p.eps),
+						zap.Error(err),
+					)
+				} else {
+					plog.Warningf("%s cannot check the hash of peer(%q) at revision %d: local node is lagging behind(%q)", s.ID(), p.eps, rev, p.err.Error())
+				}
+			}
+		}
+	}
+	if mismatch > 0 {
+		return fmt.Errorf("%s found data inconsistency with peers", s.ID())
+	}
+
+	if lg != nil {
+		lg.Info(
+			"initial corruption checking passed; no corruption",
+			zap.String("local-member-id", s.ID().String()),
+		)
+	} else {
+		plog.Infof("%s succeeded on initial corruption checking: no corruption", s.ID())
+	}
+	return nil
+}
+
+func (s *EtcdServer) monitorKVHash() {
+	t := s.Cfg.CorruptCheckTime
+	if t == 0 {
+		return
+	}
+
+	lg := s.getLogger()
+	if lg != nil {
+		lg.Info(
+			"enabled corruption checking",
+			zap.String("local-member-id", s.ID().String()),
+			zap.Duration("interval", t),
+		)
+	} else {
+		plog.Infof("enabled corruption checking with %s interval", t)
+	}
+
+	for {
+		select {
+		case <-s.stopping:
+			return
+		case <-time.After(t):
+		}
+		if !s.isLeader() {
+			continue
+		}
+		if err := s.checkHashKV(); err != nil {
+			if lg != nil {
+				lg.Warn("failed to check hash KV", zap.Error(err))
+			} else {
+				plog.Debugf("check hash kv failed %v", err)
+			}
+		}
+	}
+}
+
+func (s *EtcdServer) checkHashKV() error {
+	lg := s.getLogger()
+
+	h, rev, crev, err := s.kv.HashByRev(0)
+	if err != nil {
+		return err
+	}
+	peers := s.getPeerHashKVs(rev)
+
+	ctx, cancel := context.WithTimeout(context.Background(), s.Cfg.ReqTimeout())
+	err = s.linearizableReadNotify(ctx)
+	cancel()
+	if err != nil {
+		return err
+	}
+
+	h2, rev2, crev2, err := s.kv.HashByRev(0)
+	if err != nil {
+		return err
+	}
+
+	alarmed := false
+	mismatch := func(id uint64) {
+		if alarmed {
+			return
+		}
+		alarmed = true
+		a := &pb.AlarmRequest{
+			MemberID: id,
+			Action:   pb.AlarmRequest_ACTIVATE,
+			Alarm:    pb.AlarmType_CORRUPT,
+		}
+		s.goAttach(func() {
+			s.raftRequest(s.ctx, pb.InternalRaftRequest{Alarm: a})
+		})
+	}
+
+	if h2 != h && rev2 == rev && crev == crev2 {
+		if lg != nil {
+			lg.Warn(
+				"found hash mismatch",
+				zap.Int64("revision-1", rev),
+				zap.Int64("compact-revision-1", crev),
+				zap.Uint32("hash-1", h),
+				zap.Int64("revision-2", rev2),
+				zap.Int64("compact-revision-2", crev2),
+				zap.Uint32("hash-2", h2),
+			)
+		} else {
+			plog.Warningf("mismatched hashes %d and %d for revision %d", h, h2, rev)
+		}
+		mismatch(uint64(s.ID()))
+	}
+
+	for _, p := range peers {
+		if p.resp == nil {
+			continue
+		}
+		id := p.resp.Header.MemberId
+
+		// leader expects follower's latest revision less than or equal to leader's
+		if p.resp.Header.Revision > rev2 {
+			if lg != nil {
+				lg.Warn(
+					"revision from follower must be less than or equal to leader's",
+					zap.Int64("leader-revision", rev2),
+					zap.Int64("follower-revision", p.resp.Header.Revision),
+					zap.String("follower-peer-id", types.ID(id).String()),
+				)
+			} else {
+				plog.Warningf(
+					"revision %d from member %v, expected at most %d",
+					p.resp.Header.Revision,
+					types.ID(id),
+					rev2)
+			}
+			mismatch(id)
+		}
+
+		// leader expects follower's latest compact revision less than or equal to leader's
+		if p.resp.CompactRevision > crev2 {
+			if lg != nil {
+				lg.Warn(
+					"compact revision from follower must be less than or equal to leader's",
+					zap.Int64("leader-compact-revision", crev2),
+					zap.Int64("follower-compact-revision", p.resp.CompactRevision),
+					zap.String("follower-peer-id", types.ID(id).String()),
+				)
+			} else {
+				plog.Warningf(
+					"compact revision %d from member %v, expected at most %d",
+					p.resp.CompactRevision,
+					types.ID(id),
+					crev2,
+				)
+			}
+			mismatch(id)
+		}
+
+		// follower's compact revision is leader's old one, then hashes must match
+		if p.resp.CompactRevision == crev && p.resp.Hash != h {
+			if lg != nil {
+				lg.Warn(
+					"same compact revision then hashes must match",
+					zap.Int64("leader-compact-revision", crev2),
+					zap.Uint32("leader-hash", h),
+					zap.Int64("follower-compact-revision", p.resp.CompactRevision),
+					zap.Uint32("follower-hash", p.resp.Hash),
+					zap.String("follower-peer-id", types.ID(id).String()),
+				)
+			} else {
+				plog.Warningf(
+					"hash %d at revision %d from member %v, expected hash %d",
+					p.resp.Hash,
+					rev,
+					types.ID(id),
+					h,
+				)
+			}
+			mismatch(id)
+		}
+	}
+	return nil
+}
+
+type peerHashKVResp struct {
+	id  types.ID
+	eps []string
+
+	resp *clientv3.HashKVResponse
+	err  error
+}
+
+func (s *EtcdServer) getPeerHashKVs(rev int64) (resps []*peerHashKVResp) {
+	// TODO: handle the case when "s.cluster.Members" have not
+	// been populated (e.g. no snapshot to load from disk)
+	mbs := s.cluster.Members()
+	pss := make([]peerHashKVResp, len(mbs))
+	for _, m := range mbs {
+		if m.ID == s.ID() {
+			continue
+		}
+		pss = append(pss, peerHashKVResp{id: m.ID, eps: m.PeerURLs})
+	}
+
+	lg := s.getLogger()
+
+	for _, p := range pss {
+		if len(p.eps) == 0 {
+			continue
+		}
+		cli, cerr := clientv3.New(clientv3.Config{
+			DialTimeout: s.Cfg.ReqTimeout(),
+			Endpoints:   p.eps,
+		})
+		if cerr != nil {
+			if lg != nil {
+				lg.Warn(
+					"failed to create client to peer URL",
+					zap.String("local-member-id", s.ID().String()),
+					zap.String("remote-peer-id", p.id.String()),
+					zap.Strings("remote-peer-endpoints", p.eps),
+					zap.Error(cerr),
+				)
+			} else {
+				plog.Warningf("%s failed to create client to peer %q for hash checking (%q)", s.ID(), p.eps, cerr.Error())
+			}
+			continue
+		}
+
+		respsLen := len(resps)
+		for _, c := range cli.Endpoints() {
+			ctx, cancel := context.WithTimeout(context.Background(), s.Cfg.ReqTimeout())
+			var resp *clientv3.HashKVResponse
+			resp, cerr = cli.HashKV(ctx, c, rev)
+			cancel()
+			if cerr == nil {
+				resps = append(resps, &peerHashKVResp{id: p.id, eps: p.eps, resp: resp, err: nil})
+				break
+			}
+			if lg != nil {
+				lg.Warn(
+					"failed hash kv request",
+					zap.String("local-member-id", s.ID().String()),
+					zap.Int64("requested-revision", rev),
+					zap.String("remote-peer-endpoint", c),
+					zap.Error(cerr),
+				)
+			} else {
+				plog.Warningf("%s hash-kv error %q on peer %q with revision %d", s.ID(), cerr.Error(), c, rev)
+			}
+		}
+		cli.Close()
+
+		if respsLen == len(resps) {
+			resps = append(resps, &peerHashKVResp{id: p.id, eps: p.eps, resp: nil, err: cerr})
+		}
+	}
+	return resps
+}
+
+type applierV3Corrupt struct {
+	applierV3
+}
+
+func newApplierV3Corrupt(a applierV3) *applierV3Corrupt { return &applierV3Corrupt{a} }
+
+func (a *applierV3Corrupt) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error) {
+	return nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) Range(txn mvcc.TxnRead, p *pb.RangeRequest) (*pb.RangeResponse, error) {
+	return nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) DeleteRange(txn mvcc.TxnWrite, p *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	return nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	return nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) Compaction(compaction *pb.CompactionRequest) (*pb.CompactionResponse, <-chan struct{}, error) {
+	return nil, nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	return nil, ErrCorrupt
+}
+
+func (a *applierV3Corrupt) LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	return nil, ErrCorrupt
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/doc.go b/vendor/go.etcd.io/etcd/etcdserver/doc.go
new file mode 100644
index 0000000..b195d2d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package etcdserver defines how etcd servers interact and store their states.
+package etcdserver
diff --git a/vendor/go.etcd.io/etcd/etcdserver/errors.go b/vendor/go.etcd.io/etcd/etcdserver/errors.go
new file mode 100644
index 0000000..d0fe289
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/errors.go
@@ -0,0 +1,51 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	ErrUnknownMethod              = errors.New("etcdserver: unknown method")
+	ErrStopped                    = errors.New("etcdserver: server stopped")
+	ErrCanceled                   = errors.New("etcdserver: request cancelled")
+	ErrTimeout                    = errors.New("etcdserver: request timed out")
+	ErrTimeoutDueToLeaderFail     = errors.New("etcdserver: request timed out, possibly due to previous leader failure")
+	ErrTimeoutDueToConnectionLost = errors.New("etcdserver: request timed out, possibly due to connection lost")
+	ErrTimeoutLeaderTransfer      = errors.New("etcdserver: request timed out, leader transfer took too long")
+	ErrLeaderChanged              = errors.New("etcdserver: leader changed")
+	ErrNotEnoughStartedMembers    = errors.New("etcdserver: re-configuration failed due to not enough started members")
+	ErrLearnerNotReady            = errors.New("etcdserver: can only promote a learner member which is in sync with leader")
+	ErrNoLeader                   = errors.New("etcdserver: no leader")
+	ErrNotLeader                  = errors.New("etcdserver: not leader")
+	ErrRequestTooLarge            = errors.New("etcdserver: request is too large")
+	ErrNoSpace                    = errors.New("etcdserver: no space")
+	ErrTooManyRequests            = errors.New("etcdserver: too many requests")
+	ErrUnhealthy                  = errors.New("etcdserver: unhealthy cluster")
+	ErrKeyNotFound                = errors.New("etcdserver: key not found")
+	ErrCorrupt                    = errors.New("etcdserver: corrupt cluster")
+	ErrBadLeaderTransferee        = errors.New("etcdserver: bad leader transferee")
+)
+
+type DiscoveryError struct {
+	Op  string
+	Err error
+}
+
+func (e DiscoveryError) Error() string {
+	return fmt.Sprintf("failed to %s discovery cluster (%v)", e.Op, e.Err)
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/etcdserverpb/gw/rpc.pb.gw.go b/vendor/go.etcd.io/etcd/etcdserver/etcdserverpb/gw/rpc.pb.gw.go
new file mode 100644
index 0000000..904c321
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/etcdserverpb/gw/rpc.pb.gw.go
@@ -0,0 +1,2318 @@
+// Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
+// source: etcdserver/etcdserverpb/rpc.proto
+
+/*
+Package etcdserverpb is a reverse proxy.
+
+It translates gRPC into RESTful JSON APIs.
+*/
+package gw
+
+import (
+	"go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+var _ codes.Code
+var _ io.Reader
+var _ status.Status
+var _ = runtime.String
+var _ = utilities.NewDoubleArray
+
+func request_KV_Range_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.KVClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.RangeRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Range(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_KV_Put_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.KVClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.PutRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Put(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_KV_DeleteRange_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.KVClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.DeleteRangeRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.DeleteRange(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_KV_Txn_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.KVClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.TxnRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Txn(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_KV_Compact_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.KVClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.CompactionRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Compact(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Watch_Watch_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.WatchClient, req *http.Request, pathParams map[string]string) (etcdserverpb.Watch_WatchClient, runtime.ServerMetadata, error) {
+	var metadata runtime.ServerMetadata
+	stream, err := client.Watch(ctx)
+	if err != nil {
+		grpclog.Printf("Failed to start streaming: %v", err)
+		return nil, metadata, err
+	}
+	dec := marshaler.NewDecoder(req.Body)
+	handleSend := func() error {
+		var protoReq etcdserverpb.WatchRequest
+		err := dec.Decode(&protoReq)
+		if err == io.EOF {
+			return err
+		}
+		if err != nil {
+			grpclog.Printf("Failed to decode request: %v", err)
+			return err
+		}
+		if err := stream.Send(&protoReq); err != nil {
+			grpclog.Printf("Failed to send request: %v", err)
+			return err
+		}
+		return nil
+	}
+	if err := handleSend(); err != nil {
+		if cerr := stream.CloseSend(); cerr != nil {
+			grpclog.Printf("Failed to terminate client stream: %v", cerr)
+		}
+		if err == io.EOF {
+			return stream, metadata, nil
+		}
+		return nil, metadata, err
+	}
+	go func() {
+		for {
+			if err := handleSend(); err != nil {
+				break
+			}
+		}
+		if err := stream.CloseSend(); err != nil {
+			grpclog.Printf("Failed to terminate client stream: %v", err)
+		}
+	}()
+	header, err := stream.Header()
+	if err != nil {
+		grpclog.Printf("Failed to get header from client: %v", err)
+		return nil, metadata, err
+	}
+	metadata.HeaderMD = header
+	return stream, metadata, nil
+}
+
+func request_Lease_LeaseGrant_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseGrantRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseGrant(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseRevoke_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseRevokeRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseRevoke(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseRevoke_1(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseRevokeRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseRevoke(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseKeepAlive_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (etcdserverpb.Lease_LeaseKeepAliveClient, runtime.ServerMetadata, error) {
+	var metadata runtime.ServerMetadata
+	stream, err := client.LeaseKeepAlive(ctx)
+	if err != nil {
+		grpclog.Printf("Failed to start streaming: %v", err)
+		return nil, metadata, err
+	}
+	dec := marshaler.NewDecoder(req.Body)
+	handleSend := func() error {
+		var protoReq etcdserverpb.LeaseKeepAliveRequest
+		err := dec.Decode(&protoReq)
+		if err == io.EOF {
+			return err
+		}
+		if err != nil {
+			grpclog.Printf("Failed to decode request: %v", err)
+			return err
+		}
+		if err := stream.Send(&protoReq); err != nil {
+			grpclog.Printf("Failed to send request: %v", err)
+			return err
+		}
+		return nil
+	}
+	if err := handleSend(); err != nil {
+		if cerr := stream.CloseSend(); cerr != nil {
+			grpclog.Printf("Failed to terminate client stream: %v", cerr)
+		}
+		if err == io.EOF {
+			return stream, metadata, nil
+		}
+		return nil, metadata, err
+	}
+	go func() {
+		for {
+			if err := handleSend(); err != nil {
+				break
+			}
+		}
+		if err := stream.CloseSend(); err != nil {
+			grpclog.Printf("Failed to terminate client stream: %v", err)
+		}
+	}()
+	header, err := stream.Header()
+	if err != nil {
+		grpclog.Printf("Failed to get header from client: %v", err)
+		return nil, metadata, err
+	}
+	metadata.HeaderMD = header
+	return stream, metadata, nil
+}
+
+func request_Lease_LeaseTimeToLive_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseTimeToLiveRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseTimeToLive(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseTimeToLive_1(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseTimeToLiveRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseTimeToLive(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseLeases_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseLeasesRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseLeases(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Lease_LeaseLeases_1(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.LeaseClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.LeaseLeasesRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.LeaseLeases(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Cluster_MemberAdd_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.ClusterClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MemberAddRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MemberAdd(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Cluster_MemberRemove_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.ClusterClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MemberRemoveRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MemberRemove(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Cluster_MemberUpdate_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.ClusterClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MemberUpdateRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MemberUpdate(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Cluster_MemberList_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.ClusterClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MemberListRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MemberList(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Cluster_MemberPromote_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.ClusterClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MemberPromoteRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MemberPromote(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_Alarm_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AlarmRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Alarm(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_Status_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.StatusRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Status(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_Defragment_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.DefragmentRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Defragment(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_Hash_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.HashRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Hash(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_HashKV_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.HashKVRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.HashKV(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Maintenance_Snapshot_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (etcdserverpb.Maintenance_SnapshotClient, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.SnapshotRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	stream, err := client.Snapshot(ctx, &protoReq)
+	if err != nil {
+		return nil, metadata, err
+	}
+	header, err := stream.Header()
+	if err != nil {
+		return nil, metadata, err
+	}
+	metadata.HeaderMD = header
+	return stream, metadata, nil
+
+}
+
+func request_Maintenance_MoveLeader_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.MaintenanceClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.MoveLeaderRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.MoveLeader(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_AuthEnable_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthEnableRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.AuthEnable(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_AuthDisable_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthDisableRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.AuthDisable(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_Authenticate_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthenticateRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.Authenticate(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserAdd_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserAddRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserAdd(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserGet_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserGetRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserGet(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserList_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserListRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserList(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserDelete_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserDeleteRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserDelete(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserChangePassword_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserChangePasswordRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserChangePassword(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserGrantRole_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserGrantRoleRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserGrantRole(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_UserRevokeRole_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthUserRevokeRoleRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.UserRevokeRole(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleAdd_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleAddRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleAdd(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleGet_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleGetRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleGet(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleList_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleListRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleList(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleDelete_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleDeleteRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleDelete(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleGrantPermission_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleGrantPermissionRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleGrantPermission(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func request_Auth_RoleRevokePermission_0(ctx context.Context, marshaler runtime.Marshaler, client etcdserverpb.AuthClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq etcdserverpb.AuthRoleRevokePermissionRequest
+	var metadata runtime.ServerMetadata
+
+	if err := marshaler.NewDecoder(req.Body).Decode(&protoReq); err != nil && err != io.EOF {
+		return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
+	}
+
+	msg, err := client.RoleRevokePermission(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+// RegisterKVHandlerFromEndpoint is same as RegisterKVHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterKVHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterKVHandler(ctx, mux, conn)
+}
+
+// RegisterKVHandler registers the http handlers for service KV to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterKVHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterKVHandlerClient(ctx, mux, etcdserverpb.NewKVClient(conn))
+}
+
+// RegisterKVHandler registers the http handlers for service KV to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "KVClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "KVClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "KVClient" to call the correct interceptors.
+func RegisterKVHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.KVClient) error {
+
+	mux.Handle("POST", pattern_KV_Range_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_KV_Range_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_KV_Range_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_KV_Put_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_KV_Put_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_KV_Put_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_KV_DeleteRange_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_KV_DeleteRange_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_KV_DeleteRange_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_KV_Txn_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_KV_Txn_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_KV_Txn_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_KV_Compact_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_KV_Compact_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_KV_Compact_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_KV_Range_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "kv", "range"}, ""))
+
+	pattern_KV_Put_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "kv", "put"}, ""))
+
+	pattern_KV_DeleteRange_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "kv", "deleterange"}, ""))
+
+	pattern_KV_Txn_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "kv", "txn"}, ""))
+
+	pattern_KV_Compact_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "kv", "compaction"}, ""))
+)
+
+var (
+	forward_KV_Range_0 = runtime.ForwardResponseMessage
+
+	forward_KV_Put_0 = runtime.ForwardResponseMessage
+
+	forward_KV_DeleteRange_0 = runtime.ForwardResponseMessage
+
+	forward_KV_Txn_0 = runtime.ForwardResponseMessage
+
+	forward_KV_Compact_0 = runtime.ForwardResponseMessage
+)
+
+// RegisterWatchHandlerFromEndpoint is same as RegisterWatchHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterWatchHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterWatchHandler(ctx, mux, conn)
+}
+
+// RegisterWatchHandler registers the http handlers for service Watch to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterWatchHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterWatchHandlerClient(ctx, mux, etcdserverpb.NewWatchClient(conn))
+}
+
+// RegisterWatchHandler registers the http handlers for service Watch to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "WatchClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "WatchClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "WatchClient" to call the correct interceptors.
+func RegisterWatchHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.WatchClient) error {
+
+	mux.Handle("POST", pattern_Watch_Watch_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Watch_Watch_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Watch_Watch_0(ctx, mux, outboundMarshaler, w, req, func() (proto.Message, error) { return resp.Recv() }, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Watch_Watch_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1}, []string{"v3", "watch"}, ""))
+)
+
+var (
+	forward_Watch_Watch_0 = runtime.ForwardResponseStream
+)
+
+// RegisterLeaseHandlerFromEndpoint is same as RegisterLeaseHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterLeaseHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterLeaseHandler(ctx, mux, conn)
+}
+
+// RegisterLeaseHandler registers the http handlers for service Lease to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterLeaseHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterLeaseHandlerClient(ctx, mux, etcdserverpb.NewLeaseClient(conn))
+}
+
+// RegisterLeaseHandler registers the http handlers for service Lease to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "LeaseClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "LeaseClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "LeaseClient" to call the correct interceptors.
+func RegisterLeaseHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.LeaseClient) error {
+
+	mux.Handle("POST", pattern_Lease_LeaseGrant_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseGrant_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseGrant_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseRevoke_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseRevoke_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseRevoke_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseRevoke_1, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseRevoke_1(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseRevoke_1(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseKeepAlive_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseKeepAlive_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseKeepAlive_0(ctx, mux, outboundMarshaler, w, req, func() (proto.Message, error) { return resp.Recv() }, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseTimeToLive_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseTimeToLive_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseTimeToLive_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseTimeToLive_1, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseTimeToLive_1(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseTimeToLive_1(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseLeases_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseLeases_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseLeases_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Lease_LeaseLeases_1, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Lease_LeaseLeases_1(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Lease_LeaseLeases_1(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Lease_LeaseGrant_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lease", "grant"}, ""))
+
+	pattern_Lease_LeaseRevoke_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lease", "revoke"}, ""))
+
+	pattern_Lease_LeaseRevoke_1 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "kv", "lease", "revoke"}, ""))
+
+	pattern_Lease_LeaseKeepAlive_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lease", "keepalive"}, ""))
+
+	pattern_Lease_LeaseTimeToLive_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lease", "timetolive"}, ""))
+
+	pattern_Lease_LeaseTimeToLive_1 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "kv", "lease", "timetolive"}, ""))
+
+	pattern_Lease_LeaseLeases_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "lease", "leases"}, ""))
+
+	pattern_Lease_LeaseLeases_1 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "kv", "lease", "leases"}, ""))
+)
+
+var (
+	forward_Lease_LeaseGrant_0 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseRevoke_0 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseRevoke_1 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseKeepAlive_0 = runtime.ForwardResponseStream
+
+	forward_Lease_LeaseTimeToLive_0 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseTimeToLive_1 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseLeases_0 = runtime.ForwardResponseMessage
+
+	forward_Lease_LeaseLeases_1 = runtime.ForwardResponseMessage
+)
+
+// RegisterClusterHandlerFromEndpoint is same as RegisterClusterHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterClusterHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterClusterHandler(ctx, mux, conn)
+}
+
+// RegisterClusterHandler registers the http handlers for service Cluster to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterClusterHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterClusterHandlerClient(ctx, mux, etcdserverpb.NewClusterClient(conn))
+}
+
+// RegisterClusterHandler registers the http handlers for service Cluster to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "ClusterClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "ClusterClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "ClusterClient" to call the correct interceptors.
+func RegisterClusterHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.ClusterClient) error {
+
+	mux.Handle("POST", pattern_Cluster_MemberAdd_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Cluster_MemberAdd_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Cluster_MemberAdd_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Cluster_MemberRemove_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Cluster_MemberRemove_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Cluster_MemberRemove_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Cluster_MemberUpdate_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Cluster_MemberUpdate_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Cluster_MemberUpdate_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Cluster_MemberList_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Cluster_MemberList_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Cluster_MemberList_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Cluster_MemberPromote_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Cluster_MemberPromote_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Cluster_MemberPromote_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Cluster_MemberAdd_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "cluster", "member", "add"}, ""))
+
+	pattern_Cluster_MemberRemove_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "cluster", "member", "remove"}, ""))
+
+	pattern_Cluster_MemberUpdate_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "cluster", "member", "update"}, ""))
+
+	pattern_Cluster_MemberList_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "cluster", "member", "list"}, ""))
+
+	pattern_Cluster_MemberPromote_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "cluster", "member", "promote"}, ""))
+)
+
+var (
+	forward_Cluster_MemberAdd_0 = runtime.ForwardResponseMessage
+
+	forward_Cluster_MemberRemove_0 = runtime.ForwardResponseMessage
+
+	forward_Cluster_MemberUpdate_0 = runtime.ForwardResponseMessage
+
+	forward_Cluster_MemberList_0 = runtime.ForwardResponseMessage
+
+	forward_Cluster_MemberPromote_0 = runtime.ForwardResponseMessage
+)
+
+// RegisterMaintenanceHandlerFromEndpoint is same as RegisterMaintenanceHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterMaintenanceHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterMaintenanceHandler(ctx, mux, conn)
+}
+
+// RegisterMaintenanceHandler registers the http handlers for service Maintenance to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterMaintenanceHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterMaintenanceHandlerClient(ctx, mux, etcdserverpb.NewMaintenanceClient(conn))
+}
+
+// RegisterMaintenanceHandler registers the http handlers for service Maintenance to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "MaintenanceClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "MaintenanceClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "MaintenanceClient" to call the correct interceptors.
+func RegisterMaintenanceHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.MaintenanceClient) error {
+
+	mux.Handle("POST", pattern_Maintenance_Alarm_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_Alarm_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_Alarm_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_Status_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_Status_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_Status_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_Defragment_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_Defragment_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_Defragment_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_Hash_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_Hash_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_Hash_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_HashKV_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_HashKV_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_HashKV_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_Snapshot_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_Snapshot_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_Snapshot_0(ctx, mux, outboundMarshaler, w, req, func() (proto.Message, error) { return resp.Recv() }, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Maintenance_MoveLeader_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Maintenance_MoveLeader_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Maintenance_MoveLeader_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Maintenance_Alarm_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "alarm"}, ""))
+
+	pattern_Maintenance_Status_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "status"}, ""))
+
+	pattern_Maintenance_Defragment_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "defragment"}, ""))
+
+	pattern_Maintenance_Hash_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "hash"}, ""))
+
+	pattern_Maintenance_HashKV_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "hash"}, ""))
+
+	pattern_Maintenance_Snapshot_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "snapshot"}, ""))
+
+	pattern_Maintenance_MoveLeader_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "maintenance", "transfer-leadership"}, ""))
+)
+
+var (
+	forward_Maintenance_Alarm_0 = runtime.ForwardResponseMessage
+
+	forward_Maintenance_Status_0 = runtime.ForwardResponseMessage
+
+	forward_Maintenance_Defragment_0 = runtime.ForwardResponseMessage
+
+	forward_Maintenance_Hash_0 = runtime.ForwardResponseMessage
+
+	forward_Maintenance_HashKV_0 = runtime.ForwardResponseMessage
+
+	forward_Maintenance_Snapshot_0 = runtime.ForwardResponseStream
+
+	forward_Maintenance_MoveLeader_0 = runtime.ForwardResponseMessage
+)
+
+// RegisterAuthHandlerFromEndpoint is same as RegisterAuthHandler but
+// automatically dials to "endpoint" and closes the connection when "ctx" gets done.
+func RegisterAuthHandlerFromEndpoint(ctx context.Context, mux *runtime.ServeMux, endpoint string, opts []grpc.DialOption) (err error) {
+	conn, err := grpc.Dial(endpoint, opts...)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err != nil {
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+			return
+		}
+		go func() {
+			<-ctx.Done()
+			if cerr := conn.Close(); cerr != nil {
+				grpclog.Printf("Failed to close conn to %s: %v", endpoint, cerr)
+			}
+		}()
+	}()
+
+	return RegisterAuthHandler(ctx, mux, conn)
+}
+
+// RegisterAuthHandler registers the http handlers for service Auth to "mux".
+// The handlers forward requests to the grpc endpoint over "conn".
+func RegisterAuthHandler(ctx context.Context, mux *runtime.ServeMux, conn *grpc.ClientConn) error {
+	return RegisterAuthHandlerClient(ctx, mux, etcdserverpb.NewAuthClient(conn))
+}
+
+// RegisterAuthHandler registers the http handlers for service Auth to "mux".
+// The handlers forward requests to the grpc endpoint over the given implementation of "AuthClient".
+// Note: the gRPC framework executes interceptors within the gRPC handler. If the passed in "AuthClient"
+// doesn't go through the normal gRPC flow (creating a gRPC client etc.) then it will be up to the passed in
+// "AuthClient" to call the correct interceptors.
+func RegisterAuthHandlerClient(ctx context.Context, mux *runtime.ServeMux, client etcdserverpb.AuthClient) error {
+
+	mux.Handle("POST", pattern_Auth_AuthEnable_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_AuthEnable_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_AuthEnable_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_AuthDisable_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_AuthDisable_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_AuthDisable_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_Authenticate_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_Authenticate_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_Authenticate_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserAdd_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserAdd_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserAdd_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserGet_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserGet_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserGet_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserList_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserList_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserList_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserDelete_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserDelete_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserDelete_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserChangePassword_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserChangePassword_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserChangePassword_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserGrantRole_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserGrantRole_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserGrantRole_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_UserRevokeRole_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_UserRevokeRole_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_UserRevokeRole_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleAdd_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleAdd_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleAdd_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleGet_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleGet_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleGet_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleList_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleList_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleList_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleDelete_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleDelete_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleDelete_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleGrantPermission_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleGrantPermission_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleGrantPermission_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	mux.Handle("POST", pattern_Auth_RoleRevokePermission_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		if cn, ok := w.(http.CloseNotifier); ok {
+			go func(done <-chan struct{}, closed <-chan bool) {
+				select {
+				case <-done:
+				case <-closed:
+					cancel()
+				}
+			}(ctx.Done(), cn.CloseNotify())
+		}
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_Auth_RoleRevokePermission_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_Auth_RoleRevokePermission_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
+	return nil
+}
+
+var (
+	pattern_Auth_AuthEnable_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "auth", "enable"}, ""))
+
+	pattern_Auth_AuthDisable_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "auth", "disable"}, ""))
+
+	pattern_Auth_Authenticate_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v3", "auth", "authenticate"}, ""))
+
+	pattern_Auth_UserAdd_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "add"}, ""))
+
+	pattern_Auth_UserGet_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "get"}, ""))
+
+	pattern_Auth_UserList_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "list"}, ""))
+
+	pattern_Auth_UserDelete_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "delete"}, ""))
+
+	pattern_Auth_UserChangePassword_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "changepw"}, ""))
+
+	pattern_Auth_UserGrantRole_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "grant"}, ""))
+
+	pattern_Auth_UserRevokeRole_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "user", "revoke"}, ""))
+
+	pattern_Auth_RoleAdd_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "add"}, ""))
+
+	pattern_Auth_RoleGet_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "get"}, ""))
+
+	pattern_Auth_RoleList_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "list"}, ""))
+
+	pattern_Auth_RoleDelete_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "delete"}, ""))
+
+	pattern_Auth_RoleGrantPermission_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "grant"}, ""))
+
+	pattern_Auth_RoleRevokePermission_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2, 2, 3}, []string{"v3", "auth", "role", "revoke"}, ""))
+)
+
+var (
+	forward_Auth_AuthEnable_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_AuthDisable_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_Authenticate_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserAdd_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserGet_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserList_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserDelete_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserChangePassword_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserGrantRole_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_UserRevokeRole_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleAdd_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleGet_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleList_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleDelete_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleGrantPermission_0 = runtime.ForwardResponseMessage
+
+	forward_Auth_RoleRevokePermission_0 = runtime.ForwardResponseMessage
+)
diff --git a/vendor/go.etcd.io/etcd/etcdserver/metrics.go b/vendor/go.etcd.io/etcd/etcdserver/metrics.go
new file mode 100644
index 0000000..e0c0cde
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/metrics.go
@@ -0,0 +1,221 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	goruntime "runtime"
+	"time"
+
+	"go.etcd.io/etcd/pkg/runtime"
+	"go.etcd.io/etcd/version"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
+)
+
+var (
+	hasLeader = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "has_leader",
+		Help:      "Whether or not a leader exists. 1 is existence, 0 is not.",
+	})
+	isLeader = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "is_leader",
+		Help:      "Whether or not this member is a leader. 1 if is, 0 otherwise.",
+	})
+	leaderChanges = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "leader_changes_seen_total",
+		Help:      "The number of leader changes seen.",
+	})
+	isLearner = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "is_learner",
+		Help:      "Whether or not this member is a learner. 1 if is, 0 otherwise.",
+	})
+	learnerPromoteFailed = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "learner_promote_failures",
+		Help:      "The total number of failed learner promotions (likely learner not ready) while this member is leader.",
+	},
+		[]string{"Reason"},
+	)
+	learnerPromoteSucceed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "learner_promote_successes",
+		Help:      "The total number of successful learner promotions while this member is leader.",
+	})
+	heartbeatSendFailures = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "heartbeat_send_failures_total",
+		Help:      "The total number of leader heartbeat send failures (likely overloaded from slow disk).",
+	})
+	slowApplies = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "slow_apply_total",
+		Help:      "The total number of slow apply requests (likely overloaded from slow disk).",
+	})
+	applySnapshotInProgress = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "snapshot_apply_in_progress_total",
+		Help:      "1 if the server is applying the incoming snapshot. 0 if none.",
+	})
+	proposalsCommitted = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_committed_total",
+		Help:      "The total number of consensus proposals committed.",
+	})
+	proposalsApplied = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_applied_total",
+		Help:      "The total number of consensus proposals applied.",
+	})
+	proposalsPending = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_pending",
+		Help:      "The current number of pending proposals to commit.",
+	})
+	proposalsFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "proposals_failed_total",
+		Help:      "The total number of failed proposals seen.",
+	})
+	slowReadIndex = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "slow_read_indexes_total",
+		Help:      "The total number of pending read indexes not in sync with leader's or timed out read index requests.",
+	})
+	readIndexFailed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "read_indexes_failed_total",
+		Help:      "The total number of failed read indexes seen.",
+	})
+	leaseExpired = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "server",
+		Name:      "lease_expired_total",
+		Help:      "The total number of expired leases.",
+	})
+	quotaBackendBytes = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "quota_backend_bytes",
+		Help:      "Current backend storage quota size in bytes.",
+	})
+	currentVersion = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "version",
+		Help:      "Which version is running. 1 for 'server_version' label with current version.",
+	},
+		[]string{"server_version"})
+	currentGoVersion = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "go_version",
+		Help:      "Which Go version server is running with. 1 for 'server_go_version' label with current version.",
+	},
+		[]string{"server_go_version"})
+	serverID = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "id",
+		Help:      "Server or member ID in hexadecimal format. 1 for 'server_id' label with current ID.",
+	},
+		[]string{"server_id"})
+)
+
+func init() {
+	prometheus.MustRegister(hasLeader)
+	prometheus.MustRegister(isLeader)
+	prometheus.MustRegister(leaderChanges)
+	prometheus.MustRegister(heartbeatSendFailures)
+	prometheus.MustRegister(slowApplies)
+	prometheus.MustRegister(applySnapshotInProgress)
+	prometheus.MustRegister(proposalsCommitted)
+	prometheus.MustRegister(proposalsApplied)
+	prometheus.MustRegister(proposalsPending)
+	prometheus.MustRegister(proposalsFailed)
+	prometheus.MustRegister(slowReadIndex)
+	prometheus.MustRegister(readIndexFailed)
+	prometheus.MustRegister(leaseExpired)
+	prometheus.MustRegister(quotaBackendBytes)
+	prometheus.MustRegister(currentVersion)
+	prometheus.MustRegister(currentGoVersion)
+	prometheus.MustRegister(serverID)
+	prometheus.MustRegister(isLearner)
+	prometheus.MustRegister(learnerPromoteSucceed)
+	prometheus.MustRegister(learnerPromoteFailed)
+
+	currentVersion.With(prometheus.Labels{
+		"server_version": version.Version,
+	}).Set(1)
+	currentGoVersion.With(prometheus.Labels{
+		"server_go_version": goruntime.Version(),
+	}).Set(1)
+}
+
+func monitorFileDescriptor(lg *zap.Logger, done <-chan struct{}) {
+	ticker := time.NewTicker(5 * time.Second)
+	defer ticker.Stop()
+	for {
+		used, err := runtime.FDUsage()
+		if err != nil {
+			if lg != nil {
+				lg.Warn("failed to get file descriptor usage", zap.Error(err))
+			} else {
+				plog.Errorf("cannot monitor file descriptor usage (%v)", err)
+			}
+			return
+		}
+		limit, err := runtime.FDLimit()
+		if err != nil {
+			if lg != nil {
+				lg.Warn("failed to get file descriptor limit", zap.Error(err))
+			} else {
+				plog.Errorf("cannot monitor file descriptor usage (%v)", err)
+			}
+			return
+		}
+		if used >= limit/5*4 {
+			if lg != nil {
+				lg.Warn("80% of file descriptors are used", zap.Uint64("used", used), zap.Uint64("limit", limit))
+			} else {
+				plog.Warningf("80%% of the file descriptor limit is used [used = %d, limit = %d]", used, limit)
+			}
+		}
+		select {
+		case <-ticker.C:
+		case <-done:
+			return
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/quota.go b/vendor/go.etcd.io/etcd/etcdserver/quota.go
new file mode 100644
index 0000000..6d70430
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/quota.go
@@ -0,0 +1,182 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"sync"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	humanize "github.com/dustin/go-humanize"
+	"go.uber.org/zap"
+)
+
+const (
+	// DefaultQuotaBytes is the number of bytes the backend Size may
+	// consume before exceeding the space quota.
+	DefaultQuotaBytes = int64(2 * 1024 * 1024 * 1024) // 2GB
+	// MaxQuotaBytes is the maximum number of bytes suggested for a backend
+	// quota. A larger quota may lead to degraded performance.
+	MaxQuotaBytes = int64(8 * 1024 * 1024 * 1024) // 8GB
+)
+
+// Quota represents an arbitrary quota against arbitrary requests. Each request
+// costs some charge; if there is not enough remaining charge, then there are
+// too few resources available within the quota to apply the request.
+type Quota interface {
+	// Available judges whether the given request fits within the quota.
+	Available(req interface{}) bool
+	// Cost computes the charge against the quota for a given request.
+	Cost(req interface{}) int
+	// Remaining is the amount of charge left for the quota.
+	Remaining() int64
+}
+
+type passthroughQuota struct{}
+
+func (*passthroughQuota) Available(interface{}) bool { return true }
+func (*passthroughQuota) Cost(interface{}) int       { return 0 }
+func (*passthroughQuota) Remaining() int64           { return 1 }
+
+type backendQuota struct {
+	s               *EtcdServer
+	maxBackendBytes int64
+}
+
+const (
+	// leaseOverhead is an estimate for the cost of storing a lease
+	leaseOverhead = 64
+	// kvOverhead is an estimate for the cost of storing a key's metadata
+	kvOverhead = 256
+)
+
+var (
+	// only log once
+	quotaLogOnce sync.Once
+
+	DefaultQuotaSize = humanize.Bytes(uint64(DefaultQuotaBytes))
+	maxQuotaSize     = humanize.Bytes(uint64(MaxQuotaBytes))
+)
+
+// NewBackendQuota creates a quota layer with the given storage limit.
+func NewBackendQuota(s *EtcdServer, name string) Quota {
+	lg := s.getLogger()
+	quotaBackendBytes.Set(float64(s.Cfg.QuotaBackendBytes))
+
+	if s.Cfg.QuotaBackendBytes < 0 {
+		// disable quotas if negative
+		quotaLogOnce.Do(func() {
+			if lg != nil {
+				lg.Info(
+					"disabled backend quota",
+					zap.String("quota-name", name),
+					zap.Int64("quota-size-bytes", s.Cfg.QuotaBackendBytes),
+				)
+			} else {
+				plog.Warningf("disabling backend quota")
+			}
+		})
+		return &passthroughQuota{}
+	}
+
+	if s.Cfg.QuotaBackendBytes == 0 {
+		// use default size if no quota size given
+		quotaLogOnce.Do(func() {
+			if lg != nil {
+				lg.Info(
+					"enabled backend quota with default value",
+					zap.String("quota-name", name),
+					zap.Int64("quota-size-bytes", DefaultQuotaBytes),
+					zap.String("quota-size", DefaultQuotaSize),
+				)
+			}
+		})
+		quotaBackendBytes.Set(float64(DefaultQuotaBytes))
+		return &backendQuota{s, DefaultQuotaBytes}
+	}
+
+	quotaLogOnce.Do(func() {
+		if s.Cfg.QuotaBackendBytes > MaxQuotaBytes {
+			if lg != nil {
+				lg.Warn(
+					"quota exceeds the maximum value",
+					zap.String("quota-name", name),
+					zap.Int64("quota-size-bytes", s.Cfg.QuotaBackendBytes),
+					zap.String("quota-size", humanize.Bytes(uint64(s.Cfg.QuotaBackendBytes))),
+					zap.Int64("quota-maximum-size-bytes", MaxQuotaBytes),
+					zap.String("quota-maximum-size", maxQuotaSize),
+				)
+			} else {
+				plog.Warningf("backend quota %v exceeds maximum recommended quota %v", s.Cfg.QuotaBackendBytes, MaxQuotaBytes)
+			}
+		}
+		if lg != nil {
+			lg.Info(
+				"enabled backend quota",
+				zap.String("quota-name", name),
+				zap.Int64("quota-size-bytes", s.Cfg.QuotaBackendBytes),
+				zap.String("quota-size", humanize.Bytes(uint64(s.Cfg.QuotaBackendBytes))),
+			)
+		}
+	})
+	return &backendQuota{s, s.Cfg.QuotaBackendBytes}
+}
+
+func (b *backendQuota) Available(v interface{}) bool {
+	// TODO: maybe optimize backend.Size()
+	return b.s.Backend().Size()+int64(b.Cost(v)) < b.maxBackendBytes
+}
+
+func (b *backendQuota) Cost(v interface{}) int {
+	switch r := v.(type) {
+	case *pb.PutRequest:
+		return costPut(r)
+	case *pb.TxnRequest:
+		return costTxn(r)
+	case *pb.LeaseGrantRequest:
+		return leaseOverhead
+	default:
+		panic("unexpected cost")
+	}
+}
+
+func costPut(r *pb.PutRequest) int { return kvOverhead + len(r.Key) + len(r.Value) }
+
+func costTxnReq(u *pb.RequestOp) int {
+	r := u.GetRequestPut()
+	if r == nil {
+		return 0
+	}
+	return costPut(r)
+}
+
+func costTxn(r *pb.TxnRequest) int {
+	sizeSuccess := 0
+	for _, u := range r.Success {
+		sizeSuccess += costTxnReq(u)
+	}
+	sizeFailure := 0
+	for _, u := range r.Failure {
+		sizeFailure += costTxnReq(u)
+	}
+	if sizeFailure > sizeSuccess {
+		return sizeFailure
+	}
+	return sizeSuccess
+}
+
+func (b *backendQuota) Remaining() int64 {
+	return b.maxBackendBytes - b.s.Backend().Size()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/raft.go b/vendor/go.etcd.io/etcd/etcdserver/raft.go
new file mode 100644
index 0000000..c0fe979
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/raft.go
@@ -0,0 +1,753 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"encoding/json"
+	"expvar"
+	"fmt"
+	"log"
+	"sort"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/contention"
+	"go.etcd.io/etcd/pkg/logutil"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/wal"
+	"go.etcd.io/etcd/wal/walpb"
+	"go.uber.org/zap"
+)
+
+const (
+	// The max throughput of etcd will not exceed 100MB/s (100K * 1KB value).
+	// Assuming the RTT is around 10ms, 1MB max size is large enough.
+	maxSizePerMsg = 1 * 1024 * 1024
+	// Never overflow the rafthttp buffer, which is 4096.
+	// TODO: a better const?
+	maxInflightMsgs = 4096 / 8
+)
+
+var (
+	// protects raftStatus
+	raftStatusMu sync.Mutex
+	// indirection for expvar func interface
+	// expvar panics when publishing duplicate name
+	// expvar does not support remove a registered name
+	// so only register a func that calls raftStatus
+	// and change raftStatus as we need.
+	raftStatus func() raft.Status
+)
+
+func init() {
+	expvar.Publish("raft.status", expvar.Func(func() interface{} {
+		raftStatusMu.Lock()
+		defer raftStatusMu.Unlock()
+		return raftStatus()
+	}))
+}
+
+// apply contains entries, snapshot to be applied. Once
+// an apply is consumed, the entries will be persisted to
+// to raft storage concurrently; the application must read
+// raftDone before assuming the raft messages are stable.
+type apply struct {
+	entries  []raftpb.Entry
+	snapshot raftpb.Snapshot
+	// notifyc synchronizes etcd server applies with the raft node
+	notifyc chan struct{}
+}
+
+type raftNode struct {
+	lg *zap.Logger
+
+	tickMu *sync.Mutex
+	raftNodeConfig
+
+	// a chan to send/receive snapshot
+	msgSnapC chan raftpb.Message
+
+	// a chan to send out apply
+	applyc chan apply
+
+	// a chan to send out readState
+	readStateC chan raft.ReadState
+
+	// utility
+	ticker *time.Ticker
+	// contention detectors for raft heartbeat message
+	td *contention.TimeoutDetector
+
+	stopped chan struct{}
+	done    chan struct{}
+}
+
+type raftNodeConfig struct {
+	lg *zap.Logger
+
+	// to check if msg receiver is removed from cluster
+	isIDRemoved func(id uint64) bool
+	raft.Node
+	raftStorage *raft.MemoryStorage
+	storage     Storage
+	heartbeat   time.Duration // for logging
+	// transport specifies the transport to send and receive msgs to members.
+	// Sending messages MUST NOT block. It is okay to drop messages, since
+	// clients should timeout and reissue their messages.
+	// If transport is nil, server will panic.
+	transport rafthttp.Transporter
+}
+
+func newRaftNode(cfg raftNodeConfig) *raftNode {
+	var lg raft.Logger
+	if cfg.lg != nil {
+		lg = logutil.NewRaftLoggerZap(cfg.lg)
+	} else {
+		lcfg := logutil.DefaultZapLoggerConfig
+		var err error
+		lg, err = logutil.NewRaftLogger(&lcfg)
+		if err != nil {
+			log.Fatalf("cannot create raft logger %v", err)
+		}
+	}
+	raft.SetLogger(lg)
+	r := &raftNode{
+		lg:             cfg.lg,
+		tickMu:         new(sync.Mutex),
+		raftNodeConfig: cfg,
+		// set up contention detectors for raft heartbeat message.
+		// expect to send a heartbeat within 2 heartbeat intervals.
+		td:         contention.NewTimeoutDetector(2 * cfg.heartbeat),
+		readStateC: make(chan raft.ReadState, 1),
+		msgSnapC:   make(chan raftpb.Message, maxInFlightMsgSnap),
+		applyc:     make(chan apply),
+		stopped:    make(chan struct{}),
+		done:       make(chan struct{}),
+	}
+	if r.heartbeat == 0 {
+		r.ticker = &time.Ticker{}
+	} else {
+		r.ticker = time.NewTicker(r.heartbeat)
+	}
+	return r
+}
+
+// raft.Node does not have locks in Raft package
+func (r *raftNode) tick() {
+	r.tickMu.Lock()
+	r.Tick()
+	r.tickMu.Unlock()
+}
+
+// start prepares and starts raftNode in a new goroutine. It is no longer safe
+// to modify the fields after it has been started.
+func (r *raftNode) start(rh *raftReadyHandler) {
+	internalTimeout := time.Second
+
+	go func() {
+		defer r.onStop()
+		islead := false
+
+		for {
+			select {
+			case <-r.ticker.C:
+				r.tick()
+			case rd := <-r.Ready():
+				if rd.SoftState != nil {
+					newLeader := rd.SoftState.Lead != raft.None && rh.getLead() != rd.SoftState.Lead
+					if newLeader {
+						leaderChanges.Inc()
+					}
+
+					if rd.SoftState.Lead == raft.None {
+						hasLeader.Set(0)
+					} else {
+						hasLeader.Set(1)
+					}
+
+					rh.updateLead(rd.SoftState.Lead)
+					islead = rd.RaftState == raft.StateLeader
+					if islead {
+						isLeader.Set(1)
+					} else {
+						isLeader.Set(0)
+					}
+					rh.updateLeadership(newLeader)
+					r.td.Reset()
+				}
+
+				if len(rd.ReadStates) != 0 {
+					select {
+					case r.readStateC <- rd.ReadStates[len(rd.ReadStates)-1]:
+					case <-time.After(internalTimeout):
+						if r.lg != nil {
+							r.lg.Warn("timed out sending read state", zap.Duration("timeout", internalTimeout))
+						} else {
+							plog.Warningf("timed out sending read state")
+						}
+					case <-r.stopped:
+						return
+					}
+				}
+
+				notifyc := make(chan struct{}, 1)
+				ap := apply{
+					entries:  rd.CommittedEntries,
+					snapshot: rd.Snapshot,
+					notifyc:  notifyc,
+				}
+
+				updateCommittedIndex(&ap, rh)
+
+				select {
+				case r.applyc <- ap:
+				case <-r.stopped:
+					return
+				}
+
+				// the leader can write to its disk in parallel with replicating to the followers and them
+				// writing to their disks.
+				// For more details, check raft thesis 10.2.1
+				if islead {
+					// gofail: var raftBeforeLeaderSend struct{}
+					r.transport.Send(r.processMessages(rd.Messages))
+				}
+
+				// gofail: var raftBeforeSave struct{}
+				if err := r.storage.Save(rd.HardState, rd.Entries); err != nil {
+					if r.lg != nil {
+						r.lg.Fatal("failed to save Raft hard state and entries", zap.Error(err))
+					} else {
+						plog.Fatalf("raft save state and entries error: %v", err)
+					}
+				}
+				if !raft.IsEmptyHardState(rd.HardState) {
+					proposalsCommitted.Set(float64(rd.HardState.Commit))
+				}
+				// gofail: var raftAfterSave struct{}
+
+				if !raft.IsEmptySnap(rd.Snapshot) {
+					// gofail: var raftBeforeSaveSnap struct{}
+					if err := r.storage.SaveSnap(rd.Snapshot); err != nil {
+						if r.lg != nil {
+							r.lg.Fatal("failed to save Raft snapshot", zap.Error(err))
+						} else {
+							plog.Fatalf("raft save snapshot error: %v", err)
+						}
+					}
+					// etcdserver now claim the snapshot has been persisted onto the disk
+					notifyc <- struct{}{}
+
+					// gofail: var raftAfterSaveSnap struct{}
+					r.raftStorage.ApplySnapshot(rd.Snapshot)
+					if r.lg != nil {
+						r.lg.Info("applied incoming Raft snapshot", zap.Uint64("snapshot-index", rd.Snapshot.Metadata.Index))
+					} else {
+						plog.Infof("raft applied incoming snapshot at index %d", rd.Snapshot.Metadata.Index)
+					}
+					// gofail: var raftAfterApplySnap struct{}
+				}
+
+				r.raftStorage.Append(rd.Entries)
+
+				if !islead {
+					// finish processing incoming messages before we signal raftdone chan
+					msgs := r.processMessages(rd.Messages)
+
+					// now unblocks 'applyAll' that waits on Raft log disk writes before triggering snapshots
+					notifyc <- struct{}{}
+
+					// Candidate or follower needs to wait for all pending configuration
+					// changes to be applied before sending messages.
+					// Otherwise we might incorrectly count votes (e.g. votes from removed members).
+					// Also slow machine's follower raft-layer could proceed to become the leader
+					// on its own single-node cluster, before apply-layer applies the config change.
+					// We simply wait for ALL pending entries to be applied for now.
+					// We might improve this later on if it causes unnecessary long blocking issues.
+					waitApply := false
+					for _, ent := range rd.CommittedEntries {
+						if ent.Type == raftpb.EntryConfChange {
+							waitApply = true
+							break
+						}
+					}
+					if waitApply {
+						// blocks until 'applyAll' calls 'applyWait.Trigger'
+						// to be in sync with scheduled config-change job
+						// (assume notifyc has cap of 1)
+						select {
+						case notifyc <- struct{}{}:
+						case <-r.stopped:
+							return
+						}
+					}
+
+					// gofail: var raftBeforeFollowerSend struct{}
+					r.transport.Send(msgs)
+				} else {
+					// leader already processed 'MsgSnap' and signaled
+					notifyc <- struct{}{}
+				}
+
+				r.Advance()
+			case <-r.stopped:
+				return
+			}
+		}
+	}()
+}
+
+func updateCommittedIndex(ap *apply, rh *raftReadyHandler) {
+	var ci uint64
+	if len(ap.entries) != 0 {
+		ci = ap.entries[len(ap.entries)-1].Index
+	}
+	if ap.snapshot.Metadata.Index > ci {
+		ci = ap.snapshot.Metadata.Index
+	}
+	if ci != 0 {
+		rh.updateCommittedIndex(ci)
+	}
+}
+
+func (r *raftNode) processMessages(ms []raftpb.Message) []raftpb.Message {
+	sentAppResp := false
+	for i := len(ms) - 1; i >= 0; i-- {
+		if r.isIDRemoved(ms[i].To) {
+			ms[i].To = 0
+		}
+
+		if ms[i].Type == raftpb.MsgAppResp {
+			if sentAppResp {
+				ms[i].To = 0
+			} else {
+				sentAppResp = true
+			}
+		}
+
+		if ms[i].Type == raftpb.MsgSnap {
+			// There are two separate data store: the store for v2, and the KV for v3.
+			// The msgSnap only contains the most recent snapshot of store without KV.
+			// So we need to redirect the msgSnap to etcd server main loop for merging in the
+			// current store snapshot and KV snapshot.
+			select {
+			case r.msgSnapC <- ms[i]:
+			default:
+				// drop msgSnap if the inflight chan if full.
+			}
+			ms[i].To = 0
+		}
+		if ms[i].Type == raftpb.MsgHeartbeat {
+			ok, exceed := r.td.Observe(ms[i].To)
+			if !ok {
+				// TODO: limit request rate.
+				if r.lg != nil {
+					r.lg.Warn(
+						"leader failed to send out heartbeat on time; took too long, leader is overloaded likely from slow disk",
+						zap.String("to", fmt.Sprintf("%x", ms[i].To)),
+						zap.Duration("heartbeat-interval", r.heartbeat),
+						zap.Duration("expected-duration", 2*r.heartbeat),
+						zap.Duration("exceeded-duration", exceed),
+					)
+				} else {
+					plog.Warningf("failed to send out heartbeat on time (exceeded the %v timeout for %v, to %x)", r.heartbeat, exceed, ms[i].To)
+					plog.Warningf("server is likely overloaded")
+				}
+				heartbeatSendFailures.Inc()
+			}
+		}
+	}
+	return ms
+}
+
+func (r *raftNode) apply() chan apply {
+	return r.applyc
+}
+
+func (r *raftNode) stop() {
+	r.stopped <- struct{}{}
+	<-r.done
+}
+
+func (r *raftNode) onStop() {
+	r.Stop()
+	r.ticker.Stop()
+	r.transport.Stop()
+	if err := r.storage.Close(); err != nil {
+		if r.lg != nil {
+			r.lg.Panic("failed to close Raft storage", zap.Error(err))
+		} else {
+			plog.Panicf("raft close storage error: %v", err)
+		}
+	}
+	close(r.done)
+}
+
+// for testing
+func (r *raftNode) pauseSending() {
+	p := r.transport.(rafthttp.Pausable)
+	p.Pause()
+}
+
+func (r *raftNode) resumeSending() {
+	p := r.transport.(rafthttp.Pausable)
+	p.Resume()
+}
+
+// advanceTicks advances ticks of Raft node.
+// This can be used for fast-forwarding election
+// ticks in multi data-center deployments, thus
+// speeding up election process.
+func (r *raftNode) advanceTicks(ticks int) {
+	for i := 0; i < ticks; i++ {
+		r.tick()
+	}
+}
+
+func startNode(cfg ServerConfig, cl *membership.RaftCluster, ids []types.ID) (id types.ID, n raft.Node, s *raft.MemoryStorage, w *wal.WAL) {
+	var err error
+	member := cl.MemberByName(cfg.Name)
+	metadata := pbutil.MustMarshal(
+		&pb.Metadata{
+			NodeID:    uint64(member.ID),
+			ClusterID: uint64(cl.ID()),
+		},
+	)
+	if w, err = wal.Create(cfg.Logger, cfg.WALDir(), metadata); err != nil {
+		if cfg.Logger != nil {
+			cfg.Logger.Panic("failed to create WAL", zap.Error(err))
+		} else {
+			plog.Panicf("create wal error: %v", err)
+		}
+	}
+	peers := make([]raft.Peer, len(ids))
+	for i, id := range ids {
+		var ctx []byte
+		ctx, err = json.Marshal((*cl).Member(id))
+		if err != nil {
+			if cfg.Logger != nil {
+				cfg.Logger.Panic("failed to marshal member", zap.Error(err))
+			} else {
+				plog.Panicf("marshal member should never fail: %v", err)
+			}
+		}
+		peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
+	}
+	id = member.ID
+	if cfg.Logger != nil {
+		cfg.Logger.Info(
+			"starting local member",
+			zap.String("local-member-id", id.String()),
+			zap.String("cluster-id", cl.ID().String()),
+		)
+	} else {
+		plog.Infof("starting member %s in cluster %s", id, cl.ID())
+	}
+	s = raft.NewMemoryStorage()
+	c := &raft.Config{
+		ID:              uint64(id),
+		ElectionTick:    cfg.ElectionTicks,
+		HeartbeatTick:   1,
+		Storage:         s,
+		MaxSizePerMsg:   maxSizePerMsg,
+		MaxInflightMsgs: maxInflightMsgs,
+		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
+	}
+	if cfg.Logger != nil {
+		// called after capnslog setting in "init" function
+		if cfg.LoggerConfig != nil {
+			c.Logger, err = logutil.NewRaftLogger(cfg.LoggerConfig)
+			if err != nil {
+				log.Fatalf("cannot create raft logger %v", err)
+			}
+		} else if cfg.LoggerCore != nil && cfg.LoggerWriteSyncer != nil {
+			c.Logger = logutil.NewRaftLoggerFromZapCore(cfg.LoggerCore, cfg.LoggerWriteSyncer)
+		}
+	}
+
+	if len(peers) == 0 {
+		n = raft.RestartNode(c)
+	} else {
+		n = raft.StartNode(c, peers)
+	}
+	raftStatusMu.Lock()
+	raftStatus = n.Status
+	raftStatusMu.Unlock()
+	return id, n, s, w
+}
+
+func restartNode(cfg ServerConfig, snapshot *raftpb.Snapshot) (types.ID, *membership.RaftCluster, raft.Node, *raft.MemoryStorage, *wal.WAL) {
+	var walsnap walpb.Snapshot
+	if snapshot != nil {
+		walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
+	}
+	w, id, cid, st, ents := readWAL(cfg.Logger, cfg.WALDir(), walsnap)
+
+	if cfg.Logger != nil {
+		cfg.Logger.Info(
+			"restarting local member",
+			zap.String("cluster-id", cid.String()),
+			zap.String("local-member-id", id.String()),
+			zap.Uint64("commit-index", st.Commit),
+		)
+	} else {
+		plog.Infof("restarting member %s in cluster %s at commit index %d", id, cid, st.Commit)
+	}
+	cl := membership.NewCluster(cfg.Logger, "")
+	cl.SetID(id, cid)
+	s := raft.NewMemoryStorage()
+	if snapshot != nil {
+		s.ApplySnapshot(*snapshot)
+	}
+	s.SetHardState(st)
+	s.Append(ents)
+	c := &raft.Config{
+		ID:              uint64(id),
+		ElectionTick:    cfg.ElectionTicks,
+		HeartbeatTick:   1,
+		Storage:         s,
+		MaxSizePerMsg:   maxSizePerMsg,
+		MaxInflightMsgs: maxInflightMsgs,
+		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
+	}
+	if cfg.Logger != nil {
+		// called after capnslog setting in "init" function
+		var err error
+		if cfg.LoggerConfig != nil {
+			c.Logger, err = logutil.NewRaftLogger(cfg.LoggerConfig)
+			if err != nil {
+				log.Fatalf("cannot create raft logger %v", err)
+			}
+		} else if cfg.LoggerCore != nil && cfg.LoggerWriteSyncer != nil {
+			c.Logger = logutil.NewRaftLoggerFromZapCore(cfg.LoggerCore, cfg.LoggerWriteSyncer)
+		}
+	}
+
+	n := raft.RestartNode(c)
+	raftStatusMu.Lock()
+	raftStatus = n.Status
+	raftStatusMu.Unlock()
+	return id, cl, n, s, w
+}
+
+func restartAsStandaloneNode(cfg ServerConfig, snapshot *raftpb.Snapshot) (types.ID, *membership.RaftCluster, raft.Node, *raft.MemoryStorage, *wal.WAL) {
+	var walsnap walpb.Snapshot
+	if snapshot != nil {
+		walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
+	}
+	w, id, cid, st, ents := readWAL(cfg.Logger, cfg.WALDir(), walsnap)
+
+	// discard the previously uncommitted entries
+	for i, ent := range ents {
+		if ent.Index > st.Commit {
+			if cfg.Logger != nil {
+				cfg.Logger.Info(
+					"discarding uncommitted WAL entries",
+					zap.Uint64("entry-index", ent.Index),
+					zap.Uint64("commit-index-from-wal", st.Commit),
+					zap.Int("number-of-discarded-entries", len(ents)-i),
+				)
+			} else {
+				plog.Infof("discarding %d uncommitted WAL entries ", len(ents)-i)
+			}
+			ents = ents[:i]
+			break
+		}
+	}
+
+	// force append the configuration change entries
+	toAppEnts := createConfigChangeEnts(
+		cfg.Logger,
+		getIDs(cfg.Logger, snapshot, ents),
+		uint64(id),
+		st.Term,
+		st.Commit,
+	)
+	ents = append(ents, toAppEnts...)
+
+	// force commit newly appended entries
+	err := w.Save(raftpb.HardState{}, toAppEnts)
+	if err != nil {
+		if cfg.Logger != nil {
+			cfg.Logger.Fatal("failed to save hard state and entries", zap.Error(err))
+		} else {
+			plog.Fatalf("%v", err)
+		}
+	}
+	if len(ents) != 0 {
+		st.Commit = ents[len(ents)-1].Index
+	}
+
+	if cfg.Logger != nil {
+		cfg.Logger.Info(
+			"forcing restart member",
+			zap.String("cluster-id", cid.String()),
+			zap.String("local-member-id", id.String()),
+			zap.Uint64("commit-index", st.Commit),
+		)
+	} else {
+		plog.Printf("forcing restart of member %s in cluster %s at commit index %d", id, cid, st.Commit)
+	}
+
+	cl := membership.NewCluster(cfg.Logger, "")
+	cl.SetID(id, cid)
+	s := raft.NewMemoryStorage()
+	if snapshot != nil {
+		s.ApplySnapshot(*snapshot)
+	}
+	s.SetHardState(st)
+	s.Append(ents)
+	c := &raft.Config{
+		ID:              uint64(id),
+		ElectionTick:    cfg.ElectionTicks,
+		HeartbeatTick:   1,
+		Storage:         s,
+		MaxSizePerMsg:   maxSizePerMsg,
+		MaxInflightMsgs: maxInflightMsgs,
+		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
+	}
+	if cfg.Logger != nil {
+		// called after capnslog setting in "init" function
+		if cfg.LoggerConfig != nil {
+			c.Logger, err = logutil.NewRaftLogger(cfg.LoggerConfig)
+			if err != nil {
+				log.Fatalf("cannot create raft logger %v", err)
+			}
+		} else if cfg.LoggerCore != nil && cfg.LoggerWriteSyncer != nil {
+			c.Logger = logutil.NewRaftLoggerFromZapCore(cfg.LoggerCore, cfg.LoggerWriteSyncer)
+		}
+	}
+
+	n := raft.RestartNode(c)
+	raftStatus = n.Status
+	return id, cl, n, s, w
+}
+
+// getIDs returns an ordered set of IDs included in the given snapshot and
+// the entries. The given snapshot/entries can contain two kinds of
+// ID-related entry:
+// - ConfChangeAddNode, in which case the contained ID will be added into the set.
+// - ConfChangeRemoveNode, in which case the contained ID will be removed from the set.
+func getIDs(lg *zap.Logger, snap *raftpb.Snapshot, ents []raftpb.Entry) []uint64 {
+	ids := make(map[uint64]bool)
+	if snap != nil {
+		for _, id := range snap.Metadata.ConfState.Voters {
+			ids[id] = true
+		}
+	}
+	for _, e := range ents {
+		if e.Type != raftpb.EntryConfChange {
+			continue
+		}
+		var cc raftpb.ConfChange
+		pbutil.MustUnmarshal(&cc, e.Data)
+		switch cc.Type {
+		case raftpb.ConfChangeAddNode:
+			ids[cc.NodeID] = true
+		case raftpb.ConfChangeRemoveNode:
+			delete(ids, cc.NodeID)
+		case raftpb.ConfChangeUpdateNode:
+			// do nothing
+		default:
+			if lg != nil {
+				lg.Panic("unknown ConfChange Type", zap.String("type", cc.Type.String()))
+			} else {
+				plog.Panicf("ConfChange Type should be either ConfChangeAddNode or ConfChangeRemoveNode!")
+			}
+		}
+	}
+	sids := make(types.Uint64Slice, 0, len(ids))
+	for id := range ids {
+		sids = append(sids, id)
+	}
+	sort.Sort(sids)
+	return []uint64(sids)
+}
+
+// createConfigChangeEnts creates a series of Raft entries (i.e.
+// EntryConfChange) to remove the set of given IDs from the cluster. The ID
+// `self` is _not_ removed, even if present in the set.
+// If `self` is not inside the given ids, it creates a Raft entry to add a
+// default member with the given `self`.
+func createConfigChangeEnts(lg *zap.Logger, ids []uint64, self uint64, term, index uint64) []raftpb.Entry {
+	found := false
+	for _, id := range ids {
+		if id == self {
+			found = true
+		}
+	}
+
+	var ents []raftpb.Entry
+	next := index + 1
+
+	// NB: always add self first, then remove other nodes. Raft will panic if the
+	// set of voters ever becomes empty.
+	if !found {
+		m := membership.Member{
+			ID:             types.ID(self),
+			RaftAttributes: membership.RaftAttributes{PeerURLs: []string{"http://localhost:2380"}},
+		}
+		ctx, err := json.Marshal(m)
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to marshal member", zap.Error(err))
+			} else {
+				plog.Panicf("marshal member should never fail: %v", err)
+			}
+		}
+		cc := &raftpb.ConfChange{
+			Type:    raftpb.ConfChangeAddNode,
+			NodeID:  self,
+			Context: ctx,
+		}
+		e := raftpb.Entry{
+			Type:  raftpb.EntryConfChange,
+			Data:  pbutil.MustMarshal(cc),
+			Term:  term,
+			Index: next,
+		}
+		ents = append(ents, e)
+		next++
+	}
+
+	for _, id := range ids {
+		if id == self {
+			continue
+		}
+		cc := &raftpb.ConfChange{
+			Type:   raftpb.ConfChangeRemoveNode,
+			NodeID: id,
+		}
+		e := raftpb.Entry{
+			Type:  raftpb.EntryConfChange,
+			Data:  pbutil.MustMarshal(cc),
+			Term:  term,
+			Index: next,
+		}
+		ents = append(ents, e)
+		next++
+	}
+
+	return ents
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/server.go b/vendor/go.etcd.io/etcd/etcdserver/server.go
new file mode 100644
index 0000000..78daa0e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/server.go
@@ -0,0 +1,2656 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"context"
+	"encoding/json"
+	"expvar"
+	"fmt"
+	"math"
+	"math/rand"
+	"net/http"
+	"os"
+	"path"
+	"regexp"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"go.etcd.io/etcd/auth"
+	"go.etcd.io/etcd/etcdserver/api"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	"go.etcd.io/etcd/etcdserver/api/v2discovery"
+	"go.etcd.io/etcd/etcdserver/api/v2http/httptypes"
+	stats "go.etcd.io/etcd/etcdserver/api/v2stats"
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	"go.etcd.io/etcd/etcdserver/api/v3alarm"
+	"go.etcd.io/etcd/etcdserver/api/v3compactor"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/lease/leasehttp"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/pkg/fileutil"
+	"go.etcd.io/etcd/pkg/idutil"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/runtime"
+	"go.etcd.io/etcd/pkg/schedule"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/pkg/wait"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/version"
+	"go.etcd.io/etcd/wal"
+
+	"github.com/coreos/go-semver/semver"
+	"github.com/coreos/pkg/capnslog"
+	humanize "github.com/dustin/go-humanize"
+	"github.com/prometheus/client_golang/prometheus"
+	"go.uber.org/zap"
+)
+
+const (
+	DefaultSnapshotCount = 100000
+
+	// DefaultSnapshotCatchUpEntries is the number of entries for a slow follower
+	// to catch-up after compacting the raft storage entries.
+	// We expect the follower has a millisecond level latency with the leader.
+	// The max throughput is around 10K. Keep a 5K entries is enough for helping
+	// follower to catch up.
+	DefaultSnapshotCatchUpEntries uint64 = 5000
+
+	StoreClusterPrefix = "/0"
+	StoreKeysPrefix    = "/1"
+
+	// HealthInterval is the minimum time the cluster should be healthy
+	// before accepting add member requests.
+	HealthInterval = 5 * time.Second
+
+	purgeFileInterval = 30 * time.Second
+	// monitorVersionInterval should be smaller than the timeout
+	// on the connection. Or we will not be able to reuse the connection
+	// (since it will timeout).
+	monitorVersionInterval = rafthttp.ConnWriteTimeout - time.Second
+
+	// max number of in-flight snapshot messages etcdserver allows to have
+	// This number is more than enough for most clusters with 5 machines.
+	maxInFlightMsgSnap = 16
+
+	releaseDelayAfterSnapshot = 30 * time.Second
+
+	// maxPendingRevokes is the maximum number of outstanding expired lease revocations.
+	maxPendingRevokes = 16
+
+	recommendedMaxRequestBytes = 10 * 1024 * 1024
+
+	readyPercent = 0.9
+)
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver")
+
+	storeMemberAttributeRegexp = regexp.MustCompile(path.Join(membership.StoreMembersPrefix, "[[:xdigit:]]{1,16}", "attributes"))
+)
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+
+	expvar.Publish(
+		"file_descriptor_limit",
+		expvar.Func(
+			func() interface{} {
+				n, _ := runtime.FDLimit()
+				return n
+			},
+		),
+	)
+}
+
+type Response struct {
+	Term    uint64
+	Index   uint64
+	Event   *v2store.Event
+	Watcher v2store.Watcher
+	Err     error
+}
+
+type ServerV2 interface {
+	Server
+	Leader() types.ID
+
+	// Do takes a V2 request and attempts to fulfill it, returning a Response.
+	Do(ctx context.Context, r pb.Request) (Response, error)
+	stats.Stats
+	ClientCertAuthEnabled() bool
+}
+
+type ServerV3 interface {
+	Server
+	RaftStatusGetter
+}
+
+func (s *EtcdServer) ClientCertAuthEnabled() bool { return s.Cfg.ClientCertAuthEnabled }
+
+type Server interface {
+	// AddMember attempts to add a member into the cluster. It will return
+	// ErrIDRemoved if member ID is removed from the cluster, or return
+	// ErrIDExists if member ID exists in the cluster.
+	AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error)
+	// RemoveMember attempts to remove a member from the cluster. It will
+	// return ErrIDRemoved if member ID is removed from the cluster, or return
+	// ErrIDNotFound if member ID is not in the cluster.
+	RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error)
+	// UpdateMember attempts to update an existing member in the cluster. It will
+	// return ErrIDNotFound if the member ID does not exist.
+	UpdateMember(ctx context.Context, updateMemb membership.Member) ([]*membership.Member, error)
+	// PromoteMember attempts to promote a non-voting node to a voting node. It will
+	// return ErrIDNotFound if the member ID does not exist.
+	// return ErrLearnerNotReady if the member are not ready.
+	// return ErrMemberNotLearner if the member is not a learner.
+	PromoteMember(ctx context.Context, id uint64) ([]*membership.Member, error)
+
+	// ClusterVersion is the cluster-wide minimum major.minor version.
+	// Cluster version is set to the min version that an etcd member is
+	// compatible with when first bootstrap.
+	//
+	// ClusterVersion is nil until the cluster is bootstrapped (has a quorum).
+	//
+	// During a rolling upgrades, the ClusterVersion will be updated
+	// automatically after a sync. (5 second by default)
+	//
+	// The API/raft component can utilize ClusterVersion to determine if
+	// it can accept a client request or a raft RPC.
+	// NOTE: ClusterVersion might be nil when etcd 2.1 works with etcd 2.0 and
+	// the leader is etcd 2.0. etcd 2.0 leader will not update clusterVersion since
+	// this feature is introduced post 2.0.
+	ClusterVersion() *semver.Version
+	Cluster() api.Cluster
+	Alarms() []*pb.AlarmMember
+}
+
+// EtcdServer is the production implementation of the Server interface
+type EtcdServer struct {
+	// inflightSnapshots holds count the number of snapshots currently inflight.
+	inflightSnapshots int64  // must use atomic operations to access; keep 64-bit aligned.
+	appliedIndex      uint64 // must use atomic operations to access; keep 64-bit aligned.
+	committedIndex    uint64 // must use atomic operations to access; keep 64-bit aligned.
+	term              uint64 // must use atomic operations to access; keep 64-bit aligned.
+	lead              uint64 // must use atomic operations to access; keep 64-bit aligned.
+
+	// consistIndex used to hold the offset of current executing entry
+	// It is initialized to 0 before executing any entry.
+	consistIndex consistentIndex // must use atomic operations to access; keep 64-bit aligned.
+	r            raftNode        // uses 64-bit atomics; keep 64-bit aligned.
+
+	readych chan struct{}
+	Cfg     ServerConfig
+
+	lgMu *sync.RWMutex
+	lg   *zap.Logger
+
+	w wait.Wait
+
+	readMu sync.RWMutex
+	// read routine notifies etcd server that it waits for reading by sending an empty struct to
+	// readwaitC
+	readwaitc chan struct{}
+	// readNotifier is used to notify the read routine that it can process the request
+	// when there is no error
+	readNotifier *notifier
+
+	// stop signals the run goroutine should shutdown.
+	stop chan struct{}
+	// stopping is closed by run goroutine on shutdown.
+	stopping chan struct{}
+	// done is closed when all goroutines from start() complete.
+	done chan struct{}
+	// leaderChanged is used to notify the linearizable read loop to drop the old read requests.
+	leaderChanged   chan struct{}
+	leaderChangedMu sync.RWMutex
+
+	errorc     chan error
+	id         types.ID
+	attributes membership.Attributes
+
+	cluster *membership.RaftCluster
+
+	v2store     v2store.Store
+	snapshotter *snap.Snapshotter
+
+	applyV2 ApplierV2
+
+	// applyV3 is the applier with auth and quotas
+	applyV3 applierV3
+	// applyV3Base is the core applier without auth or quotas
+	applyV3Base applierV3
+	applyWait   wait.WaitTime
+
+	kv         mvcc.ConsistentWatchableKV
+	lessor     lease.Lessor
+	bemu       sync.Mutex
+	be         backend.Backend
+	authStore  auth.AuthStore
+	alarmStore *v3alarm.AlarmStore
+
+	stats  *stats.ServerStats
+	lstats *stats.LeaderStats
+
+	SyncTicker *time.Ticker
+	// compactor is used to auto-compact the KV.
+	compactor v3compactor.Compactor
+
+	// peerRt used to send requests (version, lease) to peers.
+	peerRt   http.RoundTripper
+	reqIDGen *idutil.Generator
+
+	// forceVersionC is used to force the version monitor loop
+	// to detect the cluster version immediately.
+	forceVersionC chan struct{}
+
+	// wgMu blocks concurrent waitgroup mutation while server stopping
+	wgMu sync.RWMutex
+	// wg is used to wait for the go routines that depends on the server state
+	// to exit when stopping the server.
+	wg sync.WaitGroup
+
+	// ctx is used for etcd-initiated requests that may need to be canceled
+	// on etcd server shutdown.
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	leadTimeMu      sync.RWMutex
+	leadElectedTime time.Time
+
+	*AccessController
+}
+
+// NewServer creates a new EtcdServer from the supplied configuration. The
+// configuration is considered static for the lifetime of the EtcdServer.
