main.go

main.go

// Package main implements a server for Greeter service.
package main

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

	"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")
)

// healthz
func healthz(w http.ResponseWriter, req *http.Request) {
	w.WriteHeader(200)
	w.Write([]byte("ok"))
}

// 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("0.0.0.0:%d", *port))
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}

	// Healthz http server
	go func() {
		http.HandleFunc("/healthz", healthz)
		http.ListenAndServe(":8080", nil)
	}()

	s := grpc.NewServer()
	pb.RegisterGreeterServer(s, &server{})
	// Register reflection service on gRPC server.
	reflection.Register(s)
	log.Printf("server listening at %v", lis.Addr())
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}