diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.gitignore b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.gitignore
new file mode 100644
index 0000000..826caa3
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.gitignore
@@ -0,0 +1,204 @@
+# Created by .ignore support plugin (hsz.mobi)
+### Go template
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+### Windows template
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+### Kate template
+# Swap Files #
+.*.kate-swp
+.swp.*
+### SublimeText template
+# cache files for sublime text
+*.tmlanguage.cache
+*.tmPreferences.cache
+*.stTheme.cache
+
+# workspace files are user-specific
+*.sublime-workspace
+
+# project files should be checked into the repository, unless a significant
+# proportion of contributors will probably not be using SublimeText
+# *.sublime-project
+
+# sftp configuration file
+sftp-config.json
+### Linux template
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+### JetBrains template
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff:
+.idea
+.idea/tasks.xml
+.idea/dictionaries
+.idea/vcs.xml
+.idea/jsLibraryMappings.xml
+
+# Sensitive or high-churn files:
+.idea/dataSources.ids
+.idea/dataSources.xml
+.idea/dataSources.local.xml
+.idea/sqlDataSources.xml
+.idea/dynamic.xml
+.idea/uiDesigner.xml
+
+# Gradle:
+.idea/gradle.xml
+.idea/libraries
+
+# Mongo Explorer plugin:
+.idea/mongoSettings.xml
+
+## File-based project format:
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+/out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+### Xcode template
+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## Build generated
+build/
+DerivedData/
+
+## Various settings
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+xcuserdata/
+
+## Other
+*.moved-aside
+*.xccheckout
+*.xcscmblueprint
+### Eclipse template
+
+.metadata
+bin/
+tmp/
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.settings/
+.loadpath
+.recommenders
+
+# Eclipse Core
+.project
+
+# External tool builders
+.externalToolBuilders/
+
+# Locally stored "Eclipse launch configurations"
+*.launch
+
+# PyDev specific (Python IDE for Eclipse)
+*.pydevproject
+
+# CDT-specific (C/C++ Development Tooling)
+.cproject
+
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+
+# Java annotation processor (APT)
+.factorypath
+
+# PDT-specific (PHP Development Tools)
+.buildpath
+
+# sbteclipse plugin
+.target
+
+# Tern plugin
+.tern-project
+
+# TeXlipse plugin
+.texlipse
+
+# STS (Spring Tool Suite)
+.springBeans
+
+# Code Recommenders
+.recommenders/
+
+
+coverage.txt
+
+#vendor
+vendor/
+
+.envrc
\ No newline at end of file
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.travis.yml b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.travis.yml
new file mode 100644
index 0000000..fc198d8
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.travis.yml
@@ -0,0 +1,16 @@
+sudo: false
+language: go
+go:
+  - 1.13.x
+  - 1.14.x
+  - 1.15.x
+
+env:
+  global:
+    - GO111MODULE=on
+
+script:
+ - make test
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CHANGELOG.md b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CHANGELOG.md
new file mode 100644
index 0000000..6eeb7e2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CHANGELOG.md
@@ -0,0 +1,51 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+
+Types of changes:
+- `Added` for new features.
+- `Changed` for changes in existing functionality.
+- `Deprecated` for soon-to-be removed features.
+- `Removed` for now removed features.
+- `Fixed` for any bug fixes.
+- `Security` in case of vulnerabilities.
+
+## [Unreleased]
+
+### Added
+
+- [#223](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/223) Add go-kit logging middleware - [adrien-f](https://github.com/adrien-f)
+
+## [v1.1.0] - 2019-09-12
+### Added
+- [#226](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/226) Support for go modules.
+- [#221](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/221) logging/zap add support for gRPC LoggerV2  - [kush-patel-hs](https://github.com/kush-patel-hs)
+- [#181](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/181) Rate Limit support - [ceshihao](https://github.com/ceshihao)
+- [#161](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/161) Retry on server stream call - [lonnblad](https://github.com/lonnblad)
+- [#152](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/152) Exponential backoff functions - [polyfloyd](https://github.com/polyfloyd)
+- [#147](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/147) Jaeger support for ctxtags extraction - [vporoshok](https://github.com/vporoshok)
+- [#184](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/184) ctxTags identifies if the call was sampled
+
+### Deprecated
+- [#201](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/201) `golang.org/x/net/context` - [houz42](https://github.com/houz42)
+- [#183](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/183) Documentation Generation in favour of <godoc.org>.
+
+### Fixed
+- [172](https://github.com/grpc-ecosystem/go-grpc-middleware/pull/172) Passing ctx into retry and recover - [johanbrandhorst](https://github.com/johanbrandhorst)
+- Numerious documentation fixes.
+
+## v1.0.0 - 2018-05-08
+### Added
+- grpc_auth 
+- grpc_ctxtags
+- grpc_zap
+- grpc_logrus
+- grpc_opentracing
+- grpc_retry
+- grpc_validator
+- grpc_recovery
+
+[Unreleased]: https://github.com/grpc-ecosystem/go-grpc-middleware/compare/v1.1.0...HEAD 
+[v1.1.0]: https://github.com/grpc-ecosystem/go-grpc-middleware/compare/v1.0.0...v1.1.0 
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CONTRIBUTING.md b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CONTRIBUTING.md
new file mode 100644
index 0000000..dd52ab8
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CONTRIBUTING.md
@@ -0,0 +1,20 @@
+# Contributing
+
+We would love to have people submit pull requests and help make `grpc-ecosystem/go-grpc-middleware` even better 👍.
+
+Fork, then clone the repo:
+
+```bash
+git clone git@github.com:your-username/go-grpc-middleware.git
+```    
+
+Before checking in please run the following:
+
+```bash
+make all
+```
+
+This will `vet`, `fmt`, regenerate documentation and run all tests.
+
+
+Push to your fork and open a pull request.
\ No newline at end of file
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/LICENSE b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/LICENSE
new file mode 100644
index 0000000..b2b0650
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/LICENSE
@@ -0,0 +1,201 @@
+                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+      any Contribution intentionally submitted for inclusion in the Work
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+      this License, without any additional terms or conditions.
