gRPC-gateway使用介绍
import (
"context"
"log"
"net"
"net/http"
helloworldpb "github.com/Q1mi/greeter/proto/helloworld"
"github.com/grpc-ecosystem/grpc-gateway/v2/runtime" // 注意v2版本
"google.golang.org/grpc"
"google.golang.org/grpc/credentials/insecure"
)
type server struct {
helloworldpb.UnimplementedGreeterServer
}
func NewServer() *server {
return &server{}
}
func (s *server) SayHello(ctx context.Context, in *helloworldpb.HelloRequest) (*helloworldpb.HelloReply, error) {
return &helloworldpb.HelloReply{Message: in.Name + " world"}, nil
}
func main() {
// Create a listener on TCP port
lis, err := net.Listen("tcp", ":8080")
if err != nil {
log.Fatalln("Failed to listen:", err)
}
// 创建一个gRPC server对象
s := grpc.NewServer()
// 注册Greeter service到server
helloworldpb.RegisterGreeterServer(s, &server{})
// 8080端口启动gRPC Server
log.Println("Serving gRPC on 0.0.0.0:8080")
go func() {
log.Fatalln(s.Serve(lis))
}()
// 创建一个连接到我们刚刚启动的 gRPC 服务器的客户端连接
// gRPC-Gateway 就是通过它来代理请求（将HTTP请求转为RPC请求）
conn, err := grpc.DialContext(
context.Background(),
"0.0.0.0:8080",
grpc.WithBlock(),
grpc.WithTransportCredentials(insecure.NewCredentials()),
)
if err != nil {
log.Fatalln("Failed to dial server:", err)
}
gwmux := runtime.NewServeMux()// <--<--
// 注册Greeter
err = helloworldpb.RegisterGreeterHandler(context.Background(), gwmux, conn)
if err != nil {
log.Fatalln("Failed to register gateway:", err)
}
gwServer := &http.Server{
Addr: ":8090",
Handler: gwmux, // <--<-- 该endpoint接收到http请求时，会调用grpc-gateway内部的方法完成映射
}
// 8090端口提供gRPC-Gateway服务
log.Println("Serving gRPC-Gateway on http://0.0.0.0:8090")
log.Fatalln(gwServer.ListenAndServe())
}