A simple LibraryService to demonstrate how to use Bazel+Go+gRPC

A simple library service (server and client).

• Service defined in Protocol Buffer v3 (proto3).
• Programming language The Go Programming Langauge (golang).
• RPC framework gRPC.
• Build tool Bazel.

Pre-work

The following instructions are tested on Ubuntu 16.04 (LTS).

1. Install Bazel

   Bazel is our build tool. It is written in Java. Install Java and then Bazel.

   $ sudo apt-get install bazel

   Complete instructions for intalling Bazel on Ubuntu.

2. Install Git

   Git is our version control system. It is used by Bazel to download some of our external dependencies (like Protocol Buffers, gRPC, and Bazel's Go rules.

   $ sudo apt-get install git

3. (Optional) Install Go

   Go is a programming language and is very good at writting large-scale distributed systems. Our service and client are written in Go.

   $ sudo apt-get install golang-go

   Compelte instructions for installing Go on Ubuntu

4. (Optional) Install Gazelle

   Gazelle is a helper tool that automatically generates Bazel BUILD files for Go and makes your life easier.

   $ go install github.com/bazelbuild/bazel-gazelle/cmd/gazelle@latest

5. (Optional) Install Buildifier

   Bazel Buildtools are helpers tools for Bazel. Buildifier cleans up and formats Bazel build files.

   $ go install github.com/bazelbuild/buildtools/buildifier@latest

Clone

$ git clone [email protected]:ghasemloo/libraryservice.git
$ cd libraryservice

Bazel

Build and Test

$ bazel build ...
$ bazel test ...

Run the server and the client

In one terminal run the server:

$ bazel run server/server -- --logtostderr

In another terminal run the client to send requests to the server:

$ bazel run client/client -- --logtostderr

Go (without Bazel)

Go Module

$ go mod init github.com/ghasemloo/libraryservice
$ go mod tidy

Proto Compiler for Go

Install Protobuf Compiler to generate Go packages for proto files:

$ sudo apt-get install protobuf-compiler
$ go install google.golang.org/protobuf/cmd/[email protected]
$ go install google.golang.org/grpc/cmd/[email protected]

Generated Go Proto Packages

$ protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative ./proto/api/api.proto
$ protoc --go_out=. --go_opt=paths=source_relative --go-grpc_out=. --go-grpc_opt=paths=source_relative ./proto/storage/storage.proto

Build and Test

$ go build ./...
$ go test ./...

Run the server and the client

In two different terminals run:

$ go run ./server/main.go

$ go run ./client/main.go

Gazelle

Updating WORKSPACE.bazel from go.mod:

$ gazelle update-repos --proto_import_prefix="github.com/ghasemloo/libraryservice" --from_file=./go.mod --prune

Creating/updating BUILD.bazel files:

$ gazelle fix -go_prefix github.com/ghasemloo/libraryservice

You can also use Bazel (gazelle commands and paramters are configured in the BUILD.bazel):

$ bazel run //:gazelle-update-repos
$ bazel run //:gazelle

References

• Bazel: http://bazel.build
• Go: https://golang.org
• Google API Style Guide: https://cloud.google.com/apis/design/
• Proto3: https://developers.google.com/protocol-buffers/
• gRPC: https://www.grpc.io/
• gRPC Example: https://grpc.io/docs/languages/go/quickstart/
• Google RPC Status and Canonical Error Codes