五、gRPC-Gateway
简介
gRPC-Gateway是protoc的一个插件。它读取gRPC服务定义并生成反向代理服务器，该服务器将RESTful JSON API转换为gRPC。此服务器根据gRPC定义中的自定义选项生成。
安装依赖
go get github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway
proto 文件
gateway/pb/gateway.proto 文件；其中 需要 import google/api/annotations.proto；可以将 github.com\grpc-ecosystem\grpc-gateway 下的 third_party\googleapis\google\api 文件拷贝到项目目录下；执行protoc命令
protoc -I=./gateway/pb/ -I=./third_party/ –go_out=./gateway/ –go-grpc_out=./gateway/ -grpc-gateway_out=./gateway/ ./gateway/pb/gateway.proto
syntax = "proto3";
package stream;
option go_package = "pb/;gateway";
import "google/api/annotations.proto";
message Request {
string name = 1;
}
message Reply {
string content = 1;
}
service GatewayDemo {
rpc Gate(Request) returns (Reply) {
option (google.api.http) = {
get: "/v1/gate/{name}"
};
}
}
Server端
server端与正常gRPC服务没什么差别；
package main
import (
"context"
"fmt"
"net"
gateway "github.com/grpc-demo/gateway/pb"
"google.golang.org/grpc"
"google.golang.org/grpc/reflection"
)
type Gate struct {
gateway.UnimplementedGatewayDemoServer
}
func (g Gate) Gate(ctx context.Context, req *gateway.Request) (*gateway.Reply, error) {
return &gateway.Reply{
Content: fmt.Sprintf("name:%s;", req.Name),
}, nil
}
func main() {
server := grpc.NewServer()
gateway.RegisterGatewayDemoServer(server, &Gate{})
reflection.Register(server)
lis, _ := net.Listen("tcp", ":9000")
_ = server.Serve(lis)
}
Http服务端
通过 gateway.RegisterGatewayDemoHandlerFromEndpoint 将http请求代理到给RPC服务；
package main
import (
"context"
"net/http"
gateway "github.com/grpc-demo/gateway/pb"
"github.com/grpc-ecosystem/grpc-gateway/runtime"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
)
const (
// gRPC服务地址
ServerAddr = "127.0.0.1:9000"
ClientAddr = "127.0.0.1:8000"
)
func main() {
ctx, cancelFunc := context.WithCancel(context.Background())
defer cancelFunc()
mux := runtime.NewServeMux()
opts := []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
err := gateway.RegisterGatewayDemoHandlerFromEndpoint(ctx, mux, ServerAddr, opts)
if err != nil {
panic(err)
}
err = http.ListenAndServe(ClientAddr, mux)
if err != nil {
panic(err)
}
}
启动测试
go run server.go
访问 127.0.0.1:8000/v1/gate/grpc 同时也可以通过grpcurl 测试服务端
grpcurl -plaintext -d ‘{“name”:“grpc”}’ localhost:9000 stream.GatewayDemo/Gate