+func NewServer(cfg ServerConfig) (srv *EtcdServer, err error) {
+	st := v2store.New(StoreClusterPrefix, StoreKeysPrefix)
+
+	var (
+		w  *wal.WAL
+		n  raft.Node
+		s  *raft.MemoryStorage
+		id types.ID
+		cl *membership.RaftCluster
+	)
+
+	if cfg.MaxRequestBytes > recommendedMaxRequestBytes {
+		if cfg.Logger != nil {
+			cfg.Logger.Warn(
+				"exceeded recommended request limit",
+				zap.Uint("max-request-bytes", cfg.MaxRequestBytes),
+				zap.String("max-request-size", humanize.Bytes(uint64(cfg.MaxRequestBytes))),
+				zap.Int("recommended-request-bytes", recommendedMaxRequestBytes),
+				zap.String("recommended-request-size", humanize.Bytes(uint64(recommendedMaxRequestBytes))),
+			)
+		} else {
+			plog.Warningf("MaxRequestBytes %v exceeds maximum recommended size %v", cfg.MaxRequestBytes, recommendedMaxRequestBytes)
+		}
+	}
+
+	if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil {
+		return nil, fmt.Errorf("cannot access data directory: %v", terr)
+	}
+
+	haveWAL := wal.Exist(cfg.WALDir())
+
+	if err = fileutil.TouchDirAll(cfg.SnapDir()); err != nil {
+		if cfg.Logger != nil {
+			cfg.Logger.Fatal(
+				"failed to create snapshot directory",
+				zap.String("path", cfg.SnapDir()),
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("create snapshot directory error: %v", err)
+		}
+	}
+	ss := snap.New(cfg.Logger, cfg.SnapDir())
+
+	bepath := cfg.backendPath()
+	beExist := fileutil.Exist(bepath)
+	be := openBackend(cfg)
+
+	defer func() {
+		if err != nil {
+			be.Close()
+		}
+	}()
+
+	prt, err := rafthttp.NewRoundTripper(cfg.PeerTLSInfo, cfg.peerDialTimeout())
+	if err != nil {
+		return nil, err
+	}
+	var (
+		remotes  []*membership.Member
+		snapshot *raftpb.Snapshot
+	)
+
+	switch {
+	case !haveWAL && !cfg.NewCluster:
+		if err = cfg.VerifyJoinExisting(); err != nil {
+			return nil, err
+		}
+		cl, err = membership.NewClusterFromURLsMap(cfg.Logger, cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
+		if err != nil {
+			return nil, err
+		}
+		existingCluster, gerr := GetClusterFromRemotePeers(cfg.Logger, getRemotePeerURLs(cl, cfg.Name), prt)
+		if gerr != nil {
+			return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", gerr)
+		}
+		if err = membership.ValidateClusterAndAssignIDs(cfg.Logger, cl, existingCluster); err != nil {
+			return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
+		}
+		if !isCompatibleWithCluster(cfg.Logger, cl, cl.MemberByName(cfg.Name).ID, prt) {
+			return nil, fmt.Errorf("incompatible with current running cluster")
+		}
+
+		remotes = existingCluster.Members()
+		cl.SetID(types.ID(0), existingCluster.ID())
+		cl.SetStore(st)
+		cl.SetBackend(be)
+		id, n, s, w = startNode(cfg, cl, nil)
+		cl.SetID(id, existingCluster.ID())
+
+	case !haveWAL && cfg.NewCluster:
+		if err = cfg.VerifyBootstrap(); err != nil {
+			return nil, err
+		}
+		cl, err = membership.NewClusterFromURLsMap(cfg.Logger, cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
+		if err != nil {
+			return nil, err
+		}
+		m := cl.MemberByName(cfg.Name)
+		if isMemberBootstrapped(cfg.Logger, cl, cfg.Name, prt, cfg.bootstrapTimeout()) {
+			return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID)
+		}
+		if cfg.ShouldDiscover() {
+			var str string
+			str, err = v2discovery.JoinCluster(cfg.Logger, cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String())
+			if err != nil {
+				return nil, &DiscoveryError{Op: "join", Err: err}
+			}
+			var urlsmap types.URLsMap
+			urlsmap, err = types.NewURLsMap(str)
+			if err != nil {
+				return nil, err
+			}
+			if checkDuplicateURL(urlsmap) {
+				return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap)
+			}
+			if cl, err = membership.NewClusterFromURLsMap(cfg.Logger, cfg.InitialClusterToken, urlsmap); err != nil {
+				return nil, err
+			}
+		}
+		cl.SetStore(st)
+		cl.SetBackend(be)
+		id, n, s, w = startNode(cfg, cl, cl.MemberIDs())
+		cl.SetID(id, cl.ID())
+
+	case haveWAL:
+		if err = fileutil.IsDirWriteable(cfg.MemberDir()); err != nil {
+			return nil, fmt.Errorf("cannot write to member directory: %v", err)
+		}
+
+		if err = fileutil.IsDirWriteable(cfg.WALDir()); err != nil {
+			return nil, fmt.Errorf("cannot write to WAL directory: %v", err)
+		}
+
+		if cfg.ShouldDiscover() {
+			if cfg.Logger != nil {
+				cfg.Logger.Warn(
+					"discovery token is ignored since cluster already initialized; valid logs are found",
+					zap.String("wal-dir", cfg.WALDir()),
+				)
+			} else {
+				plog.Warningf("discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir())
+			}
+		}
+		snapshot, err = ss.Load()
+		if err != nil && err != snap.ErrNoSnapshot {
+			return nil, err
+		}
+		if snapshot != nil {
+			if err = st.Recovery(snapshot.Data); err != nil {
+				if cfg.Logger != nil {
+					cfg.Logger.Panic("failed to recover from snapshot")
+				} else {
+					plog.Panicf("recovered store from snapshot error: %v", err)
+				}
+			}
+
+			if cfg.Logger != nil {
+				cfg.Logger.Info(
+					"recovered v2 store from snapshot",
+					zap.Uint64("snapshot-index", snapshot.Metadata.Index),
+					zap.String("snapshot-size", humanize.Bytes(uint64(snapshot.Size()))),
+				)
+			} else {
+				plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index)
+			}
+
+			if be, err = recoverSnapshotBackend(cfg, be, *snapshot); err != nil {
+				if cfg.Logger != nil {
+					cfg.Logger.Panic("failed to recover v3 backend from snapshot", zap.Error(err))
+				} else {
+					plog.Panicf("recovering backend from snapshot error: %v", err)
+				}
+			}
+			if cfg.Logger != nil {
+				s1, s2 := be.Size(), be.SizeInUse()
+				cfg.Logger.Info(
+					"recovered v3 backend from snapshot",
+					zap.Int64("backend-size-bytes", s1),
+					zap.String("backend-size", humanize.Bytes(uint64(s1))),
+					zap.Int64("backend-size-in-use-bytes", s2),
+					zap.String("backend-size-in-use", humanize.Bytes(uint64(s2))),
+				)
+			}
+		}
+
+		if !cfg.ForceNewCluster {
+			id, cl, n, s, w = restartNode(cfg, snapshot)
+		} else {
+			id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot)
+		}
+
+		cl.SetStore(st)
+		cl.SetBackend(be)
+		cl.Recover(api.UpdateCapability)
+		if cl.Version() != nil && !cl.Version().LessThan(semver.Version{Major: 3}) && !beExist {
+			os.RemoveAll(bepath)
+			return nil, fmt.Errorf("database file (%v) of the backend is missing", bepath)
+		}
+
+	default:
+		return nil, fmt.Errorf("unsupported bootstrap config")
+	}
+
+	if terr := fileutil.TouchDirAll(cfg.MemberDir()); terr != nil {
+		return nil, fmt.Errorf("cannot access member directory: %v", terr)
+	}
+
+	sstats := stats.NewServerStats(cfg.Name, id.String())
+	lstats := stats.NewLeaderStats(id.String())
+
+	heartbeat := time.Duration(cfg.TickMs) * time.Millisecond
+	srv = &EtcdServer{
+		readych:     make(chan struct{}),
+		Cfg:         cfg,
+		lgMu:        new(sync.RWMutex),
+		lg:          cfg.Logger,
+		errorc:      make(chan error, 1),
+		v2store:     st,
+		snapshotter: ss,
+		r: *newRaftNode(
+			raftNodeConfig{
+				lg:          cfg.Logger,
+				isIDRemoved: func(id uint64) bool { return cl.IsIDRemoved(types.ID(id)) },
+				Node:        n,
+				heartbeat:   heartbeat,
+				raftStorage: s,
+				storage:     NewStorage(w, ss),
+			},
+		),
+		id:               id,
+		attributes:       membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
+		cluster:          cl,
+		stats:            sstats,
+		lstats:           lstats,
+		SyncTicker:       time.NewTicker(500 * time.Millisecond),
+		peerRt:           prt,
+		reqIDGen:         idutil.NewGenerator(uint16(id), time.Now()),
+		forceVersionC:    make(chan struct{}),
+		AccessController: &AccessController{CORS: cfg.CORS, HostWhitelist: cfg.HostWhitelist},
+	}
+	serverID.With(prometheus.Labels{"server_id": id.String()}).Set(1)
+
+	srv.applyV2 = &applierV2store{store: srv.v2store, cluster: srv.cluster}
+
+	srv.be = be
+	minTTL := time.Duration((3*cfg.ElectionTicks)/2) * heartbeat
+
+	// always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases.
+	// If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers.
+	srv.lessor = lease.NewLessor(
+		srv.getLogger(),
+		srv.be,
+		lease.LessorConfig{
+			MinLeaseTTL:                int64(math.Ceil(minTTL.Seconds())),
+			CheckpointInterval:         cfg.LeaseCheckpointInterval,
+			ExpiredLeasesRetryInterval: srv.Cfg.ReqTimeout(),
+		})
+	srv.kv = mvcc.New(srv.getLogger(), srv.be, srv.lessor, &srv.consistIndex, mvcc.StoreConfig{CompactionBatchLimit: cfg.CompactionBatchLimit})
+	if beExist {
+		kvindex := srv.kv.ConsistentIndex()
+		// TODO: remove kvindex != 0 checking when we do not expect users to upgrade
+		// etcd from pre-3.0 release.
+		if snapshot != nil && kvindex < snapshot.Metadata.Index {
+			if kvindex != 0 {
+				return nil, fmt.Errorf("database file (%v index %d) does not match with snapshot (index %d)", bepath, kvindex, snapshot.Metadata.Index)
+			}
+			if cfg.Logger != nil {
+				cfg.Logger.Warn(
+					"consistent index was never saved",
+					zap.Uint64("snapshot-index", snapshot.Metadata.Index),
+				)
+			} else {
+				plog.Warningf("consistent index never saved (snapshot index=%d)", snapshot.Metadata.Index)
+			}
+		}
+	}
+	newSrv := srv // since srv == nil in defer if srv is returned as nil
+	defer func() {
+		// closing backend without first closing kv can cause
+		// resumed compactions to fail with closed tx errors
+		if err != nil {
+			newSrv.kv.Close()
+		}
+	}()
+
+	srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex())
+	tp, err := auth.NewTokenProvider(cfg.Logger, cfg.AuthToken,
+		func(index uint64) <-chan struct{} {
+			return srv.applyWait.Wait(index)
+		},
+	)
+	if err != nil {
+		if cfg.Logger != nil {
+			cfg.Logger.Warn("failed to create token provider", zap.Error(err))
+		} else {
+			plog.Errorf("failed to create token provider: %s", err)
+		}
+		return nil, err
+	}
+	srv.authStore = auth.NewAuthStore(srv.getLogger(), srv.be, tp, int(cfg.BcryptCost))
+	if num := cfg.AutoCompactionRetention; num != 0 {
+		srv.compactor, err = v3compactor.New(cfg.Logger, cfg.AutoCompactionMode, num, srv.kv, srv)
+		if err != nil {
+			return nil, err
+		}
+		srv.compactor.Run()
+	}
+
+	srv.applyV3Base = srv.newApplierV3Backend()
+	if err = srv.restoreAlarms(); err != nil {
+		return nil, err
+	}
+
+	if srv.Cfg.EnableLeaseCheckpoint {
+		// setting checkpointer enables lease checkpoint feature.
+		srv.lessor.SetCheckpointer(func(ctx context.Context, cp *pb.LeaseCheckpointRequest) {
+			srv.raftRequestOnce(ctx, pb.InternalRaftRequest{LeaseCheckpoint: cp})
+		})
+	}
+
+	// TODO: move transport initialization near the definition of remote
+	tr := &rafthttp.Transport{
+		Logger:      cfg.Logger,
+		TLSInfo:     cfg.PeerTLSInfo,
+		DialTimeout: cfg.peerDialTimeout(),
+		ID:          id,
+		URLs:        cfg.PeerURLs,
+		ClusterID:   cl.ID(),
+		Raft:        srv,
+		Snapshotter: ss,
+		ServerStats: sstats,
+		LeaderStats: lstats,
+		ErrorC:      srv.errorc,
+	}
+	if err = tr.Start(); err != nil {
+		return nil, err
+	}
+	// add all remotes into transport
+	for _, m := range remotes {
+		if m.ID != id {
+			tr.AddRemote(m.ID, m.PeerURLs)
+		}
+	}
+	for _, m := range cl.Members() {
+		if m.ID != id {
+			tr.AddPeer(m.ID, m.PeerURLs)
+		}
+	}
+	srv.r.transport = tr
+
+	return srv, nil
+}
+
+func (s *EtcdServer) getLogger() *zap.Logger {
+	s.lgMu.RLock()
+	l := s.lg
+	s.lgMu.RUnlock()
+	return l
+}
+
+func tickToDur(ticks int, tickMs uint) string {
+	return fmt.Sprintf("%v", time.Duration(ticks)*time.Duration(tickMs)*time.Millisecond)
+}
+
+func (s *EtcdServer) adjustTicks() {
+	lg := s.getLogger()
+	clusterN := len(s.cluster.Members())
+
+	// single-node fresh start, or single-node recovers from snapshot
+	if clusterN == 1 {
+		ticks := s.Cfg.ElectionTicks - 1
+		if lg != nil {
+			lg.Info(
+				"started as single-node; fast-forwarding election ticks",
+				zap.String("local-member-id", s.ID().String()),
+				zap.Int("forward-ticks", ticks),
+				zap.String("forward-duration", tickToDur(ticks, s.Cfg.TickMs)),
+				zap.Int("election-ticks", s.Cfg.ElectionTicks),
+				zap.String("election-timeout", tickToDur(s.Cfg.ElectionTicks, s.Cfg.TickMs)),
+			)
+		} else {
+			plog.Infof("%s as single-node; fast-forwarding %d ticks (election ticks %d)", s.ID(), ticks, s.Cfg.ElectionTicks)
+		}
+		s.r.advanceTicks(ticks)
+		return
+	}
+
+	if !s.Cfg.InitialElectionTickAdvance {
+		if lg != nil {
+			lg.Info("skipping initial election tick advance", zap.Int("election-ticks", s.Cfg.ElectionTicks))
+		}
+		return
+	}
+	if lg != nil {
+		lg.Info("starting initial election tick advance", zap.Int("election-ticks", s.Cfg.ElectionTicks))
+	}
+
+	// retry up to "rafthttp.ConnReadTimeout", which is 5-sec
+	// until peer connection reports; otherwise:
+	// 1. all connections failed, or
+	// 2. no active peers, or
+	// 3. restarted single-node with no snapshot
+	// then, do nothing, because advancing ticks would have no effect
+	waitTime := rafthttp.ConnReadTimeout
+	itv := 50 * time.Millisecond
+	for i := int64(0); i < int64(waitTime/itv); i++ {
+		select {
+		case <-time.After(itv):
+		case <-s.stopping:
+			return
+		}
+
+		peerN := s.r.transport.ActivePeers()
+		if peerN > 1 {
+			// multi-node received peer connection reports
+			// adjust ticks, in case slow leader message receive
+			ticks := s.Cfg.ElectionTicks - 2
+
+			if lg != nil {
+				lg.Info(
+					"initialized peer connections; fast-forwarding election ticks",
+					zap.String("local-member-id", s.ID().String()),
+					zap.Int("forward-ticks", ticks),
+					zap.String("forward-duration", tickToDur(ticks, s.Cfg.TickMs)),
+					zap.Int("election-ticks", s.Cfg.ElectionTicks),
+					zap.String("election-timeout", tickToDur(s.Cfg.ElectionTicks, s.Cfg.TickMs)),
+					zap.Int("active-remote-members", peerN),
+				)
+			} else {
+				plog.Infof("%s initialized peer connection; fast-forwarding %d ticks (election ticks %d) with %d active peer(s)", s.ID(), ticks, s.Cfg.ElectionTicks, peerN)
+			}
+
+			s.r.advanceTicks(ticks)
+			return
+		}
+	}
+}
+
+// Start performs any initialization of the Server necessary for it to
+// begin serving requests. It must be called before Do or Process.
+// Start must be non-blocking; any long-running server functionality
+// should be implemented in goroutines.
+func (s *EtcdServer) Start() {
+	s.start()
+	s.goAttach(func() { s.adjustTicks() })
+	s.goAttach(func() { s.publish(s.Cfg.ReqTimeout()) })
+	s.goAttach(s.purgeFile)
+	s.goAttach(func() { monitorFileDescriptor(s.getLogger(), s.stopping) })
+	s.goAttach(s.monitorVersions)
+	s.goAttach(s.linearizableReadLoop)
+	s.goAttach(s.monitorKVHash)
+}
+
+// start prepares and starts server in a new goroutine. It is no longer safe to
+// modify a server's fields after it has been sent to Start.
+// This function is just used for testing.
+func (s *EtcdServer) start() {
+	lg := s.getLogger()
+
+	if s.Cfg.SnapshotCount == 0 {
+		if lg != nil {
+			lg.Info(
+				"updating snapshot-count to default",
+				zap.Uint64("given-snapshot-count", s.Cfg.SnapshotCount),
+				zap.Uint64("updated-snapshot-count", DefaultSnapshotCount),
+			)
+		} else {
+			plog.Infof("set snapshot count to default %d", DefaultSnapshotCount)
+		}
+		s.Cfg.SnapshotCount = DefaultSnapshotCount
+	}
+	if s.Cfg.SnapshotCatchUpEntries == 0 {
+		if lg != nil {
+			lg.Info(
+				"updating snapshot catch-up entries to default",
+				zap.Uint64("given-snapshot-catchup-entries", s.Cfg.SnapshotCatchUpEntries),
+				zap.Uint64("updated-snapshot-catchup-entries", DefaultSnapshotCatchUpEntries),
+			)
+		}
+		s.Cfg.SnapshotCatchUpEntries = DefaultSnapshotCatchUpEntries
+	}
+
+	s.w = wait.New()
+	s.applyWait = wait.NewTimeList()
+	s.done = make(chan struct{})
+	s.stop = make(chan struct{})
+	s.stopping = make(chan struct{})
+	s.ctx, s.cancel = context.WithCancel(context.Background())
+	s.readwaitc = make(chan struct{}, 1)
+	s.readNotifier = newNotifier()
+	s.leaderChanged = make(chan struct{})
+	if s.ClusterVersion() != nil {
+		if lg != nil {
+			lg.Info(
+				"starting etcd server",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("local-server-version", version.Version),
+				zap.String("cluster-id", s.Cluster().ID().String()),
+				zap.String("cluster-version", version.Cluster(s.ClusterVersion().String())),
+			)
+		} else {
+			plog.Infof("starting server... [version: %v, cluster version: %v]", version.Version, version.Cluster(s.ClusterVersion().String()))
+		}
+		membership.ClusterVersionMetrics.With(prometheus.Labels{"cluster_version": s.ClusterVersion().String()}).Set(1)
+	} else {
+		if lg != nil {
+			lg.Info(
+				"starting etcd server",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("local-server-version", version.Version),
+				zap.String("cluster-version", "to_be_decided"),
+			)
+		} else {
+			plog.Infof("starting server... [version: %v, cluster version: to_be_decided]", version.Version)
+		}
+	}
+
+	// TODO: if this is an empty log, writes all peer infos
+	// into the first entry
+	go s.run()
+}
+
+func (s *EtcdServer) purgeFile() {
+	var dberrc, serrc, werrc <-chan error
+	if s.Cfg.MaxSnapFiles > 0 {
+		dberrc = fileutil.PurgeFile(s.getLogger(), s.Cfg.SnapDir(), "snap.db", s.Cfg.MaxSnapFiles, purgeFileInterval, s.done)
+		serrc = fileutil.PurgeFile(s.getLogger(), s.Cfg.SnapDir(), "snap", s.Cfg.MaxSnapFiles, purgeFileInterval, s.done)
+	}
+	if s.Cfg.MaxWALFiles > 0 {
+		werrc = fileutil.PurgeFile(s.getLogger(), s.Cfg.WALDir(), "wal", s.Cfg.MaxWALFiles, purgeFileInterval, s.done)
+	}
+
+	lg := s.getLogger()
+	select {
+	case e := <-dberrc:
+		if lg != nil {
+			lg.Fatal("failed to purge snap db file", zap.Error(e))
+		} else {
+			plog.Fatalf("failed to purge snap db file %v", e)
+		}
+	case e := <-serrc:
+		if lg != nil {
+			lg.Fatal("failed to purge snap file", zap.Error(e))
+		} else {
+			plog.Fatalf("failed to purge snap file %v", e)
+		}
+	case e := <-werrc:
+		if lg != nil {
+			lg.Fatal("failed to purge wal file", zap.Error(e))
+		} else {
+			plog.Fatalf("failed to purge wal file %v", e)
+		}
+	case <-s.stopping:
+		return
+	}
+}
+
+func (s *EtcdServer) Cluster() api.Cluster { return s.cluster }
+
+func (s *EtcdServer) ApplyWait() <-chan struct{} { return s.applyWait.Wait(s.getCommittedIndex()) }
+
+type ServerPeer interface {
+	ServerV2
+	RaftHandler() http.Handler
+	LeaseHandler() http.Handler
+}
+
+func (s *EtcdServer) LeaseHandler() http.Handler {
+	if s.lessor == nil {
+		return nil
+	}
+	return leasehttp.NewHandler(s.lessor, s.ApplyWait)
+}
+
+func (s *EtcdServer) RaftHandler() http.Handler { return s.r.transport.Handler() }
+
+// Process takes a raft message and applies it to the server's raft state
+// machine, respecting any timeout of the given context.
+func (s *EtcdServer) Process(ctx context.Context, m raftpb.Message) error {
+	if s.cluster.IsIDRemoved(types.ID(m.From)) {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejected Raft message from removed member",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("removed-member-id", types.ID(m.From).String()),
+			)
+		} else {
+			plog.Warningf("reject message from removed member %s", types.ID(m.From).String())
+		}
+		return httptypes.NewHTTPError(http.StatusForbidden, "cannot process message from removed member")
+	}
+	if m.Type == raftpb.MsgApp {
+		s.stats.RecvAppendReq(types.ID(m.From).String(), m.Size())
+	}
+	return s.r.Step(ctx, m)
+}
+
+func (s *EtcdServer) IsIDRemoved(id uint64) bool { return s.cluster.IsIDRemoved(types.ID(id)) }
+
+func (s *EtcdServer) ReportUnreachable(id uint64) { s.r.ReportUnreachable(id) }
+
+// ReportSnapshot reports snapshot sent status to the raft state machine,
+// and clears the used snapshot from the snapshot store.
+func (s *EtcdServer) ReportSnapshot(id uint64, status raft.SnapshotStatus) {
+	s.r.ReportSnapshot(id, status)
+}
+
+type etcdProgress struct {
+	confState raftpb.ConfState
+	snapi     uint64
+	appliedt  uint64
+	appliedi  uint64
+}
+
+// raftReadyHandler contains a set of EtcdServer operations to be called by raftNode,
+// and helps decouple state machine logic from Raft algorithms.
+// TODO: add a state machine interface to apply the commit entries and do snapshot/recover
+type raftReadyHandler struct {
+	getLead              func() (lead uint64)
+	updateLead           func(lead uint64)
+	updateLeadership     func(newLeader bool)
+	updateCommittedIndex func(uint64)
+}
+
+func (s *EtcdServer) run() {
+	lg := s.getLogger()
+
+	sn, err := s.r.raftStorage.Snapshot()
+	if err != nil {
+		if lg != nil {
+			lg.Panic("failed to get snapshot from Raft storage", zap.Error(err))
+		} else {
+			plog.Panicf("get snapshot from raft storage error: %v", err)
+		}
+	}
+
+	// asynchronously accept apply packets, dispatch progress in-order
+	sched := schedule.NewFIFOScheduler()
+
+	var (
+		smu   sync.RWMutex
+		syncC <-chan time.Time
+	)
+	setSyncC := func(ch <-chan time.Time) {
+		smu.Lock()
+		syncC = ch
+		smu.Unlock()
+	}
+	getSyncC := func() (ch <-chan time.Time) {
+		smu.RLock()
+		ch = syncC
+		smu.RUnlock()
+		return
+	}
+	rh := &raftReadyHandler{
+		getLead:    func() (lead uint64) { return s.getLead() },
+		updateLead: func(lead uint64) { s.setLead(lead) },
+		updateLeadership: func(newLeader bool) {
+			if !s.isLeader() {
+				if s.lessor != nil {
+					s.lessor.Demote()
+				}
+				if s.compactor != nil {
+					s.compactor.Pause()
+				}
+				setSyncC(nil)
+			} else {
+				if newLeader {
+					t := time.Now()
+					s.leadTimeMu.Lock()
+					s.leadElectedTime = t
+					s.leadTimeMu.Unlock()
+				}
+				setSyncC(s.SyncTicker.C)
+				if s.compactor != nil {
+					s.compactor.Resume()
+				}
+			}
+			if newLeader {
+				s.leaderChangedMu.Lock()
+				lc := s.leaderChanged
+				s.leaderChanged = make(chan struct{})
+				close(lc)
+				s.leaderChangedMu.Unlock()
+			}
+			// TODO: remove the nil checking
+			// current test utility does not provide the stats
+			if s.stats != nil {
+				s.stats.BecomeLeader()
+			}
+		},
+		updateCommittedIndex: func(ci uint64) {
+			cci := s.getCommittedIndex()
+			if ci > cci {
+				s.setCommittedIndex(ci)
+			}
+		},
+	}
+	s.r.start(rh)
+
+	ep := etcdProgress{
+		confState: sn.Metadata.ConfState,
+		snapi:     sn.Metadata.Index,
+		appliedt:  sn.Metadata.Term,
+		appliedi:  sn.Metadata.Index,
+	}
+
+	defer func() {
+		s.wgMu.Lock() // block concurrent waitgroup adds in goAttach while stopping
+		close(s.stopping)
+		s.wgMu.Unlock()
+		s.cancel()
+
+		sched.Stop()
+
+		// wait for gouroutines before closing raft so wal stays open
+		s.wg.Wait()
+
+		s.SyncTicker.Stop()
+
+		// must stop raft after scheduler-- etcdserver can leak rafthttp pipelines
+		// by adding a peer after raft stops the transport
+		s.r.stop()
+
+		// kv, lessor and backend can be nil if running without v3 enabled
+		// or running unit tests.
+		if s.lessor != nil {
+			s.lessor.Stop()
+		}
+		if s.kv != nil {
+			s.kv.Close()
+		}
+		if s.authStore != nil {
+			s.authStore.Close()
+		}
+		if s.be != nil {
+			s.be.Close()
+		}
+		if s.compactor != nil {
+			s.compactor.Stop()
+		}
+		close(s.done)
+	}()
+
+	var expiredLeaseC <-chan []*lease.Lease
+	if s.lessor != nil {
+		expiredLeaseC = s.lessor.ExpiredLeasesC()
+	}
+
+	for {
+		select {
+		case ap := <-s.r.apply():
+			f := func(context.Context) { s.applyAll(&ep, &ap) }
+			sched.Schedule(f)
+		case leases := <-expiredLeaseC:
+			s.goAttach(func() {
+				// Increases throughput of expired leases deletion process through parallelization
+				c := make(chan struct{}, maxPendingRevokes)
+				for _, lease := range leases {
+					select {
+					case c <- struct{}{}:
+					case <-s.stopping:
+						return
+					}
+					lid := lease.ID
+					s.goAttach(func() {
+						ctx := s.authStore.WithRoot(s.ctx)
+						_, lerr := s.LeaseRevoke(ctx, &pb.LeaseRevokeRequest{ID: int64(lid)})
+						if lerr == nil {
+							leaseExpired.Inc()
+						} else {
+							if lg != nil {
+								lg.Warn(
+									"failed to revoke lease",
+									zap.String("lease-id", fmt.Sprintf("%016x", lid)),
+									zap.Error(lerr),
+								)
+							} else {
+								plog.Warningf("failed to revoke %016x (%q)", lid, lerr.Error())
+							}
+						}
+
+						<-c
+					})
+				}
+			})
+		case err := <-s.errorc:
+			if lg != nil {
+				lg.Warn("server error", zap.Error(err))
+				lg.Warn("data-dir used by this member must be removed")
+			} else {
+				plog.Errorf("%s", err)
+				plog.Infof("the data-dir used by this member must be removed.")
+			}
+			return
+		case <-getSyncC():
+			if s.v2store.HasTTLKeys() {
+				s.sync(s.Cfg.ReqTimeout())
+			}
+		case <-s.stop:
+			return
+		}
+	}
+}
+
+func (s *EtcdServer) applyAll(ep *etcdProgress, apply *apply) {
+	s.applySnapshot(ep, apply)
+	s.applyEntries(ep, apply)
+
+	proposalsApplied.Set(float64(ep.appliedi))
+	s.applyWait.Trigger(ep.appliedi)
+
+	// wait for the raft routine to finish the disk writes before triggering a
+	// snapshot. or applied index might be greater than the last index in raft
+	// storage, since the raft routine might be slower than apply routine.
+	<-apply.notifyc
+
+	s.triggerSnapshot(ep)
+	select {
+	// snapshot requested via send()
+	case m := <-s.r.msgSnapC:
+		merged := s.createMergedSnapshotMessage(m, ep.appliedt, ep.appliedi, ep.confState)
+		s.sendMergedSnap(merged)
+	default:
+	}
+}
+
+func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
+	if raft.IsEmptySnap(apply.snapshot) {
+		return
+	}
+	applySnapshotInProgress.Inc()
+
+	lg := s.getLogger()
+	if lg != nil {
+		lg.Info(
+			"applying snapshot",
+			zap.Uint64("current-snapshot-index", ep.snapi),
+			zap.Uint64("current-applied-index", ep.appliedi),
+			zap.Uint64("incoming-leader-snapshot-index", apply.snapshot.Metadata.Index),
+			zap.Uint64("incoming-leader-snapshot-term", apply.snapshot.Metadata.Term),
+		)
+	} else {
+		plog.Infof("applying snapshot at index %d...", ep.snapi)
+	}
+	defer func() {
+		if lg != nil {
+			lg.Info(
+				"applied snapshot",
+				zap.Uint64("current-snapshot-index", ep.snapi),
+				zap.Uint64("current-applied-index", ep.appliedi),
+				zap.Uint64("incoming-leader-snapshot-index", apply.snapshot.Metadata.Index),
+				zap.Uint64("incoming-leader-snapshot-term", apply.snapshot.Metadata.Term),
+			)
+		} else {
+			plog.Infof("finished applying incoming snapshot at index %d", ep.snapi)
+		}
+		applySnapshotInProgress.Dec()
+	}()
+
+	if apply.snapshot.Metadata.Index <= ep.appliedi {
+		if lg != nil {
+			lg.Panic(
+				"unexpected leader snapshot from outdated index",
+				zap.Uint64("current-snapshot-index", ep.snapi),
+				zap.Uint64("current-applied-index", ep.appliedi),
+				zap.Uint64("incoming-leader-snapshot-index", apply.snapshot.Metadata.Index),
+				zap.Uint64("incoming-leader-snapshot-term", apply.snapshot.Metadata.Term),
+			)
+		} else {
+			plog.Panicf("snapshot index [%d] should > appliedi[%d] + 1",
+				apply.snapshot.Metadata.Index, ep.appliedi)
+		}
+	}
+
+	// wait for raftNode to persist snapshot onto the disk
+	<-apply.notifyc
+
+	newbe, err := openSnapshotBackend(s.Cfg, s.snapshotter, apply.snapshot)
+	if err != nil {
+		if lg != nil {
+			lg.Panic("failed to open snapshot backend", zap.Error(err))
+		} else {
+			plog.Panic(err)
+		}
+	}
+
+	// always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases.
+	// If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers.
+	if s.lessor != nil {
+		if lg != nil {
+			lg.Info("restoring lease store")
+		} else {
+			plog.Info("recovering lessor...")
+		}
+
+		s.lessor.Recover(newbe, func() lease.TxnDelete { return s.kv.Write() })
+
+		if lg != nil {
+			lg.Info("restored lease store")
+		} else {
+			plog.Info("finished recovering lessor")
+		}
+	}
+
+	if lg != nil {
+		lg.Info("restoring mvcc store")
+	} else {
+		plog.Info("restoring mvcc store...")
+	}
+
+	if err := s.kv.Restore(newbe); err != nil {
+		if lg != nil {
+			lg.Panic("failed to restore mvcc store", zap.Error(err))
+		} else {
+			plog.Panicf("restore KV error: %v", err)
+		}
+	}
+
+	s.consistIndex.setConsistentIndex(s.kv.ConsistentIndex())
+	if lg != nil {
+		lg.Info("restored mvcc store")
+	} else {
+		plog.Info("finished restoring mvcc store")
+	}
+
+	// Closing old backend might block until all the txns
+	// on the backend are finished.
+	// We do not want to wait on closing the old backend.
+	s.bemu.Lock()
+	oldbe := s.be
+	go func() {
+		if lg != nil {
+			lg.Info("closing old backend file")
+		} else {
+			plog.Info("closing old backend...")
+		}
+		defer func() {
+			if lg != nil {
+				lg.Info("closed old backend file")
+			} else {
+				plog.Info("finished closing old backend")
+			}
+		}()
+		if err := oldbe.Close(); err != nil {
+			if lg != nil {
+				lg.Panic("failed to close old backend", zap.Error(err))
+			} else {
+				plog.Panicf("close backend error: %v", err)
+			}
+		}
+	}()
+
+	s.be = newbe
+	s.bemu.Unlock()
+
+	if lg != nil {
+		lg.Info("restoring alarm store")
+	} else {
+		plog.Info("recovering alarms...")
+	}
+
+	if err := s.restoreAlarms(); err != nil {
+		if lg != nil {
+			lg.Panic("failed to restore alarm store", zap.Error(err))
+		} else {
+			plog.Panicf("restore alarms error: %v", err)
+		}
+	}
+
+	if lg != nil {
+		lg.Info("restored alarm store")
+	} else {
+		plog.Info("finished recovering alarms")
+	}
+
+	if s.authStore != nil {
+		if lg != nil {
+			lg.Info("restoring auth store")
+		} else {
+			plog.Info("recovering auth store...")
+		}
+
+		s.authStore.Recover(newbe)
+
+		if lg != nil {
+			lg.Info("restored auth store")
+		} else {
+			plog.Info("finished recovering auth store")
+		}
+	}
+
+	if lg != nil {
+		lg.Info("restoring v2 store")
+	} else {
+		plog.Info("recovering store v2...")
+	}
+	if err := s.v2store.Recovery(apply.snapshot.Data); err != nil {
+		if lg != nil {
+			lg.Panic("failed to restore v2 store", zap.Error(err))
+		} else {
+			plog.Panicf("recovery store error: %v", err)
+		}
+	}
+
+	if lg != nil {
+		lg.Info("restored v2 store")
+	} else {
+		plog.Info("finished recovering store v2")
+	}
+
+	s.cluster.SetBackend(newbe)
+
+	if lg != nil {
+		lg.Info("restoring cluster configuration")
+	} else {
+		plog.Info("recovering cluster configuration...")
+	}
+
+	s.cluster.Recover(api.UpdateCapability)
+
+	if lg != nil {
+		lg.Info("restored cluster configuration")
+		lg.Info("removing old peers from network")
+	} else {
+		plog.Info("finished recovering cluster configuration")
+		plog.Info("removing old peers from network...")
+	}
+
+	// recover raft transport
+	s.r.transport.RemoveAllPeers()
+
+	if lg != nil {
+		lg.Info("removed old peers from network")
+		lg.Info("adding peers from new cluster configuration")
+	} else {
+		plog.Info("finished removing old peers from network")
+		plog.Info("adding peers from new cluster configuration into network...")
+	}
+
+	for _, m := range s.cluster.Members() {
+		if m.ID == s.ID() {
+			continue
+		}
+		s.r.transport.AddPeer(m.ID, m.PeerURLs)
+	}
+
+	if lg != nil {
+		lg.Info("added peers from new cluster configuration")
+	} else {
+		plog.Info("finished adding peers from new cluster configuration into network...")
+	}
+
+	ep.appliedt = apply.snapshot.Metadata.Term
+	ep.appliedi = apply.snapshot.Metadata.Index
+	ep.snapi = ep.appliedi
+	ep.confState = apply.snapshot.Metadata.ConfState
+}
+
+func (s *EtcdServer) applyEntries(ep *etcdProgress, apply *apply) {
+	if len(apply.entries) == 0 {
+		return
+	}
+	firsti := apply.entries[0].Index
+	if firsti > ep.appliedi+1 {
+		if lg := s.getLogger(); lg != nil {
+			lg.Panic(
+				"unexpected committed entry index",
+				zap.Uint64("current-applied-index", ep.appliedi),
+				zap.Uint64("first-committed-entry-index", firsti),
+			)
+		} else {
+			plog.Panicf("first index of committed entry[%d] should <= appliedi[%d] + 1", firsti, ep.appliedi)
+		}
+	}
+	var ents []raftpb.Entry
+	if ep.appliedi+1-firsti < uint64(len(apply.entries)) {
+		ents = apply.entries[ep.appliedi+1-firsti:]
+	}
+	if len(ents) == 0 {
+		return
+	}
+	var shouldstop bool
+	if ep.appliedt, ep.appliedi, shouldstop = s.apply(ents, &ep.confState); shouldstop {
+		go s.stopWithDelay(10*100*time.Millisecond, fmt.Errorf("the member has been permanently removed from the cluster"))
+	}
+}
+
+func (s *EtcdServer) triggerSnapshot(ep *etcdProgress) {
+	if ep.appliedi-ep.snapi <= s.Cfg.SnapshotCount {
+		return
+	}
+
+	if lg := s.getLogger(); lg != nil {
+		lg.Info(
+			"triggering snapshot",
+			zap.String("local-member-id", s.ID().String()),
+			zap.Uint64("local-member-applied-index", ep.appliedi),
+			zap.Uint64("local-member-snapshot-index", ep.snapi),
+			zap.Uint64("local-member-snapshot-count", s.Cfg.SnapshotCount),
+		)
+	} else {
+		plog.Infof("start to snapshot (applied: %d, lastsnap: %d)", ep.appliedi, ep.snapi)
+	}
+
+	s.snapshot(ep.appliedi, ep.confState)
+	ep.snapi = ep.appliedi
+}
+
+func (s *EtcdServer) hasMultipleVotingMembers() bool {
+	return s.cluster != nil && len(s.cluster.VotingMemberIDs()) > 1
+}
+
+func (s *EtcdServer) isLeader() bool {
+	return uint64(s.ID()) == s.Lead()
+}
+
+// MoveLeader transfers the leader to the given transferee.
+func (s *EtcdServer) MoveLeader(ctx context.Context, lead, transferee uint64) error {
+	if !s.cluster.IsMemberExist(types.ID(transferee)) || s.cluster.Member(types.ID(transferee)).IsLearner {
+		return ErrBadLeaderTransferee
+	}
+
+	now := time.Now()
+	interval := time.Duration(s.Cfg.TickMs) * time.Millisecond
+
+	if lg := s.getLogger(); lg != nil {
+		lg.Info(
+			"leadership transfer starting",
+			zap.String("local-member-id", s.ID().String()),
+			zap.String("current-leader-member-id", types.ID(lead).String()),
+			zap.String("transferee-member-id", types.ID(transferee).String()),
+		)
+	} else {
+		plog.Infof("%s starts leadership transfer from %s to %s", s.ID(), types.ID(lead), types.ID(transferee))
+	}
+
+	s.r.TransferLeadership(ctx, lead, transferee)
+	for s.Lead() != transferee {
+		select {
+		case <-ctx.Done(): // time out
+			return ErrTimeoutLeaderTransfer
+		case <-time.After(interval):
+		}
+	}
+
+	// TODO: drain all requests, or drop all messages to the old leader
+	if lg := s.getLogger(); lg != nil {
+		lg.Info(
+			"leadership transfer finished",
+			zap.String("local-member-id", s.ID().String()),
+			zap.String("old-leader-member-id", types.ID(lead).String()),
+			zap.String("new-leader-member-id", types.ID(transferee).String()),
+			zap.Duration("took", time.Since(now)),
+		)
+	} else {
+		plog.Infof("%s finished leadership transfer from %s to %s (took %v)", s.ID(), types.ID(lead), types.ID(transferee), time.Since(now))
+	}
+	return nil
+}
+
+// TransferLeadership transfers the leader to the chosen transferee.
+func (s *EtcdServer) TransferLeadership() error {
+	if !s.isLeader() {
+		if lg := s.getLogger(); lg != nil {
+			lg.Info(
+				"skipped leadership transfer; local server is not leader",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("current-leader-member-id", types.ID(s.Lead()).String()),
+			)
+		} else {
+			plog.Printf("skipped leadership transfer for stopping non-leader member")
+		}
+		return nil
+	}
+
+	if !s.hasMultipleVotingMembers() {
+		if lg := s.getLogger(); lg != nil {
+			lg.Info(
+				"skipped leadership transfer for single voting member cluster",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("current-leader-member-id", types.ID(s.Lead()).String()),
+			)
+		} else {
+			plog.Printf("skipped leadership transfer for single voting member cluster")
+		}
+		return nil
+	}
+
+	transferee, ok := longestConnected(s.r.transport, s.cluster.VotingMemberIDs())
+	if !ok {
+		return ErrUnhealthy
+	}
+
+	tm := s.Cfg.ReqTimeout()
+	ctx, cancel := context.WithTimeout(s.ctx, tm)
+	err := s.MoveLeader(ctx, s.Lead(), uint64(transferee))
+	cancel()
+	return err
+}
+
+// HardStop stops the server without coordination with other members in the cluster.
+func (s *EtcdServer) HardStop() {
+	select {
+	case s.stop <- struct{}{}:
+	case <-s.done:
+		return
+	}
+	<-s.done
+}
+
+// Stop stops the server gracefully, and shuts down the running goroutine.
+// Stop should be called after a Start(s), otherwise it will block forever.
+// When stopping leader, Stop transfers its leadership to one of its peers
+// before stopping the server.
+// Stop terminates the Server and performs any necessary finalization.
+// Do and Process cannot be called after Stop has been invoked.
+func (s *EtcdServer) Stop() {
+	if err := s.TransferLeadership(); err != nil {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn("leadership transfer failed", zap.String("local-member-id", s.ID().String()), zap.Error(err))
+		} else {
+			plog.Warningf("%s failed to transfer leadership (%v)", s.ID(), err)
+		}
+	}
+	s.HardStop()
+}
+
+// ReadyNotify returns a channel that will be closed when the server
+// is ready to serve client requests
+func (s *EtcdServer) ReadyNotify() <-chan struct{} { return s.readych }
+
+func (s *EtcdServer) stopWithDelay(d time.Duration, err error) {
+	select {
+	case <-time.After(d):
+	case <-s.done:
+	}
+	select {
+	case s.errorc <- err:
+	default:
+	}
+}
+
+// StopNotify returns a channel that receives a empty struct
+// when the server is stopped.
+func (s *EtcdServer) StopNotify() <-chan struct{} { return s.done }
+
+func (s *EtcdServer) SelfStats() []byte { return s.stats.JSON() }
+
+func (s *EtcdServer) LeaderStats() []byte {
+	lead := s.getLead()
+	if lead != uint64(s.id) {
+		return nil
+	}
+	return s.lstats.JSON()
+}
+
+func (s *EtcdServer) StoreStats() []byte { return s.v2store.JsonStats() }
+
+func (s *EtcdServer) checkMembershipOperationPermission(ctx context.Context) error {
+	if s.authStore == nil {
+		// In the context of ordinary etcd process, s.authStore will never be nil.
+		// This branch is for handling cases in server_test.go
+		return nil
+	}
+
+	// Note that this permission check is done in the API layer,
+	// so TOCTOU problem can be caused potentially in a schedule like this:
+	// update membership with user A -> revoke root role of A -> apply membership change
+	// in the state machine layer
+	// However, both of membership change and role management requires the root privilege.
+	// So careful operation by admins can prevent the problem.
+	authInfo, err := s.AuthInfoFromCtx(ctx)
+	if err != nil {
+		return err
+	}
+
+	return s.AuthStore().IsAdminPermitted(authInfo)
+}
+
+func (s *EtcdServer) AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) {
+	if err := s.checkMembershipOperationPermission(ctx); err != nil {
+		return nil, err
+	}
+
+	// TODO: move Member to protobuf type
+	b, err := json.Marshal(memb)
+	if err != nil {
+		return nil, err
+	}
+
+	// by default StrictReconfigCheck is enabled; reject new members if unhealthy.
+	if err := s.mayAddMember(memb); err != nil {
+		return nil, err
+	}
+
+	cc := raftpb.ConfChange{
+		Type:    raftpb.ConfChangeAddNode,
+		NodeID:  uint64(memb.ID),
+		Context: b,
+	}
+
+	if memb.IsLearner {
+		cc.Type = raftpb.ConfChangeAddLearnerNode
+	}
+
+	return s.configure(ctx, cc)
+}
+
+func (s *EtcdServer) mayAddMember(memb membership.Member) error {
+	if !s.Cfg.StrictReconfigCheck {
+		return nil
+	}
+
+	// protect quorum when adding voting member
+	if !memb.IsLearner && !s.cluster.IsReadyToAddVotingMember() {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejecting member add request; not enough healthy members",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("requested-member-add", fmt.Sprintf("%+v", memb)),
+				zap.Error(ErrNotEnoughStartedMembers),
+			)
+		} else {
+			plog.Warningf("not enough started members, rejecting member add %+v", memb)
+		}
+		return ErrNotEnoughStartedMembers
+	}
+
+	if !isConnectedFullySince(s.r.transport, time.Now().Add(-HealthInterval), s.ID(), s.cluster.VotingMembers()) {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejecting member add request; local member has not been connected to all peers, reconfigure breaks active quorum",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("requested-member-add", fmt.Sprintf("%+v", memb)),
+				zap.Error(ErrUnhealthy),
+			)
+		} else {
+			plog.Warningf("not healthy for reconfigure, rejecting member add %+v", memb)
+		}
+		return ErrUnhealthy
+	}
+
+	return nil
+}
+
+func (s *EtcdServer) RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error) {
+	if err := s.checkMembershipOperationPermission(ctx); err != nil {
+		return nil, err
+	}
+
+	// by default StrictReconfigCheck is enabled; reject removal if leads to quorum loss
+	if err := s.mayRemoveMember(types.ID(id)); err != nil {
+		return nil, err
+	}
+
+	cc := raftpb.ConfChange{
+		Type:   raftpb.ConfChangeRemoveNode,
+		NodeID: id,
+	}
+	return s.configure(ctx, cc)
+}
+
+// PromoteMember promotes a learner node to a voting node.
+func (s *EtcdServer) PromoteMember(ctx context.Context, id uint64) ([]*membership.Member, error) {
+	// only raft leader has information on whether the to-be-promoted learner node is ready. If promoteMember call
+	// fails with ErrNotLeader, forward the request to leader node via HTTP. If promoteMember call fails with error
+	// other than ErrNotLeader, return the error.
+	resp, err := s.promoteMember(ctx, id)
+	if err == nil {
+		learnerPromoteSucceed.Inc()
+		return resp, nil
+	}
+	if err != ErrNotLeader {
+		learnerPromoteFailed.WithLabelValues(err.Error()).Inc()
+		return resp, err
+	}
+
+	cctx, cancel := context.WithTimeout(ctx, s.Cfg.ReqTimeout())
+	defer cancel()
+	// forward to leader
+	for cctx.Err() == nil {
+		leader, err := s.waitLeader(cctx)
+		if err != nil {
+			return nil, err
+		}
+		for _, url := range leader.PeerURLs {
+			resp, err := promoteMemberHTTP(cctx, url, id, s.peerRt)
+			if err == nil {
+				return resp, nil
+			}
+			// If member promotion failed, return early. Otherwise keep retry.
+			if err == ErrLearnerNotReady || err == membership.ErrIDNotFound || err == membership.ErrMemberNotLearner {
+				return nil, err
+			}
+		}
+	}
+
+	if cctx.Err() == context.DeadlineExceeded {
+		return nil, ErrTimeout
+	}
+	return nil, ErrCanceled
+}
+
+// promoteMember checks whether the to-be-promoted learner node is ready before sending the promote
+// request to raft.
+// The function returns ErrNotLeader if the local node is not raft leader (therefore does not have
+// enough information to determine if the learner node is ready), returns ErrLearnerNotReady if the
+// local node is leader (therefore has enough information) but decided the learner node is not ready
+// to be promoted.
+func (s *EtcdServer) promoteMember(ctx context.Context, id uint64) ([]*membership.Member, error) {
+	if err := s.checkMembershipOperationPermission(ctx); err != nil {
+		return nil, err
+	}
+
+	// check if we can promote this learner.
+	if err := s.mayPromoteMember(types.ID(id)); err != nil {
+		return nil, err
+	}
+
+	// build the context for the promote confChange. mark IsLearner to false and IsPromote to true.
+	promoteChangeContext := membership.ConfigChangeContext{
+		Member: membership.Member{
+			ID: types.ID(id),
+		},
+		IsPromote: true,
+	}
+
+	b, err := json.Marshal(promoteChangeContext)
+	if err != nil {
+		return nil, err
+	}
+
+	cc := raftpb.ConfChange{
+		Type:    raftpb.ConfChangeAddNode,
+		NodeID:  id,
+		Context: b,
+	}
+
+	return s.configure(ctx, cc)
+}
+
+func (s *EtcdServer) mayPromoteMember(id types.ID) error {
+	err := s.isLearnerReady(uint64(id))
+	if err != nil {
+		return err
+	}
+
+	if !s.Cfg.StrictReconfigCheck {
+		return nil
+	}
+	if !s.cluster.IsReadyToPromoteMember(uint64(id)) {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejecting member promote request; not enough healthy members",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("requested-member-remove-id", id.String()),
+				zap.Error(ErrNotEnoughStartedMembers),
+			)
+		} else {
+			plog.Warningf("not enough started members, rejecting promote member %s", id)
+		}
+		return ErrNotEnoughStartedMembers
+	}
+
+	return nil
+}
+
+// check whether the learner catches up with leader or not.
+// Note: it will return nil if member is not found in cluster or if member is not learner.
+// These two conditions will be checked before apply phase later.
+func (s *EtcdServer) isLearnerReady(id uint64) error {
+	rs := s.raftStatus()
+
+	// leader's raftStatus.Progress is not nil
+	if rs.Progress == nil {
+		return ErrNotLeader
+	}
+
+	var learnerMatch uint64
+	isFound := false
+	leaderID := rs.ID
+	for memberID, progress := range rs.Progress {
+		if id == memberID {
+			// check its status
+			learnerMatch = progress.Match
+			isFound = true
+			break
+		}
+	}
+
+	if isFound {
+		leaderMatch := rs.Progress[leaderID].Match
+		// the learner's Match not caught up with leader yet
+		if float64(learnerMatch) < float64(leaderMatch)*readyPercent {
+			return ErrLearnerNotReady
+		}
+	}
+
+	return nil
+}
+
+func (s *EtcdServer) mayRemoveMember(id types.ID) error {
+	if !s.Cfg.StrictReconfigCheck {
+		return nil
+	}
+
+	isLearner := s.cluster.IsMemberExist(id) && s.cluster.Member(id).IsLearner
+	// no need to check quorum when removing non-voting member
+	if isLearner {
+		return nil
+	}
+
+	if !s.cluster.IsReadyToRemoveVotingMember(uint64(id)) {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejecting member remove request; not enough healthy members",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("requested-member-remove-id", id.String()),
+				zap.Error(ErrNotEnoughStartedMembers),
+			)
+		} else {
+			plog.Warningf("not enough started members, rejecting remove member %s", id)
+		}
+		return ErrNotEnoughStartedMembers
+	}
+
+	// downed member is safe to remove since it's not part of the active quorum
+	if t := s.r.transport.ActiveSince(id); id != s.ID() && t.IsZero() {
+		return nil
+	}
+
+	// protect quorum if some members are down
+	m := s.cluster.VotingMembers()
+	active := numConnectedSince(s.r.transport, time.Now().Add(-HealthInterval), s.ID(), m)
+	if (active - 1) < 1+((len(m)-1)/2) {
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn(
+				"rejecting member remove request; local member has not been connected to all peers, reconfigure breaks active quorum",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("requested-member-remove", id.String()),
+				zap.Int("active-peers", active),
+				zap.Error(ErrUnhealthy),
+			)
+		} else {
+			plog.Warningf("reconfigure breaks active quorum, rejecting remove member %s", id)
+		}
+		return ErrUnhealthy
+	}
+
+	return nil
+}
+
+func (s *EtcdServer) UpdateMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) {
+	b, merr := json.Marshal(memb)
+	if merr != nil {
+		return nil, merr
+	}
+
+	if err := s.checkMembershipOperationPermission(ctx); err != nil {
+		return nil, err
+	}
+	cc := raftpb.ConfChange{
+		Type:    raftpb.ConfChangeUpdateNode,
+		NodeID:  uint64(memb.ID),
+		Context: b,
+	}
+	return s.configure(ctx, cc)
+}
+
+func (s *EtcdServer) setCommittedIndex(v uint64) {
+	atomic.StoreUint64(&s.committedIndex, v)
+}
+
+func (s *EtcdServer) getCommittedIndex() uint64 {
+	return atomic.LoadUint64(&s.committedIndex)
+}
+
+func (s *EtcdServer) setAppliedIndex(v uint64) {
+	atomic.StoreUint64(&s.appliedIndex, v)
+}
+
+func (s *EtcdServer) getAppliedIndex() uint64 {
+	return atomic.LoadUint64(&s.appliedIndex)
+}
+
+func (s *EtcdServer) setTerm(v uint64) {
+	atomic.StoreUint64(&s.term, v)
+}
+
+func (s *EtcdServer) getTerm() uint64 {
+	return atomic.LoadUint64(&s.term)
+}
+
+func (s *EtcdServer) setLead(v uint64) {
+	atomic.StoreUint64(&s.lead, v)
+}
+
+func (s *EtcdServer) getLead() uint64 {
+	return atomic.LoadUint64(&s.lead)
+}
+
+func (s *EtcdServer) leaderChangedNotify() <-chan struct{} {
+	s.leaderChangedMu.RLock()
+	defer s.leaderChangedMu.RUnlock()
+	return s.leaderChanged
+}
+
+// RaftStatusGetter represents etcd server and Raft progress.
+type RaftStatusGetter interface {
+	ID() types.ID
+	Leader() types.ID
+	CommittedIndex() uint64
+	AppliedIndex() uint64
+	Term() uint64
+}
+
+func (s *EtcdServer) ID() types.ID { return s.id }
+
+func (s *EtcdServer) Leader() types.ID { return types.ID(s.getLead()) }
+
+func (s *EtcdServer) Lead() uint64 { return s.getLead() }
+
+func (s *EtcdServer) CommittedIndex() uint64 { return s.getCommittedIndex() }
+
+func (s *EtcdServer) AppliedIndex() uint64 { return s.getAppliedIndex() }
+
+func (s *EtcdServer) Term() uint64 { return s.getTerm() }
+
+type confChangeResponse struct {
+	membs []*membership.Member
+	err   error
+}
+
+// configure sends a configuration change through consensus and
+// then waits for it to be applied to the server. It
+// will block until the change is performed or there is an error.
+func (s *EtcdServer) configure(ctx context.Context, cc raftpb.ConfChange) ([]*membership.Member, error) {
+	cc.ID = s.reqIDGen.Next()
+	ch := s.w.Register(cc.ID)
+
+	start := time.Now()
+	if err := s.r.ProposeConfChange(ctx, cc); err != nil {
+		s.w.Trigger(cc.ID, nil)
+		return nil, err
+	}
+
+	select {
+	case x := <-ch:
+		if x == nil {
+			if lg := s.getLogger(); lg != nil {
+				lg.Panic("failed to configure")
+			} else {
+				plog.Panicf("configure trigger value should never be nil")
+			}
+		}
+		resp := x.(*confChangeResponse)
+		if lg := s.getLogger(); lg != nil {
+			lg.Info(
+				"applied a configuration change through raft",
+				zap.String("local-member-id", s.ID().String()),
+				zap.String("raft-conf-change", cc.Type.String()),
+				zap.String("raft-conf-change-node-id", types.ID(cc.NodeID).String()),
+			)
+		}
+		return resp.membs, resp.err
+
+	case <-ctx.Done():
+		s.w.Trigger(cc.ID, nil) // GC wait
+		return nil, s.parseProposeCtxErr(ctx.Err(), start)
+
+	case <-s.stopping:
+		return nil, ErrStopped
+	}
+}
+
+// sync proposes a SYNC request and is non-blocking.
+// This makes no guarantee that the request will be proposed or performed.
+// The request will be canceled after the given timeout.
+func (s *EtcdServer) sync(timeout time.Duration) {
+	req := pb.Request{
+		Method: "SYNC",
+		ID:     s.reqIDGen.Next(),
+		Time:   time.Now().UnixNano(),
+	}
+	data := pbutil.MustMarshal(&req)
+	// There is no promise that node has leader when do SYNC request,
+	// so it uses goroutine to propose.
+	ctx, cancel := context.WithTimeout(s.ctx, timeout)
+	s.goAttach(func() {
+		s.r.Propose(ctx, data)
+		cancel()
+	})
+}
+
+// publish registers server information into the cluster. The information
+// is the JSON representation of this server's member struct, updated with the
+// static clientURLs of the server.
+// The function keeps attempting to register until it succeeds,
+// or its server is stopped.
+//
+// Use v2 store to encode member attributes, and apply through Raft
+// but does not go through v2 API endpoint, which means even with v2
+// client handler disabled (e.g. --enable-v2=false), cluster can still
+// process publish requests through rafthttp
+// TODO: Deprecate v2 store
+func (s *EtcdServer) publish(timeout time.Duration) {
+	b, err := json.Marshal(s.attributes)
+	if err != nil {
+		if lg := s.getLogger(); lg != nil {
+			lg.Panic("failed to marshal JSON", zap.Error(err))
+		} else {
+			plog.Panicf("json marshal error: %v", err)
+		}
+		return
+	}
+	req := pb.Request{
+		Method: "PUT",
+		Path:   membership.MemberAttributesStorePath(s.id),
+		Val:    string(b),
+	}
+
+	for {
+		ctx, cancel := context.WithTimeout(s.ctx, timeout)
+		_, err := s.Do(ctx, req)
+		cancel()
+		switch err {
+		case nil:
+			close(s.readych)
+			if lg := s.getLogger(); lg != nil {
+				lg.Info(
+					"published local member to cluster through raft",
+					zap.String("local-member-id", s.ID().String()),
+					zap.String("local-member-attributes", fmt.Sprintf("%+v", s.attributes)),
+					zap.String("request-path", req.Path),
+					zap.String("cluster-id", s.cluster.ID().String()),
+					zap.Duration("publish-timeout", timeout),
+				)
+			} else {
+				plog.Infof("published %+v to cluster %s", s.attributes, s.cluster.ID())
+			}
+			return
+
+		case ErrStopped:
+			if lg := s.getLogger(); lg != nil {
+				lg.Warn(
+					"stopped publish because server is stopped",
+					zap.String("local-member-id", s.ID().String()),
+					zap.String("local-member-attributes", fmt.Sprintf("%+v", s.attributes)),
+					zap.Duration("publish-timeout", timeout),
+					zap.Error(err),
+				)
+			} else {
+				plog.Infof("aborting publish because server is stopped")
+			}
+			return
+
+		default:
+			if lg := s.getLogger(); lg != nil {
+				lg.Warn(
+					"failed to publish local member to cluster through raft",
+					zap.String("local-member-id", s.ID().String()),
+					zap.String("local-member-attributes", fmt.Sprintf("%+v", s.attributes)),
+					zap.String("request-path", req.Path),
+					zap.Duration("publish-timeout", timeout),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("publish error: %v", err)
+			}
+		}
+	}
+}
+
+func (s *EtcdServer) sendMergedSnap(merged snap.Message) {
+	atomic.AddInt64(&s.inflightSnapshots, 1)
+
+	lg := s.getLogger()
+	fields := []zap.Field{
+		zap.String("from", s.ID().String()),
+		zap.String("to", types.ID(merged.To).String()),
+		zap.Int64("bytes", merged.TotalSize),
+		zap.String("size", humanize.Bytes(uint64(merged.TotalSize))),
+	}
+
+	now := time.Now()
+	s.r.transport.SendSnapshot(merged)
+	if lg != nil {
+		lg.Info("sending merged snapshot", fields...)
+	}
+
+	s.goAttach(func() {
+		select {
+		case ok := <-merged.CloseNotify():
+			// delay releasing inflight snapshot for another 30 seconds to
+			// block log compaction.
+			// If the follower still fails to catch up, it is probably just too slow
+			// to catch up. We cannot avoid the snapshot cycle anyway.
+			if ok {
+				select {
+				case <-time.After(releaseDelayAfterSnapshot):
+				case <-s.stopping:
+				}
+			}
+
+			atomic.AddInt64(&s.inflightSnapshots, -1)
+
+			if lg != nil {
+				lg.Info("sent merged snapshot", append(fields, zap.Duration("took", time.Since(now)))...)
+			}
+
+		case <-s.stopping:
+			if lg != nil {
+				lg.Warn("canceled sending merged snapshot; server stopping", fields...)
+			}
+			return
+		}
+	})
+}
+
+// apply takes entries received from Raft (after it has been committed) and
+// applies them to the current state of the EtcdServer.
+// The given entries should not be empty.
+func (s *EtcdServer) apply(
+	es []raftpb.Entry,
+	confState *raftpb.ConfState,
+) (appliedt uint64, appliedi uint64, shouldStop bool) {
+	for i := range es {
+		e := es[i]
+		switch e.Type {
+		case raftpb.EntryNormal:
+			s.applyEntryNormal(&e)
+			s.setAppliedIndex(e.Index)
+			s.setTerm(e.Term)
+
+		case raftpb.EntryConfChange:
+			// set the consistent index of current executing entry
+			if e.Index > s.consistIndex.ConsistentIndex() {
+				s.consistIndex.setConsistentIndex(e.Index)
+			}
+			var cc raftpb.ConfChange
+			pbutil.MustUnmarshal(&cc, e.Data)
+			removedSelf, err := s.applyConfChange(cc, confState)
+			s.setAppliedIndex(e.Index)
+			s.setTerm(e.Term)
+			shouldStop = shouldStop || removedSelf
+			s.w.Trigger(cc.ID, &confChangeResponse{s.cluster.Members(), err})
+
+		default:
+			if lg := s.getLogger(); lg != nil {
+				lg.Panic(
+					"unknown entry type; must be either EntryNormal or EntryConfChange",
+					zap.String("type", e.Type.String()),
+				)
+			} else {
+				plog.Panicf("entry type should be either EntryNormal or EntryConfChange")
+			}
+		}
+		appliedi, appliedt = e.Index, e.Term
+	}
+	return appliedt, appliedi, shouldStop
+}
+
+// applyEntryNormal apples an EntryNormal type raftpb request to the EtcdServer
+func (s *EtcdServer) applyEntryNormal(e *raftpb.Entry) {
+	shouldApplyV3 := false
+	if e.Index > s.consistIndex.ConsistentIndex() {
+		// set the consistent index of current executing entry
+		s.consistIndex.setConsistentIndex(e.Index)
+		shouldApplyV3 = true
+	}
+
+	// raft state machine may generate noop entry when leader confirmation.
+	// skip it in advance to avoid some potential bug in the future
+	if len(e.Data) == 0 {
+		select {
+		case s.forceVersionC <- struct{}{}:
+		default:
+		}
+		// promote lessor when the local member is leader and finished
+		// applying all entries from the last term.
+		if s.isLeader() {
+			s.lessor.Promote(s.Cfg.electionTimeout())
+		}
+		return
+	}
+
+	var raftReq pb.InternalRaftRequest
+	if !pbutil.MaybeUnmarshal(&raftReq, e.Data) { // backward compatible
+		var r pb.Request
+		rp := &r
+		pbutil.MustUnmarshal(rp, e.Data)
+		s.w.Trigger(r.ID, s.applyV2Request((*RequestV2)(rp)))
+		return
+	}
+	if raftReq.V2 != nil {
+		req := (*RequestV2)(raftReq.V2)
+		s.w.Trigger(req.ID, s.applyV2Request(req))
+		return
+	}
+
+	// do not re-apply applied entries.
+	if !shouldApplyV3 {
+		return
+	}
+
+	id := raftReq.ID
+	if id == 0 {
+		id = raftReq.Header.ID
+	}
+
+	var ar *applyResult
+	needResult := s.w.IsRegistered(id)
+	if needResult || !noSideEffect(&raftReq) {
+		if !needResult && raftReq.Txn != nil {
+			removeNeedlessRangeReqs(raftReq.Txn)
+		}
+		ar = s.applyV3.Apply(&raftReq)
+	}
+
+	if ar == nil {
+		return
+	}
+
+	if ar.err != ErrNoSpace || len(s.alarmStore.Get(pb.AlarmType_NOSPACE)) > 0 {
+		s.w.Trigger(id, ar)
+		return
+	}
+
+	if lg := s.getLogger(); lg != nil {
+		lg.Warn(
+			"message exceeded backend quota; raising alarm",
+			zap.Int64("quota-size-bytes", s.Cfg.QuotaBackendBytes),
+			zap.String("quota-size", humanize.Bytes(uint64(s.Cfg.QuotaBackendBytes))),
+			zap.Error(ar.err),
+		)
+	} else {
+		plog.Errorf("applying raft message exceeded backend quota")
+	}
+
+	s.goAttach(func() {
+		a := &pb.AlarmRequest{
+			MemberID: uint64(s.ID()),
+			Action:   pb.AlarmRequest_ACTIVATE,
+			Alarm:    pb.AlarmType_NOSPACE,
+		}
+		s.raftRequest(s.ctx, pb.InternalRaftRequest{Alarm: a})
+		s.w.Trigger(id, ar)
+	})
+}
+
+// applyConfChange applies a ConfChange to the server. It is only
+// invoked with a ConfChange that has already passed through Raft
+func (s *EtcdServer) applyConfChange(cc raftpb.ConfChange, confState *raftpb.ConfState) (bool, error) {
+	if err := s.cluster.ValidateConfigurationChange(cc); err != nil {
+		cc.NodeID = raft.None
+		s.r.ApplyConfChange(cc)
+		return false, err
+	}
+
+	lg := s.getLogger()
+	*confState = *s.r.ApplyConfChange(cc)
+	switch cc.Type {
+	case raftpb.ConfChangeAddNode, raftpb.ConfChangeAddLearnerNode:
+		confChangeContext := new(membership.ConfigChangeContext)
+		if err := json.Unmarshal(cc.Context, confChangeContext); err != nil {
+			if lg != nil {
+				lg.Panic("failed to unmarshal member", zap.Error(err))
+			} else {
+				plog.Panicf("unmarshal member should never fail: %v", err)
+			}
+		}
+		if cc.NodeID != uint64(confChangeContext.Member.ID) {
+			if lg != nil {
+				lg.Panic(
+					"got different member ID",
+					zap.String("member-id-from-config-change-entry", types.ID(cc.NodeID).String()),
+					zap.String("member-id-from-message", confChangeContext.Member.ID.String()),
+				)
+			} else {
+				plog.Panicf("nodeID should always be equal to member ID")
+			}
+		}
+		if confChangeContext.IsPromote {
+			s.cluster.PromoteMember(confChangeContext.Member.ID)
+		} else {
+			s.cluster.AddMember(&confChangeContext.Member)
+
+			if confChangeContext.Member.ID != s.id {
+				s.r.transport.AddPeer(confChangeContext.Member.ID, confChangeContext.PeerURLs)
+			}
+		}
+
+		// update the isLearner metric when this server id is equal to the id in raft member confChange
+		if confChangeContext.Member.ID == s.id {
+			if cc.Type == raftpb.ConfChangeAddLearnerNode {
+				isLearner.Set(1)
+			} else {
+				isLearner.Set(0)
+			}
+		}
+
+	case raftpb.ConfChangeRemoveNode:
+		id := types.ID(cc.NodeID)
+		s.cluster.RemoveMember(id)
+		if id == s.id {
+			return true, nil
+		}
+		s.r.transport.RemovePeer(id)
+
+	case raftpb.ConfChangeUpdateNode:
+		m := new(membership.Member)
+		if err := json.Unmarshal(cc.Context, m); err != nil {
+			if lg != nil {
+				lg.Panic("failed to unmarshal member", zap.Error(err))
+			} else {
+				plog.Panicf("unmarshal member should never fail: %v", err)
+			}
+		}
+		if cc.NodeID != uint64(m.ID) {
+			if lg != nil {
+				lg.Panic(
+					"got different member ID",
+					zap.String("member-id-from-config-change-entry", types.ID(cc.NodeID).String()),
+					zap.String("member-id-from-message", m.ID.String()),
+				)
+			} else {
+				plog.Panicf("nodeID should always be equal to member ID")
+			}
+		}
+		s.cluster.UpdateRaftAttributes(m.ID, m.RaftAttributes)
+		if m.ID != s.id {
+			s.r.transport.UpdatePeer(m.ID, m.PeerURLs)
+		}
+	}
+	return false, nil
+}
+
+// TODO: non-blocking snapshot
+func (s *EtcdServer) snapshot(snapi uint64, confState raftpb.ConfState) {
+	clone := s.v2store.Clone()
+	// commit kv to write metadata (for example: consistent index) to disk.
+	// KV().commit() updates the consistent index in backend.
+	// All operations that update consistent index must be called sequentially
+	// from applyAll function.
+	// So KV().Commit() cannot run in parallel with apply. It has to be called outside
+	// the go routine created below.
+	s.KV().Commit()
+
+	s.goAttach(func() {
+		lg := s.getLogger()
+
+		d, err := clone.SaveNoCopy()
+		// TODO: current store will never fail to do a snapshot
+		// what should we do if the store might fail?
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to save v2 store", zap.Error(err))
+			} else {
+				plog.Panicf("store save should never fail: %v", err)
+			}
+		}
+		snap, err := s.r.raftStorage.CreateSnapshot(snapi, &confState, d)
+		if err != nil {
+			// the snapshot was done asynchronously with the progress of raft.
+			// raft might have already got a newer snapshot.
+			if err == raft.ErrSnapOutOfDate {
+				return
+			}
+			if lg != nil {
+				lg.Panic("failed to create snapshot", zap.Error(err))
+			} else {
+				plog.Panicf("unexpected create snapshot error %v", err)
+			}
+		}
+		// SaveSnap saves the snapshot and releases the locked wal files
+		// to the snapshot index.
+		if err = s.r.storage.SaveSnap(snap); err != nil {
+			if lg != nil {
+				lg.Panic("failed to save snapshot", zap.Error(err))
+			} else {
+				plog.Fatalf("save snapshot error: %v", err)
+			}
+		}
+		if lg != nil {
+			lg.Info(
+				"saved snapshot",
+				zap.Uint64("snapshot-index", snap.Metadata.Index),
+			)
+		} else {
+			plog.Infof("saved snapshot at index %d", snap.Metadata.Index)
+		}
+
+		// When sending a snapshot, etcd will pause compaction.
+		// After receives a snapshot, the slow follower needs to get all the entries right after
+		// the snapshot sent to catch up. If we do not pause compaction, the log entries right after
+		// the snapshot sent might already be compacted. It happens when the snapshot takes long time
+		// to send and save. Pausing compaction avoids triggering a snapshot sending cycle.
+		if atomic.LoadInt64(&s.inflightSnapshots) != 0 {
+			if lg != nil {
+				lg.Info("skip compaction since there is an inflight snapshot")
+			} else {
+				plog.Infof("skip compaction since there is an inflight snapshot")
+			}
+			return
+		}
+
+		// keep some in memory log entries for slow followers.
+		compacti := uint64(1)
+		if snapi > s.Cfg.SnapshotCatchUpEntries {
+			compacti = snapi - s.Cfg.SnapshotCatchUpEntries
+		}
+
+		err = s.r.raftStorage.Compact(compacti)
+		if err != nil {
+			// the compaction was done asynchronously with the progress of raft.
+			// raft log might already been compact.
+			if err == raft.ErrCompacted {
+				return
+			}
+			if lg != nil {
+				lg.Panic("failed to compact", zap.Error(err))
+			} else {
+				plog.Panicf("unexpected compaction error %v", err)
+			}
+		}
+		if lg != nil {
+			lg.Info(
+				"compacted Raft logs",
+				zap.Uint64("compact-index", compacti),
+			)
+		} else {
+			plog.Infof("compacted raft log at %d", compacti)
+		}
+	})
+}
+
+// CutPeer drops messages to the specified peer.
+func (s *EtcdServer) CutPeer(id types.ID) {
+	tr, ok := s.r.transport.(*rafthttp.Transport)
+	if ok {
+		tr.CutPeer(id)
+	}
+}
+
+// MendPeer recovers the message dropping behavior of the given peer.
+func (s *EtcdServer) MendPeer(id types.ID) {
+	tr, ok := s.r.transport.(*rafthttp.Transport)
+	if ok {
+		tr.MendPeer(id)
+	}
+}
+
+func (s *EtcdServer) PauseSending() { s.r.pauseSending() }
+
+func (s *EtcdServer) ResumeSending() { s.r.resumeSending() }
+
+func (s *EtcdServer) ClusterVersion() *semver.Version {
+	if s.cluster == nil {
+		return nil
+	}
+	return s.cluster.Version()
+}
+
+// monitorVersions checks the member's version every monitorVersionInterval.
+// It updates the cluster version if all members agrees on a higher one.
+// It prints out log if there is a member with a higher version than the
+// local version.
+func (s *EtcdServer) monitorVersions() {
+	for {
+		select {
+		case <-s.forceVersionC:
+		case <-time.After(monitorVersionInterval):
+		case <-s.stopping:
+			return
+		}
+
+		if s.Leader() != s.ID() {
+			continue
+		}
+
+		v := decideClusterVersion(s.getLogger(), getVersions(s.getLogger(), s.cluster, s.id, s.peerRt))
+		if v != nil {
+			// only keep major.minor version for comparison
+			v = &semver.Version{
+				Major: v.Major,
+				Minor: v.Minor,
+			}
+		}
+
+		// if the current version is nil:
+		// 1. use the decided version if possible
+		// 2. or use the min cluster version
+		if s.cluster.Version() == nil {
+			verStr := version.MinClusterVersion
+			if v != nil {
+				verStr = v.String()
+			}
+			s.goAttach(func() { s.updateClusterVersion(verStr) })
+			continue
+		}
+
+		// update cluster version only if the decided version is greater than
+		// the current cluster version
+		if v != nil && s.cluster.Version().LessThan(*v) {
+			s.goAttach(func() { s.updateClusterVersion(v.String()) })
+		}
+	}
+}
+
+func (s *EtcdServer) updateClusterVersion(ver string) {
+	lg := s.getLogger()
+
+	if s.cluster.Version() == nil {
+		if lg != nil {
+			lg.Info(
+				"setting up initial cluster version",
+				zap.String("cluster-version", version.Cluster(ver)),
+			)
+		} else {
+			plog.Infof("setting up the initial cluster version to %s", version.Cluster(ver))
+		}
+	} else {
+		if lg != nil {
+			lg.Info(
+				"updating cluster version",
+				zap.String("from", version.Cluster(s.cluster.Version().String())),
+				zap.String("to", version.Cluster(ver)),
+			)
+		} else {
+			plog.Infof("updating the cluster version from %s to %s", version.Cluster(s.cluster.Version().String()), version.Cluster(ver))
+		}
+	}
+
+	req := pb.Request{
+		Method: "PUT",
+		Path:   membership.StoreClusterVersionKey(),
+		Val:    ver,
+	}
+
+	ctx, cancel := context.WithTimeout(s.ctx, s.Cfg.ReqTimeout())
+	_, err := s.Do(ctx, req)
+	cancel()
+
+	switch err {
+	case nil:
+		if lg != nil {
+			lg.Info("cluster version is updated", zap.String("cluster-version", version.Cluster(ver)))
+		}
+		return
+
+	case ErrStopped:
+		if lg != nil {
+			lg.Warn("aborting cluster version update; server is stopped", zap.Error(err))
+		} else {
+			plog.Infof("aborting update cluster version because server is stopped")
+		}
+		return
+
+	default:
+		if lg != nil {
+			lg.Warn("failed to update cluster version", zap.Error(err))
+		} else {
+			plog.Errorf("error updating cluster version (%v)", err)
+		}
+	}
+}
+
+func (s *EtcdServer) parseProposeCtxErr(err error, start time.Time) error {
+	switch err {
+	case context.Canceled:
+		return ErrCanceled
+
+	case context.DeadlineExceeded:
+		s.leadTimeMu.RLock()
+		curLeadElected := s.leadElectedTime
+		s.leadTimeMu.RUnlock()
+		prevLeadLost := curLeadElected.Add(-2 * time.Duration(s.Cfg.ElectionTicks) * time.Duration(s.Cfg.TickMs) * time.Millisecond)
+		if start.After(prevLeadLost) && start.Before(curLeadElected) {
+			return ErrTimeoutDueToLeaderFail
+		}
+		lead := types.ID(s.getLead())
+		switch lead {
+		case types.ID(raft.None):
+			// TODO: return error to specify it happens because the cluster does not have leader now
+		case s.ID():
+			if !isConnectedToQuorumSince(s.r.transport, start, s.ID(), s.cluster.Members()) {
+				return ErrTimeoutDueToConnectionLost
+			}
+		default:
+			if !isConnectedSince(s.r.transport, start, lead) {
+				return ErrTimeoutDueToConnectionLost
+			}
+		}
+		return ErrTimeout
+
+	default:
+		return err
+	}
+}
+
+func (s *EtcdServer) KV() mvcc.ConsistentWatchableKV { return s.kv }
+func (s *EtcdServer) Backend() backend.Backend {
+	s.bemu.Lock()
+	defer s.bemu.Unlock()
+	return s.be
+}
+
+func (s *EtcdServer) AuthStore() auth.AuthStore { return s.authStore }
+
+func (s *EtcdServer) restoreAlarms() error {
+	s.applyV3 = s.newApplierV3()
+	as, err := v3alarm.NewAlarmStore(s)
+	if err != nil {
+		return err
+	}
+	s.alarmStore = as
+	if len(as.Get(pb.AlarmType_NOSPACE)) > 0 {
+		s.applyV3 = newApplierV3Capped(s.applyV3)
+	}
+	if len(as.Get(pb.AlarmType_CORRUPT)) > 0 {
+		s.applyV3 = newApplierV3Corrupt(s.applyV3)
+	}
+	return nil
+}
+
+// goAttach creates a goroutine on a given function and tracks it using
+// the etcdserver waitgroup.
+func (s *EtcdServer) goAttach(f func()) {
+	s.wgMu.RLock() // this blocks with ongoing close(s.stopping)
+	defer s.wgMu.RUnlock()
+	select {
+	case <-s.stopping:
+		if lg := s.getLogger(); lg != nil {
+			lg.Warn("server has stopped; skipping goAttach")
+		} else {
+			plog.Warning("server has stopped (skipping goAttach)")
+		}
+		return
+	default:
+	}
+
+	// now safe to add since waitgroup wait has not started yet
+	s.wg.Add(1)
+	go func() {
+		defer s.wg.Done()
+		f()
+	}()
+}
+
+func (s *EtcdServer) Alarms() []*pb.AlarmMember {
+	return s.alarmStore.Get(pb.AlarmType_NONE)
+}
+
+func (s *EtcdServer) Logger() *zap.Logger {
+	return s.lg
+}
+
+// IsLearner returns if the local member is raft learner
+func (s *EtcdServer) IsLearner() bool {
+	return s.cluster.IsLocalMemberLearner()
+}
+
+// IsMemberExist returns if the member with the given id exists in cluster.
+func (s *EtcdServer) IsMemberExist(id types.ID) bool {
+	return s.cluster.IsMemberExist(id)
+}
+
+// raftStatus returns the raft status of this etcd node.
+func (s *EtcdServer) raftStatus() raft.Status {
+	return s.r.Node.Status()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go b/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go
new file mode 100644
index 0000000..09e2255
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/server_access_control.go
@@ -0,0 +1,65 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import "sync"
+
+// AccessController controls etcd server HTTP request access.
+type AccessController struct {
+	corsMu          sync.RWMutex
+	CORS            map[string]struct{}
+	hostWhitelistMu sync.RWMutex
+	HostWhitelist   map[string]struct{}
+}
+
+// NewAccessController returns a new "AccessController" with default "*" values.
+func NewAccessController() *AccessController {
+	return &AccessController{
+		CORS:          map[string]struct{}{"*": {}},
+		HostWhitelist: map[string]struct{}{"*": {}},
+	}
+}
+
+// OriginAllowed determines whether the server will allow a given CORS origin.
+// If CORS is empty, allow all.
+func (ac *AccessController) OriginAllowed(origin string) bool {
+	ac.corsMu.RLock()
+	defer ac.corsMu.RUnlock()
+	if len(ac.CORS) == 0 { // allow all
+		return true
+	}
+	_, ok := ac.CORS["*"]
+	if ok {
+		return true
+	}
+	_, ok = ac.CORS[origin]
+	return ok
+}
+
+// IsHostWhitelisted returns true if the host is whitelisted.
+// If whitelist is empty, allow all.
+func (ac *AccessController) IsHostWhitelisted(host string) bool {
+	ac.hostWhitelistMu.RLock()
+	defer ac.hostWhitelistMu.RUnlock()
+	if len(ac.HostWhitelist) == 0 { // allow all
+		return true
+	}
+	_, ok := ac.HostWhitelist["*"]
+	if ok {
+		return true
+	}
+	_, ok = ac.HostWhitelist[host]
+	return ok
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/snapshot_merge.go b/vendor/go.etcd.io/etcd/etcdserver/snapshot_merge.go
new file mode 100644
index 0000000..4177768
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/snapshot_merge.go
@@ -0,0 +1,100 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"io"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/raft/raftpb"
+
+	humanize "github.com/dustin/go-humanize"
+	"go.uber.org/zap"
+)
+
+// createMergedSnapshotMessage creates a snapshot message that contains: raft status (term, conf),
+// a snapshot of v2 store inside raft.Snapshot as []byte, a snapshot of v3 KV in the top level message
+// as ReadCloser.
