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..c198e6a
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.gitignore
@@ -0,0 +1,202 @@
+# 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/
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..702fa5b
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/.travis.yml
@@ -0,0 +1,21 @@
+sudo: false
+language: go
+go:
+  - 1.8.x
+env:
+  - DEP_VERSION="0.3.2"
+
+before_install:
+  # Download the binary to bin folder in $GOPATH
+  - curl -L -s https://github.com/golang/dep/releases/download/v${DEP_VERSION}/dep-linux-amd64 -o $GOPATH/bin/dep
+  # Make the binary executable
+  - chmod +x $GOPATH/bin/dep
+
+install:
+  - dep ensure
+
+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..0e64822
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/CHANGELOG.md
@@ -0,0 +1,30 @@
+# 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
+- This CHANGELOG file to keep track of changes.
+
+## 1.0.0 - 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/v1.0.0...HEAD 
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/Gopkg.lock b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/Gopkg.lock
new file mode 100644
index 0000000..ebdcb75
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/Gopkg.lock
@@ -0,0 +1,123 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  name = "cloud.google.com/go"
+  packages = ["compute/metadata"]
+  revision = "2d3a6656c17a60b0815b7e06ab0be04eacb6e613"
+  version = "v0.16.0"
+
+[[projects]]
+  name = "github.com/davecgh/go-spew"
+  packages = ["spew"]
+  revision = "346938d642f2ec3594ed81d874461961cd0faa76"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "github.com/gogo/protobuf"
+  packages = ["gogoproto","proto","protoc-gen-gogo/descriptor"]
+  revision = "342cbe0a04158f6dcb03ca0079991a51a4248c02"
+  version = "v0.5"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/golang/protobuf"
+  packages = ["jsonpb","proto","ptypes","ptypes/any","ptypes/duration","ptypes/struct","ptypes/timestamp"]
+  revision = "1e59b77b52bf8e4b449a57e6f79f21226d571845"
+
+[[projects]]
+  name = "github.com/opentracing/opentracing-go"
+  packages = [".","ext","log","mocktracer"]
+  revision = "1949ddbfd147afd4d964a9f00b24eb291e0e7c38"
+  version = "v1.0.2"
+
+[[projects]]
+  name = "github.com/pmezard/go-difflib"
+  packages = ["difflib"]
+  revision = "792786c7400a136282c1664665ae0a8db921c6c2"
+  version = "v1.0.0"
+
+[[projects]]
+  name = "github.com/sirupsen/logrus"
+  packages = ["."]
+  revision = "f006c2ac4710855cf0f916dd6b77acf6b048dc6e"
+  version = "v1.0.3"
+
+[[projects]]
+  name = "github.com/stretchr/testify"
+  packages = ["assert","require","suite"]
+  revision = "69483b4bd14f5845b5a1e55bca19e954e827f1d0"
+  version = "v1.1.4"
+
+[[projects]]
+  name = "go.uber.org/atomic"
+  packages = ["."]
+  revision = "8474b86a5a6f79c443ce4b2992817ff32cf208b8"
+  version = "v1.3.1"
+
+[[projects]]
+  name = "go.uber.org/multierr"
+  packages = ["."]
+  revision = "3c4937480c32f4c13a875a1829af76c98ca3d40a"
+  version = "v1.1.0"
+
+[[projects]]
+  name = "go.uber.org/zap"
+  packages = [".","buffer","internal/bufferpool","internal/color","internal/exit","zapcore"]
+  revision = "35aad584952c3e7020db7b839f6b102de6271f89"
+  version = "v1.7.1"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/crypto"
+  packages = ["ssh/terminal"]
+  revision = "94eea52f7b742c7cbe0b03b22f0c4c8631ece122"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/net"
+  packages = ["context","context/ctxhttp","http2","http2/hpack","idna","internal/timeseries","lex/httplex","trace"]
+  revision = "a8b9294777976932365dabb6640cf1468d95c70f"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/oauth2"
+  packages = [".","google","internal","jws","jwt"]
+  revision = "f95fa95eaa936d9d87489b15d1d18b97c1ba9c28"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/sys"
+  packages = ["unix","windows"]
+  revision = "13fcbd661c8ececa8807a29b48407d674b1d8ed8"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/text"
+  packages = ["collate","collate/build","internal/colltab","internal/gen","internal/tag","internal/triegen","internal/ucd","language","secure/bidirule","transform","unicode/bidi","unicode/cldr","unicode/norm","unicode/rangetable"]
+  revision = "75cc3cad82b5f47d3fb229ddda8c5167da14f294"
+
+[[projects]]
+  name = "google.golang.org/appengine"
+  packages = [".","internal","internal/app_identity","internal/base","internal/datastore","internal/log","internal/modules","internal/remote_api","internal/urlfetch","urlfetch"]
+  revision = "150dc57a1b433e64154302bdc40b6bb8aefa313a"
+  version = "v1.0.0"
+
+[[projects]]
+  branch = "master"
+  name = "google.golang.org/genproto"
+  packages = ["googleapis/rpc/status"]
+  revision = "7f0da29060c682909f650ad8ed4e515bd74fa12a"
+
+[[projects]]
+  name = "google.golang.org/grpc"
+  packages = [".","balancer","balancer/roundrobin","codes","connectivity","credentials","credentials/oauth","encoding","grpclb/grpc_lb_v1/messages","grpclog","internal","keepalive","metadata","naming","peer","resolver","resolver/dns","resolver/passthrough","stats","status","tap","transport"]
+  revision = "5a9f7b402fe85096d2e1d0383435ee1876e863d0"
+  version = "v1.8.0"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "b24c6670412eb0bc44ed1db77fecc52333f8725f3e3272bdc568f5683a63031f"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/Gopkg.toml b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/Gopkg.toml
new file mode 100644
index 0000000..0a7d4c1
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/Gopkg.toml
@@ -0,0 +1,35 @@
+[[constraint]]
+  name = "github.com/gogo/protobuf"
+  version = "0.5.0"
+
+[[constraint]]
+  branch = "master"
+  name = "github.com/golang/protobuf"
+
+[[constraint]]
+  name = "github.com/opentracing/opentracing-go"
+  version = "1.0.2"
+
+[[constraint]]
+  name = "github.com/sirupsen/logrus"
+  version = "1.0.3"
+
+[[constraint]]
+  name = "github.com/stretchr/testify"
+  version = "1.1.4"
+
+[[constraint]]
+  name = "go.uber.org/zap"
+  version = "1.7.1"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/net"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/oauth2"
+
+[[constraint]]
+  name = "google.golang.org/grpc"
+  version = "1.8.0"
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
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   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 "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
\ 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..224069b
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/README.md
@@ -0,0 +1,84 @@
+# 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](slack.png)](https://join.slack.com/t/improbable-eng/shared_invite/enQtMzQ1ODcyMzQ5MjM4LWY5ZWZmNGM2ODc5MmViNmQ3ZTA3ZTY3NzQwOTBlMTkzZmIxZTIxODk0OWU3YjZhNWVlNDU3MDlkZGViZjhkMjc)
+
+[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 either 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_ctxtags.StreamServerInterceptor(),
+        grpc_opentracing.StreamServerInterceptor(),
+        grpc_prometheus.StreamServerInterceptor,
+        grpc_zap.StreamServerInterceptor(zapLogger),
+        grpc_auth.StreamServerInterceptor(myAuthFunction),
+        grpc_recovery.StreamServerInterceptor(),
+    )),
+    grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
+        grpc_ctxtags.UnaryServerInterceptor(),
+        grpc_opentracing.UnaryServerInterceptor(),
+        grpc_prometheus.UnaryServerInterceptor,
+        grpc_zap.UnaryServerInterceptor(zapLogger),
+        grpc_auth.UnaryServerInterceptor(myAuthFunction),
+        grpc_recovery.UnaryServerInterceptor(),
+    )),
+)
+```
+
+## 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.
+
+
+#### 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
+
+
+## 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..45a2f5f
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain.go
@@ -0,0 +1,183 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+// gRPC Server Interceptor chaining middleware.
+
+package grpc_middleware
+
+import (
+	"golang.org/x/net/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)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+			var (
+				chainHandler grpc.UnaryHandler
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentReq interface{}) (interface{}, error) {
+				if curI == lastI {
+					return handler(currentCtx, currentReq)
+				}
+				curI++
+				resp, err := interceptors[curI](currentCtx, currentReq, info, chainHandler)
+				curI--
+				return resp, err
+			}
+
+			return interceptors[0](ctx, req, info, chainHandler)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, req interface{}, _ *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		return handler(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)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+			var (
+				chainHandler grpc.StreamHandler
+				curI         int
+			)
+
+			chainHandler = func(currentSrv interface{}, currentStream grpc.ServerStream) error {
+				if curI == lastI {
+					return handler(currentSrv, currentStream)
+				}
+				curI++
+				err := interceptors[curI](currentSrv, currentStream, info, chainHandler)
+				curI--
+				return err
+			}
+
+			return interceptors[0](srv, stream, info, chainHandler)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(srv interface{}, stream grpc.ServerStream, _ *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		return handler(srv, stream)
+	}
+}
+
+// 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)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+			var (
+				chainHandler grpc.UnaryInvoker
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentMethod string, currentReq, currentRepl interface{}, currentConn *grpc.ClientConn, currentOpts ...grpc.CallOption) error {
+				if curI == lastI {
+					return invoker(currentCtx, currentMethod, currentReq, currentRepl, currentConn, currentOpts...)
+				}
+				curI++
+				err := interceptors[curI](currentCtx, currentMethod, currentReq, currentRepl, currentConn, chainHandler, currentOpts...)
+				curI--
+				return err
+			}
+
+			return interceptors[0](ctx, method, req, reply, cc, chainHandler, opts...)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		return invoker(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)
+
+	if n > 1 {
+		lastI := n - 1
+		return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+			var (
+				chainHandler grpc.Streamer
+				curI         int
+			)
+
+			chainHandler = func(currentCtx context.Context, currentDesc *grpc.StreamDesc, currentConn *grpc.ClientConn, currentMethod string, currentOpts ...grpc.CallOption) (grpc.ClientStream, error) {
+				if curI == lastI {
+					return streamer(currentCtx, currentDesc, currentConn, currentMethod, currentOpts...)
+				}
+				curI++
+				stream, err := interceptors[curI](currentCtx, currentDesc, currentConn, currentMethod, chainHandler, currentOpts...)
+				curI--
+				return stream, err
+			}
+
+			return interceptors[0](ctx, desc, cc, method, chainHandler, opts...)
+		}
+	}
+
+	if n == 1 {
+		return interceptors[0]
+	}
+
+	// n == 0; Dummy interceptor maintained for backward compatibility to avoid returning nil.
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		return streamer(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..7168950
--- /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, stream)
+	}
+*/
+package grpc_middleware
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..51dc5b8
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/makefile
@@ -0,0 +1,16 @@
+SHELL=/bin/bash
+
+GOFILES_NOVENDOR = $(shell go list ./... | grep -v /vendor/)
+
+all: vet fmt test
+
+fmt:
+	go fmt $(GOFILES_NOVENDOR)
+
+vet:
+	go vet $(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/wrappers.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
new file mode 100644
index 0000000..597b862
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
@@ -0,0 +1,29 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_middleware
+
+import (
+	"golang.org/x/net/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()}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.gitignore b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.gitignore
new file mode 100644
index 0000000..2233cff
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.gitignore
@@ -0,0 +1,201 @@
+#vendor
+vendor/
+
+# Created by .ignore support plugin (hsz.mobi)
+coverage.txt
+### 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/
+
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.travis.yml b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.travis.yml
new file mode 100644
index 0000000..2a845b9
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/.travis.yml
@@ -0,0 +1,25 @@
+sudo: false
+language: go
+# * github.com/grpc/grpc-go still supports go1.6
+#   - When we drop support for go1.6 we can remove golang.org/x/net/context
+#     below as it is part of the Go std library since go1.7
+# * github.com/prometheus/client_golang already requires at least go1.7 since
+#   September 2017
+go:
+  - 1.6.x
+  - 1.7.x
+  - 1.8.x
+  - 1.9.x
+  - 1.10.x
+  - master
+
+install:
+  - go get github.com/prometheus/client_golang/prometheus
+  - go get google.golang.org/grpc
+  - go get golang.org/x/net/context
+  - go get github.com/stretchr/testify
+script:
+ - make test 
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/CHANGELOG.md b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/CHANGELOG.md
new file mode 100644
index 0000000..19a8059
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/CHANGELOG.md
@@ -0,0 +1,24 @@
+# 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).
+
+## [Unreleased]
+
+## [1.2.0](https://github.com/grpc-ecosystem/go-grpc-prometheus/releases/tag/v1.2.0) - 2018-06-04
+
+### Added
+
+* Provide metrics object as `prometheus.Collector`, for conventional metric registration.
+* Support non-default/global Prometheus registry.
+* Allow configuring counters with `prometheus.CounterOpts`.
+
+### Changed
+
+* Remove usage of deprecated `grpc.Code()`.
+* Remove usage of deprecated `grpc.Errorf` and replace with `status.Errorf`.
+
+---
+
+This changelog was started with version `v1.2.0`, for earlier versions refer to the respective [GitHub releases](https://github.com/grpc-ecosystem/go-grpc-prometheus/releases).
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/LICENSE b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/LICENSE
new file mode 100644
index 0000000..b2b0650
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/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
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   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 "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
\ No newline at end of file
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/README.md b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/README.md
new file mode 100644
index 0000000..499c583
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/README.md
@@ -0,0 +1,247 @@
+# Go gRPC Interceptors for Prometheus monitoring 
+
+[![Travis Build](https://travis-ci.org/grpc-ecosystem/go-grpc-prometheus.svg)](https://travis-ci.org/grpc-ecosystem/go-grpc-prometheus)
+[![Go Report Card](https://goreportcard.com/badge/github.com/grpc-ecosystem/go-grpc-prometheus)](http://goreportcard.com/report/grpc-ecosystem/go-grpc-prometheus)
+[![GoDoc](http://img.shields.io/badge/GoDoc-Reference-blue.svg)](https://godoc.org/github.com/grpc-ecosystem/go-grpc-prometheus)
+[![SourceGraph](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-prometheus/-/badge.svg)](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-prometheus/?badge)
+[![codecov](https://codecov.io/gh/grpc-ecosystem/go-grpc-prometheus/branch/master/graph/badge.svg)](https://codecov.io/gh/grpc-ecosystem/go-grpc-prometheus)
+[![Apache 2.0 License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE)
+
+[Prometheus](https://prometheus.io/) monitoring for your [gRPC Go](https://github.com/grpc/grpc-go) servers and clients.
+
+A sister implementation for [gRPC Java](https://github.com/grpc/grpc-java) (same metrics, same semantics) is in [grpc-ecosystem/java-grpc-prometheus](https://github.com/grpc-ecosystem/java-grpc-prometheus).
+
+## Interceptors
+
+[gRPC Go](https://github.com/grpc/grpc-go) recently acquired support for Interceptors, i.e. middleware that is executed
+by a gRPC Server before the request is passed onto the user's application logic. It is a perfect way to implement
+common patterns: auth, logging and... monitoring.
+
+To use Interceptors in chains, please see [`go-grpc-middleware`](https://github.com/mwitkow/go-grpc-middleware).
+
+## Usage
+
+There are two types of interceptors: client-side and server-side. This package provides monitoring Interceptors for both.
+
+### Server-side
+
+```go
+import "github.com/grpc-ecosystem/go-grpc-prometheus"
+...
+    // Initialize your gRPC server's interceptor.
+    myServer := grpc.NewServer(
+        grpc.StreamInterceptor(grpc_prometheus.StreamServerInterceptor),
+        grpc.UnaryInterceptor(grpc_prometheus.UnaryServerInterceptor),
+    )
+    // Register your gRPC service implementations.
+    myservice.RegisterMyServiceServer(s.server, &myServiceImpl{})
+    // After all your registrations, make sure all of the Prometheus metrics are initialized.
+    grpc_prometheus.Register(myServer)
+    // Register Prometheus metrics handler.    
+    http.Handle("/metrics", promhttp.Handler())
+...
+```
+
+### Client-side
+
+```go
+import "github.com/grpc-ecosystem/go-grpc-prometheus"
+...
+   clientConn, err = grpc.Dial(
+       address,
+		   grpc.WithUnaryInterceptor(grpc_prometheus.UnaryClientInterceptor),
+		   grpc.WithStreamInterceptor(grpc_prometheus.StreamClientInterceptor)
+   )
+   client = pb_testproto.NewTestServiceClient(clientConn)
+   resp, err := client.PingEmpty(s.ctx, &myservice.Request{Msg: "hello"})
+...
+```
+
+# Metrics
+
+## Labels
+
+All server-side metrics start with `grpc_server` as Prometheus subsystem name. All client-side metrics start with `grpc_client`. Both of them have mirror-concepts. Similarly all methods
+contain the same rich labels:
+  
+  * `grpc_service` - the [gRPC service](http://www.grpc.io/docs/#defining-a-service) name, which is the combination of protobuf `package` and
+    the `grpc_service` section name. E.g. for `package = mwitkow.testproto` and 
+     `service TestService` the label will be `grpc_service="mwitkow.testproto.TestService"`
+  * `grpc_method` - the name of the method called on the gRPC service. E.g.  
+    `grpc_method="Ping"`
+  * `grpc_type` - the gRPC [type of request](http://www.grpc.io/docs/guides/concepts.html#rpc-life-cycle). 
+    Differentiating between the two is important especially for latency measurements.
+
+     - `unary` is single request, single response RPC
+     - `client_stream` is a multi-request, single response RPC
+     - `server_stream` is a single request, multi-response RPC
+     - `bidi_stream` is a multi-request, multi-response RPC
+    
+
+Additionally for completed RPCs, the following labels are used:
+
+  * `grpc_code` - the human-readable [gRPC status code](https://github.com/grpc/grpc-go/blob/master/codes/codes.go).
+    The list of all statuses is to long, but here are some common ones:
+      
+      - `OK` - means the RPC was successful
+      - `IllegalArgument` - RPC contained bad values
+      - `Internal` - server-side error not disclosed to the clients
+      
+## Counters
+
+The counters and their up to date documentation is in [server_reporter.go](server_reporter.go) and [client_reporter.go](client_reporter.go) 
+the respective Prometheus handler (usually `/metrics`). 
+
+For the purpose of this documentation we will only discuss `grpc_server` metrics. The `grpc_client` ones contain mirror concepts.
+
+For simplicity, let's assume we're tracking a single server-side RPC call of [`mwitkow.testproto.TestService`](examples/testproto/test.proto),
+calling the method `PingList`. The call succeeds and returns 20 messages in the stream.
+
+First, immediately after the server receives the call it will increment the
+`grpc_server_started_total` and start the handling time clock (if histograms are enabled). 
