4.【go-kit教程】go-kit集成grpc和protobuf

环境准备

• gokit工具集：go get github.com/go-kit/kit；
• http请求路由组件：go get github.com/gorilla/mux；
• grpc：参考博客 https://bigox.top/pages/39b3f2/
• protobuf：参考博客 https://bigox.top/pages/8deba5/

目录结构

.
├── pb
│   └── hello.proto
├── cmd
│   └── server
│       └── main.go
├── pkg
│   ├── endpoint.go
│   ├── service.go
│   └── transport.go
└── go.mod

定义api（protobuf）

1. 编写协议文件在 pb 目录下创建 hello.proto 文件，内容如下：

   protobufCopy code
   syntax = "proto3";
   
   package pb;
   
   service HelloService {
     rpc SayHello (HelloRequest) returns (HelloResponse);
   }
   
   message HelloRequest {
     string name = 1;
   }
   
   message HelloResponse {
     string message = 1;
   }
   

   • 该协议文件定义了一个名为 HelloService 的服务，该服务只有一个方法 SayHello，它需要一个 HelloRequest 参数并返回一个 HelloResponse 结构体。

2. 在项目根目录下运行以下命令生成 gRPC 代码(生成代码在pb文件夹目录下)：

   protoc --go-grpc_out=./pb --go_out=./pb ./pb/hello.proto
   
   # 以下是生成的文件
   ─ pb
      ├── hello.pb.go
      ├── hello.proto
      └── hello_grpc.pb.go
   
   

grpcServer

• main.go

  package main
  
  import (
  	"fmt"
  	"github.com/go-kit/kit/log"
  	"github.com/go-kit/kit/log/level"
  	"google.golang.org/grpc"
  	pb "kit-grpc/pb"
  	"kit-grpc/pkg"
  	"net"
  	"os"
  )
  
  func main() {
  
  	logger := log.NewLogfmtLogger(os.Stderr)
  
  	ln, err := net.Listen("tcp", "127.0.0.1:9090")
  	if err != nil {
  		level.Error(logger).Log("err", err)
  		os.Exit(-1)
  	}
  
  	endpoints := pkg.MakeEndpoints(pkg.HelloService{})
  	grpcServer := pkg.NewGRPCServer(endpoints, logger)
  
  	grpc := grpc.NewServer()
  	pb.RegisterHelloServiceServer(grpc, grpcServer)
  	err = grpc.Serve(ln)
  	if err != nil {
  		fmt.Printf("failed to serve: %v", err)
  		return
  	}
  }
  
  

• service.go

  package pkg
  
  import "context"
  
  type Service interface {
  	SayHello(ctx context.Context, name string) (string, error)
  }
  
  type HelloService struct{}
  
  func (s HelloService) SayHello(ctx context.Context, name string) (string, error) {
  	return "Hello, " + name + "!", nil
  }
  
  

• endpoint.go

  package pkg
  
  import (
  	"context"
  	"github.com/go-kit/kit/endpoint"
  	pb "kit-grpc/pb"
  )
  
  type Endpoints struct {
  	SayHello endpoint.Endpoint
  }
  
  func MakeEndpoints(s Service) Endpoints {
  	return Endpoints{
  		SayHello: makeSayHelloEndpoint(s),
  	}
  }
  
  func makeSayHelloEndpoint(s Service) endpoint.Endpoint {
  	return func(ctx context.Context, request interface{}) (interface{}, error) {
  		req := request.(*pb.HelloRequest)
  		res, err := s.SayHello(ctx, req.Name)
  		if err != nil {
  			return nil, err
  		}
  		return pb.HelloResponse{
  			Message: res,
  		}, nil
  	}
  }
  
  

• transport.go

  package pkg
  
  import (
  	"context"
  	"github.com/go-kit/kit/log"
  	"github.com/go-kit/kit/transport/grpc"
  	pb "kit-grpc/pb"
  )
  
  func NewGRPCServer(endpoints Endpoints, logger log.Logger) pb.HelloServiceServer {
  	options := []grpc.ServerOption{}
  	return &grpcServer{
  		sayHello: grpc.NewServer(
  			endpoints.SayHello,
  			decodeHelloRequest,
  			encodeHelloResponse,
  			options...,
  		),
  	}
  }
  
  func decodeHelloRequest(_ context.Context, request interface{}) (interface{}, error) {
  	req := request.(*pb.HelloRequest)
  	return &pb.HelloRequest{Name: req.Name}, nil
  }
  
  func encodeHelloResponse(_ context.Context, response interface{}) (interface{}, error) {
  	res := response.(pb.HelloResponse)
  	return &pb.HelloResponse{Message: res.Message}, nil
  }
  
  type grpcServer struct {
  	pb.UnimplementedHelloServiceServer
  	sayHello grpc.Handler
  }
  
  func (s *grpcServer) SayHello(ctx context.Context, req *pb.HelloRequest) (*pb.HelloResponse, error) {
  	_, resp, err := s.sayHello.ServeGRPC(ctx, req)
  	if err != nil {
  		return nil, err
  	}
  	return resp.(*pb.HelloResponse), nil
  }
  
  

grpcClient

/**
 * @date: 2023/2/19
 * @desc:
 */

package main

import (
	"context"
	"google.golang.org/grpc"
	pb "kit-grpc/pb"
	"log"
)

func main() {
	conn, err := grpc.Dial("127.0.0.1:9090", grpc.WithInsecure())
	if err != nil {
		log.Fatal("failed to dial server: ", err)
	}
	defer conn.Close()

	client := pb.NewHelloServiceClient(conn)

	resp, err := client.SayHello(context.Background(), &pb.HelloRequest{Name: "Alice"})
	if err != nil {
		log.Fatal("failed to call SayHello: ", err)
	}

	log.Println(resp.Message)
}

完整代码

• https://github.com/daniuEvan/go-kit-demo/tree/main/kit-grpc-demo