+func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapt, snapi uint64, confState raftpb.ConfState) snap.Message {
+	// get a snapshot of v2 store as []byte
+	clone := s.v2store.Clone()
+	d, err := clone.SaveNoCopy()
+	if err != nil {
+		if lg := s.getLogger(); lg != nil {
+			lg.Panic("failed to save v2 store data", zap.Error(err))
+		} else {
+			plog.Panicf("store save should never fail: %v", err)
+		}
+	}
+
+	// commit kv to write metadata(for example: consistent index).
+	s.KV().Commit()
+	dbsnap := s.be.Snapshot()
+	// get a snapshot of v3 KV as readCloser
+	rc := newSnapshotReaderCloser(s.getLogger(), dbsnap)
+
+	// put the []byte snapshot of store into raft snapshot and return the merged snapshot with
+	// KV readCloser snapshot.
+	snapshot := raftpb.Snapshot{
+		Metadata: raftpb.SnapshotMetadata{
+			Index:     snapi,
+			Term:      snapt,
+			ConfState: confState,
+		},
+		Data: d,
+	}
+	m.Snapshot = snapshot
+
+	return *snap.NewMessage(m, rc, dbsnap.Size())
+}
+
+func newSnapshotReaderCloser(lg *zap.Logger, snapshot backend.Snapshot) io.ReadCloser {
+	pr, pw := io.Pipe()
+	go func() {
+		n, err := snapshot.WriteTo(pw)
+		if err == nil {
+			if lg != nil {
+				lg.Info(
+					"sent database snapshot to writer",
+					zap.Int64("bytes", n),
+					zap.String("size", humanize.Bytes(uint64(n))),
+				)
+			} else {
+				plog.Infof("wrote database snapshot out [total bytes: %d]", n)
+			}
+		} else {
+			if lg != nil {
+				lg.Warn(
+					"failed to send database snapshot to writer",
+					zap.String("size", humanize.Bytes(uint64(n))),
+					zap.Error(err),
+				)
+			} else {
+				plog.Warningf("failed to write database snapshot out [written bytes: %d]: %v", n, err)
+			}
+		}
+		pw.CloseWithError(err)
+		err = snapshot.Close()
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to close database snapshot", zap.Error(err))
+			} else {
+				plog.Panicf("failed to close database snapshot: %v", err)
+			}
+		}
+	}()
+	return pr
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/storage.go b/vendor/go.etcd.io/etcd/etcdserver/storage.go
new file mode 100644
index 0000000..d57b6f9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/storage.go
@@ -0,0 +1,116 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"io"
+
+	"go.etcd.io/etcd/etcdserver/api/snap"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/pkg/types"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/wal"
+	"go.etcd.io/etcd/wal/walpb"
+
+	"go.uber.org/zap"
+)
+
+type Storage interface {
+	// Save function saves ents and state to the underlying stable storage.
+	// Save MUST block until st and ents are on stable storage.
+	Save(st raftpb.HardState, ents []raftpb.Entry) error
+	// SaveSnap function saves snapshot to the underlying stable storage.
+	SaveSnap(snap raftpb.Snapshot) error
+	// Close closes the Storage and performs finalization.
+	Close() error
+}
+
+type storage struct {
+	*wal.WAL
+	*snap.Snapshotter
+}
+
+func NewStorage(w *wal.WAL, s *snap.Snapshotter) Storage {
+	return &storage{w, s}
+}
+
+// SaveSnap saves the snapshot to disk and release the locked
+// wal files since they will not be used.
+func (st *storage) SaveSnap(snap raftpb.Snapshot) error {
+	walsnap := walpb.Snapshot{
+		Index: snap.Metadata.Index,
+		Term:  snap.Metadata.Term,
+	}
+	err := st.WAL.SaveSnapshot(walsnap)
+	if err != nil {
+		return err
+	}
+	err = st.Snapshotter.SaveSnap(snap)
+	if err != nil {
+		return err
+	}
+	return st.WAL.ReleaseLockTo(snap.Metadata.Index)
+}
+
+func readWAL(lg *zap.Logger, waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID, st raftpb.HardState, ents []raftpb.Entry) {
+	var (
+		err       error
+		wmetadata []byte
+	)
+
+	repaired := false
+	for {
+		if w, err = wal.Open(lg, waldir, snap); err != nil {
+			if lg != nil {
+				lg.Fatal("failed to open WAL", zap.Error(err))
+			} else {
+				plog.Fatalf("open wal error: %v", err)
+			}
+		}
+		if wmetadata, st, ents, err = w.ReadAll(); err != nil {
+			w.Close()
+			// we can only repair ErrUnexpectedEOF and we never repair twice.
+			if repaired || err != io.ErrUnexpectedEOF {
+				if lg != nil {
+					lg.Fatal("failed to read WAL, cannot be repaired", zap.Error(err))
+				} else {
+					plog.Fatalf("read wal error (%v) and cannot be repaired", err)
+				}
+			}
+			if !wal.Repair(lg, waldir) {
+				if lg != nil {
+					lg.Fatal("failed to repair WAL", zap.Error(err))
+				} else {
+					plog.Fatalf("WAL error (%v) cannot be repaired", err)
+				}
+			} else {
+				if lg != nil {
+					lg.Info("repaired WAL", zap.Error(err))
+				} else {
+					plog.Infof("repaired WAL error (%v)", err)
+				}
+				repaired = true
+			}
+			continue
+		}
+		break
+	}
+	var metadata pb.Metadata
+	pbutil.MustUnmarshal(&metadata, wmetadata)
+	id = types.ID(metadata.NodeID)
+	cid = types.ID(metadata.ClusterID)
+	return w, id, cid, st, ents
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/util.go b/vendor/go.etcd.io/etcd/etcdserver/util.go
new file mode 100644
index 0000000..fe5024e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/util.go
@@ -0,0 +1,168 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	"go.etcd.io/etcd/etcdserver/api/rafthttp"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"go.uber.org/zap"
+)
+
+// isConnectedToQuorumSince checks whether the local member is connected to the
+// quorum of the cluster since the given time.
+func isConnectedToQuorumSince(transport rafthttp.Transporter, since time.Time, self types.ID, members []*membership.Member) bool {
+	return numConnectedSince(transport, since, self, members) >= (len(members)/2)+1
+}
+
+// isConnectedSince checks whether the local member is connected to the
+// remote member since the given time.
+func isConnectedSince(transport rafthttp.Transporter, since time.Time, remote types.ID) bool {
+	t := transport.ActiveSince(remote)
+	return !t.IsZero() && t.Before(since)
+}
+
+// isConnectedFullySince checks whether the local member is connected to all
+// members in the cluster since the given time.
+func isConnectedFullySince(transport rafthttp.Transporter, since time.Time, self types.ID, members []*membership.Member) bool {
+	return numConnectedSince(transport, since, self, members) == len(members)
+}
+
+// numConnectedSince counts how many members are connected to the local member
+// since the given time.
+func numConnectedSince(transport rafthttp.Transporter, since time.Time, self types.ID, members []*membership.Member) int {
+	connectedNum := 0
+	for _, m := range members {
+		if m.ID == self || isConnectedSince(transport, since, m.ID) {
+			connectedNum++
+		}
+	}
+	return connectedNum
+}
+
+// longestConnected chooses the member with longest active-since-time.
+// It returns false, if nothing is active.
+func longestConnected(tp rafthttp.Transporter, membs []types.ID) (types.ID, bool) {
+	var longest types.ID
+	var oldest time.Time
+	for _, id := range membs {
+		tm := tp.ActiveSince(id)
+		if tm.IsZero() { // inactive
+			continue
+		}
+
+		if oldest.IsZero() { // first longest candidate
+			oldest = tm
+			longest = id
+		}
+
+		if tm.Before(oldest) {
+			oldest = tm
+			longest = id
+		}
+	}
+	if uint64(longest) == 0 {
+		return longest, false
+	}
+	return longest, true
+}
+
+type notifier struct {
+	c   chan struct{}
+	err error
+}
+
+func newNotifier() *notifier {
+	return &notifier{
+		c: make(chan struct{}),
+	}
+}
+
+func (nc *notifier) notify(err error) {
+	nc.err = err
+	close(nc.c)
+}
+
+func warnOfExpensiveRequest(lg *zap.Logger, now time.Time, reqStringer fmt.Stringer, respMsg proto.Message, err error) {
+	var resp string
+	if !isNil(respMsg) {
+		resp = fmt.Sprintf("size:%d", proto.Size(respMsg))
+	}
+	warnOfExpensiveGenericRequest(lg, now, reqStringer, "", resp, err)
+}
+
+func warnOfExpensiveReadOnlyTxnRequest(lg *zap.Logger, now time.Time, r *pb.TxnRequest, txnResponse *pb.TxnResponse, err error) {
+	reqStringer := pb.NewLoggableTxnRequest(r)
+	var resp string
+	if !isNil(txnResponse) {
+		var resps []string
+		for _, r := range txnResponse.Responses {
+			switch op := r.Response.(type) {
+			case *pb.ResponseOp_ResponseRange:
+				resps = append(resps, fmt.Sprintf("range_response_count:%d", len(op.ResponseRange.Kvs)))
+			default:
+				// only range responses should be in a read only txn request
+			}
+		}
+		resp = fmt.Sprintf("responses:<%s> size:%d", strings.Join(resps, " "), proto.Size(txnResponse))
+	}
+	warnOfExpensiveGenericRequest(lg, now, reqStringer, "read-only range ", resp, err)
+}
+
+func warnOfExpensiveReadOnlyRangeRequest(lg *zap.Logger, now time.Time, reqStringer fmt.Stringer, rangeResponse *pb.RangeResponse, err error) {
+	var resp string
+	if !isNil(rangeResponse) {
+		resp = fmt.Sprintf("range_response_count:%d size:%d", len(rangeResponse.Kvs), proto.Size(rangeResponse))
+	}
+	warnOfExpensiveGenericRequest(lg, now, reqStringer, "read-only range ", resp, err)
+}
+
+func warnOfExpensiveGenericRequest(lg *zap.Logger, now time.Time, reqStringer fmt.Stringer, prefix string, resp string, err error) {
+	d := time.Since(now)
+	if d > warnApplyDuration {
+		if lg != nil {
+			lg.Warn(
+				"apply request took too long",
+				zap.Duration("took", d),
+				zap.Duration("expected-duration", warnApplyDuration),
+				zap.String("prefix", prefix),
+				zap.String("request", reqStringer.String()),
+				zap.String("response", resp),
+				zap.Error(err),
+			)
+		} else {
+			var result string
+			if err != nil {
+				result = fmt.Sprintf("error:%v", err)
+			} else {
+				result = resp
+			}
+			plog.Warningf("%srequest %q with result %q took too long (%v) to execute", prefix, reqStringer.String(), result, d)
+		}
+		slowApplies.Inc()
+	}
+}
+
+func isNil(msg proto.Message) bool {
+	return msg == nil || reflect.ValueOf(msg).IsNil()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/v2_server.go b/vendor/go.etcd.io/etcd/etcdserver/v2_server.go
new file mode 100644
index 0000000..9238b2d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/v2_server.go
@@ -0,0 +1,165 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"context"
+	"time"
+
+	"go.etcd.io/etcd/etcdserver/api/v2store"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+)
+
+type RequestV2 pb.Request
+
+type RequestV2Handler interface {
+	Post(ctx context.Context, r *RequestV2) (Response, error)
+	Put(ctx context.Context, r *RequestV2) (Response, error)
+	Delete(ctx context.Context, r *RequestV2) (Response, error)
+	QGet(ctx context.Context, r *RequestV2) (Response, error)
+	Get(ctx context.Context, r *RequestV2) (Response, error)
+	Head(ctx context.Context, r *RequestV2) (Response, error)
+}
+
+type reqV2HandlerEtcdServer struct {
+	reqV2HandlerStore
+	s *EtcdServer
+}
+
+type reqV2HandlerStore struct {
+	store   v2store.Store
+	applier ApplierV2
+}
+
+func NewStoreRequestV2Handler(s v2store.Store, applier ApplierV2) RequestV2Handler {
+	return &reqV2HandlerStore{s, applier}
+}
+
+func (a *reqV2HandlerStore) Post(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.applier.Post(r), nil
+}
+
+func (a *reqV2HandlerStore) Put(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.applier.Put(r), nil
+}
+
+func (a *reqV2HandlerStore) Delete(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.applier.Delete(r), nil
+}
+
+func (a *reqV2HandlerStore) QGet(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.applier.QGet(r), nil
+}
+
+func (a *reqV2HandlerStore) Get(ctx context.Context, r *RequestV2) (Response, error) {
+	if r.Wait {
+		wc, err := a.store.Watch(r.Path, r.Recursive, r.Stream, r.Since)
+		return Response{Watcher: wc}, err
+	}
+	ev, err := a.store.Get(r.Path, r.Recursive, r.Sorted)
+	return Response{Event: ev}, err
+}
+
+func (a *reqV2HandlerStore) Head(ctx context.Context, r *RequestV2) (Response, error) {
+	ev, err := a.store.Get(r.Path, r.Recursive, r.Sorted)
+	return Response{Event: ev}, err
+}
+
+func (a *reqV2HandlerEtcdServer) Post(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.processRaftRequest(ctx, r)
+}
+
+func (a *reqV2HandlerEtcdServer) Put(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.processRaftRequest(ctx, r)
+}
+
+func (a *reqV2HandlerEtcdServer) Delete(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.processRaftRequest(ctx, r)
+}
+
+func (a *reqV2HandlerEtcdServer) QGet(ctx context.Context, r *RequestV2) (Response, error) {
+	return a.processRaftRequest(ctx, r)
+}
+
+func (a *reqV2HandlerEtcdServer) processRaftRequest(ctx context.Context, r *RequestV2) (Response, error) {
+	data, err := ((*pb.Request)(r)).Marshal()
+	if err != nil {
+		return Response{}, err
+	}
+	ch := a.s.w.Register(r.ID)
+
+	start := time.Now()
+	a.s.r.Propose(ctx, data)
+	proposalsPending.Inc()
+	defer proposalsPending.Dec()
+
+	select {
+	case x := <-ch:
+		resp := x.(Response)
+		return resp, resp.Err
+	case <-ctx.Done():
+		proposalsFailed.Inc()
+		a.s.w.Trigger(r.ID, nil) // GC wait
+		return Response{}, a.s.parseProposeCtxErr(ctx.Err(), start)
+	case <-a.s.stopping:
+	}
+	return Response{}, ErrStopped
+}
+
+func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
+	r.ID = s.reqIDGen.Next()
+	h := &reqV2HandlerEtcdServer{
+		reqV2HandlerStore: reqV2HandlerStore{
+			store:   s.v2store,
+			applier: s.applyV2,
+		},
+		s: s,
+	}
+	rp := &r
+	resp, err := ((*RequestV2)(rp)).Handle(ctx, h)
+	resp.Term, resp.Index = s.Term(), s.CommittedIndex()
+	return resp, err
+}
+
+// Handle interprets r and performs an operation on s.store according to r.Method
+// and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET" with
+// Quorum == true, r will be sent through consensus before performing its
+// respective operation. Do will block until an action is performed or there is
+// an error.
+func (r *RequestV2) Handle(ctx context.Context, v2api RequestV2Handler) (Response, error) {
+	if r.Method == "GET" && r.Quorum {
+		r.Method = "QGET"
+	}
+	switch r.Method {
+	case "POST":
+		return v2api.Post(ctx, r)
+	case "PUT":
+		return v2api.Put(ctx, r)
+	case "DELETE":
+		return v2api.Delete(ctx, r)
+	case "QGET":
+		return v2api.QGet(ctx, r)
+	case "GET":
+		return v2api.Get(ctx, r)
+	case "HEAD":
+		return v2api.Head(ctx, r)
+	}
+	return Response{}, ErrUnknownMethod
+}
+
+func (r *RequestV2) String() string {
+	rpb := pb.Request(*r)
+	return rpb.String()
+}
diff --git a/vendor/go.etcd.io/etcd/etcdserver/v3_server.go b/vendor/go.etcd.io/etcd/etcdserver/v3_server.go
new file mode 100644
index 0000000..b208461
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/v3_server.go
@@ -0,0 +1,768 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"time"
+
+	"go.etcd.io/etcd/auth"
+	"go.etcd.io/etcd/etcdserver/api/membership"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/lease/leasehttp"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/raft"
+
+	"github.com/gogo/protobuf/proto"
+	"go.uber.org/zap"
+)
+
+const (
+	// In the health case, there might be a small gap (10s of entries) between
+	// the applied index and committed index.
+	// However, if the committed entries are very heavy to apply, the gap might grow.
+	// We should stop accepting new proposals if the gap growing to a certain point.
+	maxGapBetweenApplyAndCommitIndex = 5000
+)
+
+type RaftKV interface {
+	Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeResponse, error)
+	Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error)
+	DeleteRange(ctx context.Context, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error)
+	Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error)
+	Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error)
+}
+
+type Lessor interface {
+	// LeaseGrant sends LeaseGrant request to raft and apply it after committed.
+	LeaseGrant(ctx context.Context, r *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error)
+	// LeaseRevoke sends LeaseRevoke request to raft and apply it after committed.
+	LeaseRevoke(ctx context.Context, r *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error)
+
+	// LeaseRenew renews the lease with given ID. The renewed TTL is returned. Or an error
+	// is returned.
+	LeaseRenew(ctx context.Context, id lease.LeaseID) (int64, error)
+
+	// LeaseTimeToLive retrieves lease information.
+	LeaseTimeToLive(ctx context.Context, r *pb.LeaseTimeToLiveRequest) (*pb.LeaseTimeToLiveResponse, error)
+
+	// LeaseLeases lists all leases.
+	LeaseLeases(ctx context.Context, r *pb.LeaseLeasesRequest) (*pb.LeaseLeasesResponse, error)
+}
+
+type Authenticator interface {
+	AuthEnable(ctx context.Context, r *pb.AuthEnableRequest) (*pb.AuthEnableResponse, error)
+	AuthDisable(ctx context.Context, r *pb.AuthDisableRequest) (*pb.AuthDisableResponse, error)
+	Authenticate(ctx context.Context, r *pb.AuthenticateRequest) (*pb.AuthenticateResponse, error)
+	UserAdd(ctx context.Context, r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
+	UserDelete(ctx context.Context, r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
+	UserChangePassword(ctx context.Context, r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error)
+	UserGrantRole(ctx context.Context, r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error)
+	UserGet(ctx context.Context, r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error)
+	UserRevokeRole(ctx context.Context, r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error)
+	RoleAdd(ctx context.Context, r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error)
+	RoleGrantPermission(ctx context.Context, r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error)
+	RoleGet(ctx context.Context, r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error)
+	RoleRevokePermission(ctx context.Context, r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error)
+	RoleDelete(ctx context.Context, r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
+	UserList(ctx context.Context, r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
+	RoleList(ctx context.Context, r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
+}
+
+func (s *EtcdServer) Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	var resp *pb.RangeResponse
+	var err error
+	defer func(start time.Time) {
+		warnOfExpensiveReadOnlyRangeRequest(s.getLogger(), start, r, resp, err)
+	}(time.Now())
+
+	if !r.Serializable {
+		err = s.linearizableReadNotify(ctx)
+		if err != nil {
+			return nil, err
+		}
+	}
+	chk := func(ai *auth.AuthInfo) error {
+		return s.authStore.IsRangePermitted(ai, r.Key, r.RangeEnd)
+	}
+
+	get := func() { resp, err = s.applyV3Base.Range(nil, r) }
+	if serr := s.doSerialize(ctx, chk, get); serr != nil {
+		err = serr
+		return nil, err
+	}
+	return resp, err
+}
+
+func (s *EtcdServer) Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{Put: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.PutResponse), nil
+}
+
+func (s *EtcdServer) DeleteRange(ctx context.Context, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{DeleteRange: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.DeleteRangeResponse), nil
+}
+
+func (s *EtcdServer) Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if isTxnReadonly(r) {
+		if !isTxnSerializable(r) {
+			err := s.linearizableReadNotify(ctx)
+			if err != nil {
+				return nil, err
+			}
+		}
+		var resp *pb.TxnResponse
+		var err error
+		chk := func(ai *auth.AuthInfo) error {
+			return checkTxnAuth(s.authStore, ai, r)
+		}
+
+		defer func(start time.Time) {
+			warnOfExpensiveReadOnlyTxnRequest(s.getLogger(), start, r, resp, err)
+		}(time.Now())
+
+		get := func() { resp, err = s.applyV3Base.Txn(r) }
+		if serr := s.doSerialize(ctx, chk, get); serr != nil {
+			return nil, serr
+		}
+		return resp, err
+	}
+
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{Txn: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.TxnResponse), nil
+}
+
+func isTxnSerializable(r *pb.TxnRequest) bool {
+	for _, u := range r.Success {
+		if r := u.GetRequestRange(); r == nil || !r.Serializable {
+			return false
+		}
+	}
+	for _, u := range r.Failure {
+		if r := u.GetRequestRange(); r == nil || !r.Serializable {
+			return false
+		}
+	}
+	return true
+}
+
+func isTxnReadonly(r *pb.TxnRequest) bool {
+	for _, u := range r.Success {
+		if r := u.GetRequestRange(); r == nil {
+			return false
+		}
+	}
+	for _, u := range r.Failure {
+		if r := u.GetRequestRange(); r == nil {
+			return false
+		}
+	}
+	return true
+}
+
+func (s *EtcdServer) Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error) {
+	result, err := s.processInternalRaftRequestOnce(ctx, pb.InternalRaftRequest{Compaction: r})
+	if r.Physical && result != nil && result.physc != nil {
+		<-result.physc
+		// The compaction is done deleting keys; the hash is now settled
+		// but the data is not necessarily committed. If there's a crash,
+		// the hash may revert to a hash prior to compaction completing
+		// if the compaction resumes. Force the finished compaction to
+		// commit so it won't resume following a crash.
+		s.be.ForceCommit()
+	}
+	if err != nil {
+		return nil, err
+	}
+	if result.err != nil {
+		return nil, result.err
+	}
+	resp := result.resp.(*pb.CompactionResponse)
+	if resp == nil {
+		resp = &pb.CompactionResponse{}
+	}
+	if resp.Header == nil {
+		resp.Header = &pb.ResponseHeader{}
+	}
+	resp.Header.Revision = s.kv.Rev()
+	return resp, nil
+}
+
+func (s *EtcdServer) LeaseGrant(ctx context.Context, r *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	// no id given? choose one
+	for r.ID == int64(lease.NoLease) {
+		// only use positive int64 id's
+		r.ID = int64(s.reqIDGen.Next() & ((1 << 63) - 1))
+	}
+	resp, err := s.raftRequestOnce(ctx, pb.InternalRaftRequest{LeaseGrant: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.LeaseGrantResponse), nil
+}
+
+func (s *EtcdServer) LeaseRevoke(ctx context.Context, r *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	resp, err := s.raftRequestOnce(ctx, pb.InternalRaftRequest{LeaseRevoke: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.LeaseRevokeResponse), nil
+}
+
+func (s *EtcdServer) LeaseRenew(ctx context.Context, id lease.LeaseID) (int64, error) {
+	ttl, err := s.lessor.Renew(id)
+	if err == nil { // already requested to primary lessor(leader)
+		return ttl, nil
+	}
+	if err != lease.ErrNotPrimary {
+		return -1, err
+	}
+
+	cctx, cancel := context.WithTimeout(ctx, s.Cfg.ReqTimeout())
+	defer cancel()
+
+	// renewals don't go through raft; forward to leader manually
+	for cctx.Err() == nil && err != nil {
+		leader, lerr := s.waitLeader(cctx)
+		if lerr != nil {
+			return -1, lerr
+		}
+		for _, url := range leader.PeerURLs {
+			lurl := url + leasehttp.LeasePrefix
+			ttl, err = leasehttp.RenewHTTP(cctx, id, lurl, s.peerRt)
+			if err == nil || err == lease.ErrLeaseNotFound {
+				return ttl, err
+			}
+		}
+	}
+
+	if cctx.Err() == context.DeadlineExceeded {
+		return -1, ErrTimeout
+	}
+	return -1, ErrCanceled
+}
+
+func (s *EtcdServer) LeaseTimeToLive(ctx context.Context, r *pb.LeaseTimeToLiveRequest) (*pb.LeaseTimeToLiveResponse, error) {
+	if s.Leader() == s.ID() {
+		// primary; timetolive directly from leader
+		le := s.lessor.Lookup(lease.LeaseID(r.ID))
+		if le == nil {
+			return nil, lease.ErrLeaseNotFound
+		}
+		// TODO: fill out ResponseHeader
+		resp := &pb.LeaseTimeToLiveResponse{Header: &pb.ResponseHeader{}, ID: r.ID, TTL: int64(le.Remaining().Seconds()), GrantedTTL: le.TTL()}
+		if r.Keys {
+			ks := le.Keys()
+			kbs := make([][]byte, len(ks))
+			for i := range ks {
+				kbs[i] = []byte(ks[i])
+			}
+			resp.Keys = kbs
+		}
+		return resp, nil
+	}
+
+	cctx, cancel := context.WithTimeout(ctx, s.Cfg.ReqTimeout())
+	defer cancel()
+
+	// forward to leader
+	for cctx.Err() == nil {
+		leader, err := s.waitLeader(cctx)
+		if err != nil {
+			return nil, err
+		}
+		for _, url := range leader.PeerURLs {
+			lurl := url + leasehttp.LeaseInternalPrefix
+			resp, err := leasehttp.TimeToLiveHTTP(cctx, lease.LeaseID(r.ID), r.Keys, lurl, s.peerRt)
+			if err == nil {
+				return resp.LeaseTimeToLiveResponse, nil
+			}
+			if err == lease.ErrLeaseNotFound {
+				return nil, err
+			}
+		}
+	}
+
+	if cctx.Err() == context.DeadlineExceeded {
+		return nil, ErrTimeout
+	}
+	return nil, ErrCanceled
+}
+
+func (s *EtcdServer) LeaseLeases(ctx context.Context, r *pb.LeaseLeasesRequest) (*pb.LeaseLeasesResponse, error) {
+	ls := s.lessor.Leases()
+	lss := make([]*pb.LeaseStatus, len(ls))
+	for i := range ls {
+		lss[i] = &pb.LeaseStatus{ID: int64(ls[i].ID)}
+	}
+	return &pb.LeaseLeasesResponse{Header: newHeader(s), Leases: lss}, nil
+}
+
+func (s *EtcdServer) waitLeader(ctx context.Context) (*membership.Member, error) {
+	leader := s.cluster.Member(s.Leader())
+	for leader == nil {
+		// wait an election
+		dur := time.Duration(s.Cfg.ElectionTicks) * time.Duration(s.Cfg.TickMs) * time.Millisecond
+		select {
+		case <-time.After(dur):
+			leader = s.cluster.Member(s.Leader())
+		case <-s.stopping:
+			return nil, ErrStopped
+		case <-ctx.Done():
+			return nil, ErrNoLeader
+		}
+	}
+	if leader == nil || len(leader.PeerURLs) == 0 {
+		return nil, ErrNoLeader
+	}
+	return leader, nil
+}
+
+func (s *EtcdServer) Alarm(ctx context.Context, r *pb.AlarmRequest) (*pb.AlarmResponse, error) {
+	resp, err := s.raftRequestOnce(ctx, pb.InternalRaftRequest{Alarm: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AlarmResponse), nil
+}
+
+func (s *EtcdServer) AuthEnable(ctx context.Context, r *pb.AuthEnableRequest) (*pb.AuthEnableResponse, error) {
+	resp, err := s.raftRequestOnce(ctx, pb.InternalRaftRequest{AuthEnable: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthEnableResponse), nil
+}
+
+func (s *EtcdServer) AuthDisable(ctx context.Context, r *pb.AuthDisableRequest) (*pb.AuthDisableResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthDisable: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthDisableResponse), nil
+}
+
+func (s *EtcdServer) Authenticate(ctx context.Context, r *pb.AuthenticateRequest) (*pb.AuthenticateResponse, error) {
+	if err := s.linearizableReadNotify(ctx); err != nil {
+		return nil, err
+	}
+
+	lg := s.getLogger()
+
+	var resp proto.Message
+	for {
+		checkedRevision, err := s.AuthStore().CheckPassword(r.Name, r.Password)
+		if err != nil {
+			if err != auth.ErrAuthNotEnabled {
+				if lg != nil {
+					lg.Warn(
+						"invalid authentication was requested",
+						zap.String("user", r.Name),
+						zap.Error(err),
+					)
+				} else {
+					plog.Errorf("invalid authentication request to user %s was issued", r.Name)
+				}
+			}
+			return nil, err
+		}
+
+		st, err := s.AuthStore().GenTokenPrefix()
+		if err != nil {
+			return nil, err
+		}
+
+		internalReq := &pb.InternalAuthenticateRequest{
+			Name:        r.Name,
+			Password:    r.Password,
+			SimpleToken: st,
+		}
+
+		resp, err = s.raftRequestOnce(ctx, pb.InternalRaftRequest{Authenticate: internalReq})
+		if err != nil {
+			return nil, err
+		}
+		if checkedRevision == s.AuthStore().Revision() {
+			break
+		}
+
+		if lg != nil {
+			lg.Info("revision when password checked became stale; retrying")
+		} else {
+			plog.Infof("revision when password checked is obsolete, retrying")
+		}
+	}
+
+	return resp.(*pb.AuthenticateResponse), nil
+}
+
+func (s *EtcdServer) UserAdd(ctx context.Context, r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserAdd: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserAddResponse), nil
+}
+
+func (s *EtcdServer) UserDelete(ctx context.Context, r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserDelete: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserDeleteResponse), nil
+}
+
+func (s *EtcdServer) UserChangePassword(ctx context.Context, r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserChangePassword: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserChangePasswordResponse), nil
+}
+
+func (s *EtcdServer) UserGrantRole(ctx context.Context, r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserGrantRole: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserGrantRoleResponse), nil
+}
+
+func (s *EtcdServer) UserGet(ctx context.Context, r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserGet: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserGetResponse), nil
+}
+
+func (s *EtcdServer) UserList(ctx context.Context, r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserList: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserListResponse), nil
+}
+
+func (s *EtcdServer) UserRevokeRole(ctx context.Context, r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthUserRevokeRole: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthUserRevokeRoleResponse), nil
+}
+
+func (s *EtcdServer) RoleAdd(ctx context.Context, r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleAdd: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleAddResponse), nil
+}
+
+func (s *EtcdServer) RoleGrantPermission(ctx context.Context, r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleGrantPermission: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleGrantPermissionResponse), nil
+}
+
+func (s *EtcdServer) RoleGet(ctx context.Context, r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleGet: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleGetResponse), nil
+}
+
+func (s *EtcdServer) RoleList(ctx context.Context, r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleList: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleListResponse), nil
+}
+
+func (s *EtcdServer) RoleRevokePermission(ctx context.Context, r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleRevokePermission: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleRevokePermissionResponse), nil
+}
+
+func (s *EtcdServer) RoleDelete(ctx context.Context, r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	resp, err := s.raftRequest(ctx, pb.InternalRaftRequest{AuthRoleDelete: r})
+	if err != nil {
+		return nil, err
+	}
+	return resp.(*pb.AuthRoleDeleteResponse), nil
+}
+
+func (s *EtcdServer) raftRequestOnce(ctx context.Context, r pb.InternalRaftRequest) (proto.Message, error) {
+	result, err := s.processInternalRaftRequestOnce(ctx, r)
+	if err != nil {
+		return nil, err
+	}
+	if result.err != nil {
+		return nil, result.err
+	}
+	return result.resp, nil
+}
+
+func (s *EtcdServer) raftRequest(ctx context.Context, r pb.InternalRaftRequest) (proto.Message, error) {
+	for {
+		resp, err := s.raftRequestOnce(ctx, r)
+		if err != auth.ErrAuthOldRevision {
+			return resp, err
+		}
+	}
+}
+
+// doSerialize handles the auth logic, with permissions checked by "chk", for a serialized request "get". Returns a non-nil error on authentication failure.
+func (s *EtcdServer) doSerialize(ctx context.Context, chk func(*auth.AuthInfo) error, get func()) error {
+	ai, err := s.AuthInfoFromCtx(ctx)
+	if err != nil {
+		return err
+	}
+	if ai == nil {
+		// chk expects non-nil AuthInfo; use empty credentials
+		ai = &auth.AuthInfo{}
+	}
+	if err = chk(ai); err != nil {
+		return err
+	}
+	// fetch response for serialized request
+	get()
+	// check for stale token revision in case the auth store was updated while
+	// the request has been handled.
+	if ai.Revision != 0 && ai.Revision != s.authStore.Revision() {
+		return auth.ErrAuthOldRevision
+	}
+	return nil
+}
+
+func (s *EtcdServer) processInternalRaftRequestOnce(ctx context.Context, r pb.InternalRaftRequest) (*applyResult, error) {
+	ai := s.getAppliedIndex()
+	ci := s.getCommittedIndex()
+	if ci > ai+maxGapBetweenApplyAndCommitIndex {
+		return nil, ErrTooManyRequests
+	}
+
+	r.Header = &pb.RequestHeader{
+		ID: s.reqIDGen.Next(),
+	}
+
+	authInfo, err := s.AuthInfoFromCtx(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if authInfo != nil {
+		r.Header.Username = authInfo.Username
+		r.Header.AuthRevision = authInfo.Revision
+	}
+
+	data, err := r.Marshal()
+	if err != nil {
+		return nil, err
+	}
+
+	if len(data) > int(s.Cfg.MaxRequestBytes) {
+		return nil, ErrRequestTooLarge
+	}
+
+	id := r.ID
+	if id == 0 {
+		id = r.Header.ID
+	}
+	ch := s.w.Register(id)
+
+	cctx, cancel := context.WithTimeout(ctx, s.Cfg.ReqTimeout())
+	defer cancel()
+
+	start := time.Now()
+	err = s.r.Propose(cctx, data)
+	if err != nil {
+		proposalsFailed.Inc()
+		s.w.Trigger(id, nil) // GC wait
+		return nil, err
+	}
+	proposalsPending.Inc()
+	defer proposalsPending.Dec()
+
+	select {
+	case x := <-ch:
+		return x.(*applyResult), nil
+	case <-cctx.Done():
+		proposalsFailed.Inc()
+		s.w.Trigger(id, nil) // GC wait
+		return nil, s.parseProposeCtxErr(cctx.Err(), start)
+	case <-s.done:
+		return nil, ErrStopped
+	}
+}
+
+// Watchable returns a watchable interface attached to the etcdserver.
+func (s *EtcdServer) Watchable() mvcc.WatchableKV { return s.KV() }
+
+func (s *EtcdServer) linearizableReadLoop() {
+	var rs raft.ReadState
+
+	for {
+		ctxToSend := make([]byte, 8)
+		id1 := s.reqIDGen.Next()
+		binary.BigEndian.PutUint64(ctxToSend, id1)
+		leaderChangedNotifier := s.leaderChangedNotify()
+		select {
+		case <-leaderChangedNotifier:
+			continue
+		case <-s.readwaitc:
+		case <-s.stopping:
+			return
+		}
+
+		nextnr := newNotifier()
+
+		s.readMu.Lock()
+		nr := s.readNotifier
+		s.readNotifier = nextnr
+		s.readMu.Unlock()
+
+		lg := s.getLogger()
+		cctx, cancel := context.WithTimeout(context.Background(), s.Cfg.ReqTimeout())
+		if err := s.r.ReadIndex(cctx, ctxToSend); err != nil {
+			cancel()
+			if err == raft.ErrStopped {
+				return
+			}
+			if lg != nil {
+				lg.Warn("failed to get read index from Raft", zap.Error(err))
+			} else {
+				plog.Errorf("failed to get read index from raft: %v", err)
+			}
+			readIndexFailed.Inc()
+			nr.notify(err)
+			continue
+		}
+		cancel()
+
+		var (
+			timeout bool
+			done    bool
+		)
+		for !timeout && !done {
+			select {
+			case rs = <-s.r.readStateC:
+				done = bytes.Equal(rs.RequestCtx, ctxToSend)
+				if !done {
+					// a previous request might time out. now we should ignore the response of it and
+					// continue waiting for the response of the current requests.
+					id2 := uint64(0)
+					if len(rs.RequestCtx) == 8 {
+						id2 = binary.BigEndian.Uint64(rs.RequestCtx)
+					}
+					if lg != nil {
+						lg.Warn(
+							"ignored out-of-date read index response; local node read indexes queueing up and waiting to be in sync with leader",
+							zap.Uint64("sent-request-id", id1),
+							zap.Uint64("received-request-id", id2),
+						)
+					} else {
+						plog.Warningf("ignored out-of-date read index response; local node read indexes queueing up and waiting to be in sync with leader (request ID want %d, got %d)", id1, id2)
+					}
+					slowReadIndex.Inc()
+				}
+			case <-leaderChangedNotifier:
+				timeout = true
+				readIndexFailed.Inc()
+				// return a retryable error.
+				nr.notify(ErrLeaderChanged)
+			case <-time.After(s.Cfg.ReqTimeout()):
+				if lg != nil {
+					lg.Warn("timed out waiting for read index response (local node might have slow network)", zap.Duration("timeout", s.Cfg.ReqTimeout()))
+				} else {
+					plog.Warningf("timed out waiting for read index response (local node might have slow network)")
+				}
+				nr.notify(ErrTimeout)
+				timeout = true
+				slowReadIndex.Inc()
+			case <-s.stopping:
+				return
+			}
+		}
+		if !done {
+			continue
+		}
+
+		if ai := s.getAppliedIndex(); ai < rs.Index {
+			select {
+			case <-s.applyWait.Wait(rs.Index):
+			case <-s.stopping:
+				return
+			}
+		}
+		// unblock all l-reads requested at indices before rs.Index
+		nr.notify(nil)
+	}
+}
+
+func (s *EtcdServer) linearizableReadNotify(ctx context.Context) error {
+	s.readMu.RLock()
+	nc := s.readNotifier
+	s.readMu.RUnlock()
+
+	// signal linearizable loop for current notify if it hasn't been already
+	select {
+	case s.readwaitc <- struct{}{}:
+	default:
+	}
+
+	// wait for read state notification
+	select {
+	case <-nc.c:
+		return nc.err
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-s.done:
+		return ErrStopped
+	}
+}
+
+func (s *EtcdServer) AuthInfoFromCtx(ctx context.Context) (*auth.AuthInfo, error) {
+	authInfo, err := s.AuthStore().AuthInfoFromCtx(ctx)
+	if authInfo != nil || err != nil {
+		return authInfo, err
+	}
+	if !s.Cfg.ClientCertAuthEnabled {
+		return nil, nil
+	}
+	authInfo = s.AuthStore().AuthInfoFromTLS(ctx)
+	return authInfo, nil
+
+}
diff --git a/vendor/go.etcd.io/etcd/lease/doc.go b/vendor/go.etcd.io/etcd/lease/doc.go
new file mode 100644
index 0000000..a74eaf7
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package lease provides an interface and implementation for time-limited leases over arbitrary resources.
+package lease
diff --git a/vendor/go.etcd.io/etcd/lease/lease_queue.go b/vendor/go.etcd.io/etcd/lease/lease_queue.go
new file mode 100644
index 0000000..17ddb35
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/lease_queue.go
@@ -0,0 +1,106 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package lease
+
+import "container/heap"
+
+// LeaseWithTime contains lease object with a time.
+// For the lessor's lease heap, time identifies the lease expiration time.
+// For the lessor's lease checkpoint heap, the time identifies the next lease checkpoint time.
+type LeaseWithTime struct {
+	id LeaseID
+	// Unix nanos timestamp.
+	time  int64
+	index int
+}
+
+type LeaseQueue []*LeaseWithTime
+
+func (pq LeaseQueue) Len() int { return len(pq) }
+
+func (pq LeaseQueue) Less(i, j int) bool {
+	return pq[i].time < pq[j].time
+}
+
+func (pq LeaseQueue) Swap(i, j int) {
+	pq[i], pq[j] = pq[j], pq[i]
+	pq[i].index = i
+	pq[j].index = j
+}
+
+func (pq *LeaseQueue) Push(x interface{}) {
+	n := len(*pq)
+	item := x.(*LeaseWithTime)
+	item.index = n
+	*pq = append(*pq, item)
+}
+
+func (pq *LeaseQueue) Pop() interface{} {
+	old := *pq
+	n := len(old)
+	item := old[n-1]
+	item.index = -1 // for safety
+	*pq = old[0 : n-1]
+	return item
+}
+
+// LeaseExpiredNotifier is a queue used to notify lessor to revoke expired lease.
+// Only save one item for a lease, `Register` will update time of the corresponding lease.
+type LeaseExpiredNotifier struct {
+	m     map[LeaseID]*LeaseWithTime
+	queue LeaseQueue
+}
+
+func newLeaseExpiredNotifier() *LeaseExpiredNotifier {
+	return &LeaseExpiredNotifier{
+		m:     make(map[LeaseID]*LeaseWithTime),
+		queue: make(LeaseQueue, 0),
+	}
+}
+
+func (mq *LeaseExpiredNotifier) Init() {
+	heap.Init(&mq.queue)
+	mq.m = make(map[LeaseID]*LeaseWithTime)
+	for _, item := range mq.queue {
+		mq.m[item.id] = item
+	}
+}
+
+func (mq *LeaseExpiredNotifier) RegisterOrUpdate(item *LeaseWithTime) {
+	if old, ok := mq.m[item.id]; ok {
+		old.time = item.time
+		heap.Fix(&mq.queue, old.index)
+	} else {
+		heap.Push(&mq.queue, item)
+		mq.m[item.id] = item
+	}
+}
+
+func (mq *LeaseExpiredNotifier) Unregister() *LeaseWithTime {
+	item := heap.Pop(&mq.queue).(*LeaseWithTime)
+	delete(mq.m, item.id)
+	return item
+}
+
+func (mq *LeaseExpiredNotifier) Poll() *LeaseWithTime {
+	if mq.Len() == 0 {
+		return nil
+	}
+	return mq.queue[0]
+}
+
+func (mq *LeaseExpiredNotifier) Len() int {
+	return len(mq.m)
+}
diff --git a/vendor/go.etcd.io/etcd/lease/leasehttp/doc.go b/vendor/go.etcd.io/etcd/lease/leasehttp/doc.go
new file mode 100644
index 0000000..8177a37
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/leasehttp/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package leasehttp serves lease renewals made through HTTP requests.
+package leasehttp
diff --git a/vendor/go.etcd.io/etcd/lease/leasehttp/http.go b/vendor/go.etcd.io/etcd/lease/leasehttp/http.go
new file mode 100644
index 0000000..67e916d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/leasehttp/http.go
@@ -0,0 +1,248 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package leasehttp
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/lease/leasepb"
+	"go.etcd.io/etcd/pkg/httputil"
+)
+
+var (
+	LeasePrefix         = "/leases"
+	LeaseInternalPrefix = "/leases/internal"
+	applyTimeout        = time.Second
+	ErrLeaseHTTPTimeout = errors.New("waiting for node to catch up its applied index has timed out")
+)
+
+// NewHandler returns an http Handler for lease renewals
+func NewHandler(l lease.Lessor, waitch func() <-chan struct{}) http.Handler {
+	return &leaseHandler{l, waitch}
+}
+
+type leaseHandler struct {
+	l      lease.Lessor
+	waitch func() <-chan struct{}
+}
+
+func (h *leaseHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	defer r.Body.Close()
+	b, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		http.Error(w, "error reading body", http.StatusBadRequest)
+		return
+	}
+
+	var v []byte
+	switch r.URL.Path {
+	case LeasePrefix:
+		lreq := pb.LeaseKeepAliveRequest{}
+		if uerr := lreq.Unmarshal(b); uerr != nil {
+			http.Error(w, "error unmarshalling request", http.StatusBadRequest)
+			return
+		}
+		select {
+		case <-h.waitch():
+		case <-time.After(applyTimeout):
+			http.Error(w, ErrLeaseHTTPTimeout.Error(), http.StatusRequestTimeout)
+			return
+		}
+		ttl, rerr := h.l.Renew(lease.LeaseID(lreq.ID))
+		if rerr != nil {
+			if rerr == lease.ErrLeaseNotFound {
+				http.Error(w, rerr.Error(), http.StatusNotFound)
+				return
+			}
+
+			http.Error(w, rerr.Error(), http.StatusBadRequest)
+			return
+		}
+		// TODO: fill out ResponseHeader
+		resp := &pb.LeaseKeepAliveResponse{ID: lreq.ID, TTL: ttl}
+		v, err = resp.Marshal()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+	case LeaseInternalPrefix:
+		lreq := leasepb.LeaseInternalRequest{}
+		if lerr := lreq.Unmarshal(b); lerr != nil {
+			http.Error(w, "error unmarshalling request", http.StatusBadRequest)
+			return
+		}
+		select {
+		case <-h.waitch():
+		case <-time.After(applyTimeout):
+			http.Error(w, ErrLeaseHTTPTimeout.Error(), http.StatusRequestTimeout)
+			return
+		}
+		l := h.l.Lookup(lease.LeaseID(lreq.LeaseTimeToLiveRequest.ID))
+		if l == nil {
+			http.Error(w, lease.ErrLeaseNotFound.Error(), http.StatusNotFound)
+			return
+		}
+		// TODO: fill out ResponseHeader
+		resp := &leasepb.LeaseInternalResponse{
+			LeaseTimeToLiveResponse: &pb.LeaseTimeToLiveResponse{
+				Header:     &pb.ResponseHeader{},
+				ID:         lreq.LeaseTimeToLiveRequest.ID,
+				TTL:        int64(l.Remaining().Seconds()),
+				GrantedTTL: l.TTL(),
+			},
+		}
+		if lreq.LeaseTimeToLiveRequest.Keys {
+			ks := l.Keys()
+			kbs := make([][]byte, len(ks))
+			for i := range ks {
+				kbs[i] = []byte(ks[i])
+			}
+			resp.LeaseTimeToLiveResponse.Keys = kbs
+		}
+
+		v, err = resp.Marshal()
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+	default:
+		http.Error(w, fmt.Sprintf("unknown request path %q", r.URL.Path), http.StatusBadRequest)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/protobuf")
+	w.Write(v)
+}
+
+// RenewHTTP renews a lease at a given primary server.
+// TODO: Batch request in future?
+func RenewHTTP(ctx context.Context, id lease.LeaseID, url string, rt http.RoundTripper) (int64, error) {
+	// will post lreq protobuf to leader
+	lreq, err := (&pb.LeaseKeepAliveRequest{ID: int64(id)}).Marshal()
+	if err != nil {
+		return -1, err
+	}
+
+	cc := &http.Client{Transport: rt}
+	req, err := http.NewRequest("POST", url, bytes.NewReader(lreq))
+	if err != nil {
+		return -1, err
+	}
+	req.Header.Set("Content-Type", "application/protobuf")
+	req.Cancel = ctx.Done()
+
+	resp, err := cc.Do(req)
+	if err != nil {
+		return -1, err
+	}
+	b, err := readResponse(resp)
+	if err != nil {
+		return -1, err
+	}
+
+	if resp.StatusCode == http.StatusRequestTimeout {
+		return -1, ErrLeaseHTTPTimeout
+	}
+
+	if resp.StatusCode == http.StatusNotFound {
+		return -1, lease.ErrLeaseNotFound
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return -1, fmt.Errorf("lease: unknown error(%s)", string(b))
+	}
+
+	lresp := &pb.LeaseKeepAliveResponse{}
+	if err := lresp.Unmarshal(b); err != nil {
+		return -1, fmt.Errorf(`lease: %v. data = "%s"`, err, string(b))
+	}
+	if lresp.ID != int64(id) {
+		return -1, fmt.Errorf("lease: renew id mismatch")
+	}
+	return lresp.TTL, nil
+}
+
+// TimeToLiveHTTP retrieves lease information of the given lease ID.
+func TimeToLiveHTTP(ctx context.Context, id lease.LeaseID, keys bool, url string, rt http.RoundTripper) (*leasepb.LeaseInternalResponse, error) {
+	// will post lreq protobuf to leader
+	lreq, err := (&leasepb.LeaseInternalRequest{
+		LeaseTimeToLiveRequest: &pb.LeaseTimeToLiveRequest{
+			ID:   int64(id),
+			Keys: keys,
+		},
+	}).Marshal()
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewReader(lreq))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/protobuf")
+
+	req = req.WithContext(ctx)
+
+	cc := &http.Client{Transport: rt}
+	var b []byte
+	// buffer errc channel so that errc don't block inside the go routinue
+	resp, err := cc.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	b, err = readResponse(resp)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode == http.StatusRequestTimeout {
+		return nil, ErrLeaseHTTPTimeout
+	}
+	if resp.StatusCode == http.StatusNotFound {
+		return nil, lease.ErrLeaseNotFound
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("lease: unknown error(%s)", string(b))
+	}
+
+	lresp := &leasepb.LeaseInternalResponse{}
+	if err := lresp.Unmarshal(b); err != nil {
+		return nil, fmt.Errorf(`lease: %v. data = "%s"`, err, string(b))
+	}
+	if lresp.LeaseTimeToLiveResponse.ID != int64(id) {
+		return nil, fmt.Errorf("lease: renew id mismatch")
+	}
+	return lresp, nil
+}
+
+func readResponse(resp *http.Response) (b []byte, err error) {
+	b, err = ioutil.ReadAll(resp.Body)
+	httputil.GracefulClose(resp)
+	return
+}
diff --git a/vendor/go.etcd.io/etcd/lease/leasepb/lease.pb.go b/vendor/go.etcd.io/etcd/lease/leasepb/lease.pb.go
new file mode 100644
index 0000000..16637ee
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/leasepb/lease.pb.go
@@ -0,0 +1,620 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: lease.proto
+
+/*
+	Package leasepb is a generated protocol buffer package.
+
+	It is generated from these files:
+		lease.proto
+
+	It has these top-level messages:
+		Lease
+		LeaseInternalRequest
+		LeaseInternalResponse
+*/
+package leasepb
+
+import (
+	"fmt"
+
+	proto "github.com/golang/protobuf/proto"
+
+	math "math"
+
+	_ "github.com/gogo/protobuf/gogoproto"
+
+	etcdserverpb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	io "io"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type Lease struct {
+	ID           int64 `protobuf:"varint,1,opt,name=ID,proto3" json:"ID,omitempty"`
+	TTL          int64 `protobuf:"varint,2,opt,name=TTL,proto3" json:"TTL,omitempty"`
+	RemainingTTL int64 `protobuf:"varint,3,opt,name=RemainingTTL,proto3" json:"RemainingTTL,omitempty"`
+}
+
+func (m *Lease) Reset()                    { *m = Lease{} }
+func (m *Lease) String() string            { return proto.CompactTextString(m) }
+func (*Lease) ProtoMessage()               {}
+func (*Lease) Descriptor() ([]byte, []int) { return fileDescriptorLease, []int{0} }
+
+type LeaseInternalRequest struct {
+	LeaseTimeToLiveRequest *etcdserverpb.LeaseTimeToLiveRequest `protobuf:"bytes,1,opt,name=LeaseTimeToLiveRequest" json:"LeaseTimeToLiveRequest,omitempty"`
+}
+
+func (m *LeaseInternalRequest) Reset()                    { *m = LeaseInternalRequest{} }
+func (m *LeaseInternalRequest) String() string            { return proto.CompactTextString(m) }
+func (*LeaseInternalRequest) ProtoMessage()               {}
+func (*LeaseInternalRequest) Descriptor() ([]byte, []int) { return fileDescriptorLease, []int{1} }
+
+type LeaseInternalResponse struct {
+	LeaseTimeToLiveResponse *etcdserverpb.LeaseTimeToLiveResponse `protobuf:"bytes,1,opt,name=LeaseTimeToLiveResponse" json:"LeaseTimeToLiveResponse,omitempty"`
+}
+
+func (m *LeaseInternalResponse) Reset()                    { *m = LeaseInternalResponse{} }
+func (m *LeaseInternalResponse) String() string            { return proto.CompactTextString(m) }
+func (*LeaseInternalResponse) ProtoMessage()               {}
+func (*LeaseInternalResponse) Descriptor() ([]byte, []int) { return fileDescriptorLease, []int{2} }
+
+func init() {
+	proto.RegisterType((*Lease)(nil), "leasepb.Lease")
+	proto.RegisterType((*LeaseInternalRequest)(nil), "leasepb.LeaseInternalRequest")
+	proto.RegisterType((*LeaseInternalResponse)(nil), "leasepb.LeaseInternalResponse")
+}
+func (m *Lease) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Lease) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.ID != 0 {
+		dAtA[i] = 0x8
+		i++
+		i = encodeVarintLease(dAtA, i, uint64(m.ID))
+	}
+	if m.TTL != 0 {
+		dAtA[i] = 0x10
+		i++
+		i = encodeVarintLease(dAtA, i, uint64(m.TTL))
+	}
+	if m.RemainingTTL != 0 {
+		dAtA[i] = 0x18
+		i++
+		i = encodeVarintLease(dAtA, i, uint64(m.RemainingTTL))
+	}
+	return i, nil
+}
+
+func (m *LeaseInternalRequest) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LeaseInternalRequest) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.LeaseTimeToLiveRequest != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintLease(dAtA, i, uint64(m.LeaseTimeToLiveRequest.Size()))
+		n1, err := m.LeaseTimeToLiveRequest.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n1
+	}
+	return i, nil
+}
+
+func (m *LeaseInternalResponse) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *LeaseInternalResponse) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	if m.LeaseTimeToLiveResponse != nil {
+		dAtA[i] = 0xa
+		i++
+		i = encodeVarintLease(dAtA, i, uint64(m.LeaseTimeToLiveResponse.Size()))
+		n2, err := m.LeaseTimeToLiveResponse.MarshalTo(dAtA[i:])
+		if err != nil {
+			return 0, err
+		}
+		i += n2
+	}
+	return i, nil
+}
+
+func encodeVarintLease(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *Lease) Size() (n int) {
+	var l int
+	_ = l
+	if m.ID != 0 {
+		n += 1 + sovLease(uint64(m.ID))
+	}
+	if m.TTL != 0 {
+		n += 1 + sovLease(uint64(m.TTL))
+	}
+	if m.RemainingTTL != 0 {
+		n += 1 + sovLease(uint64(m.RemainingTTL))
+	}
+	return n
+}
+
+func (m *LeaseInternalRequest) Size() (n int) {
+	var l int
+	_ = l
+	if m.LeaseTimeToLiveRequest != nil {
+		l = m.LeaseTimeToLiveRequest.Size()
+		n += 1 + l + sovLease(uint64(l))
+	}
+	return n
+}
+
+func (m *LeaseInternalResponse) Size() (n int) {
+	var l int
+	_ = l
+	if m.LeaseTimeToLiveResponse != nil {
+		l = m.LeaseTimeToLiveResponse.Size()
+		n += 1 + l + sovLease(uint64(l))
+	}
+	return n
+}
+
+func sovLease(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozLease(x uint64) (n int) {
+	return sovLease(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *Lease) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowLease
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: Lease: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Lease: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field ID", wireType)
+			}
+			m.ID = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.ID |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field TTL", wireType)
+			}
+			m.TTL = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.TTL |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 3:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field RemainingTTL", wireType)
+			}
+			m.RemainingTTL = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.RemainingTTL |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipLease(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthLease
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LeaseInternalRequest) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowLease
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LeaseInternalRequest: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LeaseInternalRequest: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field LeaseTimeToLiveRequest", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthLease
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.LeaseTimeToLiveRequest == nil {
+				m.LeaseTimeToLiveRequest = &etcdserverpb.LeaseTimeToLiveRequest{}
+			}
+			if err := m.LeaseTimeToLiveRequest.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipLease(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthLease
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *LeaseInternalResponse) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowLease
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: LeaseInternalResponse: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: LeaseInternalResponse: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field LeaseTimeToLiveResponse", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthLease
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			if m.LeaseTimeToLiveResponse == nil {
+				m.LeaseTimeToLiveResponse = &etcdserverpb.LeaseTimeToLiveResponse{}
+			}
+			if err := m.LeaseTimeToLiveResponse.Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipLease(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthLease
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipLease(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowLease
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowLease
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthLease
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowLease
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipLease(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthLease = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowLease   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("lease.proto", fileDescriptorLease) }
+
+var fileDescriptorLease = []byte{
+	// 253 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0xce, 0x49, 0x4d, 0x2c,
+	0x4e, 0xd5, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x07, 0x73, 0x0a, 0x92, 0xa4, 0x44, 0xd2,
+	0xf3, 0xd3, 0xf3, 0xc1, 0x62, 0xfa, 0x20, 0x16, 0x44, 0x5a, 0x4a, 0x2d, 0xb5, 0x24, 0x39, 0x45,
+	0x1f, 0x44, 0x14, 0xa7, 0x16, 0x95, 0xa5, 0x16, 0x21, 0x31, 0x0b, 0x92, 0xf4, 0x8b, 0x0a, 0x92,
+	0x21, 0xea, 0x94, 0x7c, 0xb9, 0x58, 0x7d, 0x40, 0x06, 0x09, 0xf1, 0x71, 0x31, 0x79, 0xba, 0x48,
+	0x30, 0x2a, 0x30, 0x6a, 0x30, 0x07, 0x31, 0x79, 0xba, 0x08, 0x09, 0x70, 0x31, 0x87, 0x84, 0xf8,
+	0x48, 0x30, 0x81, 0x05, 0x40, 0x4c, 0x21, 0x25, 0x2e, 0x9e, 0xa0, 0xd4, 0xdc, 0xc4, 0xcc, 0xbc,
+	0xcc, 0xbc, 0x74, 0x90, 0x14, 0x33, 0x58, 0x0a, 0x45, 0x4c, 0xa9, 0x84, 0x4b, 0x04, 0x6c, 0x9c,
+	0x67, 0x5e, 0x49, 0x6a, 0x51, 0x5e, 0x62, 0x4e, 0x50, 0x6a, 0x61, 0x69, 0x6a, 0x71, 0x89, 0x50,
+	0x0c, 0x97, 0x18, 0x58, 0x3c, 0x24, 0x33, 0x37, 0x35, 0x24, 0xdf, 0x27, 0xb3, 0x2c, 0x15, 0x2a,
+	0x03, 0xb6, 0x91, 0xdb, 0x48, 0x45, 0x0f, 0xd9, 0x7d, 0x7a, 0xd8, 0xd5, 0x06, 0xe1, 0x30, 0x43,
+	0xa9, 0x82, 0x4b, 0x14, 0xcd, 0xd6, 0xe2, 0x82, 0xfc, 0xbc, 0xe2, 0x54, 0xa1, 0x78, 0x2e, 0x71,
+	0x0c, 0x2d, 0x10, 0x29, 0xa8, 0xbd, 0xaa, 0x04, 0xec, 0x85, 0x28, 0x0e, 0xc2, 0x65, 0x8a, 0x93,
+	0xc4, 0x89, 0x87, 0x72, 0x0c, 0x17, 0x1e, 0xca, 0x31, 0x9c, 0x78, 0x24, 0xc7, 0x78, 0xe1, 0x91,
+	0x1c, 0xe3, 0x83, 0x47, 0x72, 0x8c, 0x33, 0x1e, 0xcb, 0x31, 0x24, 0xb1, 0x81, 0xc3, 0xd7, 0x18,
+	0x10, 0x00, 0x00, 0xff, 0xff, 0xa9, 0x9f, 0x8b, 0x6c, 0xb5, 0x01, 0x00, 0x00,
+}
diff --git a/vendor/go.etcd.io/etcd/lease/leasepb/lease.proto b/vendor/go.etcd.io/etcd/lease/leasepb/lease.proto
new file mode 100644
index 0000000..1169d9f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/leasepb/lease.proto
@@ -0,0 +1,25 @@
+syntax = "proto3";
+package leasepb;
+
+import "gogoproto/gogo.proto";
+import "etcd/etcdserver/etcdserverpb/rpc.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_getters_all) = false;
+option (gogoproto.goproto_enum_prefix_all) = false;
+
+message Lease {
+  int64 ID = 1;
+  int64 TTL = 2;
+  int64 RemainingTTL = 3;
+}
+
+message LeaseInternalRequest {
+  etcdserverpb.LeaseTimeToLiveRequest LeaseTimeToLiveRequest = 1;
+}
+
+message LeaseInternalResponse {
+  etcdserverpb.LeaseTimeToLiveResponse LeaseTimeToLiveResponse = 1;
+}
diff --git a/vendor/go.etcd.io/etcd/lease/lessor.go b/vendor/go.etcd.io/etcd/lease/lessor.go
new file mode 100644
index 0000000..cc20283
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/lessor.go
@@ -0,0 +1,933 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package lease
+
+import (
+	"container/heap"
+	"context"
+	"encoding/binary"
+	"errors"
+	"math"
+	"sort"
+	"sync"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease/leasepb"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.uber.org/zap"
+)
+
+// NoLease is a special LeaseID representing the absence of a lease.
+const NoLease = LeaseID(0)
+
+// MaxLeaseTTL is the maximum lease TTL value
+const MaxLeaseTTL = 9000000000
+
+var (
+	forever = time.Time{}
+
+	leaseBucketName = []byte("lease")
+
+	// maximum number of leases to revoke per second; configurable for tests
+	leaseRevokeRate = 1000
+
+	// maximum number of lease checkpoints recorded to the consensus log per second; configurable for tests
+	leaseCheckpointRate = 1000
+
+	// the default interval of lease checkpoint
+	defaultLeaseCheckpointInterval = 5 * time.Minute
+
+	// maximum number of lease checkpoints to batch into a single consensus log entry
+	maxLeaseCheckpointBatchSize = 1000
+
+	// the default interval to check if the expired lease is revoked
+	defaultExpiredleaseRetryInterval = 3 * time.Second
+
+	ErrNotPrimary       = errors.New("not a primary lessor")
+	ErrLeaseNotFound    = errors.New("lease not found")
+	ErrLeaseExists      = errors.New("lease already exists")
+	ErrLeaseTTLTooLarge = errors.New("too large lease TTL")
+)
+
+// TxnDelete is a TxnWrite that only permits deletes. Defined here
+// to avoid circular dependency with mvcc.
+type TxnDelete interface {
+	DeleteRange(key, end []byte) (n, rev int64)
+	End()
+}
+
+// RangeDeleter is a TxnDelete constructor.
+type RangeDeleter func() TxnDelete
+
+// Checkpointer permits checkpointing of lease remaining TTLs to the consensus log. Defined here to
+// avoid circular dependency with mvcc.
+type Checkpointer func(ctx context.Context, lc *pb.LeaseCheckpointRequest)
+
+type LeaseID int64
+
+// Lessor owns leases. It can grant, revoke, renew and modify leases for lessee.
+type Lessor interface {
+	// SetRangeDeleter lets the lessor create TxnDeletes to the store.
+	// Lessor deletes the items in the revoked or expired lease by creating
+	// new TxnDeletes.
+	SetRangeDeleter(rd RangeDeleter)
+
+	SetCheckpointer(cp Checkpointer)
+
+	// Grant grants a lease that expires at least after TTL seconds.
+	Grant(id LeaseID, ttl int64) (*Lease, error)
+	// Revoke revokes a lease with given ID. The item attached to the
+	// given lease will be removed. If the ID does not exist, an error
+	// will be returned.
+	Revoke(id LeaseID) error
+
+	// Checkpoint applies the remainingTTL of a lease. The remainingTTL is used in Promote to set
+	// the expiry of leases to less than the full TTL when possible.
+	Checkpoint(id LeaseID, remainingTTL int64) error
+
+	// Attach attaches given leaseItem to the lease with given LeaseID.
+	// If the lease does not exist, an error will be returned.
+	Attach(id LeaseID, items []LeaseItem) error
+
+	// GetLease returns LeaseID for given item.
+	// If no lease found, NoLease value will be returned.
+	GetLease(item LeaseItem) LeaseID
+
+	// Detach detaches given leaseItem from the lease with given LeaseID.
+	// If the lease does not exist, an error will be returned.
+	Detach(id LeaseID, items []LeaseItem) error
+
+	// Promote promotes the lessor to be the primary lessor. Primary lessor manages
+	// the expiration and renew of leases.
+	// Newly promoted lessor renew the TTL of all lease to extend + previous TTL.
+	Promote(extend time.Duration)
+
+	// Demote demotes the lessor from being the primary lessor.
+	Demote()
+
+	// Renew renews a lease with given ID. It returns the renewed TTL. If the ID does not exist,
+	// an error will be returned.
+	Renew(id LeaseID) (int64, error)
+
+	// Lookup gives the lease at a given lease id, if any
+	Lookup(id LeaseID) *Lease
+
+	// Leases lists all leases.
+	Leases() []*Lease
+
+	// ExpiredLeasesC returns a chan that is used to receive expired leases.
+	ExpiredLeasesC() <-chan []*Lease
+
+	// Recover recovers the lessor state from the given backend and RangeDeleter.
+	Recover(b backend.Backend, rd RangeDeleter)
+
+	// Stop stops the lessor for managing leases. The behavior of calling Stop multiple
+	// times is undefined.
+	Stop()
+}
+
+// lessor implements Lessor interface.
+// TODO: use clockwork for testability.
+type lessor struct {
+	mu sync.RWMutex
+
+	// demotec is set when the lessor is the primary.
+	// demotec will be closed if the lessor is demoted.
+	demotec chan struct{}
+
+	leaseMap             map[LeaseID]*Lease
+	leaseExpiredNotifier *LeaseExpiredNotifier
+	leaseCheckpointHeap  LeaseQueue
+	itemMap              map[LeaseItem]LeaseID
+
+	// When a lease expires, the lessor will delete the
+	// leased range (or key) by the RangeDeleter.
+	rd RangeDeleter
+
+	// When a lease's deadline should be persisted to preserve the remaining TTL across leader
+	// elections and restarts, the lessor will checkpoint the lease by the Checkpointer.
+	cp Checkpointer
+
+	// backend to persist leases. We only persist lease ID and expiry for now.
+	// The leased items can be recovered by iterating all the keys in kv.
+	b backend.Backend
+
+	// minLeaseTTL is the minimum lease TTL that can be granted for a lease. Any
+	// requests for shorter TTLs are extended to the minimum TTL.
+	minLeaseTTL int64
+
+	expiredC chan []*Lease
+	// stopC is a channel whose closure indicates that the lessor should be stopped.
+	stopC chan struct{}
+	// doneC is a channel whose closure indicates that the lessor is stopped.
+	doneC chan struct{}
+
+	lg *zap.Logger
+
+	// Wait duration between lease checkpoints.
+	checkpointInterval time.Duration
+	// the interval to check if the expired lease is revoked
+	expiredLeaseRetryInterval time.Duration
+}
+
+type LessorConfig struct {
+	MinLeaseTTL                int64
+	CheckpointInterval         time.Duration
+	ExpiredLeasesRetryInterval time.Duration
+}
+
+func NewLessor(lg *zap.Logger, b backend.Backend, cfg LessorConfig) Lessor {
+	return newLessor(lg, b, cfg)
+}
+
+func newLessor(lg *zap.Logger, b backend.Backend, cfg LessorConfig) *lessor {
+	checkpointInterval := cfg.CheckpointInterval
+	expiredLeaseRetryInterval := cfg.ExpiredLeasesRetryInterval
+	if checkpointInterval == 0 {
+		checkpointInterval = defaultLeaseCheckpointInterval
+	}
+	if expiredLeaseRetryInterval == 0 {
+		expiredLeaseRetryInterval = defaultExpiredleaseRetryInterval
+	}
+	l := &lessor{
+		leaseMap:                  make(map[LeaseID]*Lease),
+		itemMap:                   make(map[LeaseItem]LeaseID),
+		leaseExpiredNotifier:      newLeaseExpiredNotifier(),
+		leaseCheckpointHeap:       make(LeaseQueue, 0),
+		b:                         b,
+		minLeaseTTL:               cfg.MinLeaseTTL,
+		checkpointInterval:        checkpointInterval,
+		expiredLeaseRetryInterval: expiredLeaseRetryInterval,
+		// expiredC is a small buffered chan to avoid unnecessary blocking.
+		expiredC: make(chan []*Lease, 16),
+		stopC:    make(chan struct{}),
+		doneC:    make(chan struct{}),
+		lg:       lg,
+	}
+	l.initAndRecover()
+
+	go l.runLoop()
+
+	return l
+}
+
+// isPrimary indicates if this lessor is the primary lessor. The primary
+// lessor manages lease expiration and renew.
+//
+// in etcd, raft leader is the primary. Thus there might be two primary
+// leaders at the same time (raft allows concurrent leader but with different term)
+// for at most a leader election timeout.
+// The old primary leader cannot affect the correctness since its proposal has a
+// smaller term and will not be committed.
+//
+// TODO: raft follower do not forward lease management proposals. There might be a
+// very small window (within second normally which depends on go scheduling) that
+// a raft follow is the primary between the raft leader demotion and lessor demotion.
+// Usually this should not be a problem. Lease should not be that sensitive to timing.
+func (le *lessor) isPrimary() bool {
+	return le.demotec != nil
+}
+
+func (le *lessor) SetRangeDeleter(rd RangeDeleter) {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	le.rd = rd
+}
+
+func (le *lessor) SetCheckpointer(cp Checkpointer) {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	le.cp = cp
+}
+
+func (le *lessor) Grant(id LeaseID, ttl int64) (*Lease, error) {
+	if id == NoLease {
+		return nil, ErrLeaseNotFound
+	}
+
+	if ttl > MaxLeaseTTL {
+		return nil, ErrLeaseTTLTooLarge
+	}
+
+	// TODO: when lessor is under high load, it should give out lease
+	// with longer TTL to reduce renew load.
+	l := &Lease{
+		ID:      id,
+		ttl:     ttl,
+		itemSet: make(map[LeaseItem]struct{}),
+		revokec: make(chan struct{}),
+	}
+
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	if _, ok := le.leaseMap[id]; ok {
+		return nil, ErrLeaseExists
+	}
+
+	if l.ttl < le.minLeaseTTL {
+		l.ttl = le.minLeaseTTL
+	}
+
+	if le.isPrimary() {
+		l.refresh(0)
+	} else {
+		l.forever()
+	}
+
+	le.leaseMap[id] = l
+	item := &LeaseWithTime{id: l.ID, time: l.expiry.UnixNano()}
+	le.leaseExpiredNotifier.RegisterOrUpdate(item)
+	l.persistTo(le.b)
+
+	leaseTotalTTLs.Observe(float64(l.ttl))
+	leaseGranted.Inc()
+
+	if le.isPrimary() {
+		le.scheduleCheckpointIfNeeded(l)
+	}
+
+	return l, nil
+}
+
+func (le *lessor) Revoke(id LeaseID) error {
+	le.mu.Lock()
+
+	l := le.leaseMap[id]
+	if l == nil {
+		le.mu.Unlock()
+		return ErrLeaseNotFound
+	}
+	defer close(l.revokec)
+	// unlock before doing external work
+	le.mu.Unlock()
+
+	if le.rd == nil {
+		return nil
+	}
+
+	txn := le.rd()
+
+	// sort keys so deletes are in same order among all members,
+	// otherwise the backend hashes will be different
+	keys := l.Keys()
+	sort.StringSlice(keys).Sort()
+	for _, key := range keys {
+		txn.DeleteRange([]byte(key), nil)
+	}
+
+	le.mu.Lock()
+	defer le.mu.Unlock()
+	delete(le.leaseMap, l.ID)
+	// lease deletion needs to be in the same backend transaction with the
+	// kv deletion. Or we might end up with not executing the revoke or not
+	// deleting the keys if etcdserver fails in between.
+	le.b.BatchTx().UnsafeDelete(leaseBucketName, int64ToBytes(int64(l.ID)))
+
+	txn.End()
+
+	leaseRevoked.Inc()
+	return nil
+}
+
+func (le *lessor) Checkpoint(id LeaseID, remainingTTL int64) error {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	if l, ok := le.leaseMap[id]; ok {
+		// when checkpointing, we only update the remainingTTL, Promote is responsible for applying this to lease expiry
+		l.remainingTTL = remainingTTL
+		if le.isPrimary() {
+			// schedule the next checkpoint as needed
+			le.scheduleCheckpointIfNeeded(l)
+		}
+	}
+	return nil
+}
+
+// Renew renews an existing lease. If the given lease does not exist or
+// has expired, an error will be returned.
+func (le *lessor) Renew(id LeaseID) (int64, error) {
+	le.mu.RLock()
+	if !le.isPrimary() {
+		// forward renew request to primary instead of returning error.
+		le.mu.RUnlock()
+		return -1, ErrNotPrimary
+	}
+
+	demotec := le.demotec
+
+	l := le.leaseMap[id]
+	if l == nil {
+		le.mu.RUnlock()
+		return -1, ErrLeaseNotFound
+	}
+	// Clear remaining TTL when we renew if it is set
+	clearRemainingTTL := le.cp != nil && l.remainingTTL > 0
+
+	le.mu.RUnlock()
+	if l.expired() {
+		select {
+		// A expired lease might be pending for revoking or going through
+		// quorum to be revoked. To be accurate, renew request must wait for the
+		// deletion to complete.
+		case <-l.revokec:
+			return -1, ErrLeaseNotFound
+		// The expired lease might fail to be revoked if the primary changes.
+		// The caller will retry on ErrNotPrimary.
+		case <-demotec:
+			return -1, ErrNotPrimary
+		case <-le.stopC:
+			return -1, ErrNotPrimary
+		}
+	}
+
+	// Clear remaining TTL when we renew if it is set
+	// By applying a RAFT entry only when the remainingTTL is already set, we limit the number
+	// of RAFT entries written per lease to a max of 2 per checkpoint interval.
+	if clearRemainingTTL {
+		le.cp(context.Background(), &pb.LeaseCheckpointRequest{Checkpoints: []*pb.LeaseCheckpoint{{ID: int64(l.ID), Remaining_TTL: 0}}})
+	}
+
+	le.mu.Lock()
+	l.refresh(0)
+	item := &LeaseWithTime{id: l.ID, time: l.expiry.UnixNano()}
+	le.leaseExpiredNotifier.RegisterOrUpdate(item)
+	le.mu.Unlock()
+
+	leaseRenewed.Inc()
+	return l.ttl, nil
+}
+
+func (le *lessor) Lookup(id LeaseID) *Lease {
+	le.mu.RLock()
+	defer le.mu.RUnlock()
+	return le.leaseMap[id]
+}
+
+func (le *lessor) unsafeLeases() []*Lease {
+	leases := make([]*Lease, 0, len(le.leaseMap))
+	for _, l := range le.leaseMap {
+		leases = append(leases, l)
+	}
+	return leases
+}
+
+func (le *lessor) Leases() []*Lease {
+	le.mu.RLock()
+	ls := le.unsafeLeases()
+	le.mu.RUnlock()
+	sort.Sort(leasesByExpiry(ls))
+	return ls
+}
+
+func (le *lessor) Promote(extend time.Duration) {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	le.demotec = make(chan struct{})
+
+	// refresh the expiries of all leases.
+	for _, l := range le.leaseMap {
+		l.refresh(extend)
+		item := &LeaseWithTime{id: l.ID, time: l.expiry.UnixNano()}
+		le.leaseExpiredNotifier.RegisterOrUpdate(item)
+	}
+
+	if len(le.leaseMap) < leaseRevokeRate {
+		// no possibility of lease pile-up
+		return
+	}
+
+	// adjust expiries in case of overlap
+	leases := le.unsafeLeases()
+	sort.Sort(leasesByExpiry(leases))
+
+	baseWindow := leases[0].Remaining()
+	nextWindow := baseWindow + time.Second
+	expires := 0
+	// have fewer expires than the total revoke rate so piled up leases
+	// don't consume the entire revoke limit
+	targetExpiresPerSecond := (3 * leaseRevokeRate) / 4
+	for _, l := range leases {
+		remaining := l.Remaining()
+		if remaining > nextWindow {
+			baseWindow = remaining
+			nextWindow = baseWindow + time.Second
+			expires = 1
+			continue
+		}
+		expires++
+		if expires <= targetExpiresPerSecond {
+			continue
+		}
+		rateDelay := float64(time.Second) * (float64(expires) / float64(targetExpiresPerSecond))
+		// If leases are extended by n seconds, leases n seconds ahead of the
+		// base window should be extended by only one second.
+		rateDelay -= float64(remaining - baseWindow)
+		delay := time.Duration(rateDelay)
+		nextWindow = baseWindow + delay
+		l.refresh(delay + extend)
+		item := &LeaseWithTime{id: l.ID, time: l.expiry.UnixNano()}
+		le.leaseExpiredNotifier.RegisterOrUpdate(item)
+		le.scheduleCheckpointIfNeeded(l)
+	}
+}
+
+type leasesByExpiry []*Lease
+
+func (le leasesByExpiry) Len() int           { return len(le) }
+func (le leasesByExpiry) Less(i, j int) bool { return le[i].Remaining() < le[j].Remaining() }
+func (le leasesByExpiry) Swap(i, j int)      { le[i], le[j] = le[j], le[i] }
+
+func (le *lessor) Demote() {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	// set the expiries of all leases to forever
+	for _, l := range le.leaseMap {
+		l.forever()
+	}
+
+	le.clearScheduledLeasesCheckpoints()
+
+	if le.demotec != nil {
+		close(le.demotec)
+		le.demotec = nil
+	}
+}
+
+// Attach attaches items to the lease with given ID. When the lease
+// expires, the attached items will be automatically removed.
+// If the given lease does not exist, an error will be returned.
+func (le *lessor) Attach(id LeaseID, items []LeaseItem) error {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	l := le.leaseMap[id]
+	if l == nil {
+		return ErrLeaseNotFound
+	}
+
+	l.mu.Lock()
+	for _, it := range items {
+		l.itemSet[it] = struct{}{}
+		le.itemMap[it] = id
+	}
+	l.mu.Unlock()
+	return nil
+}
+
+func (le *lessor) GetLease(item LeaseItem) LeaseID {
+	le.mu.RLock()
+	id := le.itemMap[item]
+	le.mu.RUnlock()
+	return id
+}
+
+// Detach detaches items from the lease with given ID.
+// If the given lease does not exist, an error will be returned.
+func (le *lessor) Detach(id LeaseID, items []LeaseItem) error {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	l := le.leaseMap[id]
+	if l == nil {
+		return ErrLeaseNotFound
+	}
+
+	l.mu.Lock()
+	for _, it := range items {
+		delete(l.itemSet, it)
+		delete(le.itemMap, it)
+	}
+	l.mu.Unlock()
+	return nil
+}
+
+func (le *lessor) Recover(b backend.Backend, rd RangeDeleter) {
+	le.mu.Lock()
+	defer le.mu.Unlock()
+
+	le.b = b
+	le.rd = rd
+	le.leaseMap = make(map[LeaseID]*Lease)
+	le.itemMap = make(map[LeaseItem]LeaseID)
+	le.initAndRecover()
+}
+
+func (le *lessor) ExpiredLeasesC() <-chan []*Lease {
+	return le.expiredC
+}
+
+func (le *lessor) Stop() {
+	close(le.stopC)
+	<-le.doneC
+}
+
+func (le *lessor) runLoop() {
+	defer close(le.doneC)
+
+	for {
+		le.revokeExpiredLeases()
+		le.checkpointScheduledLeases()
+
+		select {
+		case <-time.After(500 * time.Millisecond):
+		case <-le.stopC:
+			return
+		}
+	}
+}
+
+// revokeExpiredLeases finds all leases past their expiry and sends them to expired channel for
+// to be revoked.
