GRPC

先决条件

• Go
• Protocol buffer compiler, protoc, version 3 https://github.com/protocolbuffers/protobuf/releases/tag/v25.0
• Go plugins for protocol compiler

• `go install google.golang.org/protobuf/cmd/[email protected]`
• `go install google.golang.org/grpc/cmd/[email protected]`

运行实例

• `git clone -b v1.58.2 --depth 1 https://github.com/grpc/grpc-go`
• `cd grpc-go/examples/helloworld`
• `go run greeter_server/main.go`
• `go run greeter_client/main.go`

更新 gRPC service

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
  // Sends another greeting
  rpc SayHelloAgain (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

重新生成 gRPC 代码

protoc --go_out=. --go_opt=paths=source_relative \
    --go-grpc_out=. --go-grpc_opt=paths=source_relative \
    helloworld/helloworld.proto

更新 server

func (s *server) SayHelloAgain(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
	return &pb.HelloReply{Message: "Hello again " + in.GetName()}, nil
}

更新 client

	r, err = c.SayHelloAgain(ctx, &pb.HelloRequest{Name: *name})
	if err != nil {
		log.Fatalf("could not greet: %v", err)
	}
	log.Printf("Greeting: %s", r.GetMessage())