Golang gRPC 实践（一）

介绍

RPC是远程过程调用（Remote Procedure Call）的缩写形式。SAP系统RPC调用的原理其实很简单，有一些类似于三层构架的C/S系统，第三方的客户程序通过接口调用SAP内部的标准或自定义函数，获得函数返回的数据进行处理后显示或打印。

gRPC，A high-performance, open-source universal RPC framework，Google开源的高性能的RPC框架，基于ProtoBuf序列化协议进行开发，多种语言f支持（Golang、PHP、C++、Java等）支持，面向HTTP/2标准设计。

官方文档：https://grpc.io/about/

安装

go get -u google.golang.org/grpc

wget https://github.com/google/protobuf/releases/download/v2.6.1/protobuf-2.6.1.tar.gz
tar -xzvf protobuf-2.6.1.tar.gz
cd protobuf-2.6.1
./configure --prefix=/usr/local/protobuf
make
make install

vim /etc/profile
export PATH=$PATH:/usr/local/protobuf/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/protobuf/lib

实例

says_rpc.proto

syntax = "proto2";

option cc_generic_services = true;
option java_generic_services = true;
option py_generic_services = true;

package says_rpc;

option go_package = "pb_models/says_rpc";


message RpcRequest {
    required string name = 1;
}

message RpcReply {
    required string message = 1;
}

service Greeter {
    rpc RpcCall(RpcRequest) returns (RpcReply) ;
}

rpc_server.go

package main

import (
   "context"
   "fmt"
   "google.golang.org/grpc"
   pb "gtest/src/pb_models/says_rpc"
   "log"
   "net"
   "protobuf/proto"
)

const(
   Port = ":10010"
)

type server struct {}

func (s *server) RpcCall(Ctx context.Context, In *pb.RpcRequest) (*pb.RpcReply, error) {
   log.Printf("Received : %v", In.GetName())
   Msg := fmt.Sprintf("Hello : %v " , In.GetName())
   return &pb.RpcReply{Message: proto.String(Msg)}, nil
}

func main() {
   Socket, Err := net.Listen("tcp", Port)
   if Err != nil {
      log.Fatalf("failed to listen : %v .", Err)
   }

   Rpc := grpc.NewServer()

   pb.RegisterGreeterServer(Rpc, &server{})

   if Err := Rpc.Serve(Socket); Err != nil {
      log.Fatalf("failed to service : %v .", Err)
   }
}

rpc_client.go

package main

import (
   "context"
   "google.golang.org/grpc"
   pb "gtest/src/pb_models/says_rpc"
   "log"
   "os"
   "protobuf/proto"
   "time"
)

const (
   Address = "localhost:10010"
   DefaultName = "ChengLin Gui"
)

func main() {

   Conn, Err := grpc.Dial(Address, grpc.WithInsecure())
   if Err != nil {
      log.Fatalf("did not connect : %v .", Err)
   }

   defer Conn.Close()

   Client := pb.NewGreeterClient(Conn)

   Name := DefaultName
   if len(os.Args) > 1 {
      Name = os.Args[1]
   }

   Ctx, Cancel := context.WithTimeout(context.Background(), time.Second)
   defer Cancel()
   RpcResult, RpcError := Client.RpcCall(Ctx, &pb.RpcRequest{Name : proto.String(Name)})
   if RpcError != nil {
      log.Fatalf("could not greet %v .", RpcError)
   }

   log.Printf("Greeting: %v .", RpcResult.GetMessage())
}