// character limit on client_id according to
	// MQTT spec.
	clientID := fmt.Sprintf("%x", time.Now().UnixNano())

	options := mqtt.NewClientOptions().
		SetClientID(clientID).
		SetCleanSession(true).
		SetUsername(args.User).
		SetPassword(args.Password).
		SetMaxReconnectInterval(args.MaxReconnectInterval).
		SetKeepAlive(args.KeepAlive).
		SetTLSConfig(&tls.Config{RootCAs: args.RootCAs}).