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+      the terms of any separate license agreement you may have executed
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+
+   6. Trademarks. This License does not grant permission to use the trade
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+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+      file or class name and description of purpose be included on the
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+   Copyright [yyyy] [name of copyright owner]
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+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
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\ No newline at end of file
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/README.md b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/README.md
new file mode 100644
index 0000000..814e155
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/README.md
@@ -0,0 +1,86 @@
+# Go gRPC Middleware
+
+[![Travis Build](https://travis-ci.org/grpc-ecosystem/go-grpc-middleware.svg?branch=master)](https://travis-ci.org/grpc-ecosystem/go-grpc-middleware)
+[![Go Report Card](https://goreportcard.com/badge/github.com/grpc-ecosystem/go-grpc-middleware)](https://goreportcard.com/report/github.com/grpc-ecosystem/go-grpc-middleware)
+[![GoDoc](http://img.shields.io/badge/GoDoc-Reference-blue.svg)](https://godoc.org/github.com/grpc-ecosystem/go-grpc-middleware)
+[![SourceGraph](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-middleware/-/badge.svg)](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-middleware/?badge)
+[![codecov](https://codecov.io/gh/grpc-ecosystem/go-grpc-middleware/branch/master/graph/badge.svg)](https://codecov.io/gh/grpc-ecosystem/go-grpc-middleware)
+[![Apache 2.0 License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE)
+[![quality: production](https://img.shields.io/badge/quality-production-orange.svg)](#status)
+[![Slack](https://img.shields.io/badge/slack-%23grpc--middleware-brightgreen)](https://slack.com/share/IRUQCFC23/9Tm7hxRFVKKNoajQfMOcUiIk/enQtODc4ODI4NTIyMDcxLWM5NDA0ZTE4Njg5YjRjYWZkMTI5MzQwNDY3YzBjMzE1YzdjOGM5ZjI1NDNiM2JmNzI2YjM5ODE5OTRiNTEyOWE)
+
+[gRPC Go](https://github.com/grpc/grpc-go) Middleware: interceptors, helpers, utilities.
+
+## Middleware
+
+[gRPC Go](https://github.com/grpc/grpc-go) recently acquired support for
+Interceptors, i.e. [middleware](https://medium.com/@matryer/writing-middleware-in-golang-and-how-go-makes-it-so-much-fun-4375c1246e81#.gv7tdlghs) 
+that is executed either on the gRPC Server before the request is passed onto the user's application logic, or on the gRPC client around the user call. It is a perfect way to implement
+common patterns: auth, logging, message, validation, retries or monitoring.
+
+These are generic building blocks that make it easy to build multiple microservices easily.
+The purpose of this repository is to act as a go-to point for such reusable functionality. It contains
+some of them itself, but also will link to useful external repos.
+
+`grpc_middleware` itself provides support for chaining interceptors, here's an example:
+
+```go
+import "github.com/grpc-ecosystem/go-grpc-middleware"
+
+myServer := grpc.NewServer(
+    grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
+        grpc_recovery.StreamServerInterceptor(),
+        grpc_ctxtags.StreamServerInterceptor(),
+        grpc_opentracing.StreamServerInterceptor(),
+        grpc_prometheus.StreamServerInterceptor,
+        grpc_zap.StreamServerInterceptor(zapLogger),
+        grpc_auth.StreamServerInterceptor(myAuthFunction),
+    )),
+    grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
+        grpc_recovery.UnaryServerInterceptor(),
+        grpc_ctxtags.UnaryServerInterceptor(),
+        grpc_opentracing.UnaryServerInterceptor(),
+        grpc_prometheus.UnaryServerInterceptor,
+        grpc_zap.UnaryServerInterceptor(zapLogger),
+        grpc_auth.UnaryServerInterceptor(myAuthFunction),
+    )),
+)
+```
+
+## Interceptors
+
+*Please send a PR to add new interceptors or middleware to this list*
+
+#### Auth
+   * [`grpc_auth`](auth) - a customizable (via `AuthFunc`) piece of auth middleware 
+
+#### Logging
+   * [`grpc_ctxtags`](tags/) - a library that adds a `Tag` map to context, with data populated from request body
+   * [`grpc_zap`](logging/zap/) - integration of [zap](https://github.com/uber-go/zap) logging library into gRPC handlers.
+   * [`grpc_logrus`](logging/logrus/) - integration of [logrus](https://github.com/sirupsen/logrus) logging library into gRPC handlers.
+   * [`grpc_kit`](logging/kit/) - integration of [go-kit](https://github.com/go-kit/kit/tree/master/log) logging library into gRPC handlers.
+   * [`grpc_grpc_logsettable`](logging/settable/) - a wrapper around `grpclog.LoggerV2` that allows to replace loggers in runtime (thread-safe).
+
+#### Monitoring
+   * [`grpc_prometheus`⚡](https://github.com/grpc-ecosystem/go-grpc-prometheus) - Prometheus client-side and server-side monitoring middleware
+   * [`otgrpc`⚡](https://github.com/grpc-ecosystem/grpc-opentracing/tree/master/go/otgrpc) - [OpenTracing](http://opentracing.io/) client-side and server-side interceptors
+   * [`grpc_opentracing`](tracing/opentracing) - [OpenTracing](http://opentracing.io/) client-side and server-side interceptors with support for streaming and handler-returned tags
+
+#### Client
+   * [`grpc_retry`](retry/) - a generic gRPC response code retry mechanism, client-side middleware
+
+#### Server
+   * [`grpc_validator`](validator/) - codegen inbound message validation from `.proto` options
+   * [`grpc_recovery`](recovery/) - turn panics into gRPC errors
+   * [`ratelimit`](ratelimit/) - grpc rate limiting by your own limiter
+
+
+## Status
+
+This code has been running in *production* since May 2016 as the basis of the gRPC micro services stack at [Improbable](https://improbable.io).
+
+Additional tooling will be added, and contributions are welcome.
+
+## License
+
+`go-grpc-middleware` is released under the Apache 2.0 license. See the [LICENSE](LICENSE) file for details.
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go
new file mode 100644
index 0000000..ea3738b
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go
@@ -0,0 +1,120 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+// gRPC Server Interceptor chaining middleware.
+
+package grpc_middleware
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+)
+
+// ChainUnaryServer creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryServer(one, two, three) will execute one before two before three, and three
+// will see context changes of one and two.
+func ChainUnaryServer(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor {
+	n := len(interceptors)
+
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		chainer := func(currentInter grpc.UnaryServerInterceptor, currentHandler grpc.UnaryHandler) grpc.UnaryHandler {
+			return func(currentCtx context.Context, currentReq interface{}) (interface{}, error) {
+				return currentInter(currentCtx, currentReq, info, currentHandler)
+			}
+		}
+
+		chainedHandler := handler
+		for i := n - 1; i >= 0; i-- {
+			chainedHandler = chainer(interceptors[i], chainedHandler)
+		}
+
+		return chainedHandler(ctx, req)
+	}
+}
+
+// ChainStreamServer creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryServer(one, two, three) will execute one before two before three.
+// If you want to pass context between interceptors, use WrapServerStream.
+func ChainStreamServer(interceptors ...grpc.StreamServerInterceptor) grpc.StreamServerInterceptor {
+	n := len(interceptors)
+
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		chainer := func(currentInter grpc.StreamServerInterceptor, currentHandler grpc.StreamHandler) grpc.StreamHandler {
+			return func(currentSrv interface{}, currentStream grpc.ServerStream) error {
+				return currentInter(currentSrv, currentStream, info, currentHandler)
+			}
+		}
+
+		chainedHandler := handler
+		for i := n - 1; i >= 0; i-- {
+			chainedHandler = chainer(interceptors[i], chainedHandler)
+		}
+
+		return chainedHandler(srv, ss)
+	}
+}
+
+// ChainUnaryClient creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainUnaryClient(one, two, three) will execute one before two before three.
