GRPC的反射机制

install

• go install github.com/fullstorydev/grpcurl/cmd/grpcurl@latest

main.go

package main

import (
    "context"
    "flag"
    "fmt"
    "log"
    "net"

    "google.golang.org/grpc"
    pb "google.golang.org/grpc/examples/helloworld/helloworld"
    "google.golang.org/grpc/reflection"

)

var (
    port = flag.Int("port", 50051, "The server port")
)

// server is used to implement helloworld.GreeterServer.
type server struct {
    pb.UnimplementedGreeterServer
}

// SayHello implements helloworld.GreeterServer
func (s *server) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
    log.Printf("Received: %v", in.GetName())
    return &pb.HelloReply{Message: "Hello " + in.GetName()}, nil
}

func main() {
    flag.Parse()
    lis, err := net.Listen("tcp", fmt.Sprintf(":%d", *port))
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }
    s := grpc.NewServer()
    pb.RegisterGreeterServer(s, &server{})
        reflection.Register(s) // 注册反射服务

    log.Printf("server listening at %v", lis.Addr())
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

test

• go run main.go
• grpcurl --plaintext -d '{"name":"vearne"}' 127.0.0.1:50051 helloworld.Greeter/SayHello

{
  "message": "Hello vearne"
}

• grpcurl --plaintext 127.0.0.1:50051 describe helloworld.Greeter.SayHello

helloworld.Greeter.SayHello is a method:

ref

• https://vearne.cc/archives/39510
• https://github.com/fullstorydev/grpcurl
• https://521github.com/grpc/grpc-go/tree/master/examples/helloworld