golang-grpc

1.安装grpc

//本来一行命令搞定，奈何网络原因
//go get google.golang.org/grpc

//下载google的grpc,曲线救国
git clone https://github.com/grpc/grpc-go.git $GOPATH/src/google.golang.org/grpc

//下载golang/x/中依赖的包
git clone https://github.com/golang/net.git $GOPATH/src/golang.org/x/net
git clone https://github.com/golang/text.git $GOPATH/src/golang.org/x/text
git clone https://github.com/golang/sys.git $GOPATH/src/golang.org/x/sys
//go get -u github.com/golang/protobuf/{proto,protoc-gen-go}  //经过实践发现貌似没什么用，会更新出错

//下载google的protobuf,曲线救国
cd $GOPATH/srcgoogle.golang.org/
git clone https://github.com/protocolbuffers/protobuf-go.git
mv protobuf-go/ protobuf/

cd $GOPATH/src/golang.org
git clone https://github.com/golang/protobuf.git

git clone https://github.com/google/go-genproto.git $GOPATH/src/google.golang.org/genproto
 
cd $GOPATH/src/
go install google.golang.org/grpc  //这块可能环境变量中找不到grpc，如果找不到，cp /bin/grpc  /usr/local/bin

错误：

protoc error while loading shared libraries: libprotobuf.so.17: cannot open shared object file:
解决办法：
export LD_LIBRARY_PATH=/usr/local/lib

2.安装protocal buffer compiler

(1.)github上release版本下载
https://github.com/protocolbuffers/protobuf/releases/tag/v3.11.3 //找对应的版本和操作系统下载，下载后，解压zip包，然后拷贝/bin/protoc 到/usr/local/bin下面
(2.)或者采用源码编译安装

https://github.com/google/protobuf/releases
tar -zxvf xxxx.tar.gz
cd xxxx/
export LD_LIBRARY_PATH=/usr/local/lib   //添加环境变量
./configure
make
make install

3.使用示例

（1.）创建proto文件

syntax = "proto3";

package grpcusage;

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

message HelloRequest {
    string Name = 1;
}

message HelloReply {
    string Message = 1;
}

(2.)生成golang grpc代码

#格式 protoc --go_out=plugins=grpc:{go代码输出路径} {proto文件}
protoc --go_out=plugins=grpc:./ ./helloworld.proto

(3.)编写服务端代码

package main

import (
    "golang.org/x/net/context"
    pb "helloworld"

    "net"
    "log"
    "google.golang.org/grpc"
    "fmt"
)

const (
    port = ":50051"
)

type Server struct {}

func (s *Server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    return &pb.HelloReply{
        Message: "hello " + in.Name,
    }, nil
}

func main() {
    conn, err := net.Listen("tcp", port)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println("grpc server listening at: 50051 port")
    server := grpc.NewServer()
    pb.RegisterHelloServer(server, &Server{})
    server.Serve(conn)
}

(4.)编写客户端代码

package main

import (
    "google.golang.org/grpc"
    "log"
    pb "helloworld"
    "os"
    "context"
        "fmt"
)

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

func main()  {
    conn, err := grpc.Dial(address, grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    defer conn.Close()
    client := pb.NewHelloClient(conn)

    name := defaultName
    if len(os.Args) > 1 {
        name = os.Args[1]
    }
    request, err := client.SayHello(context.Background(), &pb.HelloRequest{Name:name})
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println(request.Message)
}

(5.)分别启动服务端和客户端

go run server.go
go run client.go

相关链接

https://blog.didiyun.com/index.php/2018/12/12/grpc-golang-1/
https://www.jianshu.com/p/e010dae6d11f
https://studygolang.com/articles/15482