+func ChainUnaryClient(interceptors ...grpc.UnaryClientInterceptor) grpc.UnaryClientInterceptor {
+	n := len(interceptors)
+
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		chainer := func(currentInter grpc.UnaryClientInterceptor, currentInvoker grpc.UnaryInvoker) grpc.UnaryInvoker {
+			return func(currentCtx context.Context, currentMethod string, currentReq, currentRepl interface{}, currentConn *grpc.ClientConn, currentOpts ...grpc.CallOption) error {
+				return currentInter(currentCtx, currentMethod, currentReq, currentRepl, currentConn, currentInvoker, currentOpts...)
+			}
+		}
+
+		chainedInvoker := invoker
+		for i := n - 1; i >= 0; i-- {
+			chainedInvoker = chainer(interceptors[i], chainedInvoker)
+		}
+
+		return chainedInvoker(ctx, method, req, reply, cc, opts...)
+	}
+}
+
+// ChainStreamClient creates a single interceptor out of a chain of many interceptors.
+//
+// Execution is done in left-to-right order, including passing of context.
+// For example ChainStreamClient(one, two, three) will execute one before two before three.
+func ChainStreamClient(interceptors ...grpc.StreamClientInterceptor) grpc.StreamClientInterceptor {
+	n := len(interceptors)
+
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		chainer := func(currentInter grpc.StreamClientInterceptor, currentStreamer grpc.Streamer) grpc.Streamer {
+			return func(currentCtx context.Context, currentDesc *grpc.StreamDesc, currentConn *grpc.ClientConn, currentMethod string, currentOpts ...grpc.CallOption) (grpc.ClientStream, error) {
+				return currentInter(currentCtx, currentDesc, currentConn, currentMethod, currentStreamer, currentOpts...)
+			}
+		}
+
+		chainedStreamer := streamer
+		for i := n - 1; i >= 0; i-- {
+			chainedStreamer = chainer(interceptors[i], chainedStreamer)
+		}
+
+		return chainedStreamer(ctx, desc, cc, method, opts...)
+	}
+}
+
+// Chain creates a single interceptor out of a chain of many interceptors.
+//
+// WithUnaryServerChain is a grpc.Server config option that accepts multiple unary interceptors.
+// Basically syntactic sugar.
+func WithUnaryServerChain(interceptors ...grpc.UnaryServerInterceptor) grpc.ServerOption {
+	return grpc.UnaryInterceptor(ChainUnaryServer(interceptors...))
+}
+
+// WithStreamServerChain is a grpc.Server config option that accepts multiple stream interceptors.
+// Basically syntactic sugar.
+func WithStreamServerChain(interceptors ...grpc.StreamServerInterceptor) grpc.ServerOption {
+	return grpc.StreamInterceptor(ChainStreamServer(interceptors...))
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/doc.go
new file mode 100644
index 0000000..718e100
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/doc.go
@@ -0,0 +1,69 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+`grpc_middleware` is a collection of gRPC middleware packages: interceptors, helpers and tools.
+
+Middleware
+
+gRPC is a fantastic RPC middleware, which sees a lot of adoption in the Golang world. However, the
+upstream gRPC codebase is relatively bare bones.
+
+This package, and most of its child packages provides commonly needed middleware for gRPC:
+client-side interceptors for retires, server-side interceptors for input validation and auth,
+functions for chaining said interceptors, metadata convenience methods and more.
+
+Chaining
+
+By default, gRPC doesn't allow one to have more than one interceptor either on the client nor on
+the server side. `grpc_middleware` provides convenient chaining methods
+
+Simple way of turning a multiple interceptors into a single interceptor. Here's an example for
+server chaining:
+
+	myServer := grpc.NewServer(
+	    grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(loggingStream, monitoringStream, authStream)),
+	    grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(loggingUnary, monitoringUnary, authUnary)),
+	)
+
+These interceptors will be executed from left to right: logging, monitoring and auth.
+
+Here's an example for client side chaining:
+
+	clientConn, err = grpc.Dial(
+	    address,
+	        grpc.WithUnaryInterceptor(grpc_middleware.ChainUnaryClient(monitoringClientUnary, retryUnary)),
+	        grpc.WithStreamInterceptor(grpc_middleware.ChainStreamClient(monitoringClientStream, retryStream)),
+	)
+	client = pb_testproto.NewTestServiceClient(clientConn)
+	resp, err := client.PingEmpty(s.ctx, &myservice.Request{Msg: "hello"})
+
+These interceptors will be executed from left to right: monitoring and then retry logic.
+
+The retry interceptor will call every interceptor that follows it whenever when a retry happens.
+
+Writing Your Own
+
+Implementing your own interceptor is pretty trivial: there are interfaces for that. But the interesting
+bit exposing common data to handlers (and other middleware), similarly to HTTP Middleware design.
+For example, you may want to pass the identity of the caller from the auth interceptor all the way
+to the handling function.
+
+For example, a client side interceptor example for auth looks like:
+
+	func FakeAuthUnaryInterceptor(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+	   newCtx := context.WithValue(ctx, "user_id", "john@example.com")
+	   return handler(newCtx, req)
+	}
+
+Unfortunately, it's not as easy for streaming RPCs. These have the `context.Context` embedded within
+the `grpc.ServerStream` object. To pass values through context, a wrapper (`WrappedServerStream`) is
+needed. For example:
+
+	func FakeAuthStreamingInterceptor(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+	   newStream := grpc_middleware.WrapServerStream(stream)
+	   newStream.WrappedContext = context.WithValue(ctx, "user_id", "john@example.com")
+	   return handler(srv, newStream)
+	}
+*/
+package grpc_middleware
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.mod b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.mod
new file mode 100644
index 0000000..7dc62e5
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.mod
@@ -0,0 +1,22 @@
+module github.com/grpc-ecosystem/go-grpc-middleware
+
+require (
+	github.com/go-kit/kit v0.9.0
+	github.com/go-logfmt/logfmt v0.4.0 // indirect
+	github.com/go-stack/stack v1.8.0 // indirect
+	github.com/gogo/protobuf v1.3.2
+	github.com/golang/protobuf v1.3.3
+	github.com/opentracing/opentracing-go v1.1.0
+	github.com/pkg/errors v0.8.1 // indirect
+	github.com/sirupsen/logrus v1.4.2
+	github.com/stretchr/testify v1.4.0
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.10.0
+	golang.org/x/net v0.0.0-20201021035429-f5854403a974
+	golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be
+	google.golang.org/genproto v0.0.0-20200423170343-7949de9c1215 // indirect
+	google.golang.org/grpc v1.29.1
+)
+
+go 1.14
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.sum b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.sum
new file mode 100644
index 0000000..ee522cd
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/go.sum
@@ -0,0 +1,122 @@
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diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/makefile b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/makefile
new file mode 100644
index 0000000..b18d2d2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/makefile
@@ -0,0 +1,17 @@
+SHELL=/bin/bash
+
+GOFILES_NOVENDOR = $(shell go list ./... | grep -v /vendor/)
+
+all: vet fmt test
+
+fmt:
+	go fmt $(GOFILES_NOVENDOR)
+
+vet:
+	# do not check lostcancel, they are intentional.
