Example Bazel repo with Gazelle

The purpose of this repo is to learn how to configure Gazelle to auto-generate BUILD files and rules for a Golang application which includes .proto files.

Setup

The following is required to be installed in order to build this repo:

• Golang 1.17.3
• Bazelisk version 1.10.1
• Linux-based 64-bit system (recommended)

Build app

$ bazel build //...

Useful commands

• Create/update all BUILD.bazel files automatically:

  bazel run //:gazelle
  

• Add a new go_repository() dependency:

  bazel run //:gazelle -- update-repos -build_file_proto_mode=disable_global -to_macro=deps.bzl%go_dependencies <repo url>
  

Compilers

The default gRPC compiler is @io_bazel_rules_go//proto:go_grpc.

In order to support creation of gRPC *.pb.gw.go files, I've added another compiler via a Gazelle directive:

# gazelle:go_grpc_compilers @io_bazel_rules_go//proto:go_grpc,@com_github_grpc_ecosystem_grpc_gateway//protoc-gen-grpc-gateway:go_gen_grpc_gateway

I've also needed to use the update-repos Gazelle command to add this new repo and its deps to the deps.bzl using by WORKSPACE for dependency resolution.

$ bazel run //:gazelle -- update-repos -build_file_proto_mode=disable_global -to_macro=deps.bzl%go_dependencies github.com/grpc-ecosystem/grpc-gateway 

$ bazel run //:gazelle -- update-repos -build_file_proto_mode=disable_global -to_macro=deps.bzl%go_dependencies github.com/ghodss/yaml

See more about directives: https://github.com/bazelbuild/bazel-gazelle/tree/v0.24.0#directives

Bazel Versions

The version of Bazel is set in the .bazeliskrc file.