mqtt_app.py 文件源码

def start_mqtt():
    global mqtt_client
    try:
        log.debug('Start MQTT Client')

        mqtt_client = mqtt.Client(client_id=settings.MQTT_CLIENT_ID)

        if settings.MQTT_LOGGING:
            # Add MQTT logging to the app logs
            mqtt_client.enable_logger(AppLogger.logger)
        else:
            mqtt_client.disable_logger()

        # Assign callback functions
        mqtt_client.on_connect = on_connect
        mqtt_client.on_message = on_message
        mqtt_client.on_publish = on_publish
        mqtt_client.on_subscribe = on_subscribe

        # Set a Will to be sent by the broker in case the client disconnects unexpectedly.
        # QOS 2: The broker will deliver the message exactly once by using a four step handshake.
        mqtt_client.will_set('/will/oops', payload='{} has vanished!'.format(settings.MQTT_CLIENT_ID), qos=2)

        connack_code = mqtt_client.connect(settings.MQTT_SERVER, settings.MQTT_PORT)
        log.info('MQTT connect reply to {}, {}: {}'.format(settings.MQTT_SERVER, settings.MQTT_PORT,
                                                           mqtt.connack_string(connack_code)))
        # Blocking call that processes network traffic, dispatches callbacks and
        # handles reconnecting.
        mqtt_client.loop_forever()

    except Exception as ex:
        log.error('Exception in start_mqtt()! exception: {}'.format(ex))
        raise