+func (le *lessor) revokeExpiredLeases() {
+	var ls []*Lease
+
+	// rate limit
+	revokeLimit := leaseRevokeRate / 2
+
+	le.mu.RLock()
+	if le.isPrimary() {
+		ls = le.findExpiredLeases(revokeLimit)
+	}
+	le.mu.RUnlock()
+
+	if len(ls) != 0 {
+		select {
+		case <-le.stopC:
+			return
+		case le.expiredC <- ls:
+		default:
+			// the receiver of expiredC is probably busy handling
+			// other stuff
+			// let's try this next time after 500ms
+		}
+	}
+}
+
+// checkpointScheduledLeases finds all scheduled lease checkpoints that are due and
+// submits them to the checkpointer to persist them to the consensus log.
+func (le *lessor) checkpointScheduledLeases() {
+	var cps []*pb.LeaseCheckpoint
+
+	// rate limit
+	for i := 0; i < leaseCheckpointRate/2; i++ {
+		le.mu.Lock()
+		if le.isPrimary() {
+			cps = le.findDueScheduledCheckpoints(maxLeaseCheckpointBatchSize)
+		}
+		le.mu.Unlock()
+
+		if len(cps) != 0 {
+			le.cp(context.Background(), &pb.LeaseCheckpointRequest{Checkpoints: cps})
+		}
+		if len(cps) < maxLeaseCheckpointBatchSize {
+			return
+		}
+	}
+}
+
+func (le *lessor) clearScheduledLeasesCheckpoints() {
+	le.leaseCheckpointHeap = make(LeaseQueue, 0)
+}
+
+// expireExists returns true if expiry items exist.
+// It pops only when expiry item exists.
+// "next" is true, to indicate that it may exist in next attempt.
+func (le *lessor) expireExists() (l *Lease, ok bool, next bool) {
+	if le.leaseExpiredNotifier.Len() == 0 {
+		return nil, false, false
+	}
+
+	item := le.leaseExpiredNotifier.Poll()
+	l = le.leaseMap[item.id]
+	if l == nil {
+		// lease has expired or been revoked
+		// no need to revoke (nothing is expiry)
+		le.leaseExpiredNotifier.Unregister() // O(log N)
+		return nil, false, true
+	}
+	now := time.Now()
+	if now.UnixNano() < item.time /* expiration time */ {
+		// Candidate expirations are caught up, reinsert this item
+		// and no need to revoke (nothing is expiry)
+		return l, false, false
+	}
+
+	// recheck if revoke is complete after retry interval
+	item.time = now.Add(le.expiredLeaseRetryInterval).UnixNano()
+	le.leaseExpiredNotifier.RegisterOrUpdate(item)
+	return l, true, false
+}
+
+// findExpiredLeases loops leases in the leaseMap until reaching expired limit
+// and returns the expired leases that needed to be revoked.
+func (le *lessor) findExpiredLeases(limit int) []*Lease {
+	leases := make([]*Lease, 0, 16)
+
+	for {
+		l, ok, next := le.expireExists()
+		if !ok && !next {
+			break
+		}
+		if !ok {
+			continue
+		}
+		if next {
+			continue
+		}
+
+		if l.expired() {
+			leases = append(leases, l)
+
+			// reach expired limit
+			if len(leases) == limit {
+				break
+			}
+		}
+	}
+
+	return leases
+}
+
+func (le *lessor) scheduleCheckpointIfNeeded(lease *Lease) {
+	if le.cp == nil {
+		return
+	}
+
+	if lease.RemainingTTL() > int64(le.checkpointInterval.Seconds()) {
+		if le.lg != nil {
+			le.lg.Debug("Scheduling lease checkpoint",
+				zap.Int64("leaseID", int64(lease.ID)),
+				zap.Duration("intervalSeconds", le.checkpointInterval),
+			)
+		}
+		heap.Push(&le.leaseCheckpointHeap, &LeaseWithTime{
+			id:   lease.ID,
+			time: time.Now().Add(le.checkpointInterval).UnixNano(),
+		})
+	}
+}
+
+func (le *lessor) findDueScheduledCheckpoints(checkpointLimit int) []*pb.LeaseCheckpoint {
+	if le.cp == nil {
+		return nil
+	}
+
+	now := time.Now()
+	cps := []*pb.LeaseCheckpoint{}
+	for le.leaseCheckpointHeap.Len() > 0 && len(cps) < checkpointLimit {
+		lt := le.leaseCheckpointHeap[0]
+		if lt.time /* next checkpoint time */ > now.UnixNano() {
+			return cps
+		}
+		heap.Pop(&le.leaseCheckpointHeap)
+		var l *Lease
+		var ok bool
+		if l, ok = le.leaseMap[lt.id]; !ok {
+			continue
+		}
+		if !now.Before(l.expiry) {
+			continue
+		}
+		remainingTTL := int64(math.Ceil(l.expiry.Sub(now).Seconds()))
+		if remainingTTL >= l.ttl {
+			continue
+		}
+		if le.lg != nil {
+			le.lg.Debug("Checkpointing lease",
+				zap.Int64("leaseID", int64(lt.id)),
+				zap.Int64("remainingTTL", remainingTTL),
+			)
+		}
+		cps = append(cps, &pb.LeaseCheckpoint{ID: int64(lt.id), Remaining_TTL: remainingTTL})
+	}
+	return cps
+}
+
+func (le *lessor) initAndRecover() {
+	tx := le.b.BatchTx()
+	tx.Lock()
+
+	tx.UnsafeCreateBucket(leaseBucketName)
+	_, vs := tx.UnsafeRange(leaseBucketName, int64ToBytes(0), int64ToBytes(math.MaxInt64), 0)
+	// TODO: copy vs and do decoding outside tx lock if lock contention becomes an issue.
+	for i := range vs {
+		var lpb leasepb.Lease
+		err := lpb.Unmarshal(vs[i])
+		if err != nil {
+			tx.Unlock()
+			panic("failed to unmarshal lease proto item")
+		}
+		ID := LeaseID(lpb.ID)
+		if lpb.TTL < le.minLeaseTTL {
+			lpb.TTL = le.minLeaseTTL
+		}
+		le.leaseMap[ID] = &Lease{
+			ID:  ID,
+			ttl: lpb.TTL,
+			// itemSet will be filled in when recover key-value pairs
+			// set expiry to forever, refresh when promoted
+			itemSet: make(map[LeaseItem]struct{}),
+			expiry:  forever,
+			revokec: make(chan struct{}),
+		}
+	}
+	le.leaseExpiredNotifier.Init()
+	heap.Init(&le.leaseCheckpointHeap)
+	tx.Unlock()
+
+	le.b.ForceCommit()
+}
+
+type Lease struct {
+	ID           LeaseID
+	ttl          int64 // time to live of the lease in seconds
+	remainingTTL int64 // remaining time to live in seconds, if zero valued it is considered unset and the full ttl should be used
+	// expiryMu protects concurrent accesses to expiry
+	expiryMu sync.RWMutex
+	// expiry is time when lease should expire. no expiration when expiry.IsZero() is true
+	expiry time.Time
+
+	// mu protects concurrent accesses to itemSet
+	mu      sync.RWMutex
+	itemSet map[LeaseItem]struct{}
+	revokec chan struct{}
+}
+
+func (l *Lease) expired() bool {
+	return l.Remaining() <= 0
+}
+
+func (l *Lease) persistTo(b backend.Backend) {
+	key := int64ToBytes(int64(l.ID))
+
+	lpb := leasepb.Lease{ID: int64(l.ID), TTL: l.ttl, RemainingTTL: l.remainingTTL}
+	val, err := lpb.Marshal()
+	if err != nil {
+		panic("failed to marshal lease proto item")
+	}
+
+	b.BatchTx().Lock()
+	b.BatchTx().UnsafePut(leaseBucketName, key, val)
+	b.BatchTx().Unlock()
+}
+
+// TTL returns the TTL of the Lease.
+func (l *Lease) TTL() int64 {
+	return l.ttl
+}
+
+// RemainingTTL returns the last checkpointed remaining TTL of the lease.
+// TODO(jpbetz): do not expose this utility method
+func (l *Lease) RemainingTTL() int64 {
+	if l.remainingTTL > 0 {
+		return l.remainingTTL
+	}
+	return l.ttl
+}
+
+// refresh refreshes the expiry of the lease.
+func (l *Lease) refresh(extend time.Duration) {
+	newExpiry := time.Now().Add(extend + time.Duration(l.RemainingTTL())*time.Second)
+	l.expiryMu.Lock()
+	defer l.expiryMu.Unlock()
+	l.expiry = newExpiry
+}
+
+// forever sets the expiry of lease to be forever.
+func (l *Lease) forever() {
+	l.expiryMu.Lock()
+	defer l.expiryMu.Unlock()
+	l.expiry = forever
+}
+
+// Keys returns all the keys attached to the lease.
+func (l *Lease) Keys() []string {
+	l.mu.RLock()
+	keys := make([]string, 0, len(l.itemSet))
+	for k := range l.itemSet {
+		keys = append(keys, k.Key)
+	}
+	l.mu.RUnlock()
+	return keys
+}
+
+// Remaining returns the remaining time of the lease.
+func (l *Lease) Remaining() time.Duration {
+	l.expiryMu.RLock()
+	defer l.expiryMu.RUnlock()
+	if l.expiry.IsZero() {
+		return time.Duration(math.MaxInt64)
+	}
+	return time.Until(l.expiry)
+}
+
+type LeaseItem struct {
+	Key string
+}
+
+func int64ToBytes(n int64) []byte {
+	bytes := make([]byte, 8)
+	binary.BigEndian.PutUint64(bytes, uint64(n))
+	return bytes
+}
+
+// FakeLessor is a fake implementation of Lessor interface.
+// Used for testing only.
+type FakeLessor struct{}
+
+func (fl *FakeLessor) SetRangeDeleter(dr RangeDeleter) {}
+
+func (fl *FakeLessor) SetCheckpointer(cp Checkpointer) {}
+
+func (fl *FakeLessor) Grant(id LeaseID, ttl int64) (*Lease, error) { return nil, nil }
+
+func (fl *FakeLessor) Revoke(id LeaseID) error { return nil }
+
+func (fl *FakeLessor) Checkpoint(id LeaseID, remainingTTL int64) error { return nil }
+
+func (fl *FakeLessor) Attach(id LeaseID, items []LeaseItem) error { return nil }
+
+func (fl *FakeLessor) GetLease(item LeaseItem) LeaseID            { return 0 }
+func (fl *FakeLessor) Detach(id LeaseID, items []LeaseItem) error { return nil }
+
+func (fl *FakeLessor) Promote(extend time.Duration) {}
+
+func (fl *FakeLessor) Demote() {}
+
+func (fl *FakeLessor) Renew(id LeaseID) (int64, error) { return 10, nil }
+
+func (fl *FakeLessor) Lookup(id LeaseID) *Lease { return nil }
+
+func (fl *FakeLessor) Leases() []*Lease { return nil }
+
+func (fl *FakeLessor) ExpiredLeasesC() <-chan []*Lease { return nil }
+
+func (fl *FakeLessor) Recover(b backend.Backend, rd RangeDeleter) {}
+
+func (fl *FakeLessor) Stop() {}
+
+type FakeTxnDelete struct {
+	backend.BatchTx
+}
+
+func (ftd *FakeTxnDelete) DeleteRange(key, end []byte) (n, rev int64) { return 0, 0 }
+func (ftd *FakeTxnDelete) End()                                       { ftd.Unlock() }
diff --git a/vendor/go.etcd.io/etcd/lease/metrics.go b/vendor/go.etcd.io/etcd/lease/metrics.go
new file mode 100644
index 0000000..06f8b58
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/lease/metrics.go
@@ -0,0 +1,59 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package lease
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	leaseGranted = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "granted_total",
+		Help:      "The total number of granted leases.",
+	})
+
+	leaseRevoked = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "revoked_total",
+		Help:      "The total number of revoked leases.",
+	})
+
+	leaseRenewed = prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "lease",
+		Name:      "renewed_total",
+		Help:      "The number of renewed leases seen by the leader.",
+	})
+
+	leaseTotalTTLs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "lease",
+			Name:      "ttl_total",
+			Help:      "Bucketed histogram of lease TTLs.",
+			// 1 second -> 3 months
+			Buckets: prometheus.ExponentialBuckets(1, 2, 24),
+		})
+)
+
+func init() {
+	prometheus.MustRegister(leaseGranted)
+	prometheus.MustRegister(leaseRevoked)
+	prometheus.MustRegister(leaseRenewed)
+	prometheus.MustRegister(leaseTotalTTLs)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/backend.go b/vendor/go.etcd.io/etcd/mvcc/backend/backend.go
new file mode 100644
index 0000000..bffd749
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/backend.go
@@ -0,0 +1,570 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"fmt"
+	"hash/crc32"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/coreos/pkg/capnslog"
+	humanize "github.com/dustin/go-humanize"
+	bolt "go.etcd.io/bbolt"
+	"go.uber.org/zap"
+)
+
+var (
+	defaultBatchLimit    = 10000
+	defaultBatchInterval = 100 * time.Millisecond
+
+	defragLimit = 10000
+
+	// initialMmapSize is the initial size of the mmapped region. Setting this larger than
+	// the potential max db size can prevent writer from blocking reader.
+	// This only works for linux.
+	initialMmapSize = uint64(10 * 1024 * 1024 * 1024)
+
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "mvcc/backend")
+
+	// minSnapshotWarningTimeout is the minimum threshold to trigger a long running snapshot warning.
+	minSnapshotWarningTimeout = 30 * time.Second
+)
+
+type Backend interface {
+	// ReadTx returns a read transaction. It is replaced by ConcurrentReadTx in the main data path, see #10523.
+	ReadTx() ReadTx
+	BatchTx() BatchTx
+	// ConcurrentReadTx returns a non-blocking read transaction.
+	ConcurrentReadTx() ReadTx
+
+	Snapshot() Snapshot
+	Hash(ignores map[IgnoreKey]struct{}) (uint32, error)
+	// Size returns the current size of the backend physically allocated.
+	// The backend can hold DB space that is not utilized at the moment,
+	// since it can conduct pre-allocation or spare unused space for recycling.
+	// Use SizeInUse() instead for the actual DB size.
+	Size() int64
+	// SizeInUse returns the current size of the backend logically in use.
+	// Since the backend can manage free space in a non-byte unit such as
+	// number of pages, the returned value can be not exactly accurate in bytes.
+	SizeInUse() int64
+	// OpenReadTxN returns the number of currently open read transactions in the backend.
+	OpenReadTxN() int64
+	Defrag() error
+	ForceCommit()
+	Close() error
+}
+
+type Snapshot interface {
+	// Size gets the size of the snapshot.
+	Size() int64
+	// WriteTo writes the snapshot into the given writer.
+	WriteTo(w io.Writer) (n int64, err error)
+	// Close closes the snapshot.
+	Close() error
+}
+
+type backend struct {
+	// size and commits are used with atomic operations so they must be
+	// 64-bit aligned, otherwise 32-bit tests will crash
+
+	// size is the number of bytes allocated in the backend
+	size int64
+	// sizeInUse is the number of bytes actually used in the backend
+	sizeInUse int64
+	// commits counts number of commits since start
+	commits int64
+	// openReadTxN is the number of currently open read transactions in the backend
+	openReadTxN int64
+
+	mu sync.RWMutex
+	db *bolt.DB
+
+	batchInterval time.Duration
+	batchLimit    int
+	batchTx       *batchTxBuffered
+
+	readTx *readTx
+
+	stopc chan struct{}
+	donec chan struct{}
+
+	lg *zap.Logger
+}
+
+type BackendConfig struct {
+	// Path is the file path to the backend file.
+	Path string
+	// BatchInterval is the maximum time before flushing the BatchTx.
+	BatchInterval time.Duration
+	// BatchLimit is the maximum puts before flushing the BatchTx.
+	BatchLimit int
+	// BackendFreelistType is the backend boltdb's freelist type.
+	BackendFreelistType bolt.FreelistType
+	// MmapSize is the number of bytes to mmap for the backend.
+	MmapSize uint64
+	// Logger logs backend-side operations.
+	Logger *zap.Logger
+}
+
+func DefaultBackendConfig() BackendConfig {
+	return BackendConfig{
+		BatchInterval: defaultBatchInterval,
+		BatchLimit:    defaultBatchLimit,
+		MmapSize:      initialMmapSize,
+	}
+}
+
+func New(bcfg BackendConfig) Backend {
+	return newBackend(bcfg)
+}
+
+func NewDefaultBackend(path string) Backend {
+	bcfg := DefaultBackendConfig()
+	bcfg.Path = path
+	return newBackend(bcfg)
+}
+
+func newBackend(bcfg BackendConfig) *backend {
+	bopts := &bolt.Options{}
+	if boltOpenOptions != nil {
+		*bopts = *boltOpenOptions
+	}
+	bopts.InitialMmapSize = bcfg.mmapSize()
+	bopts.FreelistType = bcfg.BackendFreelistType
+
+	db, err := bolt.Open(bcfg.Path, 0600, bopts)
+	if err != nil {
+		if bcfg.Logger != nil {
+			bcfg.Logger.Panic("failed to open database", zap.String("path", bcfg.Path), zap.Error(err))
+		} else {
+			plog.Panicf("cannot open database at %s (%v)", bcfg.Path, err)
+		}
+	}
+
+	// In future, may want to make buffering optional for low-concurrency systems
+	// or dynamically swap between buffered/non-buffered depending on workload.
+	b := &backend{
+		db: db,
+
+		batchInterval: bcfg.BatchInterval,
+		batchLimit:    bcfg.BatchLimit,
+
+		readTx: &readTx{
+			buf: txReadBuffer{
+				txBuffer: txBuffer{make(map[string]*bucketBuffer)},
+			},
+			buckets: make(map[string]*bolt.Bucket),
+			txWg:    new(sync.WaitGroup),
+		},
+
+		stopc: make(chan struct{}),
+		donec: make(chan struct{}),
+
+		lg: bcfg.Logger,
+	}
+	b.batchTx = newBatchTxBuffered(b)
+	go b.run()
+	return b
+}
+
+// BatchTx returns the current batch tx in coalescer. The tx can be used for read and
+// write operations. The write result can be retrieved within the same tx immediately.
+// The write result is isolated with other txs until the current one get committed.
+func (b *backend) BatchTx() BatchTx {
+	return b.batchTx
+}
+
+func (b *backend) ReadTx() ReadTx { return b.readTx }
+
+// ConcurrentReadTx creates and returns a new ReadTx, which:
+// A) creates and keeps a copy of backend.readTx.txReadBuffer,
+// B) references the boltdb read Tx (and its bucket cache) of current batch interval.
+func (b *backend) ConcurrentReadTx() ReadTx {
+	b.readTx.RLock()
+	defer b.readTx.RUnlock()
+	// prevent boltdb read Tx from been rolled back until store read Tx is done. Needs to be called when holding readTx.RLock().
+	b.readTx.txWg.Add(1)
+	// TODO: might want to copy the read buffer lazily - create copy when A) end of a write transaction B) end of a batch interval.
+	return &concurrentReadTx{
+		buf:     b.readTx.buf.unsafeCopy(),
+		tx:      b.readTx.tx,
+		txMu:    &b.readTx.txMu,
+		buckets: b.readTx.buckets,
+		txWg:    b.readTx.txWg,
+	}
+}
+
+// ForceCommit forces the current batching tx to commit.
+func (b *backend) ForceCommit() {
+	b.batchTx.Commit()
+}
+
+func (b *backend) Snapshot() Snapshot {
+	b.batchTx.Commit()
+
+	b.mu.RLock()
+	defer b.mu.RUnlock()
+	tx, err := b.db.Begin(false)
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to begin tx", zap.Error(err))
+		} else {
+			plog.Fatalf("cannot begin tx (%s)", err)
+		}
+	}
+
+	stopc, donec := make(chan struct{}), make(chan struct{})
+	dbBytes := tx.Size()
+	go func() {
+		defer close(donec)
+		// sendRateBytes is based on transferring snapshot data over a 1 gigabit/s connection
+		// assuming a min tcp throughput of 100MB/s.
+		var sendRateBytes int64 = 100 * 1024 * 1014
+		warningTimeout := time.Duration(int64((float64(dbBytes) / float64(sendRateBytes)) * float64(time.Second)))
+		if warningTimeout < minSnapshotWarningTimeout {
+			warningTimeout = minSnapshotWarningTimeout
+		}
+		start := time.Now()
+		ticker := time.NewTicker(warningTimeout)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ticker.C:
+				if b.lg != nil {
+					b.lg.Warn(
+						"snapshotting taking too long to transfer",
+						zap.Duration("taking", time.Since(start)),
+						zap.Int64("bytes", dbBytes),
+						zap.String("size", humanize.Bytes(uint64(dbBytes))),
+					)
+				} else {
+					plog.Warningf("snapshotting is taking more than %v seconds to finish transferring %v MB [started at %v]", time.Since(start).Seconds(), float64(dbBytes)/float64(1024*1014), start)
+				}
+
+			case <-stopc:
+				snapshotTransferSec.Observe(time.Since(start).Seconds())
+				return
+			}
+		}
+	}()
+
+	return &snapshot{tx, stopc, donec}
+}
+
+type IgnoreKey struct {
+	Bucket string
+	Key    string
+}
+
+func (b *backend) Hash(ignores map[IgnoreKey]struct{}) (uint32, error) {
+	h := crc32.New(crc32.MakeTable(crc32.Castagnoli))
+
+	b.mu.RLock()
+	defer b.mu.RUnlock()
+	err := b.db.View(func(tx *bolt.Tx) error {
+		c := tx.Cursor()
+		for next, _ := c.First(); next != nil; next, _ = c.Next() {
+			b := tx.Bucket(next)
+			if b == nil {
+				return fmt.Errorf("cannot get hash of bucket %s", string(next))
+			}
+			h.Write(next)
+			b.ForEach(func(k, v []byte) error {
+				bk := IgnoreKey{Bucket: string(next), Key: string(k)}
+				if _, ok := ignores[bk]; !ok {
+					h.Write(k)
+					h.Write(v)
+				}
+				return nil
+			})
+		}
+		return nil
+	})
+
+	if err != nil {
+		return 0, err
+	}
+
+	return h.Sum32(), nil
+}
+
+func (b *backend) Size() int64 {
+	return atomic.LoadInt64(&b.size)
+}
+
+func (b *backend) SizeInUse() int64 {
+	return atomic.LoadInt64(&b.sizeInUse)
+}
+
+func (b *backend) run() {
+	defer close(b.donec)
+	t := time.NewTimer(b.batchInterval)
+	defer t.Stop()
+	for {
+		select {
+		case <-t.C:
+		case <-b.stopc:
+			b.batchTx.CommitAndStop()
+			return
+		}
+		if b.batchTx.safePending() != 0 {
+			b.batchTx.Commit()
+		}
+		t.Reset(b.batchInterval)
+	}
+}
+
+func (b *backend) Close() error {
+	close(b.stopc)
+	<-b.donec
+	return b.db.Close()
+}
+
+// Commits returns total number of commits since start
+func (b *backend) Commits() int64 {
+	return atomic.LoadInt64(&b.commits)
+}
+
+func (b *backend) Defrag() error {
+	return b.defrag()
+}
+
+func (b *backend) defrag() error {
+	now := time.Now()
+
+	// TODO: make this non-blocking?
+	// lock batchTx to ensure nobody is using previous tx, and then
+	// close previous ongoing tx.
+	b.batchTx.Lock()
+	defer b.batchTx.Unlock()
+
+	// lock database after lock tx to avoid deadlock.
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	// block concurrent read requests while resetting tx
+	b.readTx.Lock()
+	defer b.readTx.Unlock()
+
+	b.batchTx.unsafeCommit(true)
+
+	b.batchTx.tx = nil
+
+	tmpdb, err := bolt.Open(b.db.Path()+".tmp", 0600, boltOpenOptions)
+	if err != nil {
+		return err
+	}
+
+	dbp := b.db.Path()
+	tdbp := tmpdb.Path()
+	size1, sizeInUse1 := b.Size(), b.SizeInUse()
+	if b.lg != nil {
+		b.lg.Info(
+			"defragmenting",
+			zap.String("path", dbp),
+			zap.Int64("current-db-size-bytes", size1),
+			zap.String("current-db-size", humanize.Bytes(uint64(size1))),
+			zap.Int64("current-db-size-in-use-bytes", sizeInUse1),
+			zap.String("current-db-size-in-use", humanize.Bytes(uint64(sizeInUse1))),
+		)
+	}
+
+	err = defragdb(b.db, tmpdb, defragLimit)
+	if err != nil {
+		tmpdb.Close()
+		os.RemoveAll(tmpdb.Path())
+		return err
+	}
+
+	err = b.db.Close()
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to close database", zap.Error(err))
+		} else {
+			plog.Fatalf("cannot close database (%s)", err)
+		}
+	}
+	err = tmpdb.Close()
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to close tmp database", zap.Error(err))
+		} else {
+			plog.Fatalf("cannot close database (%s)", err)
+		}
+	}
+	err = os.Rename(tdbp, dbp)
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to rename tmp database", zap.Error(err))
+		} else {
+			plog.Fatalf("cannot rename database (%s)", err)
+		}
+	}
+
+	b.db, err = bolt.Open(dbp, 0600, boltOpenOptions)
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to open database", zap.String("path", dbp), zap.Error(err))
+		} else {
+			plog.Panicf("cannot open database at %s (%v)", dbp, err)
+		}
+	}
+	b.batchTx.tx = b.unsafeBegin(true)
+
+	b.readTx.reset()
+	b.readTx.tx = b.unsafeBegin(false)
+
+	size := b.readTx.tx.Size()
+	db := b.readTx.tx.DB()
+	atomic.StoreInt64(&b.size, size)
+	atomic.StoreInt64(&b.sizeInUse, size-(int64(db.Stats().FreePageN)*int64(db.Info().PageSize)))
+
+	took := time.Since(now)
+	defragSec.Observe(took.Seconds())
+
+	size2, sizeInUse2 := b.Size(), b.SizeInUse()
+	if b.lg != nil {
+		b.lg.Info(
+			"defragmented",
+			zap.String("path", dbp),
+			zap.Int64("current-db-size-bytes-diff", size2-size1),
+			zap.Int64("current-db-size-bytes", size2),
+			zap.String("current-db-size", humanize.Bytes(uint64(size2))),
+			zap.Int64("current-db-size-in-use-bytes-diff", sizeInUse2-sizeInUse1),
+			zap.Int64("current-db-size-in-use-bytes", sizeInUse2),
+			zap.String("current-db-size-in-use", humanize.Bytes(uint64(sizeInUse2))),
+			zap.Duration("took", took),
+		)
+	}
+	return nil
+}
+
+func defragdb(odb, tmpdb *bolt.DB, limit int) error {
+	// open a tx on tmpdb for writes
+	tmptx, err := tmpdb.Begin(true)
+	if err != nil {
+		return err
+	}
+
+	// open a tx on old db for read
+	tx, err := odb.Begin(false)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	c := tx.Cursor()
+
+	count := 0
+	for next, _ := c.First(); next != nil; next, _ = c.Next() {
+		b := tx.Bucket(next)
+		if b == nil {
+			return fmt.Errorf("backend: cannot defrag bucket %s", string(next))
+		}
+
+		tmpb, berr := tmptx.CreateBucketIfNotExists(next)
+		if berr != nil {
+			return berr
+		}
+		tmpb.FillPercent = 0.9 // for seq write in for each
+
+		b.ForEach(func(k, v []byte) error {
+			count++
+			if count > limit {
+				err = tmptx.Commit()
+				if err != nil {
+					return err
+				}
+				tmptx, err = tmpdb.Begin(true)
+				if err != nil {
+					return err
+				}
+				tmpb = tmptx.Bucket(next)
+				tmpb.FillPercent = 0.9 // for seq write in for each
+
+				count = 0
+			}
+			return tmpb.Put(k, v)
+		})
+	}
+
+	return tmptx.Commit()
+}
+
+func (b *backend) begin(write bool) *bolt.Tx {
+	b.mu.RLock()
+	tx := b.unsafeBegin(write)
+	b.mu.RUnlock()
+
+	size := tx.Size()
+	db := tx.DB()
+	stats := db.Stats()
+	atomic.StoreInt64(&b.size, size)
+	atomic.StoreInt64(&b.sizeInUse, size-(int64(stats.FreePageN)*int64(db.Info().PageSize)))
+	atomic.StoreInt64(&b.openReadTxN, int64(stats.OpenTxN))
+
+	return tx
+}
+
+func (b *backend) unsafeBegin(write bool) *bolt.Tx {
+	tx, err := b.db.Begin(write)
+	if err != nil {
+		if b.lg != nil {
+			b.lg.Fatal("failed to begin tx", zap.Error(err))
+		} else {
+			plog.Fatalf("cannot begin tx (%s)", err)
+		}
+	}
+	return tx
+}
+
+func (b *backend) OpenReadTxN() int64 {
+	return atomic.LoadInt64(&b.openReadTxN)
+}
+
+// NewTmpBackend creates a backend implementation for testing.
+func NewTmpBackend(batchInterval time.Duration, batchLimit int) (*backend, string) {
+	dir, err := ioutil.TempDir(os.TempDir(), "etcd_backend_test")
+	if err != nil {
+		panic(err)
+	}
+	tmpPath := filepath.Join(dir, "database")
+	bcfg := DefaultBackendConfig()
+	bcfg.Path, bcfg.BatchInterval, bcfg.BatchLimit = tmpPath, batchInterval, batchLimit
+	return newBackend(bcfg), tmpPath
+}
+
+func NewDefaultTmpBackend() (*backend, string) {
+	return NewTmpBackend(defaultBatchInterval, defaultBatchLimit)
+}
+
+type snapshot struct {
+	*bolt.Tx
+	stopc chan struct{}
+	donec chan struct{}
+}
+
+func (s *snapshot) Close() error {
+	close(s.stopc)
+	<-s.donec
+	return s.Tx.Rollback()
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/batch_tx.go b/vendor/go.etcd.io/etcd/mvcc/backend/batch_tx.go
new file mode 100644
index 0000000..d5c8a88
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/batch_tx.go
@@ -0,0 +1,339 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"bytes"
+	"math"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	bolt "go.etcd.io/bbolt"
+	"go.uber.org/zap"
+)
+
+type BatchTx interface {
+	ReadTx
+	UnsafeCreateBucket(name []byte)
+	UnsafePut(bucketName []byte, key []byte, value []byte)
+	UnsafeSeqPut(bucketName []byte, key []byte, value []byte)
+	UnsafeDelete(bucketName []byte, key []byte)
+	// Commit commits a previous tx and begins a new writable one.
+	Commit()
+	// CommitAndStop commits the previous tx and does not create a new one.
+	CommitAndStop()
+}
+
+type batchTx struct {
+	sync.Mutex
+	tx      *bolt.Tx
+	backend *backend
+
+	pending int
+}
+
+func (t *batchTx) Lock() {
+	t.Mutex.Lock()
+}
+
+func (t *batchTx) Unlock() {
+	if t.pending >= t.backend.batchLimit {
+		t.commit(false)
+	}
+	t.Mutex.Unlock()
+}
+
+// BatchTx interface embeds ReadTx interface. But RLock() and RUnlock() do not
+// have appropriate semantics in BatchTx interface. Therefore should not be called.
+// TODO: might want to decouple ReadTx and BatchTx
+
+func (t *batchTx) RLock() {
+	panic("unexpected RLock")
+}
+
+func (t *batchTx) RUnlock() {
+	panic("unexpected RUnlock")
+}
+
+func (t *batchTx) UnsafeCreateBucket(name []byte) {
+	_, err := t.tx.CreateBucket(name)
+	if err != nil && err != bolt.ErrBucketExists {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to create a bucket",
+				zap.String("bucket-name", string(name)),
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot create bucket %s (%v)", name, err)
+		}
+	}
+	t.pending++
+}
+
+// UnsafePut must be called holding the lock on the tx.
+func (t *batchTx) UnsafePut(bucketName []byte, key []byte, value []byte) {
+	t.unsafePut(bucketName, key, value, false)
+}
+
+// UnsafeSeqPut must be called holding the lock on the tx.
+func (t *batchTx) UnsafeSeqPut(bucketName []byte, key []byte, value []byte) {
+	t.unsafePut(bucketName, key, value, true)
+}
+
+func (t *batchTx) unsafePut(bucketName []byte, key []byte, value []byte, seq bool) {
+	bucket := t.tx.Bucket(bucketName)
+	if bucket == nil {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to find a bucket",
+				zap.String("bucket-name", string(bucketName)),
+			)
+		} else {
+			plog.Fatalf("bucket %s does not exist", bucketName)
+		}
+	}
+	if seq {
+		// it is useful to increase fill percent when the workloads are mostly append-only.
+		// this can delay the page split and reduce space usage.
+		bucket.FillPercent = 0.9
+	}
+	if err := bucket.Put(key, value); err != nil {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to write to a bucket",
+				zap.String("bucket-name", string(bucketName)),
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot put key into bucket (%v)", err)
+		}
+	}
+	t.pending++
+}
+
+// UnsafeRange must be called holding the lock on the tx.
+func (t *batchTx) UnsafeRange(bucketName, key, endKey []byte, limit int64) ([][]byte, [][]byte) {
+	bucket := t.tx.Bucket(bucketName)
+	if bucket == nil {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to find a bucket",
+				zap.String("bucket-name", string(bucketName)),
+			)
+		} else {
+			plog.Fatalf("bucket %s does not exist", bucketName)
+		}
+	}
+	return unsafeRange(bucket.Cursor(), key, endKey, limit)
+}
+
+func unsafeRange(c *bolt.Cursor, key, endKey []byte, limit int64) (keys [][]byte, vs [][]byte) {
+	if limit <= 0 {
+		limit = math.MaxInt64
+	}
+	var isMatch func(b []byte) bool
+	if len(endKey) > 0 {
+		isMatch = func(b []byte) bool { return bytes.Compare(b, endKey) < 0 }
+	} else {
+		isMatch = func(b []byte) bool { return bytes.Equal(b, key) }
+		limit = 1
+	}
+
+	for ck, cv := c.Seek(key); ck != nil && isMatch(ck); ck, cv = c.Next() {
+		vs = append(vs, cv)
+		keys = append(keys, ck)
+		if limit == int64(len(keys)) {
+			break
+		}
+	}
+	return keys, vs
+}
+
+// UnsafeDelete must be called holding the lock on the tx.
+func (t *batchTx) UnsafeDelete(bucketName []byte, key []byte) {
+	bucket := t.tx.Bucket(bucketName)
+	if bucket == nil {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to find a bucket",
+				zap.String("bucket-name", string(bucketName)),
+			)
+		} else {
+			plog.Fatalf("bucket %s does not exist", bucketName)
+		}
+	}
+	err := bucket.Delete(key)
+	if err != nil {
+		if t.backend.lg != nil {
+			t.backend.lg.Fatal(
+				"failed to delete a key",
+				zap.String("bucket-name", string(bucketName)),
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot delete key from bucket (%v)", err)
+		}
+	}
+	t.pending++
+}
+
+// UnsafeForEach must be called holding the lock on the tx.
+func (t *batchTx) UnsafeForEach(bucketName []byte, visitor func(k, v []byte) error) error {
+	return unsafeForEach(t.tx, bucketName, visitor)
+}
+
+func unsafeForEach(tx *bolt.Tx, bucket []byte, visitor func(k, v []byte) error) error {
+	if b := tx.Bucket(bucket); b != nil {
+		return b.ForEach(visitor)
+	}
+	return nil
+}
+
+// Commit commits a previous tx and begins a new writable one.
+func (t *batchTx) Commit() {
+	t.Lock()
+	t.commit(false)
+	t.Unlock()
+}
+
+// CommitAndStop commits the previous tx and does not create a new one.
+func (t *batchTx) CommitAndStop() {
+	t.Lock()
+	t.commit(true)
+	t.Unlock()
+}
+
+func (t *batchTx) safePending() int {
+	t.Mutex.Lock()
+	defer t.Mutex.Unlock()
+	return t.pending
+}
+
+func (t *batchTx) commit(stop bool) {
+	// commit the last tx
+	if t.tx != nil {
+		if t.pending == 0 && !stop {
+			return
+		}
+
+		start := time.Now()
+
+		// gofail: var beforeCommit struct{}
+		err := t.tx.Commit()
+		// gofail: var afterCommit struct{}
+
+		rebalanceSec.Observe(t.tx.Stats().RebalanceTime.Seconds())
+		spillSec.Observe(t.tx.Stats().SpillTime.Seconds())
+		writeSec.Observe(t.tx.Stats().WriteTime.Seconds())
+		commitSec.Observe(time.Since(start).Seconds())
+		atomic.AddInt64(&t.backend.commits, 1)
+
+		t.pending = 0
+		if err != nil {
+			if t.backend.lg != nil {
+				t.backend.lg.Fatal("failed to commit tx", zap.Error(err))
+			} else {
+				plog.Fatalf("cannot commit tx (%s)", err)
+			}
+		}
+	}
+	if !stop {
+		t.tx = t.backend.begin(true)
+	}
+}
+
+type batchTxBuffered struct {
+	batchTx
+	buf txWriteBuffer
+}
+
+func newBatchTxBuffered(backend *backend) *batchTxBuffered {
+	tx := &batchTxBuffered{
+		batchTx: batchTx{backend: backend},
+		buf: txWriteBuffer{
+			txBuffer: txBuffer{make(map[string]*bucketBuffer)},
+			seq:      true,
+		},
+	}
+	tx.Commit()
+	return tx
+}
+
+func (t *batchTxBuffered) Unlock() {
+	if t.pending != 0 {
+		t.backend.readTx.Lock() // blocks txReadBuffer for writing.
+		t.buf.writeback(&t.backend.readTx.buf)
+		t.backend.readTx.Unlock()
+		if t.pending >= t.backend.batchLimit {
+			t.commit(false)
+		}
+	}
+	t.batchTx.Unlock()
+}
+
+func (t *batchTxBuffered) Commit() {
+	t.Lock()
+	t.commit(false)
+	t.Unlock()
+}
+
+func (t *batchTxBuffered) CommitAndStop() {
+	t.Lock()
+	t.commit(true)
+	t.Unlock()
+}
+
+func (t *batchTxBuffered) commit(stop bool) {
+	// all read txs must be closed to acquire boltdb commit rwlock
+	t.backend.readTx.Lock()
+	t.unsafeCommit(stop)
+	t.backend.readTx.Unlock()
+}
+
+func (t *batchTxBuffered) unsafeCommit(stop bool) {
+	if t.backend.readTx.tx != nil {
+		// wait all store read transactions using the current boltdb tx to finish,
+		// then close the boltdb tx
+		go func(tx *bolt.Tx, wg *sync.WaitGroup) {
+			wg.Wait()
+			if err := tx.Rollback(); err != nil {
+				if t.backend.lg != nil {
+					t.backend.lg.Fatal("failed to rollback tx", zap.Error(err))
+				} else {
+					plog.Fatalf("cannot rollback tx (%s)", err)
+				}
+			}
+		}(t.backend.readTx.tx, t.backend.readTx.txWg)
+		t.backend.readTx.reset()
+	}
+
+	t.batchTx.commit(stop)
+
+	if !stop {
+		t.backend.readTx.tx = t.backend.begin(false)
+	}
+}
+
+func (t *batchTxBuffered) UnsafePut(bucketName []byte, key []byte, value []byte) {
+	t.batchTx.UnsafePut(bucketName, key, value)
+	t.buf.put(bucketName, key, value)
+}
+
+func (t *batchTxBuffered) UnsafeSeqPut(bucketName []byte, key []byte, value []byte) {
+	t.batchTx.UnsafeSeqPut(bucketName, key, value)
+	t.buf.putSeq(bucketName, key, value)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/config_default.go b/vendor/go.etcd.io/etcd/mvcc/backend/config_default.go
new file mode 100644
index 0000000..f15f030
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/config_default.go
@@ -0,0 +1,23 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux,!windows
+
+package backend
+
+import bolt "go.etcd.io/bbolt"
+
+var boltOpenOptions *bolt.Options
+
+func (bcfg *BackendConfig) mmapSize() int { return int(bcfg.MmapSize) }
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go b/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go
new file mode 100644
index 0000000..f712671
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go
@@ -0,0 +1,34 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"syscall"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+// syscall.MAP_POPULATE on linux 2.6.23+ does sequential read-ahead
+// which can speed up entire-database read with boltdb. We want to
+// enable MAP_POPULATE for faster key-value store recovery in storage
+// package. If your kernel version is lower than 2.6.23
+// (https://github.com/torvalds/linux/releases/tag/v2.6.23), mmap might
+// silently ignore this flag. Please update your kernel to prevent this.
+var boltOpenOptions = &bolt.Options{
+	MmapFlags:      syscall.MAP_POPULATE,
+	NoFreelistSync: true,
+}
+
+func (bcfg *BackendConfig) mmapSize() int { return int(bcfg.MmapSize) }
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/config_windows.go b/vendor/go.etcd.io/etcd/mvcc/backend/config_windows.go
new file mode 100644
index 0000000..c650059
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/config_windows.go
@@ -0,0 +1,26 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build windows
+
+package backend
+
+import bolt "go.etcd.io/bbolt"
+
+var boltOpenOptions *bolt.Options = nil
+
+// setting mmap size != 0 on windows will allocate the entire
+// mmap size for the file, instead of growing it. So, force 0.
+
+func (bcfg *BackendConfig) mmapSize() int { return 0 }
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/doc.go b/vendor/go.etcd.io/etcd/mvcc/backend/doc.go
new file mode 100644
index 0000000..9cc42fa
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package backend defines a standard interface for etcd's backend MVCC storage.
+package backend
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/metrics.go b/vendor/go.etcd.io/etcd/mvcc/backend/metrics.go
new file mode 100644
index 0000000..d9641af
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/metrics.go
@@ -0,0 +1,95 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	commitSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "disk",
+		Name:      "backend_commit_duration_seconds",
+		Help:      "The latency distributions of commit called by backend.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	rebalanceSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "disk",
+		Name:      "backend_commit_rebalance_duration_seconds",
+		Help:      "The latency distributions of commit.rebalance called by bboltdb backend.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	spillSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "disk",
+		Name:      "backend_commit_spill_duration_seconds",
+		Help:      "The latency distributions of commit.spill called by bboltdb backend.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	writeSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "disk",
+		Name:      "backend_commit_write_duration_seconds",
+		Help:      "The latency distributions of commit.write called by bboltdb backend.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+
+	defragSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "disk",
+		Name:      "backend_defrag_duration_seconds",
+		Help:      "The latency distribution of backend defragmentation.",
+
+		// 100 MB usually takes 1 sec, so start with 10 MB of 100 ms
+		// lowest bucket start of upper bound 0.1 sec (100 ms) with factor 2
+		// highest bucket start of 0.1 sec * 2^12 == 409.6 sec
+		Buckets: prometheus.ExponentialBuckets(.1, 2, 13),
+	})
+
+	snapshotTransferSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "disk",
+		Name:      "backend_snapshot_duration_seconds",
+		Help:      "The latency distribution of backend snapshots.",
+
+		// lowest bucket start of upper bound 0.01 sec (10 ms) with factor 2
+		// highest bucket start of 0.01 sec * 2^16 == 655.36 sec
+		Buckets: prometheus.ExponentialBuckets(.01, 2, 17),
+	})
+)
+
+func init() {
+	prometheus.MustRegister(commitSec)
+	prometheus.MustRegister(rebalanceSec)
+	prometheus.MustRegister(spillSec)
+	prometheus.MustRegister(writeSec)
+	prometheus.MustRegister(defragSec)
+	prometheus.MustRegister(snapshotTransferSec)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/read_tx.go b/vendor/go.etcd.io/etcd/mvcc/backend/read_tx.go
new file mode 100644
index 0000000..91fe72e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/read_tx.go
@@ -0,0 +1,210 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"bytes"
+	"math"
+	"sync"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+// safeRangeBucket is a hack to avoid inadvertently reading duplicate keys;
+// overwrites on a bucket should only fetch with limit=1, but safeRangeBucket
+// is known to never overwrite any key so range is safe.
+var safeRangeBucket = []byte("key")
+
+type ReadTx interface {
+	Lock()
+	Unlock()
+	RLock()
+	RUnlock()
+
+	UnsafeRange(bucketName []byte, key, endKey []byte, limit int64) (keys [][]byte, vals [][]byte)
+	UnsafeForEach(bucketName []byte, visitor func(k, v []byte) error) error
+}
+
+type readTx struct {
+	// mu protects accesses to the txReadBuffer
+	mu  sync.RWMutex
+	buf txReadBuffer
+
+	// TODO: group and encapsulate {txMu, tx, buckets, txWg}, as they share the same lifecycle.
+	// txMu protects accesses to buckets and tx on Range requests.
+	txMu    sync.RWMutex
+	tx      *bolt.Tx
+	buckets map[string]*bolt.Bucket
+	// txWg protects tx from being rolled back at the end of a batch interval until all reads using this tx are done.
+	txWg *sync.WaitGroup
+}
+
+func (rt *readTx) Lock()    { rt.mu.Lock() }
+func (rt *readTx) Unlock()  { rt.mu.Unlock() }
+func (rt *readTx) RLock()   { rt.mu.RLock() }
+func (rt *readTx) RUnlock() { rt.mu.RUnlock() }
+
+func (rt *readTx) UnsafeRange(bucketName, key, endKey []byte, limit int64) ([][]byte, [][]byte) {
+	if endKey == nil {
+		// forbid duplicates for single keys
+		limit = 1
+	}
+	if limit <= 0 {
+		limit = math.MaxInt64
+	}
+	if limit > 1 && !bytes.Equal(bucketName, safeRangeBucket) {
+		panic("do not use unsafeRange on non-keys bucket")
+	}
+	keys, vals := rt.buf.Range(bucketName, key, endKey, limit)
+	if int64(len(keys)) == limit {
+		return keys, vals
+	}
+
+	// find/cache bucket
+	bn := string(bucketName)
+	rt.txMu.RLock()
+	bucket, ok := rt.buckets[bn]
+	rt.txMu.RUnlock()
+	if !ok {
+		rt.txMu.Lock()
+		bucket = rt.tx.Bucket(bucketName)
+		rt.buckets[bn] = bucket
+		rt.txMu.Unlock()
+	}
+
+	// ignore missing bucket since may have been created in this batch
+	if bucket == nil {
+		return keys, vals
+	}
+	rt.txMu.Lock()
+	c := bucket.Cursor()
+	rt.txMu.Unlock()
+
+	k2, v2 := unsafeRange(c, key, endKey, limit-int64(len(keys)))
+	return append(k2, keys...), append(v2, vals...)
+}
+
+func (rt *readTx) UnsafeForEach(bucketName []byte, visitor func(k, v []byte) error) error {
+	dups := make(map[string]struct{})
+	getDups := func(k, v []byte) error {
+		dups[string(k)] = struct{}{}
+		return nil
+	}
+	visitNoDup := func(k, v []byte) error {
+		if _, ok := dups[string(k)]; ok {
+			return nil
+		}
+		return visitor(k, v)
+	}
+	if err := rt.buf.ForEach(bucketName, getDups); err != nil {
+		return err
+	}
+	rt.txMu.Lock()
+	err := unsafeForEach(rt.tx, bucketName, visitNoDup)
+	rt.txMu.Unlock()
+	if err != nil {
+		return err
+	}
+	return rt.buf.ForEach(bucketName, visitor)
+}
+
+func (rt *readTx) reset() {
+	rt.buf.reset()
+	rt.buckets = make(map[string]*bolt.Bucket)
+	rt.tx = nil
+	rt.txWg = new(sync.WaitGroup)
+}
+
+// TODO: create a base type for readTx and concurrentReadTx to avoid duplicated function implementation?
+type concurrentReadTx struct {
+	buf     txReadBuffer
+	txMu    *sync.RWMutex
+	tx      *bolt.Tx
+	buckets map[string]*bolt.Bucket
+	txWg    *sync.WaitGroup
+}
+
+func (rt *concurrentReadTx) Lock()   {}
+func (rt *concurrentReadTx) Unlock() {}
+
+// RLock is no-op. concurrentReadTx does not need to be locked after it is created.
+func (rt *concurrentReadTx) RLock() {}
+
+// RUnlock signals the end of concurrentReadTx.
+func (rt *concurrentReadTx) RUnlock() { rt.txWg.Done() }
+
+func (rt *concurrentReadTx) UnsafeForEach(bucketName []byte, visitor func(k, v []byte) error) error {
+	dups := make(map[string]struct{})
+	getDups := func(k, v []byte) error {
+		dups[string(k)] = struct{}{}
+		return nil
+	}
+	visitNoDup := func(k, v []byte) error {
+		if _, ok := dups[string(k)]; ok {
+			return nil
+		}
+		return visitor(k, v)
+	}
+	if err := rt.buf.ForEach(bucketName, getDups); err != nil {
+		return err
+	}
+	rt.txMu.Lock()
+	err := unsafeForEach(rt.tx, bucketName, visitNoDup)
+	rt.txMu.Unlock()
+	if err != nil {
+		return err
+	}
+	return rt.buf.ForEach(bucketName, visitor)
+}
+
+func (rt *concurrentReadTx) UnsafeRange(bucketName, key, endKey []byte, limit int64) ([][]byte, [][]byte) {
+	if endKey == nil {
+		// forbid duplicates for single keys
+		limit = 1
+	}
+	if limit <= 0 {
+		limit = math.MaxInt64
+	}
+	if limit > 1 && !bytes.Equal(bucketName, safeRangeBucket) {
+		panic("do not use unsafeRange on non-keys bucket")
+	}
+	keys, vals := rt.buf.Range(bucketName, key, endKey, limit)
+	if int64(len(keys)) == limit {
+		return keys, vals
+	}
+
+	// find/cache bucket
+	bn := string(bucketName)
+	rt.txMu.RLock()
+	bucket, ok := rt.buckets[bn]
+	rt.txMu.RUnlock()
+	if !ok {
+		rt.txMu.Lock()
+		bucket = rt.tx.Bucket(bucketName)
+		rt.buckets[bn] = bucket
+		rt.txMu.Unlock()
+	}
+
+	// ignore missing bucket since may have been created in this batch
+	if bucket == nil {
+		return keys, vals
+	}
+	rt.txMu.Lock()
+	c := bucket.Cursor()
+	rt.txMu.Unlock()
+
+	k2, v2 := unsafeRange(c, key, endKey, limit-int64(len(keys)))
+	return append(k2, keys...), append(v2, vals...)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/tx_buffer.go b/vendor/go.etcd.io/etcd/mvcc/backend/tx_buffer.go
new file mode 100644
index 0000000..d734638
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/tx_buffer.go
@@ -0,0 +1,203 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"bytes"
+	"sort"
+)
+
+// txBuffer handles functionality shared between txWriteBuffer and txReadBuffer.
+type txBuffer struct {
+	buckets map[string]*bucketBuffer
+}
+
+func (txb *txBuffer) reset() {
+	for k, v := range txb.buckets {
+		if v.used == 0 {
+			// demote
+			delete(txb.buckets, k)
+		}
+		v.used = 0
+	}
+}
+
+// txWriteBuffer buffers writes of pending updates that have not yet committed.
+type txWriteBuffer struct {
+	txBuffer
+	seq bool
+}
+
+func (txw *txWriteBuffer) put(bucket, k, v []byte) {
+	txw.seq = false
+	txw.putSeq(bucket, k, v)
+}
+
+func (txw *txWriteBuffer) putSeq(bucket, k, v []byte) {
+	b, ok := txw.buckets[string(bucket)]
+	if !ok {
+		b = newBucketBuffer()
+		txw.buckets[string(bucket)] = b
+	}
+	b.add(k, v)
+}
+
+func (txw *txWriteBuffer) writeback(txr *txReadBuffer) {
+	for k, wb := range txw.buckets {
+		rb, ok := txr.buckets[k]
+		if !ok {
+			delete(txw.buckets, k)
+			txr.buckets[k] = wb
+			continue
+		}
+		if !txw.seq && wb.used > 1 {
+			// assume no duplicate keys
+			sort.Sort(wb)
+		}
+		rb.merge(wb)
+	}
+	txw.reset()
+}
+
+// txReadBuffer accesses buffered updates.
+type txReadBuffer struct{ txBuffer }
+
+func (txr *txReadBuffer) Range(bucketName, key, endKey []byte, limit int64) ([][]byte, [][]byte) {
+	if b := txr.buckets[string(bucketName)]; b != nil {
+		return b.Range(key, endKey, limit)
+	}
+	return nil, nil
+}
+
+func (txr *txReadBuffer) ForEach(bucketName []byte, visitor func(k, v []byte) error) error {
+	if b := txr.buckets[string(bucketName)]; b != nil {
+		return b.ForEach(visitor)
+	}
+	return nil
+}
+
+// unsafeCopy returns a copy of txReadBuffer, caller should acquire backend.readTx.RLock()
+func (txr *txReadBuffer) unsafeCopy() txReadBuffer {
+	txrCopy := txReadBuffer{
+		txBuffer: txBuffer{
+			buckets: make(map[string]*bucketBuffer, len(txr.txBuffer.buckets)),
+		},
+	}
+	for bucketName, bucket := range txr.txBuffer.buckets {
+		txrCopy.txBuffer.buckets[bucketName] = bucket.Copy()
+	}
+	return txrCopy
+}
+
+type kv struct {
+	key []byte
+	val []byte
+}
+
+// bucketBuffer buffers key-value pairs that are pending commit.
+type bucketBuffer struct {
+	buf []kv
+	// used tracks number of elements in use so buf can be reused without reallocation.
+	used int
+}
+
+func newBucketBuffer() *bucketBuffer {
+	return &bucketBuffer{buf: make([]kv, 512), used: 0}
+}
+
+func (bb *bucketBuffer) Range(key, endKey []byte, limit int64) (keys [][]byte, vals [][]byte) {
+	f := func(i int) bool { return bytes.Compare(bb.buf[i].key, key) >= 0 }
+	idx := sort.Search(bb.used, f)
+	if idx < 0 {
+		return nil, nil
+	}
+	if len(endKey) == 0 {
+		if bytes.Equal(key, bb.buf[idx].key) {
+			keys = append(keys, bb.buf[idx].key)
+			vals = append(vals, bb.buf[idx].val)
+		}
+		return keys, vals
+	}
+	if bytes.Compare(endKey, bb.buf[idx].key) <= 0 {
+		return nil, nil
+	}
+	for i := idx; i < bb.used && int64(len(keys)) < limit; i++ {
+		if bytes.Compare(endKey, bb.buf[i].key) <= 0 {
+			break
+		}
+		keys = append(keys, bb.buf[i].key)
+		vals = append(vals, bb.buf[i].val)
+	}
+	return keys, vals
+}
+
+func (bb *bucketBuffer) ForEach(visitor func(k, v []byte) error) error {
+	for i := 0; i < bb.used; i++ {
+		if err := visitor(bb.buf[i].key, bb.buf[i].val); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (bb *bucketBuffer) add(k, v []byte) {
+	bb.buf[bb.used].key, bb.buf[bb.used].val = k, v
+	bb.used++
+	if bb.used == len(bb.buf) {
+		buf := make([]kv, (3*len(bb.buf))/2)
+		copy(buf, bb.buf)
+		bb.buf = buf
+	}
+}
+
+// merge merges data from bb into bbsrc.
+func (bb *bucketBuffer) merge(bbsrc *bucketBuffer) {
+	for i := 0; i < bbsrc.used; i++ {
+		bb.add(bbsrc.buf[i].key, bbsrc.buf[i].val)
+	}
+	if bb.used == bbsrc.used {
+		return
+	}
+	if bytes.Compare(bb.buf[(bb.used-bbsrc.used)-1].key, bbsrc.buf[0].key) < 0 {
+		return
+	}
+
+	sort.Stable(bb)
+
+	// remove duplicates, using only newest update
+	widx := 0
+	for ridx := 1; ridx < bb.used; ridx++ {
+		if !bytes.Equal(bb.buf[ridx].key, bb.buf[widx].key) {
+			widx++
+		}
+		bb.buf[widx] = bb.buf[ridx]
+	}
+	bb.used = widx + 1
+}
+
+func (bb *bucketBuffer) Len() int { return bb.used }
+func (bb *bucketBuffer) Less(i, j int) bool {
+	return bytes.Compare(bb.buf[i].key, bb.buf[j].key) < 0
+}
+func (bb *bucketBuffer) Swap(i, j int) { bb.buf[i], bb.buf[j] = bb.buf[j], bb.buf[i] }
+
+func (bb *bucketBuffer) Copy() *bucketBuffer {
+	bbCopy := bucketBuffer{
+		buf:  make([]kv, len(bb.buf)),
+		used: bb.used,
+	}
+	copy(bbCopy.buf, bb.buf)
+	return &bbCopy
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/doc.go b/vendor/go.etcd.io/etcd/mvcc/doc.go
new file mode 100644
index 0000000..ad5be03
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package mvcc defines etcd's stable MVCC storage.
+package mvcc
diff --git a/vendor/go.etcd.io/etcd/mvcc/index.go b/vendor/go.etcd.io/etcd/mvcc/index.go
new file mode 100644
index 0000000..f8cc6df
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/index.go
@@ -0,0 +1,258 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"sort"
+	"sync"
+
+	"github.com/google/btree"
+	"go.uber.org/zap"
+)
+
+type index interface {
+	Get(key []byte, atRev int64) (rev, created revision, ver int64, err error)
+	Range(key, end []byte, atRev int64) ([][]byte, []revision)
+	Revisions(key, end []byte, atRev int64) []revision
+	Put(key []byte, rev revision)
+	Tombstone(key []byte, rev revision) error
+	RangeSince(key, end []byte, rev int64) []revision
+	Compact(rev int64) map[revision]struct{}
+	Keep(rev int64) map[revision]struct{}
+	Equal(b index) bool
+
+	Insert(ki *keyIndex)
+	KeyIndex(ki *keyIndex) *keyIndex
+}
+
+type treeIndex struct {
+	sync.RWMutex
+	tree *btree.BTree
+	lg   *zap.Logger
+}
+
+func newTreeIndex(lg *zap.Logger) index {
+	return &treeIndex{
+		tree: btree.New(32),
+		lg:   lg,
+	}
+}
+
+func (ti *treeIndex) Put(key []byte, rev revision) {
+	keyi := &keyIndex{key: key}
+
+	ti.Lock()
+	defer ti.Unlock()
+	item := ti.tree.Get(keyi)
+	if item == nil {
+		keyi.put(ti.lg, rev.main, rev.sub)
+		ti.tree.ReplaceOrInsert(keyi)
+		return
+	}
+	okeyi := item.(*keyIndex)
+	okeyi.put(ti.lg, rev.main, rev.sub)
+}
+
+func (ti *treeIndex) Get(key []byte, atRev int64) (modified, created revision, ver int64, err error) {
+	keyi := &keyIndex{key: key}
+	ti.RLock()
+	defer ti.RUnlock()
+	if keyi = ti.keyIndex(keyi); keyi == nil {
+		return revision{}, revision{}, 0, ErrRevisionNotFound
+	}
+	return keyi.get(ti.lg, atRev)
+}
+
+func (ti *treeIndex) KeyIndex(keyi *keyIndex) *keyIndex {
+	ti.RLock()
+	defer ti.RUnlock()
+	return ti.keyIndex(keyi)
+}
+
+func (ti *treeIndex) keyIndex(keyi *keyIndex) *keyIndex {
+	if item := ti.tree.Get(keyi); item != nil {
+		return item.(*keyIndex)
+	}
+	return nil
+}
+
+func (ti *treeIndex) visit(key, end []byte, f func(ki *keyIndex)) {
+	keyi, endi := &keyIndex{key: key}, &keyIndex{key: end}
+
+	ti.RLock()
+	defer ti.RUnlock()
+
+	ti.tree.AscendGreaterOrEqual(keyi, func(item btree.Item) bool {
+		if len(endi.key) > 0 && !item.Less(endi) {
+			return false
+		}
+		f(item.(*keyIndex))
+		return true
+	})
+}
+
+func (ti *treeIndex) Revisions(key, end []byte, atRev int64) (revs []revision) {
+	if end == nil {
+		rev, _, _, err := ti.Get(key, atRev)
+		if err != nil {
+			return nil
+		}
+		return []revision{rev}
+	}
+	ti.visit(key, end, func(ki *keyIndex) {
+		if rev, _, _, err := ki.get(ti.lg, atRev); err == nil {
+			revs = append(revs, rev)
+		}
+	})
+	return revs
+}
+
+func (ti *treeIndex) Range(key, end []byte, atRev int64) (keys [][]byte, revs []revision) {
+	if end == nil {
+		rev, _, _, err := ti.Get(key, atRev)
+		if err != nil {
+			return nil, nil
+		}
+		return [][]byte{key}, []revision{rev}
+	}
+	ti.visit(key, end, func(ki *keyIndex) {
+		if rev, _, _, err := ki.get(ti.lg, atRev); err == nil {
+			revs = append(revs, rev)
+			keys = append(keys, ki.key)
+		}
+	})
+	return keys, revs
+}
+
+func (ti *treeIndex) Tombstone(key []byte, rev revision) error {
+	keyi := &keyIndex{key: key}
+
+	ti.Lock()
+	defer ti.Unlock()
+	item := ti.tree.Get(keyi)
+	if item == nil {
+		return ErrRevisionNotFound
+	}
+
+	ki := item.(*keyIndex)
+	return ki.tombstone(ti.lg, rev.main, rev.sub)
+}
+
+// RangeSince returns all revisions from key(including) to end(excluding)
+// at or after the given rev. The returned slice is sorted in the order
+// of revision.
+func (ti *treeIndex) RangeSince(key, end []byte, rev int64) []revision {
+	keyi := &keyIndex{key: key}
+
+	ti.RLock()
+	defer ti.RUnlock()
+
+	if end == nil {
+		item := ti.tree.Get(keyi)
+		if item == nil {
+			return nil
+		}
+		keyi = item.(*keyIndex)
+		return keyi.since(ti.lg, rev)
+	}
+
+	endi := &keyIndex{key: end}
+	var revs []revision
+	ti.tree.AscendGreaterOrEqual(keyi, func(item btree.Item) bool {
+		if len(endi.key) > 0 && !item.Less(endi) {
+			return false
+		}
+		curKeyi := item.(*keyIndex)
+		revs = append(revs, curKeyi.since(ti.lg, rev)...)
+		return true
+	})
+	sort.Sort(revisions(revs))
+
+	return revs
+}
+
+func (ti *treeIndex) Compact(rev int64) map[revision]struct{} {
+	available := make(map[revision]struct{})
+	if ti.lg != nil {
+		ti.lg.Info("compact tree index", zap.Int64("revision", rev))
+	} else {
+		plog.Printf("store.index: compact %d", rev)
+	}
+	ti.Lock()
+	clone := ti.tree.Clone()
+	ti.Unlock()
+
+	clone.Ascend(func(item btree.Item) bool {
+		keyi := item.(*keyIndex)
+		//Lock is needed here to prevent modification to the keyIndex while
+		//compaction is going on or revision added to empty before deletion
+		ti.Lock()
+		keyi.compact(ti.lg, rev, available)
+		if keyi.isEmpty() {
+			item := ti.tree.Delete(keyi)
+			if item == nil {
+				if ti.lg != nil {
+					ti.lg.Panic("failed to delete during compaction")
+				} else {
+					plog.Panic("store.index: unexpected delete failure during compaction")
+				}
+			}
+		}
+		ti.Unlock()
+		return true
+	})
+	return available
+}
+
+// Keep finds all revisions to be kept for a Compaction at the given rev.
+func (ti *treeIndex) Keep(rev int64) map[revision]struct{} {
+	available := make(map[revision]struct{})
+	ti.RLock()
+	defer ti.RUnlock()
+	ti.tree.Ascend(func(i btree.Item) bool {
+		keyi := i.(*keyIndex)
+		keyi.keep(rev, available)
+		return true
+	})
+	return available
+}
+
+func (ti *treeIndex) Equal(bi index) bool {
+	b := bi.(*treeIndex)
+
+	if ti.tree.Len() != b.tree.Len() {
+		return false
+	}
+
+	equal := true
+
+	ti.tree.Ascend(func(item btree.Item) bool {
+		aki := item.(*keyIndex)
+		bki := b.tree.Get(item).(*keyIndex)
+		if !aki.equal(bki) {
+			equal = false
+			return false
+		}
+		return true
+	})
+
+	return equal
+}
+
+func (ti *treeIndex) Insert(ki *keyIndex) {
+	ti.Lock()
+	defer ti.Unlock()
+	ti.tree.ReplaceOrInsert(ki)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/key_index.go b/vendor/go.etcd.io/etcd/mvcc/key_index.go
new file mode 100644
index 0000000..cf77cb4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/key_index.go
@@ -0,0 +1,402 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+
+	"github.com/google/btree"
+	"go.uber.org/zap"
+)
+
+var (
+	ErrRevisionNotFound = errors.New("mvcc: revision not found")
+)
+
+// keyIndex stores the revisions of a key in the backend.
+// Each keyIndex has at least one key generation.
+// Each generation might have several key versions.
+// Tombstone on a key appends an tombstone version at the end
+// of the current generation and creates a new empty generation.
+// Each version of a key has an index pointing to the backend.
+//
+// For example: put(1.0);put(2.0);tombstone(3.0);put(4.0);tombstone(5.0) on key "foo"
+// generate a keyIndex:
+// key:     "foo"
+// rev: 5
+// generations:
+//    {empty}
+//    {4.0, 5.0(t)}
+//    {1.0, 2.0, 3.0(t)}
+//
+// Compact a keyIndex removes the versions with smaller or equal to
+// rev except the largest one. If the generation becomes empty
+// during compaction, it will be removed. if all the generations get
+// removed, the keyIndex should be removed.
+//
+// For example:
+// compact(2) on the previous example
+// generations:
+//    {empty}
+//    {4.0, 5.0(t)}
+//    {2.0, 3.0(t)}
+//
+// compact(4)
+// generations:
+//    {empty}
+//    {4.0, 5.0(t)}
+//
+// compact(5):
+// generations:
+//    {empty} -> key SHOULD be removed.
+//
+// compact(6):
+// generations:
+//    {empty} -> key SHOULD be removed.
+type keyIndex struct {
+	key         []byte
+	modified    revision // the main rev of the last modification
+	generations []generation
+}
+
+// put puts a revision to the keyIndex.
+func (ki *keyIndex) put(lg *zap.Logger, main int64, sub int64) {
+	rev := revision{main: main, sub: sub}
+
+	if !rev.GreaterThan(ki.modified) {
+		if lg != nil {
+			lg.Panic(
+				"'put' with an unexpected smaller revision",
+				zap.Int64("given-revision-main", rev.main),
+				zap.Int64("given-revision-sub", rev.sub),
+				zap.Int64("modified-revision-main", ki.modified.main),
+				zap.Int64("modified-revision-sub", ki.modified.sub),
+			)
+		} else {
+			plog.Panicf("store.keyindex: put with unexpected smaller revision [%v / %v]", rev, ki.modified)
+		}
+	}
+	if len(ki.generations) == 0 {
+		ki.generations = append(ki.generations, generation{})
+	}
+	g := &ki.generations[len(ki.generations)-1]
+	if len(g.revs) == 0 { // create a new key
+		keysGauge.Inc()
+		g.created = rev
+	}
+	g.revs = append(g.revs, rev)
+	g.ver++
+	ki.modified = rev
+}
+
+func (ki *keyIndex) restore(lg *zap.Logger, created, modified revision, ver int64) {
+	if len(ki.generations) != 0 {
+		if lg != nil {
+			lg.Panic(
+				"'restore' got an unexpected non-empty generations",
+				zap.Int("generations-size", len(ki.generations)),
+			)
+		} else {
+			plog.Panicf("store.keyindex: cannot restore non-empty keyIndex")
+		}
+	}
+
+	ki.modified = modified
+	g := generation{created: created, ver: ver, revs: []revision{modified}}
+	ki.generations = append(ki.generations, g)
+	keysGauge.Inc()
+}
+
+// tombstone puts a revision, pointing to a tombstone, to the keyIndex.
+// It also creates a new empty generation in the keyIndex.
+// It returns ErrRevisionNotFound when tombstone on an empty generation.
+func (ki *keyIndex) tombstone(lg *zap.Logger, main int64, sub int64) error {
+	if ki.isEmpty() {
+		if lg != nil {
+			lg.Panic(
+				"'tombstone' got an unexpected empty keyIndex",
+				zap.String("key", string(ki.key)),
+			)
+		} else {
+			plog.Panicf("store.keyindex: unexpected tombstone on empty keyIndex %s", string(ki.key))
+		}
+	}
+	if ki.generations[len(ki.generations)-1].isEmpty() {
+		return ErrRevisionNotFound
+	}
+	ki.put(lg, main, sub)
+	ki.generations = append(ki.generations, generation{})
+	keysGauge.Dec()
+	return nil
+}
+
+// get gets the modified, created revision and version of the key that satisfies the given atRev.
+// Rev must be higher than or equal to the given atRev.
+func (ki *keyIndex) get(lg *zap.Logger, atRev int64) (modified, created revision, ver int64, err error) {
+	if ki.isEmpty() {
+		if lg != nil {
+			lg.Panic(
+				"'get' got an unexpected empty keyIndex",
+				zap.String("key", string(ki.key)),
+			)
+		} else {
+			plog.Panicf("store.keyindex: unexpected get on empty keyIndex %s", string(ki.key))
+		}
+	}
+	g := ki.findGeneration(atRev)
+	if g.isEmpty() {
+		return revision{}, revision{}, 0, ErrRevisionNotFound
+	}
+
+	n := g.walk(func(rev revision) bool { return rev.main > atRev })
+	if n != -1 {
+		return g.revs[n], g.created, g.ver - int64(len(g.revs)-n-1), nil
+	}
+
+	return revision{}, revision{}, 0, ErrRevisionNotFound
+}
+
+// since returns revisions since the given rev. Only the revision with the
+// largest sub revision will be returned if multiple revisions have the same
+// main revision.
+func (ki *keyIndex) since(lg *zap.Logger, rev int64) []revision {
+	if ki.isEmpty() {
+		if lg != nil {
+			lg.Panic(
+				"'since' got an unexpected empty keyIndex",
+				zap.String("key", string(ki.key)),
+			)
+		} else {
+			plog.Panicf("store.keyindex: unexpected get on empty keyIndex %s", string(ki.key))
+		}
+	}
+	since := revision{rev, 0}
+	var gi int
+	// find the generations to start checking
+	for gi = len(ki.generations) - 1; gi > 0; gi-- {
+		g := ki.generations[gi]
+		if g.isEmpty() {
+			continue
+		}
+		if since.GreaterThan(g.created) {
+			break
+		}
+	}
+
+	var revs []revision
+	var last int64
+	for ; gi < len(ki.generations); gi++ {
+		for _, r := range ki.generations[gi].revs {
+			if since.GreaterThan(r) {
+				continue
+			}
+			if r.main == last {
+				// replace the revision with a new one that has higher sub value,
+				// because the original one should not be seen by external
+				revs[len(revs)-1] = r
+				continue
+			}
+			revs = append(revs, r)
+			last = r.main
+		}
+	}
+	return revs
+}
+
+// compact compacts a keyIndex by removing the versions with smaller or equal
+// revision than the given atRev except the largest one (If the largest one is
+// a tombstone, it will not be kept).
+// If a generation becomes empty during compaction, it will be removed.
+func (ki *keyIndex) compact(lg *zap.Logger, atRev int64, available map[revision]struct{}) {
+	if ki.isEmpty() {
+		if lg != nil {
+			lg.Panic(
+				"'compact' got an unexpected empty keyIndex",
+				zap.String("key", string(ki.key)),
+			)
+		} else {
+			plog.Panicf("store.keyindex: unexpected compact on empty keyIndex %s", string(ki.key))
+		}
+	}
+
+	genIdx, revIndex := ki.doCompact(atRev, available)
+
+	g := &ki.generations[genIdx]
+	if !g.isEmpty() {
+		// remove the previous contents.
+		if revIndex != -1 {
+			g.revs = g.revs[revIndex:]
+		}
+		// remove any tombstone
+		if len(g.revs) == 1 && genIdx != len(ki.generations)-1 {
+			delete(available, g.revs[0])
+			genIdx++
+		}
+	}
+
+	// remove the previous generations.
+	ki.generations = ki.generations[genIdx:]
+}
+
+// keep finds the revision to be kept if compact is called at given atRev.
+func (ki *keyIndex) keep(atRev int64, available map[revision]struct{}) {
+	if ki.isEmpty() {
+		return
+	}
+
+	genIdx, revIndex := ki.doCompact(atRev, available)
+	g := &ki.generations[genIdx]
+	if !g.isEmpty() {
+		// remove any tombstone
+		if revIndex == len(g.revs)-1 && genIdx != len(ki.generations)-1 {
+			delete(available, g.revs[revIndex])
+		}
+	}
+}
+
+func (ki *keyIndex) doCompact(atRev int64, available map[revision]struct{}) (genIdx int, revIndex int) {
+	// walk until reaching the first revision smaller or equal to "atRev",
+	// and add the revision to the available map
+	f := func(rev revision) bool {
+		if rev.main <= atRev {
+			available[rev] = struct{}{}
+			return false
+		}
+		return true
+	}
+
+	genIdx, g := 0, &ki.generations[0]
+	// find first generation includes atRev or created after atRev
+	for genIdx < len(ki.generations)-1 {
+		if tomb := g.revs[len(g.revs)-1].main; tomb > atRev {
+			break
+		}
+		genIdx++
+		g = &ki.generations[genIdx]
+	}
+
+	revIndex = g.walk(f)
+
+	return genIdx, revIndex
+}
+
+func (ki *keyIndex) isEmpty() bool {
+	return len(ki.generations) == 1 && ki.generations[0].isEmpty()
+}
+
+// findGeneration finds out the generation of the keyIndex that the
+// given rev belongs to. If the given rev is at the gap of two generations,
+// which means that the key does not exist at the given rev, it returns nil.
+func (ki *keyIndex) findGeneration(rev int64) *generation {
+	lastg := len(ki.generations) - 1
+	cg := lastg
+
+	for cg >= 0 {
+		if len(ki.generations[cg].revs) == 0 {
+			cg--
+			continue
+		}
+		g := ki.generations[cg]
+		if cg != lastg {
+			if tomb := g.revs[len(g.revs)-1].main; tomb <= rev {
+				return nil
+			}
+		}
+		if g.revs[0].main <= rev {
+			return &ki.generations[cg]
+		}
+		cg--
+	}
+	return nil
+}
+
+func (ki *keyIndex) Less(b btree.Item) bool {
+	return bytes.Compare(ki.key, b.(*keyIndex).key) == -1
+}
+
+func (ki *keyIndex) equal(b *keyIndex) bool {
+	if !bytes.Equal(ki.key, b.key) {
+		return false
+	}
+	if ki.modified != b.modified {
+		return false
+	}
+	if len(ki.generations) != len(b.generations) {
+		return false
+	}
+	for i := range ki.generations {
+		ag, bg := ki.generations[i], b.generations[i]
+		if !ag.equal(bg) {
+			return false
+		}
+	}
+	return true
+}
+
+func (ki *keyIndex) String() string {
+	var s string
+	for _, g := range ki.generations {
+		s += g.String()
+	}
+	return s
+}
+
+// generation contains multiple revisions of a key.
+type generation struct {
+	ver     int64
+	created revision // when the generation is created (put in first revision).
+	revs    []revision
+}
+
+func (g *generation) isEmpty() bool { return g == nil || len(g.revs) == 0 }
+
+// walk walks through the revisions in the generation in descending order.
+// It passes the revision to the given function.
+// walk returns until: 1. it finishes walking all pairs 2. the function returns false.
+// walk returns the position at where it stopped. If it stopped after
+// finishing walking, -1 will be returned.
+func (g *generation) walk(f func(rev revision) bool) int {
+	l := len(g.revs)
+	for i := range g.revs {
+		ok := f(g.revs[l-i-1])
+		if !ok {
+			return l - i - 1
+		}
+	}
+	return -1
+}
+
+func (g *generation) String() string {
+	return fmt.Sprintf("g: created[%d] ver[%d], revs %#v\n", g.created, g.ver, g.revs)
+}
+
+func (g generation) equal(b generation) bool {
+	if g.ver != b.ver {
+		return false
+	}
+	if len(g.revs) != len(b.revs) {
+		return false
+	}
+
+	for i := range g.revs {
+		ar, br := g.revs[i], b.revs[i]
+		if ar != br {
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/kv.go b/vendor/go.etcd.io/etcd/mvcc/kv.go
new file mode 100644
index 0000000..8e898a5
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/kv.go
@@ -0,0 +1,149 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+)
+
+type RangeOptions struct {
+	Limit int64
+	Rev   int64
+	Count bool
+}
+
+type RangeResult struct {
+	KVs   []mvccpb.KeyValue
+	Rev   int64
+	Count int
+}
+
+type ReadView interface {
+	// FirstRev returns the first KV revision at the time of opening the txn.
+	// After a compaction, the first revision increases to the compaction
+	// revision.
+	FirstRev() int64
+
+	// Rev returns the revision of the KV at the time of opening the txn.
+	Rev() int64
+
+	// Range gets the keys in the range at rangeRev.
+	// The returned rev is the current revision of the KV when the operation is executed.
+	// If rangeRev <=0, range gets the keys at currentRev.
+	// If `end` is nil, the request returns the key.
+	// If `end` is not nil and not empty, it gets the keys in range [key, range_end).
+	// If `end` is not nil and empty, it gets the keys greater than or equal to key.
+	// Limit limits the number of keys returned.
+	// If the required rev is compacted, ErrCompacted will be returned.
+	Range(key, end []byte, ro RangeOptions) (r *RangeResult, err error)
+}
+
+// TxnRead represents a read-only transaction with operations that will not
+// block other read transactions.
+type TxnRead interface {
+	ReadView
+	// End marks the transaction is complete and ready to commit.
+	End()
+}
+
+type WriteView interface {
+	// DeleteRange deletes the given range from the store.
+	// A deleteRange increases the rev of the store if any key in the range exists.
+	// The number of key deleted will be returned.
+	// The returned rev is the current revision of the KV when the operation is executed.
+	// It also generates one event for each key delete in the event history.
+	// if the `end` is nil, deleteRange deletes the key.
+	// if the `end` is not nil, deleteRange deletes the keys in range [key, range_end).
+	DeleteRange(key, end []byte) (n, rev int64)
+
+	// Put puts the given key, value into the store. Put also takes additional argument lease to
+	// attach a lease to a key-value pair as meta-data. KV implementation does not validate the lease
+	// id.
+	// A put also increases the rev of the store, and generates one event in the event history.
+	// The returned rev is the current revision of the KV when the operation is executed.
+	Put(key, value []byte, lease lease.LeaseID) (rev int64)
+}
+
+// TxnWrite represents a transaction that can modify the store.
+type TxnWrite interface {
+	TxnRead
+	WriteView
+	// Changes gets the changes made since opening the write txn.
+	Changes() []mvccpb.KeyValue
+}
+
+// txnReadWrite coerces a read txn to a write, panicking on any write operation.
+type txnReadWrite struct{ TxnRead }
+
+func (trw *txnReadWrite) DeleteRange(key, end []byte) (n, rev int64) { panic("unexpected DeleteRange") }
+func (trw *txnReadWrite) Put(key, value []byte, lease lease.LeaseID) (rev int64) {
+	panic("unexpected Put")
+}
+func (trw *txnReadWrite) Changes() []mvccpb.KeyValue { return nil }
+
+func NewReadOnlyTxnWrite(txn TxnRead) TxnWrite { return &txnReadWrite{txn} }
+
+type KV interface {
+	ReadView
+	WriteView
+
+	// Read creates a read transaction.
