vendor: add grpc-middleware v1.0.0, not include sub packages

vendor/README.md

@@ -8,4 +8,6 @@ TODO
 - [Protobuf](https://github.com/golang/protobuf): [v1.1.0](https://github.com/golang/protobuf/releases/tag/v1.1.0)
 - [gRPC](https://github.com/grpc/grpc-go): [v1.13.0](https://github.com/grpc/grpc-go/releases/tag/v1.13.0)
 - [grpc-gateway](https://github.com/grpc-ecosystem/grpc-gateway): [v1.4.1](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.4.1)
+- [grpc-middleware](https://github.com/grpc-ecosystem/go-grpc-middleware): [v1.0.0](https://github.com/grpc-ecosystem/go-grpc-middleware/releases/tag/v1.0.0)
+
 

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/

vendor/github.com/grpc-ecosystem/go-grpc-middleware/.travis.yml

@@ -0,0 +1,22 @@
+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 checkdocs
+ - make test
+ 
+after_success:
+  - bash <(curl -s https://codecov.io/bash)

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.

vendor/github.com/grpc-ecosystem/go-grpc-middleware/DOC.md

@@ -0,0 +1,166 @@
+# grpc_middleware
+`import "github.com/grpc-ecosystem/go-grpc-middleware"`
+
+* [Overview](#pkg-overview)
+* [Imported Packages](#pkg-imports)
+* [Index](#pkg-index)
+
+## <a name="pkg-overview">Overview</a>
+`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)
+	}
+
+## <a name="pkg-imports">Imported Packages</a>
+
+- [golang.org/x/net/context](https://godoc.org/golang.org/x/net/context)
+- [google.golang.org/grpc](https://godoc.org/google.golang.org/grpc)
+
+## <a name="pkg-index">Index</a>
+* [func ChainStreamClient(interceptors ...grpc.StreamClientInterceptor) grpc.StreamClientInterceptor](#ChainStreamClient)
+* [func ChainStreamServer(interceptors ...grpc.StreamServerInterceptor) grpc.StreamServerInterceptor](#ChainStreamServer)
+* [func ChainUnaryClient(interceptors ...grpc.UnaryClientInterceptor) grpc.UnaryClientInterceptor](#ChainUnaryClient)
+* [func ChainUnaryServer(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor](#ChainUnaryServer)
+* [func WithStreamServerChain(interceptors ...grpc.StreamServerInterceptor) grpc.ServerOption](#WithStreamServerChain)
+* [func WithUnaryServerChain(interceptors ...grpc.UnaryServerInterceptor) grpc.ServerOption](#WithUnaryServerChain)
+* [type WrappedServerStream](#WrappedServerStream)
+  * [func WrapServerStream(stream grpc.ServerStream) \*WrappedServerStream](#WrapServerStream)
+  * [func (w \*WrappedServerStream) Context() context.Context](#WrappedServerStream.Context)
+
+#### <a name="pkg-files">Package files</a>
+[chain.go](./chain.go) [doc.go](./doc.go) [wrappers.go](./wrappers.go) 
+
+## <a name="ChainStreamClient">func</a> [ChainStreamClient](./chain.go#L136)
+``` go
+func ChainStreamClient(interceptors ...grpc.StreamClientInterceptor) grpc.StreamClientInterceptor
+```
+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.
+
+## <a name="ChainStreamServer">func</a> [ChainStreamServer](./chain.go#L58)
+``` go
+func ChainStreamServer(interceptors ...grpc.StreamServerInterceptor) grpc.StreamServerInterceptor
+```
+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.
+
+## <a name="ChainUnaryClient">func</a> [ChainUnaryClient](./chain.go#L97)
+``` go
+func ChainUnaryClient(interceptors ...grpc.UnaryClientInterceptor) grpc.UnaryClientInterceptor
+```
+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.
+
+## <a name="ChainUnaryServer">func</a> [ChainUnaryServer](./chain.go#L18)
+``` go
+func ChainUnaryServer(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor
+```
+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.
+
+## <a name="WithStreamServerChain">func</a> [WithStreamServerChain](./chain.go#L181)
+``` go
+func WithStreamServerChain(interceptors ...grpc.StreamServerInterceptor) grpc.ServerOption
+```
+WithStreamServerChain is a grpc.Server config option that accepts multiple stream interceptors.
+Basically syntactic sugar.
+
+## <a name="WithUnaryServerChain">func</a> [WithUnaryServerChain](./chain.go#L175)
+``` go
+func WithUnaryServerChain(interceptors ...grpc.UnaryServerInterceptor) grpc.ServerOption
+```
+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.
+
+## <a name="WrappedServerStream">type</a> [WrappedServerStream](./wrappers.go#L12-L16)
+``` go
+type WrappedServerStream struct {
+    grpc.ServerStream
+    // WrappedContext is the wrapper's own Context. You can assign it.
+    WrappedContext context.Context
+}
+```
+WrappedServerStream is a thin wrapper around grpc.ServerStream that allows modifying context.
+
+### <a name="WrapServerStream">func</a> [WrapServerStream](./wrappers.go#L24)
+``` go
+func WrapServerStream(stream grpc.ServerStream) *WrappedServerStream
+```
+WrapServerStream returns a ServerStream that has the ability to overwrite context.
+
+### <a name="WrappedServerStream.Context">func</a> (\*WrappedServerStream) [Context](./wrappers.go#L19)
+``` go
+func (w *WrappedServerStream) Context() context.Context
+```
+Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
+
+- - -
+Generated by [godoc2ghmd](https://github.com/GandalfUK/godoc2ghmd)