+	go vet -lostcancel=false $(GOFILES_NOVENDOR)
+
+test: vet
+	./scripts/test_all.sh
+
+.PHONY: all test
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/slack.png b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/slack.png
new file mode 100644
index 0000000..cc8f9a6
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/slack.png
Binary files differ
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go
new file mode 100644
index 0000000..0da1658
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/context.go
@@ -0,0 +1,78 @@
+package grpc_ctxtags
+
+import (
+	"context"
+)
+
+type ctxMarker struct{}
+
+var (
+	// ctxMarkerKey is the Context value marker used by *all* logging middleware.
+	// The logging middleware object must interf
+	ctxMarkerKey = &ctxMarker{}
+	// NoopTags is a trivial, minimum overhead implementation of Tags for which all operations are no-ops.
+	NoopTags = &noopTags{}
+)
+
+// Tags is the interface used for storing request tags between Context calls.
+// The default implementation is *not* thread safe, and should be handled only in the context of the request.
+type Tags interface {
+	// Set sets the given key in the metadata tags.
+	Set(key string, value interface{}) Tags
+	// Has checks if the given key exists.
+	Has(key string) bool
+	// Values returns a map of key to values.
+	// Do not modify the underlying map, please use Set instead.
+	Values() map[string]interface{}
+}
+
+type mapTags struct {
+	values map[string]interface{}
+}
+
+func (t *mapTags) Set(key string, value interface{}) Tags {
+	t.values[key] = value
+	return t
+}
+
+func (t *mapTags) Has(key string) bool {
+	_, ok := t.values[key]
+	return ok
+}
+
+func (t *mapTags) Values() map[string]interface{} {
+	return t.values
+}
+
+type noopTags struct{}
+
+func (t *noopTags) Set(key string, value interface{}) Tags {
+	return t
+}
+
+func (t *noopTags) Has(key string) bool {
+	return false
+}
+
+func (t *noopTags) Values() map[string]interface{} {
+	return nil
+}
+
+// Extracts returns a pre-existing Tags object in the Context.
+// If the context wasn't set in a tag interceptor, a no-op Tag storage is returned that will *not* be propagated in context.
+func Extract(ctx context.Context) Tags {
+	t, ok := ctx.Value(ctxMarkerKey).(Tags)
+	if !ok {
+		return NoopTags
+	}
+
+	return t
+}
+
+func SetInContext(ctx context.Context, tags Tags) context.Context {
+	return context.WithValue(ctx, ctxMarkerKey, tags)
+}
+
+func NewTags() Tags {
+	return &mapTags{values: make(map[string]interface{})}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go
new file mode 100644
index 0000000..960638d
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/doc.go
@@ -0,0 +1,22 @@
+/*
+`grpc_ctxtags` adds a Tag object to the context that can be used by other middleware to add context about a request.
+
+Request Context Tags
+
+Tags describe information about the request, and can be set and used by other middleware, or handlers. Tags are used
+for logging and tracing of requests. Tags are populated both upwards, *and* downwards in the interceptor-handler stack.
+
+You can automatically extract tags (in `grpc.request.<field_name>`) from request payloads.
+
+For unary and server-streaming methods, pass in the `WithFieldExtractor` option. For client-streams and bidirectional-streams, you can
+use `WithFieldExtractorForInitialReq` which will extract the tags from the first message passed from client to server.
+Note the tags will not be modified for subsequent requests, so this option only makes sense when the initial message
+establishes the meta-data for the stream.
+
+If a user doesn't use the interceptors that initialize the `Tags` object, all operations following from an `Extract(ctx)`
+will be no-ops. This is to ensure that code doesn't panic if the interceptors weren't used.
+
+Tags fields are typed, and shallow and should follow the OpenTracing semantics convention:
+https://github.com/opentracing/specification/blob/master/semantic_conventions.md
+*/
+package grpc_ctxtags
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go
new file mode 100644
index 0000000..a4073ab
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/fieldextractor.go
@@ -0,0 +1,85 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+import (
+	"reflect"
+)
+
+// RequestFieldExtractorFunc is a user-provided function that extracts field information from a gRPC request.
+// It is called from tags middleware on arrival of unary request or a server-stream request.
+// Keys and values will be added to the context tags of the request. If there are no fields, you should return a nil.
+type RequestFieldExtractorFunc func(fullMethod string, req interface{}) map[string]interface{}
+
+type requestFieldsExtractor interface {
+	// ExtractRequestFields is a method declared on a Protobuf message that extracts fields from the interface.
+	// The values from the extracted fields should be set in the appendToMap, in order to avoid allocations.
+	ExtractRequestFields(appendToMap map[string]interface{})
+}
+
+// CodeGenRequestFieldExtractor is a function that relies on code-generated functions that export log fields from requests.
+// These are usually coming from a protoc-plugin that generates additional information based on custom field options.
+func CodeGenRequestFieldExtractor(fullMethod string, req interface{}) map[string]interface{} {
+	if ext, ok := req.(requestFieldsExtractor); ok {
+		retMap := make(map[string]interface{})
+		ext.ExtractRequestFields(retMap)
+		if len(retMap) == 0 {
+			return nil
+		}
+		return retMap
+	}
+	return nil
+}
+
+// TagBasedRequestFieldExtractor is a function that relies on Go struct tags to export log fields from requests.
+// These are usually coming from a protoc-plugin, such as Gogo protobuf.
+//
+//  message Metadata {
+//     repeated string tags = 1 [ (gogoproto.moretags) = "log_field:\"meta_tags\"" ];
+//  }
+//
+// The tagName is configurable using the tagName variable. Here it would be "log_field".
+func TagBasedRequestFieldExtractor(tagName string) RequestFieldExtractorFunc {
+	return func(fullMethod string, req interface{}) map[string]interface{} {
+		retMap := make(map[string]interface{})
+		reflectMessageTags(req, retMap, tagName)
+		if len(retMap) == 0 {
+			return nil
+		}
+		return retMap
+	}
+}
+
+func reflectMessageTags(msg interface{}, existingMap map[string]interface{}, tagName string) {
+	v := reflect.ValueOf(msg)
+	// Only deal with pointers to structs.
+	if v.Kind() != reflect.Ptr || v.Elem().Kind() != reflect.Struct {
+		return
+	}
+	// Deref the pointer get to the struct.
+	v = v.Elem()
+	t := v.Type()
+	for i := 0; i < v.NumField(); i++ {
+		field := v.Field(i)
+		kind := field.Kind()
+		// Only recurse down direct pointers, which should only be to nested structs.
+		if (kind == reflect.Ptr || kind == reflect.Interface) && field.CanInterface() {
+			reflectMessageTags(field.Interface(), existingMap, tagName)
+		}
+		// In case of arrays/slices (repeated fields) go down to the concrete type.