+
+```jsoniq
+grpc_server_started_total{grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 1
+```
+
+Then the user logic gets invoked. It receives one message from the client containing the request 
+(it's a `server_stream`):
+
+```jsoniq
+grpc_server_msg_received_total{grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 1
+```
+
+The user logic may return an error, or send multiple messages back to the client. In this case, on 
+each of the 20 messages sent back, a counter will be incremented:
+
+```jsoniq
+grpc_server_msg_sent_total{grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 20
+```
+
+After the call completes, its status (`OK` or other [gRPC status code](https://github.com/grpc/grpc-go/blob/master/codes/codes.go)) 
+and the relevant call labels increment the `grpc_server_handled_total` counter.
+
+```jsoniq
+grpc_server_handled_total{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 1
+```
+
+## Histograms
+
+[Prometheus histograms](https://prometheus.io/docs/concepts/metric_types/#histogram) are a great way
+to measure latency distributions of your RPCs. However, since it is bad practice to have metrics
+of [high cardinality](https://prometheus.io/docs/practices/instrumentation/#do-not-overuse-labels)
+the latency monitoring metrics are disabled by default. To enable them please call the following
+in your server initialization code:
+
+```jsoniq
+grpc_prometheus.EnableHandlingTimeHistogram()
+```
+
+After the call completes, its handling time will be recorded in a [Prometheus histogram](https://prometheus.io/docs/concepts/metric_types/#histogram)
+variable `grpc_server_handling_seconds`. The histogram variable contains three sub-metrics:
+
+ * `grpc_server_handling_seconds_count` - the count of all completed RPCs by status and method 
+ * `grpc_server_handling_seconds_sum` - cumulative time of RPCs by status and method, useful for 
+   calculating average handling times
+ * `grpc_server_handling_seconds_bucket` - contains the counts of RPCs by status and method in respective
+   handling-time buckets. These buckets can be used by Prometheus to estimate SLAs (see [here](https://prometheus.io/docs/practices/histograms/))
+
+The counter values will look as follows:
+
+```jsoniq
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.005"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.01"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.025"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.05"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.1"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.25"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="0.5"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="1"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="2.5"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="5"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="10"} 1
+grpc_server_handling_seconds_bucket{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream",le="+Inf"} 1
+grpc_server_handling_seconds_sum{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 0.0003866430000000001
+grpc_server_handling_seconds_count{grpc_code="OK",grpc_method="PingList",grpc_service="mwitkow.testproto.TestService",grpc_type="server_stream"} 1
+```
+
+
+## Useful query examples
+
+Prometheus philosophy is to provide raw metrics to the monitoring system, and
+let the aggregations be handled there. The verbosity of above metrics make it possible to have that
+flexibility. Here's a couple of useful monitoring queries:
+
+
+### request inbound rate
+```jsoniq
+sum(rate(grpc_server_started_total{job="foo"}[1m])) by (grpc_service)
+```
+For `job="foo"` (common label to differentiate between Prometheus monitoring targets), calculate the
+rate of requests per second (1 minute window) for each gRPC `grpc_service` that the job has. Please note
+how the `grpc_method` is being omitted here: all methods of a given gRPC service will be summed together.
+
+### unary request error rate
+```jsoniq
+sum(rate(grpc_server_handled_total{job="foo",grpc_type="unary",grpc_code!="OK"}[1m])) by (grpc_service)
+```
+For `job="foo"`, calculate the per-`grpc_service` rate of `unary` (1:1) RPCs that failed, i.e. the 
+ones that didn't finish with `OK` code.
+
+### unary request error percentage
+```jsoniq
+sum(rate(grpc_server_handled_total{job="foo",grpc_type="unary",grpc_code!="OK"}[1m])) by (grpc_service)
+ / 
+sum(rate(grpc_server_started_total{job="foo",grpc_type="unary"}[1m])) by (grpc_service)
+ * 100.0
+```
+For `job="foo"`, calculate the percentage of failed requests by service. It's easy to notice that
+this is a combination of the two above examples. This is an example of a query you would like to
+[alert on](https://prometheus.io/docs/alerting/rules/) in your system for SLA violations, e.g.
+"no more than 1% requests should fail".
+
+### average response stream size
+```jsoniq
+sum(rate(grpc_server_msg_sent_total{job="foo",grpc_type="server_stream"}[10m])) by (grpc_service)
+ /
+sum(rate(grpc_server_started_total{job="foo",grpc_type="server_stream"}[10m])) by (grpc_service)
+```
+For `job="foo"` what is the `grpc_service`-wide `10m` average of messages returned for all `
+server_stream` RPCs. This allows you to track the stream sizes returned by your system, e.g. allows 
+you to track when clients started to send "wide" queries that ret
+Note the divisor is the number of started RPCs, in order to account for in-flight requests.
+
+### 99%-tile latency of unary requests
+```jsoniq
+histogram_quantile(0.99, 
+  sum(rate(grpc_server_handling_seconds_bucket{job="foo",grpc_type="unary"}[5m])) by (grpc_service,le)
+)
+```
+For `job="foo"`, returns an 99%-tile [quantile estimation](https://prometheus.io/docs/practices/histograms/#quantiles)
+of the handling time of RPCs per service. Please note the `5m` rate, this means that the quantile
+estimation will take samples in a rolling `5m` window. When combined with other quantiles
+(e.g. 50%, 90%), this query gives you tremendous insight into the responsiveness of your system 
+(e.g. impact of caching).
+
+### percentage of slow unary queries (>250ms)
+```jsoniq
+100.0 - (
+sum(rate(grpc_server_handling_seconds_bucket{job="foo",grpc_type="unary",le="0.25"}[5m])) by (grpc_service)
+ / 
+sum(rate(grpc_server_handling_seconds_count{job="foo",grpc_type="unary"}[5m])) by (grpc_service)
+) * 100.0
+```
+For `job="foo"` calculate the by-`grpc_service` fraction of slow requests that took longer than `0.25` 
+seconds. This query is relatively complex, since the Prometheus aggregations use `le` (less or equal)
+buckets, meaning that counting "fast" requests fractions is easier. However, simple maths helps.
+This is an example of a query you would like to alert on in your system for SLA violations, 
+e.g. "less than 1% of requests are slower than 250ms".
+
+
+## Status
+
+This code has been used since August 2015 as the basis for monitoring of *production* gRPC micro services  at [Improbable](https://improbable.io).
+
+## License
+
+`go-grpc-prometheus` 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-prometheus/client.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client.go
new file mode 100644
index 0000000..751a4c7
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client.go
@@ -0,0 +1,39 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+// gRPC Prometheus monitoring interceptors for client-side gRPC.
+
+package grpc_prometheus
+
+import (
+	prom "github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	// DefaultClientMetrics is the default instance of ClientMetrics. It is
+	// intended to be used in conjunction the default Prometheus metrics
+	// registry.
+	DefaultClientMetrics = NewClientMetrics()
+
+	// UnaryClientInterceptor is a gRPC client-side interceptor that provides Prometheus monitoring for Unary RPCs.
+	UnaryClientInterceptor = DefaultClientMetrics.UnaryClientInterceptor()
+
+	// StreamClientInterceptor is a gRPC client-side interceptor that provides Prometheus monitoring for Streaming RPCs.
+	StreamClientInterceptor = DefaultClientMetrics.StreamClientInterceptor()
+)
+
+func init() {
+	prom.MustRegister(DefaultClientMetrics.clientStartedCounter)
+	prom.MustRegister(DefaultClientMetrics.clientHandledCounter)
+	prom.MustRegister(DefaultClientMetrics.clientStreamMsgReceived)
+	prom.MustRegister(DefaultClientMetrics.clientStreamMsgSent)
+}
+
+// EnableClientHandlingTimeHistogram turns on recording of handling time of
+// RPCs. Histogram metrics can be very expensive for Prometheus to retain and
+// query. This function acts on the DefaultClientMetrics variable and the
+// default Prometheus metrics registry.
+func EnableClientHandlingTimeHistogram(opts ...HistogramOption) {
+	DefaultClientMetrics.EnableClientHandlingTimeHistogram(opts...)
+	prom.Register(DefaultClientMetrics.clientHandledHistogram)
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_metrics.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_metrics.go
new file mode 100644
index 0000000..9b476f9
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_metrics.go
@@ -0,0 +1,170 @@
+package grpc_prometheus
+
+import (
+	"io"
+
+	prom "github.com/prometheus/client_golang/prometheus"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// ClientMetrics represents a collection of metrics to be registered on a
+// Prometheus metrics registry for a gRPC client.
+type ClientMetrics struct {
+	clientStartedCounter          *prom.CounterVec
+	clientHandledCounter          *prom.CounterVec
+	clientStreamMsgReceived       *prom.CounterVec
+	clientStreamMsgSent           *prom.CounterVec
+	clientHandledHistogramEnabled bool
+	clientHandledHistogramOpts    prom.HistogramOpts
+	clientHandledHistogram        *prom.HistogramVec
+}
+
+// NewClientMetrics returns a ClientMetrics object. Use a new instance of
+// ClientMetrics when not using the default Prometheus metrics registry, for
+// example when wanting to control which metrics are added to a registry as
+// opposed to automatically adding metrics via init functions.
+func NewClientMetrics(counterOpts ...CounterOption) *ClientMetrics {
+	opts := counterOptions(counterOpts)
+	return &ClientMetrics{
+		clientStartedCounter: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_client_started_total",
+				Help: "Total number of RPCs started on the client.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+
+		clientHandledCounter: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_client_handled_total",
+				Help: "Total number of RPCs completed by the client, regardless of success or failure.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method", "grpc_code"}),
+
+		clientStreamMsgReceived: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_client_msg_received_total",
+				Help: "Total number of RPC stream messages received by the client.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+
+		clientStreamMsgSent: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_client_msg_sent_total",
+				Help: "Total number of gRPC stream messages sent by the client.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+
+		clientHandledHistogramEnabled: false,
+		clientHandledHistogramOpts: prom.HistogramOpts{
+			Name:    "grpc_client_handling_seconds",
+			Help:    "Histogram of response latency (seconds) of the gRPC until it is finished by the application.",
+			Buckets: prom.DefBuckets,
+		},
+		clientHandledHistogram: nil,
+	}
+}
+
+// Describe sends the super-set of all possible descriptors of metrics
+// collected by this Collector to the provided channel and returns once
+// the last descriptor has been sent.
+func (m *ClientMetrics) Describe(ch chan<- *prom.Desc) {
+	m.clientStartedCounter.Describe(ch)
+	m.clientHandledCounter.Describe(ch)
+	m.clientStreamMsgReceived.Describe(ch)
+	m.clientStreamMsgSent.Describe(ch)
+	if m.clientHandledHistogramEnabled {
+		m.clientHandledHistogram.Describe(ch)
+	}
+}
+
+// Collect is called by the Prometheus registry when collecting
+// metrics. The implementation sends each collected metric via the
+// provided channel and returns once the last metric has been sent.
+func (m *ClientMetrics) Collect(ch chan<- prom.Metric) {
+	m.clientStartedCounter.Collect(ch)
+	m.clientHandledCounter.Collect(ch)
+	m.clientStreamMsgReceived.Collect(ch)
+	m.clientStreamMsgSent.Collect(ch)
+	if m.clientHandledHistogramEnabled {
+		m.clientHandledHistogram.Collect(ch)
+	}
+}
+
+// EnableClientHandlingTimeHistogram turns on recording of handling time of RPCs.
+// Histogram metrics can be very expensive for Prometheus to retain and query.
+func (m *ClientMetrics) EnableClientHandlingTimeHistogram(opts ...HistogramOption) {
+	for _, o := range opts {
+		o(&m.clientHandledHistogramOpts)
+	}
+	if !m.clientHandledHistogramEnabled {
+		m.clientHandledHistogram = prom.NewHistogramVec(
+			m.clientHandledHistogramOpts,
+			[]string{"grpc_type", "grpc_service", "grpc_method"},
+		)
+	}
+	m.clientHandledHistogramEnabled = true
+}
+
+// UnaryClientInterceptor is a gRPC client-side interceptor that provides Prometheus monitoring for Unary RPCs.
+func (m *ClientMetrics) UnaryClientInterceptor() func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		monitor := newClientReporter(m, Unary, method)
+		monitor.SentMessage()
+		err := invoker(ctx, method, req, reply, cc, opts...)
+		if err != nil {
+			monitor.ReceivedMessage()
+		}
+		st, _ := status.FromError(err)
+		monitor.Handled(st.Code())
+		return err
+	}
+}
+
+// StreamClientInterceptor is a gRPC client-side interceptor that provides Prometheus monitoring for Streaming RPCs.
+func (m *ClientMetrics) StreamClientInterceptor() func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		monitor := newClientReporter(m, clientStreamType(desc), method)
+		clientStream, err := streamer(ctx, desc, cc, method, opts...)
+		if err != nil {
+			st, _ := status.FromError(err)
+			monitor.Handled(st.Code())
+			return nil, err
+		}
+		return &monitoredClientStream{clientStream, monitor}, nil
+	}
+}
+
+func clientStreamType(desc *grpc.StreamDesc) grpcType {
+	if desc.ClientStreams && !desc.ServerStreams {
+		return ClientStream
+	} else if !desc.ClientStreams && desc.ServerStreams {
+		return ServerStream
+	}
+	return BidiStream
+}
+
+// monitoredClientStream wraps grpc.ClientStream allowing each Sent/Recv of message to increment counters.
+type monitoredClientStream struct {
+	grpc.ClientStream
+	monitor *clientReporter
+}
+
+func (s *monitoredClientStream) SendMsg(m interface{}) error {
+	err := s.ClientStream.SendMsg(m)
+	if err == nil {
+		s.monitor.SentMessage()
+	}
+	return err
+}
+
+func (s *monitoredClientStream) RecvMsg(m interface{}) error {
+	err := s.ClientStream.RecvMsg(m)
+	if err == nil {
+		s.monitor.ReceivedMessage()
+	} else if err == io.EOF {
+		s.monitor.Handled(codes.OK)
+	} else {
+		st, _ := status.FromError(err)
+		s.monitor.Handled(st.Code())
+	}
+	return err
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_reporter.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_reporter.go
new file mode 100644
index 0000000..cbf1532
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/client_reporter.go
@@ -0,0 +1,46 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_prometheus
+
+import (
+	"time"
+
+	"google.golang.org/grpc/codes"
+)
+
+type clientReporter struct {
+	metrics     *ClientMetrics
+	rpcType     grpcType
+	serviceName string
+	methodName  string
+	startTime   time.Time
+}
+
+func newClientReporter(m *ClientMetrics, rpcType grpcType, fullMethod string) *clientReporter {
+	r := &clientReporter{
+		metrics: m,
+		rpcType: rpcType,
+	}
+	if r.metrics.clientHandledHistogramEnabled {
+		r.startTime = time.Now()
+	}
+	r.serviceName, r.methodName = splitMethodName(fullMethod)
+	r.metrics.clientStartedCounter.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+	return r
+}
+
+func (r *clientReporter) ReceivedMessage() {
+	r.metrics.clientStreamMsgReceived.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+}
+
+func (r *clientReporter) SentMessage() {
+	r.metrics.clientStreamMsgSent.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+}
+
+func (r *clientReporter) Handled(code codes.Code) {
+	r.metrics.clientHandledCounter.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName, code.String()).Inc()
+	if r.metrics.clientHandledHistogramEnabled {
+		r.metrics.clientHandledHistogram.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Observe(time.Since(r.startTime).Seconds())
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/makefile b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/makefile
new file mode 100644
index 0000000..74c0842
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/makefile
@@ -0,0 +1,16 @@
+SHELL="/bin/bash"
+
+GOFILES_NOVENDOR = $(shell go list ./... | grep -v /vendor/)
+
+all: vet fmt test
+
+fmt:
+	go fmt $(GOFILES_NOVENDOR)
+
+vet:
+	go vet $(GOFILES_NOVENDOR)
+
+test: vet
+	./scripts/test_all.sh
+
+.PHONY: all vet test
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/metric_options.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/metric_options.go
new file mode 100644
index 0000000..9d51aec
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/metric_options.go
@@ -0,0 +1,41 @@
+package grpc_prometheus
+
+import (
+	prom "github.com/prometheus/client_golang/prometheus"
+)
+
+// A CounterOption lets you add options to Counter metrics using With* funcs.
+type CounterOption func(*prom.CounterOpts)
+
+type counterOptions []CounterOption
+
+func (co counterOptions) apply(o prom.CounterOpts) prom.CounterOpts {
+	for _, f := range co {
+		f(&o)
+	}
+	return o
+}
+
+// WithConstLabels allows you to add ConstLabels to Counter metrics.
+func WithConstLabels(labels prom.Labels) CounterOption {
+	return func(o *prom.CounterOpts) {
+		o.ConstLabels = labels
+	}
+}
+
+// A HistogramOption lets you add options to Histogram metrics using With*
+// funcs.
+type HistogramOption func(*prom.HistogramOpts)
+
+// WithHistogramBuckets allows you to specify custom bucket ranges for histograms if EnableHandlingTimeHistogram is on.
+func WithHistogramBuckets(buckets []float64) HistogramOption {
+	return func(o *prom.HistogramOpts) { o.Buckets = buckets }
+}
+
+// WithHistogramConstLabels allows you to add custom ConstLabels to
+// histograms metrics.
+func WithHistogramConstLabels(labels prom.Labels) HistogramOption {
+	return func(o *prom.HistogramOpts) {
+		o.ConstLabels = labels
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server.go
new file mode 100644
index 0000000..322f990
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server.go
@@ -0,0 +1,48 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+// gRPC Prometheus monitoring interceptors for server-side gRPC.
+
+package grpc_prometheus
+
+import (
+	prom "github.com/prometheus/client_golang/prometheus"
+	"google.golang.org/grpc"
+)
+
+var (
+	// DefaultServerMetrics is the default instance of ServerMetrics. It is
+	// intended to be used in conjunction the default Prometheus metrics
+	// registry.
+	DefaultServerMetrics = NewServerMetrics()
+
+	// UnaryServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Unary RPCs.
+	UnaryServerInterceptor = DefaultServerMetrics.UnaryServerInterceptor()
+
+	// StreamServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Streaming RPCs.
+	StreamServerInterceptor = DefaultServerMetrics.StreamServerInterceptor()
+)
+
+func init() {
+	prom.MustRegister(DefaultServerMetrics.serverStartedCounter)
+	prom.MustRegister(DefaultServerMetrics.serverHandledCounter)
+	prom.MustRegister(DefaultServerMetrics.serverStreamMsgReceived)
+	prom.MustRegister(DefaultServerMetrics.serverStreamMsgSent)
+}
+
+// Register takes a gRPC server and pre-initializes all counters to 0. This
+// allows for easier monitoring in Prometheus (no missing metrics), and should
+// be called *after* all services have been registered with the server. This
+// function acts on the DefaultServerMetrics variable.
