Move gRPC instrumentation from go.opentelemetry.io/otel (#189)

* Add google.golang.org/grpc instrumentation from otel repo

Move the existing grpctrace package from the go.opentelemetry.io/otel
repository to here. This is based on the package last modified in:
96a5f8f

This is related to:
https://github.com/open-telemetry/opentelemetry-go/issues/976

* Update package name: grpctrace -> grpc

* Revert back to the v0.10.0 api/standard package for now

* Make into Go module

* Update the Changelog

* Move the gRPC example from otel

Taken from the otel repository at
5438916

* Update packaging of example

* Update go.sum for example

* Add grpc instrumentation to dependabot config

.github/dependabot.yml

@@ -49,6 +49,10 @@ updates:
     directory: "/instrumentation/go.mongodb.org/mongo-driver" # Location of package manifests
     schedule:
       interval: "daily"
+  - package-ecosystem: "gomod" # See documentation for possible values
+    directory: "/instrumentation/google.golang.org/grpc" # Location of package manifests
+    schedule:
+      interval: "daily"
   - package-ecosystem: "gomod" # See documentation for possible values
     directory: "/instrumentation/gopkg.in/macaron.v1" # Location of package manifests
     schedule:

.gitignore

@@ -8,3 +8,5 @@ Thumbs.db
 *.so
 coverage.*
 
+instrumentation/google.golang.org/grpc/example/server/server
+instrumentation/google.golang.org/grpc/example/client/client

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Added
+
+- The `go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc` module has been added to replace the instrumentation that had previoiusly existed in the `go.opentelemetry.io/otel/instrumentation/grpctrace` package. (#189)
+
 ## [0.10.0] - 2020-07-31
 
 This release upgrades its [go.opentelemetry.io/otel](https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.10.0) dependency to v0.10.0 and includes new instrumentation for popular Kafka and Cassandra clients.

instrumentation/google.golang.org/grpc/example/README.md

@@ -0,0 +1,28 @@
+# gRPC Tracing Example
+
+Traces client and server calls via interceptors.
+
+### Compile .proto
+
+Only required if the service definition (.proto) changes.
+
+```sh
+cd ./example/grpc
+
+# protobuf v1.3.2
+protoc -I api --go_out=plugins=grpc,paths=source_relative:./api api/hello-service.proto
+```
+
+### Run server
+
+```sh
+cd ./example/grpc
+
+go run ./server
+```
+
+### Run client
+
+```sh
+go run ./client
+```