func writeToServer(conn net.Conn, ctx context.Context, wg *sync.WaitGroup) {
 // defer wg.Done()

 scanner := bufio.NewScanner(os.Stdin)

 for {
  select {
  case <-ctx.Done():
   fmt.Println("done recevied in client goroutine")
   return
  default:
   if !scanner.Scan() {
    fmt.Println("return in client gor")
    return
   }

   cmd := scanner.Text()

   conn.Write([]byte(fmt.Sprintf("%s\n", cmd)))
  }
 }

 log.Println("Reading from os.stdin is finished")
}

func gracefulShutdown(conn net.Conn, quitCh <-chan os.Signal, cancel func()) {
 defer cancel()

 <-quitCh

 log.Println("Connection is closing...")

 err := conn.Close()
 if err != nil {
  log.Fatalf("Cannot close connection: %v", err)
 }

 log.Println("Connection is closed")
}