+func Register(server *grpc.Server) {
+	DefaultServerMetrics.InitializeMetrics(server)
+}
+
+// EnableHandlingTimeHistogram turns on recording of handling time
+// of RPCs. Histogram metrics can be very expensive for Prometheus
+// to retain and query. This function acts on the DefaultServerMetrics
+// variable and the default Prometheus metrics registry.
+func EnableHandlingTimeHistogram(opts ...HistogramOption) {
+	DefaultServerMetrics.EnableHandlingTimeHistogram(opts...)
+	prom.Register(DefaultServerMetrics.serverHandledHistogram)
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_metrics.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_metrics.go
new file mode 100644
index 0000000..5b1467e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_metrics.go
@@ -0,0 +1,185 @@
+package grpc_prometheus
+
+import (
+	prom "github.com/prometheus/client_golang/prometheus"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/status"
+)
+
+// ServerMetrics represents a collection of metrics to be registered on a
+// Prometheus metrics registry for a gRPC server.
+type ServerMetrics struct {
+	serverStartedCounter          *prom.CounterVec
+	serverHandledCounter          *prom.CounterVec
+	serverStreamMsgReceived       *prom.CounterVec
+	serverStreamMsgSent           *prom.CounterVec
+	serverHandledHistogramEnabled bool
+	serverHandledHistogramOpts    prom.HistogramOpts
+	serverHandledHistogram        *prom.HistogramVec
+}
+
+// NewServerMetrics returns a ServerMetrics object. Use a new instance of
+// ServerMetrics when not using the default Prometheus metrics registry, for
+// example when wanting to control which metrics are added to a registry as
+// opposed to automatically adding metrics via init functions.
+func NewServerMetrics(counterOpts ...CounterOption) *ServerMetrics {
+	opts := counterOptions(counterOpts)
+	return &ServerMetrics{
+		serverStartedCounter: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_server_started_total",
+				Help: "Total number of RPCs started on the server.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+		serverHandledCounter: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_server_handled_total",
+				Help: "Total number of RPCs completed on the server, regardless of success or failure.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method", "grpc_code"}),
+		serverStreamMsgReceived: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_server_msg_received_total",
+				Help: "Total number of RPC stream messages received on the server.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+		serverStreamMsgSent: prom.NewCounterVec(
+			opts.apply(prom.CounterOpts{
+				Name: "grpc_server_msg_sent_total",
+				Help: "Total number of gRPC stream messages sent by the server.",
+			}), []string{"grpc_type", "grpc_service", "grpc_method"}),
+		serverHandledHistogramEnabled: false,
+		serverHandledHistogramOpts: prom.HistogramOpts{
+			Name:    "grpc_server_handling_seconds",
+			Help:    "Histogram of response latency (seconds) of gRPC that had been application-level handled by the server.",
+			Buckets: prom.DefBuckets,
+		},
+		serverHandledHistogram: nil,
+	}
+}
+
+// EnableHandlingTimeHistogram enables histograms being registered when
+// registering the ServerMetrics on a Prometheus registry. Histograms can be
+// expensive on Prometheus servers. It takes options to configure histogram
+// options such as the defined buckets.
+func (m *ServerMetrics) EnableHandlingTimeHistogram(opts ...HistogramOption) {
+	for _, o := range opts {
+		o(&m.serverHandledHistogramOpts)
+	}
+	if !m.serverHandledHistogramEnabled {
+		m.serverHandledHistogram = prom.NewHistogramVec(
+			m.serverHandledHistogramOpts,
+			[]string{"grpc_type", "grpc_service", "grpc_method"},
+		)
+	}
+	m.serverHandledHistogramEnabled = true
+}
+
+// Describe sends the super-set of all possible descriptors of metrics
+// collected by this Collector to the provided channel and returns once
+// the last descriptor has been sent.
+func (m *ServerMetrics) Describe(ch chan<- *prom.Desc) {
+	m.serverStartedCounter.Describe(ch)
+	m.serverHandledCounter.Describe(ch)
+	m.serverStreamMsgReceived.Describe(ch)
+	m.serverStreamMsgSent.Describe(ch)
+	if m.serverHandledHistogramEnabled {
+		m.serverHandledHistogram.Describe(ch)
+	}
+}
+
+// Collect is called by the Prometheus registry when collecting
+// metrics. The implementation sends each collected metric via the
+// provided channel and returns once the last metric has been sent.
+func (m *ServerMetrics) Collect(ch chan<- prom.Metric) {
+	m.serverStartedCounter.Collect(ch)
+	m.serverHandledCounter.Collect(ch)
+	m.serverStreamMsgReceived.Collect(ch)
+	m.serverStreamMsgSent.Collect(ch)
+	if m.serverHandledHistogramEnabled {
+		m.serverHandledHistogram.Collect(ch)
+	}
+}
+
+// UnaryServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Unary RPCs.
+func (m *ServerMetrics) UnaryServerInterceptor() func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		monitor := newServerReporter(m, Unary, info.FullMethod)
+		monitor.ReceivedMessage()
+		resp, err := handler(ctx, req)
+		st, _ := status.FromError(err)
+		monitor.Handled(st.Code())
+		if err == nil {
+			monitor.SentMessage()
+		}
+		return resp, err
+	}
+}
+
+// StreamServerInterceptor is a gRPC server-side interceptor that provides Prometheus monitoring for Streaming RPCs.
+func (m *ServerMetrics) StreamServerInterceptor() func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		monitor := newServerReporter(m, streamRPCType(info), info.FullMethod)
+		err := handler(srv, &monitoredServerStream{ss, monitor})
+		st, _ := status.FromError(err)
+		monitor.Handled(st.Code())
+		return err
+	}
+}
+
+// InitializeMetrics initializes all metrics, with their appropriate null
+// value, for all gRPC methods registered on a gRPC server. This is useful, to
+// ensure that all metrics exist when collecting and querying.
+func (m *ServerMetrics) InitializeMetrics(server *grpc.Server) {
+	serviceInfo := server.GetServiceInfo()
+	for serviceName, info := range serviceInfo {
+		for _, mInfo := range info.Methods {
+			preRegisterMethod(m, serviceName, &mInfo)
+		}
+	}
+}
+
+func streamRPCType(info *grpc.StreamServerInfo) grpcType {
+	if info.IsClientStream && !info.IsServerStream {
+		return ClientStream
+	} else if !info.IsClientStream && info.IsServerStream {
+		return ServerStream
+	}
+	return BidiStream
+}
+
+// monitoredStream wraps grpc.ServerStream allowing each Sent/Recv of message to increment counters.
+type monitoredServerStream struct {
+	grpc.ServerStream
+	monitor *serverReporter
+}
+
+func (s *monitoredServerStream) SendMsg(m interface{}) error {
+	err := s.ServerStream.SendMsg(m)
+	if err == nil {
+		s.monitor.SentMessage()
+	}
+	return err
+}
+
+func (s *monitoredServerStream) RecvMsg(m interface{}) error {
+	err := s.ServerStream.RecvMsg(m)
+	if err == nil {
+		s.monitor.ReceivedMessage()
+	}
+	return err
+}
+
+// preRegisterMethod is invoked on Register of a Server, allowing all gRPC services labels to be pre-populated.
+func preRegisterMethod(metrics *ServerMetrics, serviceName string, mInfo *grpc.MethodInfo) {
+	methodName := mInfo.Name
+	methodType := string(typeFromMethodInfo(mInfo))
+	// These are just references (no increments), as just referencing will create the labels but not set values.
+	metrics.serverStartedCounter.GetMetricWithLabelValues(methodType, serviceName, methodName)
+	metrics.serverStreamMsgReceived.GetMetricWithLabelValues(methodType, serviceName, methodName)
+	metrics.serverStreamMsgSent.GetMetricWithLabelValues(methodType, serviceName, methodName)
+	if metrics.serverHandledHistogramEnabled {
+		metrics.serverHandledHistogram.GetMetricWithLabelValues(methodType, serviceName, methodName)
+	}
+	for _, code := range allCodes {
+		metrics.serverHandledCounter.GetMetricWithLabelValues(methodType, serviceName, methodName, code.String())
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_reporter.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_reporter.go
new file mode 100644
index 0000000..aa9db54
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/server_reporter.go
@@ -0,0 +1,46 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_prometheus
+
+import (
+	"time"
+
+	"google.golang.org/grpc/codes"
+)
+
+type serverReporter struct {
+	metrics     *ServerMetrics
+	rpcType     grpcType
+	serviceName string
+	methodName  string
+	startTime   time.Time
+}
+
+func newServerReporter(m *ServerMetrics, rpcType grpcType, fullMethod string) *serverReporter {
+	r := &serverReporter{
+		metrics: m,
+		rpcType: rpcType,
+	}
+	if r.metrics.serverHandledHistogramEnabled {
+		r.startTime = time.Now()
+	}
+	r.serviceName, r.methodName = splitMethodName(fullMethod)
+	r.metrics.serverStartedCounter.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+	return r
+}
+
+func (r *serverReporter) ReceivedMessage() {
+	r.metrics.serverStreamMsgReceived.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+}
+
+func (r *serverReporter) SentMessage() {
+	r.metrics.serverStreamMsgSent.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Inc()
+}
+
+func (r *serverReporter) Handled(code codes.Code) {
+	r.metrics.serverHandledCounter.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName, code.String()).Inc()
+	if r.metrics.serverHandledHistogramEnabled {
+		r.metrics.serverHandledHistogram.WithLabelValues(string(r.rpcType), r.serviceName, r.methodName).Observe(time.Since(r.startTime).Seconds())
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/util.go b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/util.go
new file mode 100644
index 0000000..7987de3
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-prometheus/util.go
@@ -0,0 +1,50 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_prometheus
+
+import (
+	"strings"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+)
+
+type grpcType string
+
+const (
+	Unary        grpcType = "unary"
+	ClientStream grpcType = "client_stream"
+	ServerStream grpcType = "server_stream"
+	BidiStream   grpcType = "bidi_stream"
+)
+
+var (
+	allCodes = []codes.Code{
+		codes.OK, codes.Canceled, codes.Unknown, codes.InvalidArgument, codes.DeadlineExceeded, codes.NotFound,
+		codes.AlreadyExists, codes.PermissionDenied, codes.Unauthenticated, codes.ResourceExhausted,
+		codes.FailedPrecondition, codes.Aborted, codes.OutOfRange, codes.Unimplemented, codes.Internal,
+		codes.Unavailable, codes.DataLoss,
+	}
+)
+
+func splitMethodName(fullMethodName string) (string, string) {
+	fullMethodName = strings.TrimPrefix(fullMethodName, "/") // remove leading slash
+	if i := strings.Index(fullMethodName, "/"); i >= 0 {
+		return fullMethodName[:i], fullMethodName[i+1:]
+	}
+	return "unknown", "unknown"
+}
+
+func typeFromMethodInfo(mInfo *grpc.MethodInfo) grpcType {
+	if !mInfo.IsClientStream && !mInfo.IsServerStream {
+		return Unary
+	}
+	if mInfo.IsClientStream && !mInfo.IsServerStream {
+		return ClientStream
+	}
+	if !mInfo.IsClientStream && mInfo.IsServerStream {
+		return ServerStream
+	}
+	return BidiStream
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt b/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt
new file mode 100644
index 0000000..3645162
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/LICENSE.txt
@@ -0,0 +1,27 @@
+Copyright (c) 2015, Gengo, Inc.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+
+    * Neither the name of Gengo, Inc. nor the names of its
+      contributors may be used to endorse or promote products derived from this
+      software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/BUILD.bazel
new file mode 100644
index 0000000..76cafe6
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/BUILD.bazel
@@ -0,0 +1,22 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+
+package(default_visibility = ["//visibility:public"])
+
+proto_library(
+    name = "internal_proto",
+    srcs = ["stream_chunk.proto"],
+    deps = ["@com_google_protobuf//:any_proto"],
+)
+
+go_proto_library(
+    name = "internal_go_proto",
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/internal",
+    proto = ":internal_proto",
+)
+
+go_library(
+    name = "go_default_library",
+    embed = [":internal_go_proto"],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/internal",
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.pb.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.pb.go
new file mode 100644
index 0000000..8858f06
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.pb.go
@@ -0,0 +1,118 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// source: internal/stream_chunk.proto
+
+package internal
+
+import proto "github.com/golang/protobuf/proto"
+import fmt "fmt"
+import math "math"
+import any "github.com/golang/protobuf/ptypes/any"
+
+// 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
+
+// StreamError is a response type which is returned when
+// streaming rpc returns an error.
+type StreamError struct {
+	GrpcCode             int32      `protobuf:"varint,1,opt,name=grpc_code,json=grpcCode,proto3" json:"grpc_code,omitempty"`
+	HttpCode             int32      `protobuf:"varint,2,opt,name=http_code,json=httpCode,proto3" json:"http_code,omitempty"`
+	Message              string     `protobuf:"bytes,3,opt,name=message,proto3" json:"message,omitempty"`
+	HttpStatus           string     `protobuf:"bytes,4,opt,name=http_status,json=httpStatus,proto3" json:"http_status,omitempty"`
+	Details              []*any.Any `protobuf:"bytes,5,rep,name=details,proto3" json:"details,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}   `json:"-"`
+	XXX_unrecognized     []byte     `json:"-"`
+	XXX_sizecache        int32      `json:"-"`
+}
+
+func (m *StreamError) Reset()         { *m = StreamError{} }
+func (m *StreamError) String() string { return proto.CompactTextString(m) }
+func (*StreamError) ProtoMessage()    {}
+func (*StreamError) Descriptor() ([]byte, []int) {
+	return fileDescriptor_stream_chunk_a2afb657504565d7, []int{0}
+}
+func (m *StreamError) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_StreamError.Unmarshal(m, b)
+}
+func (m *StreamError) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_StreamError.Marshal(b, m, deterministic)
+}
+func (dst *StreamError) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_StreamError.Merge(dst, src)
+}
+func (m *StreamError) XXX_Size() int {
+	return xxx_messageInfo_StreamError.Size(m)
+}
+func (m *StreamError) XXX_DiscardUnknown() {
+	xxx_messageInfo_StreamError.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_StreamError proto.InternalMessageInfo
+
+func (m *StreamError) GetGrpcCode() int32 {
+	if m != nil {
+		return m.GrpcCode
+	}
+	return 0
+}
+
+func (m *StreamError) GetHttpCode() int32 {
+	if m != nil {
+		return m.HttpCode
+	}
+	return 0
+}
+
+func (m *StreamError) GetMessage() string {
+	if m != nil {
+		return m.Message
+	}
+	return ""
+}
+
+func (m *StreamError) GetHttpStatus() string {
+	if m != nil {
+		return m.HttpStatus
+	}
+	return ""
+}
+
+func (m *StreamError) GetDetails() []*any.Any {
+	if m != nil {
+		return m.Details
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterType((*StreamError)(nil), "grpc.gateway.runtime.StreamError")
+}
+
+func init() {
+	proto.RegisterFile("internal/stream_chunk.proto", fileDescriptor_stream_chunk_a2afb657504565d7)
+}
+
+var fileDescriptor_stream_chunk_a2afb657504565d7 = []byte{
+	// 223 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x34, 0x90, 0x41, 0x4e, 0xc3, 0x30,
+	0x10, 0x45, 0x15, 0x4a, 0x69, 0x3b, 0xd9, 0x45, 0x5d, 0x18, 0xba, 0x20, 0x62, 0x95, 0x95, 0x23,
+	0xc1, 0x09, 0x00, 0x71, 0x81, 0x74, 0xc7, 0xa6, 0x9a, 0x26, 0x83, 0x13, 0x91, 0xd8, 0xd1, 0x78,
+	0x22, 0x94, 0x6b, 0x71, 0xc2, 0xca, 0x8e, 0xb2, 0xf4, 0x7b, 0x7f, 0xbe, 0xbe, 0x0c, 0xa7, 0xce,
+	0x0a, 0xb1, 0xc5, 0xbe, 0xf4, 0xc2, 0x84, 0xc3, 0xa5, 0x6e, 0x27, 0xfb, 0xab, 0x47, 0x76, 0xe2,
+	0xb2, 0xa3, 0xe1, 0xb1, 0xd6, 0x06, 0x85, 0xfe, 0x70, 0xd6, 0x3c, 0x59, 0xe9, 0x06, 0x7a, 0x7a,
+	0x34, 0xce, 0x99, 0x9e, 0xca, 0x98, 0xb9, 0x4e, 0x3f, 0x25, 0xda, 0x79, 0x39, 0x78, 0xf9, 0x4f,
+	0x20, 0x3d, 0xc7, 0x9e, 0x2f, 0x66, 0xc7, 0xd9, 0x09, 0x0e, 0xa1, 0xe2, 0x52, 0xbb, 0x86, 0x54,
+	0x92, 0x27, 0xc5, 0xb6, 0xda, 0x07, 0xf0, 0xe9, 0x1a, 0x0a, 0xb2, 0x15, 0x19, 0x17, 0x79, 0xb7,
+	0xc8, 0x00, 0xa2, 0x54, 0xb0, 0x1b, 0xc8, 0x7b, 0x34, 0xa4, 0x36, 0x79, 0x52, 0x1c, 0xaa, 0xf5,
+	0x99, 0x3d, 0x43, 0x1a, 0xcf, 0xbc, 0xa0, 0x4c, 0x5e, 0xdd, 0x47, 0x0b, 0x01, 0x9d, 0x23, 0xc9,
+	0x34, 0xec, 0x1a, 0x12, 0xec, 0x7a, 0xaf, 0xb6, 0xf9, 0xa6, 0x48, 0x5f, 0x8f, 0x7a, 0x59, 0xac,
+	0xd7, 0xc5, 0xfa, 0xdd, 0xce, 0xd5, 0x1a, 0xfa, 0x80, 0xef, 0xfd, 0xfa, 0x09, 0xd7, 0x87, 0x18,
+	0x79, 0xbb, 0x05, 0x00, 0x00, 0xff, 0xff, 0x0d, 0x7d, 0xa5, 0x18, 0x17, 0x01, 0x00, 0x00,
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.proto b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.proto
new file mode 100644
index 0000000..55f42ce
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/internal/stream_chunk.proto
@@ -0,0 +1,15 @@
+syntax = "proto3";
+package grpc.gateway.runtime;
+option go_package = "internal";
+
+import "google/protobuf/any.proto";
+
+// StreamError is a response type which is returned when
+// streaming rpc returns an error.
