1：安装依赖工具

go install \
    github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway \
    github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-openapiv2 \
    google.golang.org/protobuf/cmd/protoc-gen-go \
    google.golang.org/grpc/cmd/protoc-gen-go-grpc

2：添加依赖的proto文件到项目中，

google/api/annotations.proto

依赖文件仓库地址： https://github.com/googleapis/googleapis

image.png

3： 编写proto 文件：

syntax = "proto3";

package iam.v1;

option go_package = "/proto";

// 导入google/api/annotations.proto
import "google/api/annotations.proto";


message Permission  {
   string user_id = 1;
   string tenant_id = 2;
   string resource = 3;
   string action = 4;
}

message HasPermissionReq {
  Permission permission  =1;
}
message  HasPermissionRes {
   bool ok =1;
}


service IamGrpcService {
  rpc HasPermission (HasPermissionReq) returns (HasPermissionRes) {
    option (google.api.http) = {
      post: "/iam/v1/has_permission"
      body: "*"
    };
  };
}

4： 生成go 文件：

#!/bin/bash


#protoc --go_out=:./ --go-grpc_out=.   *.proto


protoc -I . --grpc-gateway_out ./proto \
 --grpc-gateway_opt logtostderr=true \
 --grpc-gateway_opt paths=source_relative \
  *.proto

5: 编写反向代理服务：

func runGrpcGateway(config *conf.Config) error {
   ctx := context.Background()
   ctx, cancel := context.WithCancel(ctx)
   defer cancel()

   // Register gRPC server endpoint
   // Note: Make sure the gRPC server is running properly and accessible
   mux := runtime.NewServeMux()
   opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
   grpcServerEndpoint := fmt.Sprintf("localhost:%s", config.RpcServer.Port)
   err := proto.RegisterIamGrpcServiceHandlerFromEndpoint(ctx, mux,  grpcServerEndpoint, opts)
   if err != nil {
      log.Error("new grpc gateway reverse server error:" + err.Error())
      return err
   }

   // Start HTTP server (and proxy calls to gRPC server endpoint)
   return http.ListenAndServe(":18081", mux)
}