新しいRPCフレームワーク、gRPCをGoで試してみる。

syntax = "proto3";

package helloworld;

service Greeter {
	rpc SayHello (HelloRequest) returns (HelloReply){}
}

message HelloRequest{
	string name = 1;
}

message HelloReply {
	string message = 1;
}

$ ./autogen.sh
$ ./configure
$ make
$ make check
$ make install

// Code generated by protoc-gen-go.
// source: helloworld.proto
// DO NOT EDIT!

/*
Package helloworld is a generated protocol buffer package.

It is generated from these files:
	helloworld.proto

It has these top-level messages:
	HelloRequest
	HelloReply
*/
package helloworld

import proto "github.com/golang/protobuf/proto"

import (
	context "golang.org/x/net/context"
	grpc "google.golang.org/grpc"
)

// Reference imports to suppress errors if they are not otherwise used.
var _ context.Context
var _ grpc.ClientConn

// Reference imports to suppress errors if they are not otherwise used.
var _ = proto.Marshal

type HelloRequest struct {
	Name string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
}

func (m *HelloRequest) Reset()         { *m = HelloRequest{} }
func (m *HelloRequest) String() string { return proto.CompactTextString(m) }
func (*HelloRequest) ProtoMessage()    {}

type HelloReply struct {
	Message string `protobuf:"bytes,1,opt,name=message" json:"message,omitempty"`
}

func (m *HelloReply) Reset()         { *m = HelloReply{} }
func (m *HelloReply) String() string { return proto.CompactTextString(m) }
func (*HelloReply) ProtoMessage()    {}

// Client API for Greeter service

type GreeterClient interface {
	SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error)
}

type greeterClient struct {
	cc *grpc.ClientConn
}

func NewGreeterClient(cc *grpc.ClientConn) GreeterClient {
	return &greeterClient{cc}
}

func (c *greeterClient) SayHello(ctx context.Context, in *HelloRequest, opts ...grpc.CallOption) (*HelloReply, error) {
	out := new(HelloReply)
	err := grpc.Invoke(ctx, "/helloworld.Greeter/SayHello", in, out, c.cc, opts...)
	if err != nil {
		return nil, err
	}
	return out, nil
}

// Server API for Greeter service

type GreeterServer interface {
	SayHello(context.Context, *HelloRequest) (*HelloReply, error)
}

func RegisterGreeterServer(s *grpc.Server, srv GreeterServer) {
	s.RegisterService(&_Greeter_serviceDesc, srv)
}

func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, codec grpc.Codec, buf []byte) (interface{}, error) {
	in := new(HelloRequest)
	if err := codec.Unmarshal(buf, in); err != nil {
		return nil, err
	}
	out, err := srv.(GreeterServer).SayHello(ctx, in)
	if err != nil {
		return nil, err
	}
	return out, nil
}

var _Greeter_serviceDesc = grpc.ServiceDesc{
	ServiceName: "helloworld.Greeter",
	HandlerType: (*GreeterServer)(nil),
	Methods: []grpc.MethodDesc{
		{
			MethodName: "SayHello",
			Handler:    _Greeter_SayHello_Handler,
		},
	},
	Streams: []grpc.StreamDesc{},
}

package main

import (
	"flag"
	pb "github.com/wdgk/grpc-sampler/proto"
	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"log"
	"net"
)

var (
	addrFlag = flag.String("addr", ":5000", "Address host:post")
)

type server struct{}

//リクセスト(Name)を受け取り、レスポンス(Message)を返す
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
	log.Printf("New Request: %v", in.String())
	return &pb.HelloReply{Message: "Hello, " + in.Name + "!"}, nil
}

func main() {
　　　   //requestを受け付けるportを指定する
	lis, err := net.Listen("tcp", *addrFlag)

	if err != nil {
		log.Fatalf("boo")
	}

        //新しいgRPCサーバーのインスタンスを作成
	s := grpc.NewServer()
        //gRPCサーバーを保存する
	pb.RegisterGreeterServer(s, &server{})
	s.Serve(lis)
}