+message StreamError {
+	int32 grpc_code = 1;
+	int32 http_code = 2;
+	string message = 3;
+	string http_status = 4;
+	repeated google.protobuf.Any details = 5;
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel
new file mode 100644
index 0000000..2086222
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/BUILD.bazel
@@ -0,0 +1,84 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+package(default_visibility = ["//visibility:public"])
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "context.go",
+        "convert.go",
+        "doc.go",
+        "errors.go",
+        "fieldmask.go",
+        "handler.go",
+        "marshal_httpbodyproto.go",
+        "marshal_json.go",
+        "marshal_jsonpb.go",
+        "marshal_proto.go",
+        "marshaler.go",
+        "marshaler_registry.go",
+        "mux.go",
+        "pattern.go",
+        "proto2_convert.go",
+        "proto_errors.go",
+        "query.go",
+    ],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/runtime",
+    deps = [
+        "//internal:go_default_library",
+        "//utilities:go_default_library",
+        "@com_github_golang_protobuf//jsonpb:go_default_library_gen",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_golang_protobuf//protoc-gen-go/generator:go_default_library_gen",
+        "@go_googleapis//google/api:httpbody_go_proto",
+        "@io_bazel_rules_go//proto/wkt:any_go_proto",
+        "@io_bazel_rules_go//proto/wkt:duration_go_proto",
+        "@io_bazel_rules_go//proto/wkt:field_mask_go_proto",
+        "@io_bazel_rules_go//proto/wkt:timestamp_go_proto",
+        "@io_bazel_rules_go//proto/wkt:wrappers_go_proto",
+        "@org_golang_google_grpc//codes:go_default_library",
+        "@org_golang_google_grpc//grpclog:go_default_library",
+        "@org_golang_google_grpc//metadata:go_default_library",
+        "@org_golang_google_grpc//status:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    size = "small",
+    srcs = [
+        "context_test.go",
+        "errors_test.go",
+        "fieldmask_test.go",
+        "handler_test.go",
+        "marshal_httpbodyproto_test.go",
+        "marshal_json_test.go",
+        "marshal_jsonpb_test.go",
+        "marshal_proto_test.go",
+        "marshaler_registry_test.go",
+        "mux_test.go",
+        "pattern_test.go",
+        "query_test.go",
+    ],
+    embed = [":go_default_library"],
+    deps = [
+        "//examples/proto/examplepb:go_default_library",
+        "//internal:go_default_library",
+        "//utilities:go_default_library",
+        "@com_github_golang_protobuf//jsonpb:go_default_library_gen",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_golang_protobuf//ptypes:go_default_library_gen",
+        "@go_googleapis//google/api:httpbody_go_proto",
+        "@go_googleapis//google/rpc:errdetails_go_proto",
+        "@io_bazel_rules_go//proto/wkt:duration_go_proto",
+        "@io_bazel_rules_go//proto/wkt:empty_go_proto",
+        "@io_bazel_rules_go//proto/wkt:field_mask_go_proto",
+        "@io_bazel_rules_go//proto/wkt:struct_go_proto",
+        "@io_bazel_rules_go//proto/wkt:timestamp_go_proto",
+        "@io_bazel_rules_go//proto/wkt:wrappers_go_proto",
+        "@org_golang_google_grpc//:go_default_library",
+        "@org_golang_google_grpc//codes:go_default_library",
+        "@org_golang_google_grpc//metadata:go_default_library",
+        "@org_golang_google_grpc//status:go_default_library",
+    ],
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go
new file mode 100644
index 0000000..896057e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/context.go
@@ -0,0 +1,210 @@
+package runtime
+
+import (
+	"context"
+	"encoding/base64"
+	"fmt"
+	"net"
+	"net/http"
+	"net/textproto"
+	"strconv"
+	"strings"
+	"time"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// MetadataHeaderPrefix is the http prefix that represents custom metadata
+// parameters to or from a gRPC call.
+const MetadataHeaderPrefix = "Grpc-Metadata-"
+
+// MetadataPrefix is prepended to permanent HTTP header keys (as specified
+// by the IANA) when added to the gRPC context.
+const MetadataPrefix = "grpcgateway-"
+
+// MetadataTrailerPrefix is prepended to gRPC metadata as it is converted to
+// HTTP headers in a response handled by grpc-gateway
+const MetadataTrailerPrefix = "Grpc-Trailer-"
+
+const metadataGrpcTimeout = "Grpc-Timeout"
+const metadataHeaderBinarySuffix = "-Bin"
+
+const xForwardedFor = "X-Forwarded-For"
+const xForwardedHost = "X-Forwarded-Host"
+
+var (
+	// DefaultContextTimeout is used for gRPC call context.WithTimeout whenever a Grpc-Timeout inbound
+	// header isn't present. If the value is 0 the sent `context` will not have a timeout.
+	DefaultContextTimeout = 0 * time.Second
+)
+
+func decodeBinHeader(v string) ([]byte, error) {
+	if len(v)%4 == 0 {
+		// Input was padded, or padding was not necessary.
+		return base64.StdEncoding.DecodeString(v)
+	}
+	return base64.RawStdEncoding.DecodeString(v)
+}
+
+/*
+AnnotateContext adds context information such as metadata from the request.
+
+At a minimum, the RemoteAddr is included in the fashion of "X-Forwarded-For",
+except that the forwarded destination is not another HTTP service but rather
+a gRPC service.
+*/
+func AnnotateContext(ctx context.Context, mux *ServeMux, req *http.Request) (context.Context, error) {
+	var pairs []string
+	timeout := DefaultContextTimeout
+	if tm := req.Header.Get(metadataGrpcTimeout); tm != "" {
+		var err error
+		timeout, err = timeoutDecode(tm)
+		if err != nil {
+			return nil, status.Errorf(codes.InvalidArgument, "invalid grpc-timeout: %s", tm)
+		}
+	}
+
+	for key, vals := range req.Header {
+		for _, val := range vals {
+			key = textproto.CanonicalMIMEHeaderKey(key)
+			// For backwards-compatibility, pass through 'authorization' header with no prefix.
+			if key == "Authorization" {
+				pairs = append(pairs, "authorization", val)
+			}
+			if h, ok := mux.incomingHeaderMatcher(key); ok {
+				// Handles "-bin" metadata in grpc, since grpc will do another base64
+				// encode before sending to server, we need to decode it first.
+				if strings.HasSuffix(key, metadataHeaderBinarySuffix) {
+					b, err := decodeBinHeader(val)
+					if err != nil {
+						return nil, status.Errorf(codes.InvalidArgument, "invalid binary header %s: %s", key, err)
+					}
+
+					val = string(b)
+				}
+				pairs = append(pairs, h, val)
+			}
+		}
+	}
+	if host := req.Header.Get(xForwardedHost); host != "" {
+		pairs = append(pairs, strings.ToLower(xForwardedHost), host)
+	} else if req.Host != "" {
+		pairs = append(pairs, strings.ToLower(xForwardedHost), req.Host)
+	}
+
+	if addr := req.RemoteAddr; addr != "" {
+		if remoteIP, _, err := net.SplitHostPort(addr); err == nil {
+			if fwd := req.Header.Get(xForwardedFor); fwd == "" {
+				pairs = append(pairs, strings.ToLower(xForwardedFor), remoteIP)
+			} else {
+				pairs = append(pairs, strings.ToLower(xForwardedFor), fmt.Sprintf("%s, %s", fwd, remoteIP))
+			}
+		} else {
+			grpclog.Infof("invalid remote addr: %s", addr)
+		}
+	}
+
+	if timeout != 0 {
+		ctx, _ = context.WithTimeout(ctx, timeout)
+	}
+	if len(pairs) == 0 {
+		return ctx, nil
+	}
+	md := metadata.Pairs(pairs...)
+	for _, mda := range mux.metadataAnnotators {
+		md = metadata.Join(md, mda(ctx, req))
+	}
+	return metadata.NewOutgoingContext(ctx, md), nil
+}
+
+// ServerMetadata consists of metadata sent from gRPC server.
+type ServerMetadata struct {
+	HeaderMD  metadata.MD
+	TrailerMD metadata.MD
+}
+
+type serverMetadataKey struct{}
+
+// NewServerMetadataContext creates a new context with ServerMetadata
+func NewServerMetadataContext(ctx context.Context, md ServerMetadata) context.Context {
+	return context.WithValue(ctx, serverMetadataKey{}, md)
+}
+
+// ServerMetadataFromContext returns the ServerMetadata in ctx
+func ServerMetadataFromContext(ctx context.Context) (md ServerMetadata, ok bool) {
+	md, ok = ctx.Value(serverMetadataKey{}).(ServerMetadata)
+	return
+}
+
+func timeoutDecode(s string) (time.Duration, error) {
+	size := len(s)
+	if size < 2 {
+		return 0, fmt.Errorf("timeout string is too short: %q", s)
+	}
+	d, ok := timeoutUnitToDuration(s[size-1])
+	if !ok {
+		return 0, fmt.Errorf("timeout unit is not recognized: %q", s)
+	}
+	t, err := strconv.ParseInt(s[:size-1], 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	return d * time.Duration(t), nil
+}
+
+func timeoutUnitToDuration(u uint8) (d time.Duration, ok bool) {
+	switch u {
+	case 'H':
+		return time.Hour, true
+	case 'M':
+		return time.Minute, true
+	case 'S':
+		return time.Second, true
+	case 'm':
+		return time.Millisecond, true
+	case 'u':
+		return time.Microsecond, true
+	case 'n':
+		return time.Nanosecond, true
+	default:
+	}
+	return
+}
+
+// isPermanentHTTPHeader checks whether hdr belongs to the list of
+// permenant request headers maintained by IANA.
+// http://www.iana.org/assignments/message-headers/message-headers.xml
+func isPermanentHTTPHeader(hdr string) bool {
+	switch hdr {
+	case
+		"Accept",
+		"Accept-Charset",
+		"Accept-Language",
+		"Accept-Ranges",
+		"Authorization",
+		"Cache-Control",
+		"Content-Type",
+		"Cookie",
+		"Date",
+		"Expect",
+		"From",
+		"Host",
+		"If-Match",
+		"If-Modified-Since",
+		"If-None-Match",
+		"If-Schedule-Tag-Match",
+		"If-Unmodified-Since",
+		"Max-Forwards",
+		"Origin",
+		"Pragma",
+		"Referer",
+		"User-Agent",
+		"Via",
+		"Warning":
+		return true
+	}
+	return false
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go
new file mode 100644
index 0000000..a5b3bd6
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/convert.go
@@ -0,0 +1,312 @@
+package runtime
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/ptypes/duration"
+	"github.com/golang/protobuf/ptypes/timestamp"
+	"github.com/golang/protobuf/ptypes/wrappers"
+)
+
+// String just returns the given string.
+// It is just for compatibility to other types.
+func String(val string) (string, error) {
+	return val, nil
+}
+
+// StringSlice converts 'val' where individual strings are separated by
+// 'sep' into a string slice.
+func StringSlice(val, sep string) ([]string, error) {
+	return strings.Split(val, sep), nil
+}
+
+// Bool converts the given string representation of a boolean value into bool.
+func Bool(val string) (bool, error) {
+	return strconv.ParseBool(val)
+}
+
+// BoolSlice converts 'val' where individual booleans are separated by
+// 'sep' into a bool slice.
+func BoolSlice(val, sep string) ([]bool, error) {
+	s := strings.Split(val, sep)
+	values := make([]bool, len(s))
+	for i, v := range s {
+		value, err := Bool(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Float64 converts the given string representation into representation of a floating point number into float64.
+func Float64(val string) (float64, error) {
+	return strconv.ParseFloat(val, 64)
+}
+
+// Float64Slice converts 'val' where individual floating point numbers are separated by
+// 'sep' into a float64 slice.
+func Float64Slice(val, sep string) ([]float64, error) {
+	s := strings.Split(val, sep)
+	values := make([]float64, len(s))
+	for i, v := range s {
+		value, err := Float64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Float32 converts the given string representation of a floating point number into float32.
+func Float32(val string) (float32, error) {
+	f, err := strconv.ParseFloat(val, 32)
+	if err != nil {
+		return 0, err
+	}
+	return float32(f), nil
+}
+
+// Float32Slice converts 'val' where individual floating point numbers are separated by
+// 'sep' into a float32 slice.
+func Float32Slice(val, sep string) ([]float32, error) {
+	s := strings.Split(val, sep)
+	values := make([]float32, len(s))
+	for i, v := range s {
+		value, err := Float32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Int64 converts the given string representation of an integer into int64.
+func Int64(val string) (int64, error) {
+	return strconv.ParseInt(val, 0, 64)
+}
+
+// Int64Slice converts 'val' where individual integers are separated by
+// 'sep' into a int64 slice.
+func Int64Slice(val, sep string) ([]int64, error) {
+	s := strings.Split(val, sep)
+	values := make([]int64, len(s))
+	for i, v := range s {
+		value, err := Int64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Int32 converts the given string representation of an integer into int32.
+func Int32(val string) (int32, error) {
+	i, err := strconv.ParseInt(val, 0, 32)
+	if err != nil {
+		return 0, err
+	}
+	return int32(i), nil
+}
+
+// Int32Slice converts 'val' where individual integers are separated by
+// 'sep' into a int32 slice.
+func Int32Slice(val, sep string) ([]int32, error) {
+	s := strings.Split(val, sep)
+	values := make([]int32, len(s))
+	for i, v := range s {
+		value, err := Int32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Uint64 converts the given string representation of an integer into uint64.
+func Uint64(val string) (uint64, error) {
+	return strconv.ParseUint(val, 0, 64)
+}
+
+// Uint64Slice converts 'val' where individual integers are separated by
+// 'sep' into a uint64 slice.
+func Uint64Slice(val, sep string) ([]uint64, error) {
+	s := strings.Split(val, sep)
+	values := make([]uint64, len(s))
+	for i, v := range s {
+		value, err := Uint64(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Uint32 converts the given string representation of an integer into uint32.
+func Uint32(val string) (uint32, error) {
+	i, err := strconv.ParseUint(val, 0, 32)
+	if err != nil {
+		return 0, err
+	}
+	return uint32(i), nil
+}
+
+// Uint32Slice converts 'val' where individual integers are separated by
+// 'sep' into a uint32 slice.
+func Uint32Slice(val, sep string) ([]uint32, error) {
+	s := strings.Split(val, sep)
+	values := make([]uint32, len(s))
+	for i, v := range s {
+		value, err := Uint32(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Bytes converts the given string representation of a byte sequence into a slice of bytes
+// A bytes sequence is encoded in URL-safe base64 without padding
+func Bytes(val string) ([]byte, error) {
+	b, err := base64.StdEncoding.DecodeString(val)
+	if err != nil {
+		b, err = base64.URLEncoding.DecodeString(val)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return b, nil
+}
+
+// BytesSlice converts 'val' where individual bytes sequences, encoded in URL-safe
+// base64 without padding, are separated by 'sep' into a slice of bytes slices slice.
+func BytesSlice(val, sep string) ([][]byte, error) {
+	s := strings.Split(val, sep)
+	values := make([][]byte, len(s))
+	for i, v := range s {
+		value, err := Bytes(v)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+// Timestamp converts the given RFC3339 formatted string into a timestamp.Timestamp.
+func Timestamp(val string) (*timestamp.Timestamp, error) {
+	var r *timestamp.Timestamp
+	err := jsonpb.UnmarshalString(val, r)
+	return r, err
+}
+
+// Duration converts the given string into a timestamp.Duration.
+func Duration(val string) (*duration.Duration, error) {
+	var r *duration.Duration
+	err := jsonpb.UnmarshalString(val, r)
+	return r, err
+}
+
+// Enum converts the given string into an int32 that should be type casted into the
+// correct enum proto type.
+func Enum(val string, enumValMap map[string]int32) (int32, error) {
+	e, ok := enumValMap[val]
+	if ok {
+		return e, nil
+	}
+
+	i, err := Int32(val)
+	if err != nil {
+		return 0, fmt.Errorf("%s is not valid", val)
+	}
+	for _, v := range enumValMap {
+		if v == i {
+			return i, nil
+		}
+	}
+	return 0, fmt.Errorf("%s is not valid", val)
+}
+
+// EnumSlice converts 'val' where individual enums are separated by 'sep'
+// into a int32 slice. Each individual int32 should be type casted into the
+// correct enum proto type.
+func EnumSlice(val, sep string, enumValMap map[string]int32) ([]int32, error) {
+	s := strings.Split(val, sep)
+	values := make([]int32, len(s))
+	for i, v := range s {
+		value, err := Enum(v, enumValMap)
+		if err != nil {
+			return values, err
+		}
+		values[i] = value
+	}
+	return values, nil
+}
+
+/*
+	Support fot google.protobuf.wrappers on top of primitive types
+*/
+
+// StringValue well-known type support as wrapper around string type
+func StringValue(val string) (*wrappers.StringValue, error) {
+	return &wrappers.StringValue{Value: val}, nil
+}
+
+// FloatValue well-known type support as wrapper around float32 type
+func FloatValue(val string) (*wrappers.FloatValue, error) {
+	parsedVal, err := Float32(val)
+	return &wrappers.FloatValue{Value: parsedVal}, err
+}
+
+// DoubleValue well-known type support as wrapper around float64 type
+func DoubleValue(val string) (*wrappers.DoubleValue, error) {
+	parsedVal, err := Float64(val)
+	return &wrappers.DoubleValue{Value: parsedVal}, err
+}
+
+// BoolValue well-known type support as wrapper around bool type
+func BoolValue(val string) (*wrappers.BoolValue, error) {
+	parsedVal, err := Bool(val)
+	return &wrappers.BoolValue{Value: parsedVal}, err
+}
+
+// Int32Value well-known type support as wrapper around int32 type
+func Int32Value(val string) (*wrappers.Int32Value, error) {
+	parsedVal, err := Int32(val)
+	return &wrappers.Int32Value{Value: parsedVal}, err
+}
+
+// UInt32Value well-known type support as wrapper around uint32 type
+func UInt32Value(val string) (*wrappers.UInt32Value, error) {
+	parsedVal, err := Uint32(val)
+	return &wrappers.UInt32Value{Value: parsedVal}, err
+}
+
+// Int64Value well-known type support as wrapper around int64 type
+func Int64Value(val string) (*wrappers.Int64Value, error) {
+	parsedVal, err := Int64(val)
+	return &wrappers.Int64Value{Value: parsedVal}, err
+}
+
+// UInt64Value well-known type support as wrapper around uint64 type
+func UInt64Value(val string) (*wrappers.UInt64Value, error) {
+	parsedVal, err := Uint64(val)
+	return &wrappers.UInt64Value{Value: parsedVal}, err
+}
+
+// BytesValue well-known type support as wrapper around bytes[] type
+func BytesValue(val string) (*wrappers.BytesValue, error) {
+	parsedVal, err := Bytes(val)
+	return &wrappers.BytesValue{Value: parsedVal}, err
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go
new file mode 100644
index 0000000..b6e5ddf
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/doc.go
@@ -0,0 +1,5 @@
+/*
+Package runtime contains runtime helper functions used by
+servers which protoc-gen-grpc-gateway generates.
+*/
+package runtime
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
new file mode 100644
index 0000000..ad94578
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
@@ -0,0 +1,146 @@
+package runtime
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// HTTPStatusFromCode converts a gRPC error code into the corresponding HTTP response status.