+		if kind == reflect.Array || kind == reflect.Slice {
+			if field.Len() == 0 {
+				continue
+			}
+			kind = field.Index(0).Kind()
+		}
+		// Only be interested in
+		if (kind >= reflect.Bool && kind <= reflect.Float64) || kind == reflect.String {
+			if tag := t.Field(i).Tag.Get(tagName); tag != "" {
+				existingMap[tag] = field.Interface()
+			}
+		}
+	}
+	return
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go
new file mode 100644
index 0000000..a7ced60
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/interceptors.go
@@ -0,0 +1,85 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/peer"
+
+	"github.com/grpc-ecosystem/go-grpc-middleware"
+)
+
+// UnaryServerInterceptor returns a new unary server interceptors that sets the values for request tags.
+func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor {
+	o := evaluateOptions(opts)
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		newCtx := newTagsForCtx(ctx)
+		if o.requestFieldsFunc != nil {
+			setRequestFieldTags(newCtx, o.requestFieldsFunc, info.FullMethod, req)
+		}
+		return handler(newCtx, req)
+	}
+}
+
+// StreamServerInterceptor returns a new streaming server interceptor that sets the values for request tags.
+func StreamServerInterceptor(opts ...Option) grpc.StreamServerInterceptor {
+	o := evaluateOptions(opts)
+	return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		newCtx := newTagsForCtx(stream.Context())
+		if o.requestFieldsFunc == nil {
+			// Short-circuit, don't do the expensive bit of allocating a wrappedStream.
+			wrappedStream := grpc_middleware.WrapServerStream(stream)
+			wrappedStream.WrappedContext = newCtx
+			return handler(srv, wrappedStream)
+		}
+		wrapped := &wrappedStream{stream, info, o, newCtx, true}
+		err := handler(srv, wrapped)
+		return err
+	}
+}
+
+// wrappedStream is a thin wrapper around grpc.ServerStream that allows modifying context and extracts log fields from the initial message.
+type wrappedStream struct {
+	grpc.ServerStream
+	info *grpc.StreamServerInfo
+	opts *options
+	// WrappedContext is the wrapper's own Context. You can assign it.
+	WrappedContext context.Context
+	initial        bool
+}
+
+// Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
+func (w *wrappedStream) Context() context.Context {
+	return w.WrappedContext
+}
+
+func (w *wrappedStream) RecvMsg(m interface{}) error {
+	err := w.ServerStream.RecvMsg(m)
+	// We only do log fields extraction on the single-request of a server-side stream.
+	if !w.info.IsClientStream || w.opts.requestFieldsFromInitial && w.initial {
+		w.initial = false
+
+		setRequestFieldTags(w.Context(), w.opts.requestFieldsFunc, w.info.FullMethod, m)
+	}
+	return err
+}
+
+func newTagsForCtx(ctx context.Context) context.Context {
+	t := NewTags()
+	if peer, ok := peer.FromContext(ctx); ok {
+		t.Set("peer.address", peer.Addr.String())
+	}
+	return SetInContext(ctx, t)
+}
+
+func setRequestFieldTags(ctx context.Context, f RequestFieldExtractorFunc, fullMethodName string, req interface{}) {
+	if valMap := f(fullMethodName, req); valMap != nil {
+		t := Extract(ctx)
+		for k, v := range valMap {
+			t.Set("grpc.request."+k, v)
+		}
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go
new file mode 100644
index 0000000..952775f
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tags/options.go
@@ -0,0 +1,44 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_ctxtags
+
+var (
+	defaultOptions = &options{
+		requestFieldsFunc: nil,
+	}
+)
+
+type options struct {
+	requestFieldsFunc        RequestFieldExtractorFunc
+	requestFieldsFromInitial bool
+}
+
+func evaluateOptions(opts []Option) *options {
+	optCopy := &options{}
+	*optCopy = *defaultOptions
+	for _, o := range opts {
+		o(optCopy)
+	}
+	return optCopy
+}
+
+type Option func(*options)
+
+// WithFieldExtractor customizes the function for extracting log fields from protobuf messages, for
+// unary and server-streamed methods only.
+func WithFieldExtractor(f RequestFieldExtractorFunc) Option {
+	return func(o *options) {
+		o.requestFieldsFunc = f
+	}
+}
+
+// WithFieldExtractorForInitialReq customizes the function for extracting log fields from protobuf messages,
+// for all unary and streaming methods. For client-streams and bidirectional-streams, the tags will be
+// extracted from the first message from the client.
+func WithFieldExtractorForInitialReq(f RequestFieldExtractorFunc) Option {
+	return func(o *options) {
+		o.requestFieldsFunc = f
+		o.requestFieldsFromInitial = true
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/client_interceptors.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/client_interceptors.go
new file mode 100644
index 0000000..2e9cafd
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/client_interceptors.go
@@ -0,0 +1,143 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_opentracing
+
+import (
+	"context"
+	"io"
+	"sync"
+
+	"github.com/grpc-ecosystem/go-grpc-middleware/util/metautils"
+	opentracing "github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/ext"
+	"github.com/opentracing/opentracing-go/log"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/metadata"
+)
+
+// UnaryClientInterceptor returns a new unary client interceptor for OpenTracing.
+func UnaryClientInterceptor(opts ...Option) grpc.UnaryClientInterceptor {
+	o := evaluateOptions(opts)
+	return func(parentCtx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		if o.filterOutFunc != nil && !o.filterOutFunc(parentCtx, method) {
+			return invoker(parentCtx, method, req, reply, cc, opts...)
+		}
+		newCtx, clientSpan := newClientSpanFromContext(parentCtx, o.tracer, method)
+		if o.unaryRequestHandlerFunc != nil {
+			o.unaryRequestHandlerFunc(clientSpan, req)
+		}
+		err := invoker(newCtx, method, req, reply, cc, opts...)
+		finishClientSpan(clientSpan, err)
+		return err
+	}
+}
+
+// StreamClientInterceptor returns a new streaming client interceptor for OpenTracing.
+func StreamClientInterceptor(opts ...Option) grpc.StreamClientInterceptor {
+	o := evaluateOptions(opts)
+	return func(parentCtx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		if o.filterOutFunc != nil && !o.filterOutFunc(parentCtx, method) {
+			return streamer(parentCtx, desc, cc, method, opts...)
+		}
+		newCtx, clientSpan := newClientSpanFromContext(parentCtx, o.tracer, method)
+		clientStream, err := streamer(newCtx, desc, cc, method, opts...)
+		if err != nil {
+			finishClientSpan(clientSpan, err)
+			return nil, err
+		}
+		return &tracedClientStream{ClientStream: clientStream, clientSpan: clientSpan}, nil
+	}
+}
+
+// type serverStreamingRetryingStream is the implementation of grpc.ClientStream that acts as a
+// proxy to the underlying call. If any of the RecvMsg() calls fail, it will try to reestablish
+// a new ClientStream according to the retry policy.
