Source code for festivalgrid.device_templates.mqtt_device

import uuid
import socket

from django.conf import settings
import paho.mqtt.client as paho

from .device import DeviceTemplate


def init_mqtt(client_id=None, on_message=False, on_connect=False, on_disconnect=False):
    """This will open a connection to the mqtt broker and register any callbacks you pass in as parameters.

    :param client_id: The name this connection should register as with the broker.
    :type client_id: str.
    :param on_message: Callback function that gets called when a new message is received.
    :type on_message: function.
    :param on_connect: Callback function that gets called when the connection to the broker is successful.
    :type on_connect: function.
    :param on_disconnect: Callback function that gets called when the broker disconnects.
    :type on_disconnect: function.
    :returns:  paho.Client -- the paho Client object instance

    """
    if client_id is None:
        client_id = 'festivalgrid-%s' % uuid.uuid4()

    client = paho.Client(client_id, clean_session=False)

    if on_message:
        client.on_message = on_message
    if on_connect:
        client.on_connect = on_connect
    if on_disconnect:
        client.on_disconnect = on_disconnect

    if settings.MQTT_USERNAME:
        client.username_pw_set(settings.MQTT_USERNAME, settings.MQTT_PASSWORD)
    if settings.MQTT_TLS:
        client.tls_set()

    # wait for mqtt host
    socket.socket(socket.AF_INET, socket.SOCK_STREAM).connect_ex((settings.MQTT_HOST, int(settings.MQTT_PORT)))

    client.connect(settings.MQTT_HOST, settings.MQTT_PORT, 5)
    return client


class MQTTDevice(DeviceTemplate):
    """The base class for MQTT based devices.

        .. note::

            :class:`.Tasmota` is a good reference for implementing new MQTT based device templates.
        """

    _client = None

    def send_mqtt_message(self, topic, message):
        """Use this to send a message to the mqtt broker.

        :param topic: The topic this message should be published under.
        :type topic: str.
        :param message: The message that should be published.
        :type message: str.

        """
        if not self._client:
            self._client = init_mqtt('festivalgrid-device-template-%d' % self.device.pk)
        topic = "festivalgrid/" + self.device.mqtt_topic + "/" + topic
        self._client.publish(topic, message)

    def notify_setup_change(self, model):
        """Pings both the worker and mqtt_broker services that they should reload the setup."""
        self.send_mqtt_message("setup_changed", model)