Example code doesn't gracefully shutdown

[bkane-msft]

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Please see the FAQ in our main README.md, then answer the questions below
before submitting your issue.

What version of gRPC are you using?

https://github.com/grpc/grpc-go/blob/89737ae09d06cf745ebeb3c414a83c94b58709e5/examples/helloworld/greeter_server/main.go

What version of Go are you using (go version)?

n/a

What operating system (Linux, Windows, …) and version?

n/a

What did you do?

I looked to see a good example for graceful shutdown

What did you expect to see?

The example ( https://github.com/grpc/grpc-go/blob/89737ae09d06cf745ebeb3c414a83c94b58709e5/examples/helloworld/greeter_server/main.go ) to show graceful shutdown on a signal

What did you see instead?

The following:

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

There is also nothing in the Go docs ( https://grpc.io/docs/languages/go/basics/#starting-the-server ) about draining requests / etc on shutdown or signal.

I think this should be in the docs/example as every app needs this. Would you accept a PR to add it?

[bkane-msft]

I think the correct code is:

	// graceful stop
	ch := make(chan os.Signal, 1)
	signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
	go func() {
		<-ch
		server.GracefulStop()
	}()

	// startup
	lis, err := net.Listen("tcp", ":27166")
	if err != nil {
		panic(fmt.Sprintf("failed to listen: %v", err))
	}
	slog.Info("server listening", "addr", lis.Addr())
	if err := server.Serve(lis); err != nil {
		panic(fmt.Sprintf("failed to serve: %v", err))
	}

but I'm new to gRPC and would like an authoritative example