准备工作

go get -u google.golang.org/grpc
go get -u github.com/golang/protobuf/protoc-gen-go
export PATH=$PATH:$GOPATH/bin

目录结构

.
├── Makefile
├── client/
│   └── client.go
├── helloworld/
│   ├── helloworld.pb.go
│   └── helloworld.proto
└── server/
    ├── Makefile
    └── server.go

协议

syntax = "proto3";

package helloworld;

// 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;
}

服务器端

//go:generate protoc -I ../helloworld --go_out=plugins=grpc:../helloworld ../helloworld/helloworld.proto
package main

import (
    "log"
    "net"
    pb "simple/helloworld"

    "golang.org/x/net/context"

    "google.golang.org/grpc"
    "google.golang.org/grpc/reflection"
)

const (
    port = ":50051"
)

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

// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    return &pb.HelloReply{Message: "Hello " + in.Name}, nil
}

func main() {
    lis, err := net.Listen("tcp", port)
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }
    s := grpc.NewServer()
    pb.RegisterGreeterServer(s, &server{})
    // Register reflection service on gRPC server.
    reflection.Register(s)
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

服务器端Makefile

BIN=server

all: ${BIN}

${BIN}:
    go generate server.go
    go build ${LDFLAGS} -o ${BIN} server.go

install:
    go install ${LDFLAGS} -o ${BIN} server.go

clean:
    if [ -f ${BIN} ]; then rm ${BIN}; fi

.PHONY: clean install

客户端

package main

import (
    "context"
    "log"

    "google.golang.org/grpc"

    pb "simple/helloworld"
)

const (
    address     = "localhost:50051"
    defaultName = "world"
)

func main() {
    conn, err := grpc.Dial(address, grpc.WithInsecure())
    if err != nil {
        panic(err)
    }

    defer conn.Close()

    c := pb.NewGreeterClient(conn)
    r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: defaultName})
    if err != nil {
        log.Fatal(err)
    }

    log.Printf("r.Message = %+v\n", r.Message)
}

客户端Makefile

BIN=client

all: ${BIN}

${BIN}:
    go build ${LDFLAGS} -o ${BIN} client.go

install:
    go install ${LDFLAGS} -o ${BIN} client.go

clean:
    if [ -f ${BIN} ]; then rm ${BIN}; fi

.PHONY: clean install

Makefile

all:
    cd server/ && ${MAKE}
    cd client/ && ${MAKE}

clean:
    cd server/ && ${MAKE} clean
    cd client/ && ${MAKE} clean

.PHONY: clean install

编译运行

make
server/server &

client/client
# 2017/12/20 20:36:05 r.Message = Hello world