+	Read() TxnRead
+
+	// Write creates a write transaction.
+	Write() TxnWrite
+
+	// Hash computes the hash of the KV's backend.
+	Hash() (hash uint32, revision int64, err error)
+
+	// HashByRev computes the hash of all MVCC revisions up to a given revision.
+	HashByRev(rev int64) (hash uint32, revision int64, compactRev int64, err error)
+
+	// Compact frees all superseded keys with revisions less than rev.
+	Compact(rev int64) (<-chan struct{}, error)
+
+	// Commit commits outstanding txns into the underlying backend.
+	Commit()
+
+	// Restore restores the KV store from a backend.
+	Restore(b backend.Backend) error
+	Close() error
+}
+
+// WatchableKV is a KV that can be watched.
+type WatchableKV interface {
+	KV
+	Watchable
+}
+
+// Watchable is the interface that wraps the NewWatchStream function.
+type Watchable interface {
+	// NewWatchStream returns a WatchStream that can be used to
+	// watch events happened or happening on the KV.
+	NewWatchStream() WatchStream
+}
+
+// ConsistentWatchableKV is a WatchableKV that understands the consistency
+// algorithm and consistent index.
+// If the consistent index of executing entry is not larger than the
+// consistent index of ConsistentWatchableKV, all operations in
+// this entry are skipped and return empty response.
+type ConsistentWatchableKV interface {
+	WatchableKV
+	// ConsistentIndex returns the current consistent index of the KV.
+	ConsistentIndex() uint64
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/kv_view.go b/vendor/go.etcd.io/etcd/mvcc/kv_view.go
new file mode 100644
index 0000000..bd2e777
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/kv_view.go
@@ -0,0 +1,51 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import "go.etcd.io/etcd/lease"
+
+type readView struct{ kv KV }
+
+func (rv *readView) FirstRev() int64 {
+	tr := rv.kv.Read()
+	defer tr.End()
+	return tr.FirstRev()
+}
+
+func (rv *readView) Rev() int64 {
+	tr := rv.kv.Read()
+	defer tr.End()
+	return tr.Rev()
+}
+
+func (rv *readView) Range(key, end []byte, ro RangeOptions) (r *RangeResult, err error) {
+	tr := rv.kv.Read()
+	defer tr.End()
+	return tr.Range(key, end, ro)
+}
+
+type writeView struct{ kv KV }
+
+func (wv *writeView) DeleteRange(key, end []byte) (n, rev int64) {
+	tw := wv.kv.Write()
+	defer tw.End()
+	return tw.DeleteRange(key, end)
+}
+
+func (wv *writeView) Put(key, value []byte, lease lease.LeaseID) (rev int64) {
+	tw := wv.kv.Write()
+	defer tw.End()
+	return tw.Put(key, value, lease)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/kvstore.go b/vendor/go.etcd.io/etcd/mvcc/kvstore.go
new file mode 100644
index 0000000..e367ebb
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/kvstore.go
@@ -0,0 +1,620 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"hash/crc32"
+	"math"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/pkg/schedule"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+)
+
+var (
+	keyBucketName  = []byte("key")
+	metaBucketName = []byte("meta")
+
+	consistentIndexKeyName  = []byte("consistent_index")
+	scheduledCompactKeyName = []byte("scheduledCompactRev")
+	finishedCompactKeyName  = []byte("finishedCompactRev")
+
+	ErrCompacted = errors.New("mvcc: required revision has been compacted")
+	ErrFutureRev = errors.New("mvcc: required revision is a future revision")
+	ErrCanceled  = errors.New("mvcc: watcher is canceled")
+	ErrClosed    = errors.New("mvcc: closed")
+
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "mvcc")
+)
+
+const (
+	// markedRevBytesLen is the byte length of marked revision.
+	// The first `revBytesLen` bytes represents a normal revision. The last
+	// one byte is the mark.
+	markedRevBytesLen      = revBytesLen + 1
+	markBytePosition       = markedRevBytesLen - 1
+	markTombstone     byte = 't'
+)
+
+var restoreChunkKeys = 10000 // non-const for testing
+var defaultCompactBatchLimit = 1000
+
+// ConsistentIndexGetter is an interface that wraps the Get method.
+// Consistent index is the offset of an entry in a consistent replicated log.
+type ConsistentIndexGetter interface {
+	// ConsistentIndex returns the consistent index of current executing entry.
+	ConsistentIndex() uint64
+}
+
+type StoreConfig struct {
+	CompactionBatchLimit int
+}
+
+type store struct {
+	ReadView
+	WriteView
+
+	// consistentIndex caches the "consistent_index" key's value. Accessed
+	// through atomics so must be 64-bit aligned.
+	consistentIndex uint64
+
+	cfg StoreConfig
+
+	// mu read locks for txns and write locks for non-txn store changes.
+	mu sync.RWMutex
+
+	ig ConsistentIndexGetter
+
+	b       backend.Backend
+	kvindex index
+
+	le lease.Lessor
+
+	// revMuLock protects currentRev and compactMainRev.
+	// Locked at end of write txn and released after write txn unlock lock.
+	// Locked before locking read txn and released after locking.
+	revMu sync.RWMutex
+	// currentRev is the revision of the last completed transaction.
+	currentRev int64
+	// compactMainRev is the main revision of the last compaction.
+	compactMainRev int64
+
+	// bytesBuf8 is a byte slice of length 8
+	// to avoid a repetitive allocation in saveIndex.
+	bytesBuf8 []byte
+
+	fifoSched schedule.Scheduler
+
+	stopc chan struct{}
+
+	lg *zap.Logger
+}
+
+// NewStore returns a new store. It is useful to create a store inside
+// mvcc pkg. It should only be used for testing externally.
+func NewStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) *store {
+	if cfg.CompactionBatchLimit == 0 {
+		cfg.CompactionBatchLimit = defaultCompactBatchLimit
+	}
+	s := &store{
+		cfg:     cfg,
+		b:       b,
+		ig:      ig,
+		kvindex: newTreeIndex(lg),
+
+		le: le,
+
+		currentRev:     1,
+		compactMainRev: -1,
+
+		bytesBuf8: make([]byte, 8),
+		fifoSched: schedule.NewFIFOScheduler(),
+
+		stopc: make(chan struct{}),
+
+		lg: lg,
+	}
+	s.ReadView = &readView{s}
+	s.WriteView = &writeView{s}
+	if s.le != nil {
+		s.le.SetRangeDeleter(func() lease.TxnDelete { return s.Write() })
+	}
+
+	tx := s.b.BatchTx()
+	tx.Lock()
+	tx.UnsafeCreateBucket(keyBucketName)
+	tx.UnsafeCreateBucket(metaBucketName)
+	tx.Unlock()
+	s.b.ForceCommit()
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if err := s.restore(); err != nil {
+		// TODO: return the error instead of panic here?
+		panic("failed to recover store from backend")
+	}
+
+	return s
+}
+
+func (s *store) compactBarrier(ctx context.Context, ch chan struct{}) {
+	if ctx == nil || ctx.Err() != nil {
+		s.mu.Lock()
+		select {
+		case <-s.stopc:
+		default:
+			f := func(ctx context.Context) { s.compactBarrier(ctx, ch) }
+			s.fifoSched.Schedule(f)
+		}
+		s.mu.Unlock()
+		return
+	}
+	close(ch)
+}
+
+func (s *store) Hash() (hash uint32, revision int64, err error) {
+	// TODO: hash and revision could be inconsistent, one possible fix is to add s.revMu.RLock() at the beginning of function, which is costly
+	start := time.Now()
+
+	s.b.ForceCommit()
+	h, err := s.b.Hash(DefaultIgnores)
+
+	hashSec.Observe(time.Since(start).Seconds())
+	return h, s.currentRev, err
+}
+
+func (s *store) HashByRev(rev int64) (hash uint32, currentRev int64, compactRev int64, err error) {
+	start := time.Now()
+
+	s.mu.RLock()
+	s.revMu.RLock()
+	compactRev, currentRev = s.compactMainRev, s.currentRev
+	s.revMu.RUnlock()
+
+	if rev > 0 && rev <= compactRev {
+		s.mu.RUnlock()
+		return 0, 0, compactRev, ErrCompacted
+	} else if rev > 0 && rev > currentRev {
+		s.mu.RUnlock()
+		return 0, currentRev, 0, ErrFutureRev
+	}
+
+	if rev == 0 {
+		rev = currentRev
+	}
+	keep := s.kvindex.Keep(rev)
+
+	tx := s.b.ReadTx()
+	tx.RLock()
+	defer tx.RUnlock()
+	s.mu.RUnlock()
+
+	upper := revision{main: rev + 1}
+	lower := revision{main: compactRev + 1}
+	h := crc32.New(crc32.MakeTable(crc32.Castagnoli))
+
+	h.Write(keyBucketName)
+	err = tx.UnsafeForEach(keyBucketName, func(k, v []byte) error {
+		kr := bytesToRev(k)
+		if !upper.GreaterThan(kr) {
+			return nil
+		}
+		// skip revisions that are scheduled for deletion
+		// due to compacting; don't skip if there isn't one.
+		if lower.GreaterThan(kr) && len(keep) > 0 {
+			if _, ok := keep[kr]; !ok {
+				return nil
+			}
+		}
+		h.Write(k)
+		h.Write(v)
+		return nil
+	})
+	hash = h.Sum32()
+
+	hashRevSec.Observe(time.Since(start).Seconds())
+	return hash, currentRev, compactRev, err
+}
+
+func (s *store) updateCompactRev(rev int64) (<-chan struct{}, error) {
+	s.revMu.Lock()
+	if rev <= s.compactMainRev {
+		ch := make(chan struct{})
+		f := func(ctx context.Context) { s.compactBarrier(ctx, ch) }
+		s.fifoSched.Schedule(f)
+		s.revMu.Unlock()
+		return ch, ErrCompacted
+	}
+	if rev > s.currentRev {
+		s.revMu.Unlock()
+		return nil, ErrFutureRev
+	}
+
+	s.compactMainRev = rev
+
+	rbytes := newRevBytes()
+	revToBytes(revision{main: rev}, rbytes)
+
+	tx := s.b.BatchTx()
+	tx.Lock()
+	tx.UnsafePut(metaBucketName, scheduledCompactKeyName, rbytes)
+	tx.Unlock()
+	// ensure that desired compaction is persisted
+	s.b.ForceCommit()
+
+	s.revMu.Unlock()
+
+	return nil, nil
+}
+
+func (s *store) compact(rev int64) (<-chan struct{}, error) {
+	start := time.Now()
+	keep := s.kvindex.Compact(rev)
+	ch := make(chan struct{})
+	var j = func(ctx context.Context) {
+		if ctx.Err() != nil {
+			s.compactBarrier(ctx, ch)
+			return
+		}
+		if !s.scheduleCompaction(rev, keep) {
+			s.compactBarrier(nil, ch)
+			return
+		}
+		close(ch)
+	}
+
+	s.fifoSched.Schedule(j)
+
+	indexCompactionPauseMs.Observe(float64(time.Since(start) / time.Millisecond))
+	return ch, nil
+}
+
+func (s *store) compactLockfree(rev int64) (<-chan struct{}, error) {
+	ch, err := s.updateCompactRev(rev)
+	if nil != err {
+		return ch, err
+	}
+
+	return s.compact(rev)
+}
+
+func (s *store) Compact(rev int64) (<-chan struct{}, error) {
+	s.mu.Lock()
+
+	ch, err := s.updateCompactRev(rev)
+
+	if err != nil {
+		s.mu.Unlock()
+		return ch, err
+	}
+	s.mu.Unlock()
+
+	return s.compact(rev)
+}
+
+// DefaultIgnores is a map of keys to ignore in hash checking.
+var DefaultIgnores map[backend.IgnoreKey]struct{}
+
+func init() {
+	DefaultIgnores = map[backend.IgnoreKey]struct{}{
+		// consistent index might be changed due to v2 internal sync, which
+		// is not controllable by the user.
+		{Bucket: string(metaBucketName), Key: string(consistentIndexKeyName)}: {},
+	}
+}
+
+func (s *store) Commit() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	tx := s.b.BatchTx()
+	tx.Lock()
+	s.saveIndex(tx)
+	tx.Unlock()
+	s.b.ForceCommit()
+}
+
+func (s *store) Restore(b backend.Backend) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	close(s.stopc)
+	s.fifoSched.Stop()
+
+	atomic.StoreUint64(&s.consistentIndex, 0)
+	s.b = b
+	s.kvindex = newTreeIndex(s.lg)
+	s.currentRev = 1
+	s.compactMainRev = -1
+	s.fifoSched = schedule.NewFIFOScheduler()
+	s.stopc = make(chan struct{})
+
+	return s.restore()
+}
+
+func (s *store) restore() error {
+	s.setupMetricsReporter()
+
+	min, max := newRevBytes(), newRevBytes()
+	revToBytes(revision{main: 1}, min)
+	revToBytes(revision{main: math.MaxInt64, sub: math.MaxInt64}, max)
+
+	keyToLease := make(map[string]lease.LeaseID)
+
+	// restore index
+	tx := s.b.BatchTx()
+	tx.Lock()
+
+	_, finishedCompactBytes := tx.UnsafeRange(metaBucketName, finishedCompactKeyName, nil, 0)
+	if len(finishedCompactBytes) != 0 {
+		s.compactMainRev = bytesToRev(finishedCompactBytes[0]).main
+
+		if s.lg != nil {
+			s.lg.Info(
+				"restored last compact revision",
+				zap.String("meta-bucket-name", string(metaBucketName)),
+				zap.String("meta-bucket-name-key", string(finishedCompactKeyName)),
+				zap.Int64("restored-compact-revision", s.compactMainRev),
+			)
+		} else {
+			plog.Printf("restore compact to %d", s.compactMainRev)
+		}
+	}
+	_, scheduledCompactBytes := tx.UnsafeRange(metaBucketName, scheduledCompactKeyName, nil, 0)
+	scheduledCompact := int64(0)
+	if len(scheduledCompactBytes) != 0 {
+		scheduledCompact = bytesToRev(scheduledCompactBytes[0]).main
+	}
+
+	// index keys concurrently as they're loaded in from tx
+	keysGauge.Set(0)
+	rkvc, revc := restoreIntoIndex(s.lg, s.kvindex)
+	for {
+		keys, vals := tx.UnsafeRange(keyBucketName, min, max, int64(restoreChunkKeys))
+		if len(keys) == 0 {
+			break
+		}
+		// rkvc blocks if the total pending keys exceeds the restore
+		// chunk size to keep keys from consuming too much memory.
+		restoreChunk(s.lg, rkvc, keys, vals, keyToLease)
+		if len(keys) < restoreChunkKeys {
+			// partial set implies final set
+			break
+		}
+		// next set begins after where this one ended
+		newMin := bytesToRev(keys[len(keys)-1][:revBytesLen])
+		newMin.sub++
+		revToBytes(newMin, min)
+	}
+	close(rkvc)
+	s.currentRev = <-revc
+
+	// keys in the range [compacted revision -N, compaction] might all be deleted due to compaction.
+	// the correct revision should be set to compaction revision in the case, not the largest revision
+	// we have seen.
+	if s.currentRev < s.compactMainRev {
+		s.currentRev = s.compactMainRev
+	}
+	if scheduledCompact <= s.compactMainRev {
+		scheduledCompact = 0
+	}
+
+	for key, lid := range keyToLease {
+		if s.le == nil {
+			panic("no lessor to attach lease")
+		}
+		err := s.le.Attach(lid, []lease.LeaseItem{{Key: key}})
+		if err != nil {
+			if s.lg != nil {
+				s.lg.Warn(
+					"failed to attach a lease",
+					zap.String("lease-id", fmt.Sprintf("%016x", lid)),
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("unexpected Attach error: %v", err)
+			}
+		}
+	}
+
+	tx.Unlock()
+
+	if scheduledCompact != 0 {
+		s.compactLockfree(scheduledCompact)
+
+		if s.lg != nil {
+			s.lg.Info(
+				"resume scheduled compaction",
+				zap.String("meta-bucket-name", string(metaBucketName)),
+				zap.String("meta-bucket-name-key", string(scheduledCompactKeyName)),
+				zap.Int64("scheduled-compact-revision", scheduledCompact),
+			)
+		} else {
+			plog.Printf("resume scheduled compaction at %d", scheduledCompact)
+		}
+	}
+
+	return nil
+}
+
+type revKeyValue struct {
+	key  []byte
+	kv   mvccpb.KeyValue
+	kstr string
+}
+
+func restoreIntoIndex(lg *zap.Logger, idx index) (chan<- revKeyValue, <-chan int64) {
+	rkvc, revc := make(chan revKeyValue, restoreChunkKeys), make(chan int64, 1)
+	go func() {
+		currentRev := int64(1)
+		defer func() { revc <- currentRev }()
+		// restore the tree index from streaming the unordered index.
+		kiCache := make(map[string]*keyIndex, restoreChunkKeys)
+		for rkv := range rkvc {
+			ki, ok := kiCache[rkv.kstr]
+			// purge kiCache if many keys but still missing in the cache
+			if !ok && len(kiCache) >= restoreChunkKeys {
+				i := 10
+				for k := range kiCache {
+					delete(kiCache, k)
+					if i--; i == 0 {
+						break
+					}
+				}
+			}
+			// cache miss, fetch from tree index if there
+			if !ok {
+				ki = &keyIndex{key: rkv.kv.Key}
+				if idxKey := idx.KeyIndex(ki); idxKey != nil {
+					kiCache[rkv.kstr], ki = idxKey, idxKey
+					ok = true
+				}
+			}
+			rev := bytesToRev(rkv.key)
+			currentRev = rev.main
+			if ok {
+				if isTombstone(rkv.key) {
+					ki.tombstone(lg, rev.main, rev.sub)
+					continue
+				}
+				ki.put(lg, rev.main, rev.sub)
+			} else if !isTombstone(rkv.key) {
+				ki.restore(lg, revision{rkv.kv.CreateRevision, 0}, rev, rkv.kv.Version)
+				idx.Insert(ki)
+				kiCache[rkv.kstr] = ki
+			}
+		}
+	}()
+	return rkvc, revc
+}
+
+func restoreChunk(lg *zap.Logger, kvc chan<- revKeyValue, keys, vals [][]byte, keyToLease map[string]lease.LeaseID) {
+	for i, key := range keys {
+		rkv := revKeyValue{key: key}
+		if err := rkv.kv.Unmarshal(vals[i]); err != nil {
+			if lg != nil {
+				lg.Fatal("failed to unmarshal mvccpb.KeyValue", zap.Error(err))
+			} else {
+				plog.Fatalf("cannot unmarshal event: %v", err)
+			}
+		}
+		rkv.kstr = string(rkv.kv.Key)
+		if isTombstone(key) {
+			delete(keyToLease, rkv.kstr)
+		} else if lid := lease.LeaseID(rkv.kv.Lease); lid != lease.NoLease {
+			keyToLease[rkv.kstr] = lid
+		} else {
+			delete(keyToLease, rkv.kstr)
+		}
+		kvc <- rkv
+	}
+}
+
+func (s *store) Close() error {
+	close(s.stopc)
+	s.fifoSched.Stop()
+	return nil
+}
+
+func (s *store) saveIndex(tx backend.BatchTx) {
+	if s.ig == nil {
+		return
+	}
+	bs := s.bytesBuf8
+	ci := s.ig.ConsistentIndex()
+	binary.BigEndian.PutUint64(bs, ci)
+	// put the index into the underlying backend
+	// tx has been locked in TxnBegin, so there is no need to lock it again
+	tx.UnsafePut(metaBucketName, consistentIndexKeyName, bs)
+	atomic.StoreUint64(&s.consistentIndex, ci)
+}
+
+func (s *store) ConsistentIndex() uint64 {
+	if ci := atomic.LoadUint64(&s.consistentIndex); ci > 0 {
+		return ci
+	}
+	tx := s.b.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+	_, vs := tx.UnsafeRange(metaBucketName, consistentIndexKeyName, nil, 0)
+	if len(vs) == 0 {
+		return 0
+	}
+	v := binary.BigEndian.Uint64(vs[0])
+	atomic.StoreUint64(&s.consistentIndex, v)
+	return v
+}
+
+func (s *store) setupMetricsReporter() {
+	b := s.b
+	reportDbTotalSizeInBytesMu.Lock()
+	reportDbTotalSizeInBytes = func() float64 { return float64(b.Size()) }
+	reportDbTotalSizeInBytesMu.Unlock()
+	reportDbTotalSizeInBytesDebugMu.Lock()
+	reportDbTotalSizeInBytesDebug = func() float64 { return float64(b.Size()) }
+	reportDbTotalSizeInBytesDebugMu.Unlock()
+	reportDbTotalSizeInUseInBytesMu.Lock()
+	reportDbTotalSizeInUseInBytes = func() float64 { return float64(b.SizeInUse()) }
+	reportDbTotalSizeInUseInBytesMu.Unlock()
+	reportDbOpenReadTxNMu.Lock()
+	reportDbOpenReadTxN = func() float64 { return float64(b.OpenReadTxN()) }
+	reportDbOpenReadTxNMu.Unlock()
+	reportCurrentRevMu.Lock()
+	reportCurrentRev = func() float64 {
+		s.revMu.RLock()
+		defer s.revMu.RUnlock()
+		return float64(s.currentRev)
+	}
+	reportCurrentRevMu.Unlock()
+	reportCompactRevMu.Lock()
+	reportCompactRev = func() float64 {
+		s.revMu.RLock()
+		defer s.revMu.RUnlock()
+		return float64(s.compactMainRev)
+	}
+	reportCompactRevMu.Unlock()
+}
+
+// appendMarkTombstone appends tombstone mark to normal revision bytes.
+func appendMarkTombstone(lg *zap.Logger, b []byte) []byte {
+	if len(b) != revBytesLen {
+		if lg != nil {
+			lg.Panic(
+				"cannot append tombstone mark to non-normal revision bytes",
+				zap.Int("expected-revision-bytes-size", revBytesLen),
+				zap.Int("given-revision-bytes-size", len(b)),
+			)
+		} else {
+			plog.Panicf("cannot append mark to non normal revision bytes")
+		}
+	}
+	return append(b, markTombstone)
+}
+
+// isTombstone checks whether the revision bytes is a tombstone.
+func isTombstone(b []byte) bool {
+	return len(b) == markedRevBytesLen && b[markBytePosition] == markTombstone
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/kvstore_compaction.go b/vendor/go.etcd.io/etcd/mvcc/kvstore_compaction.go
new file mode 100644
index 0000000..2adb498
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/kvstore_compaction.go
@@ -0,0 +1,79 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"encoding/binary"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+func (s *store) scheduleCompaction(compactMainRev int64, keep map[revision]struct{}) bool {
+	totalStart := time.Now()
+	defer func() { dbCompactionTotalMs.Observe(float64(time.Since(totalStart) / time.Millisecond)) }()
+	keyCompactions := 0
+	defer func() { dbCompactionKeysCounter.Add(float64(keyCompactions)) }()
+
+	end := make([]byte, 8)
+	binary.BigEndian.PutUint64(end, uint64(compactMainRev+1))
+
+	last := make([]byte, 8+1+8)
+	for {
+		var rev revision
+
+		start := time.Now()
+
+		tx := s.b.BatchTx()
+		tx.Lock()
+		keys, _ := tx.UnsafeRange(keyBucketName, last, end, int64(s.cfg.CompactionBatchLimit))
+		for _, key := range keys {
+			rev = bytesToRev(key)
+			if _, ok := keep[rev]; !ok {
+				tx.UnsafeDelete(keyBucketName, key)
+			}
+		}
+
+		if len(keys) < s.cfg.CompactionBatchLimit {
+			rbytes := make([]byte, 8+1+8)
+			revToBytes(revision{main: compactMainRev}, rbytes)
+			tx.UnsafePut(metaBucketName, finishedCompactKeyName, rbytes)
+			tx.Unlock()
+			if s.lg != nil {
+				s.lg.Info(
+					"finished scheduled compaction",
+					zap.Int64("compact-revision", compactMainRev),
+					zap.Duration("took", time.Since(totalStart)),
+				)
+			} else {
+				plog.Infof("finished scheduled compaction at %d (took %v)", compactMainRev, time.Since(totalStart))
+			}
+			return true
+		}
+
+		// update last
+		revToBytes(revision{main: rev.main, sub: rev.sub + 1}, last)
+		tx.Unlock()
+		// Immediately commit the compaction deletes instead of letting them accumulate in the write buffer
+		s.b.ForceCommit()
+		dbCompactionPauseMs.Observe(float64(time.Since(start) / time.Millisecond))
+
+		select {
+		case <-time.After(10 * time.Millisecond):
+		case <-s.stopc:
+			return false
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/kvstore_txn.go b/vendor/go.etcd.io/etcd/mvcc/kvstore_txn.go
new file mode 100644
index 0000000..9698254
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/kvstore_txn.go
@@ -0,0 +1,313 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.uber.org/zap"
+)
+
+type storeTxnRead struct {
+	s  *store
+	tx backend.ReadTx
+
+	firstRev int64
+	rev      int64
+}
+
+func (s *store) Read() TxnRead {
+	s.mu.RLock()
+	s.revMu.RLock()
+	// backend holds b.readTx.RLock() only when creating the concurrentReadTx. After
+	// ConcurrentReadTx is created, it will not block write transaction.
+	tx := s.b.ConcurrentReadTx()
+	tx.RLock() // RLock is no-op. concurrentReadTx does not need to be locked after it is created.
+	firstRev, rev := s.compactMainRev, s.currentRev
+	s.revMu.RUnlock()
+	return newMetricsTxnRead(&storeTxnRead{s, tx, firstRev, rev})
+}
+
+func (tr *storeTxnRead) FirstRev() int64 { return tr.firstRev }
+func (tr *storeTxnRead) Rev() int64      { return tr.rev }
+
+func (tr *storeTxnRead) Range(key, end []byte, ro RangeOptions) (r *RangeResult, err error) {
+	return tr.rangeKeys(key, end, tr.Rev(), ro)
+}
+
+func (tr *storeTxnRead) End() {
+	tr.tx.RUnlock() // RUnlock signals the end of concurrentReadTx.
+	tr.s.mu.RUnlock()
+}
+
+type storeTxnWrite struct {
+	storeTxnRead
+	tx backend.BatchTx
+	// beginRev is the revision where the txn begins; it will write to the next revision.
+	beginRev int64
+	changes  []mvccpb.KeyValue
+}
+
+func (s *store) Write() TxnWrite {
+	s.mu.RLock()
+	tx := s.b.BatchTx()
+	tx.Lock()
+	tw := &storeTxnWrite{
+		storeTxnRead: storeTxnRead{s, tx, 0, 0},
+		tx:           tx,
+		beginRev:     s.currentRev,
+		changes:      make([]mvccpb.KeyValue, 0, 4),
+	}
+	return newMetricsTxnWrite(tw)
+}
+
+func (tw *storeTxnWrite) Rev() int64 { return tw.beginRev }
+
+func (tw *storeTxnWrite) Range(key, end []byte, ro RangeOptions) (r *RangeResult, err error) {
+	rev := tw.beginRev
+	if len(tw.changes) > 0 {
+		rev++
+	}
+	return tw.rangeKeys(key, end, rev, ro)
+}
+
+func (tw *storeTxnWrite) DeleteRange(key, end []byte) (int64, int64) {
+	if n := tw.deleteRange(key, end); n != 0 || len(tw.changes) > 0 {
+		return n, tw.beginRev + 1
+	}
+	return 0, tw.beginRev
+}
+
+func (tw *storeTxnWrite) Put(key, value []byte, lease lease.LeaseID) int64 {
+	tw.put(key, value, lease)
+	return tw.beginRev + 1
+}
+
+func (tw *storeTxnWrite) End() {
+	// only update index if the txn modifies the mvcc state.
+	if len(tw.changes) != 0 {
+		tw.s.saveIndex(tw.tx)
+		// hold revMu lock to prevent new read txns from opening until writeback.
+		tw.s.revMu.Lock()
+		tw.s.currentRev++
+	}
+	tw.tx.Unlock()
+	if len(tw.changes) != 0 {
+		tw.s.revMu.Unlock()
+	}
+	tw.s.mu.RUnlock()
+}
+
+func (tr *storeTxnRead) rangeKeys(key, end []byte, curRev int64, ro RangeOptions) (*RangeResult, error) {
+	rev := ro.Rev
+	if rev > curRev {
+		return &RangeResult{KVs: nil, Count: -1, Rev: curRev}, ErrFutureRev
+	}
+	if rev <= 0 {
+		rev = curRev
+	}
+	if rev < tr.s.compactMainRev {
+		return &RangeResult{KVs: nil, Count: -1, Rev: 0}, ErrCompacted
+	}
+
+	revpairs := tr.s.kvindex.Revisions(key, end, rev)
+	if len(revpairs) == 0 {
+		return &RangeResult{KVs: nil, Count: 0, Rev: curRev}, nil
+	}
+	if ro.Count {
+		return &RangeResult{KVs: nil, Count: len(revpairs), Rev: curRev}, nil
+	}
+
+	limit := int(ro.Limit)
+	if limit <= 0 || limit > len(revpairs) {
+		limit = len(revpairs)
+	}
+
+	kvs := make([]mvccpb.KeyValue, limit)
+	revBytes := newRevBytes()
+	for i, revpair := range revpairs[:len(kvs)] {
+		revToBytes(revpair, revBytes)
+		_, vs := tr.tx.UnsafeRange(keyBucketName, revBytes, nil, 0)
+		if len(vs) != 1 {
+			if tr.s.lg != nil {
+				tr.s.lg.Fatal(
+					"range failed to find revision pair",
+					zap.Int64("revision-main", revpair.main),
+					zap.Int64("revision-sub", revpair.sub),
+				)
+			} else {
+				plog.Fatalf("range cannot find rev (%d,%d)", revpair.main, revpair.sub)
+			}
+		}
+		if err := kvs[i].Unmarshal(vs[0]); err != nil {
+			if tr.s.lg != nil {
+				tr.s.lg.Fatal(
+					"failed to unmarshal mvccpb.KeyValue",
+					zap.Error(err),
+				)
+			} else {
+				plog.Fatalf("cannot unmarshal event: %v", err)
+			}
+		}
+	}
+	return &RangeResult{KVs: kvs, Count: len(revpairs), Rev: curRev}, nil
+}
+
+func (tw *storeTxnWrite) put(key, value []byte, leaseID lease.LeaseID) {
+	rev := tw.beginRev + 1
+	c := rev
+	oldLease := lease.NoLease
+
+	// if the key exists before, use its previous created and
+	// get its previous leaseID
+	_, created, ver, err := tw.s.kvindex.Get(key, rev)
+	if err == nil {
+		c = created.main
+		oldLease = tw.s.le.GetLease(lease.LeaseItem{Key: string(key)})
+	}
+
+	ibytes := newRevBytes()
+	idxRev := revision{main: rev, sub: int64(len(tw.changes))}
+	revToBytes(idxRev, ibytes)
+
+	ver = ver + 1
+	kv := mvccpb.KeyValue{
+		Key:            key,
+		Value:          value,
+		CreateRevision: c,
+		ModRevision:    rev,
+		Version:        ver,
+		Lease:          int64(leaseID),
+	}
+
+	d, err := kv.Marshal()
+	if err != nil {
+		if tw.storeTxnRead.s.lg != nil {
+			tw.storeTxnRead.s.lg.Fatal(
+				"failed to marshal mvccpb.KeyValue",
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot marshal event: %v", err)
+		}
+	}
+
+	tw.tx.UnsafeSeqPut(keyBucketName, ibytes, d)
+	tw.s.kvindex.Put(key, idxRev)
+	tw.changes = append(tw.changes, kv)
+
+	if oldLease != lease.NoLease {
+		if tw.s.le == nil {
+			panic("no lessor to detach lease")
+		}
+		err = tw.s.le.Detach(oldLease, []lease.LeaseItem{{Key: string(key)}})
+		if err != nil {
+			if tw.storeTxnRead.s.lg != nil {
+				tw.storeTxnRead.s.lg.Fatal(
+					"failed to detach old lease from a key",
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("unexpected error from lease detach: %v", err)
+			}
+		}
+	}
+	if leaseID != lease.NoLease {
+		if tw.s.le == nil {
+			panic("no lessor to attach lease")
+		}
+		err = tw.s.le.Attach(leaseID, []lease.LeaseItem{{Key: string(key)}})
+		if err != nil {
+			panic("unexpected error from lease Attach")
+		}
+	}
+}
+
+func (tw *storeTxnWrite) deleteRange(key, end []byte) int64 {
+	rrev := tw.beginRev
+	if len(tw.changes) > 0 {
+		rrev++
+	}
+	keys, _ := tw.s.kvindex.Range(key, end, rrev)
+	if len(keys) == 0 {
+		return 0
+	}
+	for _, key := range keys {
+		tw.delete(key)
+	}
+	return int64(len(keys))
+}
+
+func (tw *storeTxnWrite) delete(key []byte) {
+	ibytes := newRevBytes()
+	idxRev := revision{main: tw.beginRev + 1, sub: int64(len(tw.changes))}
+	revToBytes(idxRev, ibytes)
+
+	if tw.storeTxnRead.s != nil && tw.storeTxnRead.s.lg != nil {
+		ibytes = appendMarkTombstone(tw.storeTxnRead.s.lg, ibytes)
+	} else {
+		// TODO: remove this in v3.5
+		ibytes = appendMarkTombstone(nil, ibytes)
+	}
+
+	kv := mvccpb.KeyValue{Key: key}
+
+	d, err := kv.Marshal()
+	if err != nil {
+		if tw.storeTxnRead.s.lg != nil {
+			tw.storeTxnRead.s.lg.Fatal(
+				"failed to marshal mvccpb.KeyValue",
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot marshal event: %v", err)
+		}
+	}
+
+	tw.tx.UnsafeSeqPut(keyBucketName, ibytes, d)
+	err = tw.s.kvindex.Tombstone(key, idxRev)
+	if err != nil {
+		if tw.storeTxnRead.s.lg != nil {
+			tw.storeTxnRead.s.lg.Fatal(
+				"failed to tombstone an existing key",
+				zap.String("key", string(key)),
+				zap.Error(err),
+			)
+		} else {
+			plog.Fatalf("cannot tombstone an existing key (%s): %v", string(key), err)
+		}
+	}
+	tw.changes = append(tw.changes, kv)
+
+	item := lease.LeaseItem{Key: string(key)}
+	leaseID := tw.s.le.GetLease(item)
+
+	if leaseID != lease.NoLease {
+		err = tw.s.le.Detach(leaseID, []lease.LeaseItem{item})
+		if err != nil {
+			if tw.storeTxnRead.s.lg != nil {
+				tw.storeTxnRead.s.lg.Fatal(
+					"failed to detach old lease from a key",
+					zap.Error(err),
+				)
+			} else {
+				plog.Errorf("cannot detach %v", err)
+			}
+		}
+	}
+}
+
+func (tw *storeTxnWrite) Changes() []mvccpb.KeyValue { return tw.changes }
diff --git a/vendor/go.etcd.io/etcd/mvcc/metrics.go b/vendor/go.etcd.io/etcd/mvcc/metrics.go
new file mode 100644
index 0000000..7526ee4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/metrics.go
@@ -0,0 +1,336 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"sync"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	rangeCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "range_total",
+			Help:      "Total number of ranges seen by this member.",
+		})
+	rangeCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "range_total",
+			Help:      "Total number of ranges seen by this member.",
+		})
+
+	putCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "put_total",
+			Help:      "Total number of puts seen by this member.",
+		})
+	// TODO: remove in 3.5 release
+	putCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "put_total",
+			Help:      "Total number of puts seen by this member.",
+		})
+
+	deleteCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "delete_total",
+			Help:      "Total number of deletes seen by this member.",
+		})
+	// TODO: remove in 3.5 release
+	deleteCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "delete_total",
+			Help:      "Total number of deletes seen by this member.",
+		})
+
+	txnCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd",
+			Subsystem: "mvcc",
+			Name:      "txn_total",
+			Help:      "Total number of txns seen by this member.",
+		})
+	txnCounterDebug = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "txn_total",
+			Help:      "Total number of txns seen by this member.",
+		})
+
+	keysGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "keys_total",
+			Help:      "Total number of keys.",
+		})
+
+	watchStreamGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "watch_stream_total",
+			Help:      "Total number of watch streams.",
+		})
+
+	watcherGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "watcher_total",
+			Help:      "Total number of watchers.",
+		})
+
+	slowWatcherGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "slow_watcher_total",
+			Help:      "Total number of unsynced slow watchers.",
+		})
+
+	totalEventsCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "events_total",
+			Help:      "Total number of events sent by this member.",
+		})
+
+	pendingEventsGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "pending_events_total",
+			Help:      "Total number of pending events to be sent.",
+		})
+
+	indexCompactionPauseMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "index_compaction_pause_duration_milliseconds",
+			Help:      "Bucketed histogram of index compaction pause duration.",
+
+			// lowest bucket start of upper bound 0.5 ms with factor 2
+			// highest bucket start of 0.5 ms * 2^13 == 4.096 sec
+			Buckets: prometheus.ExponentialBuckets(0.5, 2, 14),
+		})
+
+	dbCompactionPauseMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_pause_duration_milliseconds",
+			Help:      "Bucketed histogram of db compaction pause duration.",
+
+			// lowest bucket start of upper bound 1 ms with factor 2
+			// highest bucket start of 1 ms * 2^12 == 4.096 sec
+			Buckets: prometheus.ExponentialBuckets(1, 2, 13),
+		})
+
+	dbCompactionTotalMs = prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_total_duration_milliseconds",
+			Help:      "Bucketed histogram of db compaction total duration.",
+
+			// lowest bucket start of upper bound 100 ms with factor 2
+			// highest bucket start of 100 ms * 2^13 == 8.192 sec
+			Buckets: prometheus.ExponentialBuckets(100, 2, 14),
+		})
+
+	dbCompactionKeysCounter = prometheus.NewCounter(
+		prometheus.CounterOpts{
+			Namespace: "etcd_debugging",
+			Subsystem: "mvcc",
+			Name:      "db_compaction_keys_total",
+			Help:      "Total number of db keys compacted.",
+		})
+
+	dbTotalSize = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_bytes",
+		Help:      "Total size of the underlying database physically allocated in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInBytesMu.RLock()
+			defer reportDbTotalSizeInBytesMu.RUnlock()
+			return reportDbTotalSizeInBytes()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInBytesMu sync.RWMutex
+	reportDbTotalSizeInBytes   = func() float64 { return 0 }
+
+	// TODO: remove this in v3.5
+	dbTotalSizeDebug = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_bytes",
+		Help:      "Total size of the underlying database physically allocated in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInBytesDebugMu.RLock()
+			defer reportDbTotalSizeInBytesDebugMu.RUnlock()
+			return reportDbTotalSizeInBytesDebug()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInBytesDebugMu sync.RWMutex
+	reportDbTotalSizeInBytesDebug   = func() float64 { return 0 }
+
+	dbTotalSizeInUse = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_use_in_bytes",
+		Help:      "Total size of the underlying database logically in use in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInUseInBytesMu.RLock()
+			defer reportDbTotalSizeInUseInBytesMu.RUnlock()
+			return reportDbTotalSizeInUseInBytes()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInUseInBytesMu sync.RWMutex
+	reportDbTotalSizeInUseInBytes   = func() float64 { return 0 }
+
+	dbOpenReadTxN = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "db_open_read_transactions",
+		Help:      "The number of currently open read transactions",
+	},
+
+		func() float64 {
+			reportDbOpenReadTxNMu.RLock()
+			defer reportDbOpenReadTxNMu.RUnlock()
+			return reportDbOpenReadTxN()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbOpenReadTxNMu sync.RWMutex
+	reportDbOpenReadTxN   = func() float64 { return 0 }
+
+	hashSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "hash_duration_seconds",
+		Help:      "The latency distribution of storage hash operation.",
+
+		// 100 MB usually takes 100 ms, so start with 10 MB of 10 ms
+		// lowest bucket start of upper bound 0.01 sec (10 ms) with factor 2
+		// highest bucket start of 0.01 sec * 2^14 == 163.84 sec
+		Buckets: prometheus.ExponentialBuckets(.01, 2, 15),
+	})
+
+	hashRevSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "mvcc",
+		Name:      "hash_rev_duration_seconds",
+		Help:      "The latency distribution of storage hash by revision operation.",
+
+		// 100 MB usually takes 100 ms, so start with 10 MB of 10 ms
+		// lowest bucket start of upper bound 0.01 sec (10 ms) with factor 2
+		// highest bucket start of 0.01 sec * 2^14 == 163.84 sec
+		Buckets: prometheus.ExponentialBuckets(.01, 2, 15),
+	})
+
+	currentRev = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "current_revision",
+		Help:      "The current revision of store.",
+	},
+		func() float64 {
+			reportCurrentRevMu.RLock()
+			defer reportCurrentRevMu.RUnlock()
+			return reportCurrentRev()
+		},
+	)
+	// overridden by mvcc initialization
+	reportCurrentRevMu sync.RWMutex
+	reportCurrentRev   = func() float64 { return 0 }
+
+	compactRev = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "compact_revision",
+		Help:      "The revision of the last compaction in store.",
+	},
+		func() float64 {
+			reportCompactRevMu.RLock()
+			defer reportCompactRevMu.RUnlock()
+			return reportCompactRev()
+		},
+	)
+	// overridden by mvcc initialization
+	reportCompactRevMu sync.RWMutex
+	reportCompactRev   = func() float64 { return 0 }
+)
+
+func init() {
+	prometheus.MustRegister(rangeCounter)
+	prometheus.MustRegister(rangeCounterDebug)
+	prometheus.MustRegister(putCounter)
+	prometheus.MustRegister(putCounterDebug)
+	prometheus.MustRegister(deleteCounter)
+	prometheus.MustRegister(deleteCounterDebug)
+	prometheus.MustRegister(txnCounter)
+	prometheus.MustRegister(txnCounterDebug)
+	prometheus.MustRegister(keysGauge)
+	prometheus.MustRegister(watchStreamGauge)
+	prometheus.MustRegister(watcherGauge)
+	prometheus.MustRegister(slowWatcherGauge)
+	prometheus.MustRegister(totalEventsCounter)
+	prometheus.MustRegister(pendingEventsGauge)
+	prometheus.MustRegister(indexCompactionPauseMs)
+	prometheus.MustRegister(dbCompactionPauseMs)
+	prometheus.MustRegister(dbCompactionTotalMs)
+	prometheus.MustRegister(dbCompactionKeysCounter)
+	prometheus.MustRegister(dbTotalSize)
+	prometheus.MustRegister(dbTotalSizeDebug)
+	prometheus.MustRegister(dbTotalSizeInUse)
+	prometheus.MustRegister(dbOpenReadTxN)
+	prometheus.MustRegister(hashSec)
+	prometheus.MustRegister(hashRevSec)
+	prometheus.MustRegister(currentRev)
+	prometheus.MustRegister(compactRev)
+}
+
+// ReportEventReceived reports that an event is received.
+// This function should be called when the external systems received an
+// event from mvcc.Watcher.
+func ReportEventReceived(n int) {
+	pendingEventsGauge.Sub(float64(n))
+	totalEventsCounter.Add(float64(n))
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/metrics_txn.go b/vendor/go.etcd.io/etcd/mvcc/metrics_txn.go
new file mode 100644
index 0000000..64b629c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/metrics_txn.go
@@ -0,0 +1,67 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import "go.etcd.io/etcd/lease"
+
+type metricsTxnWrite struct {
+	TxnWrite
+	ranges  uint
+	puts    uint
+	deletes uint
+}
+
+func newMetricsTxnRead(tr TxnRead) TxnRead {
+	return &metricsTxnWrite{&txnReadWrite{tr}, 0, 0, 0}
+}
+
+func newMetricsTxnWrite(tw TxnWrite) TxnWrite {
+	return &metricsTxnWrite{tw, 0, 0, 0}
+}
+
+func (tw *metricsTxnWrite) Range(key, end []byte, ro RangeOptions) (*RangeResult, error) {
+	tw.ranges++
+	return tw.TxnWrite.Range(key, end, ro)
+}
+
+func (tw *metricsTxnWrite) DeleteRange(key, end []byte) (n, rev int64) {
+	tw.deletes++
+	return tw.TxnWrite.DeleteRange(key, end)
+}
+
+func (tw *metricsTxnWrite) Put(key, value []byte, lease lease.LeaseID) (rev int64) {
+	tw.puts++
+	return tw.TxnWrite.Put(key, value, lease)
+}
+
+func (tw *metricsTxnWrite) End() {
+	defer tw.TxnWrite.End()
+	if sum := tw.ranges + tw.puts + tw.deletes; sum > 1 {
+		txnCounter.Inc()
+		txnCounterDebug.Inc() // TODO: remove in 3.5 release
+	}
+
+	ranges := float64(tw.ranges)
+	rangeCounter.Add(ranges)
+	rangeCounterDebug.Add(ranges) // TODO: remove in 3.5 release
+
+	puts := float64(tw.puts)
+	putCounter.Add(puts)
+	putCounterDebug.Add(puts) // TODO: remove in 3.5 release
+
+	deletes := float64(tw.deletes)
+	deleteCounter.Add(deletes)
+	deleteCounterDebug.Add(deletes) // TODO: remove in 3.5 release
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/revision.go b/vendor/go.etcd.io/etcd/mvcc/revision.go
new file mode 100644
index 0000000..d621386
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/revision.go
@@ -0,0 +1,67 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import "encoding/binary"
+
+// revBytesLen is the byte length of a normal revision.
+// First 8 bytes is the revision.main in big-endian format. The 9th byte
+// is a '_'. The last 8 bytes is the revision.sub in big-endian format.
+const revBytesLen = 8 + 1 + 8
+
+// A revision indicates modification of the key-value space.
+// The set of changes that share same main revision changes the key-value space atomically.
+type revision struct {
+	// main is the main revision of a set of changes that happen atomically.
+	main int64
+
+	// sub is the sub revision of a change in a set of changes that happen
+	// atomically. Each change has different increasing sub revision in that
+	// set.
+	sub int64
+}
+
+func (a revision) GreaterThan(b revision) bool {
+	if a.main > b.main {
+		return true
+	}
+	if a.main < b.main {
+		return false
+	}
+	return a.sub > b.sub
+}
+
+func newRevBytes() []byte {
+	return make([]byte, revBytesLen, markedRevBytesLen)
+}
+
+func revToBytes(rev revision, bytes []byte) {
+	binary.BigEndian.PutUint64(bytes, uint64(rev.main))
+	bytes[8] = '_'
+	binary.BigEndian.PutUint64(bytes[9:], uint64(rev.sub))
+}
+
+func bytesToRev(bytes []byte) revision {
+	return revision{
+		main: int64(binary.BigEndian.Uint64(bytes[0:8])),
+		sub:  int64(binary.BigEndian.Uint64(bytes[9:])),
+	}
+}
+
+type revisions []revision
+
+func (a revisions) Len() int           { return len(a) }
+func (a revisions) Less(i, j int) bool { return a[j].GreaterThan(a[i]) }
+func (a revisions) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
diff --git a/vendor/go.etcd.io/etcd/mvcc/util.go b/vendor/go.etcd.io/etcd/mvcc/util.go
new file mode 100644
index 0000000..032621a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/util.go
@@ -0,0 +1,57 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+)
+
+func UpdateConsistentIndex(be backend.Backend, index uint64) {
+	tx := be.BatchTx()
+	tx.Lock()
+	defer tx.Unlock()
+
+	var oldi uint64
+	_, vs := tx.UnsafeRange(metaBucketName, consistentIndexKeyName, nil, 0)
+	if len(vs) != 0 {
+		oldi = binary.BigEndian.Uint64(vs[0])
+	}
+
+	if index <= oldi {
+		return
+	}
+
+	bs := make([]byte, 8)
+	binary.BigEndian.PutUint64(bs, index)
+	tx.UnsafePut(metaBucketName, consistentIndexKeyName, bs)
+}
+
+func WriteKV(be backend.Backend, kv mvccpb.KeyValue) {
+	ibytes := newRevBytes()
+	revToBytes(revision{main: kv.ModRevision}, ibytes)
+
+	d, err := kv.Marshal()
+	if err != nil {
+		panic(fmt.Errorf("cannot marshal event: %v", err))
+	}
+
+	be.BatchTx().Lock()
+	be.BatchTx().UnsafePut(keyBucketName, ibytes, d)
+	be.BatchTx().Unlock()
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/watchable_store.go b/vendor/go.etcd.io/etcd/mvcc/watchable_store.go
new file mode 100644
index 0000000..3cf491d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/watchable_store.go
@@ -0,0 +1,552 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc/backend"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.uber.org/zap"
+)
+
+// non-const so modifiable by tests
+var (
+	// chanBufLen is the length of the buffered chan
+	// for sending out watched events.
+	// TODO: find a good buf value. 1024 is just a random one that
+	// seems to be reasonable.
+	chanBufLen = 1024
+
+	// maxWatchersPerSync is the number of watchers to sync in a single batch
+	maxWatchersPerSync = 512
+)
+
+type watchable interface {
+	watch(key, end []byte, startRev int64, id WatchID, ch chan<- WatchResponse, fcs ...FilterFunc) (*watcher, cancelFunc)
+	progress(w *watcher)
+	rev() int64
+}
+
+type watchableStore struct {
+	*store
+
+	// mu protects watcher groups and batches. It should never be locked
+	// before locking store.mu to avoid deadlock.
+	mu sync.RWMutex
+
+	// victims are watcher batches that were blocked on the watch channel
+	victims []watcherBatch
+	victimc chan struct{}
+
+	// contains all unsynced watchers that needs to sync with events that have happened
+	unsynced watcherGroup
+
+	// contains all synced watchers that are in sync with the progress of the store.
+	// The key of the map is the key that the watcher watches on.
+	synced watcherGroup
+
+	stopc chan struct{}
+	wg    sync.WaitGroup
+}
+
+// cancelFunc updates unsynced and synced maps when running
+// cancel operations.
+type cancelFunc func()
+
+func New(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) ConsistentWatchableKV {
+	return newWatchableStore(lg, b, le, ig, cfg)
+}
+
+func newWatchableStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) *watchableStore {
+	s := &watchableStore{
+		store:    NewStore(lg, b, le, ig, cfg),
+		victimc:  make(chan struct{}, 1),
+		unsynced: newWatcherGroup(),
+		synced:   newWatcherGroup(),
+		stopc:    make(chan struct{}),
+	}
+	s.store.ReadView = &readView{s}
+	s.store.WriteView = &writeView{s}
+	if s.le != nil {
+		// use this store as the deleter so revokes trigger watch events
+		s.le.SetRangeDeleter(func() lease.TxnDelete { return s.Write() })
+	}
+	s.wg.Add(2)
+	go s.syncWatchersLoop()
+	go s.syncVictimsLoop()
+	return s
+}
+
+func (s *watchableStore) Close() error {
+	close(s.stopc)
+	s.wg.Wait()
+	return s.store.Close()
+}
+
+func (s *watchableStore) NewWatchStream() WatchStream {
+	watchStreamGauge.Inc()
+	return &watchStream{
+		watchable: s,
+		ch:        make(chan WatchResponse, chanBufLen),
+		cancels:   make(map[WatchID]cancelFunc),
+		watchers:  make(map[WatchID]*watcher),
+	}
+}
+
+func (s *watchableStore) watch(key, end []byte, startRev int64, id WatchID, ch chan<- WatchResponse, fcs ...FilterFunc) (*watcher, cancelFunc) {
+	wa := &watcher{
+		key:    key,
+		end:    end,
+		minRev: startRev,
+		id:     id,
+		ch:     ch,
+		fcs:    fcs,
+	}
+
+	s.mu.Lock()
+	s.revMu.RLock()
+	synced := startRev > s.store.currentRev || startRev == 0
+	if synced {
+		wa.minRev = s.store.currentRev + 1
+		if startRev > wa.minRev {
+			wa.minRev = startRev
+		}
+	}
+	if synced {
+		s.synced.add(wa)
+	} else {
+		slowWatcherGauge.Inc()
+		s.unsynced.add(wa)
+	}
+	s.revMu.RUnlock()
+	s.mu.Unlock()
+
+	watcherGauge.Inc()
+
+	return wa, func() { s.cancelWatcher(wa) }
+}
+
+// cancelWatcher removes references of the watcher from the watchableStore
+func (s *watchableStore) cancelWatcher(wa *watcher) {
+	for {
+		s.mu.Lock()
+		if s.unsynced.delete(wa) {
+			slowWatcherGauge.Dec()
+			break
+		} else if s.synced.delete(wa) {
+			break
+		} else if wa.compacted {
+			break
+		} else if wa.ch == nil {
+			// already canceled (e.g., cancel/close race)
+			break
+		}
+
+		if !wa.victim {
+			panic("watcher not victim but not in watch groups")
+		}
+
+		var victimBatch watcherBatch
+		for _, wb := range s.victims {
+			if wb[wa] != nil {
+				victimBatch = wb
+				break
+			}
+		}
+		if victimBatch != nil {
+			slowWatcherGauge.Dec()
+			delete(victimBatch, wa)
+			break
+		}
+
+		// victim being processed so not accessible; retry
+		s.mu.Unlock()
+		time.Sleep(time.Millisecond)
+	}
+
+	watcherGauge.Dec()
+	wa.ch = nil
+	s.mu.Unlock()
+}
+
+func (s *watchableStore) Restore(b backend.Backend) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	err := s.store.Restore(b)
+	if err != nil {
+		return err
+	}
+
+	for wa := range s.synced.watchers {
+		wa.restore = true
+		s.unsynced.add(wa)
+	}
+	s.synced = newWatcherGroup()
+	return nil
+}
+
+// syncWatchersLoop syncs the watcher in the unsynced map every 100ms.
+func (s *watchableStore) syncWatchersLoop() {
+	defer s.wg.Done()
+
+	for {
+		s.mu.RLock()
+		st := time.Now()
+		lastUnsyncedWatchers := s.unsynced.size()
+		s.mu.RUnlock()
+
+		unsyncedWatchers := 0
+		if lastUnsyncedWatchers > 0 {
+			unsyncedWatchers = s.syncWatchers()
+		}
+		syncDuration := time.Since(st)
+
+		waitDuration := 100 * time.Millisecond
+		// more work pending?
+		if unsyncedWatchers != 0 && lastUnsyncedWatchers > unsyncedWatchers {
+			// be fair to other store operations by yielding time taken
+			waitDuration = syncDuration
+		}
+
+		select {
+		case <-time.After(waitDuration):
+		case <-s.stopc:
+			return
+		}
+	}
+}
+
+// syncVictimsLoop tries to write precomputed watcher responses to
+// watchers that had a blocked watcher channel
+func (s *watchableStore) syncVictimsLoop() {
+	defer s.wg.Done()
+
+	for {
+		for s.moveVictims() != 0 {
+			// try to update all victim watchers
+		}
+		s.mu.RLock()
+		isEmpty := len(s.victims) == 0
+		s.mu.RUnlock()
+
+		var tickc <-chan time.Time
+		if !isEmpty {
+			tickc = time.After(10 * time.Millisecond)
+		}
+
+		select {
+		case <-tickc:
+		case <-s.victimc:
+		case <-s.stopc:
+			return
+		}
+	}
+}
+
+// moveVictims tries to update watches with already pending event data
+func (s *watchableStore) moveVictims() (moved int) {
+	s.mu.Lock()
+	victims := s.victims
+	s.victims = nil
+	s.mu.Unlock()
+
+	var newVictim watcherBatch
+	for _, wb := range victims {
+		// try to send responses again
+		for w, eb := range wb {
+			// watcher has observed the store up to, but not including, w.minRev
+			rev := w.minRev - 1
+			if w.send(WatchResponse{WatchID: w.id, Events: eb.evs, Revision: rev}) {
+				pendingEventsGauge.Add(float64(len(eb.evs)))
+			} else {
+				if newVictim == nil {
+					newVictim = make(watcherBatch)
+				}
+				newVictim[w] = eb
+				continue
+			}
+			moved++
+		}
+
+		// assign completed victim watchers to unsync/sync
+		s.mu.Lock()
+		s.store.revMu.RLock()
+		curRev := s.store.currentRev
+		for w, eb := range wb {
+			if newVictim != nil && newVictim[w] != nil {
+				// couldn't send watch response; stays victim
+				continue
+			}
+			w.victim = false
+			if eb.moreRev != 0 {
+				w.minRev = eb.moreRev
+			}
+			if w.minRev <= curRev {
+				s.unsynced.add(w)
+			} else {
+				slowWatcherGauge.Dec()
+				s.synced.add(w)
+			}
+		}
+		s.store.revMu.RUnlock()
+		s.mu.Unlock()
+	}
+
+	if len(newVictim) > 0 {
+		s.mu.Lock()
+		s.victims = append(s.victims, newVictim)
+		s.mu.Unlock()
+	}
+
+	return moved
+}
+
+// syncWatchers syncs unsynced watchers by:
+//	1. choose a set of watchers from the unsynced watcher group
+//	2. iterate over the set to get the minimum revision and remove compacted watchers
+//	3. use minimum revision to get all key-value pairs and send those events to watchers
+//	4. remove synced watchers in set from unsynced group and move to synced group
+func (s *watchableStore) syncWatchers() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	if s.unsynced.size() == 0 {
+		return 0
+	}
+
+	s.store.revMu.RLock()
+	defer s.store.revMu.RUnlock()
+
+	// in order to find key-value pairs from unsynced watchers, we need to
+	// find min revision index, and these revisions can be used to
+	// query the backend store of key-value pairs
+	curRev := s.store.currentRev
+	compactionRev := s.store.compactMainRev
+
+	wg, minRev := s.unsynced.choose(maxWatchersPerSync, curRev, compactionRev)
+	minBytes, maxBytes := newRevBytes(), newRevBytes()
+	revToBytes(revision{main: minRev}, minBytes)
+	revToBytes(revision{main: curRev + 1}, maxBytes)
+
+	// UnsafeRange returns keys and values. And in boltdb, keys are revisions.
+	// values are actual key-value pairs in backend.
+	tx := s.store.b.ReadTx()
+	tx.RLock()
+	revs, vs := tx.UnsafeRange(keyBucketName, minBytes, maxBytes, 0)
+	var evs []mvccpb.Event
+	if s.store != nil && s.store.lg != nil {
+		evs = kvsToEvents(s.store.lg, wg, revs, vs)
+	} else {
+		// TODO: remove this in v3.5
+		evs = kvsToEvents(nil, wg, revs, vs)
+	}
+	tx.RUnlock()
+
+	var victims watcherBatch
+	wb := newWatcherBatch(wg, evs)
+	for w := range wg.watchers {
+		w.minRev = curRev + 1
+
+		eb, ok := wb[w]
+		if !ok {
+			// bring un-notified watcher to synced
+			s.synced.add(w)
+			s.unsynced.delete(w)
+			continue
+		}
+
+		if eb.moreRev != 0 {
+			w.minRev = eb.moreRev
+		}
+
+		if w.send(WatchResponse{WatchID: w.id, Events: eb.evs, Revision: curRev}) {
+			pendingEventsGauge.Add(float64(len(eb.evs)))
+		} else {
+			if victims == nil {
+				victims = make(watcherBatch)
+			}
+			w.victim = true
+		}
+
+		if w.victim {
+			victims[w] = eb
+		} else {
+			if eb.moreRev != 0 {
+				// stay unsynced; more to read
+				continue
+			}
+			s.synced.add(w)
+		}
+		s.unsynced.delete(w)
+	}
+	s.addVictim(victims)
+
+	vsz := 0
+	for _, v := range s.victims {
+		vsz += len(v)
+	}
+	slowWatcherGauge.Set(float64(s.unsynced.size() + vsz))
+
+	return s.unsynced.size()
+}
+
+// kvsToEvents gets all events for the watchers from all key-value pairs
+func kvsToEvents(lg *zap.Logger, wg *watcherGroup, revs, vals [][]byte) (evs []mvccpb.Event) {
+	for i, v := range vals {
+		var kv mvccpb.KeyValue
+		if err := kv.Unmarshal(v); err != nil {
+			if lg != nil {
+				lg.Panic("failed to unmarshal mvccpb.KeyValue", zap.Error(err))
+			} else {
+				plog.Panicf("cannot unmarshal event: %v", err)
+			}
+		}
+
+		if !wg.contains(string(kv.Key)) {
+			continue
+		}
+
+		ty := mvccpb.PUT
+		if isTombstone(revs[i]) {
+			ty = mvccpb.DELETE
+			// patch in mod revision so watchers won't skip
+			kv.ModRevision = bytesToRev(revs[i]).main
+		}
+		evs = append(evs, mvccpb.Event{Kv: &kv, Type: ty})
+	}
+	return evs
+}
+
+// notify notifies the fact that given event at the given rev just happened to
+// watchers that watch on the key of the event.
+func (s *watchableStore) notify(rev int64, evs []mvccpb.Event) {
+	var victim watcherBatch
+	for w, eb := range newWatcherBatch(&s.synced, evs) {
+		if eb.revs != 1 {
+			if s.store != nil && s.store.lg != nil {
+				s.store.lg.Panic(
+					"unexpected multiple revisions in watch notification",
+					zap.Int("number-of-revisions", eb.revs),
+				)
+			} else {
+				plog.Panicf("unexpected multiple revisions in notification")
+			}
+		}
+		if w.send(WatchResponse{WatchID: w.id, Events: eb.evs, Revision: rev}) {
+			pendingEventsGauge.Add(float64(len(eb.evs)))
+		} else {
+			// move slow watcher to victims
+			w.minRev = rev + 1
+			if victim == nil {
+				victim = make(watcherBatch)
+			}
+			w.victim = true
+			victim[w] = eb
+			s.synced.delete(w)
+			slowWatcherGauge.Inc()
+		}
+	}
+	s.addVictim(victim)
+}
+
+func (s *watchableStore) addVictim(victim watcherBatch) {
+	if victim == nil {
+		return
+	}
+	s.victims = append(s.victims, victim)
+	select {
+	case s.victimc <- struct{}{}:
+	default:
+	}
+}
+
+func (s *watchableStore) rev() int64 { return s.store.Rev() }
+
+func (s *watchableStore) progress(w *watcher) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if _, ok := s.synced.watchers[w]; ok {
+		w.send(WatchResponse{WatchID: w.id, Revision: s.rev()})
+		// If the ch is full, this watcher is receiving events.
+		// We do not need to send progress at all.
+	}
+}
+
+type watcher struct {
+	// the watcher key
+	key []byte
+	// end indicates the end of the range to watch.
+	// If end is set, the watcher is on a range.
+	end []byte
+
+	// victim is set when ch is blocked and undergoing victim processing
+	victim bool
+
+	// compacted is set when the watcher is removed because of compaction
+	compacted bool
+
+	// restore is true when the watcher is being restored from leader snapshot
+	// which means that this watcher has just been moved from "synced" to "unsynced"
+	// watcher group, possibly with a future revision when it was first added
+	// to the synced watcher
+	// "unsynced" watcher revision must always be <= current revision,
+	// except when the watcher were to be moved from "synced" watcher group
+	restore bool
+
+	// minRev is the minimum revision update the watcher will accept
+	minRev int64
+	id     WatchID
+
+	fcs []FilterFunc
+	// a chan to send out the watch response.
+	// The chan might be shared with other watchers.
+	ch chan<- WatchResponse
+}
+
+func (w *watcher) send(wr WatchResponse) bool {
+	progressEvent := len(wr.Events) == 0
+
+	if len(w.fcs) != 0 {
+		ne := make([]mvccpb.Event, 0, len(wr.Events))
+		for i := range wr.Events {
+			filtered := false
+			for _, filter := range w.fcs {
+				if filter(wr.Events[i]) {
+					filtered = true
+					break
+				}
+			}
+			if !filtered {
+				ne = append(ne, wr.Events[i])
+			}
+		}
+		wr.Events = ne
+	}
+
+	// if all events are filtered out, we should send nothing.
+	if !progressEvent && len(wr.Events) == 0 {
+		return true
+	}
+	select {
+	case w.ch <- wr:
+		return true
+	default:
+		return false
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go b/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go
new file mode 100644
index 0000000..3bcfa4d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/watchable_store_txn.go
@@ -0,0 +1,51 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import "go.etcd.io/etcd/mvcc/mvccpb"
+
+func (tw *watchableStoreTxnWrite) End() {
+	changes := tw.Changes()
+	if len(changes) == 0 {
+		tw.TxnWrite.End()
+		return
+	}
+
+	rev := tw.Rev() + 1
+	evs := make([]mvccpb.Event, len(changes))
+	for i, change := range changes {
+		evs[i].Kv = &changes[i]
+		if change.CreateRevision == 0 {
+			evs[i].Type = mvccpb.DELETE
+			evs[i].Kv.ModRevision = rev
+		} else {
+			evs[i].Type = mvccpb.PUT
+		}
+	}
+
+	// end write txn under watchable store lock so the updates are visible
+	// when asynchronous event posting checks the current store revision
+	tw.s.mu.Lock()
+	tw.s.notify(rev, evs)
+	tw.TxnWrite.End()
+	tw.s.mu.Unlock()
+}
+
+type watchableStoreTxnWrite struct {
+	TxnWrite
+	s *watchableStore
+}
+
+func (s *watchableStore) Write() TxnWrite { return &watchableStoreTxnWrite{s.store.Write(), s} }
diff --git a/vendor/go.etcd.io/etcd/mvcc/watcher.go b/vendor/go.etcd.io/etcd/mvcc/watcher.go
new file mode 100644
index 0000000..2846d62
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/watcher.go
@@ -0,0 +1,193 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"bytes"
+	"errors"
+	"sync"
+
+	"go.etcd.io/etcd/mvcc/mvccpb"
+)
+
+// AutoWatchID is the watcher ID passed in WatchStream.Watch when no
+// user-provided ID is available. If pass, an ID will automatically be assigned.
+const AutoWatchID WatchID = 0
+
+var (
+	ErrWatcherNotExist    = errors.New("mvcc: watcher does not exist")
+	ErrEmptyWatcherRange  = errors.New("mvcc: watcher range is empty")
+	ErrWatcherDuplicateID = errors.New("mvcc: duplicate watch ID provided on the WatchStream")
+)
+
+type WatchID int64
+
+// FilterFunc returns true if the given event should be filtered out.
+type FilterFunc func(e mvccpb.Event) bool
+
+type WatchStream interface {
+	// Watch creates a watcher. The watcher watches the events happening or
+	// happened on the given key or range [key, end) from the given startRev.
+	//
+	// The whole event history can be watched unless compacted.
+	// If "startRev" <=0, watch observes events after currentRev.
+	//
+	// The returned "id" is the ID of this watcher. It appears as WatchID
+	// in events that are sent to the created watcher through stream channel.
+	// The watch ID is used when it's not equal to AutoWatchID. Otherwise,
+	// an auto-generated watch ID is returned.
+	Watch(id WatchID, key, end []byte, startRev int64, fcs ...FilterFunc) (WatchID, error)
+
+	// Chan returns a chan. All watch response will be sent to the returned chan.
+	Chan() <-chan WatchResponse
+
+	// RequestProgress requests the progress of the watcher with given ID. The response
+	// will only be sent if the watcher is currently synced.
+	// The responses will be sent through the WatchRespone Chan attached
+	// with this stream to ensure correct ordering.
+	// The responses contains no events. The revision in the response is the progress
+	// of the watchers since the watcher is currently synced.
+	RequestProgress(id WatchID)
+
+	// Cancel cancels a watcher by giving its ID. If watcher does not exist, an error will be
+	// returned.
+	Cancel(id WatchID) error
+
+	// Close closes Chan and release all related resources.
+	Close()
+
+	// Rev returns the current revision of the KV the stream watches on.
+	Rev() int64
+}
+
+type WatchResponse struct {
+	// WatchID is the WatchID of the watcher this response sent to.
+	WatchID WatchID
+
+	// Events contains all the events that needs to send.
+	Events []mvccpb.Event
+
+	// Revision is the revision of the KV when the watchResponse is created.
+	// For a normal response, the revision should be the same as the last
+	// modified revision inside Events. For a delayed response to a unsynced
+	// watcher, the revision is greater than the last modified revision
+	// inside Events.
+	Revision int64
+
+	// CompactRevision is set when the watcher is cancelled due to compaction.
+	CompactRevision int64
+}
+
+// watchStream contains a collection of watchers that share
+// one streaming chan to send out watched events and other control events.
+type watchStream struct {
+	watchable watchable
+	ch        chan WatchResponse
+
+	mu sync.Mutex // guards fields below it
+	// nextID is the ID pre-allocated for next new watcher in this stream
+	nextID   WatchID
+	closed   bool
+	cancels  map[WatchID]cancelFunc
+	watchers map[WatchID]*watcher
+}
+
+// Watch creates a new watcher in the stream and returns its WatchID.
+func (ws *watchStream) Watch(id WatchID, key, end []byte, startRev int64, fcs ...FilterFunc) (WatchID, error) {
+	// prevent wrong range where key >= end lexicographically
+	// watch request with 'WithFromKey' has empty-byte range end
+	if len(end) != 0 && bytes.Compare(key, end) != -1 {
+		return -1, ErrEmptyWatcherRange
+	}
+
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+	if ws.closed {
+		return -1, ErrEmptyWatcherRange
+	}
+
+	if id == AutoWatchID {
+		for ws.watchers[ws.nextID] != nil {
+			ws.nextID++
+		}
+		id = ws.nextID
+		ws.nextID++
+	} else if _, ok := ws.watchers[id]; ok {
+		return -1, ErrWatcherDuplicateID
+	}
+
+	w, c := ws.watchable.watch(key, end, startRev, id, ws.ch, fcs...)
+
+	ws.cancels[id] = c
+	ws.watchers[id] = w
+	return id, nil
+}
+
+func (ws *watchStream) Chan() <-chan WatchResponse {
+	return ws.ch
+}
+
+func (ws *watchStream) Cancel(id WatchID) error {
+	ws.mu.Lock()
+	cancel, ok := ws.cancels[id]
+	w := ws.watchers[id]
+	ok = ok && !ws.closed
+	ws.mu.Unlock()
+
+	if !ok {
+		return ErrWatcherNotExist
+	}
+	cancel()
+
+	ws.mu.Lock()
+	// The watch isn't removed until cancel so that if Close() is called,
+	// it will wait for the cancel. Otherwise, Close() could close the
+	// watch channel while the store is still posting events.
+	if ww := ws.watchers[id]; ww == w {
+		delete(ws.cancels, id)
+		delete(ws.watchers, id)
+	}
+	ws.mu.Unlock()
+
+	return nil
+}
+
+func (ws *watchStream) Close() {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+
+	for _, cancel := range ws.cancels {
+		cancel()
+	}
+	ws.closed = true
+	close(ws.ch)
+	watchStreamGauge.Dec()
+}
+
+func (ws *watchStream) Rev() int64 {
+	ws.mu.Lock()
+	defer ws.mu.Unlock()
+	return ws.watchable.rev()
+}
+
+func (ws *watchStream) RequestProgress(id WatchID) {
+	ws.mu.Lock()
+	w, ok := ws.watchers[id]
+	ws.mu.Unlock()
+	if !ok {
+		return
+	}
+	ws.watchable.progress(w)
+}
diff --git a/vendor/go.etcd.io/etcd/mvcc/watcher_group.go b/vendor/go.etcd.io/etcd/mvcc/watcher_group.go
new file mode 100644
index 0000000..151f0de
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/watcher_group.go
@@ -0,0 +1,293 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mvcc
+
+import (
+	"fmt"
+	"math"
+
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/pkg/adt"
+)
+
+var (
+	// watchBatchMaxRevs is the maximum distinct revisions that
+	// may be sent to an unsynced watcher at a time. Declared as
+	// var instead of const for testing purposes.
+	watchBatchMaxRevs = 1000
+)
+
+type eventBatch struct {
+	// evs is a batch of revision-ordered events
+	evs []mvccpb.Event
+	// revs is the minimum unique revisions observed for this batch
+	revs int
+	// moreRev is first revision with more events following this batch
+	moreRev int64
+}
+
+func (eb *eventBatch) add(ev mvccpb.Event) {
+	if eb.revs > watchBatchMaxRevs {
+		// maxed out batch size
+		return
+	}
+
+	if len(eb.evs) == 0 {
+		// base case
+		eb.revs = 1
+		eb.evs = append(eb.evs, ev)
+		return
+	}
+
+	// revision accounting
+	ebRev := eb.evs[len(eb.evs)-1].Kv.ModRevision
+	evRev := ev.Kv.ModRevision
+	if evRev > ebRev {
+		eb.revs++
+		if eb.revs > watchBatchMaxRevs {
+			eb.moreRev = evRev
+			return
+		}
+	}
+
+	eb.evs = append(eb.evs, ev)
+}
+
+type watcherBatch map[*watcher]*eventBatch
+
+func (wb watcherBatch) add(w *watcher, ev mvccpb.Event) {
+	eb := wb[w]
+	if eb == nil {
+		eb = &eventBatch{}
+		wb[w] = eb
+	}
+	eb.add(ev)
+}
+
+// newWatcherBatch maps watchers to their matched events. It enables quick
+// events look up by watcher.
+func newWatcherBatch(wg *watcherGroup, evs []mvccpb.Event) watcherBatch {
+	if len(wg.watchers) == 0 {
+		return nil
+	}
+
+	wb := make(watcherBatch)
+	for _, ev := range evs {
+		for w := range wg.watcherSetByKey(string(ev.Kv.Key)) {
+			if ev.Kv.ModRevision >= w.minRev {
+				// don't double notify
+				wb.add(w, ev)
+			}
+		}
+	}
+	return wb
+}
+
+type watcherSet map[*watcher]struct{}
+
+func (w watcherSet) add(wa *watcher) {
+	if _, ok := w[wa]; ok {
+		panic("add watcher twice!")
+	}
+	w[wa] = struct{}{}
+}
+
+func (w watcherSet) union(ws watcherSet) {
+	for wa := range ws {
+		w.add(wa)
+	}
+}
+
+func (w watcherSet) delete(wa *watcher) {
+	if _, ok := w[wa]; !ok {
+		panic("removing missing watcher!")
+	}
+	delete(w, wa)
+}
+
+type watcherSetByKey map[string]watcherSet
+
+func (w watcherSetByKey) add(wa *watcher) {
+	set := w[string(wa.key)]
+	if set == nil {
+		set = make(watcherSet)
+		w[string(wa.key)] = set
+	}
+	set.add(wa)
+}
+
+func (w watcherSetByKey) delete(wa *watcher) bool {
+	k := string(wa.key)
+	if v, ok := w[k]; ok {
+		if _, ok := v[wa]; ok {
+			delete(v, wa)
+			if len(v) == 0 {
+				// remove the set; nothing left
+				delete(w, k)
+			}
+			return true
+		}
+	}
+	return false
+}
+
+// watcherGroup is a collection of watchers organized by their ranges
+type watcherGroup struct {
+	// keyWatchers has the watchers that watch on a single key
+	keyWatchers watcherSetByKey
+	// ranges has the watchers that watch a range; it is sorted by interval
+	ranges adt.IntervalTree
+	// watchers is the set of all watchers
+	watchers watcherSet
+}
+
+func newWatcherGroup() watcherGroup {
+	return watcherGroup{
+		keyWatchers: make(watcherSetByKey),
+		ranges:      adt.NewIntervalTree(),
+		watchers:    make(watcherSet),
+	}
+}
+
+// add puts a watcher in the group.
+func (wg *watcherGroup) add(wa *watcher) {
+	wg.watchers.add(wa)
+	if wa.end == nil {
+		wg.keyWatchers.add(wa)
+		return
+	}
+
+	// interval already registered?
+	ivl := adt.NewStringAffineInterval(string(wa.key), string(wa.end))
+	if iv := wg.ranges.Find(ivl); iv != nil {
+		iv.Val.(watcherSet).add(wa)
+		return
+	}
+
+	// not registered, put in interval tree
+	ws := make(watcherSet)
+	ws.add(wa)
+	wg.ranges.Insert(ivl, ws)
+}
+
+// contains is whether the given key has a watcher in the group.
+func (wg *watcherGroup) contains(key string) bool {
+	_, ok := wg.keyWatchers[key]
+	return ok || wg.ranges.Intersects(adt.NewStringAffinePoint(key))
+}
+
+// size gives the number of unique watchers in the group.
+func (wg *watcherGroup) size() int { return len(wg.watchers) }
+
+// delete removes a watcher from the group.
+func (wg *watcherGroup) delete(wa *watcher) bool {
+	if _, ok := wg.watchers[wa]; !ok {
+		return false
+	}
+	wg.watchers.delete(wa)
+	if wa.end == nil {
+		wg.keyWatchers.delete(wa)
+		return true
+	}
+
+	ivl := adt.NewStringAffineInterval(string(wa.key), string(wa.end))
+	iv := wg.ranges.Find(ivl)
+	if iv == nil {
+		return false
+	}
+
+	ws := iv.Val.(watcherSet)
+	delete(ws, wa)
+	if len(ws) == 0 {
+		// remove interval missing watchers
+		if ok := wg.ranges.Delete(ivl); !ok {
+			panic("could not remove watcher from interval tree")
+		}
+	}
+
+	return true
+}
+
+// choose selects watchers from the watcher group to update
+func (wg *watcherGroup) choose(maxWatchers int, curRev, compactRev int64) (*watcherGroup, int64) {
+	if len(wg.watchers) < maxWatchers {
+		return wg, wg.chooseAll(curRev, compactRev)
+	}
+	ret := newWatcherGroup()
+	for w := range wg.watchers {
+		if maxWatchers <= 0 {
+			break
+		}
+		maxWatchers--
+		ret.add(w)
+	}
+	return &ret, ret.chooseAll(curRev, compactRev)
+}
+
+func (wg *watcherGroup) chooseAll(curRev, compactRev int64) int64 {
+	minRev := int64(math.MaxInt64)
+	for w := range wg.watchers {
+		if w.minRev > curRev {
+			// after network partition, possibly choosing future revision watcher from restore operation
+			// with watch key "proxy-namespace__lostleader" and revision "math.MaxInt64 - 2"
+			// do not panic when such watcher had been moved from "synced" watcher during restore operation
+			if !w.restore {
+				panic(fmt.Errorf("watcher minimum revision %d should not exceed current revision %d", w.minRev, curRev))
+			}
+
+			// mark 'restore' done, since it's chosen
+			w.restore = false
+		}
+		if w.minRev < compactRev {
+			select {
+			case w.ch <- WatchResponse{WatchID: w.id, CompactRevision: compactRev}:
+				w.compacted = true
+				wg.delete(w)
+			default:
+				// retry next time
+			}
+			continue
+		}
+		if minRev > w.minRev {
+			minRev = w.minRev
+		}
+	}
+	return minRev
+}
+
+// watcherSetByKey gets the set of watchers that receive events on the given key.
+func (wg *watcherGroup) watcherSetByKey(key string) watcherSet {
+	wkeys := wg.keyWatchers[key]
+	wranges := wg.ranges.Stab(adt.NewStringAffinePoint(key))
+
+	// zero-copy cases
+	switch {
+	case len(wranges) == 0:
+		// no need to merge ranges or copy; reuse single-key set
+		return wkeys
+	case len(wranges) == 0 && len(wkeys) == 0:
+		return nil
+	case len(wranges) == 1 && len(wkeys) == 0:
+		return wranges[0].Val.(watcherSet)
+	}
+
+	// copy case
+	ret := make(watcherSet)
+	ret.union(wg.keyWatchers[key])
+	for _, item := range wranges {
+		ret.union(item.Val.(watcherSet))
+	}
+	return ret
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/adt/README.md b/vendor/go.etcd.io/etcd/pkg/adt/README.md
new file mode 100644
index 0000000..a2089cd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/adt/README.md
@@ -0,0 +1,48 @@
+
+## Red-Black Tree
+
+*"Introduction to Algorithms" (Cormen et al, 3rd ed.), Chapter 13*
+
+1. Every node is either red or black.