+type tracedClientStream struct {
+	grpc.ClientStream
+	mu              sync.Mutex
+	alreadyFinished bool
+	clientSpan      opentracing.Span
+}
+
+func (s *tracedClientStream) Header() (metadata.MD, error) {
+	h, err := s.ClientStream.Header()
+	if err != nil {
+		s.finishClientSpan(err)
+	}
+	return h, err
+}
+
+func (s *tracedClientStream) SendMsg(m interface{}) error {
+	err := s.ClientStream.SendMsg(m)
+	if err != nil {
+		s.finishClientSpan(err)
+	}
+	return err
+}
+
+func (s *tracedClientStream) CloseSend() error {
+	err := s.ClientStream.CloseSend()
+	s.finishClientSpan(err)
+	return err
+}
+
+func (s *tracedClientStream) RecvMsg(m interface{}) error {
+	err := s.ClientStream.RecvMsg(m)
+	if err != nil {
+		s.finishClientSpan(err)
+	}
+	return err
+}
+
+func (s *tracedClientStream) finishClientSpan(err error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.alreadyFinished {
+		finishClientSpan(s.clientSpan, err)
+		s.alreadyFinished = true
+	}
+}
+
+// ClientAddContextTags returns a context with specified opentracing tags, which
+// are used by UnaryClientInterceptor/StreamClientInterceptor when creating a
+// new span.
+func ClientAddContextTags(ctx context.Context, tags opentracing.Tags) context.Context {
+	return context.WithValue(ctx, clientSpanTagKey{}, tags)
+}
+
+type clientSpanTagKey struct{}
+
+func newClientSpanFromContext(ctx context.Context, tracer opentracing.Tracer, fullMethodName string) (context.Context, opentracing.Span) {
+	var parentSpanCtx opentracing.SpanContext
+	if parent := opentracing.SpanFromContext(ctx); parent != nil {
+		parentSpanCtx = parent.Context()
+	}
+	opts := []opentracing.StartSpanOption{
+		opentracing.ChildOf(parentSpanCtx),
+		ext.SpanKindRPCClient,
+		grpcTag,
+	}
+	if tagx := ctx.Value(clientSpanTagKey{}); tagx != nil {
+		if opt, ok := tagx.(opentracing.StartSpanOption); ok {
+			opts = append(opts, opt)
+		}
+	}
+	clientSpan := tracer.StartSpan(fullMethodName, opts...)
+	// Make sure we add this to the metadata of the call, so it gets propagated:
+	md := metautils.ExtractOutgoing(ctx).Clone()
+	if err := tracer.Inject(clientSpan.Context(), opentracing.HTTPHeaders, metadataTextMap(md)); err != nil {
+		grpclog.Infof("grpc_opentracing: failed serializing trace information: %v", err)
+	}
+	ctxWithMetadata := md.ToOutgoing(ctx)
+	return opentracing.ContextWithSpan(ctxWithMetadata, clientSpan), clientSpan
+}
+
+func finishClientSpan(clientSpan opentracing.Span, err error) {
+	if err != nil && err != io.EOF {
+		ext.Error.Set(clientSpan, true)
+		clientSpan.LogFields(log.String("event", "error"), log.String("message", err.Error()))
+	}
+	clientSpan.Finish()
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/doc.go
new file mode 100644
index 0000000..7a58efc
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/doc.go
@@ -0,0 +1,22 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+`grpc_opentracing` adds OpenTracing
+
+OpenTracing Interceptors
+
+These are both client-side and server-side interceptors for OpenTracing. They are a provider-agnostic, with backends
+such as Zipkin, or Google Stackdriver Trace.
+
+For a service that sends out requests and receives requests, you *need* to use both, otherwise downstream requests will
+not have the appropriate requests propagated.
+
+All server-side spans are tagged with grpc_ctxtags information.
+
+For more information see:
+http://opentracing.io/documentation/
+https://github.com/opentracing/specification/blob/master/semantic_conventions.md
+
+*/
+package grpc_opentracing
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/id_extract.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/id_extract.go
new file mode 100644
index 0000000..bc7302e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/id_extract.go
@@ -0,0 +1,82 @@
+package grpc_opentracing
+
+import (
+	"strings"
+
+	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
+	opentracing "github.com/opentracing/opentracing-go"
+	"google.golang.org/grpc/grpclog"
+)
+
+const (
+	TagTraceId           = "trace.traceid"
+	TagSpanId            = "trace.spanid"
+	TagSampled           = "trace.sampled"
+	jaegerNotSampledFlag = "0"
+)
+
+// injectOpentracingIdsToTags writes trace data to ctxtags.
+// This is done in an incredibly hacky way, because the public-facing interface of opentracing doesn't give access to
+// the TraceId and SpanId of the SpanContext. Only the Tracer's Inject/Extract methods know what these are.
+// Most tracers have them encoded as keys with 'traceid' and 'spanid':
+// https://github.com/openzipkin/zipkin-go-opentracing/blob/594640b9ef7e5c994e8d9499359d693c032d738c/propagation_ot.go#L29
+// https://github.com/opentracing/basictracer-go/blob/1b32af207119a14b1b231d451df3ed04a72efebf/propagation_ot.go#L26
+// Jaeger from Uber use one-key schema with next format '{trace-id}:{span-id}:{parent-span-id}:{flags}'
+// https://www.jaegertracing.io/docs/client-libraries/#trace-span-identity
+// Datadog uses keys ending with 'trace-id' and 'parent-id' (for span) by default:
+// https://github.com/DataDog/dd-trace-go/blob/v1/ddtrace/tracer/textmap.go#L77
+func injectOpentracingIdsToTags(traceHeaderName string, span opentracing.Span, tags grpc_ctxtags.Tags) {
+	if err := span.Tracer().Inject(span.Context(), opentracing.HTTPHeaders,
+		&tagsCarrier{Tags: tags, traceHeaderName: traceHeaderName}); err != nil {
+		grpclog.Infof("grpc_opentracing: failed extracting trace info into ctx %v", err)
+	}
+}
+
+// tagsCarrier is a really hacky way of
+type tagsCarrier struct {
+	grpc_ctxtags.Tags
+	traceHeaderName string
+}
+
+func (t *tagsCarrier) Set(key, val string) {
+	key = strings.ToLower(key)
+
+	if key == t.traceHeaderName {
+		parts := strings.Split(val, ":")
+		if len(parts) == 4 {
+			t.Tags.Set(TagTraceId, parts[0])
+			t.Tags.Set(TagSpanId, parts[1])
+
+			if parts[3] != jaegerNotSampledFlag {
+				t.Tags.Set(TagSampled, "true")
+			} else {
+				t.Tags.Set(TagSampled, "false")
+			}
+
+			return
+		}
+	}
+
+	if strings.Contains(key, "traceid") {
+		t.Tags.Set(TagTraceId, val) // this will most likely be base-16 (hex) encoded
+	}
+
+	if strings.Contains(key, "spanid") && !strings.Contains(strings.ToLower(key), "parent") {
+		t.Tags.Set(TagSpanId, val) // this will most likely be base-16 (hex) encoded
+	}
+
+	if strings.Contains(key, "sampled") {
+		switch val {
+		case "true", "false":
+			t.Tags.Set(TagSampled, val)
+		}
+	}
+
+	if strings.HasSuffix(key, "trace-id") {
+		t.Tags.Set(TagTraceId, val)
+	}
+
+	if strings.HasSuffix(key, "parent-id") {
+		t.Tags.Set(TagSpanId, val)
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/metadata.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/metadata.go
new file mode 100644
index 0000000..3649fb5
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/metadata.go
@@ -0,0 +1,50 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_opentracing
+
+import (
+	"encoding/base64"
+	"strings"
+
+	"google.golang.org/grpc/metadata"
+)
+
+const (
+	binHdrSuffix = "-bin"
+)
+
+// metadataTextMap extends a metadata.MD to be an opentracing textmap
+type metadataTextMap metadata.MD
+
+// Set is a opentracing.TextMapReader interface that extracts values.
