grpcserver

README

gRPC Server example tutorial

Run instructions

run go run main.go to start a grpc server on port 8080

this will start the application which contains one module grpcserver and based on the config.dist.yml listens to port 8080

then you can use the proto definition (pkg/grpcserver/proto/helloworld/v1/helloworld.proto) to make some test requests (you can use a tool like Kreya for that)

The default configuration also includes the health check server, you can change this behavior by setting the grpc_server.health.enabled flag in the configuration to false.

Settings

You can configure the gRPC server by adding the following snippet in your config file or the Environment variables

grpc_server:
  default:
      port: 8080
      health:
        enabled: true

Basic usage

You have to add the gRPC Server module to your kernel

app := application.New()
app.Add("grpc_server", grpcserver.New(service.Definer))

You have to provide a Definer which is responsible to add the services to the gRPC Server

to generate the services from the .proto definition you can use

protoc --go_opt=paths=source_relative --go_out=plugins=grpc:. helloworld.proto

tip: you can add the command to a gen.go which you can use by calling go generate gen.go command from your CLI whenever you want to regenerate the services and the serialization/deserialization methods

example:

//go:build ignore

package protobuf

//go:generate protoc --go_opt=paths=source_relative --go_out=plugins=grpc:. helloworld.proto

func Definer(_ context.Context, config cfg.Config, logger log.Logger) (*grpcserver.Definitions, error) {
	defs := &grpcserver.Definitions{}

	greeter := NewGreeterService(config, logger)

	defs.Add(GreeterServiceName, greeterRegistrant(greeter))

	return defs, nil
}

func greeterRegistrant(greeterServer protobuf.GreeterServer) grpcserver.Registrant {
	return func(server *grpc.Server) error {
		protobuf.RegisterGreeterServer(server, greeterServer)

		return nil
	}
}

if you want to have a custom health status logic you can use the grpcserver.Definitions.AddWithHealthCheckCallbck() function and pass a grpcserver.HealthCheckCallback as a third argument

defs.AddWithHealthCheckCallback(GreeterServiceName, greeterRegistrant(greeter), greeter.CustomHealthCheck)

the example service has a count that increases every time a hello request happens. After 10 requests the health check returns NOT_SERVING and the server gracefully shuts down.