+// See: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
+func HTTPStatusFromCode(code codes.Code) int {
+	switch code {
+	case codes.OK:
+		return http.StatusOK
+	case codes.Canceled:
+		return http.StatusRequestTimeout
+	case codes.Unknown:
+		return http.StatusInternalServerError
+	case codes.InvalidArgument:
+		return http.StatusBadRequest
+	case codes.DeadlineExceeded:
+		return http.StatusGatewayTimeout
+	case codes.NotFound:
+		return http.StatusNotFound
+	case codes.AlreadyExists:
+		return http.StatusConflict
+	case codes.PermissionDenied:
+		return http.StatusForbidden
+	case codes.Unauthenticated:
+		return http.StatusUnauthorized
+	case codes.ResourceExhausted:
+		return http.StatusTooManyRequests
+	case codes.FailedPrecondition:
+		// Note, this deliberately doesn't translate to the similarly named '412 Precondition Failed' HTTP response status.
+		return http.StatusBadRequest
+	case codes.Aborted:
+		return http.StatusConflict
+	case codes.OutOfRange:
+		return http.StatusBadRequest
+	case codes.Unimplemented:
+		return http.StatusNotImplemented
+	case codes.Internal:
+		return http.StatusInternalServerError
+	case codes.Unavailable:
+		return http.StatusServiceUnavailable
+	case codes.DataLoss:
+		return http.StatusInternalServerError
+	}
+
+	grpclog.Infof("Unknown gRPC error code: %v", code)
+	return http.StatusInternalServerError
+}
+
+var (
+	// HTTPError replies to the request with the error.
+	// You can set a custom function to this variable to customize error format.
+	HTTPError = DefaultHTTPError
+	// OtherErrorHandler handles the following error used by the gateway: StatusMethodNotAllowed StatusNotFound and StatusBadRequest
+	OtherErrorHandler = DefaultOtherErrorHandler
+)
+
+type errorBody struct {
+	Error string `protobuf:"bytes,1,name=error" json:"error"`
+	// This is to make the error more compatible with users that expect errors to be Status objects:
+	// https://github.com/grpc/grpc/blob/master/src/proto/grpc/status/status.proto
+	// It should be the exact same message as the Error field.
+	Message string     `protobuf:"bytes,1,name=message" json:"message"`
+	Code    int32      `protobuf:"varint,2,name=code" json:"code"`
+	Details []*any.Any `protobuf:"bytes,3,rep,name=details" json:"details,omitempty"`
+}
+
+// Make this also conform to proto.Message for builtin JSONPb Marshaler
+func (e *errorBody) Reset()         { *e = errorBody{} }
+func (e *errorBody) String() string { return proto.CompactTextString(e) }
+func (*errorBody) ProtoMessage()    {}
+
+// DefaultHTTPError is the default implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a JSON object,
+// which contains a member whose key is "error" and whose value is err.Error().
+func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	const fallback = `{"error": "failed to marshal error message"}`
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	w.Header().Del("Trailer")
+
+	contentType := marshaler.ContentType()
+	// Check marshaler on run time in order to keep backwards compatability
+	// An interface param needs to be added to the ContentType() function on
+	// the Marshal interface to be able to remove this check
+	if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
+		pb := s.Proto()
+		contentType = httpBodyMarshaler.ContentTypeFromMessage(pb)
+	}
+	w.Header().Set("Content-Type", contentType)
+
+	body := &errorBody{
+		Error:   s.Message(),
+		Message: s.Message(),
+		Code:    int32(s.Code()),
+		Details: s.Proto().GetDetails(),
+	}
+
+	buf, merr := marshaler.Marshal(body)
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", body, merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+// DefaultOtherErrorHandler is the default implementation of OtherErrorHandler.
+// It simply writes a string representation of the given error into "w".
+func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, msg string, code int) {
+	http.Error(w, msg, code)
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/fieldmask.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/fieldmask.go
new file mode 100644
index 0000000..e1cf7a9
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/fieldmask.go
@@ -0,0 +1,70 @@
+package runtime
+
+import (
+	"encoding/json"
+	"io"
+	"strings"
+
+	"github.com/golang/protobuf/protoc-gen-go/generator"
+	"google.golang.org/genproto/protobuf/field_mask"
+)
+
+// FieldMaskFromRequestBody creates a FieldMask printing all complete paths from the JSON body.
+func FieldMaskFromRequestBody(r io.Reader) (*field_mask.FieldMask, error) {
+	fm := &field_mask.FieldMask{}
+	var root interface{}
+	if err := json.NewDecoder(r).Decode(&root); err != nil {
+		if err == io.EOF {
+			return fm, nil
+		}
+		return nil, err
+	}
+
+	queue := []fieldMaskPathItem{{node: root}}
+	for len(queue) > 0 {
+		// dequeue an item
+		item := queue[0]
+		queue = queue[1:]
+
+		if m, ok := item.node.(map[string]interface{}); ok {
+			// if the item is an object, then enqueue all of its children
+			for k, v := range m {
+				queue = append(queue, fieldMaskPathItem{path: append(item.path, generator.CamelCase(k)), node: v})
+			}
+		} else if len(item.path) > 0 {
+			// otherwise, it's a leaf node so print its path
+			fm.Paths = append(fm.Paths, strings.Join(item.path, "."))
+		}
+	}
+
+	return fm, nil
+}
+
+// fieldMaskPathItem stores a in-progress deconstruction of a path for a fieldmask
+type fieldMaskPathItem struct {
+	// the list of prior fields leading up to node
+	path []string
+
+	// a generic decoded json object the current item to inspect for further path extraction
+	node interface{}
+}
+
+// CamelCaseFieldMask updates the given FieldMask by converting all of its paths to CamelCase, using the same heuristic
+// that's used for naming protobuf fields in Go.
+func CamelCaseFieldMask(mask *field_mask.FieldMask) {
+	if mask == nil || mask.Paths == nil {
+		return
+	}
+
+	var newPaths []string
+	for _, path := range mask.Paths {
+		lowerCasedParts := strings.Split(path, ".")
+		var camelCasedParts []string
+		for _, part := range lowerCasedParts {
+			camelCasedParts = append(camelCasedParts, generator.CamelCase(part))
+		}
+		newPaths = append(newPaths, strings.Join(camelCasedParts, "."))
+	}
+
+	mask.Paths = newPaths
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go
new file mode 100644
index 0000000..2af9006
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/handler.go
@@ -0,0 +1,209 @@
+package runtime
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/textproto"
+
+	"context"
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/internal"
+	"google.golang.org/grpc/grpclog"
+)
+
+var errEmptyResponse = errors.New("empty response")
+
+// ForwardResponseStream forwards the stream from gRPC server to REST client.
+func ForwardResponseStream(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, recv func() (proto.Message, error), opts ...func(context.Context, http.ResponseWriter, proto.Message) error) {
+	f, ok := w.(http.Flusher)
+	if !ok {
+		grpclog.Infof("Flush not supported in %T", w)
+		http.Error(w, "unexpected type of web server", http.StatusInternalServerError)
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+		http.Error(w, "unexpected error", http.StatusInternalServerError)
+		return
+	}
+	handleForwardResponseServerMetadata(w, mux, md)
+
+	w.Header().Set("Transfer-Encoding", "chunked")
+	w.Header().Set("Content-Type", marshaler.ContentType())
+	if err := handleForwardResponseOptions(ctx, w, nil, opts); err != nil {
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+
+	var delimiter []byte
+	if d, ok := marshaler.(Delimited); ok {
+		delimiter = d.Delimiter()
+	} else {
+		delimiter = []byte("\n")
+	}
+
+	var wroteHeader bool
+	for {
+		resp, err := recv()
+		if err == io.EOF {
+			return
+		}
+		if err != nil {
+			handleForwardResponseStreamError(ctx, wroteHeader, marshaler, w, req, mux, err)
+			return
+		}
+		if err := handleForwardResponseOptions(ctx, w, resp, opts); err != nil {
+			handleForwardResponseStreamError(ctx, wroteHeader, marshaler, w, req, mux, err)
+			return
+		}
+
+		buf, err := marshaler.Marshal(streamChunk(ctx, resp, mux.streamErrorHandler))
+		if err != nil {
+			grpclog.Infof("Failed to marshal response chunk: %v", err)
+			handleForwardResponseStreamError(ctx, wroteHeader, marshaler, w, req, mux, err)
+			return
+		}
+		if _, err = w.Write(buf); err != nil {
+			grpclog.Infof("Failed to send response chunk: %v", err)
+			return
+		}
+		wroteHeader = true
+		if _, err = w.Write(delimiter); err != nil {
+			grpclog.Infof("Failed to send delimiter chunk: %v", err)
+			return
+		}
+		f.Flush()
+	}
+}
+
+func handleForwardResponseServerMetadata(w http.ResponseWriter, mux *ServeMux, md ServerMetadata) {
+	for k, vs := range md.HeaderMD {
+		if h, ok := mux.outgoingHeaderMatcher(k); ok {
+			for _, v := range vs {
+				w.Header().Add(h, v)
+			}
+		}
+	}
+}
+
+func handleForwardResponseTrailerHeader(w http.ResponseWriter, md ServerMetadata) {
+	for k := range md.TrailerMD {
+		tKey := textproto.CanonicalMIMEHeaderKey(fmt.Sprintf("%s%s", MetadataTrailerPrefix, k))
+		w.Header().Add("Trailer", tKey)
+	}
+}
+
+func handleForwardResponseTrailer(w http.ResponseWriter, md ServerMetadata) {
+	for k, vs := range md.TrailerMD {
+		tKey := fmt.Sprintf("%s%s", MetadataTrailerPrefix, k)
+		for _, v := range vs {
+			w.Header().Add(tKey, v)
+		}
+	}
+}
+
+// responseBody interface contains method for getting field for marshaling to the response body
+// this method is generated for response struct from the value of `response_body` in the `google.api.HttpRule`
+type responseBody interface {
+	XXX_ResponseBody() interface{}
+}
+
+// ForwardResponseMessage forwards the message "resp" from gRPC server to REST client.
+func ForwardResponseMessage(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, req *http.Request, resp proto.Message, opts ...func(context.Context, http.ResponseWriter, proto.Message) error) {
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+
+	contentType := marshaler.ContentType()
+	// Check marshaler on run time in order to keep backwards compatability
+	// An interface param needs to be added to the ContentType() function on
+	// the Marshal interface to be able to remove this check
+	if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
+		contentType = httpBodyMarshaler.ContentTypeFromMessage(resp)
+	}
+	w.Header().Set("Content-Type", contentType)
+
+	if err := handleForwardResponseOptions(ctx, w, resp, opts); err != nil {
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+	var buf []byte
+	var err error
+	if rb, ok := resp.(responseBody); ok {
+		buf, err = marshaler.Marshal(rb.XXX_ResponseBody())
+	} else {
+		buf, err = marshaler.Marshal(resp)
+	}
+	if err != nil {
+		grpclog.Infof("Marshal error: %v", err)
+		HTTPError(ctx, mux, marshaler, w, req, err)
+		return
+	}
+
+	if _, err = w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+func handleForwardResponseOptions(ctx context.Context, w http.ResponseWriter, resp proto.Message, opts []func(context.Context, http.ResponseWriter, proto.Message) error) error {
+	if len(opts) == 0 {
+		return nil
+	}
+	for _, opt := range opts {
+		if err := opt(ctx, w, resp); err != nil {
+			grpclog.Infof("Error handling ForwardResponseOptions: %v", err)
+			return err
+		}
+	}
+	return nil
+}
+
+func handleForwardResponseStreamError(ctx context.Context, wroteHeader bool, marshaler Marshaler, w http.ResponseWriter, req *http.Request, mux *ServeMux, err error) {
+	serr := streamError(ctx, mux.streamErrorHandler, err)
+	if !wroteHeader {
+		w.WriteHeader(int(serr.HttpCode))
+	}
+	buf, merr := marshaler.Marshal(errorChunk(serr))
+	if merr != nil {
+		grpclog.Infof("Failed to marshal an error: %v", merr)
+		return
+	}
+	if _, werr := w.Write(buf); werr != nil {
+		grpclog.Infof("Failed to notify error to client: %v", werr)
+		return
+	}
+}
+
+// streamChunk returns a chunk in a response stream for the given result. The
+// given errHandler is used to render an error chunk if result is nil.
+func streamChunk(ctx context.Context, result proto.Message, errHandler StreamErrorHandlerFunc) map[string]proto.Message {
+	if result == nil {
+		return errorChunk(streamError(ctx, errHandler, errEmptyResponse))
+	}
+	return map[string]proto.Message{"result": result}
+}
+
+// streamError returns the payload for the final message in a response stream
+// that represents the given err.
+func streamError(ctx context.Context, errHandler StreamErrorHandlerFunc, err error) *StreamError {
+	serr := errHandler(ctx, err)
+	if serr != nil {
+		return serr
+	}
+	// TODO: log about misbehaving stream error handler?
+	return DefaultHTTPStreamErrorHandler(ctx, err)
+}
+
+func errorChunk(err *StreamError) map[string]proto.Message {
+	return map[string]proto.Message{"error": (*internal.StreamError)(err)}
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_httpbodyproto.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_httpbodyproto.go
new file mode 100644
index 0000000..f55285b
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_httpbodyproto.go
@@ -0,0 +1,43 @@
+package runtime
+
+import (
+	"google.golang.org/genproto/googleapis/api/httpbody"
+)
+
+// SetHTTPBodyMarshaler overwrite the default marshaler with the HTTPBodyMarshaler
+func SetHTTPBodyMarshaler(serveMux *ServeMux) {
+	serveMux.marshalers.mimeMap[MIMEWildcard] = &HTTPBodyMarshaler{
+		Marshaler: &JSONPb{OrigName: true},
+	}
+}
+
+// HTTPBodyMarshaler is a Marshaler which supports marshaling of a
+// google.api.HttpBody message as the full response body if it is
+// the actual message used as the response. If not, then this will
+// simply fallback to the Marshaler specified as its default Marshaler.
+type HTTPBodyMarshaler struct {
+	Marshaler
+}
+
+// ContentType implementation to keep backwards compatability with marshal interface
+func (h *HTTPBodyMarshaler) ContentType() string {
+	return h.ContentTypeFromMessage(nil)
+}
+
+// ContentTypeFromMessage in case v is a google.api.HttpBody message it returns
+// its specified content type otherwise fall back to the default Marshaler.
+func (h *HTTPBodyMarshaler) ContentTypeFromMessage(v interface{}) string {
+	if httpBody, ok := v.(*httpbody.HttpBody); ok {
+		return httpBody.GetContentType()
+	}
+	return h.Marshaler.ContentType()
+}
+
+// Marshal marshals "v" by returning the body bytes if v is a
+// google.api.HttpBody message, otherwise it falls back to the default Marshaler.
+func (h *HTTPBodyMarshaler) Marshal(v interface{}) ([]byte, error) {
+	if httpBody, ok := v.(*httpbody.HttpBody); ok {
+		return httpBody.Data, nil
+	}
+	return h.Marshaler.Marshal(v)
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go
new file mode 100644
index 0000000..f9d3a58
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_json.go
@@ -0,0 +1,45 @@
+package runtime
+
+import (
+	"encoding/json"
+	"io"
+)
+
+// JSONBuiltin is a Marshaler which marshals/unmarshals into/from JSON
+// with the standard "encoding/json" package of Golang.
+// Although it is generally faster for simple proto messages than JSONPb,
+// it does not support advanced features of protobuf, e.g. map, oneof, ....
+//
+// The NewEncoder and NewDecoder types return *json.Encoder and
+// *json.Decoder respectively.
+type JSONBuiltin struct{}
+
+// ContentType always Returns "application/json".
+func (*JSONBuiltin) ContentType() string {
+	return "application/json"
+}
+
+// Marshal marshals "v" into JSON
+func (j *JSONBuiltin) Marshal(v interface{}) ([]byte, error) {
+	return json.Marshal(v)
+}
+
+// Unmarshal unmarshals JSON data into "v".
+func (j *JSONBuiltin) Unmarshal(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}
+
+// NewDecoder returns a Decoder which reads JSON stream from "r".
+func (j *JSONBuiltin) NewDecoder(r io.Reader) Decoder {
+	return json.NewDecoder(r)
+}
+
+// NewEncoder returns an Encoder which writes JSON stream into "w".
+func (j *JSONBuiltin) NewEncoder(w io.Writer) Encoder {
+	return json.NewEncoder(w)
+}
+
+// Delimiter for newline encoded JSON streams.
+func (j *JSONBuiltin) Delimiter() []byte {
+	return []byte("\n")
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go
new file mode 100644
index 0000000..f0de351
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_jsonpb.go
@@ -0,0 +1,262 @@
+package runtime
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"reflect"
+
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/proto"
+)
+
+// JSONPb is a Marshaler which marshals/unmarshals into/from JSON
+// with the "github.com/golang/protobuf/jsonpb".
+// It supports fully functionality of protobuf unlike JSONBuiltin.
+//
+// The NewDecoder method returns a DecoderWrapper, so the underlying
+// *json.Decoder methods can be used.
+type JSONPb jsonpb.Marshaler
+
+// ContentType always returns "application/json".
+func (*JSONPb) ContentType() string {
+	return "application/json"
+}
+
+// Marshal marshals "v" into JSON.
+func (j *JSONPb) Marshal(v interface{}) ([]byte, error) {
+	if _, ok := v.(proto.Message); !ok {
+		return j.marshalNonProtoField(v)
+	}
+
+	var buf bytes.Buffer
+	if err := j.marshalTo(&buf, v); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func (j *JSONPb) marshalTo(w io.Writer, v interface{}) error {
+	p, ok := v.(proto.Message)
+	if !ok {
+		buf, err := j.marshalNonProtoField(v)
+		if err != nil {
+			return err
+		}
+		_, err = w.Write(buf)
+		return err
+	}
+	return (*jsonpb.Marshaler)(j).Marshal(w, p)
+}
+
+var (
+	// protoMessageType is stored to prevent constant lookup of the same type at runtime.
+	protoMessageType = reflect.TypeOf((*proto.Message)(nil)).Elem()
+)
+
+// marshalNonProto marshals a non-message field of a protobuf message.
+// This function does not correctly marshals arbitrary data structure into JSON,
+// but it is only capable of marshaling non-message field values of protobuf,
+// i.e. primitive types, enums; pointers to primitives or enums; maps from
+// integer/string types to primitives/enums/pointers to messages.