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

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"

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
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+      to the Licensor or its representatives, including but not limited to
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+
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+
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+
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+   limitations under the License.

vendor/github.com/grpc-ecosystem/go-grpc-middleware/README.md

@@ -0,0 +1,86 @@
+# Go gRPC Middleware
+
+[![Travis Build](https://travis-ci.org/grpc-ecosystem/go-grpc-middleware.svg?branch=master)](https://travis-ci.org/grpc-ecosystem/go-grpc-middleware)
+[![Go Report Card](https://goreportcard.com/badge/github.com/grpc-ecosystem/go-grpc-middleware)](https://goreportcard.com/report/github.com/grpc-ecosystem/go-grpc-middleware)
+[![GoDoc](http://img.shields.io/badge/GoDoc-Reference-blue.svg)](https://godoc.org/github.com/grpc-ecosystem/go-grpc-middleware)
+[![SourceGraph](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-middleware/-/badge.svg)](https://sourcegraph.com/github.com/grpc-ecosystem/go-grpc-middleware/?badge)
+[![codecov](https://codecov.io/gh/grpc-ecosystem/go-grpc-middleware/branch/master/graph/badge.svg)](https://codecov.io/gh/grpc-ecosystem/go-grpc-middleware)
+[![Apache 2.0 License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](LICENSE)
+[![quality: production](https://img.shields.io/badge/quality-production-orange.svg)](#status)
+[![Slack](slack.png)](https://join.slack.com/t/improbable-eng/shared_invite/enQtMzQ1ODcyMzQ5MjM4LWY5ZWZmNGM2ODc5MmViNmQ3ZTA3ZTY3NzQwOTBlMTkzZmIxZTIxODk0OWU3YjZhNWVlNDU3MDlkZGViZjhkMjc)
+
+[gRPC Go](https://github.com/grpc/grpc-go) Middleware: interceptors, helpers, utilities.
+
+**Important** The repo recently moved to `github.com/grpc-ecosystem/go-grpc-middleware`, please update your import paths.
+
+## 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. See [Documentation](DOC.md), but 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.

