GOlang GRPC使用

1、官网地址 https://grpc.p2hp.com/docs/languages/go/quickstart/index.html 2、编写proto文件

syntax = "proto3";
option go_package = "../grpc";

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (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;
}

3、生成代码文件

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

4、编写服务端代码

package main

import (
    "context"
    "flag"
    "fmt"
    "log"
    "net"

    "google.golang.org/grpc"
    pb "mygin/go_study/grpc"
)

var (
    port = flag.Int("port", 50051, "The server port")
)

// server is used to implement helloworld.GreeterServer.
type server struct {
    pb.UnimplementedGreeterServer
}

// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(_ context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    log.Printf("Received: %v", in.GetName())
    return &pb.HelloReply{Message: "Hello " + in.GetName()}, nil
}

func main() {
    flag.Parse()
    lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }
    s := grpc.NewServer()
    pb.RegisterGreeterServer(s, &server{})
    log.Printf("server listening at %v", lis.Addr())
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

5、编写客户端代码

package main

import (
    "context"
    "flag"
    "log"
    "time"

    "google.golang.org/grpc"
    "google.golang.org/grpc/credentials/insecure"
    pb "mygin/go_study/grpc"
)

const (
    defaultName = "world"
)

var (
    addr = flag.String("addr", "localhost:50051", "the address to connect to")
    name = flag.String("name", defaultName, "Name to greet")
)

func main() {
    flag.Parse()
    // Set up a connection to the server.
    conn, err := grpc.NewClient(*addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
    if err != nil {
        log.Fatalf("did not connect: %v", err)
    }
    defer conn.Close()
    c := pb.NewGreeterClient(conn)

    // Contact the server and print out its response.
    ctx, cancel := context.WithTimeout(context.Background(), time.Second)
    defer cancel()
    r, err := c.SayHello(ctx, &pb.HelloRequest{Name: *name})
    if err != nil {
        log.Fatalf("could not greet: %v", err)
    }
    log.Printf("Greeting: %s", r.GetMessage())
}

6、运行服务端代码 7、运行客户端代码