+func (j *JSONPb) marshalNonProtoField(v interface{}) ([]byte, error) {
+	if v == nil {
+		return []byte("null"), nil
+	}
+	rv := reflect.ValueOf(v)
+	for rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			return []byte("null"), nil
+		}
+		rv = rv.Elem()
+	}
+
+	if rv.Kind() == reflect.Slice {
+		if rv.IsNil() {
+			if j.EmitDefaults {
+				return []byte("[]"), nil
+			}
+			return []byte("null"), nil
+		}
+
+		if rv.Type().Elem().Implements(protoMessageType) {
+			var buf bytes.Buffer
+			err := buf.WriteByte('[')
+			if err != nil {
+				return nil, err
+			}
+			for i := 0; i < rv.Len(); i++ {
+				if i != 0 {
+					err = buf.WriteByte(',')
+					if err != nil {
+						return nil, err
+					}
+				}
+				if err = (*jsonpb.Marshaler)(j).Marshal(&buf, rv.Index(i).Interface().(proto.Message)); err != nil {
+					return nil, err
+				}
+			}
+			err = buf.WriteByte(']')
+			if err != nil {
+				return nil, err
+			}
+
+			return buf.Bytes(), nil
+		}
+	}
+
+	if rv.Kind() == reflect.Map {
+		m := make(map[string]*json.RawMessage)
+		for _, k := range rv.MapKeys() {
+			buf, err := j.Marshal(rv.MapIndex(k).Interface())
+			if err != nil {
+				return nil, err
+			}
+			m[fmt.Sprintf("%v", k.Interface())] = (*json.RawMessage)(&buf)
+		}
+		if j.Indent != "" {
+			return json.MarshalIndent(m, "", j.Indent)
+		}
+		return json.Marshal(m)
+	}
+	if enum, ok := rv.Interface().(protoEnum); ok && !j.EnumsAsInts {
+		return json.Marshal(enum.String())
+	}
+	return json.Marshal(rv.Interface())
+}
+
+// Unmarshal unmarshals JSON "data" into "v"
+func (j *JSONPb) Unmarshal(data []byte, v interface{}) error {
+	return unmarshalJSONPb(data, v)
+}
+
+// NewDecoder returns a Decoder which reads JSON stream from "r".
+func (j *JSONPb) NewDecoder(r io.Reader) Decoder {
+	d := json.NewDecoder(r)
+	return DecoderWrapper{Decoder: d}
+}
+
+// DecoderWrapper is a wrapper around a *json.Decoder that adds
+// support for protos to the Decode method.
+type DecoderWrapper struct {
+	*json.Decoder
+}
+
+// Decode wraps the embedded decoder's Decode method to support
+// protos using a jsonpb.Unmarshaler.
+func (d DecoderWrapper) Decode(v interface{}) error {
+	return decodeJSONPb(d.Decoder, v)
+}
+
+// NewEncoder returns an Encoder which writes JSON stream into "w".
+func (j *JSONPb) NewEncoder(w io.Writer) Encoder {
+	return EncoderFunc(func(v interface{}) error {
+		if err := j.marshalTo(w, v); err != nil {
+			return err
+		}
+		// mimic json.Encoder by adding a newline (makes output
+		// easier to read when it contains multiple encoded items)
+		_, err := w.Write(j.Delimiter())
+		return err
+	})
+}
+
+func unmarshalJSONPb(data []byte, v interface{}) error {
+	d := json.NewDecoder(bytes.NewReader(data))
+	return decodeJSONPb(d, v)
+}
+
+func decodeJSONPb(d *json.Decoder, v interface{}) error {
+	p, ok := v.(proto.Message)
+	if !ok {
+		return decodeNonProtoField(d, v)
+	}
+	unmarshaler := &jsonpb.Unmarshaler{AllowUnknownFields: allowUnknownFields}
+	return unmarshaler.UnmarshalNext(d, p)
+}
+
+func decodeNonProtoField(d *json.Decoder, v interface{}) error {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr {
+		return fmt.Errorf("%T is not a pointer", v)
+	}
+	for rv.Kind() == reflect.Ptr {
+		if rv.IsNil() {
+			rv.Set(reflect.New(rv.Type().Elem()))
+		}
+		if rv.Type().ConvertibleTo(typeProtoMessage) {
+			unmarshaler := &jsonpb.Unmarshaler{AllowUnknownFields: allowUnknownFields}
+			return unmarshaler.UnmarshalNext(d, rv.Interface().(proto.Message))
+		}
+		rv = rv.Elem()
+	}
+	if rv.Kind() == reflect.Map {
+		if rv.IsNil() {
+			rv.Set(reflect.MakeMap(rv.Type()))
+		}
+		conv, ok := convFromType[rv.Type().Key().Kind()]
+		if !ok {
+			return fmt.Errorf("unsupported type of map field key: %v", rv.Type().Key())
+		}
+
+		m := make(map[string]*json.RawMessage)
+		if err := d.Decode(&m); err != nil {
+			return err
+		}
+		for k, v := range m {
+			result := conv.Call([]reflect.Value{reflect.ValueOf(k)})
+			if err := result[1].Interface(); err != nil {
+				return err.(error)
+			}
+			bk := result[0]
+			bv := reflect.New(rv.Type().Elem())
+			if err := unmarshalJSONPb([]byte(*v), bv.Interface()); err != nil {
+				return err
+			}
+			rv.SetMapIndex(bk, bv.Elem())
+		}
+		return nil
+	}
+	if _, ok := rv.Interface().(protoEnum); ok {
+		var repr interface{}
+		if err := d.Decode(&repr); err != nil {
+			return err
+		}
+		switch repr.(type) {
+		case string:
+			// TODO(yugui) Should use proto.StructProperties?
+			return fmt.Errorf("unmarshaling of symbolic enum %q not supported: %T", repr, rv.Interface())
+		case float64:
+			rv.Set(reflect.ValueOf(int32(repr.(float64))).Convert(rv.Type()))
+			return nil
+		default:
+			return fmt.Errorf("cannot assign %#v into Go type %T", repr, rv.Interface())
+		}
+	}
+	return d.Decode(v)
+}
+
+type protoEnum interface {
+	fmt.Stringer
+	EnumDescriptor() ([]byte, []int)
+}
+
+var typeProtoMessage = reflect.TypeOf((*proto.Message)(nil)).Elem()
+
+// Delimiter for newline encoded JSON streams.
+func (j *JSONPb) Delimiter() []byte {
+	return []byte("\n")
+}
+
+// allowUnknownFields helps not to return an error when the destination
+// is a struct and the input contains object keys which do not match any
+// non-ignored, exported fields in the destination.
+var allowUnknownFields = true
+
+// DisallowUnknownFields enables option in decoder (unmarshaller) to
+// return an error when it finds an unknown field. This function must be
+// called before using the JSON marshaller.
+func DisallowUnknownFields() {
+	allowUnknownFields = false
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go
new file mode 100644
index 0000000..f65d1a2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshal_proto.go
@@ -0,0 +1,62 @@
+package runtime
+
+import (
+	"io"
+
+	"errors"
+	"github.com/golang/protobuf/proto"
+	"io/ioutil"
+)
+
+// ProtoMarshaller is a Marshaller which marshals/unmarshals into/from serialize proto bytes
+type ProtoMarshaller struct{}
+
+// ContentType always returns "application/octet-stream".
+func (*ProtoMarshaller) ContentType() string {
+	return "application/octet-stream"
+}
+
+// Marshal marshals "value" into Proto
+func (*ProtoMarshaller) Marshal(value interface{}) ([]byte, error) {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return nil, errors.New("unable to marshal non proto field")
+	}
+	return proto.Marshal(message)
+}
+
+// Unmarshal unmarshals proto "data" into "value"
+func (*ProtoMarshaller) Unmarshal(data []byte, value interface{}) error {
+	message, ok := value.(proto.Message)
+	if !ok {
+		return errors.New("unable to unmarshal non proto field")
+	}
+	return proto.Unmarshal(data, message)
+}
+
+// NewDecoder returns a Decoder which reads proto stream from "reader".
+func (marshaller *ProtoMarshaller) NewDecoder(reader io.Reader) Decoder {
+	return DecoderFunc(func(value interface{}) error {
+		buffer, err := ioutil.ReadAll(reader)
+		if err != nil {
+			return err
+		}
+		return marshaller.Unmarshal(buffer, value)
+	})
+}
+
+// NewEncoder returns an Encoder which writes proto stream into "writer".
+func (marshaller *ProtoMarshaller) NewEncoder(writer io.Writer) Encoder {
+	return EncoderFunc(func(value interface{}) error {
+		buffer, err := marshaller.Marshal(value)
+		if err != nil {
+			return err
+		}
+		_, err = writer.Write(buffer)
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go
new file mode 100644
index 0000000..98fe6e8
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler.go
@@ -0,0 +1,48 @@
+package runtime
+
+import (
+	"io"
+)
+
+// Marshaler defines a conversion between byte sequence and gRPC payloads / fields.
+type Marshaler interface {
+	// Marshal marshals "v" into byte sequence.
+	Marshal(v interface{}) ([]byte, error)
+	// Unmarshal unmarshals "data" into "v".
+	// "v" must be a pointer value.
+	Unmarshal(data []byte, v interface{}) error
+	// NewDecoder returns a Decoder which reads byte sequence from "r".
+	NewDecoder(r io.Reader) Decoder
+	// NewEncoder returns an Encoder which writes bytes sequence into "w".
+	NewEncoder(w io.Writer) Encoder
+	// ContentType returns the Content-Type which this marshaler is responsible for.
+	ContentType() string
+}
+
+// Decoder decodes a byte sequence
+type Decoder interface {
+	Decode(v interface{}) error
+}
+
+// Encoder encodes gRPC payloads / fields into byte sequence.
+type Encoder interface {
+	Encode(v interface{}) error
+}
+
+// DecoderFunc adapts an decoder function into Decoder.
+type DecoderFunc func(v interface{}) error
+
+// Decode delegates invocations to the underlying function itself.
+func (f DecoderFunc) Decode(v interface{}) error { return f(v) }
+
+// EncoderFunc adapts an encoder function into Encoder
+type EncoderFunc func(v interface{}) error
+
+// Encode delegates invocations to the underlying function itself.
+func (f EncoderFunc) Encode(v interface{}) error { return f(v) }
+
+// Delimited defines the streaming delimiter.
+type Delimited interface {
+	// Delimiter returns the record seperator for the stream.
+	Delimiter() []byte
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go
new file mode 100644
index 0000000..5cc53ae
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/marshaler_registry.go
@@ -0,0 +1,91 @@
+package runtime
+
+import (
+	"errors"
+	"net/http"
+)
+
+// MIMEWildcard is the fallback MIME type used for requests which do not match
+// a registered MIME type.
+const MIMEWildcard = "*"
+
+var (
+	acceptHeader      = http.CanonicalHeaderKey("Accept")
+	contentTypeHeader = http.CanonicalHeaderKey("Content-Type")
+
+	defaultMarshaler = &JSONPb{OrigName: true}
+)
+
+// MarshalerForRequest returns the inbound/outbound marshalers for this request.
+// It checks the registry on the ServeMux for the MIME type set by the Content-Type header.
+// If it isn't set (or the request Content-Type is empty), checks for "*".
+// If there are multiple Content-Type headers set, choose the first one that it can
+// exactly match in the registry.
+// Otherwise, it follows the above logic for "*"/InboundMarshaler/OutboundMarshaler.
+func MarshalerForRequest(mux *ServeMux, r *http.Request) (inbound Marshaler, outbound Marshaler) {
+	for _, acceptVal := range r.Header[acceptHeader] {
+		if m, ok := mux.marshalers.mimeMap[acceptVal]; ok {
+			outbound = m
+			break
+		}
+	}
+
+	for _, contentTypeVal := range r.Header[contentTypeHeader] {
+		if m, ok := mux.marshalers.mimeMap[contentTypeVal]; ok {
+			inbound = m
+			break
+		}
+	}
+
+	if inbound == nil {
+		inbound = mux.marshalers.mimeMap[MIMEWildcard]
+	}
+	if outbound == nil {
+		outbound = inbound
+	}
+
+	return inbound, outbound
+}
+
+// marshalerRegistry is a mapping from MIME types to Marshalers.
+type marshalerRegistry struct {
+	mimeMap map[string]Marshaler
+}
+
+// add adds a marshaler for a case-sensitive MIME type string ("*" to match any
+// MIME type).
+func (m marshalerRegistry) add(mime string, marshaler Marshaler) error {
+	if len(mime) == 0 {
+		return errors.New("empty MIME type")
+	}
+
+	m.mimeMap[mime] = marshaler
+
+	return nil
+}
+
+// makeMarshalerMIMERegistry returns a new registry of marshalers.
+// It allows for a mapping of case-sensitive Content-Type MIME type string to runtime.Marshaler interfaces.
+//
+// For example, you could allow the client to specify the use of the runtime.JSONPb marshaler
+// with a "application/jsonpb" Content-Type and the use of the runtime.JSONBuiltin marshaler
+// with a "application/json" Content-Type.
+// "*" can be used to match any Content-Type.
+// This can be attached to a ServerMux with the marshaler option.
+func makeMarshalerMIMERegistry() marshalerRegistry {
+	return marshalerRegistry{
+		mimeMap: map[string]Marshaler{
+			MIMEWildcard: defaultMarshaler,
+		},
+	}
+}
+
+// WithMarshalerOption returns a ServeMuxOption which associates inbound and outbound
+// Marshalers to a MIME type in mux.
+func WithMarshalerOption(mime string, marshaler Marshaler) ServeMuxOption {
+	return func(mux *ServeMux) {
+		if err := mux.marshalers.add(mime, marshaler); err != nil {
+			panic(err)
+		}
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go
new file mode 100644
index 0000000..1da3a58
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/mux.go
@@ -0,0 +1,303 @@
+package runtime
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/textproto"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// A HandlerFunc handles a specific pair of path pattern and HTTP method.
+type HandlerFunc func(w http.ResponseWriter, r *http.Request, pathParams map[string]string)
+
+// ErrUnknownURI is the error supplied to a custom ProtoErrorHandlerFunc when
+// a request is received with a URI path that does not match any registered
+// service method.
+//
+// Since gRPC servers return an "Unimplemented" code for requests with an
+// unrecognized URI path, this error also has a gRPC "Unimplemented" code.
+var ErrUnknownURI = status.Error(codes.Unimplemented, http.StatusText(http.StatusNotImplemented))
+
+// ServeMux is a request multiplexer for grpc-gateway.
+// It matches http requests to patterns and invokes the corresponding handler.
+type ServeMux struct {
+	// handlers maps HTTP method to a list of handlers.
+	handlers                  map[string][]handler
+	forwardResponseOptions    []func(context.Context, http.ResponseWriter, proto.Message) error
+	marshalers                marshalerRegistry
+	incomingHeaderMatcher     HeaderMatcherFunc
+	outgoingHeaderMatcher     HeaderMatcherFunc
+	metadataAnnotators        []func(context.Context, *http.Request) metadata.MD
+	streamErrorHandler        StreamErrorHandlerFunc
+	protoErrorHandler         ProtoErrorHandlerFunc
+	disablePathLengthFallback bool
+	lastMatchWins             bool
+}
+
+// ServeMuxOption is an option that can be given to a ServeMux on construction.
+type ServeMuxOption func(*ServeMux)
+
+// WithForwardResponseOption returns a ServeMuxOption representing the forwardResponseOption.
+//
+// forwardResponseOption is an option that will be called on the relevant context.Context,
+// http.ResponseWriter, and proto.Message before every forwarded response.
+//
+// The message may be nil in the case where just a header is being sent.
+func WithForwardResponseOption(forwardResponseOption func(context.Context, http.ResponseWriter, proto.Message) error) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.forwardResponseOptions = append(serveMux.forwardResponseOptions, forwardResponseOption)
+	}
+}
+
+// HeaderMatcherFunc checks whether a header key should be forwarded to/from gRPC context.
+type HeaderMatcherFunc func(string) (string, bool)
+
+// DefaultHeaderMatcher is used to pass http request headers to/from gRPC context. This adds permanent HTTP header
+// keys (as specified by the IANA) to gRPC context with grpcgateway- prefix. HTTP headers that start with
+// 'Grpc-Metadata-' are mapped to gRPC metadata after removing prefix 'Grpc-Metadata-'.
+func DefaultHeaderMatcher(key string) (string, bool) {
+	key = textproto.CanonicalMIMEHeaderKey(key)
+	if isPermanentHTTPHeader(key) {
+		return MetadataPrefix + key, true
+	} else if strings.HasPrefix(key, MetadataHeaderPrefix) {
+		return key[len(MetadataHeaderPrefix):], true
+	}
+	return "", false
+}
+
+// WithIncomingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for incoming request to gateway.
+//
+// This matcher will be called with each header in http.Request. If matcher returns true, that header will be
+// passed to gRPC context. To transform the header before passing to gRPC context, matcher should return modified header.
+func WithIncomingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption {
+	return func(mux *ServeMux) {
+		mux.incomingHeaderMatcher = fn
+	}
+}
+
+// WithOutgoingHeaderMatcher returns a ServeMuxOption representing a headerMatcher for outgoing response from gateway.
+//
+// This matcher will be called with each header in response header metadata. If matcher returns true, that header will be
+// passed to http response returned from gateway. To transform the header before passing to response,
+// matcher should return modified header.
+func WithOutgoingHeaderMatcher(fn HeaderMatcherFunc) ServeMuxOption {
+	return func(mux *ServeMux) {
+		mux.outgoingHeaderMatcher = fn
+	}
+}
+
+// WithMetadata returns a ServeMuxOption for passing metadata to a gRPC context.
+//
+// This can be used by services that need to read from http.Request and modify gRPC context. A common use case
+// is reading token from cookie and adding it in gRPC context.
+func WithMetadata(annotator func(context.Context, *http.Request) metadata.MD) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.metadataAnnotators = append(serveMux.metadataAnnotators, annotator)
+	}
+}
+
+// WithProtoErrorHandler returns a ServeMuxOption for passing metadata to a gRPC context.
+//
+// This can be used to handle an error as general proto message defined by gRPC.
+// The response including body and status is not backward compatible with the default error handler.
+// When this option is used, HTTPError and OtherErrorHandler are overwritten on initialization.
+func WithProtoErrorHandler(fn ProtoErrorHandlerFunc) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.protoErrorHandler = fn
+	}
+}
+
+// WithDisablePathLengthFallback returns a ServeMuxOption for disable path length fallback.
+func WithDisablePathLengthFallback() ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.disablePathLengthFallback = true
+	}
+}
+
+// WithStreamErrorHandler returns a ServeMuxOption that will use the given custom stream
+// error handler, which allows for customizing the error trailer for server-streaming
+// calls.
+//
+// For stream errors that occur before any response has been written, the mux's
+// ProtoErrorHandler will be invoked. However, once data has been written, the errors must
+// be handled differently: they must be included in the response body. The response body's
+// final message will include the error details returned by the stream error handler.
+func WithStreamErrorHandler(fn StreamErrorHandlerFunc) ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.streamErrorHandler = fn
+	}
+}
+
+// WithLastMatchWins returns a ServeMuxOption that will enable "last
+// match wins" behavior, where if multiple path patterns match a
+// request path, the last one defined in the .proto file will be used.
+func WithLastMatchWins() ServeMuxOption {
+	return func(serveMux *ServeMux) {
+		serveMux.lastMatchWins = true
+	}
+}
+
+// NewServeMux returns a new ServeMux whose internal mapping is empty.