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...))
+}

vendor/github.com/grpc-ecosystem/go-grpc-middleware/chain_test.go

@@ -0,0 +1,172 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_middleware
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+)
+
+var (
+	someServiceName  = "SomeService.StreamMethod"
+	parentUnaryInfo  = &grpc.UnaryServerInfo{FullMethod: someServiceName}
+	parentStreamInfo = &grpc.StreamServerInfo{
+		FullMethod:     someServiceName,
+		IsServerStream: true,
+	}
+	someValue     = 1
+	parentContext = context.WithValue(context.TODO(), "parent", someValue)
+)
+
+func TestChainUnaryServer(t *testing.T) {
+	input := "input"
+	output := "output"
+
+	first := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		requireContextValue(t, ctx, "parent", "first interceptor must know the parent context value")
+		require.Equal(t, parentUnaryInfo, info, "first interceptor must know the someUnaryServerInfo")
+		ctx = context.WithValue(ctx, "first", 1)
+		return handler(ctx, req)
+	}
+	second := func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		requireContextValue(t, ctx, "parent", "second interceptor must know the parent context value")
+		requireContextValue(t, ctx, "first", "second interceptor must know the first context value")
+		require.Equal(t, parentUnaryInfo, info, "second interceptor must know the someUnaryServerInfo")
+		ctx = context.WithValue(ctx, "second", 1)
+		return handler(ctx, req)
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		require.EqualValues(t, input, req, "handler must get the input")
+		requireContextValue(t, ctx, "parent", "handler must know the parent context value")
+		requireContextValue(t, ctx, "first", "handler must know the first context value")
+		requireContextValue(t, ctx, "second", "handler must know the second context value")
+		return output, nil
+	}
+
+	chain := ChainUnaryServer(first, second)
+	out, _ := chain(parentContext, input, parentUnaryInfo, handler)
+	require.EqualValues(t, output, out, "chain must return handler's output")
+}
+
+func TestChainStreamServer(t *testing.T) {
+	someService := &struct{}{}
+	recvMessage := "received"
+	sentMessage := "sent"
+	outputError := fmt.Errorf("some error")
+
+	first := func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		requireContextValue(t, stream.Context(), "parent", "first interceptor must know the parent context value")
+		require.Equal(t, parentStreamInfo, info, "first interceptor must know the parentStreamInfo")
+		require.Equal(t, someService, srv, "first interceptor must know someService")
+		wrapped := WrapServerStream(stream)
+		wrapped.WrappedContext = context.WithValue(stream.Context(), "first", 1)
+		return handler(srv, wrapped)
+	}
+	second := func(srv interface{}, stream grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		requireContextValue(t, stream.Context(), "parent", "second interceptor must know the parent context value")
+		requireContextValue(t, stream.Context(), "parent", "second interceptor must know the first context value")
+		require.Equal(t, parentStreamInfo, info, "second interceptor must know the parentStreamInfo")
+		require.Equal(t, someService, srv, "second interceptor must know someService")
+		wrapped := WrapServerStream(stream)
+		wrapped.WrappedContext = context.WithValue(stream.Context(), "second", 1)
+		return handler(srv, wrapped)
+	}
+	handler := func(srv interface{}, stream grpc.ServerStream) error {
+		require.Equal(t, someService, srv, "handler must know someService")
+		requireContextValue(t, stream.Context(), "parent", "handler must know the parent context value")
+		requireContextValue(t, stream.Context(), "first", "handler must know the first context value")
+		requireContextValue(t, stream.Context(), "second", "handler must know the second context value")
+		require.NoError(t, stream.RecvMsg(recvMessage), "handler must have access to stream messages")
+		require.NoError(t, stream.SendMsg(sentMessage), "handler must be able to send stream messages")
+		return outputError
+	}
+	fakeStream := &fakeServerStream{ctx: parentContext, recvMessage: recvMessage}
+	chain := ChainStreamServer(first, second)
+	err := chain(someService, fakeStream, parentStreamInfo, handler)
+	require.Equal(t, outputError, err, "chain must return handler's error")
+	require.Equal(t, sentMessage, fakeStream.sentMessage, "handler's sent message must propagate to stream")
+}
+
+func TestChainUnaryClient(t *testing.T) {
+	ignoredMd := metadata.Pairs("foo", "bar")
+	parentOpts := []grpc.CallOption{grpc.Header(&ignoredMd)}
+	reqMessage := "request"
+	replyMessage := "reply"
+	outputError := fmt.Errorf("some error")
+
+	first := func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		requireContextValue(t, ctx, "parent", "first must know the parent context value")
+		require.Equal(t, someServiceName, method, "first must know someService")
+		require.Len(t, opts, 1, "first should see parent CallOptions")
+		wrappedCtx := context.WithValue(ctx, "first", 1)
+		return invoker(wrappedCtx, method, req, reply, cc, opts...)
+	}
+	second := func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		requireContextValue(t, ctx, "parent", "second must know the parent context value")
+		require.Equal(t, someServiceName, method, "second must know someService")
+		require.Len(t, opts, 1, "second should see parent CallOptions")
+		wrappedOpts := append(opts, grpc.FailFast(true))
+		wrappedCtx := context.WithValue(ctx, "second", 1)
+		return invoker(wrappedCtx, method, req, reply, cc, wrappedOpts...)
+	}
+	invoker := func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, opts ...grpc.CallOption) error {
+		require.Equal(t, someServiceName, method, "invoker must know someService")
+		requireContextValue(t, ctx, "parent", "invoker must know the parent context value")
+		requireContextValue(t, ctx, "first", "invoker must know the first context value")
+		requireContextValue(t, ctx, "second", "invoker must know the second context value")
+		require.Len(t, opts, 2, "invoker should see both CallOpts from second and parent")
+		return outputError
+	}
+	chain := ChainUnaryClient(first, second)
+	err := chain(parentContext, someServiceName, reqMessage, replyMessage, nil, invoker, parentOpts...)
+	require.Equal(t, outputError, err, "chain must return invokers's error")
+}
+
+func TestChainStreamClient(t *testing.T) {
+	ignoredMd := metadata.Pairs("foo", "bar")
+	parentOpts := []grpc.CallOption{grpc.Header(&ignoredMd)}
+	clientStream := &fakeClientStream{}
+	fakeStreamDesc := &grpc.StreamDesc{ClientStreams: true, ServerStreams: true, StreamName: someServiceName}
+
+	first := func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		requireContextValue(t, ctx, "parent", "first must know the parent context value")
+		require.Equal(t, someServiceName, method, "first must know someService")
+		require.Len(t, opts, 1, "first should see parent CallOptions")
+		wrappedCtx := context.WithValue(ctx, "first", 1)
+		return streamer(wrappedCtx, desc, cc, method, opts...)
+	}
+	second := func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		requireContextValue(t, ctx, "parent", "second must know the parent context value")
+		require.Equal(t, someServiceName, method, "second must know someService")
+		require.Len(t, opts, 1, "second should see parent CallOptions")
+		wrappedOpts := append(opts, grpc.FailFast(true))
+		wrappedCtx := context.WithValue(ctx, "second", 1)
+		return streamer(wrappedCtx, desc, cc, method, wrappedOpts...)
+	}
+	streamer := func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		require.Equal(t, someServiceName, method, "streamer must know someService")
+		require.Equal(t, fakeStreamDesc, desc, "streamer must see the right StreamDesc")
+
+		requireContextValue(t, ctx, "parent", "streamer must know the parent context value")
+		requireContextValue(t, ctx, "first", "streamer must know the first context value")
+		requireContextValue(t, ctx, "second", "streamer must know the second context value")
+		require.Len(t, opts, 2, "streamer should see both CallOpts from second and parent")
+		return clientStream, nil
+	}
+	chain := ChainStreamClient(first, second)
+	someStream, err := chain(parentContext, fakeStreamDesc, nil, someServiceName, streamer, parentOpts...)
+	require.NoError(t, err, "chain must not return an error as nothing there reutrned it")
+	require.Equal(t, clientStream, someStream, "chain must return invokers's clientstream")
+}
+
+func requireContextValue(t *testing.T, ctx context.Context, key string, msg ...interface{}) {
+	val := ctx.Value(key)
+	require.NotNil(t, val, msg...)
+	require.Equal(t, someValue, val, msg...)
+}