+2. The root is black.
+3. Every leaf (NIL) is black.
+4. If a node is red, then both its children are black.
+5. For each node, all simple paths from the node to descendant leaves contain the
+same number of black nodes.
+
+For example,
+
+```go
+import (
+    "fmt"
+
+    "go.etcd.io/etcd/pkg/adt"
+)
+
+func main() {
+    ivt := adt.NewIntervalTree()
+    ivt.Insert(NewInt64Interval(510, 511), 0)
+    ivt.Insert(NewInt64Interval(82, 83), 0)
+    ivt.Insert(NewInt64Interval(830, 831), 0)
+    ...
+```
+
+After inserting the values `510`, `82`, `830`, `11`, `383`, `647`, `899`, `261`, `410`, `514`, `815`, `888`, `972`, `238`, `292`, `953`.
+
+![red-black-tree-01-insertion.png](img/red-black-tree-01-insertion.png)
+
+Deleting the node `514` should not trigger any rebalancing:
+
+![red-black-tree-02-delete-514.png](img/red-black-tree-02-delete-514.png)
+
+Deleting the node `11` triggers multiple rotates for rebalancing:
+
+![red-black-tree-03-delete-11.png](img/red-black-tree-03-delete-11.png)
+![red-black-tree-04-delete-11.png](img/red-black-tree-04-delete-11.png)
+![red-black-tree-05-delete-11.png](img/red-black-tree-05-delete-11.png)
+![red-black-tree-06-delete-11.png](img/red-black-tree-06-delete-11.png)
+![red-black-tree-07-delete-11.png](img/red-black-tree-07-delete-11.png)
+![red-black-tree-08-delete-11.png](img/red-black-tree-08-delete-11.png)
+![red-black-tree-09-delete-11.png](img/red-black-tree-09-delete-11.png)
+
+Try yourself at https://www.cs.usfca.edu/~galles/visualization/RedBlack.html.
diff --git a/vendor/go.etcd.io/etcd/pkg/adt/doc.go b/vendor/go.etcd.io/etcd/pkg/adt/doc.go
new file mode 100644
index 0000000..1a95591
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/adt/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package adt implements useful abstract data types.
+package adt
diff --git a/vendor/go.etcd.io/etcd/pkg/adt/interval_tree.go b/vendor/go.etcd.io/etcd/pkg/adt/interval_tree.go
new file mode 100644
index 0000000..2e5b2dd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/adt/interval_tree.go
@@ -0,0 +1,951 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adt
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"strings"
+)
+
+// Comparable is an interface for trichotomic comparisons.
+type Comparable interface {
+	// Compare gives the result of a 3-way comparison
+	// a.Compare(b) = 1 => a > b
+	// a.Compare(b) = 0 => a == b
+	// a.Compare(b) = -1 => a < b
+	Compare(c Comparable) int
+}
+
+type rbcolor int
+
+const (
+	black rbcolor = iota
+	red
+)
+
+func (c rbcolor) String() string {
+	switch c {
+	case black:
+		return "black"
+	case red:
+		return "black"
+	default:
+		panic(fmt.Errorf("unknown color %d", c))
+	}
+}
+
+// Interval implements a Comparable interval [begin, end)
+// TODO: support different sorts of intervals: (a,b), [a,b], (a, b]
+type Interval struct {
+	Begin Comparable
+	End   Comparable
+}
+
+// Compare on an interval gives == if the interval overlaps.
+func (ivl *Interval) Compare(c Comparable) int {
+	ivl2 := c.(*Interval)
+	ivbCmpBegin := ivl.Begin.Compare(ivl2.Begin)
+	ivbCmpEnd := ivl.Begin.Compare(ivl2.End)
+	iveCmpBegin := ivl.End.Compare(ivl2.Begin)
+
+	// ivl is left of ivl2
+	if ivbCmpBegin < 0 && iveCmpBegin <= 0 {
+		return -1
+	}
+
+	// iv is right of iv2
+	if ivbCmpEnd >= 0 {
+		return 1
+	}
+
+	return 0
+}
+
+type intervalNode struct {
+	// iv is the interval-value pair entry.
+	iv IntervalValue
+	// max endpoint of all descendent nodes.
+	max Comparable
+	// left and right are sorted by low endpoint of key interval
+	left, right *intervalNode
+	// parent is the direct ancestor of the node
+	parent *intervalNode
+	c      rbcolor
+}
+
+func (x *intervalNode) color(sentinel *intervalNode) rbcolor {
+	if x == sentinel {
+		return black
+	}
+	return x.c
+}
+
+func (x *intervalNode) height(sentinel *intervalNode) int {
+	if x == sentinel {
+		return 0
+	}
+	ld := x.left.height(sentinel)
+	rd := x.right.height(sentinel)
+	if ld < rd {
+		return rd + 1
+	}
+	return ld + 1
+}
+
+func (x *intervalNode) min(sentinel *intervalNode) *intervalNode {
+	for x.left != sentinel {
+		x = x.left
+	}
+	return x
+}
+
+// successor is the next in-order node in the tree
+func (x *intervalNode) successor(sentinel *intervalNode) *intervalNode {
+	if x.right != sentinel {
+		return x.right.min(sentinel)
+	}
+	y := x.parent
+	for y != sentinel && x == y.right {
+		x = y
+		y = y.parent
+	}
+	return y
+}
+
+// updateMax updates the maximum values for a node and its ancestors
+func (x *intervalNode) updateMax(sentinel *intervalNode) {
+	for x != sentinel {
+		oldmax := x.max
+		max := x.iv.Ivl.End
+		if x.left != sentinel && x.left.max.Compare(max) > 0 {
+			max = x.left.max
+		}
+		if x.right != sentinel && x.right.max.Compare(max) > 0 {
+			max = x.right.max
+		}
+		if oldmax.Compare(max) == 0 {
+			break
+		}
+		x.max = max
+		x = x.parent
+	}
+}
+
+type nodeVisitor func(n *intervalNode) bool
+
+// visit will call a node visitor on each node that overlaps the given interval
+func (x *intervalNode) visit(iv *Interval, sentinel *intervalNode, nv nodeVisitor) bool {
+	if x == sentinel {
+		return true
+	}
+	v := iv.Compare(&x.iv.Ivl)
+	switch {
+	case v < 0:
+		if !x.left.visit(iv, sentinel, nv) {
+			return false
+		}
+	case v > 0:
+		maxiv := Interval{x.iv.Ivl.Begin, x.max}
+		if maxiv.Compare(iv) == 0 {
+			if !x.left.visit(iv, sentinel, nv) || !x.right.visit(iv, sentinel, nv) {
+				return false
+			}
+		}
+	default:
+		if !x.left.visit(iv, sentinel, nv) || !nv(x) || !x.right.visit(iv, sentinel, nv) {
+			return false
+		}
+	}
+	return true
+}
+
+// IntervalValue represents a range tree node that contains a range and a value.
+type IntervalValue struct {
+	Ivl Interval
+	Val interface{}
+}
+
+// IntervalTree represents a (mostly) textbook implementation of the
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.) chapter 13 red-black tree
+// and chapter 14.3 interval tree with search supporting "stabbing queries".
+type IntervalTree interface {
+	// Insert adds a node with the given interval into the tree.
+	Insert(ivl Interval, val interface{})
+	// Delete removes the node with the given interval from the tree, returning
+	// true if a node is in fact removed.
+	Delete(ivl Interval) bool
+	// Len gives the number of elements in the tree.
+	Len() int
+	// Height is the number of levels in the tree; one node has height 1.
+	Height() int
+	// MaxHeight is the expected maximum tree height given the number of nodes.
+	MaxHeight() int
+	// Visit calls a visitor function on every tree node intersecting the given interval.
+	// It will visit each interval [x, y) in ascending order sorted on x.
+	Visit(ivl Interval, ivv IntervalVisitor)
+	// Find gets the IntervalValue for the node matching the given interval
+	Find(ivl Interval) *IntervalValue
+	// Intersects returns true if there is some tree node intersecting the given interval.
+	Intersects(iv Interval) bool
+	// Contains returns true if the interval tree's keys cover the entire given interval.
+	Contains(ivl Interval) bool
+	// Stab returns a slice with all elements in the tree intersecting the interval.
+	Stab(iv Interval) []*IntervalValue
+	// Union merges a given interval tree into the receiver.
+	Union(inIvt IntervalTree, ivl Interval)
+}
+
+// NewIntervalTree returns a new interval tree.
+func NewIntervalTree() IntervalTree {
+	sentinel := &intervalNode{
+		iv:     IntervalValue{},
+		max:    nil,
+		left:   nil,
+		right:  nil,
+		parent: nil,
+		c:      black,
+	}
+	return &intervalTree{
+		root:     sentinel,
+		count:    0,
+		sentinel: sentinel,
+	}
+}
+
+type intervalTree struct {
+	root  *intervalNode
+	count int
+
+	// red-black NIL node
+	// use 'sentinel' as a dummy object to simplify boundary conditions
+	// use the sentinel to treat a nil child of a node x as an ordinary node whose parent is x
+	// use one shared sentinel to represent all nil leaves and the root's parent
+	sentinel *intervalNode
+}
+
+// TODO: make this consistent with textbook implementation
+//
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.), chapter 13.4, p324
+//
+//	 0. RB-DELETE(T, z)
+//	 1.
+//	 2. y = z
+//	 3. y-original-color = y.color
+//	 4.
+//	 5. if z.left == T.nil
+//	 6. 	x = z.right
+//	 7. 	RB-TRANSPLANT(T, z, z.right)
+//	 8. else if z.right == T.nil
+//	 9. 	x = z.left
+//	10. 	RB-TRANSPLANT(T, z, z.left)
+//	11. else
+//	12. 	y = TREE-MINIMUM(z.right)
+//	13. 	y-original-color = y.color
+//	14. 	x = y.right
+//	15. 	if y.p == z
+//	16. 		x.p = y
+//	17. 	else
+//	18. 		RB-TRANSPLANT(T, y, y.right)
+//	19. 		y.right = z.right
+//	20. 		y.right.p = y
+//	21. 	RB-TRANSPLANT(T, z, y)
+//	22. 	y.left = z.left
+//	23. 	y.left.p = y
+//	24. 	y.color = z.color
+//	25.
+//	26. if y-original-color == BLACK
+//	27. 	RB-DELETE-FIXUP(T, x)
+
+// Delete removes the node with the given interval from the tree, returning
+// true if a node is in fact removed.
+func (ivt *intervalTree) Delete(ivl Interval) bool {
+	z := ivt.find(ivl)
+	if z == ivt.sentinel {
+		return false
+	}
+
+	y := z
+	if z.left != ivt.sentinel && z.right != ivt.sentinel {
+		y = z.successor(ivt.sentinel)
+	}
+
+	x := ivt.sentinel
+	if y.left != ivt.sentinel {
+		x = y.left
+	} else if y.right != ivt.sentinel {
+		x = y.right
+	}
+
+	x.parent = y.parent
+
+	if y.parent == ivt.sentinel {
+		ivt.root = x
+	} else {
+		if y == y.parent.left {
+			y.parent.left = x
+		} else {
+			y.parent.right = x
+		}
+		y.parent.updateMax(ivt.sentinel)
+	}
+	if y != z {
+		z.iv = y.iv
+		z.updateMax(ivt.sentinel)
+	}
+
+	if y.color(ivt.sentinel) == black {
+		ivt.deleteFixup(x)
+	}
+
+	ivt.count--
+	return true
+}
+
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.), chapter 13.4, p326
+//
+//	 0. RB-DELETE-FIXUP(T, z)
+//	 1.
+//	 2. while x ≠ T.root and x.color == BLACK
+//	 3. 	if x == x.p.left
+//	 4. 		w = x.p.right
+//	 5. 		if w.color == RED
+//	 6. 			w.color = BLACK
+//	 7. 			x.p.color = RED
+//	 8. 			LEFT-ROTATE(T, x, p)
+//	 9. 		if w.left.color == BLACK and w.right.color == BLACK
+//	10. 			w.color = RED
+//	11. 			x = x.p
+//	12. 		else if w.right.color == BLACK
+//	13. 				w.left.color = BLACK
+//	14. 				w.color = RED
+//	15. 				RIGHT-ROTATE(T, w)
+//	16. 				w = w.p.right
+//	17. 			w.color = x.p.color
+//	18. 			x.p.color = BLACK
+//	19. 			LEFT-ROTATE(T, w.p)
+//	20. 			x = T.root
+//	21. 	else
+//	22. 		w = x.p.left
+//	23. 		if w.color == RED
+//	24. 			w.color = BLACK
+//	25. 			x.p.color = RED
+//	26. 			RIGHT-ROTATE(T, x, p)
+//	27. 		if w.right.color == BLACK and w.left.color == BLACK
+//	28. 			w.color = RED
+//	29. 			x = x.p
+//	30. 		else if w.left.color == BLACK
+//	31. 				w.right.color = BLACK
+//	32. 				w.color = RED
+//	33. 				LEFT-ROTATE(T, w)
+//	34. 				w = w.p.left
+//	35. 			w.color = x.p.color
+//	36. 			x.p.color = BLACK
+//	37. 			RIGHT-ROTATE(T, w.p)
+//	38. 			x = T.root
+//	39.
+//	40. x.color = BLACK
+//
+func (ivt *intervalTree) deleteFixup(x *intervalNode) {
+	for x != ivt.root && x.color(ivt.sentinel) == black {
+		if x == x.parent.left { // line 3-20
+			w := x.parent.right
+			if w.color(ivt.sentinel) == red {
+				w.c = black
+				x.parent.c = red
+				ivt.rotateLeft(x.parent)
+				w = x.parent.right
+			}
+			if w == nil {
+				break
+			}
+			if w.left.color(ivt.sentinel) == black && w.right.color(ivt.sentinel) == black {
+				w.c = red
+				x = x.parent
+			} else {
+				if w.right.color(ivt.sentinel) == black {
+					w.left.c = black
+					w.c = red
+					ivt.rotateRight(w)
+					w = x.parent.right
+				}
+				w.c = x.parent.color(ivt.sentinel)
+				x.parent.c = black
+				w.right.c = black
+				ivt.rotateLeft(x.parent)
+				x = ivt.root
+			}
+		} else { // line 22-38
+			// same as above but with left and right exchanged
+			w := x.parent.left
+			if w.color(ivt.sentinel) == red {
+				w.c = black
+				x.parent.c = red
+				ivt.rotateRight(x.parent)
+				w = x.parent.left
+			}
+			if w == nil {
+				break
+			}
+			if w.left.color(ivt.sentinel) == black && w.right.color(ivt.sentinel) == black {
+				w.c = red
+				x = x.parent
+			} else {
+				if w.left.color(ivt.sentinel) == black {
+					w.right.c = black
+					w.c = red
+					ivt.rotateLeft(w)
+					w = x.parent.left
+				}
+				w.c = x.parent.color(ivt.sentinel)
+				x.parent.c = black
+				w.left.c = black
+				ivt.rotateRight(x.parent)
+				x = ivt.root
+			}
+		}
+	}
+
+	if x != nil {
+		x.c = black
+	}
+}
+
+func (ivt *intervalTree) createIntervalNode(ivl Interval, val interface{}) *intervalNode {
+	return &intervalNode{
+		iv:     IntervalValue{ivl, val},
+		max:    ivl.End,
+		c:      red,
+		left:   ivt.sentinel,
+		right:  ivt.sentinel,
+		parent: ivt.sentinel,
+	}
+}
+
+// TODO: make this consistent with textbook implementation
+//
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.), chapter 13.3, p315
+//
+//	 0. RB-INSERT(T, z)
+//	 1.
+//	 2. y = T.nil
+//	 3. x = T.root
+//	 4.
+//	 5. while x ≠ T.nil
+//	 6. 	y = x
+//	 7. 	if z.key < x.key
+//	 8. 		x = x.left
+//	 9. 	else
+//	10. 		x = x.right
+//	11.
+//	12. z.p = y
+//	13.
+//	14. if y == T.nil
+//	15. 	T.root = z
+//	16. else if z.key < y.key
+//	17. 	y.left = z
+//	18. else
+//	19. 	y.right = z
+//	20.
+//	21. z.left = T.nil
+//	22. z.right = T.nil
+//	23. z.color = RED
+//	24.
+//	25. RB-INSERT-FIXUP(T, z)
+
+// Insert adds a node with the given interval into the tree.
+func (ivt *intervalTree) Insert(ivl Interval, val interface{}) {
+	y := ivt.sentinel
+	z := ivt.createIntervalNode(ivl, val)
+	x := ivt.root
+	for x != ivt.sentinel {
+		y = x
+		if z.iv.Ivl.Begin.Compare(x.iv.Ivl.Begin) < 0 {
+			x = x.left
+		} else {
+			x = x.right
+		}
+	}
+
+	z.parent = y
+	if y == ivt.sentinel {
+		ivt.root = z
+	} else {
+		if z.iv.Ivl.Begin.Compare(y.iv.Ivl.Begin) < 0 {
+			y.left = z
+		} else {
+			y.right = z
+		}
+		y.updateMax(ivt.sentinel)
+	}
+	z.c = red
+
+	ivt.insertFixup(z)
+	ivt.count++
+}
+
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.), chapter 13.3, p316
+//
+//	 0. RB-INSERT-FIXUP(T, z)
+//	 1.
+//	 2. while z.p.color == RED
+//	 3. 	if z.p == z.p.p.left
+//	 4. 		y = z.p.p.right
+//	 5. 		if y.color == RED
+//	 6. 			z.p.color = BLACK
+//	 7. 			y.color = BLACK
+//	 8. 			z.p.p.color = RED
+//	 9. 			z = z.p.p
+//	10. 		else if z == z.p.right
+//	11. 				z = z.p
+//	12. 				LEFT-ROTATE(T, z)
+//	13. 			z.p.color = BLACK
+//	14. 			z.p.p.color = RED
+//	15. 			RIGHT-ROTATE(T, z.p.p)
+//	16. 	else
+//	17. 		y = z.p.p.left
+//	18. 		if y.color == RED
+//	19. 			z.p.color = BLACK
+//	20. 			y.color = BLACK
+//	21. 			z.p.p.color = RED
+//	22. 			z = z.p.p
+//	23. 		else if z == z.p.right
+//	24. 				z = z.p
+//	25. 				RIGHT-ROTATE(T, z)
+//	26. 			z.p.color = BLACK
+//	27. 			z.p.p.color = RED
+//	28. 			LEFT-ROTATE(T, z.p.p)
+//	29.
+//	30. T.root.color = BLACK
+//
+func (ivt *intervalTree) insertFixup(z *intervalNode) {
+	for z.parent.color(ivt.sentinel) == red {
+		if z.parent == z.parent.parent.left { // line 3-15
+
+			y := z.parent.parent.right
+			if y.color(ivt.sentinel) == red {
+				y.c = black
+				z.parent.c = black
+				z.parent.parent.c = red
+				z = z.parent.parent
+			} else {
+				if z == z.parent.right {
+					z = z.parent
+					ivt.rotateLeft(z)
+				}
+				z.parent.c = black
+				z.parent.parent.c = red
+				ivt.rotateRight(z.parent.parent)
+			}
+		} else { // line 16-28
+			// same as then with left/right exchanged
+			y := z.parent.parent.left
+			if y.color(ivt.sentinel) == red {
+				y.c = black
+				z.parent.c = black
+				z.parent.parent.c = red
+				z = z.parent.parent
+			} else {
+				if z == z.parent.left {
+					z = z.parent
+					ivt.rotateRight(z)
+				}
+				z.parent.c = black
+				z.parent.parent.c = red
+				ivt.rotateLeft(z.parent.parent)
+			}
+		}
+	}
+
+	// line 30
+	ivt.root.c = black
+}
+
+// rotateLeft moves x so it is left of its right child
+//
+// "Introduction to Algorithms" (Cormen et al, 3rd ed.), chapter 13.2, p313
+//
+//	 0. LEFT-ROTATE(T, x)
+//	 1.
+//	 2. y = x.right
+//	 3. x.right = y.left
+//	 4.
+//	 5. if y.left ≠ T.nil
+//	 6. 	y.left.p = x
+//	 7.
+//	 8. y.p = x.p
+//	 9.
+//	10. if x.p == T.nil
+//	11. 	T.root = y
+//	12. else if x == x.p.left
+//	13. 	x.p.left = y
+//	14. else
+//	15. 	x.p.right = y
+//	16.
+//	17. y.left = x
+//	18. x.p = y
+//
+func (ivt *intervalTree) rotateLeft(x *intervalNode) {
+	// rotateLeft x must have right child
+	if x.right == ivt.sentinel {
+		return
+	}
+
+	// line 2-3
+	y := x.right
+	x.right = y.left
+
+	// line 5-6
+	if y.left != ivt.sentinel {
+		y.left.parent = x
+	}
+	x.updateMax(ivt.sentinel)
+
+	// line 10-15, 18
+	ivt.replaceParent(x, y)
+
+	// line 17
+	y.left = x
+	y.updateMax(ivt.sentinel)
+}
+
+// rotateRight moves x so it is right of its left child
+//
+//	 0. RIGHT-ROTATE(T, x)
+//	 1.
+//	 2. y = x.left
+//	 3. x.left = y.right
+//	 4.
+//	 5. if y.right ≠ T.nil
+//	 6. 	y.right.p = x
+//	 7.
+//	 8. y.p = x.p
+//	 9.
+//	10. if x.p == T.nil
+//	11. 	T.root = y
+//	12. else if x == x.p.right
+//	13. 	x.p.right = y
+//	14. else
+//	15. 	x.p.left = y
+//	16.
+//	17. y.right = x
+//	18. x.p = y
+//
+func (ivt *intervalTree) rotateRight(x *intervalNode) {
+	// rotateRight x must have left child
+	if x.left == ivt.sentinel {
+		return
+	}
+
+	// line 2-3
+	y := x.left
+	x.left = y.right
+
+	// line 5-6
+	if y.right != ivt.sentinel {
+		y.right.parent = x
+	}
+	x.updateMax(ivt.sentinel)
+
+	// line 10-15, 18
+	ivt.replaceParent(x, y)
+
+	// line 17
+	y.right = x
+	y.updateMax(ivt.sentinel)
+}
+
+// replaceParent replaces x's parent with y
+func (ivt *intervalTree) replaceParent(x *intervalNode, y *intervalNode) {
+	y.parent = x.parent
+	if x.parent == ivt.sentinel {
+		ivt.root = y
+	} else {
+		if x == x.parent.left {
+			x.parent.left = y
+		} else {
+			x.parent.right = y
+		}
+		x.parent.updateMax(ivt.sentinel)
+	}
+	x.parent = y
+}
+
+// Len gives the number of elements in the tree
+func (ivt *intervalTree) Len() int { return ivt.count }
+
+// Height is the number of levels in the tree; one node has height 1.
+func (ivt *intervalTree) Height() int { return ivt.root.height(ivt.sentinel) }
+
+// MaxHeight is the expected maximum tree height given the number of nodes
+func (ivt *intervalTree) MaxHeight() int {
+	return int((2 * math.Log2(float64(ivt.Len()+1))) + 0.5)
+}
+
+// IntervalVisitor is used on tree searches; return false to stop searching.
+type IntervalVisitor func(n *IntervalValue) bool
+
+// Visit calls a visitor function on every tree node intersecting the given interval.
+// It will visit each interval [x, y) in ascending order sorted on x.
+func (ivt *intervalTree) Visit(ivl Interval, ivv IntervalVisitor) {
+	ivt.root.visit(&ivl, ivt.sentinel, func(n *intervalNode) bool { return ivv(&n.iv) })
+}
+
+// find the exact node for a given interval
+func (ivt *intervalTree) find(ivl Interval) *intervalNode {
+	ret := ivt.sentinel
+	f := func(n *intervalNode) bool {
+		if n.iv.Ivl != ivl {
+			return true
+		}
+		ret = n
+		return false
+	}
+	ivt.root.visit(&ivl, ivt.sentinel, f)
+	return ret
+}
+
+// Find gets the IntervalValue for the node matching the given interval
+func (ivt *intervalTree) Find(ivl Interval) (ret *IntervalValue) {
+	n := ivt.find(ivl)
+	if n == ivt.sentinel {
+		return nil
+	}
+	return &n.iv
+}
+
+// Intersects returns true if there is some tree node intersecting the given interval.
+func (ivt *intervalTree) Intersects(iv Interval) bool {
+	x := ivt.root
+	for x != ivt.sentinel && iv.Compare(&x.iv.Ivl) != 0 {
+		if x.left != ivt.sentinel && x.left.max.Compare(iv.Begin) > 0 {
+			x = x.left
+		} else {
+			x = x.right
+		}
+	}
+	return x != ivt.sentinel
+}
+
+// Contains returns true if the interval tree's keys cover the entire given interval.
+func (ivt *intervalTree) Contains(ivl Interval) bool {
+	var maxEnd, minBegin Comparable
+
+	isContiguous := true
+	ivt.Visit(ivl, func(n *IntervalValue) bool {
+		if minBegin == nil {
+			minBegin = n.Ivl.Begin
+			maxEnd = n.Ivl.End
+			return true
+		}
+		if maxEnd.Compare(n.Ivl.Begin) < 0 {
+			isContiguous = false
+			return false
+		}
+		if n.Ivl.End.Compare(maxEnd) > 0 {
+			maxEnd = n.Ivl.End
+		}
+		return true
+	})
+
+	return isContiguous && minBegin != nil && maxEnd.Compare(ivl.End) >= 0 && minBegin.Compare(ivl.Begin) <= 0
+}
+
+// Stab returns a slice with all elements in the tree intersecting the interval.
+func (ivt *intervalTree) Stab(iv Interval) (ivs []*IntervalValue) {
+	if ivt.count == 0 {
+		return nil
+	}
+	f := func(n *IntervalValue) bool { ivs = append(ivs, n); return true }
+	ivt.Visit(iv, f)
+	return ivs
+}
+
+// Union merges a given interval tree into the receiver.
+func (ivt *intervalTree) Union(inIvt IntervalTree, ivl Interval) {
+	f := func(n *IntervalValue) bool {
+		ivt.Insert(n.Ivl, n.Val)
+		return true
+	}
+	inIvt.Visit(ivl, f)
+}
+
+type visitedInterval struct {
+	root  Interval
+	left  Interval
+	right Interval
+	color rbcolor
+	depth int
+}
+
+func (vi visitedInterval) String() string {
+	bd := new(strings.Builder)
+	bd.WriteString(fmt.Sprintf("root [%v,%v,%v], left [%v,%v], right [%v,%v], depth %d",
+		vi.root.Begin, vi.root.End, vi.color,
+		vi.left.Begin, vi.left.End,
+		vi.right.Begin, vi.right.End,
+		vi.depth,
+	))
+	return bd.String()
+}
+
+// visitLevel traverses tree in level order.
+// used for testing
+func (ivt *intervalTree) visitLevel() []visitedInterval {
+	if ivt.root == ivt.sentinel {
+		return nil
+	}
+
+	rs := make([]visitedInterval, 0, ivt.Len())
+
+	type pair struct {
+		node  *intervalNode
+		depth int
+	}
+	queue := []pair{{ivt.root, 0}}
+	for len(queue) > 0 {
+		f := queue[0]
+		queue = queue[1:]
+
+		vi := visitedInterval{
+			root:  f.node.iv.Ivl,
+			color: f.node.color(ivt.sentinel),
+			depth: f.depth,
+		}
+		if f.node.left != ivt.sentinel {
+			vi.left = f.node.left.iv.Ivl
+			queue = append(queue, pair{f.node.left, f.depth + 1})
+		}
+		if f.node.right != ivt.sentinel {
+			vi.right = f.node.right.iv.Ivl
+			queue = append(queue, pair{f.node.right, f.depth + 1})
+		}
+
+		rs = append(rs, vi)
+	}
+
+	return rs
+}
+
+type StringComparable string
+
+func (s StringComparable) Compare(c Comparable) int {
+	sc := c.(StringComparable)
+	if s < sc {
+		return -1
+	}
+	if s > sc {
+		return 1
+	}
+	return 0
+}
+
+func NewStringInterval(begin, end string) Interval {
+	return Interval{StringComparable(begin), StringComparable(end)}
+}
+
+func NewStringPoint(s string) Interval {
+	return Interval{StringComparable(s), StringComparable(s + "\x00")}
+}
+
+// StringAffineComparable treats "" as > all other strings
+type StringAffineComparable string
+
+func (s StringAffineComparable) Compare(c Comparable) int {
+	sc := c.(StringAffineComparable)
+
+	if len(s) == 0 {
+		if len(sc) == 0 {
+			return 0
+		}
+		return 1
+	}
+	if len(sc) == 0 {
+		return -1
+	}
+
+	if s < sc {
+		return -1
+	}
+	if s > sc {
+		return 1
+	}
+	return 0
+}
+
+func NewStringAffineInterval(begin, end string) Interval {
+	return Interval{StringAffineComparable(begin), StringAffineComparable(end)}
+}
+
+func NewStringAffinePoint(s string) Interval {
+	return NewStringAffineInterval(s, s+"\x00")
+}
+
+func NewInt64Interval(a int64, b int64) Interval {
+	return Interval{Int64Comparable(a), Int64Comparable(b)}
+}
+
+func newInt64EmptyInterval() Interval {
+	return Interval{Begin: nil, End: nil}
+}
+
+func NewInt64Point(a int64) Interval {
+	return Interval{Int64Comparable(a), Int64Comparable(a + 1)}
+}
+
+type Int64Comparable int64
+
+func (v Int64Comparable) Compare(c Comparable) int {
+	vc := c.(Int64Comparable)
+	cmp := v - vc
+	if cmp < 0 {
+		return -1
+	}
+	if cmp > 0 {
+		return 1
+	}
+	return 0
+}
+
+// BytesAffineComparable treats empty byte arrays as > all other byte arrays
+type BytesAffineComparable []byte
+
+func (b BytesAffineComparable) Compare(c Comparable) int {
+	bc := c.(BytesAffineComparable)
+
+	if len(b) == 0 {
+		if len(bc) == 0 {
+			return 0
+		}
+		return 1
+	}
+	if len(bc) == 0 {
+		return -1
+	}
+
+	return bytes.Compare(b, bc)
+}
+
+func NewBytesAffineInterval(begin, end []byte) Interval {
+	return Interval{BytesAffineComparable(begin), BytesAffineComparable(end)}
+}
+
+func NewBytesAffinePoint(b []byte) Interval {
+	be := make([]byte, len(b)+1)
+	copy(be, b)
+	be[len(b)] = 0
+	return NewBytesAffineInterval(b, be)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/contention/contention.go b/vendor/go.etcd.io/etcd/pkg/contention/contention.go
new file mode 100644
index 0000000..26ce9a2
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/contention/contention.go
@@ -0,0 +1,69 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package contention
+
+import (
+	"sync"
+	"time"
+)
+
+// TimeoutDetector detects routine starvations by
+// observing the actual time duration to finish an action
+// or between two events that should happen in a fixed
+// interval. If the observed duration is longer than
+// the expectation, the detector will report the result.
+type TimeoutDetector struct {
+	mu          sync.Mutex // protects all
+	maxDuration time.Duration
+	// map from event to time
+	// time is the last seen time of the event.
+	records map[uint64]time.Time
+}
+
+// NewTimeoutDetector creates the TimeoutDetector.
+func NewTimeoutDetector(maxDuration time.Duration) *TimeoutDetector {
+	return &TimeoutDetector{
+		maxDuration: maxDuration,
+		records:     make(map[uint64]time.Time),
+	}
+}
+
+// Reset resets the NewTimeoutDetector.
+func (td *TimeoutDetector) Reset() {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+
+	td.records = make(map[uint64]time.Time)
+}
+
+// Observe observes an event for given id. It returns false and exceeded duration
+// if the interval is longer than the expectation.
+func (td *TimeoutDetector) Observe(which uint64) (bool, time.Duration) {
+	td.mu.Lock()
+	defer td.mu.Unlock()
+
+	ok := true
+	now := time.Now()
+	exceed := time.Duration(0)
+
+	if pt, found := td.records[which]; found {
+		exceed = now.Sub(pt) - td.maxDuration
+		if exceed > 0 {
+			ok = false
+		}
+	}
+	td.records[which] = now
+	return ok, exceed
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/contention/doc.go b/vendor/go.etcd.io/etcd/pkg/contention/doc.go
new file mode 100644
index 0000000..daf4522
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/contention/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package contention provides facilities for detecting system contention.
+package contention
diff --git a/vendor/go.etcd.io/etcd/pkg/cpuutil/doc.go b/vendor/go.etcd.io/etcd/pkg/cpuutil/doc.go
new file mode 100644
index 0000000..0323b2d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/cpuutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package cpuutil provides facilities for detecting cpu-specific features.
+package cpuutil
diff --git a/vendor/go.etcd.io/etcd/pkg/cpuutil/endian.go b/vendor/go.etcd.io/etcd/pkg/cpuutil/endian.go
new file mode 100644
index 0000000..06c06cd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/cpuutil/endian.go
@@ -0,0 +1,36 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cpuutil
+
+import (
+	"encoding/binary"
+	"unsafe"
+)
+
+const intWidth int = int(unsafe.Sizeof(0))
+
+var byteOrder binary.ByteOrder
+
+// ByteOrder returns the byte order for the CPU's native endianness.
+func ByteOrder() binary.ByteOrder { return byteOrder }
+
+func init() {
+	i := int(0x1)
+	if v := (*[intWidth]byte)(unsafe.Pointer(&i)); v[0] == 0 {
+		byteOrder = binary.BigEndian
+	} else {
+		byteOrder = binary.LittleEndian
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/crc/crc.go b/vendor/go.etcd.io/etcd/pkg/crc/crc.go
new file mode 100644
index 0000000..4b998a4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/crc/crc.go
@@ -0,0 +1,43 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package crc provides utility function for cyclic redundancy check
+// algorithms.
+package crc
+
+import (
+	"hash"
+	"hash/crc32"
+)
+
+// The size of a CRC-32 checksum in bytes.
+const Size = 4
+
+type digest struct {
+	crc uint32
+	tab *crc32.Table
+}
+
+// New creates a new hash.Hash32 computing the CRC-32 checksum
+// using the polynomial represented by the Table.
+// Modified by xiangli to take a prevcrc.
+func New(prev uint32, tab *crc32.Table) hash.Hash32 { return &digest{prev, tab} }
+
+func (d *digest) Size() int { return Size }
+
+func (d *digest) BlockSize() int { return 1 }
+
+func (d *digest) Reset() { d.crc = 0 }
+
+func (d *digest) Write(p []byte) (n int, err error) {
+	d.crc = crc32.Update(d.crc, d.tab, p)
+	return len(p), nil
+}
+
+func (d *digest) Sum32() uint32 { return d.crc }
+
+func (d *digest) Sum(in []byte) []byte {
+	s := d.Sum32()
+	return append(in, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/debugutil/doc.go b/vendor/go.etcd.io/etcd/pkg/debugutil/doc.go
new file mode 100644
index 0000000..74499eb
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/debugutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package debugutil includes utility functions for debugging.
+package debugutil
diff --git a/vendor/go.etcd.io/etcd/pkg/debugutil/pprof.go b/vendor/go.etcd.io/etcd/pkg/debugutil/pprof.go
new file mode 100644
index 0000000..8d5544a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/debugutil/pprof.go
@@ -0,0 +1,47 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package debugutil
+
+import (
+	"net/http"
+	"net/http/pprof"
+	"runtime"
+)
+
+const HTTPPrefixPProf = "/debug/pprof"
+
+// PProfHandlers returns a map of pprof handlers keyed by the HTTP path.
+func PProfHandlers() map[string]http.Handler {
+	// set only when there's no existing setting
+	if runtime.SetMutexProfileFraction(-1) == 0 {
+		// 1 out of 5 mutex events are reported, on average
+		runtime.SetMutexProfileFraction(5)
+	}
+
+	m := make(map[string]http.Handler)
+
+	m[HTTPPrefixPProf+"/"] = http.HandlerFunc(pprof.Index)
+	m[HTTPPrefixPProf+"/profile"] = http.HandlerFunc(pprof.Profile)
+	m[HTTPPrefixPProf+"/symbol"] = http.HandlerFunc(pprof.Symbol)
+	m[HTTPPrefixPProf+"/cmdline"] = http.HandlerFunc(pprof.Cmdline)
+	m[HTTPPrefixPProf+"/trace "] = http.HandlerFunc(pprof.Trace)
+	m[HTTPPrefixPProf+"/heap"] = pprof.Handler("heap")
+	m[HTTPPrefixPProf+"/goroutine"] = pprof.Handler("goroutine")
+	m[HTTPPrefixPProf+"/threadcreate"] = pprof.Handler("threadcreate")
+	m[HTTPPrefixPProf+"/block"] = pprof.Handler("block")
+	m[HTTPPrefixPProf+"/mutex"] = pprof.Handler("mutex")
+
+	return m
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/dir_unix.go b/vendor/go.etcd.io/etcd/pkg/fileutil/dir_unix.go
new file mode 100644
index 0000000..58a77df
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/dir_unix.go
@@ -0,0 +1,22 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows
+
+package fileutil
+
+import "os"
+
+// OpenDir opens a directory for syncing.
+func OpenDir(path string) (*os.File, error) { return os.Open(path) }
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/dir_windows.go b/vendor/go.etcd.io/etcd/pkg/fileutil/dir_windows.go
new file mode 100644
index 0000000..c123395
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/dir_windows.go
@@ -0,0 +1,46 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build windows
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// OpenDir opens a directory in windows with write access for syncing.
+func OpenDir(path string) (*os.File, error) {
+	fd, err := openDir(path)
+	if err != nil {
+		return nil, err
+	}
+	return os.NewFile(uintptr(fd), path), nil
+}
+
+func openDir(path string) (fd syscall.Handle, err error) {
+	if len(path) == 0 {
+		return syscall.InvalidHandle, syscall.ERROR_FILE_NOT_FOUND
+	}
+	pathp, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return syscall.InvalidHandle, err
+	}
+	access := uint32(syscall.GENERIC_READ | syscall.GENERIC_WRITE)
+	sharemode := uint32(syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE)
+	createmode := uint32(syscall.OPEN_EXISTING)
+	fl := uint32(syscall.FILE_FLAG_BACKUP_SEMANTICS)
+	return syscall.CreateFile(pathp, access, sharemode, nil, createmode, fl, 0)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/doc.go b/vendor/go.etcd.io/etcd/pkg/fileutil/doc.go
new file mode 100644
index 0000000..69dde5a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package fileutil implements utility functions related to files and paths.
+package fileutil
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go b/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go
new file mode 100644
index 0000000..5d9fb53
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/fileutil.go
@@ -0,0 +1,104 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/coreos/pkg/capnslog"
+)
+
+const (
+	// PrivateFileMode grants owner to read/write a file.
+	PrivateFileMode = 0600
+	// PrivateDirMode grants owner to make/remove files inside the directory.
+	PrivateDirMode = 0700
+)
+
+var plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "pkg/fileutil")
+
+// IsDirWriteable checks if dir is writable by writing and removing a file
+// to dir. It returns nil if dir is writable.
+func IsDirWriteable(dir string) error {
+	f := filepath.Join(dir, ".touch")
+	if err := ioutil.WriteFile(f, []byte(""), PrivateFileMode); err != nil {
+		return err
+	}
+	return os.Remove(f)
+}
+
+// TouchDirAll is similar to os.MkdirAll. It creates directories with 0700 permission if any directory
+// does not exists. TouchDirAll also ensures the given directory is writable.
+func TouchDirAll(dir string) error {
+	// If path is already a directory, MkdirAll does nothing
+	// and returns nil.
+	err := os.MkdirAll(dir, PrivateDirMode)
+	if err != nil {
+		// if mkdirAll("a/text") and "text" is not
+		// a directory, this will return syscall.ENOTDIR
+		return err
+	}
+	return IsDirWriteable(dir)
+}
+
+// CreateDirAll is similar to TouchDirAll but returns error
+// if the deepest directory was not empty.
+func CreateDirAll(dir string) error {
+	err := TouchDirAll(dir)
+	if err == nil {
+		var ns []string
+		ns, err = ReadDir(dir)
+		if err != nil {
+			return err
+		}
+		if len(ns) != 0 {
+			err = fmt.Errorf("expected %q to be empty, got %q", dir, ns)
+		}
+	}
+	return err
+}
+
+// Exist returns true if a file or directory exists.
+func Exist(name string) bool {
+	_, err := os.Stat(name)
+	return err == nil
+}
+
+// ZeroToEnd zeros a file starting from SEEK_CUR to its SEEK_END. May temporarily
+// shorten the length of the file.
+func ZeroToEnd(f *os.File) error {
+	// TODO: support FALLOC_FL_ZERO_RANGE
+	off, err := f.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return err
+	}
+	lenf, lerr := f.Seek(0, io.SeekEnd)
+	if lerr != nil {
+		return lerr
+	}
+	if err = f.Truncate(off); err != nil {
+		return err
+	}
+	// make sure blocks remain allocated
+	if err = Preallocate(f, lenf, true); err != nil {
+		return err
+	}
+	_, err = f.Seek(off, io.SeekStart)
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock.go
new file mode 100644
index 0000000..338627f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock.go
@@ -0,0 +1,26 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"errors"
+	"os"
+)
+
+var (
+	ErrLocked = errors.New("fileutil: file already locked")
+)
+
+type LockedFile struct{ *os.File }
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_flock.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_flock.go
new file mode 100644
index 0000000..542550b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_flock.go
@@ -0,0 +1,49 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows,!plan9,!solaris
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+func flockTryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB); err != nil {
+		f.Close()
+		if err == syscall.EWOULDBLOCK {
+			err = ErrLocked
+		}
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
+
+func flockLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX); err != nil {
+		f.Close()
+		return nil, err
+	}
+	return &LockedFile{f}, err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go
new file mode 100644
index 0000000..b0abc98
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_linux.go
@@ -0,0 +1,97 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build linux
+
+package fileutil
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+)
+
+// This used to call syscall.Flock() but that call fails with EBADF on NFS.
+// An alternative is lockf() which works on NFS but that call lets a process lock
+// the same file twice. Instead, use Linux's non-standard open file descriptor
+// locks which will block if the process already holds the file lock.
+//
+// constants from /usr/include/bits/fcntl-linux.h
+const (
+	F_OFD_GETLK  = 37
+	F_OFD_SETLK  = 37
+	F_OFD_SETLKW = 38
+)
+
+var (
+	wrlck = syscall.Flock_t{
+		Type:   syscall.F_WRLCK,
+		Whence: int16(io.SeekStart),
+		Start:  0,
+		Len:    0,
+	}
+
+	linuxTryLockFile = flockTryLockFile
+	linuxLockFile    = flockLockFile
+)
+
+func init() {
+	// use open file descriptor locks if the system supports it
+	getlk := syscall.Flock_t{Type: syscall.F_RDLCK}
+	if err := syscall.FcntlFlock(0, F_OFD_GETLK, &getlk); err == nil {
+		linuxTryLockFile = ofdTryLockFile
+		linuxLockFile = ofdLockFile
+	}
+}
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	return linuxTryLockFile(path, flag, perm)
+}
+
+func ofdTryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, fmt.Errorf("ofdTryLockFile failed to open %q (%v)", path, err)
+	}
+
+	flock := wrlck
+	if err = syscall.FcntlFlock(f.Fd(), F_OFD_SETLK, &flock); err != nil {
+		f.Close()
+		if err == syscall.EWOULDBLOCK {
+			err = ErrLocked
+		}
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	return linuxLockFile(path, flag, perm)
+}
+
+func ofdLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, fmt.Errorf("ofdLockFile failed to open %q (%v)", path, err)
+	}
+
+	flock := wrlck
+	err = syscall.FcntlFlock(f.Fd(), F_OFD_SETLKW, &flock)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_plan9.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_plan9.go
new file mode 100644
index 0000000..fee6a7c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_plan9.go
@@ -0,0 +1,45 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	if err := os.Chmod(path, syscall.DMEXCL|PrivateFileMode); err != nil {
+		return nil, err
+	}
+	f, err := os.Open(path, flag, perm)
+	if err != nil {
+		return nil, ErrLocked
+	}
+	return &LockedFile{f}, nil
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	if err := os.Chmod(path, syscall.DMEXCL|PrivateFileMode); err != nil {
+		return nil, err
+	}
+	for {
+		f, err := os.OpenFile(path, flag, perm)
+		if err == nil {
+			return &LockedFile{f}, nil
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_solaris.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_solaris.go
new file mode 100644
index 0000000..352ca55
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_solaris.go
@@ -0,0 +1,62 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build solaris
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Pid = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	lock.Pid = 0
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err := syscall.FcntlFlock(f.Fd(), syscall.F_SETLK, &lock); err != nil {
+		f.Close()
+		if err == syscall.EAGAIN {
+			err = ErrLocked
+		}
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Pid = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	f, err := os.OpenFile(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err = syscall.FcntlFlock(f.Fd(), syscall.F_SETLKW, &lock); err != nil {
+		f.Close()
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_unix.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_unix.go
new file mode 100644
index 0000000..ed01164
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_unix.go
@@ -0,0 +1,29 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows,!plan9,!solaris,!linux
+
+package fileutil
+
+import (
+	"os"
+)
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	return flockTryLockFile(path, flag, perm)
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	return flockLockFile(path, flag, perm)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/lock_windows.go b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_windows.go
new file mode 100644
index 0000000..b181723
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/lock_windows.go
@@ -0,0 +1,125 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build windows
+
+package fileutil
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+var (
+	modkernel32    = syscall.NewLazyDLL("kernel32.dll")
+	procLockFileEx = modkernel32.NewProc("LockFileEx")
+
+	errLocked = errors.New("The process cannot access the file because another process has locked a portion of the file.")
+)
+
+const (
+	// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx
+	LOCKFILE_EXCLUSIVE_LOCK   = 2
+	LOCKFILE_FAIL_IMMEDIATELY = 1
+
+	// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms681382(v=vs.85).aspx
+	errLockViolation syscall.Errno = 0x21
+)
+
+func TryLockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := open(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err := lockFile(syscall.Handle(f.Fd()), LOCKFILE_FAIL_IMMEDIATELY); err != nil {
+		f.Close()
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
+
+func LockFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
+	f, err := open(path, flag, perm)
+	if err != nil {
+		return nil, err
+	}
+	if err := lockFile(syscall.Handle(f.Fd()), 0); err != nil {
+		f.Close()
+		return nil, err
+	}
+	return &LockedFile{f}, nil
+}
+
+func open(path string, flag int, perm os.FileMode) (*os.File, error) {
+	if path == "" {
+		return nil, fmt.Errorf("cannot open empty filename")
+	}
+	var access uint32
+	switch flag {
+	case syscall.O_RDONLY:
+		access = syscall.GENERIC_READ
+	case syscall.O_WRONLY:
+		access = syscall.GENERIC_WRITE
+	case syscall.O_RDWR:
+		access = syscall.GENERIC_READ | syscall.GENERIC_WRITE
+	case syscall.O_WRONLY | syscall.O_CREAT:
+		access = syscall.GENERIC_ALL
+	default:
+		panic(fmt.Errorf("flag %v is not supported", flag))
+	}
+	fd, err := syscall.CreateFile(&(syscall.StringToUTF16(path)[0]),
+		access,
+		syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE|syscall.FILE_SHARE_DELETE,
+		nil,
+		syscall.OPEN_ALWAYS,
+		syscall.FILE_ATTRIBUTE_NORMAL,
+		0)
+	if err != nil {
+		return nil, err
+	}
+	return os.NewFile(uintptr(fd), path), nil
+}
+
+func lockFile(fd syscall.Handle, flags uint32) error {
+	var flag uint32 = LOCKFILE_EXCLUSIVE_LOCK
+	flag |= flags
+	if fd == syscall.InvalidHandle {
+		return nil
+	}
+	err := lockFileEx(fd, flag, 1, 0, &syscall.Overlapped{})
+	if err == nil {
+		return nil
+	} else if err.Error() == errLocked.Error() {
+		return ErrLocked
+	} else if err != errLockViolation {
+		return err
+	}
+	return nil
+}
+
+func lockFileEx(h syscall.Handle, flags, locklow, lockhigh uint32, ol *syscall.Overlapped) (err error) {
+	var reserved uint32 = 0
+	r1, _, e1 := syscall.Syscall6(procLockFileEx.Addr(), 6, uintptr(h), uintptr(flags), uintptr(reserved), uintptr(locklow), uintptr(lockhigh), uintptr(unsafe.Pointer(ol)))
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate.go b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate.go
new file mode 100644
index 0000000..c747b7c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate.go
@@ -0,0 +1,54 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"io"
+	"os"
+)
+
+// Preallocate tries to allocate the space for given
+// file. This operation is only supported on linux by a
+// few filesystems (btrfs, ext4, etc.).
+// If the operation is unsupported, no error will be returned.
+// Otherwise, the error encountered will be returned.
+func Preallocate(f *os.File, sizeInBytes int64, extendFile bool) error {
+	if sizeInBytes == 0 {
+		// fallocate will return EINVAL if length is 0; skip
+		return nil
+	}
+	if extendFile {
+		return preallocExtend(f, sizeInBytes)
+	}
+	return preallocFixed(f, sizeInBytes)
+}
+
+func preallocExtendTrunc(f *os.File, sizeInBytes int64) error {
+	curOff, err := f.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return err
+	}
+	size, err := f.Seek(sizeInBytes, io.SeekEnd)
+	if err != nil {
+		return err
+	}
+	if _, err = f.Seek(curOff, io.SeekStart); err != nil {
+		return err
+	}
+	if sizeInBytes > size {
+		return nil
+	}
+	return f.Truncate(sizeInBytes)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_darwin.go b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_darwin.go
new file mode 100644
index 0000000..5a6dccf
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_darwin.go
@@ -0,0 +1,65 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build darwin
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func preallocExtend(f *os.File, sizeInBytes int64) error {
+	if err := preallocFixed(f, sizeInBytes); err != nil {
+		return err
+	}
+	return preallocExtendTrunc(f, sizeInBytes)
+}
+
+func preallocFixed(f *os.File, sizeInBytes int64) error {
+	// allocate all requested space or no space at all
+	// TODO: allocate contiguous space on disk with F_ALLOCATECONTIG flag
+	fstore := &syscall.Fstore_t{
+		Flags:   syscall.F_ALLOCATEALL,
+		Posmode: syscall.F_PEOFPOSMODE,
+		Length:  sizeInBytes}
+	p := unsafe.Pointer(fstore)
+	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_PREALLOCATE), uintptr(p))
+	if errno == 0 || errno == syscall.ENOTSUP {
+		return nil
+	}
+
+	// wrong argument to fallocate syscall
+	if errno == syscall.EINVAL {
+		// filesystem "st_blocks" are allocated in the units of
+		// "Allocation Block Size" (run "diskutil info /" command)
+		var stat syscall.Stat_t
+		syscall.Fstat(int(f.Fd()), &stat)
+
+		// syscall.Statfs_t.Bsize is "optimal transfer block size"
+		// and contains matching 4096 value when latest OS X kernel
+		// supports 4,096 KB filesystem block size
+		var statfs syscall.Statfs_t
+		syscall.Fstatfs(int(f.Fd()), &statfs)
+		blockSize := int64(statfs.Bsize)
+
+		if stat.Blocks*blockSize >= sizeInBytes {
+			// enough blocks are already allocated
+			return nil
+		}
+	}
+	return errno
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unix.go b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unix.go
new file mode 100644
index 0000000..50bd84f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unix.go
@@ -0,0 +1,49 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build linux
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+func preallocExtend(f *os.File, sizeInBytes int64) error {
+	// use mode = 0 to change size
+	err := syscall.Fallocate(int(f.Fd()), 0, 0, sizeInBytes)
+	if err != nil {
+		errno, ok := err.(syscall.Errno)
+		// not supported; fallback
+		// fallocate EINTRs frequently in some environments; fallback
+		if ok && (errno == syscall.ENOTSUP || errno == syscall.EINTR) {
+			return preallocExtendTrunc(f, sizeInBytes)
+		}
+	}
+	return err
+}
+
+func preallocFixed(f *os.File, sizeInBytes int64) error {
+	// use mode = 1 to keep size; see FALLOC_FL_KEEP_SIZE
+	err := syscall.Fallocate(int(f.Fd()), 1, 0, sizeInBytes)
+	if err != nil {
+		errno, ok := err.(syscall.Errno)
+		// treat not supported as nil error
+		if ok && errno == syscall.ENOTSUP {
+			return nil
+		}
+	}
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unsupported.go b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unsupported.go
new file mode 100644
index 0000000..162fbc5
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/preallocate_unsupported.go
@@ -0,0 +1,25 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux,!darwin
+
+package fileutil
+
+import "os"
+
+func preallocExtend(f *os.File, sizeInBytes int64) error {
+	return preallocExtendTrunc(f, sizeInBytes)
+}
+
+func preallocFixed(f *os.File, sizeInBytes int64) error { return nil }
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/purge.go b/vendor/go.etcd.io/etcd/pkg/fileutil/purge.go
new file mode 100644
index 0000000..fda96c3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/purge.go
@@ -0,0 +1,88 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+func PurgeFile(lg *zap.Logger, dirname string, suffix string, max uint, interval time.Duration, stop <-chan struct{}) <-chan error {
+	return purgeFile(lg, dirname, suffix, max, interval, stop, nil)
+}
+
+// purgeFile is the internal implementation for PurgeFile which can post purged files to purgec if non-nil.
+func purgeFile(lg *zap.Logger, dirname string, suffix string, max uint, interval time.Duration, stop <-chan struct{}, purgec chan<- string) <-chan error {
+	errC := make(chan error, 1)
+	go func() {
+		for {
+			fnames, err := ReadDir(dirname)
+			if err != nil {
+				errC <- err
+				return
+			}
+			newfnames := make([]string, 0)
+			for _, fname := range fnames {
+				if strings.HasSuffix(fname, suffix) {
+					newfnames = append(newfnames, fname)
+				}
+			}
+			sort.Strings(newfnames)
+			fnames = newfnames
+			for len(newfnames) > int(max) {
+				f := filepath.Join(dirname, newfnames[0])
+				l, err := TryLockFile(f, os.O_WRONLY, PrivateFileMode)
+				if err != nil {
+					break
+				}
+				if err = os.Remove(f); err != nil {
+					errC <- err
+					return
+				}
+				if err = l.Close(); err != nil {
+					if lg != nil {
+						lg.Warn("failed to unlock/close", zap.String("path", l.Name()), zap.Error(err))
+					} else {
+						plog.Errorf("error unlocking %s when purging file (%v)", l.Name(), err)
+					}
+					errC <- err
+					return
+				}
+				if lg != nil {
+					lg.Info("purged", zap.String("path", f))
+				} else {
+					plog.Infof("purged file %s successfully", f)
+				}
+				newfnames = newfnames[1:]
+			}
+			if purgec != nil {
+				for i := 0; i < len(fnames)-len(newfnames); i++ {
+					purgec <- fnames[i]
+				}
+			}
+			select {
+			case <-time.After(interval):
+			case <-stop:
+				return
+			}
+		}
+	}()
+	return errC
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/read_dir.go b/vendor/go.etcd.io/etcd/pkg/fileutil/read_dir.go
new file mode 100644
index 0000000..2eeaa89
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/read_dir.go
@@ -0,0 +1,70 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fileutil
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+)
+
+// ReadDirOp represents an read-directory operation.
+type ReadDirOp struct {
+	ext string
+}
+
+// ReadDirOption configures archiver operations.
+type ReadDirOption func(*ReadDirOp)
+
+// WithExt filters file names by their extensions.
+// (e.g. WithExt(".wal") to list only WAL files)
+func WithExt(ext string) ReadDirOption {
+	return func(op *ReadDirOp) { op.ext = ext }
+}
+
+func (op *ReadDirOp) applyOpts(opts []ReadDirOption) {
+	for _, opt := range opts {
+		opt(op)
+	}
+}
+
+// ReadDir returns the filenames in the given directory in sorted order.
+func ReadDir(d string, opts ...ReadDirOption) ([]string, error) {
+	op := &ReadDirOp{}
+	op.applyOpts(opts)
+
+	dir, err := os.Open(d)
+	if err != nil {
+		return nil, err
+	}
+	defer dir.Close()
+
+	names, err := dir.Readdirnames(-1)
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(names)
+
+	if op.ext != "" {
+		tss := make([]string, 0)
+		for _, v := range names {
+			if filepath.Ext(v) == op.ext {
+				tss = append(tss, v)
+			}
+		}
+		names = tss
+	}
+	return names, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/sync.go b/vendor/go.etcd.io/etcd/pkg/fileutil/sync.go
new file mode 100644
index 0000000..54dd41f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/sync.go
@@ -0,0 +1,29 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux,!darwin
+
+package fileutil
+
+import "os"
+
+// Fsync is a wrapper around file.Sync(). Special handling is needed on darwin platform.
+func Fsync(f *os.File) error {
+	return f.Sync()
+}
+
+// Fdatasync is a wrapper around file.Sync(). Special handling is needed on linux platform.
+func Fdatasync(f *os.File) error {
+	return f.Sync()
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/sync_darwin.go b/vendor/go.etcd.io/etcd/pkg/fileutil/sync_darwin.go
new file mode 100644
index 0000000..c2f39bf
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/sync_darwin.go
@@ -0,0 +1,40 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build darwin
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// Fsync on HFS/OSX flushes the data on to the physical drive but the drive
+// may not write it to the persistent media for quite sometime and it may be
+// written in out-of-order sequence. Using F_FULLFSYNC ensures that the
+// physical drive's buffer will also get flushed to the media.
+func Fsync(f *os.File) error {
+	_, _, errno := syscall.Syscall(syscall.SYS_FCNTL, f.Fd(), uintptr(syscall.F_FULLFSYNC), uintptr(0))
+	if errno == 0 {
+		return nil
+	}
+	return errno
+}
+
+// Fdatasync on darwin platform invokes fcntl(F_FULLFSYNC) for actual persistence
+// on physical drive media.
+func Fdatasync(f *os.File) error {
+	return Fsync(f)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/fileutil/sync_linux.go b/vendor/go.etcd.io/etcd/pkg/fileutil/sync_linux.go
new file mode 100644
index 0000000..1bbced9
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/fileutil/sync_linux.go
@@ -0,0 +1,34 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build linux
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// Fsync is a wrapper around file.Sync(). Special handling is needed on darwin platform.
+func Fsync(f *os.File) error {
+	return f.Sync()
+}
+
+// Fdatasync is similar to fsync(), but does not flush modified metadata
+// unless that metadata is needed in order to allow a subsequent data retrieval
+// to be correctly handled.
+func Fdatasync(f *os.File) error {
+	return syscall.Fdatasync(int(f.Fd()))
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/flag.go b/vendor/go.etcd.io/etcd/pkg/flags/flag.go
new file mode 100644
index 0000000..215902c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/flag.go
@@ -0,0 +1,121 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package flags implements command-line flag parsing.
+package flags
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/coreos/pkg/capnslog"
+	"github.com/spf13/pflag"
+)
+
+var plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "pkg/flags")
+
+// SetFlagsFromEnv parses all registered flags in the given flagset,
+// and if they are not already set it attempts to set their values from
+// environment variables. Environment variables take the name of the flag but
+// are UPPERCASE, have the given prefix  and any dashes are replaced by
+// underscores - for example: some-flag => ETCD_SOME_FLAG
+func SetFlagsFromEnv(prefix string, fs *flag.FlagSet) error {
+	var err error
+	alreadySet := make(map[string]bool)
+	fs.Visit(func(f *flag.Flag) {
+		alreadySet[FlagToEnv(prefix, f.Name)] = true
+	})
+	usedEnvKey := make(map[string]bool)
+	fs.VisitAll(func(f *flag.Flag) {
+		if serr := setFlagFromEnv(fs, prefix, f.Name, usedEnvKey, alreadySet, true); serr != nil {
+			err = serr
+		}
+	})
+	verifyEnv(prefix, usedEnvKey, alreadySet)
+	return err
+}
+
+// SetPflagsFromEnv is similar to SetFlagsFromEnv. However, the accepted flagset type is pflag.FlagSet
+// and it does not do any logging.
+func SetPflagsFromEnv(prefix string, fs *pflag.FlagSet) error {
+	var err error
+	alreadySet := make(map[string]bool)
+	usedEnvKey := make(map[string]bool)
+	fs.VisitAll(func(f *pflag.Flag) {
+		if f.Changed {
+			alreadySet[FlagToEnv(prefix, f.Name)] = true
+		}
+		if serr := setFlagFromEnv(fs, prefix, f.Name, usedEnvKey, alreadySet, false); serr != nil {
+			err = serr
+		}
+	})
+	verifyEnv(prefix, usedEnvKey, alreadySet)
+	return err
+}
+
+// FlagToEnv converts flag string to upper-case environment variable key string.
+func FlagToEnv(prefix, name string) string {
+	return prefix + "_" + strings.ToUpper(strings.Replace(name, "-", "_", -1))
+}
+
+func verifyEnv(prefix string, usedEnvKey, alreadySet map[string]bool) {
+	for _, env := range os.Environ() {
+		kv := strings.SplitN(env, "=", 2)
+		if len(kv) != 2 {
+			plog.Warningf("found invalid env %s", env)
+		}
+		if usedEnvKey[kv[0]] {
+			continue
+		}
+		if alreadySet[kv[0]] {
+			plog.Fatalf("conflicting environment variable %q is shadowed by corresponding command-line flag (either unset environment variable or disable flag)", kv[0])
+		}
+		if strings.HasPrefix(env, prefix+"_") {
+			plog.Warningf("unrecognized environment variable %s", env)
+		}
+	}
+}
+
+type flagSetter interface {
+	Set(fk string, fv string) error
+}
+
+func setFlagFromEnv(fs flagSetter, prefix, fname string, usedEnvKey, alreadySet map[string]bool, log bool) error {
+	key := FlagToEnv(prefix, fname)
+	if !alreadySet[key] {
+		val := os.Getenv(key)
+		if val != "" {
+			usedEnvKey[key] = true
+			if serr := fs.Set(fname, val); serr != nil {
+				return fmt.Errorf("invalid value %q for %s: %v", val, key, serr)
+			}
+			if log {
+				plog.Infof("recognized and used environment variable %s=%s", key, val)
+			}
+		}
+	}
+	return nil
+}
+
+func IsSet(fs *flag.FlagSet, name string) bool {
+	set := false
+	fs.Visit(func(f *flag.Flag) {
+		if f.Name == name {
+			set = true
+		}
+	})
+	return set
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/ignored.go b/vendor/go.etcd.io/etcd/pkg/flags/ignored.go
new file mode 100644
index 0000000..9953049
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/ignored.go
@@ -0,0 +1,36 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+// IgnoredFlag encapsulates a flag that may have been previously valid but is
+// now ignored. If an IgnoredFlag is set, a warning is printed and
+// operation continues.
+type IgnoredFlag struct {
+	Name string
+}
+
+// IsBoolFlag is defined to allow the flag to be defined without an argument
+func (f *IgnoredFlag) IsBoolFlag() bool {
+	return true
+}
+
+func (f *IgnoredFlag) Set(s string) error {
+	plog.Warningf(`flag "-%s" is no longer supported - ignoring.`, f.Name)
+	return nil
+}
+
+func (f *IgnoredFlag) String() string {
+	return ""
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/selective_string.go b/vendor/go.etcd.io/etcd/pkg/flags/selective_string.go
new file mode 100644
index 0000000..4b90fbf
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/selective_string.go
@@ -0,0 +1,114 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// SelectiveStringValue implements the flag.Value interface.
+type SelectiveStringValue struct {
+	v      string
+	valids map[string]struct{}
+}
+
+// Set verifies the argument to be a valid member of the allowed values
+// before setting the underlying flag value.
+func (ss *SelectiveStringValue) Set(s string) error {
+	if _, ok := ss.valids[s]; ok {
+		ss.v = s
+		return nil
+	}
+	return errors.New("invalid value")
+}
+
+// String returns the set value (if any) of the SelectiveStringValue
+func (ss *SelectiveStringValue) String() string {
+	return ss.v
+}
+
+// Valids returns the list of valid strings.
+func (ss *SelectiveStringValue) Valids() []string {
+	s := make([]string, 0, len(ss.valids))
+	for k := range ss.valids {
+		s = append(s, k)
+	}
+	sort.Strings(s)
+	return s
+}
+
+// NewSelectiveStringValue creates a new string flag
+// for which any one of the given strings is a valid value,
+// and any other value is an error.
+//
+// valids[0] will be default value. Caller must be sure
+// len(valids) != 0 or it will panic.
+func NewSelectiveStringValue(valids ...string) *SelectiveStringValue {
+	vm := make(map[string]struct{})
+	for _, v := range valids {
+		vm[v] = struct{}{}
+	}
+	return &SelectiveStringValue{valids: vm, v: valids[0]}
+}
+
+// SelectiveStringsValue implements the flag.Value interface.
+type SelectiveStringsValue struct {
+	vs     []string
+	valids map[string]struct{}
+}
+
+// Set verifies the argument to be a valid member of the allowed values
+// before setting the underlying flag value.
+func (ss *SelectiveStringsValue) Set(s string) error {
+	vs := strings.Split(s, ",")
+	for i := range vs {
+		if _, ok := ss.valids[vs[i]]; ok {
+			ss.vs = append(ss.vs, vs[i])
+		} else {
+			return fmt.Errorf("invalid value %q", vs[i])
+		}
+	}
+	sort.Strings(ss.vs)
+	return nil
+}
+
+// String returns the set value (if any) of the SelectiveStringsValue.
+func (ss *SelectiveStringsValue) String() string {
+	return strings.Join(ss.vs, ",")
+}
+
+// Valids returns the list of valid strings.
+func (ss *SelectiveStringsValue) Valids() []string {
+	s := make([]string, 0, len(ss.valids))
+	for k := range ss.valids {
+		s = append(s, k)
+	}
+	sort.Strings(s)
+	return s
+}
+
+// NewSelectiveStringsValue creates a new string slice flag
+// for which any one of the given strings is a valid value,
+// and any other value is an error.
+func NewSelectiveStringsValue(valids ...string) *SelectiveStringsValue {
+	vm := make(map[string]struct{})
+	for _, v := range valids {
+		vm[v] = struct{}{}
+	}
+	return &SelectiveStringsValue{valids: vm, vs: []string{}}
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/strings.go b/vendor/go.etcd.io/etcd/pkg/flags/strings.go
new file mode 100644
index 0000000..3e47fb3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/strings.go
@@ -0,0 +1,52 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+import (
+	"flag"
+	"sort"
+	"strings"
+)
+
+// StringsValue wraps "sort.StringSlice".
+type StringsValue sort.StringSlice
+
+// Set parses a command line set of strings, separated by comma.
+// Implements "flag.Value" interface.
+func (ss *StringsValue) Set(s string) error {
+	*ss = strings.Split(s, ",")
+	return nil
+}
+
+// String implements "flag.Value" interface.
+func (ss *StringsValue) String() string { return strings.Join(*ss, ",") }
+
+// NewStringsValue implements string slice as "flag.Value" interface.
+// Given value is to be separated by comma.
+func NewStringsValue(s string) (ss *StringsValue) {
+	if s == "" {
+		return &StringsValue{}
+	}
+	ss = new(StringsValue)
+	if err := ss.Set(s); err != nil {
+		plog.Panicf("new StringsValue should never fail: %v", err)
+	}
+	return ss
+}
+
+// StringsFromFlag returns a string slice from the flag.
+func StringsFromFlag(fs *flag.FlagSet, flagName string) []string {
+	return []string(*fs.Lookup(flagName).Value.(*StringsValue))
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/unique_strings.go b/vendor/go.etcd.io/etcd/pkg/flags/unique_strings.go
new file mode 100644
index 0000000..e220ee0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/unique_strings.go
@@ -0,0 +1,76 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+import (
+	"flag"
+	"sort"
+	"strings"
+)
+
+// UniqueStringsValue wraps a list of unique strings.
+// The values are set in order.
+type UniqueStringsValue struct {
+	Values map[string]struct{}
+}
+
+// Set parses a command line set of strings, separated by comma.
+// Implements "flag.Value" interface.
+// The values are set in order.
+func (us *UniqueStringsValue) Set(s string) error {
+	us.Values = make(map[string]struct{})
+	for _, v := range strings.Split(s, ",") {
+		us.Values[v] = struct{}{}
+	}
+	return nil
+}
+
+// String implements "flag.Value" interface.
+func (us *UniqueStringsValue) String() string {
+	return strings.Join(us.stringSlice(), ",")
+}
+
+func (us *UniqueStringsValue) stringSlice() []string {
+	ss := make([]string, 0, len(us.Values))
+	for v := range us.Values {
+		ss = append(ss, v)
+	}
+	sort.Strings(ss)
+	return ss
+}
+
+// NewUniqueStringsValue implements string slice as "flag.Value" interface.
+// Given value is to be separated by comma.
+// The values are set in order.
+func NewUniqueStringsValue(s string) (us *UniqueStringsValue) {
+	us = &UniqueStringsValue{Values: make(map[string]struct{})}
+	if s == "" {
+		return us
+	}
+	if err := us.Set(s); err != nil {
+		plog.Panicf("new UniqueStringsValue should never fail: %v", err)
+	}
+	return us
+}
+
+// UniqueStringsFromFlag returns a string slice from the flag.
+func UniqueStringsFromFlag(fs *flag.FlagSet, flagName string) []string {
+	return (*fs.Lookup(flagName).Value.(*UniqueStringsValue)).stringSlice()
+}
+
+// UniqueStringsMapFromFlag returns a map of strings from the flag.
+func UniqueStringsMapFromFlag(fs *flag.FlagSet, flagName string) map[string]struct{} {
+	return (*fs.Lookup(flagName).Value.(*UniqueStringsValue)).Values
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/unique_urls.go b/vendor/go.etcd.io/etcd/pkg/flags/unique_urls.go
new file mode 100644
index 0000000..9b4178c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/unique_urls.go
@@ -0,0 +1,92 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+import (
+	"flag"
+	"net/url"
+	"sort"
+	"strings"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+// UniqueURLs contains unique URLs
+// with non-URL exceptions.
+type UniqueURLs struct {
+	Values  map[string]struct{}
+	uss     []url.URL
+	Allowed map[string]struct{}
+}
+
+// Set parses a command line set of URLs formatted like:
+// http://127.0.0.1:2380,http://10.1.1.2:80
+// Implements "flag.Value" interface.
+func (us *UniqueURLs) Set(s string) error {
+	if _, ok := us.Values[s]; ok {
+		return nil
+	}
+	if _, ok := us.Allowed[s]; ok {
+		us.Values[s] = struct{}{}
+		return nil
+	}
+	ss, err := types.NewURLs(strings.Split(s, ","))
+	if err != nil {
+		return err
+	}
+	us.Values = make(map[string]struct{})
+	us.uss = make([]url.URL, 0)
+	for _, v := range ss {
+		us.Values[v.String()] = struct{}{}
+		us.uss = append(us.uss, v)
+	}
+	return nil
+}
+
+// String implements "flag.Value" interface.
+func (us *UniqueURLs) String() string {
+	all := make([]string, 0, len(us.Values))
+	for u := range us.Values {
+		all = append(all, u)
+	}
+	sort.Strings(all)
+	return strings.Join(all, ",")
+}
+
+// NewUniqueURLsWithExceptions implements "url.URL" slice as flag.Value interface.
+// Given value is to be separated by comma.
+func NewUniqueURLsWithExceptions(s string, exceptions ...string) *UniqueURLs {
+	us := &UniqueURLs{Values: make(map[string]struct{}), Allowed: make(map[string]struct{})}
+	for _, v := range exceptions {
+		us.Allowed[v] = struct{}{}
+	}
+	if s == "" {
+		return us
+	}
+	if err := us.Set(s); err != nil {
+		plog.Panicf("new UniqueURLs should never fail: %v", err)
+	}
+	return us
+}
+
+// UniqueURLsFromFlag returns a slice from urls got from the flag.
+func UniqueURLsFromFlag(fs *flag.FlagSet, urlsFlagName string) []url.URL {
+	return (*fs.Lookup(urlsFlagName).Value.(*UniqueURLs)).uss
+}
+
+// UniqueURLsMapFromFlag returns a map from url strings got from the flag.
+func UniqueURLsMapFromFlag(fs *flag.FlagSet, urlsFlagName string) map[string]struct{} {
+	return (*fs.Lookup(urlsFlagName).Value.(*UniqueURLs)).Values
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/flags/urls.go b/vendor/go.etcd.io/etcd/pkg/flags/urls.go
new file mode 100644
index 0000000..ca90970
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/flags/urls.go
@@ -0,0 +1,65 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package flags
+
+import (
+	"flag"
+	"net/url"
+	"strings"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+// URLsValue wraps "types.URLs".
+type URLsValue types.URLs
+
+// Set parses a command line set of URLs formatted like:
+// http://127.0.0.1:2380,http://10.1.1.2:80
+// Implements "flag.Value" interface.
+func (us *URLsValue) Set(s string) error {
+	ss, err := types.NewURLs(strings.Split(s, ","))
+	if err != nil {
+		return err
+	}
+	*us = URLsValue(ss)
+	return nil
+}
+
+// String implements "flag.Value" interface.
+func (us *URLsValue) String() string {
+	all := make([]string, len(*us))
+	for i, u := range *us {
+		all[i] = u.String()
+	}
+	return strings.Join(all, ",")
+}
+
+// NewURLsValue implements "url.URL" slice as flag.Value interface.
+// Given value is to be separated by comma.
+func NewURLsValue(s string) *URLsValue {
+	if s == "" {
+		return &URLsValue{}
+	}
+	v := &URLsValue{}
+	if err := v.Set(s); err != nil {
+		plog.Panicf("new URLsValue should never fail: %v", err)
+	}
+	return v
+}
+
+// URLsFromFlag returns a slices from url got from the flag.
+func URLsFromFlag(fs *flag.FlagSet, urlsFlagName string) []url.URL {
+	return []url.URL(*fs.Lookup(urlsFlagName).Value.(*URLsValue))
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/httputil/httputil.go b/vendor/go.etcd.io/etcd/pkg/httputil/httputil.go
new file mode 100644
index 0000000..3bf58a3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/httputil/httputil.go
@@ -0,0 +1,50 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package httputil provides HTTP utility functions.
+package httputil
+
+import (
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+)
+
+// GracefulClose drains http.Response.Body until it hits EOF
+// and closes it. This prevents TCP/TLS connections from closing,
+// therefore available for reuse.
+// Borrowed from golang/net/context/ctxhttp/cancelreq.go.
+func GracefulClose(resp *http.Response) {
+	io.Copy(ioutil.Discard, resp.Body)
+	resp.Body.Close()
+}
+
+// GetHostname returns the hostname from request Host field.
+// It returns empty string, if Host field contains invalid
+// value (e.g. "localhost:::" with too many colons).
+func GetHostname(req *http.Request) string {
+	if req == nil {
+		return ""
+	}
+	h, _, err := net.SplitHostPort(req.Host)
+	if err != nil {
+		return req.Host
+	}
+	return h
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/idutil/id.go b/vendor/go.etcd.io/etcd/pkg/idutil/id.go
new file mode 100644
index 0000000..63a02cd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/idutil/id.go
@@ -0,0 +1,75 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package idutil implements utility functions for generating unique,
+// randomized ids.
+package idutil
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+)
+
+const (
+	tsLen     = 5 * 8
+	cntLen    = 8
+	suffixLen = tsLen + cntLen
+)
+
+// Generator generates unique identifiers based on counters, timestamps, and
+// a node member ID.
+//
+// The initial id is in this format:
+// High order 2 bytes are from memberID, next 5 bytes are from timestamp,
+// and low order one byte is a counter.
+// | prefix   | suffix              |
+// | 2 bytes  | 5 bytes   | 1 byte  |
+// | memberID | timestamp | cnt     |
+//
+// The timestamp 5 bytes is different when the machine is restart
+// after 1 ms and before 35 years.
+//
+// It increases suffix to generate the next id.
+// The count field may overflow to timestamp field, which is intentional.
+// It helps to extend the event window to 2^56. This doesn't break that
+// id generated after restart is unique because etcd throughput is <<
+// 256req/ms(250k reqs/second).
+type Generator struct {
+	// high order 2 bytes
+	prefix uint64
+	// low order 6 bytes
+	suffix uint64
+}
+
+func NewGenerator(memberID uint16, now time.Time) *Generator {
+	prefix := uint64(memberID) << suffixLen
+	unixMilli := uint64(now.UnixNano()) / uint64(time.Millisecond/time.Nanosecond)
+	suffix := lowbit(unixMilli, tsLen) << cntLen
+	return &Generator{
+		prefix: prefix,
+		suffix: suffix,
+	}
+}
+
+// Next generates a id that is unique.
+func (g *Generator) Next() uint64 {
+	suffix := atomic.AddUint64(&g.suffix, 1)
+	id := g.prefix | lowbit(suffix, suffixLen)
+	return id
+}
+
+func lowbit(x uint64, n uint) uint64 {
+	return x & (math.MaxUint64 >> (64 - n))
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/ioutil/pagewriter.go b/vendor/go.etcd.io/etcd/pkg/ioutil/pagewriter.go
new file mode 100644
index 0000000..72de159
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/ioutil/pagewriter.go
@@ -0,0 +1,106 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ioutil
+
+import (
+	"io"
+)
+
+var defaultBufferBytes = 128 * 1024
+
+// PageWriter implements the io.Writer interface so that writes will
+// either be in page chunks or from flushing.
+type PageWriter struct {
+	w io.Writer
+	// pageOffset tracks the page offset of the base of the buffer
+	pageOffset int
+	// pageBytes is the number of bytes per page
+	pageBytes int
+	// bufferedBytes counts the number of bytes pending for write in the buffer
+	bufferedBytes int
+	// buf holds the write buffer
+	buf []byte
+	// bufWatermarkBytes is the number of bytes the buffer can hold before it needs
+	// to be flushed. It is less than len(buf) so there is space for slack writes
+	// to bring the writer to page alignment.
+	bufWatermarkBytes int
+}
+
+// NewPageWriter creates a new PageWriter. pageBytes is the number of bytes
+// to write per page. pageOffset is the starting offset of io.Writer.
