Go grpc 基本使用

export GO111MODULE=on
go get github.com/golang/protobuf/protoc-gen-go
export PATH="$PATH:$(go env GOPATH)/bin"
Go to src目录下
git clone -b v1.31.0 https://github.com/grpc/grpc-go
mkdir grpc-go/examples/myproject/pb

创建proto文件：

syntax = "proto3";

package pb;
option go_package = ".;pb";


message HelloRequest {
  string username = 1;
}

message HelloResponse {
  string message = 1;
}

message AddRequest {
  int64 first = 1;
  int64 second = 2;
}

message AddResponse {
  int64 result = 3;
}

message ClientStream {
    bytes stream = 1;
}
message ServerStream {
    bytes stream = 1;
}
service HelloService {
  rpc SayHello(HelloRequest) returns (HelloResponse){}

  rpc Chat(stream ClientStream) returns (stream ServerStream){}

  rpc Add(AddRequest) returns (AddResponse){}
}

protoc --go_out=plugins=grpc:. hello.proto  生成 hello.pb.go文件

编写客户端和服务端程序

mkdir client

package main

import (
    "context"
    "fmt"
    "io"
    "time"

    pb "google.golang.org/grpc/examples/myproject/pb"

    "google.golang.org/grpc"
)

func main() {
    conn, err := grpc.Dial("localhost:6001", grpc.WithInsecure())
    if err != nil {
        fmt.Println(err.Error())
        return
    }
    defer conn.Close()
    c := pb.NewHelloServiceClient(conn)
    r, err := c.Add(context.Background(), &pb.AddRequest{First: 88, Second: 88})
    if err != nil {
        fmt.Println(err.Error())
        return
    }
    fmt.Println(r.Result)

    // chat
    chatClilent, e := c.Chat(context.Background())
    if e != nil {
        fmt.Println(e.Error())
        return
    }
    go func() {
        for {
            stream, e := chatClilent.Recv()
            if e == io.EOF {
                fmt.Println("EOF")
                return
            }
            if e != nil {
                fmt.Println("cuowu")
                return
            }
            fmt.Println("receive from server:", stream.Stream)
        }
    }()
    chatClilent.Send(&pb.ClientStream{
        Stream: newBytes(10, 9, 8, 7),
    })
    select {
    case <-time.After(20 * time.Second):
    }
}

func newBytes(a ...byte) []byte {
    return a
}

mkdir server

package main

import (
    "context"
    "fmt"
    "io"
    "net"

    pb "google.golang.org/grpc/examples/myproject/pb"

    "google.golang.org/grpc"
)

type HelloService struct {
}

func (hs HelloService) Add(ctx context.Context, in *pb.AddRequest) (*pb.AddResponse, error) {
    return &pb.AddResponse{Result: in.First + in.Second}, nil
}
func (hs *HelloService) SayHello(ctx context.Context, req *pb.HelloRequest) (*pb.HelloResponse, error) {
    return &pb.HelloResponse{Message: fmt.Sprintf("你好，%s", req.Username)}, nil
}
func (hs *HelloService) Chat(conn pb.HelloService_ChatServer) error {
    for {
        stream, err := conn.Recv()
        if err == io.EOF {
            fmt.Println("EOF")
            return nil
        }
        if err != nil {
            fmt.Println(err.Error())
            return err
        }
        fmt.Println("receive from client:", stream.Stream)

        conn.Send(&pb.ServerStream{
            Stream: newBytes(1, 2, 3, 4, 5),
        })

        // 关闭连接
        // return nil
    }
    return nil
}

func main() {
    lis, err := net.Listen("tcp", ":6001")
    if err != nil {
        fmt.Println(err.Error())
        return
    }
    s := grpc.NewServer()
    pb.RegisterHelloServiceServer(s, &HelloService{})
    s.Serve(lis)
}

func newBytes(a ...byte) []byte {
    return a
}