Go语言第八课 gRPC

这篇文件介绍如何构建go语言版gRPC服务端。

环境配置

安装protobuf编译工具（参考https://github.com/google/protobuf/releases）

$ wget https://github.com/google/protobuf/releases/download/v3.5.1/protobuf-cpp-3.5.1.zip

$ unzip protobuf-cpp-3.5.1.zip

####参照protobuf-3.5.1/src/README.md

$ sudo apt-get install autoconf automake libtool curl make g++ unzip
$ cd protobuf-3.5.1
$ ./autogen.sh
$ ./configure
$ make
$ make check
$ sudo make install

$ sudo ldconfig # refresh shared library cache.

安装protoc-gen-go

$ go get -u github.com/golang/protobuf/protoc-gen-go

$ cd $GOPATH/src/github.com/golang/protobuf/protoc-gen-go
$ go build

$ go install

编写代码

参考：

结构如下https://github.com/grpc/grpc-go/tree/master/examples/helloworld

gRPC-test/
├── main.go
└── proto-src
    ├── helloworld.pb.go

    └── helloworld.proto

先看看helloworld.proto文件，这个文件是从https://github.com/grpc/grpc-go/tree/master/examples/helloworld/helloworld里面抄过来的。

// Copyright 2015 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";

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;
}

在文件目录下执行

$ protoc -I ./ --go_out=plugins=grpc:. ./helloworld.proto

我们就可以看到生成的helloworld.pb.go文件。这个文件是自动生成的，不用做任何改动。

然后我们就可以编写main.go文件了（参考https://github.com/grpc/grpc-go/tree/master/examples/helloworld/greeter_server），如下

/*
 *
 * Copyright 2015 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

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

package main

import (
	"log"
	"net"
	"golang.org/x/net/context"
	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"
	pb "./proto-src"
)

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: "this is fuck test ---> 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)
	}
}

执行，发现有几个库死活找不着，这是因为Google在中国被屏蔽。

如果报cannot find package "golang.org/x/***"，那就在$GOPATH/src/golang.org/x/下执行

$ git clone https://github.com/golang/***.git

如果报cannot find package "google.golang.org/genproto/***"，那就在$GOPATH/src/google.golang.org/下执行

$ git clone https://github.com/google/go-genproto.git，并把go-genproto文件夹名称改为genproto

如果报cannot find package "google.golang.org/grpc/***"，那就在$GOPATH/src/google.golang.org/下执行

$ git clone https://github.com/grpc/grpc-go.git，并把grpc-go文件夹名称改为grpc