demo结构如下，基于标准库构建

grpc.png

测试：

1 proto文件生成
> protoc -I . --go_out=plugins=grpc:./idl/proto ./idl/data.proto

2 启动服务端
- 窗口1：
    > go run ./server/server.go

3 测试客户端
- 窗口2：
    > go run ./client/client.go

client.go

package main

import (
    "fmt"
    "golang.org/x/net/context"
    "google.golang.org/grpc"
    "grpc/consts"
    pb "grpc/idl/proto"
)
func main() {
    //连接gRPC服务器
    conn, err := grpc.Dial(consts.Address, grpc.WithInsecure())
    if err != nil {
        fmt.Println(err)
    }
    defer conn.Close()

    //初始化客户端
    c := pb.NewHelloClient(conn)

    //调用方法
    reqBody := new(pb.HelloRequest)
    reqBody.Name = "调用SayHello"
    r, err := c.SayHello(context.Background(), reqBody)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println(r.Message)


    nameReq := new (pb.NameReq)
    nameReq.Name = "调用YourName"
    nameRet,_ := c.YourName(context.Background(), nameReq)
    fmt.Println(nameRet.Ret)
}

consts.go

package consts

const (
    //gRPC服务地址
    Address = "127.0.0.1:8081"
)

data.proto

syntax = "proto3"; //指定proto版本

option go_package = "./;proto";

//SayHello 对应的请求和响应
//定义请求结构
message HelloRequest{
    string name=1;
}
//定义响应结构
message HelloReply{
    string message=1;
}


//YourName 对应的请求和响应
message NameReq{
    string name=1;
}
message NameRes{
    string ret=1;
}

//定义Hello服务
service Hello{
    //定义服务中的方法
    rpc SayHello(HelloRequest) returns (HelloReply){}
    rpc YourName(NameReq) returns (NameRes){}
}

server.go

package main

import (
    "fmt"
    "golang.org/x/net/context"
    "google.golang.org/grpc"
    "grpc/consts"
    pb "grpc/idl/proto"
    "net"
)

//定义一个helloServer并实现约定的接口
type helloService struct{}

func (h helloService) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    resp := new(pb.HelloReply)
    resp.Message = "SayHello：" + in.Name + "."
    return resp, nil
}
func (h helloService) YourName(ctx context.Context, in *pb.NameReq) (*pb.NameRes, error) {
    resp := new(pb.NameRes)
    resp.Ret = "YourName：" + in.Name + "."
    return resp, nil
}

var HelloServer = helloService{}

func main() {
    listen, err := net.Listen("tcp", consts.Address)
    if err != nil {
        fmt.Printf("failed to listen:%v", err)
        return
    }


    //实现gRPC Server
    s := grpc.NewServer()
    //注册helloServer为客户端提供服务
    pb.RegisterHelloServer(s, HelloServer) //内部调用了s.RegisterServer()
    fmt.Println("Listen on " + consts.Address)

    s.Serve(listen)
}

go.mod

module grpc

go 1.17

require (
    golang.org/x/net v0.0.0-20211029224645-99673261e6eb
    google.golang.org/grpc v1.41.0
    google.golang.org/protobuf v1.27.1
)

require (
    github.com/golang/protobuf v1.5.0 // indirect
    golang.org/x/sys v0.0.0-20210423082822-04245dca01da // indirect
    golang.org/x/text v0.3.6 // indirect
    google.golang.org/genproto v0.0.0-20200526211855-cb27e3aa2013 // indirect
)