Migrate to buf from prototool

Why? Because prototool is outdated, and can not run on M1 mac.

There are 2 use cases:

• For services only provide gRPC.
• For services provide both REST and gRPC, which make use of grpc-ecosystem/grpc-gateway.

We need 3 files:

• build.go: need to install protoc-gen-* binaries with pin version in go.mod
• buf.yaml
• buf.gen.yaml

FYI, the libs version I use:

• golang/protobuf v1.5.2
• grpc-ecosystem/grpc-gateway v1.16.0

gRPC only

build.go:

//go:build tools
// +build tools

import (
	_ "github.com/golang/protobuf/protoc-gen-go"
)

buf.yaml:

version: v1
breaking:
  use:
    - FILE
lint:
  use:
    - DEFAULT

buf.gen.yml

version: v1
plugins:
  - name: go
    out: pkg
    opt:
      - plugins=grpc

Update Makefile:

gen:
	go install github.com/golang/protobuf/protoc-gen-go
	go install github.com/bufbuild/buf/cmd/buf@latest
	buf format -w
	buf generate

Then run make gen to check result.

REST and gRPC using grpc-gateway

build.go:

//go:build tools
// +build tools

import (
	_ "github.com/golang/protobuf/protoc-gen-go"
	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway"
	_ "github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger"
)

buf.yaml

version: v1
deps:
  - buf.build/haunt98/googleapis:b38d93f7ade94a698adff9576474ae7c
  - buf.build/haunt98/grpc-gateway:ecf4f0f58aa8496f8a76ed303c6e06c7
breaking:
  use:
    - FILE
lint:
  use:
    - DEFAULT

buf.gen.yaml:

version: v1
plugins:
  - name: go
    out: pkg
    opt:
      - plugins=grpc
  - name: grpc-gateway
    out: pkg
    opt:
      - logtostderr=true
  - name: swagger
    out: .
    opt:
      - logtostderr=true

Update Makefile:

gen:
	go install github.com/golang/protobuf/protoc-gen-go
	go install github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway
	go install github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
	go install github.com/bufbuild/buf/cmd/buf@latest
	buf format -w
	buf mod update
	buf generate

Run make gen to get fun of course.

FAQ

If use vendor:

• Replace buf generate with buf generate --exclude-path vendor.
• Replace buf format -w with buf format -w --exclude-path vendor.

If you use grpc-gateway:

• Replace import "third_party/googleapis/google/api/annotations.proto"; with import "google/api/annotations.proto";
• Delete security_definitions, security, in option (grpc.gateway.protoc_gen_swagger.options.openapiv2_swagger).

The last step is delete prototool.yaml.

If you are not migrate but start new:

• Add buf lint to make sure your proto is good.
• Add buf breaking --against "https://your-grpc-repo-goes-here.git" to make sure each time you update proto, you don't break backward compatibility.

Thanks

• uber/prototool
• bufbuild/buf