+func NewServeMux(opts ...ServeMuxOption) *ServeMux {
+	serveMux := &ServeMux{
+		handlers:               make(map[string][]handler),
+		forwardResponseOptions: make([]func(context.Context, http.ResponseWriter, proto.Message) error, 0),
+		marshalers:             makeMarshalerMIMERegistry(),
+		streamErrorHandler:     DefaultHTTPStreamErrorHandler,
+	}
+
+	for _, opt := range opts {
+		opt(serveMux)
+	}
+
+	if serveMux.protoErrorHandler != nil {
+		HTTPError = serveMux.protoErrorHandler
+		// OtherErrorHandler is no longer used when protoErrorHandler is set.
+		// Overwritten by a special error handler to return Unknown.
+		OtherErrorHandler = func(w http.ResponseWriter, r *http.Request, _ string, _ int) {
+			ctx := context.Background()
+			_, outboundMarshaler := MarshalerForRequest(serveMux, r)
+			sterr := status.Error(codes.Unknown, "unexpected use of OtherErrorHandler")
+			serveMux.protoErrorHandler(ctx, serveMux, outboundMarshaler, w, r, sterr)
+		}
+	}
+
+	if serveMux.incomingHeaderMatcher == nil {
+		serveMux.incomingHeaderMatcher = DefaultHeaderMatcher
+	}
+
+	if serveMux.outgoingHeaderMatcher == nil {
+		serveMux.outgoingHeaderMatcher = func(key string) (string, bool) {
+			return fmt.Sprintf("%s%s", MetadataHeaderPrefix, key), true
+		}
+	}
+
+	return serveMux
+}
+
+// Handle associates "h" to the pair of HTTP method and path pattern.
+func (s *ServeMux) Handle(meth string, pat Pattern, h HandlerFunc) {
+	if s.lastMatchWins {
+		s.handlers[meth] = append([]handler{handler{pat: pat, h: h}}, s.handlers[meth]...)
+	} else {
+		s.handlers[meth] = append(s.handlers[meth], handler{pat: pat, h: h})
+	}
+}
+
+// ServeHTTP dispatches the request to the first handler whose pattern matches to r.Method and r.Path.
+func (s *ServeMux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	path := r.URL.Path
+	if !strings.HasPrefix(path, "/") {
+		if s.protoErrorHandler != nil {
+			_, outboundMarshaler := MarshalerForRequest(s, r)
+			sterr := status.Error(codes.InvalidArgument, http.StatusText(http.StatusBadRequest))
+			s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+		} else {
+			OtherErrorHandler(w, r, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
+		}
+		return
+	}
+
+	components := strings.Split(path[1:], "/")
+	l := len(components)
+	var verb string
+	if idx := strings.LastIndex(components[l-1], ":"); idx == 0 {
+		if s.protoErrorHandler != nil {
+			_, outboundMarshaler := MarshalerForRequest(s, r)
+			s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, ErrUnknownURI)
+		} else {
+			OtherErrorHandler(w, r, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+		}
+		return
+	} else if idx > 0 {
+		c := components[l-1]
+		components[l-1], verb = c[:idx], c[idx+1:]
+	}
+
+	if override := r.Header.Get("X-HTTP-Method-Override"); override != "" && s.isPathLengthFallback(r) {
+		r.Method = strings.ToUpper(override)
+		if err := r.ParseForm(); err != nil {
+			if s.protoErrorHandler != nil {
+				_, outboundMarshaler := MarshalerForRequest(s, r)
+				sterr := status.Error(codes.InvalidArgument, err.Error())
+				s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+			} else {
+				OtherErrorHandler(w, r, err.Error(), http.StatusBadRequest)
+			}
+			return
+		}
+	}
+	for _, h := range s.handlers[r.Method] {
+		pathParams, err := h.pat.Match(components, verb)
+		if err != nil {
+			continue
+		}
+		h.h(w, r, pathParams)
+		return
+	}
+
+	// lookup other methods to handle fallback from GET to POST and
+	// to determine if it is MethodNotAllowed or NotFound.
+	for m, handlers := range s.handlers {
+		if m == r.Method {
+			continue
+		}
+		for _, h := range handlers {
+			pathParams, err := h.pat.Match(components, verb)
+			if err != nil {
+				continue
+			}
+			// X-HTTP-Method-Override is optional. Always allow fallback to POST.
+			if s.isPathLengthFallback(r) {
+				if err := r.ParseForm(); err != nil {
+					if s.protoErrorHandler != nil {
+						_, outboundMarshaler := MarshalerForRequest(s, r)
+						sterr := status.Error(codes.InvalidArgument, err.Error())
+						s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, sterr)
+					} else {
+						OtherErrorHandler(w, r, err.Error(), http.StatusBadRequest)
+					}
+					return
+				}
+				h.h(w, r, pathParams)
+				return
+			}
+			if s.protoErrorHandler != nil {
+				_, outboundMarshaler := MarshalerForRequest(s, r)
+				s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, ErrUnknownURI)
+			} else {
+				OtherErrorHandler(w, r, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
+			}
+			return
+		}
+	}
+
+	if s.protoErrorHandler != nil {
+		_, outboundMarshaler := MarshalerForRequest(s, r)
+		s.protoErrorHandler(ctx, s, outboundMarshaler, w, r, ErrUnknownURI)
+	} else {
+		OtherErrorHandler(w, r, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+	}
+}
+
+// GetForwardResponseOptions returns the ForwardResponseOptions associated with this ServeMux.
+func (s *ServeMux) GetForwardResponseOptions() []func(context.Context, http.ResponseWriter, proto.Message) error {
+	return s.forwardResponseOptions
+}
+
+func (s *ServeMux) isPathLengthFallback(r *http.Request) bool {
+	return !s.disablePathLengthFallback && r.Method == "POST" && r.Header.Get("Content-Type") == "application/x-www-form-urlencoded"
+}
+
+type handler struct {
+	pat Pattern
+	h   HandlerFunc
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
new file mode 100644
index 0000000..0905369
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/pattern.go
@@ -0,0 +1,262 @@
+package runtime
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"google.golang.org/grpc/grpclog"
+)
+
+var (
+	// ErrNotMatch indicates that the given HTTP request path does not match to the pattern.
+	ErrNotMatch = errors.New("not match to the path pattern")
+	// ErrInvalidPattern indicates that the given definition of Pattern is not valid.
+	ErrInvalidPattern = errors.New("invalid pattern")
+)
+
+type op struct {
+	code    utilities.OpCode
+	operand int
+}
+
+// Pattern is a template pattern of http request paths defined in github.com/googleapis/googleapis/google/api/http.proto.
+type Pattern struct {
+	// ops is a list of operations
+	ops []op
+	// pool is a constant pool indexed by the operands or vars.
+	pool []string
+	// vars is a list of variables names to be bound by this pattern
+	vars []string
+	// stacksize is the max depth of the stack
+	stacksize int
+	// tailLen is the length of the fixed-size segments after a deep wildcard
+	tailLen int
+	// verb is the VERB part of the path pattern. It is empty if the pattern does not have VERB part.
+	verb string
+	// assumeColonVerb indicates whether a path suffix after a final
+	// colon may only be interpreted as a verb.
+	assumeColonVerb bool
+}
+
+type patternOptions struct {
+	assumeColonVerb bool
+}
+
+// PatternOpt is an option for creating Patterns.
+type PatternOpt func(*patternOptions)
+
+// NewPattern returns a new Pattern from the given definition values.
+// "ops" is a sequence of op codes. "pool" is a constant pool.
+// "verb" is the verb part of the pattern. It is empty if the pattern does not have the part.
+// "version" must be 1 for now.
+// It returns an error if the given definition is invalid.
+func NewPattern(version int, ops []int, pool []string, verb string, opts ...PatternOpt) (Pattern, error) {
+	options := patternOptions{
+		assumeColonVerb: true,
+	}
+	for _, o := range opts {
+		o(&options)
+	}
+
+	if version != 1 {
+		grpclog.Infof("unsupported version: %d", version)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	l := len(ops)
+	if l%2 != 0 {
+		grpclog.Infof("odd number of ops codes: %d", l)
+		return Pattern{}, ErrInvalidPattern
+	}
+
+	var (
+		typedOps        []op
+		stack, maxstack int
+		tailLen         int
+		pushMSeen       bool
+		vars            []string
+	)
+	for i := 0; i < l; i += 2 {
+		op := op{code: utilities.OpCode(ops[i]), operand: ops[i+1]}
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpPushM:
+			if pushMSeen {
+				grpclog.Infof("pushM appears twice")
+				return Pattern{}, ErrInvalidPattern
+			}
+			pushMSeen = true
+			stack++
+		case utilities.OpLitPush:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("negative literal index: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			if pushMSeen {
+				tailLen++
+			}
+			stack++
+		case utilities.OpConcatN:
+			if op.operand <= 0 {
+				grpclog.Infof("negative concat size: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack -= op.operand
+			if stack < 0 {
+				grpclog.Print("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+			stack++
+		case utilities.OpCapture:
+			if op.operand < 0 || len(pool) <= op.operand {
+				grpclog.Infof("variable name index out of bound: %d", op.operand)
+				return Pattern{}, ErrInvalidPattern
+			}
+			v := pool[op.operand]
+			op.operand = len(vars)
+			vars = append(vars, v)
+			stack--
+			if stack < 0 {
+				grpclog.Infof("stack underflow")
+				return Pattern{}, ErrInvalidPattern
+			}
+		default:
+			grpclog.Infof("invalid opcode: %d", op.code)
+			return Pattern{}, ErrInvalidPattern
+		}
+
+		if maxstack < stack {
+			maxstack = stack
+		}
+		typedOps = append(typedOps, op)
+	}
+	return Pattern{
+		ops:             typedOps,
+		pool:            pool,
+		vars:            vars,
+		stacksize:       maxstack,
+		tailLen:         tailLen,
+		verb:            verb,
+		assumeColonVerb: options.assumeColonVerb,
+	}, nil
+}
+
+// MustPattern is a helper function which makes it easier to call NewPattern in variable initialization.
+func MustPattern(p Pattern, err error) Pattern {
+	if err != nil {
+		grpclog.Fatalf("Pattern initialization failed: %v", err)
+	}
+	return p
+}
+
+// Match examines components if it matches to the Pattern.
+// If it matches, the function returns a mapping from field paths to their captured values.
+// If otherwise, the function returns an error.
+func (p Pattern) Match(components []string, verb string) (map[string]string, error) {
+	if p.verb != verb {
+		if p.assumeColonVerb || p.verb != "" {
+			return nil, ErrNotMatch
+		}
+		if len(components) == 0 {
+			components = []string{":" + verb}
+		} else {
+			components = append([]string{}, components...)
+			components[len(components)-1] += ":" + verb
+		}
+		verb = ""
+	}
+
+	var pos int
+	stack := make([]string, 0, p.stacksize)
+	captured := make([]string, len(p.vars))
+	l := len(components)
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush, utilities.OpLitPush:
+			if pos >= l {
+				return nil, ErrNotMatch
+			}
+			c := components[pos]
+			if op.code == utilities.OpLitPush {
+				if lit := p.pool[op.operand]; c != lit {
+					return nil, ErrNotMatch
+				}
+			}
+			stack = append(stack, c)
+			pos++
+		case utilities.OpPushM:
+			end := len(components)
+			if end < pos+p.tailLen {
+				return nil, ErrNotMatch
+			}
+			end -= p.tailLen
+			stack = append(stack, strings.Join(components[pos:end], "/"))
+			pos = end
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			captured[op.operand] = stack[n]
+			stack = stack[:n]
+		}
+	}
+	if pos < l {
+		return nil, ErrNotMatch
+	}
+	bindings := make(map[string]string)
+	for i, val := range captured {
+		bindings[p.vars[i]] = val
+	}
+	return bindings, nil
+}
+
+// Verb returns the verb part of the Pattern.
+func (p Pattern) Verb() string { return p.verb }
+
+func (p Pattern) String() string {
+	var stack []string
+	for _, op := range p.ops {
+		switch op.code {
+		case utilities.OpNop:
+			continue
+		case utilities.OpPush:
+			stack = append(stack, "*")
+		case utilities.OpLitPush:
+			stack = append(stack, p.pool[op.operand])
+		case utilities.OpPushM:
+			stack = append(stack, "**")
+		case utilities.OpConcatN:
+			n := op.operand
+			l := len(stack) - n
+			stack = append(stack[:l], strings.Join(stack[l:], "/"))
+		case utilities.OpCapture:
+			n := len(stack) - 1
+			stack[n] = fmt.Sprintf("{%s=%s}", p.vars[op.operand], stack[n])
+		}
+	}
+	segs := strings.Join(stack, "/")
+	if p.verb != "" {
+		return fmt.Sprintf("/%s:%s", segs, p.verb)
+	}
+	return "/" + segs
+}
+
+// AssumeColonVerbOpt indicates whether a path suffix after a final
+// colon may only be interpreted as a verb.
+func AssumeColonVerbOpt(val bool) PatternOpt {
+	return PatternOpt(func(o *patternOptions) {
+		o.assumeColonVerb = val
+	})
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go
new file mode 100644
index 0000000..a3151e2
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto2_convert.go
@@ -0,0 +1,80 @@
+package runtime
+
+import (
+	"github.com/golang/protobuf/proto"
+)
+
+// StringP returns a pointer to a string whose pointee is same as the given string value.
+func StringP(val string) (*string, error) {
+	return proto.String(val), nil
+}
+
+// BoolP parses the given string representation of a boolean value,
+// and returns a pointer to a bool whose value is same as the parsed value.
+func BoolP(val string) (*bool, error) {
+	b, err := Bool(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Bool(b), nil
+}
+
+// Float64P parses the given string representation of a floating point number,
+// and returns a pointer to a float64 whose value is same as the parsed number.
+func Float64P(val string) (*float64, error) {
+	f, err := Float64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Float64(f), nil
+}
+
+// Float32P parses the given string representation of a floating point number,
+// and returns a pointer to a float32 whose value is same as the parsed number.
+func Float32P(val string) (*float32, error) {
+	f, err := Float32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Float32(f), nil
+}
+
+// Int64P parses the given string representation of an integer
+// and returns a pointer to a int64 whose value is same as the parsed integer.
+func Int64P(val string) (*int64, error) {
+	i, err := Int64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Int64(i), nil
+}
+
+// Int32P parses the given string representation of an integer
+// and returns a pointer to a int32 whose value is same as the parsed integer.
+func Int32P(val string) (*int32, error) {
+	i, err := Int32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Int32(i), err
+}
+
+// Uint64P parses the given string representation of an integer
+// and returns a pointer to a uint64 whose value is same as the parsed integer.
+func Uint64P(val string) (*uint64, error) {
+	i, err := Uint64(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Uint64(i), err
+}
+
+// Uint32P parses the given string representation of an integer
+// and returns a pointer to a uint32 whose value is same as the parsed integer.
+func Uint32P(val string) (*uint32, error) {
+	i, err := Uint32(val)
+	if err != nil {
+		return nil, err
+	}
+	return proto.Uint32(i), err
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
new file mode 100644
index 0000000..ca76324
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
@@ -0,0 +1,106 @@
+package runtime
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/ptypes/any"
+	"github.com/grpc-ecosystem/grpc-gateway/internal"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// StreamErrorHandlerFunc accepts an error as a gRPC error generated via status package and translates it into a
+// a proto struct used to represent error at the end of a stream.
+type StreamErrorHandlerFunc func(context.Context, error) *StreamError
+
+// StreamError is the payload for the final message in a server stream in the event that the server returns an
+// error after a response message has already been sent.
+type StreamError internal.StreamError
+
+// ProtoErrorHandlerFunc handles the error as a gRPC error generated via status package and replies to the request.
+type ProtoErrorHandlerFunc func(context.Context, *ServeMux, Marshaler, http.ResponseWriter, *http.Request, error)
+
+var _ ProtoErrorHandlerFunc = DefaultHTTPProtoErrorHandler
+
+// DefaultHTTPProtoErrorHandler is an implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a Status message marshaled by a Marshaler.
+//
+// Do not set this function to HTTPError variable directly, use WithProtoErrorHandler option instead.
+func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	// return Internal when Marshal failed
+	const fallback = `{"code": 13, "message": "failed to marshal error message"}`
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	w.Header().Del("Trailer")
+
+	contentType := marshaler.ContentType()
+	// Check marshaler on run time in order to keep backwards compatability
+	// An interface param needs to be added to the ContentType() function on
+	// the Marshal interface to be able to remove this check
+	if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
+		pb := s.Proto()
+		contentType = httpBodyMarshaler.ContentTypeFromMessage(pb)
+	}
+	w.Header().Set("Content-Type", contentType)
+
+	buf, merr := marshaler.Marshal(s.Proto())
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", s.Proto(), merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+// DefaultHTTPStreamErrorHandler converts the given err into a *StreamError via
+// default logic.
+//
+// It extracts the gRPC status from err if possible. The fields of the status are
+// used to populate the returned StreamError, and the HTTP status code is derived
+// from the gRPC code via HTTPStatusFromCode. If the given err does not contain a
+// gRPC status, an "Unknown" gRPC code is used and "Internal Server Error" HTTP code.
+func DefaultHTTPStreamErrorHandler(_ context.Context, err error) *StreamError {
+	grpcCode := codes.Unknown
+	grpcMessage := err.Error()
+	var grpcDetails []*any.Any
+	if s, ok := status.FromError(err); ok {
+		grpcCode = s.Code()
+		grpcMessage = s.Message()
+		grpcDetails = s.Proto().GetDetails()
+	}
+	httpCode := HTTPStatusFromCode(grpcCode)
+	return &StreamError{
+		GrpcCode:   int32(grpcCode),
+		HttpCode:   int32(httpCode),
+		Message:    grpcMessage,
+		HttpStatus: http.StatusText(httpCode),
+		Details:    grpcDetails,
+	}
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go
new file mode 100644
index 0000000..5fbba5e
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/query.go
@@ -0,0 +1,391 @@
+package runtime
+
+import (
+	"encoding/base64"
+	"fmt"
+	"net/url"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/grpc-ecosystem/grpc-gateway/utilities"
+	"google.golang.org/grpc/grpclog"
+)
+
+// PopulateQueryParameters populates "values" into "msg".
+// A value is ignored if its key starts with one of the elements in "filter".
+func PopulateQueryParameters(msg proto.Message, values url.Values, filter *utilities.DoubleArray) error {
+	for key, values := range values {
+		re, err := regexp.Compile("^(.*)\\[(.*)\\]$")
+		if err != nil {
+			return err
+		}
+		match := re.FindStringSubmatch(key)
+		if len(match) == 3 {
+			key = match[1]
+			values = append([]string{match[2]}, values...)
+		}
+		fieldPath := strings.Split(key, ".")
+		if filter.HasCommonPrefix(fieldPath) {
+			continue
+		}
+		if err := populateFieldValueFromPath(msg, fieldPath, values); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// PopulateFieldFromPath sets a value in a nested Protobuf structure.
+// It instantiates missing protobuf fields as it goes.