+func (m metadataTextMap) Set(key, val string) {
+	// gRPC allows for complex binary values to be written.
+	encodedKey, encodedVal := encodeKeyValue(key, val)
+	// The metadata object is a multimap, and previous values may exist, but for opentracing headers, we do not append
+	// we just override.
+	m[encodedKey] = []string{encodedVal}
+}
+
+// ForeachKey is a opentracing.TextMapReader interface that extracts values.
+func (m metadataTextMap) ForeachKey(callback func(key, val string) error) error {
+	for k, vv := range m {
+		for _, v := range vv {
+			if err := callback(k, v); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// encodeKeyValue encodes key and value qualified for transmission via gRPC.
+// note: copy pasted from private values of grpc.metadata
+func encodeKeyValue(k, v string) (string, string) {
+	k = strings.ToLower(k)
+	if strings.HasSuffix(k, binHdrSuffix) {
+		val := base64.StdEncoding.EncodeToString([]byte(v))
+		v = string(val)
+	}
+	return k, v
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/options.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/options.go
new file mode 100644
index 0000000..430fe56
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/options.go
@@ -0,0 +1,89 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_opentracing
+
+import (
+	"context"
+
+	"github.com/opentracing/opentracing-go"
+)
+
+var (
+	defaultOptions = &options{
+		filterOutFunc: nil,
+		tracer:        nil,
+	}
+)
+
+// FilterFunc allows users to provide a function that filters out certain methods from being traced.
+//
+// If it returns false, the given request will not be traced.
+type FilterFunc func(ctx context.Context, fullMethodName string) bool
+
+// UnaryRequestHandlerFunc is a custom request handler
+type UnaryRequestHandlerFunc func(span opentracing.Span, req interface{})
+
+// OpNameFunc is a func that allows custom operation names instead of the gRPC method.
+type OpNameFunc func(method string) string
+
+type options struct {
+	filterOutFunc           FilterFunc
+	tracer                  opentracing.Tracer
+	traceHeaderName         string
+	unaryRequestHandlerFunc UnaryRequestHandlerFunc
+	opNameFunc              OpNameFunc
+}
+
+func evaluateOptions(opts []Option) *options {
+	optCopy := &options{}
+	*optCopy = *defaultOptions
+	for _, o := range opts {
+		o(optCopy)
+	}
+	if optCopy.tracer == nil {
+		optCopy.tracer = opentracing.GlobalTracer()
+	}
+	if optCopy.traceHeaderName == "" {
+		optCopy.traceHeaderName = "uber-trace-id"
+	}
+	return optCopy
+}
+
+type Option func(*options)
+
+// WithFilterFunc customizes the function used for deciding whether a given call is traced or not.
+func WithFilterFunc(f FilterFunc) Option {
+	return func(o *options) {
+		o.filterOutFunc = f
+	}
+}
+
+// WithTraceHeaderName customizes the trace header name where trace metadata passed with requests.
+// Default one is `uber-trace-id`
+func WithTraceHeaderName(name string) Option {
+	return func(o *options) {
+		o.traceHeaderName = name
+	}
+}
+
+// WithTracer sets a custom tracer to be used for this middleware, otherwise the opentracing.GlobalTracer is used.
+func WithTracer(tracer opentracing.Tracer) Option {
+	return func(o *options) {
+		o.tracer = tracer
+	}
+}
+
+// WithUnaryRequestHandlerFunc sets a custom handler for the request
+func WithUnaryRequestHandlerFunc(f UnaryRequestHandlerFunc) Option {
+	return func(o *options) {
+		o.unaryRequestHandlerFunc = f
+	}
+}
+
+// WithOpName customizes the trace Operation name
+func WithOpName(f OpNameFunc) Option {
+	return func(o *options) {
+		o.opNameFunc = f
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/server_interceptors.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/server_interceptors.go
new file mode 100644
index 0000000..186b108
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing/server_interceptors.go
@@ -0,0 +1,98 @@
+// Copyright 2017 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_opentracing
+
+import (
+	"context"
+
+	"github.com/grpc-ecosystem/go-grpc-middleware"
+	"github.com/grpc-ecosystem/go-grpc-middleware/tags"
+	"github.com/grpc-ecosystem/go-grpc-middleware/util/metautils"
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/ext"
+	"github.com/opentracing/opentracing-go/log"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/grpclog"
+)
+
+var (
+	grpcTag = opentracing.Tag{Key: string(ext.Component), Value: "gRPC"}
+)
+
+// UnaryServerInterceptor returns a new unary server interceptor for OpenTracing.
+func UnaryServerInterceptor(opts ...Option) grpc.UnaryServerInterceptor {
+	o := evaluateOptions(opts)
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		if o.filterOutFunc != nil && !o.filterOutFunc(ctx, info.FullMethod) {
+			return handler(ctx, req)
+		}
+		opName := info.FullMethod
+		if o.opNameFunc != nil {
+			opName = o.opNameFunc(info.FullMethod)
+		}
+		newCtx, serverSpan := newServerSpanFromInbound(ctx, o.tracer, o.traceHeaderName, opName)
+		if o.unaryRequestHandlerFunc != nil {
+			o.unaryRequestHandlerFunc(serverSpan, req)
+		}
+		resp, err := handler(newCtx, req)
+		finishServerSpan(ctx, serverSpan, err)
+		return resp, err
+	}
+}
+
+// StreamServerInterceptor returns a new streaming server interceptor for OpenTracing.
+func StreamServerInterceptor(opts ...Option) grpc.StreamServerInterceptor {
+	o := evaluateOptions(opts)
+	return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if o.filterOutFunc != nil && !o.filterOutFunc(stream.Context(), info.FullMethod) {
+			return handler(srv, stream)
+		}
+		opName := info.FullMethod
+		if o.opNameFunc != nil {
+			opName = o.opNameFunc(info.FullMethod)
+		}
+		newCtx, serverSpan := newServerSpanFromInbound(stream.Context(), o.tracer, o.traceHeaderName, opName)
+		wrappedStream := grpc_middleware.WrapServerStream(stream)
+		wrappedStream.WrappedContext = newCtx
+		err := handler(srv, wrappedStream)
+		finishServerSpan(newCtx, serverSpan, err)
+		return err
+	}
+}
+
+func newServerSpanFromInbound(ctx context.Context, tracer opentracing.Tracer, traceHeaderName, opName string) (context.Context, opentracing.Span) {
+	md := metautils.ExtractIncoming(ctx)
+	parentSpanContext, err := tracer.Extract(opentracing.HTTPHeaders, metadataTextMap(md))
+	if err != nil && err != opentracing.ErrSpanContextNotFound {
+		grpclog.Infof("grpc_opentracing: failed parsing trace information: %v", err)
+	}
+
+	serverSpan := tracer.StartSpan(
+		opName,
+		// this is magical, it attaches the new span to the parent parentSpanContext, and creates an unparented one if empty.
