go-bazel

A Bazel scaffold template for golang / protobuf+grpc mono repository.

Features

Multi golang microservices in the mono repo
Single build pipeline
Shared golang library
Shared grpc/protobuf library
Automatic release GitHub workflow action
- macOS and Linux builds

A hypothetical setup

A cli ServiceA calling ServiceB grpc method Sum(int32, inte32)
A ServiceB serving the Sum method over grpc.

Step 1: Install Bazel

macOS: https://bazel.build/install/os-x
Ubuntu: https://bazel.build/install/ubuntu

Step 2: Build it

Run the complete build pipeline using:

sh
bazel build //...

Note: The first build will take a moment. No worries, you will see the Bazel mono repo benefits later.

Step 3: Run to see the result

In one terminal, run the grpc serving ServiceA:

sh
bazel run services/servicea :42042

In another terminal, run the client ServiceB:

sh
bazel run services/serviceb :42042

You should see the result. Protobuf + grpc built, services binaries built as well.
The built binaries are in the /bazel-bin directory in their respective sub
directories.

Protobuf/grpc caveats

There is a little caveat with proto when using Bazel. The golang generated proto
files are in the bazel-bin build folder (as they are result of the build, not a
source). So they are not accessible to your IDE. There is an official issue.
Until solved, the workaround is:

For every proto service:
Run Bazel to generate the proto golang implementation:
```
sh
bazel run //proto/[service]
```

Manually copy generated implementation back to the proto/[service] directory:

sh
cp ./bazel-bin/proto/[service]/[service]_go_proto_/github.com/jankremlacek/go-bazel/proto/[service]/*.pb.go ./proto/[service]/

Also, you have to exclude the copied file from the Bazel build. Create file /proto/[service]/.bazelignore and put there all generated [filename].pb.go files.

Note: Of course, this process can be automated.

Additonal commands

Build BUILD.bazel build files using Gazelle:
```
sh
bazel run //:gazelle
```
Update Gazelle golang dependencies using:
```
sh
bazel run //:gazelle-update-repos
```
Test whole pipeline using:
```
sh
bazel test //...
```