go-microservice

This is a template for writing a micro-service in go with a server infrastructure. It uses grpc-gateway for endpoints which supports both GRPC & REST interfaces.

All the packages are loosely coupled so just remove them if not required. Make sure to clean imported infra packages from main.go if not used.

Application Components

1. proto
   • Proto definitions for your service. (e.g.)user.proto file defines your service interfaces.
   • This service supports swagger UI. Make sure you change the yourservice.swagger.json within in proto/openapi/index.html
2. dtos
   • Repository models, command structs to communicate between components.
3. services
   • Application files to service the request
4. repository
   • Optional if you access database
5. conf
   • default.yml which used by default. main.go supports custom config file path.

Every component file within this service will have four functions

1. init register your component structure with server to initialize the component with priority or to start your background services.

func init() {
	server.RegisterService(&userRepo{}, server.Low)
}

2. Init function where you intialize your component, register your services with bus for serving other components

func (c *userRepo) Init() (err error) {

	c.addUserMigrations()

	//Register for all the repository requests
	bus.AddHandler(CreateUser)
	bus.AddHandler(ListUsers)
	return nil
}

3. Run (optional)background service. <-ctx.Done() will return err when server recieves termination, use this for safe shutdown.

func (c *GRPC) Run(ctx context.Context) error {
	go func() {
		<-ctx.Done()
		log.Infoln("Stopping Grpc")
		c.grpcServer.GracefulStop()
	}()
	log.WithField("Port", c.grpcPort).Info("Grpc listening...")
	return c.grpcServer.Serve(c.listener)
}

4. OnConfig called when config file is edited

func (service *UserService) OnConfig() {
}

Infra

1. bus
   • Use bus to communicate between components, avoid circular imports
2. cache
   • Three cache libraries are supported. Use the ones you need and remove others.
3. db
   • Supports postgres incremental migration with gorm
4. gateway
   • grpc-gateway wrappers.

Dependencies

1. Generate stubs using buf
   • Buf is a tool that provides various protobuf utilities such as linting, breaking change detection and generation. Please find installation instructions on https://docs.buf.build/installation/.

Installation

1. Run

   • make setup installs all the modules required
   • make generate compiles the proto files
   • go run .

2. Deploy in docker

   • docker-compose up -d