+		ext.RPCServerOption(parentSpanContext),
+		grpcTag,
+	)
+
+	injectOpentracingIdsToTags(traceHeaderName, serverSpan, grpc_ctxtags.Extract(ctx))
+	return opentracing.ContextWithSpan(ctx, serverSpan), serverSpan
+}
+
+func finishServerSpan(ctx context.Context, serverSpan opentracing.Span, err error) {
+	// Log context information
+	tags := grpc_ctxtags.Extract(ctx)
+	for k, v := range tags.Values() {
+		// Don't tag errors, log them instead.
+		if vErr, ok := v.(error); ok {
+			serverSpan.LogKV(k, vErr.Error())
+		} else {
+			serverSpan.SetTag(k, v)
+		}
+	}
+	if err != nil {
+		ext.Error.Set(serverSpan, true)
+		serverSpan.LogFields(log.String("event", "error"), log.String("message", err.Error()))
+	}
+	serverSpan.Finish()
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/doc.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/doc.go
new file mode 100644
index 0000000..1ed9bb4
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/doc.go
@@ -0,0 +1,19 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+/*
+Package `metautils` provides convenience functions for dealing with gRPC metadata.MD objects inside
+Context handlers.
+
+While the upstream grpc-go package contains decent functionality (see https://github.com/grpc/grpc-go/blob/master/Documentation/grpc-metadata.md)
+they are hard to use.
+
+The majority of functions center around the NiceMD, which is a convenience wrapper around metadata.MD. For example
+the following code allows you to easily extract incoming metadata (server handler) and put it into a new client context
+metadata.
+
+  nmd := metautils.ExtractIncoming(serverCtx).Clone(":authorization", ":custom")
+  clientCtx := nmd.Set("x-client-header", "2").Set("x-another", "3").ToOutgoing(ctx)
+*/
+
+package metautils
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go
new file mode 100644
index 0000000..1c60585
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go
@@ -0,0 +1,126 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package metautils
+
+import (
+	"context"
+	"strings"
+
+	"google.golang.org/grpc/metadata"
+)
+
+// NiceMD is a convenience wrapper definiting extra functions on the metadata.
+type NiceMD metadata.MD
+
+// ExtractIncoming extracts an inbound metadata from the server-side context.
+//
+// This function always returns a NiceMD wrapper of the metadata.MD, in case the context doesn't have metadata it returns
+// a new empty NiceMD.
+func ExtractIncoming(ctx context.Context) NiceMD {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return NiceMD(metadata.Pairs())
+	}
+	return NiceMD(md)
+}
+
+// ExtractOutgoing extracts an outbound metadata from the client-side context.
+//
+// This function always returns a NiceMD wrapper of the metadata.MD, in case the context doesn't have metadata it returns
+// a new empty NiceMD.
+func ExtractOutgoing(ctx context.Context) NiceMD {
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		return NiceMD(metadata.Pairs())
+	}
+	return NiceMD(md)
+}
+
+// Clone performs a *deep* copy of the metadata.MD.
+//
+// You can specify the lower-case copiedKeys to only copy certain whitelisted keys. If no keys are explicitly whitelisted
+// all keys get copied.
+func (m NiceMD) Clone(copiedKeys ...string) NiceMD {
+	newMd := NiceMD(metadata.Pairs())
+	for k, vv := range m {
+		found := false
+		if len(copiedKeys) == 0 {
+			found = true
+		} else {
+			for _, allowedKey := range copiedKeys {
+				if strings.EqualFold(allowedKey, k) {
+					found = true
+					break
+				}
+			}
+		}
+		if !found {
+			continue
+		}
+		newMd[k] = make([]string, len(vv))
+		copy(newMd[k], vv)
+	}
+	return NiceMD(newMd)
+}
+
+// ToOutgoing sets the given NiceMD as a client-side context for dispatching.
+func (m NiceMD) ToOutgoing(ctx context.Context) context.Context {
+	return metadata.NewOutgoingContext(ctx, metadata.MD(m))
+}
+
+// ToIncoming sets the given NiceMD as a server-side context for dispatching.
+//
+// This is mostly useful in ServerInterceptors..
+func (m NiceMD) ToIncoming(ctx context.Context) context.Context {
+	return metadata.NewIncomingContext(ctx, metadata.MD(m))
+}
+
+// Get retrieves a single value from the metadata.
+//
+// It works analogously to http.Header.Get, returning the first value if there are many set. If the value is not set,
+// an empty string is returned.
+//
+// The function is binary-key safe.
+func (m NiceMD) Get(key string) string {
+	k := strings.ToLower(key)
+	vv, ok := m[k]
+	if !ok {
+		return ""
+	}
+	return vv[0]
+}
+
+// Del retrieves a single value from the metadata.
+//
+// It works analogously to http.Header.Del, deleting all values if they exist.
+//
+// The function is binary-key safe.
+
+func (m NiceMD) Del(key string) NiceMD {
+	k := strings.ToLower(key)
+	delete(m, k)
+	return m
+}
+
+// Set sets the given value in a metadata.
+//
+// It works analogously to http.Header.Set, overwriting all previous metadata values.
+//
+// The function is binary-key safe.
+func (m NiceMD) Set(key string, value string) NiceMD {
+	k := strings.ToLower(key)
+	m[k] = []string{value}
+	return m
+}
+
+// Add retrieves a single value from the metadata.
+//
+// It works analogously to http.Header.Add, as it appends to any existing values associated with key.
+//
+// The function is binary-key safe.
+func (m NiceMD) Add(key string, value string) NiceMD {
+	k := strings.ToLower(key)
+	m[k] = append(m[k], value)
+	return m
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
new file mode 100644
index 0000000..05ccfb3
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
@@ -0,0 +1,30 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_middleware
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+)
+
+// WrappedServerStream is a thin wrapper around grpc.ServerStream that allows modifying context.
+type WrappedServerStream struct {
+	grpc.ServerStream
+	// WrappedContext is the wrapper's own Context. You can assign it.
+	WrappedContext context.Context
+}
+
+// Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
+func (w *WrappedServerStream) Context() context.Context {
+	return w.WrappedContext
+}
+
+// WrapServerStream returns a ServerStream that has the ability to overwrite context.
+func WrapServerStream(stream grpc.ServerStream) *WrappedServerStream {
+	if existing, ok := stream.(*WrappedServerStream); ok {
+		return existing
+	}
+	return &WrappedServerStream{ServerStream: stream, WrappedContext: stream.Context()}
+}