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

vendor/github.com/grpc-ecosystem/go-grpc-middleware/makefile

@@ -0,0 +1,22 @@
+SHELL="/bin/bash"
+
+GOFILES_NOVENDOR = $(shell go list ./... | grep -v /vendor/)
+
+all: vet fmt docs test
+
+docs:
+	./scripts/docs.sh generate
+
+checkdocs:
+	./scripts/docs.sh check
+
+fmt:
+	go fmt $(GOFILES_NOVENDOR)
+
+vet:
+	go vet $(GOFILES_NOVENDOR)
+
+test: vet
+	./scripts/test_all.sh
+
+.PHONY: all docs validate test

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()}
+}

vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers_test.go

@@ -0,0 +1,52 @@
+// Copyright 2016 Michal Witkowski. All Rights Reserved.
+// See LICENSE for licensing terms.
+
+package grpc_middleware
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"golang.org/x/net/context"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+)
+
+func TestWrapServerStream(t *testing.T) {
+	ctx := context.WithValue(context.TODO(), "something", 1)
+	fake := &fakeServerStream{ctx: ctx}
+	wrapped := WrapServerStream(fake)
+	assert.NotNil(t, wrapped.Context().Value("something"), "values from fake must propagate to wrapper")
+	wrapped.WrappedContext = context.WithValue(wrapped.Context(), "other", 2)
+	assert.NotNil(t, wrapped.Context().Value("other"), "values from wrapper must be set")
+}
+
+type fakeServerStream struct {
+	grpc.ServerStream
+	ctx         context.Context
+	recvMessage interface{}
+	sentMessage interface{}
+}
+
+func (f *fakeServerStream) Context() context.Context {
+	return f.ctx
+}
+
+func (f *fakeServerStream) SendMsg(m interface{}) error {
+	if f.sentMessage != nil {
+		return grpc.Errorf(codes.AlreadyExists, "fakeServerStream only takes one message, sorry")
+	}
+	f.sentMessage = m
+	return nil
+}
+
+func (f *fakeServerStream) RecvMsg(m interface{}) error {
+	if f.recvMessage == nil {
+		return grpc.Errorf(codes.NotFound, "fakeServerStream has no message, sorry")
+	}
+	return nil
+}
+
+type fakeClientStream struct {
+	grpc.ClientStream
+}