+func NewPageWriter(w io.Writer, pageBytes, pageOffset int) *PageWriter {
+	return &PageWriter{
+		w:                 w,
+		pageOffset:        pageOffset,
+		pageBytes:         pageBytes,
+		buf:               make([]byte, defaultBufferBytes+pageBytes),
+		bufWatermarkBytes: defaultBufferBytes,
+	}
+}
+
+func (pw *PageWriter) Write(p []byte) (n int, err error) {
+	if len(p)+pw.bufferedBytes <= pw.bufWatermarkBytes {
+		// no overflow
+		copy(pw.buf[pw.bufferedBytes:], p)
+		pw.bufferedBytes += len(p)
+		return len(p), nil
+	}
+	// complete the slack page in the buffer if unaligned
+	slack := pw.pageBytes - ((pw.pageOffset + pw.bufferedBytes) % pw.pageBytes)
+	if slack != pw.pageBytes {
+		partial := slack > len(p)
+		if partial {
+			// not enough data to complete the slack page
+			slack = len(p)
+		}
+		// special case: writing to slack page in buffer
+		copy(pw.buf[pw.bufferedBytes:], p[:slack])
+		pw.bufferedBytes += slack
+		n = slack
+		p = p[slack:]
+		if partial {
+			// avoid forcing an unaligned flush
+			return n, nil
+		}
+	}
+	// buffer contents are now page-aligned; clear out
+	if err = pw.Flush(); err != nil {
+		return n, err
+	}
+	// directly write all complete pages without copying
+	if len(p) > pw.pageBytes {
+		pages := len(p) / pw.pageBytes
+		c, werr := pw.w.Write(p[:pages*pw.pageBytes])
+		n += c
+		if werr != nil {
+			return n, werr
+		}
+		p = p[pages*pw.pageBytes:]
+	}
+	// write remaining tail to buffer
+	c, werr := pw.Write(p)
+	n += c
+	return n, werr
+}
+
+func (pw *PageWriter) Flush() error {
+	if pw.bufferedBytes == 0 {
+		return nil
+	}
+	_, err := pw.w.Write(pw.buf[:pw.bufferedBytes])
+	pw.pageOffset = (pw.pageOffset + pw.bufferedBytes) % pw.pageBytes
+	pw.bufferedBytes = 0
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/ioutil/readcloser.go b/vendor/go.etcd.io/etcd/pkg/ioutil/readcloser.go
new file mode 100644
index 0000000..d3efcfe
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/ioutil/readcloser.go
@@ -0,0 +1,66 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ioutil
+
+import (
+	"fmt"
+	"io"
+)
+
+// ReaderAndCloser implements io.ReadCloser interface by combining
+// reader and closer together.
+type ReaderAndCloser struct {
+	io.Reader
+	io.Closer
+}
+
+var (
+	ErrShortRead = fmt.Errorf("ioutil: short read")
+	ErrExpectEOF = fmt.Errorf("ioutil: expect EOF")
+)
+
+// NewExactReadCloser returns a ReadCloser that returns errors if the underlying
+// reader does not read back exactly the requested number of bytes.
+func NewExactReadCloser(rc io.ReadCloser, totalBytes int64) io.ReadCloser {
+	return &exactReadCloser{rc: rc, totalBytes: totalBytes}
+}
+
+type exactReadCloser struct {
+	rc         io.ReadCloser
+	br         int64
+	totalBytes int64
+}
+
+func (e *exactReadCloser) Read(p []byte) (int, error) {
+	n, err := e.rc.Read(p)
+	e.br += int64(n)
+	if e.br > e.totalBytes {
+		return 0, ErrExpectEOF
+	}
+	if e.br < e.totalBytes && n == 0 {
+		return 0, ErrShortRead
+	}
+	return n, err
+}
+
+func (e *exactReadCloser) Close() error {
+	if err := e.rc.Close(); err != nil {
+		return err
+	}
+	if e.br < e.totalBytes {
+		return ErrShortRead
+	}
+	return nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/ioutil/reader.go b/vendor/go.etcd.io/etcd/pkg/ioutil/reader.go
new file mode 100644
index 0000000..0703ed4
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/ioutil/reader.go
@@ -0,0 +1,40 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package ioutil implements I/O utility functions.
+package ioutil
+
+import "io"
+
+// NewLimitedBufferReader returns a reader that reads from the given reader
+// but limits the amount of data returned to at most n bytes.
+func NewLimitedBufferReader(r io.Reader, n int) io.Reader {
+	return &limitedBufferReader{
+		r: r,
+		n: n,
+	}
+}
+
+type limitedBufferReader struct {
+	r io.Reader
+	n int
+}
+
+func (r *limitedBufferReader) Read(p []byte) (n int, err error) {
+	np := p
+	if len(np) > r.n {
+		np = np[:r.n]
+	}
+	return r.r.Read(np)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/ioutil/util.go b/vendor/go.etcd.io/etcd/pkg/ioutil/util.go
new file mode 100644
index 0000000..6a6746e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/ioutil/util.go
@@ -0,0 +1,43 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ioutil
+
+import (
+	"io"
+	"os"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+)
+
+// WriteAndSyncFile behaves just like ioutil.WriteFile in the standard library,
+// but calls Sync before closing the file. WriteAndSyncFile guarantees the data
+// is synced if there is no error returned.
+func WriteAndSyncFile(filename string, data []byte, perm os.FileMode) error {
+	f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+	}
+	if err == nil {
+		err = fileutil.Fsync(f)
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/doc.go b/vendor/go.etcd.io/etcd/pkg/netutil/doc.go
new file mode 100644
index 0000000..5d92d03
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package netutil implements network-related utility functions.
+package netutil
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/isolate_linux.go b/vendor/go.etcd.io/etcd/pkg/netutil/isolate_linux.go
new file mode 100644
index 0000000..418580a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/isolate_linux.go
@@ -0,0 +1,82 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package netutil
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+// DropPort drops all tcp packets that are received from the given port and sent to the given port.
+func DropPort(port int) error {
+	cmdStr := fmt.Sprintf("sudo iptables -A OUTPUT -p tcp --destination-port %d -j DROP", port)
+	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
+		return err
+	}
+	cmdStr = fmt.Sprintf("sudo iptables -A INPUT -p tcp --destination-port %d -j DROP", port)
+	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
+	return err
+}
+
+// RecoverPort stops dropping tcp packets at given port.
+func RecoverPort(port int) error {
+	cmdStr := fmt.Sprintf("sudo iptables -D OUTPUT -p tcp --destination-port %d -j DROP", port)
+	if _, err := exec.Command("/bin/sh", "-c", cmdStr).Output(); err != nil {
+		return err
+	}
+	cmdStr = fmt.Sprintf("sudo iptables -D INPUT -p tcp --destination-port %d -j DROP", port)
+	_, err := exec.Command("/bin/sh", "-c", cmdStr).Output()
+	return err
+}
+
+// SetLatency adds latency in millisecond scale with random variations.
+func SetLatency(ms, rv int) error {
+	ifces, err := GetDefaultInterfaces()
+	if err != nil {
+		return err
+	}
+
+	if rv > ms {
+		rv = 1
+	}
+	for ifce := range ifces {
+		cmdStr := fmt.Sprintf("sudo tc qdisc add dev %s root netem delay %dms %dms distribution normal", ifce, ms, rv)
+		_, err = exec.Command("/bin/sh", "-c", cmdStr).Output()
+		if err != nil {
+			// the rule has already been added. Overwrite it.
+			cmdStr = fmt.Sprintf("sudo tc qdisc change dev %s root netem delay %dms %dms distribution normal", ifce, ms, rv)
+			_, err = exec.Command("/bin/sh", "-c", cmdStr).Output()
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// RemoveLatency resets latency configurations.
+func RemoveLatency() error {
+	ifces, err := GetDefaultInterfaces()
+	if err != nil {
+		return err
+	}
+	for ifce := range ifces {
+		_, err = exec.Command("/bin/sh", "-c", fmt.Sprintf("sudo tc qdisc del dev %s root netem", ifce)).Output()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/isolate_stub.go b/vendor/go.etcd.io/etcd/pkg/netutil/isolate_stub.go
new file mode 100644
index 0000000..7f4c3e6
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/isolate_stub.go
@@ -0,0 +1,25 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux
+
+package netutil
+
+func DropPort(port int) error { return nil }
+
+func RecoverPort(port int) error { return nil }
+
+func SetLatency(ms, rv int) error { return nil }
+
+func RemoveLatency() error { return nil }
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/netutil.go b/vendor/go.etcd.io/etcd/pkg/netutil/netutil.go
new file mode 100644
index 0000000..faef646
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/netutil.go
@@ -0,0 +1,213 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package netutil
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+	"reflect"
+	"sort"
+	"time"
+
+	"go.etcd.io/etcd/pkg/types"
+
+	"go.uber.org/zap"
+)
+
+// indirection for testing
+var resolveTCPAddr = resolveTCPAddrDefault
+
+const retryInterval = time.Second
+
+// taken from go's ResolveTCP code but uses configurable ctx
+func resolveTCPAddrDefault(ctx context.Context, addr string) (*net.TCPAddr, error) {
+	host, port, serr := net.SplitHostPort(addr)
+	if serr != nil {
+		return nil, serr
+	}
+	portnum, perr := net.DefaultResolver.LookupPort(ctx, "tcp", port)
+	if perr != nil {
+		return nil, perr
+	}
+
+	var ips []net.IPAddr
+	if ip := net.ParseIP(host); ip != nil {
+		ips = []net.IPAddr{{IP: ip}}
+	} else {
+		// Try as a DNS name.
+		ipss, err := net.DefaultResolver.LookupIPAddr(ctx, host)
+		if err != nil {
+			return nil, err
+		}
+		ips = ipss
+	}
+	// randomize?
+	ip := ips[0]
+	return &net.TCPAddr{IP: ip.IP, Port: portnum, Zone: ip.Zone}, nil
+}
+
+// resolveTCPAddrs is a convenience wrapper for net.ResolveTCPAddr.
+// resolveTCPAddrs return a new set of url.URLs, in which all DNS hostnames
+// are resolved.
+func resolveTCPAddrs(ctx context.Context, lg *zap.Logger, urls [][]url.URL) ([][]url.URL, error) {
+	newurls := make([][]url.URL, 0)
+	for _, us := range urls {
+		nus := make([]url.URL, len(us))
+		for i, u := range us {
+			nu, err := url.Parse(u.String())
+			if err != nil {
+				return nil, fmt.Errorf("failed to parse %q (%v)", u.String(), err)
+			}
+			nus[i] = *nu
+		}
+		for i, u := range nus {
+			h, err := resolveURL(ctx, lg, u)
+			if err != nil {
+				return nil, fmt.Errorf("failed to resolve %q (%v)", u.String(), err)
+			}
+			if h != "" {
+				nus[i].Host = h
+			}
+		}
+		newurls = append(newurls, nus)
+	}
+	return newurls, nil
+}
+
+func resolveURL(ctx context.Context, lg *zap.Logger, u url.URL) (string, error) {
+	if u.Scheme == "unix" || u.Scheme == "unixs" {
+		// unix sockets don't resolve over TCP
+		return "", nil
+	}
+	host, _, err := net.SplitHostPort(u.Host)
+	if err != nil {
+		lg.Warn(
+			"failed to parse URL Host while resolving URL",
+			zap.String("url", u.String()),
+			zap.String("host", u.Host),
+			zap.Error(err),
+		)
+		return "", err
+	}
+	if host == "localhost" || net.ParseIP(host) != nil {
+		return "", nil
+	}
+	for ctx.Err() == nil {
+		tcpAddr, err := resolveTCPAddr(ctx, u.Host)
+		if err == nil {
+			lg.Info(
+				"resolved URL Host",
+				zap.String("url", u.String()),
+				zap.String("host", u.Host),
+				zap.String("resolved-addr", tcpAddr.String()),
+			)
+			return tcpAddr.String(), nil
+		}
+
+		lg.Warn(
+			"failed to resolve URL Host",
+			zap.String("url", u.String()),
+			zap.String("host", u.Host),
+			zap.Duration("retry-interval", retryInterval),
+			zap.Error(err),
+		)
+
+		select {
+		case <-ctx.Done():
+			lg.Warn(
+				"failed to resolve URL Host; returning",
+				zap.String("url", u.String()),
+				zap.String("host", u.Host),
+				zap.Duration("retry-interval", retryInterval),
+				zap.Error(err),
+			)
+			return "", err
+		case <-time.After(retryInterval):
+		}
+	}
+	return "", ctx.Err()
+}
+
+// urlsEqual checks equality of url.URLS between two arrays.
+// This check pass even if an URL is in hostname and opposite is in IP address.
+func urlsEqual(ctx context.Context, lg *zap.Logger, a []url.URL, b []url.URL) (bool, error) {
+	if len(a) != len(b) {
+		return false, fmt.Errorf("len(%q) != len(%q)", urlsToStrings(a), urlsToStrings(b))
+	}
+	urls, err := resolveTCPAddrs(ctx, lg, [][]url.URL{a, b})
+	if err != nil {
+		return false, err
+	}
+	preva, prevb := a, b
+	a, b = urls[0], urls[1]
+	sort.Sort(types.URLs(a))
+	sort.Sort(types.URLs(b))
+	for i := range a {
+		if !reflect.DeepEqual(a[i], b[i]) {
+			return false, fmt.Errorf("%q(resolved from %q) != %q(resolved from %q)",
+				a[i].String(), preva[i].String(),
+				b[i].String(), prevb[i].String(),
+			)
+		}
+	}
+	return true, nil
+}
+
+// URLStringsEqual returns "true" if given URLs are valid
+// and resolved to same IP addresses. Otherwise, return "false"
+// and error, if any.
+func URLStringsEqual(ctx context.Context, lg *zap.Logger, a []string, b []string) (bool, error) {
+	if len(a) != len(b) {
+		return false, fmt.Errorf("len(%q) != len(%q)", a, b)
+	}
+	urlsA := make([]url.URL, 0)
+	for _, str := range a {
+		u, err := url.Parse(str)
+		if err != nil {
+			return false, fmt.Errorf("failed to parse %q", str)
+		}
+		urlsA = append(urlsA, *u)
+	}
+	urlsB := make([]url.URL, 0)
+	for _, str := range b {
+		u, err := url.Parse(str)
+		if err != nil {
+			return false, fmt.Errorf("failed to parse %q", str)
+		}
+		urlsB = append(urlsB, *u)
+	}
+	if lg == nil {
+		lg, _ = zap.NewProduction()
+		if lg == nil {
+			lg = zap.NewExample()
+		}
+	}
+	return urlsEqual(ctx, lg, urlsA, urlsB)
+}
+
+func urlsToStrings(us []url.URL) []string {
+	rs := make([]string, len(us))
+	for i := range us {
+		rs[i] = us[i].String()
+	}
+	return rs
+}
+
+func IsNetworkTimeoutError(err error) bool {
+	nerr, ok := err.(net.Error)
+	return ok && nerr.Timeout()
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/routes.go b/vendor/go.etcd.io/etcd/pkg/netutil/routes.go
new file mode 100644
index 0000000..3eb6a19
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/routes.go
@@ -0,0 +1,33 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux
+
+package netutil
+
+import (
+	"fmt"
+	"runtime"
+)
+
+// GetDefaultHost fetches the a resolvable name that corresponds
+// to the machine's default routable interface
+func GetDefaultHost() (string, error) {
+	return "", fmt.Errorf("default host not supported on %s_%s", runtime.GOOS, runtime.GOARCH)
+}
+
+// GetDefaultInterfaces fetches the device name of default routable interface.
+func GetDefaultInterfaces() (map[string]uint8, error) {
+	return nil, fmt.Errorf("default host not supported on %s_%s", runtime.GOOS, runtime.GOARCH)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/netutil/routes_linux.go b/vendor/go.etcd.io/etcd/pkg/netutil/routes_linux.go
new file mode 100644
index 0000000..5118d3d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/netutil/routes_linux.go
@@ -0,0 +1,250 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build linux
+
+package netutil
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"net"
+	"sort"
+	"syscall"
+
+	"go.etcd.io/etcd/pkg/cpuutil"
+)
+
+var errNoDefaultRoute = fmt.Errorf("could not find default route")
+var errNoDefaultHost = fmt.Errorf("could not find default host")
+var errNoDefaultInterface = fmt.Errorf("could not find default interface")
+
+// GetDefaultHost obtains the first IP address of machine from the routing table and returns the IP address as string.
+// An IPv4 address is preferred to an IPv6 address for backward compatibility.
+func GetDefaultHost() (string, error) {
+	rmsgs, rerr := getDefaultRoutes()
+	if rerr != nil {
+		return "", rerr
+	}
+
+	// prioritize IPv4
+	if rmsg, ok := rmsgs[syscall.AF_INET]; ok {
+		if host, err := chooseHost(syscall.AF_INET, rmsg); host != "" || err != nil {
+			return host, err
+		}
+		delete(rmsgs, syscall.AF_INET)
+	}
+
+	// sort so choice is deterministic
+	var families []int
+	for family := range rmsgs {
+		families = append(families, int(family))
+	}
+	sort.Ints(families)
+
+	for _, f := range families {
+		family := uint8(f)
+		if host, err := chooseHost(family, rmsgs[family]); host != "" || err != nil {
+			return host, err
+		}
+	}
+
+	return "", errNoDefaultHost
+}
+
+func chooseHost(family uint8, rmsg *syscall.NetlinkMessage) (string, error) {
+	host, oif, err := parsePREFSRC(rmsg)
+	if host != "" || err != nil {
+		return host, err
+	}
+
+	// prefsrc not detected, fall back to getting address from iface
+	ifmsg, ierr := getIfaceAddr(oif, family)
+	if ierr != nil {
+		return "", ierr
+	}
+
+	attrs, aerr := syscall.ParseNetlinkRouteAttr(ifmsg)
+	if aerr != nil {
+		return "", aerr
+	}
+
+	for _, attr := range attrs {
+		// search for RTA_DST because ipv6 doesn't have RTA_SRC
+		if attr.Attr.Type == syscall.RTA_DST {
+			return net.IP(attr.Value).String(), nil
+		}
+	}
+
+	return "", nil
+}
+
+func getDefaultRoutes() (map[uint8]*syscall.NetlinkMessage, error) {
+	dat, err := syscall.NetlinkRIB(syscall.RTM_GETROUTE, syscall.AF_UNSPEC)
+	if err != nil {
+		return nil, err
+	}
+
+	msgs, msgErr := syscall.ParseNetlinkMessage(dat)
+	if msgErr != nil {
+		return nil, msgErr
+	}
+
+	routes := make(map[uint8]*syscall.NetlinkMessage)
+	rtmsg := syscall.RtMsg{}
+	for _, m := range msgs {
+		if m.Header.Type != syscall.RTM_NEWROUTE {
+			continue
+		}
+		buf := bytes.NewBuffer(m.Data[:syscall.SizeofRtMsg])
+		if rerr := binary.Read(buf, cpuutil.ByteOrder(), &rtmsg); rerr != nil {
+			continue
+		}
+		if rtmsg.Dst_len == 0 && rtmsg.Table == syscall.RT_TABLE_MAIN {
+			// zero-length Dst_len implies default route
+			msg := m
+			routes[rtmsg.Family] = &msg
+		}
+	}
+
+	if len(routes) > 0 {
+		return routes, nil
+	}
+
+	return nil, errNoDefaultRoute
+}
+
+// Used to get an address of interface.
+func getIfaceAddr(idx uint32, family uint8) (*syscall.NetlinkMessage, error) {
+	dat, err := syscall.NetlinkRIB(syscall.RTM_GETADDR, int(family))
+	if err != nil {
+		return nil, err
+	}
+
+	msgs, msgErr := syscall.ParseNetlinkMessage(dat)
+	if msgErr != nil {
+		return nil, msgErr
+	}
+
+	ifaddrmsg := syscall.IfAddrmsg{}
+	for _, m := range msgs {
+		if m.Header.Type != syscall.RTM_NEWADDR {
+			continue
+		}
+		buf := bytes.NewBuffer(m.Data[:syscall.SizeofIfAddrmsg])
+		if rerr := binary.Read(buf, cpuutil.ByteOrder(), &ifaddrmsg); rerr != nil {
+			continue
+		}
+		if ifaddrmsg.Index == idx {
+			return &m, nil
+		}
+	}
+
+	return nil, fmt.Errorf("could not find address for interface index %v", idx)
+
+}
+
+// Used to get a name of interface.
+func getIfaceLink(idx uint32) (*syscall.NetlinkMessage, error) {
+	dat, err := syscall.NetlinkRIB(syscall.RTM_GETLINK, syscall.AF_UNSPEC)
+	if err != nil {
+		return nil, err
+	}
+
+	msgs, msgErr := syscall.ParseNetlinkMessage(dat)
+	if msgErr != nil {
+		return nil, msgErr
+	}
+
+	ifinfomsg := syscall.IfInfomsg{}
+	for _, m := range msgs {
+		if m.Header.Type != syscall.RTM_NEWLINK {
+			continue
+		}
+		buf := bytes.NewBuffer(m.Data[:syscall.SizeofIfInfomsg])
+		if rerr := binary.Read(buf, cpuutil.ByteOrder(), &ifinfomsg); rerr != nil {
+			continue
+		}
+		if ifinfomsg.Index == int32(idx) {
+			return &m, nil
+		}
+	}
+
+	return nil, fmt.Errorf("could not find link for interface index %v", idx)
+}
+
+// GetDefaultInterfaces gets names of interfaces and returns a map[interface]families.
+func GetDefaultInterfaces() (map[string]uint8, error) {
+	interfaces := make(map[string]uint8)
+	rmsgs, rerr := getDefaultRoutes()
+	if rerr != nil {
+		return interfaces, rerr
+	}
+
+	for family, rmsg := range rmsgs {
+		_, oif, err := parsePREFSRC(rmsg)
+		if err != nil {
+			return interfaces, err
+		}
+
+		ifmsg, ierr := getIfaceLink(oif)
+		if ierr != nil {
+			return interfaces, ierr
+		}
+
+		attrs, aerr := syscall.ParseNetlinkRouteAttr(ifmsg)
+		if aerr != nil {
+			return interfaces, aerr
+		}
+
+		for _, attr := range attrs {
+			if attr.Attr.Type == syscall.IFLA_IFNAME {
+				// key is an interface name
+				// possible values: 2 - AF_INET, 10 - AF_INET6, 12 - dualstack
+				interfaces[string(attr.Value[:len(attr.Value)-1])] += family
+			}
+		}
+	}
+	if len(interfaces) > 0 {
+		return interfaces, nil
+	}
+	return interfaces, errNoDefaultInterface
+}
+
+// parsePREFSRC returns preferred source address and output interface index (RTA_OIF).
+func parsePREFSRC(m *syscall.NetlinkMessage) (host string, oif uint32, err error) {
+	var attrs []syscall.NetlinkRouteAttr
+	attrs, err = syscall.ParseNetlinkRouteAttr(m)
+	if err != nil {
+		return "", 0, err
+	}
+
+	for _, attr := range attrs {
+		if attr.Attr.Type == syscall.RTA_PREFSRC {
+			host = net.IP(attr.Value).String()
+		}
+		if attr.Attr.Type == syscall.RTA_OIF {
+			oif = cpuutil.ByteOrder().Uint32(attr.Value)
+		}
+		if host != "" && oif != uint32(0) {
+			break
+		}
+	}
+
+	if oif == 0 {
+		err = errNoDefaultRoute
+	}
+	return host, oif, err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/pathutil/path.go b/vendor/go.etcd.io/etcd/pkg/pathutil/path.go
new file mode 100644
index 0000000..f26254b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/pathutil/path.go
@@ -0,0 +1,31 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package pathutil implements utility functions for handling slash-separated
+// paths.
+package pathutil
+
+import "path"
+
+// CanonicalURLPath returns the canonical url path for p, which follows the rules:
+// 1. the path always starts with "/"
+// 2. replace multiple slashes with a single slash
+// 3. replace each '.' '..' path name element with equivalent one
+// 4. keep the trailing slash
+// The function is borrowed from stdlib http.cleanPath in server.go.
+func CanonicalURLPath(p string) string {
+	if p == "" {
+		return "/"
+	}
+	if p[0] != '/' {
+		p = "/" + p
+	}
+	np := path.Clean(p)
+	// path.Clean removes trailing slash except for root,
+	// put the trailing slash back if necessary.
+	if p[len(p)-1] == '/' && np != "/" {
+		np += "/"
+	}
+	return np
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/pbutil/pbutil.go b/vendor/go.etcd.io/etcd/pkg/pbutil/pbutil.go
new file mode 100644
index 0000000..53167ff
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/pbutil/pbutil.go
@@ -0,0 +1,60 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pbutil defines interfaces for handling Protocol Buffer objects.
+package pbutil
+
+import "github.com/coreos/pkg/capnslog"
+
+var (
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "pkg/pbutil")
+)
+
+type Marshaler interface {
+	Marshal() (data []byte, err error)
+}
+
+type Unmarshaler interface {
+	Unmarshal(data []byte) error
+}
+
+func MustMarshal(m Marshaler) []byte {
+	d, err := m.Marshal()
+	if err != nil {
+		plog.Panicf("marshal should never fail (%v)", err)
+	}
+	return d
+}
+
+func MustUnmarshal(um Unmarshaler, data []byte) {
+	if err := um.Unmarshal(data); err != nil {
+		plog.Panicf("unmarshal should never fail (%v)", err)
+	}
+}
+
+func MaybeUnmarshal(um Unmarshaler, data []byte) bool {
+	if err := um.Unmarshal(data); err != nil {
+		return false
+	}
+	return true
+}
+
+func GetBool(v *bool) (vv bool, set bool) {
+	if v == nil {
+		return false, false
+	}
+	return *v, true
+}
+
+func Boolp(b bool) *bool { return &b }
diff --git a/vendor/go.etcd.io/etcd/pkg/runtime/fds_linux.go b/vendor/go.etcd.io/etcd/pkg/runtime/fds_linux.go
new file mode 100644
index 0000000..8e9359d
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/runtime/fds_linux.go
@@ -0,0 +1,37 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package runtime implements utility functions for runtime systems.
+package runtime
+
+import (
+	"io/ioutil"
+	"syscall"
+)
+
+func FDLimit() (uint64, error) {
+	var rlimit syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit); err != nil {
+		return 0, err
+	}
+	return rlimit.Cur, nil
+}
+
+func FDUsage() (uint64, error) {
+	fds, err := ioutil.ReadDir("/proc/self/fd")
+	if err != nil {
+		return 0, err
+	}
+	return uint64(len(fds)), nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/runtime/fds_other.go b/vendor/go.etcd.io/etcd/pkg/runtime/fds_other.go
new file mode 100644
index 0000000..0cbdb88
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/runtime/fds_other.go
@@ -0,0 +1,30 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !linux
+
+package runtime
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func FDLimit() (uint64, error) {
+	return 0, fmt.Errorf("cannot get FDLimit on %s", runtime.GOOS)
+}
+
+func FDUsage() (uint64, error) {
+	return 0, fmt.Errorf("cannot get FDUsage on %s", runtime.GOOS)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/schedule/doc.go b/vendor/go.etcd.io/etcd/pkg/schedule/doc.go
new file mode 100644
index 0000000..cca2c75
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/schedule/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package schedule provides mechanisms and policies for scheduling units of work.
+package schedule
diff --git a/vendor/go.etcd.io/etcd/pkg/schedule/schedule.go b/vendor/go.etcd.io/etcd/pkg/schedule/schedule.go
new file mode 100644
index 0000000..234d019
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/schedule/schedule.go
@@ -0,0 +1,165 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package schedule
+
+import (
+	"context"
+	"sync"
+)
+
+type Job func(context.Context)
+
+// Scheduler can schedule jobs.
+type Scheduler interface {
+	// Schedule asks the scheduler to schedule a job defined by the given func.
+	// Schedule to a stopped scheduler might panic.
+	Schedule(j Job)
+
+	// Pending returns number of pending jobs
+	Pending() int
+
+	// Scheduled returns the number of scheduled jobs (excluding pending jobs)
+	Scheduled() int
+
+	// Finished returns the number of finished jobs
+	Finished() int
+
+	// WaitFinish waits until at least n job are finished and all pending jobs are finished.
+	WaitFinish(n int)
+
+	// Stop stops the scheduler.
+	Stop()
+}
+
+type fifo struct {
+	mu sync.Mutex
+
+	resume    chan struct{}
+	scheduled int
+	finished  int
+	pendings  []Job
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	finishCond *sync.Cond
+	donec      chan struct{}
+}
+
+// NewFIFOScheduler returns a Scheduler that schedules jobs in FIFO
+// order sequentially
+func NewFIFOScheduler() Scheduler {
+	f := &fifo{
+		resume: make(chan struct{}, 1),
+		donec:  make(chan struct{}, 1),
+	}
+	f.finishCond = sync.NewCond(&f.mu)
+	f.ctx, f.cancel = context.WithCancel(context.Background())
+	go f.run()
+	return f
+}
+
+// Schedule schedules a job that will be ran in FIFO order sequentially.
+func (f *fifo) Schedule(j Job) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	if f.cancel == nil {
+		panic("schedule: schedule to stopped scheduler")
+	}
+
+	if len(f.pendings) == 0 {
+		select {
+		case f.resume <- struct{}{}:
+		default:
+		}
+	}
+	f.pendings = append(f.pendings, j)
+}
+
+func (f *fifo) Pending() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.pendings)
+}
+
+func (f *fifo) Scheduled() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return f.scheduled
+}
+
+func (f *fifo) Finished() int {
+	f.finishCond.L.Lock()
+	defer f.finishCond.L.Unlock()
+	return f.finished
+}
+
+func (f *fifo) WaitFinish(n int) {
+	f.finishCond.L.Lock()
+	for f.finished < n || len(f.pendings) != 0 {
+		f.finishCond.Wait()
+	}
+	f.finishCond.L.Unlock()
+}
+
+// Stop stops the scheduler and cancels all pending jobs.
+func (f *fifo) Stop() {
+	f.mu.Lock()
+	f.cancel()
+	f.cancel = nil
+	f.mu.Unlock()
+	<-f.donec
+}
+
+func (f *fifo) run() {
+	// TODO: recover from job panic?
+	defer func() {
+		close(f.donec)
+		close(f.resume)
+	}()
+
+	for {
+		var todo Job
+		f.mu.Lock()
+		if len(f.pendings) != 0 {
+			f.scheduled++
+			todo = f.pendings[0]
+		}
+		f.mu.Unlock()
+		if todo == nil {
+			select {
+			case <-f.resume:
+			case <-f.ctx.Done():
+				f.mu.Lock()
+				pendings := f.pendings
+				f.pendings = nil
+				f.mu.Unlock()
+				// clean up pending jobs
+				for _, todo := range pendings {
+					todo(f.ctx)
+				}
+				return
+			}
+		} else {
+			todo(f.ctx)
+			f.finishCond.L.Lock()
+			f.finished++
+			f.pendings = f.pendings[1:]
+			f.finishCond.Broadcast()
+			f.finishCond.L.Unlock()
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/srv/srv.go b/vendor/go.etcd.io/etcd/pkg/srv/srv.go
new file mode 100644
index 0000000..c356002
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/srv/srv.go
@@ -0,0 +1,142 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package srv looks up DNS SRV records.
+package srv
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"strings"
+
+	"go.etcd.io/etcd/pkg/types"
+)
+
+var (
+	// indirection for testing
+	lookupSRV      = net.LookupSRV // net.DefaultResolver.LookupSRV when ctxs don't conflict
+	resolveTCPAddr = net.ResolveTCPAddr
+)
+
+// GetCluster gets the cluster information via DNS discovery.
+// Also sees each entry as a separate instance.
+func GetCluster(serviceScheme, service, name, dns string, apurls types.URLs) ([]string, error) {
+	tempName := int(0)
+	tcp2ap := make(map[string]url.URL)
+
+	// First, resolve the apurls
+	for _, url := range apurls {
+		tcpAddr, err := resolveTCPAddr("tcp", url.Host)
+		if err != nil {
+			return nil, err
+		}
+		tcp2ap[tcpAddr.String()] = url
+	}
+
+	stringParts := []string{}
+	updateNodeMap := func(service, scheme string) error {
+		_, addrs, err := lookupSRV(service, "tcp", dns)
+		if err != nil {
+			return err
+		}
+		for _, srv := range addrs {
+			port := fmt.Sprintf("%d", srv.Port)
+			host := net.JoinHostPort(srv.Target, port)
+			tcpAddr, terr := resolveTCPAddr("tcp", host)
+			if terr != nil {
+				err = terr
+				continue
+			}
+			n := ""
+			url, ok := tcp2ap[tcpAddr.String()]
+			if ok {
+				n = name
+			}
+			if n == "" {
+				n = fmt.Sprintf("%d", tempName)
+				tempName++
+			}
+			// SRV records have a trailing dot but URL shouldn't.
+			shortHost := strings.TrimSuffix(srv.Target, ".")
+			urlHost := net.JoinHostPort(shortHost, port)
+			if ok && url.Scheme != scheme {
+				err = fmt.Errorf("bootstrap at %s from DNS for %s has scheme mismatch with expected peer %s", scheme+"://"+urlHost, service, url.String())
+			} else {
+				stringParts = append(stringParts, fmt.Sprintf("%s=%s://%s", n, scheme, urlHost))
+			}
+		}
+		if len(stringParts) == 0 {
+			return err
+		}
+		return nil
+	}
+
+	err := updateNodeMap(service, serviceScheme)
+	if err != nil {
+		return nil, fmt.Errorf("error querying DNS SRV records for _%s %s", service, err)
+	}
+	return stringParts, nil
+}
+
+type SRVClients struct {
+	Endpoints []string
+	SRVs      []*net.SRV
+}
+
+// GetClient looks up the client endpoints for a service and domain.
+func GetClient(service, domain string, serviceName string) (*SRVClients, error) {
+	var urls []*url.URL
+	var srvs []*net.SRV
+
+	updateURLs := func(service, scheme string) error {
+		_, addrs, err := lookupSRV(service, "tcp", domain)
+		if err != nil {
+			return err
+		}
+		for _, srv := range addrs {
+			urls = append(urls, &url.URL{
+				Scheme: scheme,
+				Host:   net.JoinHostPort(srv.Target, fmt.Sprintf("%d", srv.Port)),
+			})
+		}
+		srvs = append(srvs, addrs...)
+		return nil
+	}
+
+	errHTTPS := updateURLs(GetSRVService(service, serviceName, "https"), "https")
+	errHTTP := updateURLs(GetSRVService(service, serviceName, "http"), "http")
+
+	if errHTTPS != nil && errHTTP != nil {
+		return nil, fmt.Errorf("dns lookup errors: %s and %s", errHTTPS, errHTTP)
+	}
+
+	endpoints := make([]string, len(urls))
+	for i := range urls {
+		endpoints[i] = urls[i].String()
+	}
+	return &SRVClients{Endpoints: endpoints, SRVs: srvs}, nil
+}
+
+// GetSRVService generates a SRV service including an optional suffix.
+func GetSRVService(service, serviceName string, scheme string) (SRVService string) {
+	if scheme == "https" {
+		service = fmt.Sprintf("%s-ssl", service)
+	}
+
+	if serviceName != "" {
+		return fmt.Sprintf("%s-%s", service, serviceName)
+	}
+	return service
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/tlsutil/cipher_suites.go b/vendor/go.etcd.io/etcd/pkg/tlsutil/cipher_suites.go
new file mode 100644
index 0000000..b5916bb
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/tlsutil/cipher_suites.go
@@ -0,0 +1,51 @@
+// Copyright 2018 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tlsutil
+
+import "crypto/tls"
+
+// cipher suites implemented by Go
+// https://github.com/golang/go/blob/dev.boringcrypto.go1.10/src/crypto/tls/cipher_suites.go
+var cipherSuites = map[string]uint16{
+	"TLS_RSA_WITH_RC4_128_SHA":                tls.TLS_RSA_WITH_RC4_128_SHA,
+	"TLS_RSA_WITH_3DES_EDE_CBC_SHA":           tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+	"TLS_RSA_WITH_AES_128_CBC_SHA":            tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+	"TLS_RSA_WITH_AES_256_CBC_SHA":            tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+	"TLS_RSA_WITH_AES_128_CBC_SHA256":         tls.TLS_RSA_WITH_AES_128_CBC_SHA256,
+	"TLS_RSA_WITH_AES_128_GCM_SHA256":         tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+	"TLS_RSA_WITH_AES_256_GCM_SHA384":         tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_ECDSA_WITH_RC4_128_SHA":        tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA":    tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA":    tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_RC4_128_SHA":          tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	"TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA":     tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA":      tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+	"TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA":      tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256": tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256":   tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256":   tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	"TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256": tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+	"TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384":   tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384": tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+	"TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305":    tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+	"TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305":  tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
+}
+
+// GetCipherSuite returns the corresponding cipher suite,
+// and boolean value if it is supported.
+func GetCipherSuite(s string) (uint16, bool) {
+	v, ok := cipherSuites[s]
+	return v, ok
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/tlsutil/doc.go b/vendor/go.etcd.io/etcd/pkg/tlsutil/doc.go
new file mode 100644
index 0000000..3b6aa67
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/tlsutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package tlsutil provides utility functions for handling TLS.
+package tlsutil
diff --git a/vendor/go.etcd.io/etcd/pkg/tlsutil/tlsutil.go b/vendor/go.etcd.io/etcd/pkg/tlsutil/tlsutil.go
new file mode 100644
index 0000000..3a5aef0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/tlsutil/tlsutil.go
@@ -0,0 +1,73 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tlsutil
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"io/ioutil"
+)
+
+// NewCertPool creates x509 certPool with provided CA files.
+func NewCertPool(CAFiles []string) (*x509.CertPool, error) {
+	certPool := x509.NewCertPool()
+
+	for _, CAFile := range CAFiles {
+		pemByte, err := ioutil.ReadFile(CAFile)
+		if err != nil {
+			return nil, err
+		}
+
+		for {
+			var block *pem.Block
+			block, pemByte = pem.Decode(pemByte)
+			if block == nil {
+				break
+			}
+			cert, err := x509.ParseCertificate(block.Bytes)
+			if err != nil {
+				return nil, err
+			}
+
+			certPool.AddCert(cert)
+		}
+	}
+
+	return certPool, nil
+}
+
+// NewCert generates TLS cert by using the given cert,key and parse function.
+func NewCert(certfile, keyfile string, parseFunc func([]byte, []byte) (tls.Certificate, error)) (*tls.Certificate, error) {
+	cert, err := ioutil.ReadFile(certfile)
+	if err != nil {
+		return nil, err
+	}
+
+	key, err := ioutil.ReadFile(keyfile)
+	if err != nil {
+		return nil, err
+	}
+
+	if parseFunc == nil {
+		parseFunc = tls.X509KeyPair
+	}
+
+	tlsCert, err := parseFunc(cert, key)
+	if err != nil {
+		return nil, err
+	}
+	return &tlsCert, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/doc.go b/vendor/go.etcd.io/etcd/pkg/transport/doc.go
new file mode 100644
index 0000000..37658ce
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/doc.go
@@ -0,0 +1,17 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package transport implements various HTTP transport utilities based on Go
+// net package.
+package transport
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/keepalive_listener.go b/vendor/go.etcd.io/etcd/pkg/transport/keepalive_listener.go
new file mode 100644
index 0000000..4ff8e7f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/keepalive_listener.go
@@ -0,0 +1,94 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net"
+	"time"
+)
+
+type keepAliveConn interface {
+	SetKeepAlive(bool) error
+	SetKeepAlivePeriod(d time.Duration) error
+}
+
+// NewKeepAliveListener returns a listener that listens on the given address.
+// Be careful when wrap around KeepAliveListener with another Listener if TLSInfo is not nil.
+// Some pkgs (like go/http) might expect Listener to return TLSConn type to start TLS handshake.
+// http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html
+func NewKeepAliveListener(l net.Listener, scheme string, tlscfg *tls.Config) (net.Listener, error) {
+	if scheme == "https" {
+		if tlscfg == nil {
+			return nil, fmt.Errorf("cannot listen on TLS for given listener: KeyFile and CertFile are not presented")
+		}
+		return newTLSKeepaliveListener(l, tlscfg), nil
+	}
+
+	return &keepaliveListener{
+		Listener: l,
+	}, nil
+}
+
+type keepaliveListener struct{ net.Listener }
+
+func (kln *keepaliveListener) Accept() (net.Conn, error) {
+	c, err := kln.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+	kac := c.(keepAliveConn)
+	// detection time: tcp_keepalive_time + tcp_keepalive_probes + tcp_keepalive_intvl
+	// default on linux:  30 + 8 * 30
+	// default on osx:    30 + 8 * 75
+	kac.SetKeepAlive(true)
+	kac.SetKeepAlivePeriod(30 * time.Second)
+	return c, nil
+}
+
+// A tlsKeepaliveListener implements a network listener (net.Listener) for TLS connections.
+type tlsKeepaliveListener struct {
+	net.Listener
+	config *tls.Config
+}
+
+// Accept waits for and returns the next incoming TLS connection.
+// The returned connection c is a *tls.Conn.
+func (l *tlsKeepaliveListener) Accept() (c net.Conn, err error) {
+	c, err = l.Listener.Accept()
+	if err != nil {
+		return
+	}
+	kac := c.(keepAliveConn)
+	// detection time: tcp_keepalive_time + tcp_keepalive_probes + tcp_keepalive_intvl
+	// default on linux:  30 + 8 * 30
+	// default on osx:    30 + 8 * 75
+	kac.SetKeepAlive(true)
+	kac.SetKeepAlivePeriod(30 * time.Second)
+	c = tls.Server(c, l.config)
+	return c, nil
+}
+
+// NewListener creates a Listener which accepts connections from an inner
+// Listener and wraps each connection with Server.
+// The configuration config must be non-nil and must have
+// at least one certificate.
+func newTLSKeepaliveListener(inner net.Listener, config *tls.Config) net.Listener {
+	l := &tlsKeepaliveListener{}
+	l.Listener = inner
+	l.config = config
+	return l
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/limit_listen.go b/vendor/go.etcd.io/etcd/pkg/transport/limit_listen.go
new file mode 100644
index 0000000..930c542
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/limit_listen.go
@@ -0,0 +1,80 @@
+// Copyright 2013 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package transport provides network utility functions, complementing the more
+// common ones in the net package.
+package transport
+
+import (
+	"errors"
+	"net"
+	"sync"
+	"time"
+)
+
+var (
+	ErrNotTCP = errors.New("only tcp connections have keepalive")
+)
+
+// LimitListener returns a Listener that accepts at most n simultaneous
+// connections from the provided Listener.
+func LimitListener(l net.Listener, n int) net.Listener {
+	return &limitListener{l, make(chan struct{}, n)}
+}
+
+type limitListener struct {
+	net.Listener
+	sem chan struct{}
+}
+
+func (l *limitListener) acquire() { l.sem <- struct{}{} }
+func (l *limitListener) release() { <-l.sem }
+
+func (l *limitListener) Accept() (net.Conn, error) {
+	l.acquire()
+	c, err := l.Listener.Accept()
+	if err != nil {
+		l.release()
+		return nil, err
+	}
+	return &limitListenerConn{Conn: c, release: l.release}, nil
+}
+
+type limitListenerConn struct {
+	net.Conn
+	releaseOnce sync.Once
+	release     func()
+}
+
+func (l *limitListenerConn) Close() error {
+	err := l.Conn.Close()
+	l.releaseOnce.Do(l.release)
+	return err
+}
+
+func (l *limitListenerConn) SetKeepAlive(doKeepAlive bool) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlive(doKeepAlive)
+}
+
+func (l *limitListenerConn) SetKeepAlivePeriod(d time.Duration) error {
+	tcpc, ok := l.Conn.(*net.TCPConn)
+	if !ok {
+		return ErrNotTCP
+	}
+	return tcpc.SetKeepAlivePeriod(d)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/listener.go b/vendor/go.etcd.io/etcd/pkg/transport/listener.go
new file mode 100644
index 0000000..fa12911
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/listener.go
@@ -0,0 +1,451 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"math/big"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"go.etcd.io/etcd/pkg/tlsutil"
+
+	"go.uber.org/zap"
+)
+
+// NewListener creates a new listner.
+func NewListener(addr, scheme string, tlsinfo *TLSInfo) (l net.Listener, err error) {
+	if l, err = newListener(addr, scheme); err != nil {
+		return nil, err
+	}
+	return wrapTLS(scheme, tlsinfo, l)
+}
+
+func newListener(addr string, scheme string) (net.Listener, error) {
+	if scheme == "unix" || scheme == "unixs" {
+		// unix sockets via unix://laddr
+		return NewUnixListener(addr)
+	}
+	return net.Listen("tcp", addr)
+}
+
+func wrapTLS(scheme string, tlsinfo *TLSInfo, l net.Listener) (net.Listener, error) {
+	if scheme != "https" && scheme != "unixs" {
+		return l, nil
+	}
+	if tlsinfo != nil && tlsinfo.SkipClientSANVerify {
+		return NewTLSListener(l, tlsinfo)
+	}
+	return newTLSListener(l, tlsinfo, checkSAN)
+}
+
+type TLSInfo struct {
+	CertFile            string
+	KeyFile             string
+	TrustedCAFile       string
+	ClientCertAuth      bool
+	CRLFile             string
+	InsecureSkipVerify  bool
+	SkipClientSANVerify bool
+
+	// ServerName ensures the cert matches the given host in case of discovery / virtual hosting
+	ServerName string
+
+	// HandshakeFailure is optionally called when a connection fails to handshake. The
+	// connection will be closed immediately afterwards.
+	HandshakeFailure func(*tls.Conn, error)
+
+	// CipherSuites is a list of supported cipher suites.
+	// If empty, Go auto-populates it by default.
+	// Note that cipher suites are prioritized in the given order.
+	CipherSuites []uint16
+
+	selfCert bool
+
+	// parseFunc exists to simplify testing. Typically, parseFunc
+	// should be left nil. In that case, tls.X509KeyPair will be used.
+	parseFunc func([]byte, []byte) (tls.Certificate, error)
+
+	// AllowedCN is a CN which must be provided by a client.
+	AllowedCN string
+
+	// AllowedHostname is an IP address or hostname that must match the TLS
+	// certificate provided by a client.
+	AllowedHostname string
+
+	// Logger logs TLS errors.
+	// If nil, all logs are discarded.
+	Logger *zap.Logger
+
+	// EmptyCN indicates that the cert must have empty CN.
+	// If true, ClientConfig() will return an error for a cert with non empty CN.
+	EmptyCN bool
+}
+
+func (info TLSInfo) String() string {
+	return fmt.Sprintf("cert = %s, key = %s, trusted-ca = %s, client-cert-auth = %v, crl-file = %s", info.CertFile, info.KeyFile, info.TrustedCAFile, info.ClientCertAuth, info.CRLFile)
+}
+
+func (info TLSInfo) Empty() bool {
+	return info.CertFile == "" && info.KeyFile == ""
+}
+
+func SelfCert(lg *zap.Logger, dirpath string, hosts []string, additionalUsages ...x509.ExtKeyUsage) (info TLSInfo, err error) {
+	if err = os.MkdirAll(dirpath, 0700); err != nil {
+		return
+	}
+	info.Logger = lg
+
+	certPath := filepath.Join(dirpath, "cert.pem")
+	keyPath := filepath.Join(dirpath, "key.pem")
+	_, errcert := os.Stat(certPath)
+	_, errkey := os.Stat(keyPath)
+	if errcert == nil && errkey == nil {
+		info.CertFile = certPath
+		info.KeyFile = keyPath
+		info.selfCert = true
+		return
+	}
+
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		if info.Logger != nil {
+			info.Logger.Warn(
+				"cannot generate random number",
+				zap.Error(err),
+			)
+		}
+		return
+	}
+
+	tmpl := x509.Certificate{
+		SerialNumber: serialNumber,
+		Subject:      pkix.Name{Organization: []string{"etcd"}},
+		NotBefore:    time.Now(),
+		NotAfter:     time.Now().Add(365 * (24 * time.Hour)),
+
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           append([]x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth}, additionalUsages...),
+		BasicConstraintsValid: true,
+	}
+
+	for _, host := range hosts {
+		h, _, _ := net.SplitHostPort(host)
+		if ip := net.ParseIP(h); ip != nil {
+			tmpl.IPAddresses = append(tmpl.IPAddresses, ip)
+		} else {
+			tmpl.DNSNames = append(tmpl.DNSNames, h)
+		}
+	}
+
+	priv, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
+	if err != nil {
+		if info.Logger != nil {
+			info.Logger.Warn(
+				"cannot generate ECDSA key",
+				zap.Error(err),
+			)
+		}
+		return
+	}
+
+	derBytes, err := x509.CreateCertificate(rand.Reader, &tmpl, &tmpl, &priv.PublicKey, priv)
+	if err != nil {
+		if info.Logger != nil {
+			info.Logger.Warn(
+				"cannot generate x509 certificate",
+				zap.Error(err),
+			)
+		}
+		return
+	}
+
+	certOut, err := os.Create(certPath)
+	if err != nil {
+		info.Logger.Warn(
+			"cannot cert file",
+			zap.String("path", certPath),
+			zap.Error(err),
+		)
+		return
+	}
+	pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	certOut.Close()
+	if info.Logger != nil {
+		info.Logger.Info("created cert file", zap.String("path", certPath))
+	}
+
+	b, err := x509.MarshalECPrivateKey(priv)
+	if err != nil {
+		return
+	}
+	keyOut, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		if info.Logger != nil {
+			info.Logger.Warn(
+				"cannot key file",
+				zap.String("path", keyPath),
+				zap.Error(err),
+			)
+		}
+		return
+	}
+	pem.Encode(keyOut, &pem.Block{Type: "EC PRIVATE KEY", Bytes: b})
+	keyOut.Close()
+	if info.Logger != nil {
+		info.Logger.Info("created key file", zap.String("path", keyPath))
+	}
+	return SelfCert(lg, dirpath, hosts)
+}
+
+// baseConfig is called on initial TLS handshake start.
+//
+// Previously,
+// 1. Server has non-empty (*tls.Config).Certificates on client hello
+// 2. Server calls (*tls.Config).GetCertificate iff:
+//    - Server's (*tls.Config).Certificates is not empty, or
+//    - Client supplies SNI; non-empty (*tls.ClientHelloInfo).ServerName
+//
+// When (*tls.Config).Certificates is always populated on initial handshake,
+// client is expected to provide a valid matching SNI to pass the TLS
+// verification, thus trigger server (*tls.Config).GetCertificate to reload
+// TLS assets. However, a cert whose SAN field does not include domain names
+// but only IP addresses, has empty (*tls.ClientHelloInfo).ServerName, thus
+// it was never able to trigger TLS reload on initial handshake; first
+// ceritifcate object was being used, never being updated.
+//
+// Now, (*tls.Config).Certificates is created empty on initial TLS client
+// handshake, in order to trigger (*tls.Config).GetCertificate and populate
+// rest of the certificates on every new TLS connection, even when client
+// SNI is empty (e.g. cert only includes IPs).
+func (info TLSInfo) baseConfig() (*tls.Config, error) {
+	if info.KeyFile == "" || info.CertFile == "" {
+		return nil, fmt.Errorf("KeyFile and CertFile must both be present[key: %v, cert: %v]", info.KeyFile, info.CertFile)
+	}
+	if info.Logger == nil {
+		info.Logger = zap.NewNop()
+	}
+
+	_, err := tlsutil.NewCert(info.CertFile, info.KeyFile, info.parseFunc)
+	if err != nil {
+		return nil, err
+	}
+
+	cfg := &tls.Config{
+		MinVersion: tls.VersionTLS12,
+		ServerName: info.ServerName,
+	}
+
+	if len(info.CipherSuites) > 0 {
+		cfg.CipherSuites = info.CipherSuites
+	}
+
+	// Client certificates may be verified by either an exact match on the CN,
+	// or a more general check of the CN and SANs.
+	var verifyCertificate func(*x509.Certificate) bool
+	if info.AllowedCN != "" {
+		if info.AllowedHostname != "" {
+			return nil, fmt.Errorf("AllowedCN and AllowedHostname are mutually exclusive (cn=%q, hostname=%q)", info.AllowedCN, info.AllowedHostname)
+		}
+		verifyCertificate = func(cert *x509.Certificate) bool {
+			return info.AllowedCN == cert.Subject.CommonName
+		}
+	}
+	if info.AllowedHostname != "" {
+		verifyCertificate = func(cert *x509.Certificate) bool {
+			return cert.VerifyHostname(info.AllowedHostname) == nil
+		}
+	}
+	if verifyCertificate != nil {
+		cfg.VerifyPeerCertificate = func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
+			for _, chains := range verifiedChains {
+				if len(chains) != 0 {
+					if verifyCertificate(chains[0]) {
+						return nil
+					}
+				}
+			}
+			return errors.New("client certificate authentication failed")
+		}
+	}
+
+	// this only reloads certs when there's a client request
+	// TODO: support server-side refresh (e.g. inotify, SIGHUP), caching
+	cfg.GetCertificate = func(clientHello *tls.ClientHelloInfo) (cert *tls.Certificate, err error) {
+		cert, err = tlsutil.NewCert(info.CertFile, info.KeyFile, info.parseFunc)
+		if os.IsNotExist(err) {
+			if info.Logger != nil {
+				info.Logger.Warn(
+					"failed to find peer cert files",
+					zap.String("cert-file", info.CertFile),
+					zap.String("key-file", info.KeyFile),
+					zap.Error(err),
+				)
+			}
+		} else if err != nil {
+			if info.Logger != nil {
+				info.Logger.Warn(
+					"failed to create peer certificate",
+					zap.String("cert-file", info.CertFile),
+					zap.String("key-file", info.KeyFile),
+					zap.Error(err),
+				)
+			}
+		}
+		return cert, err
+	}
+	cfg.GetClientCertificate = func(unused *tls.CertificateRequestInfo) (cert *tls.Certificate, err error) {
+		cert, err = tlsutil.NewCert(info.CertFile, info.KeyFile, info.parseFunc)
+		if os.IsNotExist(err) {
+			if info.Logger != nil {
+				info.Logger.Warn(
+					"failed to find client cert files",
+					zap.String("cert-file", info.CertFile),
+					zap.String("key-file", info.KeyFile),
+					zap.Error(err),
+				)
+			}
+		} else if err != nil {
+			if info.Logger != nil {
+				info.Logger.Warn(
+					"failed to create client certificate",
+					zap.String("cert-file", info.CertFile),
+					zap.String("key-file", info.KeyFile),
+					zap.Error(err),
+				)
+			}
+		}
+		return cert, err
+	}
+	return cfg, nil
+}
+
+// cafiles returns a list of CA file paths.
+func (info TLSInfo) cafiles() []string {
+	cs := make([]string, 0)
+	if info.TrustedCAFile != "" {
+		cs = append(cs, info.TrustedCAFile)
+	}
+	return cs
+}
+
+// ServerConfig generates a tls.Config object for use by an HTTP server.
+func (info TLSInfo) ServerConfig() (*tls.Config, error) {
+	cfg, err := info.baseConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	cfg.ClientAuth = tls.NoClientCert
+	if info.TrustedCAFile != "" || info.ClientCertAuth {
+		cfg.ClientAuth = tls.RequireAndVerifyClientCert
+	}
+
+	cs := info.cafiles()
+	if len(cs) > 0 {
+		cp, err := tlsutil.NewCertPool(cs)
+		if err != nil {
+			return nil, err
+		}
+		cfg.ClientCAs = cp
+	}
+
+	// "h2" NextProtos is necessary for enabling HTTP2 for go's HTTP server
+	cfg.NextProtos = []string{"h2"}
+
+	// go1.13 enables TLS 1.3 by default
+	// and in TLS 1.3, cipher suites are not configurable
+	// setting Max TLS version to TLS 1.2 for go 1.13
+	cfg.MaxVersion = tls.VersionTLS12
+
+	return cfg, nil
+}
+
+// ClientConfig generates a tls.Config object for use by an HTTP client.
+func (info TLSInfo) ClientConfig() (*tls.Config, error) {
+	var cfg *tls.Config
+	var err error
+
+	if !info.Empty() {
+		cfg, err = info.baseConfig()
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		cfg = &tls.Config{ServerName: info.ServerName}
+	}
+	cfg.InsecureSkipVerify = info.InsecureSkipVerify
+
+	cs := info.cafiles()
+	if len(cs) > 0 {
+		cfg.RootCAs, err = tlsutil.NewCertPool(cs)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if info.selfCert {
+		cfg.InsecureSkipVerify = true
+	}
+
+	if info.EmptyCN {
+		hasNonEmptyCN := false
+		cn := ""
+		tlsutil.NewCert(info.CertFile, info.KeyFile, func(certPEMBlock []byte, keyPEMBlock []byte) (tls.Certificate, error) {
+			var block *pem.Block
+			block, _ = pem.Decode(certPEMBlock)
+			cert, err := x509.ParseCertificate(block.Bytes)
+			if err != nil {
+				return tls.Certificate{}, err
+			}
+			if len(cert.Subject.CommonName) != 0 {
+				hasNonEmptyCN = true
+				cn = cert.Subject.CommonName
+			}
+			return tls.X509KeyPair(certPEMBlock, keyPEMBlock)
+		})
+		if hasNonEmptyCN {
+			return nil, fmt.Errorf("cert has non empty Common Name (%s)", cn)
+		}
+	}
+
+	// go1.13 enables TLS 1.3 by default
+	// and in TLS 1.3, cipher suites are not configurable
+	// setting Max TLS version to TLS 1.2 for go 1.13
+	cfg.MaxVersion = tls.VersionTLS12
+
+	return cfg, nil
+}
+
+// IsClosedConnError returns true if the error is from closing listener, cmux.
+// copied from golang.org/x/net/http2/http2.go
+func IsClosedConnError(err error) bool {
+	// 'use of closed network connection' (Go <=1.8)
+	// 'use of closed file or network connection' (Go >1.8, internal/poll.ErrClosing)
+	// 'mux: listener closed' (cmux.ErrListenerClosed)
+	return err != nil && strings.Contains(err.Error(), "closed")
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/listener_tls.go b/vendor/go.etcd.io/etcd/pkg/transport/listener_tls.go
new file mode 100644
index 0000000..6f16009
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/listener_tls.go
@@ -0,0 +1,272 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"strings"
+	"sync"
+)
+
+// tlsListener overrides a TLS listener so it will reject client
+// certificates with insufficient SAN credentials or CRL revoked
+// certificates.
+type tlsListener struct {
+	net.Listener
+	connc            chan net.Conn
+	donec            chan struct{}
+	err              error
+	handshakeFailure func(*tls.Conn, error)
+	check            tlsCheckFunc
+}
+
+type tlsCheckFunc func(context.Context, *tls.Conn) error
+
+// NewTLSListener handshakes TLS connections and performs optional CRL checking.
+func NewTLSListener(l net.Listener, tlsinfo *TLSInfo) (net.Listener, error) {
+	check := func(context.Context, *tls.Conn) error { return nil }
+	return newTLSListener(l, tlsinfo, check)
+}
+
+func newTLSListener(l net.Listener, tlsinfo *TLSInfo, check tlsCheckFunc) (net.Listener, error) {
+	if tlsinfo == nil || tlsinfo.Empty() {
+		l.Close()
+		return nil, fmt.Errorf("cannot listen on TLS for %s: KeyFile and CertFile are not presented", l.Addr().String())
+	}
+	tlscfg, err := tlsinfo.ServerConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	hf := tlsinfo.HandshakeFailure
+	if hf == nil {
+		hf = func(*tls.Conn, error) {}
+	}
+
+	if len(tlsinfo.CRLFile) > 0 {
+		prevCheck := check
+		check = func(ctx context.Context, tlsConn *tls.Conn) error {
+			if err := prevCheck(ctx, tlsConn); err != nil {
+				return err
+			}
+			st := tlsConn.ConnectionState()
+			if certs := st.PeerCertificates; len(certs) > 0 {
+				return checkCRL(tlsinfo.CRLFile, certs)
+			}
+			return nil
+		}
+	}
+
+	tlsl := &tlsListener{
+		Listener:         tls.NewListener(l, tlscfg),
+		connc:            make(chan net.Conn),
+		donec:            make(chan struct{}),
+		handshakeFailure: hf,
+		check:            check,
+	}
+	go tlsl.acceptLoop()
+	return tlsl, nil
+}
+
+func (l *tlsListener) Accept() (net.Conn, error) {
+	select {
+	case conn := <-l.connc:
+		return conn, nil
+	case <-l.donec:
+		return nil, l.err
+	}
+}
+
+func checkSAN(ctx context.Context, tlsConn *tls.Conn) error {
+	st := tlsConn.ConnectionState()
+	if certs := st.PeerCertificates; len(certs) > 0 {
+		addr := tlsConn.RemoteAddr().String()
+		return checkCertSAN(ctx, certs[0], addr)
+	}
+	return nil
+}
+
+// acceptLoop launches each TLS handshake in a separate goroutine
+// to prevent a hanging TLS connection from blocking other connections.
+func (l *tlsListener) acceptLoop() {
+	var wg sync.WaitGroup
+	var pendingMu sync.Mutex
+
+	pending := make(map[net.Conn]struct{})
+	ctx, cancel := context.WithCancel(context.Background())
+	defer func() {
+		cancel()
+		pendingMu.Lock()
+		for c := range pending {
+			c.Close()
+		}
+		pendingMu.Unlock()
+		wg.Wait()
+		close(l.donec)
+	}()
+
+	for {
+		conn, err := l.Listener.Accept()
+		if err != nil {
+			l.err = err
+			return
+		}
+
+		pendingMu.Lock()
+		pending[conn] = struct{}{}
+		pendingMu.Unlock()
+
+		wg.Add(1)
+		go func() {
+			defer func() {
+				if conn != nil {
+					conn.Close()
+				}
+				wg.Done()
+			}()
+
+			tlsConn := conn.(*tls.Conn)
+			herr := tlsConn.Handshake()
+			pendingMu.Lock()
+			delete(pending, conn)
+			pendingMu.Unlock()
+
+			if herr != nil {
+				l.handshakeFailure(tlsConn, herr)
+				return
+			}
+			if err := l.check(ctx, tlsConn); err != nil {
+				l.handshakeFailure(tlsConn, err)
+				return
+			}
+
+			select {
+			case l.connc <- tlsConn:
+				conn = nil
+			case <-ctx.Done():
+			}
+		}()
+	}
+}
+
+func checkCRL(crlPath string, cert []*x509.Certificate) error {
+	// TODO: cache
+	crlBytes, err := ioutil.ReadFile(crlPath)
+	if err != nil {
+		return err
+	}
+	certList, err := x509.ParseCRL(crlBytes)
+	if err != nil {
+		return err
+	}
+	revokedSerials := make(map[string]struct{})
+	for _, rc := range certList.TBSCertList.RevokedCertificates {
+		revokedSerials[string(rc.SerialNumber.Bytes())] = struct{}{}
+	}
+	for _, c := range cert {
+		serial := string(c.SerialNumber.Bytes())
+		if _, ok := revokedSerials[serial]; ok {
+			return fmt.Errorf("transport: certificate serial %x revoked", serial)
+		}
+	}
+	return nil
+}
+
+func checkCertSAN(ctx context.Context, cert *x509.Certificate, remoteAddr string) error {
+	if len(cert.IPAddresses) == 0 && len(cert.DNSNames) == 0 {
+		return nil
+	}
+	h, _, herr := net.SplitHostPort(remoteAddr)
+	if herr != nil {
+		return herr
+	}
+	if len(cert.IPAddresses) > 0 {
+		cerr := cert.VerifyHostname(h)
+		if cerr == nil {
+			return nil
+		}
+		if len(cert.DNSNames) == 0 {
+			return cerr
+		}
+	}
+	if len(cert.DNSNames) > 0 {
+		ok, err := isHostInDNS(ctx, h, cert.DNSNames)
+		if ok {
+			return nil
+		}
+		errStr := ""
+		if err != nil {
+			errStr = " (" + err.Error() + ")"
+		}
+		return fmt.Errorf("tls: %q does not match any of DNSNames %q"+errStr, h, cert.DNSNames)
+	}
+	return nil
+}
+
+func isHostInDNS(ctx context.Context, host string, dnsNames []string) (ok bool, err error) {
+	// reverse lookup
+	wildcards, names := []string{}, []string{}
+	for _, dns := range dnsNames {
+		if strings.HasPrefix(dns, "*.") {
+			wildcards = append(wildcards, dns[1:])
+		} else {
+			names = append(names, dns)
+		}
+	}
+	lnames, lerr := net.DefaultResolver.LookupAddr(ctx, host)
+	for _, name := range lnames {
+		// strip trailing '.' from PTR record
+		if name[len(name)-1] == '.' {
+			name = name[:len(name)-1]
+		}
+		for _, wc := range wildcards {
+			if strings.HasSuffix(name, wc) {
+				return true, nil
+			}
+		}
+		for _, n := range names {
+			if n == name {
+				return true, nil
+			}
+		}
+	}
+	err = lerr
+
+	// forward lookup
+	for _, dns := range names {
+		addrs, lerr := net.DefaultResolver.LookupHost(ctx, dns)
+		if lerr != nil {
+			err = lerr
+			continue
+		}
+		for _, addr := range addrs {
+			if addr == host {
+				return true, nil
+			}
+		}
+	}
+	return false, err
+}
+
+func (l *tlsListener) Close() error {
+	err := l.Listener.Close()
+	<-l.donec
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/timeout_conn.go b/vendor/go.etcd.io/etcd/pkg/transport/timeout_conn.go
new file mode 100644
index 0000000..7e8c020
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/timeout_conn.go
@@ -0,0 +1,44 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"time"
+)
+
+type timeoutConn struct {
+	net.Conn
+	wtimeoutd  time.Duration
+	rdtimeoutd time.Duration
+}
+
+func (c timeoutConn) Write(b []byte) (n int, err error) {
+	if c.wtimeoutd > 0 {
+		if err := c.SetWriteDeadline(time.Now().Add(c.wtimeoutd)); err != nil {
+			return 0, err
+		}
+	}
+	return c.Conn.Write(b)
+}
+
+func (c timeoutConn) Read(b []byte) (n int, err error) {
+	if c.rdtimeoutd > 0 {
+		if err := c.SetReadDeadline(time.Now().Add(c.rdtimeoutd)); err != nil {
+			return 0, err
+		}
+	}
+	return c.Conn.Read(b)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/timeout_dialer.go b/vendor/go.etcd.io/etcd/pkg/transport/timeout_dialer.go
new file mode 100644
index 0000000..6ae39ec
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/timeout_dialer.go
@@ -0,0 +1,36 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"time"
+)
+
+type rwTimeoutDialer struct {
+	wtimeoutd  time.Duration
+	rdtimeoutd time.Duration
+	net.Dialer
+}
+
+func (d *rwTimeoutDialer) Dial(network, address string) (net.Conn, error) {
+	conn, err := d.Dialer.Dial(network, address)
+	tconn := &timeoutConn{
+		rdtimeoutd: d.rdtimeoutd,
+		wtimeoutd:  d.wtimeoutd,
+		Conn:       conn,
+	}
+	return tconn, err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/timeout_listener.go b/vendor/go.etcd.io/etcd/pkg/transport/timeout_listener.go
new file mode 100644
index 0000000..273e99f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/timeout_listener.go
@@ -0,0 +1,57 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"time"
+)
+
+// NewTimeoutListener returns a listener that listens on the given address.
+// If read/write on the accepted connection blocks longer than its time limit,
+// it will return timeout error.
+func NewTimeoutListener(addr string, scheme string, tlsinfo *TLSInfo, rdtimeoutd, wtimeoutd time.Duration) (net.Listener, error) {
+	ln, err := newListener(addr, scheme)
+	if err != nil {
+		return nil, err
+	}
+	ln = &rwTimeoutListener{
+		Listener:   ln,
+		rdtimeoutd: rdtimeoutd,
+		wtimeoutd:  wtimeoutd,
+	}
+	if ln, err = wrapTLS(scheme, tlsinfo, ln); err != nil {
+		return nil, err
+	}
+	return ln, nil
+}
+
+type rwTimeoutListener struct {
+	net.Listener
+	wtimeoutd  time.Duration
+	rdtimeoutd time.Duration
+}
+
+func (rwln *rwTimeoutListener) Accept() (net.Conn, error) {
+	c, err := rwln.Listener.Accept()
+	if err != nil {
+		return nil, err
+	}
+	return timeoutConn{
+		Conn:       c,
+		wtimeoutd:  rwln.wtimeoutd,
+		rdtimeoutd: rwln.rdtimeoutd,
+	}, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/timeout_transport.go b/vendor/go.etcd.io/etcd/pkg/transport/timeout_transport.go
new file mode 100644
index 0000000..ea16b4c
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/timeout_transport.go
@@ -0,0 +1,51 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"net/http"
+	"time"
+)
+
+// NewTimeoutTransport returns a transport created using the given TLS info.
+// If read/write on the created connection blocks longer than its time limit,
+// it will return timeout error.
+// If read/write timeout is set, transport will not be able to reuse connection.
+func NewTimeoutTransport(info TLSInfo, dialtimeoutd, rdtimeoutd, wtimeoutd time.Duration) (*http.Transport, error) {
+	tr, err := NewTransport(info, dialtimeoutd)
+	if err != nil {
+		return nil, err
+	}
+
+	if rdtimeoutd != 0 || wtimeoutd != 0 {
+		// the timed out connection will timeout soon after it is idle.
+		// it should not be put back to http transport as an idle connection for future usage.
+		tr.MaxIdleConnsPerHost = -1
+	} else {
+		// allow more idle connections between peers to avoid unnecessary port allocation.
+		tr.MaxIdleConnsPerHost = 1024
+	}
+
+	tr.Dial = (&rwTimeoutDialer{
+		Dialer: net.Dialer{
+			Timeout:   dialtimeoutd,
+			KeepAlive: 30 * time.Second,
+		},
+		rdtimeoutd: rdtimeoutd,
+		wtimeoutd:  wtimeoutd,
+	}).Dial
+	return tr, nil
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/tls.go b/vendor/go.etcd.io/etcd/pkg/transport/tls.go
new file mode 100644
index 0000000..62fe0d3
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/tls.go
@@ -0,0 +1,49 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// ValidateSecureEndpoints scans the given endpoints against tls info, returning only those
+// endpoints that could be validated as secure.
+func ValidateSecureEndpoints(tlsInfo TLSInfo, eps []string) ([]string, error) {
+	t, err := NewTransport(tlsInfo, 5*time.Second)
+	if err != nil {
+		return nil, err
+	}
+	var errs []string
+	var endpoints []string
+	for _, ep := range eps {
+		if !strings.HasPrefix(ep, "https://") {
+			errs = append(errs, fmt.Sprintf("%q is insecure", ep))
+			continue
+		}
+		conn, cerr := t.Dial("tcp", ep[len("https://"):])
+		if cerr != nil {
+			errs = append(errs, fmt.Sprintf("%q failed to dial (%v)", ep, cerr))
+			continue
+		}
+		conn.Close()
+		endpoints = append(endpoints, ep)
+	}
+	if len(errs) != 0 {
+		err = fmt.Errorf("%s", strings.Join(errs, ","))
+	}
+	return endpoints, err
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/transport.go b/vendor/go.etcd.io/etcd/pkg/transport/transport.go
new file mode 100644
index 0000000..4a7fe69
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/transport.go
@@ -0,0 +1,71 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type unixTransport struct{ *http.Transport }
+
+func NewTransport(info TLSInfo, dialtimeoutd time.Duration) (*http.Transport, error) {
+	cfg, err := info.ClientConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	t := &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		Dial: (&net.Dialer{
+			Timeout: dialtimeoutd,
+			// value taken from http.DefaultTransport
+			KeepAlive: 30 * time.Second,
+		}).Dial,
+		// value taken from http.DefaultTransport
+		TLSHandshakeTimeout: 10 * time.Second,
+		TLSClientConfig:     cfg,
+	}
+
+	dialer := (&net.Dialer{
+		Timeout:   dialtimeoutd,
+		KeepAlive: 30 * time.Second,
+	})
+	dial := func(net, addr string) (net.Conn, error) {
+		return dialer.Dial("unix", addr)
+	}
+
+	tu := &http.Transport{
+		Proxy:               http.ProxyFromEnvironment,
+		Dial:                dial,
+		TLSHandshakeTimeout: 10 * time.Second,
+		TLSClientConfig:     cfg,
+	}
+	ut := &unixTransport{tu}
+
+	t.RegisterProtocol("unix", ut)
+	t.RegisterProtocol("unixs", ut)
+
+	return t, nil
+}
+
+func (urt *unixTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	url := *req.URL
+	req.URL = &url
+	req.URL.Scheme = strings.Replace(req.URL.Scheme, "unix", "http", 1)
+	return urt.Transport.RoundTrip(req)
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/transport/unix_listener.go b/vendor/go.etcd.io/etcd/pkg/transport/unix_listener.go
new file mode 100644
index 0000000..123e203
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/transport/unix_listener.go
@@ -0,0 +1,40 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package transport
+
+import (
+	"net"
+	"os"
+)
+
+type unixListener struct{ net.Listener }
+
+func NewUnixListener(addr string) (net.Listener, error) {
+	if err := os.Remove(addr); err != nil && !os.IsNotExist(err) {
+		return nil, err
+	}
+	l, err := net.Listen("unix", addr)
+	if err != nil {
+		return nil, err
+	}
+	return &unixListener{l}, nil
+}
+
+func (ul *unixListener) Close() error {
+	if err := os.Remove(ul.Addr().String()); err != nil && !os.IsNotExist(err) {
+		return err
+	}
+	return ul.Listener.Close()
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/wait/wait.go b/vendor/go.etcd.io/etcd/pkg/wait/wait.go
new file mode 100644
index 0000000..9b1df41
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/wait/wait.go
@@ -0,0 +1,91 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package wait provides utility functions for polling, listening using Go
+// channel.
+package wait
+
+import (
+	"log"
+	"sync"
+)
+
+// Wait is an interface that provides the ability to wait and trigger events that
+// are associated with IDs.
+type Wait interface {
+	// Register waits returns a chan that waits on the given ID.
+	// The chan will be triggered when Trigger is called with
+	// the same ID.
+	Register(id uint64) <-chan interface{}
+	// Trigger triggers the waiting chans with the given ID.
+	Trigger(id uint64, x interface{})
+	IsRegistered(id uint64) bool
+}
+
+type list struct {
+	l sync.RWMutex
+	m map[uint64]chan interface{}
+}
+
+// New creates a Wait.
+func New() Wait {
+	return &list{m: make(map[uint64]chan interface{})}
+}
+
+func (w *list) Register(id uint64) <-chan interface{} {
+	w.l.Lock()
+	defer w.l.Unlock()
+	ch := w.m[id]
+	if ch == nil {
+		ch = make(chan interface{}, 1)
+		w.m[id] = ch
+	} else {
+		log.Panicf("dup id %x", id)
+	}
+	return ch
+}
+
+func (w *list) Trigger(id uint64, x interface{}) {
+	w.l.Lock()
+	ch := w.m[id]
+	delete(w.m, id)
+	w.l.Unlock()
+	if ch != nil {
+		ch <- x
+		close(ch)
+	}
+}
+
+func (w *list) IsRegistered(id uint64) bool {
+	w.l.RLock()
+	defer w.l.RUnlock()
+	_, ok := w.m[id]
+	return ok
+}
+
+type waitWithResponse struct {
+	ch <-chan interface{}
+}
+
+func NewWithResponse(ch <-chan interface{}) Wait {
+	return &waitWithResponse{ch: ch}
+}
+
+func (w *waitWithResponse) Register(id uint64) <-chan interface{} {
+	return w.ch
+}
+func (w *waitWithResponse) Trigger(id uint64, x interface{}) {}
+func (w *waitWithResponse) IsRegistered(id uint64) bool {
+	panic("waitWithResponse.IsRegistered() shouldn't be called")
+}
diff --git a/vendor/go.etcd.io/etcd/pkg/wait/wait_time.go b/vendor/go.etcd.io/etcd/pkg/wait/wait_time.go
new file mode 100644
index 0000000..297e48a
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/wait/wait_time.go
@@ -0,0 +1,66 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wait
+
+import "sync"
+
+type WaitTime interface {
+	// Wait returns a chan that waits on the given logical deadline.
+	// The chan will be triggered when Trigger is called with a
+	// deadline that is later than the one it is waiting for.
+	Wait(deadline uint64) <-chan struct{}
+	// Trigger triggers all the waiting chans with an earlier logical deadline.