+func PopulateFieldFromPath(msg proto.Message, fieldPathString string, value string) error {
+	fieldPath := strings.Split(fieldPathString, ".")
+	return populateFieldValueFromPath(msg, fieldPath, []string{value})
+}
+
+func populateFieldValueFromPath(msg proto.Message, fieldPath []string, values []string) error {
+	m := reflect.ValueOf(msg)
+	if m.Kind() != reflect.Ptr {
+		return fmt.Errorf("unexpected type %T: %v", msg, msg)
+	}
+	var props *proto.Properties
+	m = m.Elem()
+	for i, fieldName := range fieldPath {
+		isLast := i == len(fieldPath)-1
+		if !isLast && m.Kind() != reflect.Struct {
+			return fmt.Errorf("non-aggregate type in the mid of path: %s", strings.Join(fieldPath, "."))
+		}
+		var f reflect.Value
+		var err error
+		f, props, err = fieldByProtoName(m, fieldName)
+		if err != nil {
+			return err
+		} else if !f.IsValid() {
+			grpclog.Infof("field not found in %T: %s", msg, strings.Join(fieldPath, "."))
+			return nil
+		}
+
+		switch f.Kind() {
+		case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64, reflect.String, reflect.Uint32, reflect.Uint64:
+			if !isLast {
+				return fmt.Errorf("unexpected nested field %s in %s", fieldPath[i+1], strings.Join(fieldPath[:i+1], "."))
+			}
+			m = f
+		case reflect.Slice:
+			if !isLast {
+				return fmt.Errorf("unexpected repeated field in %s", strings.Join(fieldPath, "."))
+			}
+			// Handle []byte
+			if f.Type().Elem().Kind() == reflect.Uint8 {
+				m = f
+				break
+			}
+			return populateRepeatedField(f, values, props)
+		case reflect.Ptr:
+			if f.IsNil() {
+				m = reflect.New(f.Type().Elem())
+				f.Set(m.Convert(f.Type()))
+			}
+			m = f.Elem()
+			continue
+		case reflect.Struct:
+			m = f
+			continue
+		case reflect.Map:
+			if !isLast {
+				return fmt.Errorf("unexpected nested field %s in %s", fieldPath[i+1], strings.Join(fieldPath[:i+1], "."))
+			}
+			return populateMapField(f, values, props)
+		default:
+			return fmt.Errorf("unexpected type %s in %T", f.Type(), msg)
+		}
+	}
+	switch len(values) {
+	case 0:
+		return fmt.Errorf("no value of field: %s", strings.Join(fieldPath, "."))
+	case 1:
+	default:
+		grpclog.Infof("too many field values: %s", strings.Join(fieldPath, "."))
+	}
+	return populateField(m, values[0], props)
+}
+
+// fieldByProtoName looks up a field whose corresponding protobuf field name is "name".
+// "m" must be a struct value. It returns zero reflect.Value if no such field found.
+func fieldByProtoName(m reflect.Value, name string) (reflect.Value, *proto.Properties, error) {
+	props := proto.GetProperties(m.Type())
+
+	// look up field name in oneof map
+	if op, ok := props.OneofTypes[name]; ok {
+		v := reflect.New(op.Type.Elem())
+		field := m.Field(op.Field)
+		if !field.IsNil() {
+			return reflect.Value{}, nil, fmt.Errorf("field already set for %s oneof", props.Prop[op.Field].OrigName)
+		}
+		field.Set(v)
+		return v.Elem().Field(0), op.Prop, nil
+	}
+
+	for _, p := range props.Prop {
+		if p.OrigName == name {
+			return m.FieldByName(p.Name), p, nil
+		}
+		if p.JSONName == name {
+			return m.FieldByName(p.Name), p, nil
+		}
+	}
+	return reflect.Value{}, nil, nil
+}
+
+func populateMapField(f reflect.Value, values []string, props *proto.Properties) error {
+	if len(values) != 2 {
+		return fmt.Errorf("more than one value provided for key %s in map %s", values[0], props.Name)
+	}
+
+	key, value := values[0], values[1]
+	keyType := f.Type().Key()
+	valueType := f.Type().Elem()
+	if f.IsNil() {
+		f.Set(reflect.MakeMap(f.Type()))
+	}
+
+	keyConv, ok := convFromType[keyType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported key type %s in map %s", keyType, props.Name)
+	}
+	valueConv, ok := convFromType[valueType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported value type %s in map %s", valueType, props.Name)
+	}
+
+	keyV := keyConv.Call([]reflect.Value{reflect.ValueOf(key)})
+	if err := keyV[1].Interface(); err != nil {
+		return err.(error)
+	}
+	valueV := valueConv.Call([]reflect.Value{reflect.ValueOf(value)})
+	if err := valueV[1].Interface(); err != nil {
+		return err.(error)
+	}
+
+	f.SetMapIndex(keyV[0].Convert(keyType), valueV[0].Convert(valueType))
+
+	return nil
+}
+
+func populateRepeatedField(f reflect.Value, values []string, props *proto.Properties) error {
+	elemType := f.Type().Elem()
+
+	// is the destination field a slice of an enumeration type?
+	if enumValMap := proto.EnumValueMap(props.Enum); enumValMap != nil {
+		return populateFieldEnumRepeated(f, values, enumValMap)
+	}
+
+	conv, ok := convFromType[elemType.Kind()]
+	if !ok {
+		return fmt.Errorf("unsupported field type %s", elemType)
+	}
+	f.Set(reflect.MakeSlice(f.Type(), len(values), len(values)).Convert(f.Type()))
+	for i, v := range values {
+		result := conv.Call([]reflect.Value{reflect.ValueOf(v)})
+		if err := result[1].Interface(); err != nil {
+			return err.(error)
+		}
+		f.Index(i).Set(result[0].Convert(f.Index(i).Type()))
+	}
+	return nil
+}
+
+func populateField(f reflect.Value, value string, props *proto.Properties) error {
+	i := f.Addr().Interface()
+
+	// Handle protobuf well known types
+	var name string
+	switch m := i.(type) {
+	case interface{ XXX_WellKnownType() string }:
+		name = m.XXX_WellKnownType()
+	case proto.Message:
+		const wktPrefix = "google.protobuf."
+		if fullName := proto.MessageName(m); strings.HasPrefix(fullName, wktPrefix) {
+			name = fullName[len(wktPrefix):]
+		}
+	}
+	switch name {
+	case "Timestamp":
+		if value == "null" {
+			f.FieldByName("Seconds").SetInt(0)
+			f.FieldByName("Nanos").SetInt(0)
+			return nil
+		}
+
+		t, err := time.Parse(time.RFC3339Nano, value)
+		if err != nil {
+			return fmt.Errorf("bad Timestamp: %v", err)
+		}
+		f.FieldByName("Seconds").SetInt(int64(t.Unix()))
+		f.FieldByName("Nanos").SetInt(int64(t.Nanosecond()))
+		return nil
+	case "Duration":
+		if value == "null" {
+			f.FieldByName("Seconds").SetInt(0)
+			f.FieldByName("Nanos").SetInt(0)
+			return nil
+		}
+		d, err := time.ParseDuration(value)
+		if err != nil {
+			return fmt.Errorf("bad Duration: %v", err)
+		}
+
+		ns := d.Nanoseconds()
+		s := ns / 1e9
+		ns %= 1e9
+		f.FieldByName("Seconds").SetInt(s)
+		f.FieldByName("Nanos").SetInt(ns)
+		return nil
+	case "DoubleValue":
+		fallthrough
+	case "FloatValue":
+		float64Val, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			return fmt.Errorf("bad DoubleValue: %s", value)
+		}
+		f.FieldByName("Value").SetFloat(float64Val)
+		return nil
+	case "Int64Value":
+		fallthrough
+	case "Int32Value":
+		int64Val, err := strconv.ParseInt(value, 10, 64)
+		if err != nil {
+			return fmt.Errorf("bad DoubleValue: %s", value)
+		}
+		f.FieldByName("Value").SetInt(int64Val)
+		return nil
+	case "UInt64Value":
+		fallthrough
+	case "UInt32Value":
+		uint64Val, err := strconv.ParseUint(value, 10, 64)
+		if err != nil {
+			return fmt.Errorf("bad DoubleValue: %s", value)
+		}
+		f.FieldByName("Value").SetUint(uint64Val)
+		return nil
+	case "BoolValue":
+		if value == "true" {
+			f.FieldByName("Value").SetBool(true)
+		} else if value == "false" {
+			f.FieldByName("Value").SetBool(false)
+		} else {
+			return fmt.Errorf("bad BoolValue: %s", value)
+		}
+		return nil
+	case "StringValue":
+		f.FieldByName("Value").SetString(value)
+		return nil
+	case "BytesValue":
+		bytesVal, err := base64.StdEncoding.DecodeString(value)
+		if err != nil {
+			return fmt.Errorf("bad BytesValue: %s", value)
+		}
+		f.FieldByName("Value").SetBytes(bytesVal)
+		return nil
+	case "FieldMask":
+		p := f.FieldByName("Paths")
+		for _, v := range strings.Split(value, ",") {
+			if v != "" {
+				p.Set(reflect.Append(p, reflect.ValueOf(v)))
+			}
+		}
+		return nil
+	}
+
+	// Handle Time and Duration stdlib types
+	switch t := i.(type) {
+	case *time.Time:
+		pt, err := time.Parse(time.RFC3339Nano, value)
+		if err != nil {
+			return fmt.Errorf("bad Timestamp: %v", err)
+		}
+		*t = pt
+		return nil
+	case *time.Duration:
+		d, err := time.ParseDuration(value)
+		if err != nil {
+			return fmt.Errorf("bad Duration: %v", err)
+		}
+		*t = d
+		return nil
+	}
+
+	// is the destination field an enumeration type?
+	if enumValMap := proto.EnumValueMap(props.Enum); enumValMap != nil {
+		return populateFieldEnum(f, value, enumValMap)
+	}
+
+	conv, ok := convFromType[f.Kind()]
+	if !ok {
+		return fmt.Errorf("field type %T is not supported in query parameters", i)
+	}
+	result := conv.Call([]reflect.Value{reflect.ValueOf(value)})
+	if err := result[1].Interface(); err != nil {
+		return err.(error)
+	}
+	f.Set(result[0].Convert(f.Type()))
+	return nil
+}
+
+func convertEnum(value string, t reflect.Type, enumValMap map[string]int32) (reflect.Value, error) {
+	// see if it's an enumeration string
+	if enumVal, ok := enumValMap[value]; ok {
+		return reflect.ValueOf(enumVal).Convert(t), nil
+	}
+
+	// check for an integer that matches an enumeration value
+	eVal, err := strconv.Atoi(value)
+	if err != nil {
+		return reflect.Value{}, fmt.Errorf("%s is not a valid %s", value, t)
+	}
+	for _, v := range enumValMap {
+		if v == int32(eVal) {
+			return reflect.ValueOf(eVal).Convert(t), nil
+		}
+	}
+	return reflect.Value{}, fmt.Errorf("%s is not a valid %s", value, t)
+}
+
+func populateFieldEnum(f reflect.Value, value string, enumValMap map[string]int32) error {
+	cval, err := convertEnum(value, f.Type(), enumValMap)
+	if err != nil {
+		return err
+	}
+	f.Set(cval)
+	return nil
+}
+
+func populateFieldEnumRepeated(f reflect.Value, values []string, enumValMap map[string]int32) error {
+	elemType := f.Type().Elem()
+	f.Set(reflect.MakeSlice(f.Type(), len(values), len(values)).Convert(f.Type()))
+	for i, v := range values {
+		result, err := convertEnum(v, elemType, enumValMap)
+		if err != nil {
+			return err
+		}
+		f.Index(i).Set(result)
+	}
+	return nil
+}
+
+var (
+	convFromType = map[reflect.Kind]reflect.Value{
+		reflect.String:  reflect.ValueOf(String),
+		reflect.Bool:    reflect.ValueOf(Bool),
+		reflect.Float64: reflect.ValueOf(Float64),
+		reflect.Float32: reflect.ValueOf(Float32),
+		reflect.Int64:   reflect.ValueOf(Int64),
+		reflect.Int32:   reflect.ValueOf(Int32),
+		reflect.Uint64:  reflect.ValueOf(Uint64),
+		reflect.Uint32:  reflect.ValueOf(Uint32),
+		reflect.Slice:   reflect.ValueOf(Bytes),
+	}
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel
new file mode 100644
index 0000000..7109d79
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/BUILD.bazel
@@ -0,0 +1,21 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+package(default_visibility = ["//visibility:public"])
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "pattern.go",
+        "readerfactory.go",
+        "trie.go",
+    ],
+    importpath = "github.com/grpc-ecosystem/grpc-gateway/utilities",
+)
+
+go_test(
+    name = "go_default_test",
+    size = "small",
+    srcs = ["trie_test.go"],
+    embed = [":go_default_library"],
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go
new file mode 100644
index 0000000..cf79a4d
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/doc.go
@@ -0,0 +1,2 @@
+// Package utilities provides members for internal use in grpc-gateway.
+package utilities
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go
new file mode 100644
index 0000000..dfe7de4
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/pattern.go
@@ -0,0 +1,22 @@
+package utilities
+
+// An OpCode is a opcode of compiled path patterns.
+type OpCode int
+
+// These constants are the valid values of OpCode.
+const (
+	// OpNop does nothing
+	OpNop = OpCode(iota)
+	// OpPush pushes a component to stack
+	OpPush
+	// OpLitPush pushes a component to stack if it matches to the literal
+	OpLitPush
+	// OpPushM concatenates the remaining components and pushes it to stack
+	OpPushM
+	// OpConcatN pops N items from stack, concatenates them and pushes it back to stack
+	OpConcatN
+	// OpCapture pops an item and binds it to the variable
+	OpCapture
+	// OpEnd is the least positive invalid opcode.
+	OpEnd
+)
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/readerfactory.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/readerfactory.go
new file mode 100644
index 0000000..6dd3854
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/readerfactory.go
@@ -0,0 +1,20 @@
+package utilities
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+)
+
+// IOReaderFactory takes in an io.Reader and returns a function that will allow you to create a new reader that begins
+// at the start of the stream
+func IOReaderFactory(r io.Reader) (func() io.Reader, error) {
+	b, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	return func() io.Reader {
+		return bytes.NewReader(b)
+	}, nil
+}
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go
new file mode 100644
index 0000000..c2b7b30
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/utilities/trie.go
@@ -0,0 +1,177 @@
+package utilities
+
+import (
+	"sort"
+)
+
+// DoubleArray is a Double Array implementation of trie on sequences of strings.
+type DoubleArray struct {
+	// Encoding keeps an encoding from string to int
+	Encoding map[string]int
+	// Base is the base array of Double Array
+	Base []int
+	// Check is the check array of Double Array
+	Check []int
+}
+
+// NewDoubleArray builds a DoubleArray from a set of sequences of strings.
+func NewDoubleArray(seqs [][]string) *DoubleArray {
+	da := &DoubleArray{Encoding: make(map[string]int)}
+	if len(seqs) == 0 {
+		return da
+	}
+
+	encoded := registerTokens(da, seqs)
+	sort.Sort(byLex(encoded))
+
+	root := node{row: -1, col: -1, left: 0, right: len(encoded)}
+	addSeqs(da, encoded, 0, root)
+
+	for i := len(da.Base); i > 0; i-- {
+		if da.Check[i-1] != 0 {
+			da.Base = da.Base[:i]
+			da.Check = da.Check[:i]
+			break
+		}
+	}
+	return da
+}
+
+func registerTokens(da *DoubleArray, seqs [][]string) [][]int {
+	var result [][]int
+	for _, seq := range seqs {
+		var encoded []int
+		for _, token := range seq {
+			if _, ok := da.Encoding[token]; !ok {
+				da.Encoding[token] = len(da.Encoding)
+			}
+			encoded = append(encoded, da.Encoding[token])
+		}
+		result = append(result, encoded)
+	}
+	for i := range result {
+		result[i] = append(result[i], len(da.Encoding))
+	}
+	return result
+}
+
+type node struct {
+	row, col    int
+	left, right int
+}
+
+func (n node) value(seqs [][]int) int {
+	return seqs[n.row][n.col]
+}
+
+func (n node) children(seqs [][]int) []*node {
+	var result []*node
+	lastVal := int(-1)
+	last := new(node)
+	for i := n.left; i < n.right; i++ {
+		if lastVal == seqs[i][n.col+1] {
+			continue
+		}
+		last.right = i
+		last = &node{
+			row:  i,
+			col:  n.col + 1,
+			left: i,
+		}
+		result = append(result, last)
+	}
+	last.right = n.right
+	return result
+}
+
+func addSeqs(da *DoubleArray, seqs [][]int, pos int, n node) {
+	ensureSize(da, pos)
+
+	children := n.children(seqs)
+	var i int
+	for i = 1; ; i++ {
+		ok := func() bool {
+			for _, child := range children {
+				code := child.value(seqs)
+				j := i + code
+				ensureSize(da, j)
+				if da.Check[j] != 0 {
+					return false
+				}
+			}
+			return true
+		}()
+		if ok {
+			break
+		}
+	}
+	da.Base[pos] = i
+	for _, child := range children {
+		code := child.value(seqs)
+		j := i + code
+		da.Check[j] = pos + 1
+	}
+	terminator := len(da.Encoding)
+	for _, child := range children {
+		code := child.value(seqs)
+		if code == terminator {
+			continue
+		}
+		j := i + code
+		addSeqs(da, seqs, j, *child)
+	}
+}
+
+func ensureSize(da *DoubleArray, i int) {
+	for i >= len(da.Base) {
+		da.Base = append(da.Base, make([]int, len(da.Base)+1)...)
+		da.Check = append(da.Check, make([]int, len(da.Check)+1)...)
+	}
+}
+
+type byLex [][]int
+
+func (l byLex) Len() int      { return len(l) }
+func (l byLex) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
+func (l byLex) Less(i, j int) bool {
+	si := l[i]
+	sj := l[j]
+	var k int
+	for k = 0; k < len(si) && k < len(sj); k++ {
+		if si[k] < sj[k] {
+			return true
+		}
+		if si[k] > sj[k] {
+			return false
+		}
+	}
+	if k < len(sj) {
+		return true
+	}
+	return false
+}
+
+// HasCommonPrefix determines if any sequence in the DoubleArray is a prefix of the given sequence.
+func (da *DoubleArray) HasCommonPrefix(seq []string) bool {
+	if len(da.Base) == 0 {
+		return false
+	}
+
+	var i int
+	for _, t := range seq {
+		code, ok := da.Encoding[t]
+		if !ok {
+			break
+		}
+		j := da.Base[i] + code
+		if len(da.Check) <= j || da.Check[j] != i+1 {
+			break
+		}
+		i = j
+	}
+	j := da.Base[i] + len(da.Encoding)
+	if len(da.Check) <= j || da.Check[j] != i+1 {
+		return false
+	}
+	return true
+}