+	Trigger(deadline uint64)
+}
+
+var closec chan struct{}
+
+func init() { closec = make(chan struct{}); close(closec) }
+
+type timeList struct {
+	l                   sync.Mutex
+	lastTriggerDeadline uint64
+	m                   map[uint64]chan struct{}
+}
+
+func NewTimeList() *timeList {
+	return &timeList{m: make(map[uint64]chan struct{})}
+}
+
+func (tl *timeList) Wait(deadline uint64) <-chan struct{} {
+	tl.l.Lock()
+	defer tl.l.Unlock()
+	if tl.lastTriggerDeadline >= deadline {
+		return closec
+	}
+	ch := tl.m[deadline]
+	if ch == nil {
+		ch = make(chan struct{})
+		tl.m[deadline] = ch
+	}
+	return ch
+}
+
+func (tl *timeList) Trigger(deadline uint64) {
+	tl.l.Lock()
+	defer tl.l.Unlock()
+	tl.lastTriggerDeadline = deadline
+	for t, ch := range tl.m {
+		if t <= deadline {
+			delete(tl.m, t)
+			close(ch)
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/auth_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/auth_client_adapter.go
new file mode 100644
index 0000000..59dbe6b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/auth_client_adapter.go
@@ -0,0 +1,93 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	grpc "google.golang.org/grpc"
+)
+
+type as2ac struct{ as pb.AuthServer }
+
+func AuthServerToAuthClient(as pb.AuthServer) pb.AuthClient {
+	return &as2ac{as}
+}
+
+func (s *as2ac) AuthEnable(ctx context.Context, in *pb.AuthEnableRequest, opts ...grpc.CallOption) (*pb.AuthEnableResponse, error) {
+	return s.as.AuthEnable(ctx, in)
+}
+
+func (s *as2ac) AuthDisable(ctx context.Context, in *pb.AuthDisableRequest, opts ...grpc.CallOption) (*pb.AuthDisableResponse, error) {
+	return s.as.AuthDisable(ctx, in)
+}
+
+func (s *as2ac) Authenticate(ctx context.Context, in *pb.AuthenticateRequest, opts ...grpc.CallOption) (*pb.AuthenticateResponse, error) {
+	return s.as.Authenticate(ctx, in)
+}
+
+func (s *as2ac) RoleAdd(ctx context.Context, in *pb.AuthRoleAddRequest, opts ...grpc.CallOption) (*pb.AuthRoleAddResponse, error) {
+	return s.as.RoleAdd(ctx, in)
+}
+
+func (s *as2ac) RoleDelete(ctx context.Context, in *pb.AuthRoleDeleteRequest, opts ...grpc.CallOption) (*pb.AuthRoleDeleteResponse, error) {
+	return s.as.RoleDelete(ctx, in)
+}
+
+func (s *as2ac) RoleGet(ctx context.Context, in *pb.AuthRoleGetRequest, opts ...grpc.CallOption) (*pb.AuthRoleGetResponse, error) {
+	return s.as.RoleGet(ctx, in)
+}
+
+func (s *as2ac) RoleList(ctx context.Context, in *pb.AuthRoleListRequest, opts ...grpc.CallOption) (*pb.AuthRoleListResponse, error) {
+	return s.as.RoleList(ctx, in)
+}
+
+func (s *as2ac) RoleRevokePermission(ctx context.Context, in *pb.AuthRoleRevokePermissionRequest, opts ...grpc.CallOption) (*pb.AuthRoleRevokePermissionResponse, error) {
+	return s.as.RoleRevokePermission(ctx, in)
+}
+
+func (s *as2ac) RoleGrantPermission(ctx context.Context, in *pb.AuthRoleGrantPermissionRequest, opts ...grpc.CallOption) (*pb.AuthRoleGrantPermissionResponse, error) {
+	return s.as.RoleGrantPermission(ctx, in)
+}
+
+func (s *as2ac) UserDelete(ctx context.Context, in *pb.AuthUserDeleteRequest, opts ...grpc.CallOption) (*pb.AuthUserDeleteResponse, error) {
+	return s.as.UserDelete(ctx, in)
+}
+
+func (s *as2ac) UserAdd(ctx context.Context, in *pb.AuthUserAddRequest, opts ...grpc.CallOption) (*pb.AuthUserAddResponse, error) {
+	return s.as.UserAdd(ctx, in)
+}
+
+func (s *as2ac) UserGet(ctx context.Context, in *pb.AuthUserGetRequest, opts ...grpc.CallOption) (*pb.AuthUserGetResponse, error) {
+	return s.as.UserGet(ctx, in)
+}
+
+func (s *as2ac) UserList(ctx context.Context, in *pb.AuthUserListRequest, opts ...grpc.CallOption) (*pb.AuthUserListResponse, error) {
+	return s.as.UserList(ctx, in)
+}
+
+func (s *as2ac) UserGrantRole(ctx context.Context, in *pb.AuthUserGrantRoleRequest, opts ...grpc.CallOption) (*pb.AuthUserGrantRoleResponse, error) {
+	return s.as.UserGrantRole(ctx, in)
+}
+
+func (s *as2ac) UserRevokeRole(ctx context.Context, in *pb.AuthUserRevokeRoleRequest, opts ...grpc.CallOption) (*pb.AuthUserRevokeRoleResponse, error) {
+	return s.as.UserRevokeRole(ctx, in)
+}
+
+func (s *as2ac) UserChangePassword(ctx context.Context, in *pb.AuthUserChangePasswordRequest, opts ...grpc.CallOption) (*pb.AuthUserChangePasswordResponse, error) {
+	return s.as.UserChangePassword(ctx, in)
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/chan_stream.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/chan_stream.go
new file mode 100644
index 0000000..1af514b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/chan_stream.go
@@ -0,0 +1,167 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// chanServerStream implements grpc.ServerStream with a chanStream
+type chanServerStream struct {
+	headerc  chan<- metadata.MD
+	trailerc chan<- metadata.MD
+	grpc.Stream
+
+	headers []metadata.MD
+}
+
+func (ss *chanServerStream) SendHeader(md metadata.MD) error {
+	if ss.headerc == nil {
+		return errAlreadySentHeader
+	}
+	outmd := make(map[string][]string)
+	for _, h := range append(ss.headers, md) {
+		for k, v := range h {
+			outmd[k] = v
+		}
+	}
+	select {
+	case ss.headerc <- outmd:
+		ss.headerc = nil
+		ss.headers = nil
+		return nil
+	case <-ss.Context().Done():
+	}
+	return ss.Context().Err()
+}
+
+func (ss *chanServerStream) SetHeader(md metadata.MD) error {
+	if ss.headerc == nil {
+		return errAlreadySentHeader
+	}
+	ss.headers = append(ss.headers, md)
+	return nil
+}
+
+func (ss *chanServerStream) SetTrailer(md metadata.MD) {
+	ss.trailerc <- md
+}
+
+// chanClientStream implements grpc.ClientStream with a chanStream
+type chanClientStream struct {
+	headerc  <-chan metadata.MD
+	trailerc <-chan metadata.MD
+	*chanStream
+}
+
+func (cs *chanClientStream) Header() (metadata.MD, error) {
+	select {
+	case md := <-cs.headerc:
+		return md, nil
+	case <-cs.Context().Done():
+	}
+	return nil, cs.Context().Err()
+}
+
+func (cs *chanClientStream) Trailer() metadata.MD {
+	select {
+	case md := <-cs.trailerc:
+		return md
+	case <-cs.Context().Done():
+		return nil
+	}
+}
+
+func (cs *chanClientStream) CloseSend() error {
+	close(cs.chanStream.sendc)
+	return nil
+}
+
+// chanStream implements grpc.Stream using channels
+type chanStream struct {
+	recvc  <-chan interface{}
+	sendc  chan<- interface{}
+	ctx    context.Context
+	cancel context.CancelFunc
+}
+
+func (s *chanStream) Context() context.Context { return s.ctx }
+
+func (s *chanStream) SendMsg(m interface{}) error {
+	select {
+	case s.sendc <- m:
+		if err, ok := m.(error); ok {
+			return err
+		}
+		return nil
+	case <-s.ctx.Done():
+	}
+	return s.ctx.Err()
+}
+
+func (s *chanStream) RecvMsg(m interface{}) error {
+	v := m.(*interface{})
+	for {
+		select {
+		case msg, ok := <-s.recvc:
+			if !ok {
+				return status.Error(codes.Canceled, "the client connection is closing")
+			}
+			if err, ok := msg.(error); ok {
+				return err
+			}
+			*v = msg
+			return nil
+		case <-s.ctx.Done():
+		}
+		if len(s.recvc) == 0 {
+			// prioritize any pending recv messages over canceled context
+			break
+		}
+	}
+	return s.ctx.Err()
+}
+
+func newPipeStream(ctx context.Context, ssHandler func(chanServerStream) error) chanClientStream {
+	// ch1 is buffered so server can send error on close
+	ch1, ch2 := make(chan interface{}, 1), make(chan interface{})
+	headerc, trailerc := make(chan metadata.MD, 1), make(chan metadata.MD, 1)
+
+	cctx, ccancel := context.WithCancel(ctx)
+	cli := &chanStream{recvc: ch1, sendc: ch2, ctx: cctx, cancel: ccancel}
+	cs := chanClientStream{headerc, trailerc, cli}
+
+	sctx, scancel := context.WithCancel(ctx)
+	srv := &chanStream{recvc: ch2, sendc: ch1, ctx: sctx, cancel: scancel}
+	ss := chanServerStream{headerc, trailerc, srv, nil}
+
+	go func() {
+		if err := ssHandler(ss); err != nil {
+			select {
+			case srv.sendc <- err:
+			case <-sctx.Done():
+			case <-cctx.Done():
+			}
+		}
+		scancel()
+		ccancel()
+	}()
+	return cs
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/cluster_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/cluster_client_adapter.go
new file mode 100644
index 0000000..73a6fdf
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/cluster_client_adapter.go
@@ -0,0 +1,49 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"google.golang.org/grpc"
+)
+
+type cls2clc struct{ cls pb.ClusterServer }
+
+func ClusterServerToClusterClient(cls pb.ClusterServer) pb.ClusterClient {
+	return &cls2clc{cls}
+}
+
+func (s *cls2clc) MemberList(ctx context.Context, r *pb.MemberListRequest, opts ...grpc.CallOption) (*pb.MemberListResponse, error) {
+	return s.cls.MemberList(ctx, r)
+}
+
+func (s *cls2clc) MemberAdd(ctx context.Context, r *pb.MemberAddRequest, opts ...grpc.CallOption) (*pb.MemberAddResponse, error) {
+	return s.cls.MemberAdd(ctx, r)
+}
+
+func (s *cls2clc) MemberUpdate(ctx context.Context, r *pb.MemberUpdateRequest, opts ...grpc.CallOption) (*pb.MemberUpdateResponse, error) {
+	return s.cls.MemberUpdate(ctx, r)
+}
+
+func (s *cls2clc) MemberRemove(ctx context.Context, r *pb.MemberRemoveRequest, opts ...grpc.CallOption) (*pb.MemberRemoveResponse, error) {
+	return s.cls.MemberRemove(ctx, r)
+}
+
+func (s *cls2clc) MemberPromote(ctx context.Context, r *pb.MemberPromoteRequest, opts ...grpc.CallOption) (*pb.MemberPromoteResponse, error) {
+	return s.cls.MemberPromote(ctx, r)
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/doc.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/doc.go
new file mode 100644
index 0000000..7170be2
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/doc.go
@@ -0,0 +1,17 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package adapter provides gRPC adapters between client and server
+// gRPC interfaces without needing to go through a gRPC connection.
+package adapter
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/election_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/election_client_adapter.go
new file mode 100644
index 0000000..4722be0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/election_client_adapter.go
@@ -0,0 +1,80 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/etcdserver/api/v3election/v3electionpb"
+
+	"google.golang.org/grpc"
+)
+
+type es2ec struct{ es v3electionpb.ElectionServer }
+
+func ElectionServerToElectionClient(es v3electionpb.ElectionServer) v3electionpb.ElectionClient {
+	return &es2ec{es}
+}
+
+func (s *es2ec) Campaign(ctx context.Context, r *v3electionpb.CampaignRequest, opts ...grpc.CallOption) (*v3electionpb.CampaignResponse, error) {
+	return s.es.Campaign(ctx, r)
+}
+
+func (s *es2ec) Proclaim(ctx context.Context, r *v3electionpb.ProclaimRequest, opts ...grpc.CallOption) (*v3electionpb.ProclaimResponse, error) {
+	return s.es.Proclaim(ctx, r)
+}
+
+func (s *es2ec) Leader(ctx context.Context, r *v3electionpb.LeaderRequest, opts ...grpc.CallOption) (*v3electionpb.LeaderResponse, error) {
+	return s.es.Leader(ctx, r)
+}
+
+func (s *es2ec) Resign(ctx context.Context, r *v3electionpb.ResignRequest, opts ...grpc.CallOption) (*v3electionpb.ResignResponse, error) {
+	return s.es.Resign(ctx, r)
+}
+
+func (s *es2ec) Observe(ctx context.Context, in *v3electionpb.LeaderRequest, opts ...grpc.CallOption) (v3electionpb.Election_ObserveClient, error) {
+	cs := newPipeStream(ctx, func(ss chanServerStream) error {
+		return s.es.Observe(in, &es2ecServerStream{ss})
+	})
+	return &es2ecClientStream{cs}, nil
+}
+
+// es2ecClientStream implements Election_ObserveClient
+type es2ecClientStream struct{ chanClientStream }
+
+// es2ecServerStream implements Election_ObserveServer
+type es2ecServerStream struct{ chanServerStream }
+
+func (s *es2ecClientStream) Send(rr *v3electionpb.LeaderRequest) error {
+	return s.SendMsg(rr)
+}
+func (s *es2ecClientStream) Recv() (*v3electionpb.LeaderResponse, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*v3electionpb.LeaderResponse), nil
+}
+
+func (s *es2ecServerStream) Send(rr *v3electionpb.LeaderResponse) error {
+	return s.SendMsg(rr)
+}
+func (s *es2ecServerStream) Recv() (*v3electionpb.LeaderRequest, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*v3electionpb.LeaderRequest), nil
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/kv_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/kv_client_adapter.go
new file mode 100644
index 0000000..b1a7820
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/kv_client_adapter.go
@@ -0,0 +1,49 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	grpc "google.golang.org/grpc"
+)
+
+type kvs2kvc struct{ kvs pb.KVServer }
+
+func KvServerToKvClient(kvs pb.KVServer) pb.KVClient {
+	return &kvs2kvc{kvs}
+}
+
+func (s *kvs2kvc) Range(ctx context.Context, in *pb.RangeRequest, opts ...grpc.CallOption) (*pb.RangeResponse, error) {
+	return s.kvs.Range(ctx, in)
+}
+
+func (s *kvs2kvc) Put(ctx context.Context, in *pb.PutRequest, opts ...grpc.CallOption) (*pb.PutResponse, error) {
+	return s.kvs.Put(ctx, in)
+}
+
+func (s *kvs2kvc) DeleteRange(ctx context.Context, in *pb.DeleteRangeRequest, opts ...grpc.CallOption) (*pb.DeleteRangeResponse, error) {
+	return s.kvs.DeleteRange(ctx, in)
+}
+
+func (s *kvs2kvc) Txn(ctx context.Context, in *pb.TxnRequest, opts ...grpc.CallOption) (*pb.TxnResponse, error) {
+	return s.kvs.Txn(ctx, in)
+}
+
+func (s *kvs2kvc) Compact(ctx context.Context, in *pb.CompactionRequest, opts ...grpc.CallOption) (*pb.CompactionResponse, error) {
+	return s.kvs.Compact(ctx, in)
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lease_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lease_client_adapter.go
new file mode 100644
index 0000000..a58408f
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lease_client_adapter.go
@@ -0,0 +1,82 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"google.golang.org/grpc"
+)
+
+type ls2lc struct {
+	leaseServer pb.LeaseServer
+}
+
+func LeaseServerToLeaseClient(ls pb.LeaseServer) pb.LeaseClient {
+	return &ls2lc{ls}
+}
+
+func (c *ls2lc) LeaseGrant(ctx context.Context, in *pb.LeaseGrantRequest, opts ...grpc.CallOption) (*pb.LeaseGrantResponse, error) {
+	return c.leaseServer.LeaseGrant(ctx, in)
+}
+
+func (c *ls2lc) LeaseRevoke(ctx context.Context, in *pb.LeaseRevokeRequest, opts ...grpc.CallOption) (*pb.LeaseRevokeResponse, error) {
+	return c.leaseServer.LeaseRevoke(ctx, in)
+}
+
+func (c *ls2lc) LeaseKeepAlive(ctx context.Context, opts ...grpc.CallOption) (pb.Lease_LeaseKeepAliveClient, error) {
+	cs := newPipeStream(ctx, func(ss chanServerStream) error {
+		return c.leaseServer.LeaseKeepAlive(&ls2lcServerStream{ss})
+	})
+	return &ls2lcClientStream{cs}, nil
+}
+
+func (c *ls2lc) LeaseTimeToLive(ctx context.Context, in *pb.LeaseTimeToLiveRequest, opts ...grpc.CallOption) (*pb.LeaseTimeToLiveResponse, error) {
+	return c.leaseServer.LeaseTimeToLive(ctx, in)
+}
+
+func (c *ls2lc) LeaseLeases(ctx context.Context, in *pb.LeaseLeasesRequest, opts ...grpc.CallOption) (*pb.LeaseLeasesResponse, error) {
+	return c.leaseServer.LeaseLeases(ctx, in)
+}
+
+// ls2lcClientStream implements Lease_LeaseKeepAliveClient
+type ls2lcClientStream struct{ chanClientStream }
+
+// ls2lcServerStream implements Lease_LeaseKeepAliveServer
+type ls2lcServerStream struct{ chanServerStream }
+
+func (s *ls2lcClientStream) Send(rr *pb.LeaseKeepAliveRequest) error {
+	return s.SendMsg(rr)
+}
+func (s *ls2lcClientStream) Recv() (*pb.LeaseKeepAliveResponse, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.LeaseKeepAliveResponse), nil
+}
+
+func (s *ls2lcServerStream) Send(rr *pb.LeaseKeepAliveResponse) error {
+	return s.SendMsg(rr)
+}
+func (s *ls2lcServerStream) Recv() (*pb.LeaseKeepAliveRequest, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.LeaseKeepAliveRequest), nil
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lock_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lock_client_adapter.go
new file mode 100644
index 0000000..65b5641
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/lock_client_adapter.go
@@ -0,0 +1,37 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	"go.etcd.io/etcd/etcdserver/api/v3lock/v3lockpb"
+
+	"google.golang.org/grpc"
+)
+
+type ls2lsc struct{ ls v3lockpb.LockServer }
+
+func LockServerToLockClient(ls v3lockpb.LockServer) v3lockpb.LockClient {
+	return &ls2lsc{ls}
+}
+
+func (s *ls2lsc) Lock(ctx context.Context, r *v3lockpb.LockRequest, opts ...grpc.CallOption) (*v3lockpb.LockResponse, error) {
+	return s.ls.Lock(ctx, r)
+}
+
+func (s *ls2lsc) Unlock(ctx context.Context, r *v3lockpb.UnlockRequest, opts ...grpc.CallOption) (*v3lockpb.UnlockResponse, error) {
+	return s.ls.Unlock(ctx, r)
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/maintenance_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/maintenance_client_adapter.go
new file mode 100644
index 0000000..4a8781b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/maintenance_client_adapter.go
@@ -0,0 +1,88 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+
+	"google.golang.org/grpc"
+)
+
+type mts2mtc struct{ mts pb.MaintenanceServer }
+
+func MaintenanceServerToMaintenanceClient(mts pb.MaintenanceServer) pb.MaintenanceClient {
+	return &mts2mtc{mts}
+}
+
+func (s *mts2mtc) Alarm(ctx context.Context, r *pb.AlarmRequest, opts ...grpc.CallOption) (*pb.AlarmResponse, error) {
+	return s.mts.Alarm(ctx, r)
+}
+
+func (s *mts2mtc) Status(ctx context.Context, r *pb.StatusRequest, opts ...grpc.CallOption) (*pb.StatusResponse, error) {
+	return s.mts.Status(ctx, r)
+}
+
+func (s *mts2mtc) Defragment(ctx context.Context, dr *pb.DefragmentRequest, opts ...grpc.CallOption) (*pb.DefragmentResponse, error) {
+	return s.mts.Defragment(ctx, dr)
+}
+
+func (s *mts2mtc) Hash(ctx context.Context, r *pb.HashRequest, opts ...grpc.CallOption) (*pb.HashResponse, error) {
+	return s.mts.Hash(ctx, r)
+}
+
+func (s *mts2mtc) HashKV(ctx context.Context, r *pb.HashKVRequest, opts ...grpc.CallOption) (*pb.HashKVResponse, error) {
+	return s.mts.HashKV(ctx, r)
+}
+
+func (s *mts2mtc) MoveLeader(ctx context.Context, r *pb.MoveLeaderRequest, opts ...grpc.CallOption) (*pb.MoveLeaderResponse, error) {
+	return s.mts.MoveLeader(ctx, r)
+}
+
+func (s *mts2mtc) Snapshot(ctx context.Context, in *pb.SnapshotRequest, opts ...grpc.CallOption) (pb.Maintenance_SnapshotClient, error) {
+	cs := newPipeStream(ctx, func(ss chanServerStream) error {
+		return s.mts.Snapshot(in, &ss2scServerStream{ss})
+	})
+	return &ss2scClientStream{cs}, nil
+}
+
+// ss2scClientStream implements Maintenance_SnapshotClient
+type ss2scClientStream struct{ chanClientStream }
+
+// ss2scServerStream implements Maintenance_SnapshotServer
+type ss2scServerStream struct{ chanServerStream }
+
+func (s *ss2scClientStream) Send(rr *pb.SnapshotRequest) error {
+	return s.SendMsg(rr)
+}
+func (s *ss2scClientStream) Recv() (*pb.SnapshotResponse, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.SnapshotResponse), nil
+}
+
+func (s *ss2scServerStream) Send(rr *pb.SnapshotResponse) error {
+	return s.SendMsg(rr)
+}
+func (s *ss2scServerStream) Recv() (*pb.SnapshotRequest, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.SnapshotRequest), nil
+}
diff --git a/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/watch_client_adapter.go b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/watch_client_adapter.go
new file mode 100644
index 0000000..2f629cc
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/proxy/grpcproxy/adapter/watch_client_adapter.go
@@ -0,0 +1,66 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adapter
+
+import (
+	"context"
+	"errors"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"google.golang.org/grpc"
+)
+
+var errAlreadySentHeader = errors.New("adapter: already sent header")
+
+type ws2wc struct{ wserv pb.WatchServer }
+
+func WatchServerToWatchClient(wserv pb.WatchServer) pb.WatchClient {
+	return &ws2wc{wserv}
+}
+
+func (s *ws2wc) Watch(ctx context.Context, opts ...grpc.CallOption) (pb.Watch_WatchClient, error) {
+	cs := newPipeStream(ctx, func(ss chanServerStream) error {
+		return s.wserv.Watch(&ws2wcServerStream{ss})
+	})
+	return &ws2wcClientStream{cs}, nil
+}
+
+// ws2wcClientStream implements Watch_WatchClient
+type ws2wcClientStream struct{ chanClientStream }
+
+// ws2wcServerStream implements Watch_WatchServer
+type ws2wcServerStream struct{ chanServerStream }
+
+func (s *ws2wcClientStream) Send(wr *pb.WatchRequest) error {
+	return s.SendMsg(wr)
+}
+func (s *ws2wcClientStream) Recv() (*pb.WatchResponse, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.WatchResponse), nil
+}
+
+func (s *ws2wcServerStream) Send(wr *pb.WatchResponse) error {
+	return s.SendMsg(wr)
+}
+func (s *ws2wcServerStream) Recv() (*pb.WatchRequest, error) {
+	var v interface{}
+	if err := s.RecvMsg(&v); err != nil {
+		return nil, err
+	}
+	return v.(*pb.WatchRequest), nil
+}
diff --git a/vendor/go.etcd.io/etcd/version/version.go b/vendor/go.etcd.io/etcd/version/version.go
new file mode 100644
index 0000000..622e751
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/version/version.go
@@ -0,0 +1,56 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package version implements etcd version parsing and contains latest version
+// information.
+package version
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/coreos/go-semver/semver"
+)
+
+var (
+	// MinClusterVersion is the min cluster version this etcd binary is compatible with.
+	MinClusterVersion = "3.0.0"
+	Version           = "3.5.0-pre"
+	APIVersion        = "unknown"
+
+	// Git SHA Value will be set during build
+	GitSHA = "Not provided (use ./build instead of go build)"
+)
+
+func init() {
+	ver, err := semver.NewVersion(Version)
+	if err == nil {
+		APIVersion = fmt.Sprintf("%d.%d", ver.Major, ver.Minor)
+	}
+}
+
+type Versions struct {
+	Server  string `json:"etcdserver"`
+	Cluster string `json:"etcdcluster"`
+	// TODO: raft state machine version
+}
+
+// Cluster only keeps the major.minor.
+func Cluster(v string) string {
+	vs := strings.Split(v, ".")
+	if len(vs) <= 2 {
+		return v
+	}
+	return fmt.Sprintf("%s.%s", vs[0], vs[1])
+}
diff --git a/vendor/go.etcd.io/etcd/wal/decoder.go b/vendor/go.etcd.io/etcd/wal/decoder.go
new file mode 100644
index 0000000..f2f01fd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/decoder.go
@@ -0,0 +1,188 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"bufio"
+	"encoding/binary"
+	"hash"
+	"io"
+	"sync"
+
+	"go.etcd.io/etcd/pkg/crc"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/wal/walpb"
+)
+
+const minSectorSize = 512
+
+// frameSizeBytes is frame size in bytes, including record size and padding size.
+const frameSizeBytes = 8
+
+type decoder struct {
+	mu  sync.Mutex
+	brs []*bufio.Reader
+
+	// lastValidOff file offset following the last valid decoded record
+	lastValidOff int64
+	crc          hash.Hash32
+}
+
+func newDecoder(r ...io.Reader) *decoder {
+	readers := make([]*bufio.Reader, len(r))
+	for i := range r {
+		readers[i] = bufio.NewReader(r[i])
+	}
+	return &decoder{
+		brs: readers,
+		crc: crc.New(0, crcTable),
+	}
+}
+
+func (d *decoder) decode(rec *walpb.Record) error {
+	rec.Reset()
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	return d.decodeRecord(rec)
+}
+
+func (d *decoder) decodeRecord(rec *walpb.Record) error {
+	if len(d.brs) == 0 {
+		return io.EOF
+	}
+
+	l, err := readInt64(d.brs[0])
+	if err == io.EOF || (err == nil && l == 0) {
+		// hit end of file or preallocated space
+		d.brs = d.brs[1:]
+		if len(d.brs) == 0 {
+			return io.EOF
+		}
+		d.lastValidOff = 0
+		return d.decodeRecord(rec)
+	}
+	if err != nil {
+		return err
+	}
+
+	recBytes, padBytes := decodeFrameSize(l)
+
+	data := make([]byte, recBytes+padBytes)
+	if _, err = io.ReadFull(d.brs[0], data); err != nil {
+		// ReadFull returns io.EOF only if no bytes were read
+		// the decoder should treat this as an ErrUnexpectedEOF instead.
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return err
+	}
+	if err := rec.Unmarshal(data[:recBytes]); err != nil {
+		if d.isTornEntry(data) {
+			return io.ErrUnexpectedEOF
+		}
+		return err
+	}
+
+	// skip crc checking if the record type is crcType
+	if rec.Type != crcType {
+		d.crc.Write(rec.Data)
+		if err := rec.Validate(d.crc.Sum32()); err != nil {
+			if d.isTornEntry(data) {
+				return io.ErrUnexpectedEOF
+			}
+			return err
+		}
+	}
+	// record decoded as valid; point last valid offset to end of record
+	d.lastValidOff += frameSizeBytes + recBytes + padBytes
+	return nil
+}
+
+func decodeFrameSize(lenField int64) (recBytes int64, padBytes int64) {
+	// the record size is stored in the lower 56 bits of the 64-bit length
+	recBytes = int64(uint64(lenField) & ^(uint64(0xff) << 56))
+	// non-zero padding is indicated by set MSb / a negative length
+	if lenField < 0 {
+		// padding is stored in lower 3 bits of length MSB
+		padBytes = int64((uint64(lenField) >> 56) & 0x7)
+	}
+	return recBytes, padBytes
+}
+
+// isTornEntry determines whether the last entry of the WAL was partially written
+// and corrupted because of a torn write.
+func (d *decoder) isTornEntry(data []byte) bool {
+	if len(d.brs) != 1 {
+		return false
+	}
+
+	fileOff := d.lastValidOff + frameSizeBytes
+	curOff := 0
+	chunks := [][]byte{}
+	// split data on sector boundaries
+	for curOff < len(data) {
+		chunkLen := int(minSectorSize - (fileOff % minSectorSize))
+		if chunkLen > len(data)-curOff {
+			chunkLen = len(data) - curOff
+		}
+		chunks = append(chunks, data[curOff:curOff+chunkLen])
+		fileOff += int64(chunkLen)
+		curOff += chunkLen
+	}
+
+	// if any data for a sector chunk is all 0, it's a torn write
+	for _, sect := range chunks {
+		isZero := true
+		for _, v := range sect {
+			if v != 0 {
+				isZero = false
+				break
+			}
+		}
+		if isZero {
+			return true
+		}
+	}
+	return false
+}
+
+func (d *decoder) updateCRC(prevCrc uint32) {
+	d.crc = crc.New(prevCrc, crcTable)
+}
+
+func (d *decoder) lastCRC() uint32 {
+	return d.crc.Sum32()
+}
+
+func (d *decoder) lastOffset() int64 { return d.lastValidOff }
+
+func mustUnmarshalEntry(d []byte) raftpb.Entry {
+	var e raftpb.Entry
+	pbutil.MustUnmarshal(&e, d)
+	return e
+}
+
+func mustUnmarshalState(d []byte) raftpb.HardState {
+	var s raftpb.HardState
+	pbutil.MustUnmarshal(&s, d)
+	return s
+}
+
+func readInt64(r io.Reader) (int64, error) {
+	var n int64
+	err := binary.Read(r, binary.LittleEndian, &n)
+	return n, err
+}
diff --git a/vendor/go.etcd.io/etcd/wal/doc.go b/vendor/go.etcd.io/etcd/wal/doc.go
new file mode 100644
index 0000000..7ea348e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/doc.go
@@ -0,0 +1,75 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package wal provides an implementation of a write ahead log that is used by
+etcd.
+
+A WAL is created at a particular directory and is made up of a number of
+segmented WAL files. Inside of each file the raft state and entries are appended
+to it with the Save method:
+
+	metadata := []byte{}
+	w, err := wal.Create(zap.NewExample(), "/var/lib/etcd", metadata)
+	...
+	err := w.Save(s, ents)
+
+After saving a raft snapshot to disk, SaveSnapshot method should be called to
+record it. So WAL can match with the saved snapshot when restarting.
+
+	err := w.SaveSnapshot(walpb.Snapshot{Index: 10, Term: 2})
+
+When a user has finished using a WAL it must be closed:
+
+	w.Close()
+
+Each WAL file is a stream of WAL records. A WAL record is a length field and a wal record
+protobuf. The record protobuf contains a CRC, a type, and a data payload. The length field is a
+64-bit packed structure holding the length of the remaining logical record data in its lower
+56 bits and its physical padding in the first three bits of the most significant byte. Each
+record is 8-byte aligned so that the length field is never torn. The CRC contains the CRC32
+value of all record protobufs preceding the current record.
+
+WAL files are placed inside of the directory in the following format:
+$seq-$index.wal
+
+The first WAL file to be created will be 0000000000000000-0000000000000000.wal
+indicating an initial sequence of 0 and an initial raft index of 0. The first
+entry written to WAL MUST have raft index 0.
+
+WAL will cut its current tail wal file if its size exceeds 64MB. This will increment an internal
+sequence number and cause a new file to be created. If the last raft index saved
+was 0x20 and this is the first time cut has been called on this WAL then the sequence will
+increment from 0x0 to 0x1. The new file will be: 0000000000000001-0000000000000021.wal.
+If a second cut issues 0x10 entries with incremental index later then the file will be called:
+0000000000000002-0000000000000031.wal.
+
+At a later time a WAL can be opened at a particular snapshot. If there is no
+snapshot, an empty snapshot should be passed in.
+
+	w, err := wal.Open("/var/lib/etcd", walpb.Snapshot{Index: 10, Term: 2})
+	...
+
+The snapshot must have been written to the WAL.
+
+Additional items cannot be Saved to this WAL until all of the items from the given
+snapshot to the end of the WAL are read first:
+
+	metadata, state, ents, err := w.ReadAll()
+
+This will give you the metadata, the last raft.State and the slice of
+raft.Entry items in the log.
+
+*/
+package wal
diff --git a/vendor/go.etcd.io/etcd/wal/encoder.go b/vendor/go.etcd.io/etcd/wal/encoder.go
new file mode 100644
index 0000000..d3877ed
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/encoder.go
@@ -0,0 +1,120 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"encoding/binary"
+	"hash"
+	"io"
+	"os"
+	"sync"
+
+	"go.etcd.io/etcd/pkg/crc"
+	"go.etcd.io/etcd/pkg/ioutil"
+	"go.etcd.io/etcd/wal/walpb"
+)
+
+// walPageBytes is the alignment for flushing records to the backing Writer.
+// It should be a multiple of the minimum sector size so that WAL can safely
+// distinguish between torn writes and ordinary data corruption.
+const walPageBytes = 8 * minSectorSize
+
+type encoder struct {
+	mu sync.Mutex
+	bw *ioutil.PageWriter
+
+	crc       hash.Hash32
+	buf       []byte
+	uint64buf []byte
+}
+
+func newEncoder(w io.Writer, prevCrc uint32, pageOffset int) *encoder {
+	return &encoder{
+		bw:  ioutil.NewPageWriter(w, walPageBytes, pageOffset),
+		crc: crc.New(prevCrc, crcTable),
+		// 1MB buffer
+		buf:       make([]byte, 1024*1024),
+		uint64buf: make([]byte, 8),
+	}
+}
+
+// newFileEncoder creates a new encoder with current file offset for the page writer.
+func newFileEncoder(f *os.File, prevCrc uint32) (*encoder, error) {
+	offset, err := f.Seek(0, io.SeekCurrent)
+	if err != nil {
+		return nil, err
+	}
+	return newEncoder(f, prevCrc, int(offset)), nil
+}
+
+func (e *encoder) encode(rec *walpb.Record) error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	e.crc.Write(rec.Data)
+	rec.Crc = e.crc.Sum32()
+	var (
+		data []byte
+		err  error
+		n    int
+	)
+
+	if rec.Size() > len(e.buf) {
+		data, err = rec.Marshal()
+		if err != nil {
+			return err
+		}
+	} else {
+		n, err = rec.MarshalTo(e.buf)
+		if err != nil {
+			return err
+		}
+		data = e.buf[:n]
+	}
+
+	lenField, padBytes := encodeFrameSize(len(data))
+	if err = writeUint64(e.bw, lenField, e.uint64buf); err != nil {
+		return err
+	}
+
+	if padBytes != 0 {
+		data = append(data, make([]byte, padBytes)...)
+	}
+	_, err = e.bw.Write(data)
+	return err
+}
+
+func encodeFrameSize(dataBytes int) (lenField uint64, padBytes int) {
+	lenField = uint64(dataBytes)
+	// force 8 byte alignment so length never gets a torn write
+	padBytes = (8 - (dataBytes % 8)) % 8
+	if padBytes != 0 {
+		lenField |= uint64(0x80|padBytes) << 56
+	}
+	return lenField, padBytes
+}
+
+func (e *encoder) flush() error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.bw.Flush()
+}
+
+func writeUint64(w io.Writer, n uint64, buf []byte) error {
+	// http://golang.org/src/encoding/binary/binary.go
+	binary.LittleEndian.PutUint64(buf, n)
+	_, err := w.Write(buf)
+	return err
+}
diff --git a/vendor/go.etcd.io/etcd/wal/file_pipeline.go b/vendor/go.etcd.io/etcd/wal/file_pipeline.go
new file mode 100644
index 0000000..e1e1c55
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/file_pipeline.go
@@ -0,0 +1,106 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+
+	"go.uber.org/zap"
+)
+
+// filePipeline pipelines allocating disk space
+type filePipeline struct {
+	lg *zap.Logger
+
+	// dir to put files
+	dir string
+	// size of files to make, in bytes
+	size int64
+	// count number of files generated
+	count int
+
+	filec chan *fileutil.LockedFile
+	errc  chan error
+	donec chan struct{}
+}
+
+func newFilePipeline(lg *zap.Logger, dir string, fileSize int64) *filePipeline {
+	fp := &filePipeline{
+		lg:    lg,
+		dir:   dir,
+		size:  fileSize,
+		filec: make(chan *fileutil.LockedFile),
+		errc:  make(chan error, 1),
+		donec: make(chan struct{}),
+	}
+	go fp.run()
+	return fp
+}
+
+// Open returns a fresh file for writing. Rename the file before calling
+// Open again or there will be file collisions.
+func (fp *filePipeline) Open() (f *fileutil.LockedFile, err error) {
+	select {
+	case f = <-fp.filec:
+	case err = <-fp.errc:
+	}
+	return f, err
+}
+
+func (fp *filePipeline) Close() error {
+	close(fp.donec)
+	return <-fp.errc
+}
+
+func (fp *filePipeline) alloc() (f *fileutil.LockedFile, err error) {
+	// count % 2 so this file isn't the same as the one last published
+	fpath := filepath.Join(fp.dir, fmt.Sprintf("%d.tmp", fp.count%2))
+	if f, err = fileutil.LockFile(fpath, os.O_CREATE|os.O_WRONLY, fileutil.PrivateFileMode); err != nil {
+		return nil, err
+	}
+	if err = fileutil.Preallocate(f.File, fp.size, true); err != nil {
+		if fp.lg != nil {
+			fp.lg.Warn("failed to preallocate space when creating a new WAL", zap.Int64("size", fp.size), zap.Error(err))
+		} else {
+			plog.Errorf("failed to allocate space when creating new wal file (%v)", err)
+		}
+		f.Close()
+		return nil, err
+	}
+	fp.count++
+	return f, nil
+}
+
+func (fp *filePipeline) run() {
+	defer close(fp.errc)
+	for {
+		f, err := fp.alloc()
+		if err != nil {
+			fp.errc <- err
+			return
+		}
+		select {
+		case fp.filec <- f:
+		case <-fp.donec:
+			os.Remove(f.Name())
+			f.Close()
+			return
+		}
+	}
+}
diff --git a/vendor/go.etcd.io/etcd/wal/metrics.go b/vendor/go.etcd.io/etcd/wal/metrics.go
new file mode 100644
index 0000000..22cb800
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/metrics.go
@@ -0,0 +1,34 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import "github.com/prometheus/client_golang/prometheus"
+
+var (
+	walFsyncSec = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Namespace: "etcd",
+		Subsystem: "disk",
+		Name:      "wal_fsync_duration_seconds",
+		Help:      "The latency distributions of fsync called by WAL.",
+
+		// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
+		// highest bucket start of 0.001 sec * 2^13 == 8.192 sec
+		Buckets: prometheus.ExponentialBuckets(0.001, 2, 14),
+	})
+)
+
+func init() {
+	prometheus.MustRegister(walFsyncSec)
+}
diff --git a/vendor/go.etcd.io/etcd/wal/repair.go b/vendor/go.etcd.io/etcd/wal/repair.go
new file mode 100644
index 0000000..15afed0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/repair.go
@@ -0,0 +1,141 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+	"go.etcd.io/etcd/wal/walpb"
+
+	"go.uber.org/zap"
+)
+
+// Repair tries to repair ErrUnexpectedEOF in the
+// last wal file by truncating.
+func Repair(lg *zap.Logger, dirpath string) bool {
+	f, err := openLast(lg, dirpath)
+	if err != nil {
+		return false
+	}
+	defer f.Close()
+
+	if lg != nil {
+		lg.Info("repairing", zap.String("path", f.Name()))
+	} else {
+		plog.Noticef("repairing %v", f.Name())
+	}
+
+	rec := &walpb.Record{}
+	decoder := newDecoder(f)
+	for {
+		lastOffset := decoder.lastOffset()
+		err := decoder.decode(rec)
+		switch err {
+		case nil:
+			// update crc of the decoder when necessary
+			switch rec.Type {
+			case crcType:
+				crc := decoder.crc.Sum32()
+				// current crc of decoder must match the crc of the record.
+				// do no need to match 0 crc, since the decoder is a new one at this case.
+				if crc != 0 && rec.Validate(crc) != nil {
+					return false
+				}
+				decoder.updateCRC(rec.Crc)
+			}
+			continue
+
+		case io.EOF:
+			if lg != nil {
+				lg.Info("repaired", zap.String("path", f.Name()), zap.Error(io.EOF))
+			}
+			return true
+
+		case io.ErrUnexpectedEOF:
+			bf, bferr := os.Create(f.Name() + ".broken")
+			if bferr != nil {
+				if lg != nil {
+					lg.Warn("failed to create backup file", zap.String("path", f.Name()+".broken"), zap.Error(bferr))
+				} else {
+					plog.Errorf("could not repair %v, failed to create backup file", f.Name())
+				}
+				return false
+			}
+			defer bf.Close()
+
+			if _, err = f.Seek(0, io.SeekStart); err != nil {
+				if lg != nil {
+					lg.Warn("failed to read file", zap.String("path", f.Name()), zap.Error(err))
+				} else {
+					plog.Errorf("could not repair %v, failed to read file", f.Name())
+				}
+				return false
+			}
+
+			if _, err = io.Copy(bf, f); err != nil {
+				if lg != nil {
+					lg.Warn("failed to copy", zap.String("from", f.Name()+".broken"), zap.String("to", f.Name()), zap.Error(err))
+				} else {
+					plog.Errorf("could not repair %v, failed to copy file", f.Name())
+				}
+				return false
+			}
+
+			if err = f.Truncate(lastOffset); err != nil {
+				if lg != nil {
+					lg.Warn("failed to truncate", zap.String("path", f.Name()), zap.Error(err))
+				} else {
+					plog.Errorf("could not repair %v, failed to truncate file", f.Name())
+				}
+				return false
+			}
+
+			if err = fileutil.Fsync(f.File); err != nil {
+				if lg != nil {
+					lg.Warn("failed to fsync", zap.String("path", f.Name()), zap.Error(err))
+				} else {
+					plog.Errorf("could not repair %v, failed to sync file", f.Name())
+				}
+				return false
+			}
+
+			if lg != nil {
+				lg.Info("repaired", zap.String("path", f.Name()), zap.Error(io.ErrUnexpectedEOF))
+			}
+			return true
+
+		default:
+			if lg != nil {
+				lg.Warn("failed to repair", zap.String("path", f.Name()), zap.Error(err))
+			} else {
+				plog.Errorf("could not repair error (%v)", err)
+			}
+			return false
+		}
+	}
+}
+
+// openLast opens the last wal file for read and write.
+func openLast(lg *zap.Logger, dirpath string) (*fileutil.LockedFile, error) {
+	names, err := readWALNames(lg, dirpath)
+	if err != nil {
+		return nil, err
+	}
+	last := filepath.Join(dirpath, names[len(names)-1])
+	return fileutil.LockFile(last, os.O_RDWR, fileutil.PrivateFileMode)
+}
diff --git a/vendor/go.etcd.io/etcd/wal/util.go b/vendor/go.etcd.io/etcd/wal/util.go
new file mode 100644
index 0000000..a3f314b
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/util.go
@@ -0,0 +1,124 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+
+	"go.uber.org/zap"
+)
+
+var errBadWALName = errors.New("bad wal name")
+
+// Exist returns true if there are any files in a given directory.
+func Exist(dir string) bool {
+	names, err := fileutil.ReadDir(dir, fileutil.WithExt(".wal"))
+	if err != nil {
+		return false
+	}
+	return len(names) != 0
+}
+
+// searchIndex returns the last array index of names whose raft index section is
+// equal to or smaller than the given index.
+// The given names MUST be sorted.
+func searchIndex(lg *zap.Logger, names []string, index uint64) (int, bool) {
+	for i := len(names) - 1; i >= 0; i-- {
+		name := names[i]
+		_, curIndex, err := parseWALName(name)
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to parse WAL file name", zap.String("path", name), zap.Error(err))
+			} else {
+				plog.Panicf("parse correct name should never fail: %v", err)
+			}
+		}
+		if index >= curIndex {
+			return i, true
+		}
+	}
+	return -1, false
+}
+
+// names should have been sorted based on sequence number.
+// isValidSeq checks whether seq increases continuously.
+func isValidSeq(lg *zap.Logger, names []string) bool {
+	var lastSeq uint64
+	for _, name := range names {
+		curSeq, _, err := parseWALName(name)
+		if err != nil {
+			if lg != nil {
+				lg.Panic("failed to parse WAL file name", zap.String("path", name), zap.Error(err))
+			} else {
+				plog.Panicf("parse correct name should never fail: %v", err)
+			}
+		}
+		if lastSeq != 0 && lastSeq != curSeq-1 {
+			return false
+		}
+		lastSeq = curSeq
+	}
+	return true
+}
+
+func readWALNames(lg *zap.Logger, dirpath string) ([]string, error) {
+	names, err := fileutil.ReadDir(dirpath)
+	if err != nil {
+		return nil, err
+	}
+	wnames := checkWalNames(lg, names)
+	if len(wnames) == 0 {
+		return nil, ErrFileNotFound
+	}
+	return wnames, nil
+}
+
+func checkWalNames(lg *zap.Logger, names []string) []string {
+	wnames := make([]string, 0)
+	for _, name := range names {
+		if _, _, err := parseWALName(name); err != nil {
+			// don't complain about left over tmp files
+			if !strings.HasSuffix(name, ".tmp") {
+				if lg != nil {
+					lg.Warn(
+						"ignored file in WAL directory",
+						zap.String("path", name),
+					)
+				} else {
+					plog.Warningf("ignored file %v in wal", name)
+				}
+			}
+			continue
+		}
+		wnames = append(wnames, name)
+	}
+	return wnames
+}
+
+func parseWALName(str string) (seq, index uint64, err error) {
+	if !strings.HasSuffix(str, ".wal") {
+		return 0, 0, errBadWALName
+	}
+	_, err = fmt.Sscanf(str, "%016x-%016x.wal", &seq, &index)
+	return seq, index, err
+}
+
+func walName(seq, index uint64) string {
+	return fmt.Sprintf("%016x-%016x.wal", seq, index)
+}
diff --git a/vendor/go.etcd.io/etcd/wal/wal.go b/vendor/go.etcd.io/etcd/wal/wal.go
new file mode 100644
index 0000000..e177c8e
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/wal.go
@@ -0,0 +1,912 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wal
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"hash/crc32"
+	"io"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+
+	"go.etcd.io/etcd/pkg/fileutil"
+	"go.etcd.io/etcd/pkg/pbutil"
+	"go.etcd.io/etcd/raft"
+	"go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/wal/walpb"
+
+	"github.com/coreos/pkg/capnslog"
+	"go.uber.org/zap"
+)
+
+const (
+	metadataType int64 = iota + 1
+	entryType
+	stateType
+	crcType
+	snapshotType
+
+	// warnSyncDuration is the amount of time allotted to an fsync before
+	// logging a warning
+	warnSyncDuration = time.Second
+)
+
+var (
+	// SegmentSizeBytes is the preallocated size of each wal segment file.
+	// The actual size might be larger than this. In general, the default
+	// value should be used, but this is defined as an exported variable
+	// so that tests can set a different segment size.
+	SegmentSizeBytes int64 = 64 * 1000 * 1000 // 64MB
+
+	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "wal")
+
+	ErrMetadataConflict = errors.New("wal: conflicting metadata found")
+	ErrFileNotFound     = errors.New("wal: file not found")
+	ErrCRCMismatch      = errors.New("wal: crc mismatch")
+	ErrSnapshotMismatch = errors.New("wal: snapshot mismatch")
+	ErrSnapshotNotFound = errors.New("wal: snapshot not found")
+	crcTable            = crc32.MakeTable(crc32.Castagnoli)
+)
+
+// WAL is a logical representation of the stable storage.
+// WAL is either in read mode or append mode but not both.
+// A newly created WAL is in append mode, and ready for appending records.
+// A just opened WAL is in read mode, and ready for reading records.
+// The WAL will be ready for appending after reading out all the previous records.
+type WAL struct {
+	lg *zap.Logger
+
+	dir string // the living directory of the underlay files
+
+	// dirFile is a fd for the wal directory for syncing on Rename
+	dirFile *os.File
+
+	metadata []byte           // metadata recorded at the head of each WAL
+	state    raftpb.HardState // hardstate recorded at the head of WAL
+
+	start     walpb.Snapshot // snapshot to start reading
+	decoder   *decoder       // decoder to decode records
+	readClose func() error   // closer for decode reader
+
+	mu      sync.Mutex
+	enti    uint64   // index of the last entry saved to the wal
+	encoder *encoder // encoder to encode records
+
+	locks []*fileutil.LockedFile // the locked files the WAL holds (the name is increasing)
+	fp    *filePipeline
+}
+
+// Create creates a WAL ready for appending records. The given metadata is
+// recorded at the head of each WAL file, and can be retrieved with ReadAll.
+func Create(lg *zap.Logger, dirpath string, metadata []byte) (*WAL, error) {
+	if Exist(dirpath) {
+		return nil, os.ErrExist
+	}
+
+	// keep temporary wal directory so WAL initialization appears atomic
+	tmpdirpath := filepath.Clean(dirpath) + ".tmp"
+	if fileutil.Exist(tmpdirpath) {
+		if err := os.RemoveAll(tmpdirpath); err != nil {
+			return nil, err
+		}
+	}
+	if err := fileutil.CreateDirAll(tmpdirpath); err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to create a temporary WAL directory",
+				zap.String("tmp-dir-path", tmpdirpath),
+				zap.String("dir-path", dirpath),
+				zap.Error(err),
+			)
+		}
+		return nil, err
+	}
+
+	p := filepath.Join(tmpdirpath, walName(0, 0))
+	f, err := fileutil.LockFile(p, os.O_WRONLY|os.O_CREATE, fileutil.PrivateFileMode)
+	if err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to flock an initial WAL file",
+				zap.String("path", p),
+				zap.Error(err),
+			)
+		}
+		return nil, err
+	}
+	if _, err = f.Seek(0, io.SeekEnd); err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to seek an initial WAL file",
+				zap.String("path", p),
+				zap.Error(err),
+			)
+		}
+		return nil, err
+	}
+	if err = fileutil.Preallocate(f.File, SegmentSizeBytes, true); err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to preallocate an initial WAL file",
+				zap.String("path", p),
+				zap.Int64("segment-bytes", SegmentSizeBytes),
+				zap.Error(err),
+			)
+		}
+		return nil, err
+	}
+
+	w := &WAL{
+		lg:       lg,
+		dir:      dirpath,
+		metadata: metadata,
+	}
+	w.encoder, err = newFileEncoder(f.File, 0)
+	if err != nil {
+		return nil, err
+	}
+	w.locks = append(w.locks, f)
+	if err = w.saveCrc(0); err != nil {
+		return nil, err
+	}
+	if err = w.encoder.encode(&walpb.Record{Type: metadataType, Data: metadata}); err != nil {
+		return nil, err
+	}
+	if err = w.SaveSnapshot(walpb.Snapshot{}); err != nil {
+		return nil, err
+	}
+
+	if w, err = w.renameWAL(tmpdirpath); err != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to rename the temporary WAL directory",
+				zap.String("tmp-dir-path", tmpdirpath),
+				zap.String("dir-path", w.dir),
+				zap.Error(err),
+			)
+		}
+		return nil, err
+	}
+
+	var perr error
+	defer func() {
+		if perr != nil {
+			w.cleanupWAL(lg)
+		}
+	}()
+
+	// directory was renamed; sync parent dir to persist rename
+	pdir, perr := fileutil.OpenDir(filepath.Dir(w.dir))
+	if perr != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to open the parent data directory",
+				zap.String("parent-dir-path", filepath.Dir(w.dir)),
+				zap.String("dir-path", w.dir),
+				zap.Error(perr),
+			)
+		}
+		return nil, perr
+	}
+	if perr = fileutil.Fsync(pdir); perr != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to fsync the parent data directory file",
+				zap.String("parent-dir-path", filepath.Dir(w.dir)),
+				zap.String("dir-path", w.dir),
+				zap.Error(perr),
+			)
+		}
+		return nil, perr
+	}
+	if perr = pdir.Close(); perr != nil {
+		if lg != nil {
+			lg.Warn(
+				"failed to close the parent data directory file",
+				zap.String("parent-dir-path", filepath.Dir(w.dir)),
+				zap.String("dir-path", w.dir),
+				zap.Error(perr),
+			)
+		}
+		return nil, perr
+	}
+
+	return w, nil
+}
+
+func (w *WAL) cleanupWAL(lg *zap.Logger) {
+	var err error
+	if err = w.Close(); err != nil {
+		if lg != nil {
+			lg.Panic("failed to close WAL during cleanup", zap.Error(err))
+		} else {
+			plog.Panicf("failed to close WAL during cleanup: %v", err)
+		}
+	}
+	brokenDirName := fmt.Sprintf("%s.broken.%v", w.dir, time.Now().Format("20060102.150405.999999"))
+	if err = os.Rename(w.dir, brokenDirName); err != nil {
+		if lg != nil {
+			lg.Panic(
+				"failed to rename WAL during cleanup",
+				zap.Error(err),
+				zap.String("source-path", w.dir),
+				zap.String("rename-path", brokenDirName),
+			)
+		} else {
+			plog.Panicf("failed to rename WAL during cleanup: %v", err)
+		}
+	}
+}
+
+func (w *WAL) renameWAL(tmpdirpath string) (*WAL, error) {
+	if err := os.RemoveAll(w.dir); err != nil {
+		return nil, err
+	}
+	// On non-Windows platforms, hold the lock while renaming. Releasing
+	// the lock and trying to reacquire it quickly can be flaky because
+	// it's possible the process will fork to spawn a process while this is
+	// happening. The fds are set up as close-on-exec by the Go runtime,
+	// but there is a window between the fork and the exec where another
+	// process holds the lock.
+	if err := os.Rename(tmpdirpath, w.dir); err != nil {
+		if _, ok := err.(*os.LinkError); ok {
+			return w.renameWALUnlock(tmpdirpath)
+		}
+		return nil, err
+	}
+	w.fp = newFilePipeline(w.lg, w.dir, SegmentSizeBytes)
+	df, err := fileutil.OpenDir(w.dir)
+	w.dirFile = df
+	return w, err
+}
+
+func (w *WAL) renameWALUnlock(tmpdirpath string) (*WAL, error) {
+	// rename of directory with locked files doesn't work on windows/cifs;
+	// close the WAL to release the locks so the directory can be renamed.
+	if w.lg != nil {
+		w.lg.Info(
+			"closing WAL to release flock and retry directory renaming",
+			zap.String("from", tmpdirpath),
+			zap.String("to", w.dir),
+		)
+	} else {
+		plog.Infof("releasing file lock to rename %q to %q", tmpdirpath, w.dir)
+	}
+	w.Close()
+
+	if err := os.Rename(tmpdirpath, w.dir); err != nil {
+		return nil, err
+	}
+
+	// reopen and relock
+	newWAL, oerr := Open(w.lg, w.dir, walpb.Snapshot{})
+	if oerr != nil {
+		return nil, oerr
+	}
+	if _, _, _, err := newWAL.ReadAll(); err != nil {
+		newWAL.Close()
+		return nil, err
+	}
+	return newWAL, nil
+}
+
+// Open opens the WAL at the given snap.
+// The snap SHOULD have been previously saved to the WAL, or the following
+// ReadAll will fail.
+// The returned WAL is ready to read and the first record will be the one after
+// the given snap. The WAL cannot be appended to before reading out all of its
+// previous records.
+func Open(lg *zap.Logger, dirpath string, snap walpb.Snapshot) (*WAL, error) {
+	w, err := openAtIndex(lg, dirpath, snap, true)
+	if err != nil {
+		return nil, err
+	}
+	if w.dirFile, err = fileutil.OpenDir(w.dir); err != nil {
+		return nil, err
+	}
+	return w, nil
+}
+
+// OpenForRead only opens the wal files for read.
+// Write on a read only wal panics.
+func OpenForRead(lg *zap.Logger, dirpath string, snap walpb.Snapshot) (*WAL, error) {
+	return openAtIndex(lg, dirpath, snap, false)
+}
+
+func openAtIndex(lg *zap.Logger, dirpath string, snap walpb.Snapshot, write bool) (*WAL, error) {
+	names, nameIndex, err := selectWALFiles(lg, dirpath, snap)
+	if err != nil {
+		return nil, err
+	}
+
+	rs, ls, closer, err := openWALFiles(lg, dirpath, names, nameIndex, write)
+	if err != nil {
+		return nil, err
+	}
+
+	// create a WAL ready for reading
+	w := &WAL{
+		lg:        lg,
+		dir:       dirpath,
+		start:     snap,
+		decoder:   newDecoder(rs...),
+		readClose: closer,
+		locks:     ls,
+	}
+
+	if write {
+		// write reuses the file descriptors from read; don't close so
+		// WAL can append without dropping the file lock
+		w.readClose = nil
+		if _, _, err := parseWALName(filepath.Base(w.tail().Name())); err != nil {
+			closer()
+			return nil, err
+		}
+		w.fp = newFilePipeline(lg, w.dir, SegmentSizeBytes)
+	}
+
+	return w, nil
+}
+
+func selectWALFiles(lg *zap.Logger, dirpath string, snap walpb.Snapshot) ([]string, int, error) {
+	names, err := readWALNames(lg, dirpath)
+	if err != nil {
+		return nil, -1, err
+	}
+
+	nameIndex, ok := searchIndex(lg, names, snap.Index)
+	if !ok || !isValidSeq(lg, names[nameIndex:]) {
+		err = ErrFileNotFound
+		return nil, -1, err
+	}
+
+	return names, nameIndex, nil
+}
+
+func openWALFiles(lg *zap.Logger, dirpath string, names []string, nameIndex int, write bool) ([]io.Reader, []*fileutil.LockedFile, func() error, error) {
+	rcs := make([]io.ReadCloser, 0)
+	rs := make([]io.Reader, 0)
+	ls := make([]*fileutil.LockedFile, 0)
+	for _, name := range names[nameIndex:] {
+		p := filepath.Join(dirpath, name)
+		if write {
+			l, err := fileutil.TryLockFile(p, os.O_RDWR, fileutil.PrivateFileMode)
+			if err != nil {
+				closeAll(rcs...)
+				return nil, nil, nil, err
+			}
+			ls = append(ls, l)
+			rcs = append(rcs, l)
+		} else {
+			rf, err := os.OpenFile(p, os.O_RDONLY, fileutil.PrivateFileMode)
+			if err != nil {
+				closeAll(rcs...)
+				return nil, nil, nil, err
+			}
+			ls = append(ls, nil)
+			rcs = append(rcs, rf)
+		}
+		rs = append(rs, rcs[len(rcs)-1])
+	}
+
+	closer := func() error { return closeAll(rcs...) }
+
+	return rs, ls, closer, nil
+}
+
+// ReadAll reads out records of the current WAL.
+// If opened in write mode, it must read out all records until EOF. Or an error
+// will be returned.
+// If opened in read mode, it will try to read all records if possible.
+// If it cannot read out the expected snap, it will return ErrSnapshotNotFound.
+// If loaded snap doesn't match with the expected one, it will return
+// all the records and error ErrSnapshotMismatch.
+// TODO: detect not-last-snap error.
+// TODO: maybe loose the checking of match.
+// After ReadAll, the WAL will be ready for appending new records.
+func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.Entry, err error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	rec := &walpb.Record{}
+	decoder := w.decoder
+
+	var match bool
+	for err = decoder.decode(rec); err == nil; err = decoder.decode(rec) {
+		switch rec.Type {
+		case entryType:
+			e := mustUnmarshalEntry(rec.Data)
+			if e.Index > w.start.Index {
+				ents = append(ents[:e.Index-w.start.Index-1], e)
+			}
+			w.enti = e.Index
+
+		case stateType:
+			state = mustUnmarshalState(rec.Data)
+
+		case metadataType:
+			if metadata != nil && !bytes.Equal(metadata, rec.Data) {
+				state.Reset()
+				return nil, state, nil, ErrMetadataConflict
+			}
+			metadata = rec.Data
+
+		case crcType:
+			crc := decoder.crc.Sum32()
+			// current crc of decoder must match the crc of the record.
+			// do no need to match 0 crc, since the decoder is a new one at this case.
+			if crc != 0 && rec.Validate(crc) != nil {
+				state.Reset()
+				return nil, state, nil, ErrCRCMismatch
+			}
+			decoder.updateCRC(rec.Crc)
+
+		case snapshotType:
+			var snap walpb.Snapshot
+			pbutil.MustUnmarshal(&snap, rec.Data)
+			if snap.Index == w.start.Index {
+				if snap.Term != w.start.Term {
+					state.Reset()
+					return nil, state, nil, ErrSnapshotMismatch
+				}
+				match = true
+			}
+
+		default:
+			state.Reset()
+			return nil, state, nil, fmt.Errorf("unexpected block type %d", rec.Type)
+		}
+	}
+
+	switch w.tail() {
+	case nil:
+		// We do not have to read out all entries in read mode.
+		// The last record maybe a partial written one, so
+		// ErrunexpectedEOF might be returned.
+		if err != io.EOF && err != io.ErrUnexpectedEOF {
+			state.Reset()
+			return nil, state, nil, err
+		}
+	default:
+		// We must read all of the entries if WAL is opened in write mode.
+		if err != io.EOF {
+			state.Reset()
+			return nil, state, nil, err
+		}
+		// decodeRecord() will return io.EOF if it detects a zero record,
+		// but this zero record may be followed by non-zero records from
+		// a torn write. Overwriting some of these non-zero records, but
+		// not all, will cause CRC errors on WAL open. Since the records
+		// were never fully synced to disk in the first place, it's safe
+		// to zero them out to avoid any CRC errors from new writes.
+		if _, err = w.tail().Seek(w.decoder.lastOffset(), io.SeekStart); err != nil {
+			return nil, state, nil, err
+		}
+		if err = fileutil.ZeroToEnd(w.tail().File); err != nil {
+			return nil, state, nil, err
+		}
+	}
+
+	err = nil
+	if !match {
+		err = ErrSnapshotNotFound
+	}
+
+	// close decoder, disable reading
+	if w.readClose != nil {
+		w.readClose()
+		w.readClose = nil
+	}
+	w.start = walpb.Snapshot{}
+
+	w.metadata = metadata
+
+	if w.tail() != nil {
+		// create encoder (chain crc with the decoder), enable appending
+		w.encoder, err = newFileEncoder(w.tail().File, w.decoder.lastCRC())
+		if err != nil {
+			return
+		}
+	}
+	w.decoder = nil
+
+	return metadata, state, ents, err
+}
+
+// Verify reads through the given WAL and verifies that it is not corrupted.
+// It creates a new decoder to read through the records of the given WAL.
+// It does not conflict with any open WAL, but it is recommended not to
+// call this function after opening the WAL for writing.
+// If it cannot read out the expected snap, it will return ErrSnapshotNotFound.
+// If the loaded snap doesn't match with the expected one, it will
+// return error ErrSnapshotMismatch.
+func Verify(lg *zap.Logger, walDir string, snap walpb.Snapshot) error {
+	var metadata []byte
+	var err error
+	var match bool
+
+	rec := &walpb.Record{}
+
+	names, nameIndex, err := selectWALFiles(lg, walDir, snap)
+	if err != nil {
+		return err
+	}
+
+	// open wal files in read mode, so that there is no conflict
+	// when the same WAL is opened elsewhere in write mode
+	rs, _, closer, err := openWALFiles(lg, walDir, names, nameIndex, false)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if closer != nil {
+			closer()
+		}
+	}()
+
+	// create a new decoder from the readers on the WAL files
+	decoder := newDecoder(rs...)
+
+	for err = decoder.decode(rec); err == nil; err = decoder.decode(rec) {
+		switch rec.Type {
+		case metadataType:
+			if metadata != nil && !bytes.Equal(metadata, rec.Data) {
+				return ErrMetadataConflict
+			}
+			metadata = rec.Data
+		case crcType:
+			crc := decoder.crc.Sum32()
+			// Current crc of decoder must match the crc of the record.
+			// We need not match 0 crc, since the decoder is a new one at this point.
+			if crc != 0 && rec.Validate(crc) != nil {
+				return ErrCRCMismatch
+			}
+			decoder.updateCRC(rec.Crc)
+		case snapshotType:
+			var loadedSnap walpb.Snapshot
+			pbutil.MustUnmarshal(&loadedSnap, rec.Data)
+			if loadedSnap.Index == snap.Index {
+				if loadedSnap.Term != snap.Term {
+					return ErrSnapshotMismatch
+				}
+				match = true
+			}
+		// We ignore all entry and state type records as these
+		// are not necessary for validating the WAL contents
+		case entryType:
+		case stateType:
+		default:
+			return fmt.Errorf("unexpected block type %d", rec.Type)
+		}
+	}
+
+	// We do not have to read out all the WAL entries
+	// as the decoder is opened in read mode.
+	if err != io.EOF && err != io.ErrUnexpectedEOF {
+		return err
+	}
+
+	if !match {
+		return ErrSnapshotNotFound
+	}
+
+	return nil
+}
+
+// cut closes current file written and creates a new one ready to append.
+// cut first creates a temp wal file and writes necessary headers into it.
+// Then cut atomically rename temp wal file to a wal file.
+func (w *WAL) cut() error {
+	// close old wal file; truncate to avoid wasting space if an early cut
+	off, serr := w.tail().Seek(0, io.SeekCurrent)
+	if serr != nil {
+		return serr
+	}
+
+	if err := w.tail().Truncate(off); err != nil {
+		return err
+	}
+
+	if err := w.sync(); err != nil {
+		return err
+	}
+
+	fpath := filepath.Join(w.dir, walName(w.seq()+1, w.enti+1))
+
+	// create a temp wal file with name sequence + 1, or truncate the existing one
+	newTail, err := w.fp.Open()
+	if err != nil {
+		return err
+	}
+
+	// update writer and save the previous crc
+	w.locks = append(w.locks, newTail)
+	prevCrc := w.encoder.crc.Sum32()
+	w.encoder, err = newFileEncoder(w.tail().File, prevCrc)
+	if err != nil {
+		return err
+	}
+
+	if err = w.saveCrc(prevCrc); err != nil {
+		return err
+	}
+
+	if err = w.encoder.encode(&walpb.Record{Type: metadataType, Data: w.metadata}); err != nil {
+		return err
+	}
+
+	if err = w.saveState(&w.state); err != nil {
+		return err
+	}
+
+	// atomically move temp wal file to wal file
+	if err = w.sync(); err != nil {
+		return err
+	}
+
+	off, err = w.tail().Seek(0, io.SeekCurrent)
+	if err != nil {
+		return err
+	}
+
+	if err = os.Rename(newTail.Name(), fpath); err != nil {
+		return err
+	}
+	if err = fileutil.Fsync(w.dirFile); err != nil {
+		return err
+	}
+
+	// reopen newTail with its new path so calls to Name() match the wal filename format
+	newTail.Close()
+
+	if newTail, err = fileutil.LockFile(fpath, os.O_WRONLY, fileutil.PrivateFileMode); err != nil {
+		return err
+	}
+	if _, err = newTail.Seek(off, io.SeekStart); err != nil {
+		return err
+	}
+
+	w.locks[len(w.locks)-1] = newTail
+
+	prevCrc = w.encoder.crc.Sum32()
+	w.encoder, err = newFileEncoder(w.tail().File, prevCrc)
+	if err != nil {
+		return err
+	}
+
+	if w.lg != nil {
+		w.lg.Info("created a new WAL segment", zap.String("path", fpath))
+	} else {
+		plog.Infof("segmented wal file %v is created", fpath)
+	}
+	return nil
+}
+
+func (w *WAL) sync() error {
+	if w.encoder != nil {
+		if err := w.encoder.flush(); err != nil {
+			return err
+		}
+	}
+	start := time.Now()
+	err := fileutil.Fdatasync(w.tail().File)
+
+	took := time.Since(start)
+	if took > warnSyncDuration {
+		if w.lg != nil {
+			w.lg.Warn(
+				"slow fdatasync",
+				zap.Duration("took", took),
+				zap.Duration("expected-duration", warnSyncDuration),
+			)
+		} else {
+			plog.Warningf("sync duration of %v, expected less than %v", took, warnSyncDuration)
+		}
+	}
+	walFsyncSec.Observe(took.Seconds())
+
+	return err
+}
+
+// ReleaseLockTo releases the locks, which has smaller index than the given index
+// except the largest one among them.
+// For example, if WAL is holding lock 1,2,3,4,5,6, ReleaseLockTo(4) will release
+// lock 1,2 but keep 3. ReleaseLockTo(5) will release 1,2,3 but keep 4.
+func (w *WAL) ReleaseLockTo(index uint64) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if len(w.locks) == 0 {
+		return nil
+	}
+
+	var smaller int
+	found := false
+	for i, l := range w.locks {
+		_, lockIndex, err := parseWALName(filepath.Base(l.Name()))
+		if err != nil {
+			return err
+		}
+		if lockIndex >= index {
+			smaller = i - 1
+			found = true
+			break
+		}
+	}
+
+	// if no lock index is greater than the release index, we can
+	// release lock up to the last one(excluding).
+	if !found {
+		smaller = len(w.locks) - 1
+	}
+
+	if smaller <= 0 {
+		return nil
+	}
+
+	for i := 0; i < smaller; i++ {
+		if w.locks[i] == nil {
+			continue
+		}
+		w.locks[i].Close()
+	}
+	w.locks = w.locks[smaller:]
+
+	return nil
+}
+
+// Close closes the current WAL file and directory.
+func (w *WAL) Close() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.fp != nil {
+		w.fp.Close()
+		w.fp = nil
+	}
+
+	if w.tail() != nil {
+		if err := w.sync(); err != nil {
+			return err
+		}
+	}
+	for _, l := range w.locks {
+		if l == nil {
+			continue
+		}
+		if err := l.Close(); err != nil {
+			if w.lg != nil {
+				w.lg.Warn("failed to close WAL", zap.Error(err))
+			} else {
+				plog.Errorf("failed to unlock during closing wal: %s", err)
+			}
+		}
+	}
+
+	return w.dirFile.Close()
+}
+
+func (w *WAL) saveEntry(e *raftpb.Entry) error {
+	// TODO: add MustMarshalTo to reduce one allocation.
+	b := pbutil.MustMarshal(e)
+	rec := &walpb.Record{Type: entryType, Data: b}
+	if err := w.encoder.encode(rec); err != nil {
+		return err
+	}
+	w.enti = e.Index
+	return nil
+}
+
+func (w *WAL) saveState(s *raftpb.HardState) error {
+	if raft.IsEmptyHardState(*s) {
+		return nil
+	}
+	w.state = *s
+	b := pbutil.MustMarshal(s)
+	rec := &walpb.Record{Type: stateType, Data: b}
+	return w.encoder.encode(rec)
+}
+
+func (w *WAL) Save(st raftpb.HardState, ents []raftpb.Entry) error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	// short cut, do not call sync
+	if raft.IsEmptyHardState(st) && len(ents) == 0 {
+		return nil
+	}
+
+	mustSync := raft.MustSync(st, w.state, len(ents))
+
+	// TODO(xiangli): no more reference operator
+	for i := range ents {
+		if err := w.saveEntry(&ents[i]); err != nil {
+			return err
+		}
+	}
+	if err := w.saveState(&st); err != nil {
+		return err
+	}
+
+	curOff, err := w.tail().Seek(0, io.SeekCurrent)
+	if err != nil {
+		return err
+	}
+	if curOff < SegmentSizeBytes {
+		if mustSync {
+			return w.sync()
+		}
+		return nil
+	}
+
+	return w.cut()
+}
+
+func (w *WAL) SaveSnapshot(e walpb.Snapshot) error {
+	b := pbutil.MustMarshal(&e)
+
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	rec := &walpb.Record{Type: snapshotType, Data: b}
+	if err := w.encoder.encode(rec); err != nil {
+		return err
+	}
+	// update enti only when snapshot is ahead of last index
+	if w.enti < e.Index {
+		w.enti = e.Index
+	}
+	return w.sync()
+}
+
+func (w *WAL) saveCrc(prevCrc uint32) error {
+	return w.encoder.encode(&walpb.Record{Type: crcType, Crc: prevCrc})
+}
+
+func (w *WAL) tail() *fileutil.LockedFile {
+	if len(w.locks) > 0 {
+		return w.locks[len(w.locks)-1]
+	}
+	return nil
+}
+
+func (w *WAL) seq() uint64 {
+	t := w.tail()
+	if t == nil {
+		return 0
+	}
+	seq, _, err := parseWALName(filepath.Base(t.Name()))
+	if err != nil {
+		if w.lg != nil {
+			w.lg.Fatal("failed to parse WAL name", zap.String("name", t.Name()), zap.Error(err))
+		} else {
+			plog.Fatalf("bad wal name %s (%v)", t.Name(), err)
+		}
+	}
+	return seq
+}
+
+func closeAll(rcs ...io.ReadCloser) error {
+	for _, f := range rcs {
+		if err := f.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/vendor/go.etcd.io/etcd/wal/walpb/record.go b/vendor/go.etcd.io/etcd/wal/walpb/record.go
new file mode 100644
index 0000000..30a05e0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/walpb/record.go
@@ -0,0 +1,29 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package walpb
+
+import "errors"
+
+var (
+	ErrCRCMismatch = errors.New("walpb: crc mismatch")
+)
+
+func (rec *Record) Validate(crc uint32) error {
+	if rec.Crc == crc {
+		return nil
+	}
+	rec.Reset()
+	return ErrCRCMismatch
+}
diff --git a/vendor/go.etcd.io/etcd/wal/walpb/record.pb.go b/vendor/go.etcd.io/etcd/wal/walpb/record.pb.go
new file mode 100644
index 0000000..3ce63dd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/walpb/record.pb.go
@@ -0,0 +1,504 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: record.proto
+
+/*
+	Package walpb is a generated protocol buffer package.
+
+	It is generated from these files:
+		record.proto
+
+	It has these top-level messages:
+		Record
+		Snapshot
+*/
+package walpb
+
+import (
+	"fmt"
+
+	proto "github.com/golang/protobuf/proto"
+
+	math "math"
+
+	_ "github.com/gogo/protobuf/gogoproto"
+
+	io "io"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+
+type Record struct {
+	Type             int64  `protobuf:"varint,1,opt,name=type" json:"type"`
+	Crc              uint32 `protobuf:"varint,2,opt,name=crc" json:"crc"`
+	Data             []byte `protobuf:"bytes,3,opt,name=data" json:"data,omitempty"`
+	XXX_unrecognized []byte `json:"-"`
+}
+
+func (m *Record) Reset()                    { *m = Record{} }
+func (m *Record) String() string            { return proto.CompactTextString(m) }
+func (*Record) ProtoMessage()               {}
+func (*Record) Descriptor() ([]byte, []int) { return fileDescriptorRecord, []int{0} }
+
+type Snapshot struct {
+	Index            uint64 `protobuf:"varint,1,opt,name=index" json:"index"`
+	Term             uint64 `protobuf:"varint,2,opt,name=term" json:"term"`
+	XXX_unrecognized []byte `json:"-"`
+}
+
+func (m *Snapshot) Reset()                    { *m = Snapshot{} }
+func (m *Snapshot) String() string            { return proto.CompactTextString(m) }
+func (*Snapshot) ProtoMessage()               {}
+func (*Snapshot) Descriptor() ([]byte, []int) { return fileDescriptorRecord, []int{1} }
+
+func init() {
+	proto.RegisterType((*Record)(nil), "walpb.Record")
+	proto.RegisterType((*Snapshot)(nil), "walpb.Snapshot")
+}
+func (m *Record) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Record) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	dAtA[i] = 0x8
+	i++
+	i = encodeVarintRecord(dAtA, i, uint64(m.Type))
+	dAtA[i] = 0x10
+	i++
+	i = encodeVarintRecord(dAtA, i, uint64(m.Crc))
+	if m.Data != nil {
+		dAtA[i] = 0x1a
+		i++
+		i = encodeVarintRecord(dAtA, i, uint64(len(m.Data)))
+		i += copy(dAtA[i:], m.Data)
+	}
+	if m.XXX_unrecognized != nil {
+		i += copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	return i, nil
+}
+
+func (m *Snapshot) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalTo(dAtA)
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *Snapshot) MarshalTo(dAtA []byte) (int, error) {
+	var i int
+	_ = i
+	var l int
+	_ = l
+	dAtA[i] = 0x8
+	i++
+	i = encodeVarintRecord(dAtA, i, uint64(m.Index))
+	dAtA[i] = 0x10
+	i++
+	i = encodeVarintRecord(dAtA, i, uint64(m.Term))
+	if m.XXX_unrecognized != nil {
+		i += copy(dAtA[i:], m.XXX_unrecognized)
+	}
+	return i, nil
+}
+
+func encodeVarintRecord(dAtA []byte, offset int, v uint64) int {
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return offset + 1
+}
+func (m *Record) Size() (n int) {
+	var l int
+	_ = l
+	n += 1 + sovRecord(uint64(m.Type))
+	n += 1 + sovRecord(uint64(m.Crc))
+	if m.Data != nil {
+		l = len(m.Data)
+		n += 1 + l + sovRecord(uint64(l))
+	}
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func (m *Snapshot) Size() (n int) {
+	var l int
+	_ = l
+	n += 1 + sovRecord(uint64(m.Index))
+	n += 1 + sovRecord(uint64(m.Term))
+	if m.XXX_unrecognized != nil {
+		n += len(m.XXX_unrecognized)
+	}
+	return n
+}
+
+func sovRecord(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+func sozRecord(x uint64) (n int) {
+	return sovRecord(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *Record) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowRecord
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: Record: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Record: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Type", wireType)
+			}
+			m.Type = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Type |= (int64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Crc", wireType)
+			}
+			m.Crc = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Crc |= (uint32(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 3:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Data", wireType)
+			}
+			var byteLen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				byteLen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if byteLen < 0 {
+				return ErrInvalidLengthRecord
+			}
+			postIndex := iNdEx + byteLen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Data = append(m.Data[:0], dAtA[iNdEx:postIndex]...)
+			if m.Data == nil {
+				m.Data = []byte{}
+			}
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipRecord(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthRecord
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func (m *Snapshot) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowRecord
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: Snapshot: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: Snapshot: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Index", wireType)
+			}
+			m.Index = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Index |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		case 2:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Term", wireType)
+			}
+			m.Term = 0
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				m.Term |= (uint64(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+		default:
+			iNdEx = preIndex
+			skippy, err := skipRecord(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if skippy < 0 {
+				return ErrInvalidLengthRecord
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.XXX_unrecognized = append(m.XXX_unrecognized, dAtA[iNdEx:iNdEx+skippy]...)
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipRecord(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowRecord
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+			return iNdEx, nil
+		case 1:
+			iNdEx += 8
+			return iNdEx, nil
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowRecord
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			iNdEx += length
+			if length < 0 {
+				return 0, ErrInvalidLengthRecord
+			}
+			return iNdEx, nil
+		case 3:
+			for {
+				var innerWire uint64
+				var start int = iNdEx
+				for shift := uint(0); ; shift += 7 {
+					if shift >= 64 {
+						return 0, ErrIntOverflowRecord
+					}
+					if iNdEx >= l {
+						return 0, io.ErrUnexpectedEOF
+					}
+					b := dAtA[iNdEx]
+					iNdEx++
+					innerWire |= (uint64(b) & 0x7F) << shift
+					if b < 0x80 {
+						break
+					}
+				}
+				innerWireType := int(innerWire & 0x7)
+				if innerWireType == 4 {
+					break
+				}
+				next, err := skipRecord(dAtA[start:])
+				if err != nil {
+					return 0, err
+				}
+				iNdEx = start + next
+			}
+			return iNdEx, nil
+		case 4:
+			return iNdEx, nil
+		case 5:
+			iNdEx += 4
+			return iNdEx, nil
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+	}
+	panic("unreachable")
+}
+
+var (
+	ErrInvalidLengthRecord = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowRecord   = fmt.Errorf("proto: integer overflow")
+)
+
+func init() { proto.RegisterFile("record.proto", fileDescriptorRecord) }
+
+var fileDescriptorRecord = []byte{
+	// 186 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xe2, 0x29, 0x4a, 0x4d, 0xce,
+	0x2f, 0x4a, 0xd1, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x62, 0x2d, 0x4f, 0xcc, 0x29, 0x48, 0x92,
+	0x12, 0x49, 0xcf, 0x4f, 0xcf, 0x07, 0x8b, 0xe8, 0x83, 0x58, 0x10, 0x49, 0x25, 0x3f, 0x2e, 0xb6,
+	0x20, 0xb0, 0x62, 0x21, 0x09, 0x2e, 0x96, 0x92, 0xca, 0x82, 0x54, 0x09, 0x46, 0x05, 0x46, 0x0d,
+	0x66, 0x27, 0x96, 0x13, 0xf7, 0xe4, 0x19, 0x82, 0xc0, 0x22, 0x42, 0x62, 0x5c, 0xcc, 0xc9, 0x45,
+	0xc9, 0x12, 0x4c, 0x0a, 0x8c, 0x1a, 0xbc, 0x50, 0x09, 0x90, 0x80, 0x90, 0x10, 0x17, 0x4b, 0x4a,
+	0x62, 0x49, 0xa2, 0x04, 0xb3, 0x02, 0xa3, 0x06, 0x4f, 0x10, 0x98, 0xad, 0xe4, 0xc0, 0xc5, 0x11,
+	0x9c, 0x97, 0x58, 0x50, 0x9c, 0x91, 0x5f, 0x22, 0x24, 0xc5, 0xc5, 0x9a, 0x99, 0x97, 0x92, 0x5a,
+	0x01, 0x36, 0x92, 0x05, 0xaa, 0x13, 0x22, 0x04, 0xb6, 0x2d, 0xb5, 0x28, 0x17, 0x6c, 0x28, 0x0b,
+	0xdc, 0xb6, 0xd4, 0xa2, 0x5c, 0x27, 0x91, 0x13, 0x0f, 0xe5, 0x18, 0x4e, 0x3c, 0x92, 0x63, 0xbc,
+	0xf0, 0x48, 0x8e, 0xf1, 0xc1, 0x23, 0x39, 0xc6, 0x19, 0x8f, 0xe5, 0x18, 0x00, 0x01, 0x00, 0x00,
+	0xff, 0xff, 0x7f, 0x5e, 0x5c, 0x46, 0xd3, 0x00, 0x00, 0x00,
+}
diff --git a/vendor/go.etcd.io/etcd/wal/walpb/record.proto b/vendor/go.etcd.io/etcd/wal/walpb/record.proto
new file mode 100644
index 0000000..b694cb2
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/wal/walpb/record.proto
@@ -0,0 +1,20 @@
+syntax = "proto2";
+package walpb;
+
+import "gogoproto/gogo.proto";
+
+option (gogoproto.marshaler_all) = true;
+option (gogoproto.sizer_all) = true;
+option (gogoproto.unmarshaler_all) = true;
+option (gogoproto.goproto_getters_all) = false;
+
+message Record {
+	optional int64 type  = 1 [(gogoproto.nullable) = false];
+	optional uint32 crc  = 2 [(gogoproto.nullable) = false];
+	optional bytes data  = 3;
+}
+
+message Snapshot {
+	optional uint64 index = 1 [(gogoproto.nullable) = false];
+	optional uint64 term  = 2 [(gogoproto.nullable) = false];
+}