mqtt_logger.py

"""
MIT License
Copyright (c) 2016 Pipat Methavanitpong
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

import logging
from paho.mqtt.client import MQTTv31
import paho.mqtt.publish as publish


class MQTTHandler(logging.Handler):
    """
    A handler class which writes logging records, appropriately formatted,
    to a MQTT server to a topic.
    """
    def __init__(self, hostname, topic, qos=0, retain=False,
                 port=1883, client_id='', keepalive=60, will=None, auth=None,
                 tls=None, protocol=MQTTv31, transport='tcp'):
        logging.Handler.__init__(self)
        self.topic = topic
        self.qos = qos
        self.retain = retain
        self.hostname = hostname
        self.port = port
        self.client_id = client_id
        self.keepalive = keepalive
        self.will = will
        self.auth = auth
        self.tls = tls
        self.protocol = protocol
        self.transport = transport

    def emit(self, record):
        """
        Publish a single formatted logging record to a broker, then disconnect
        cleanly.
        """
        msg = self.format(record)
        try:
            publish.single(self.topic, msg, self.qos, self.retain,
                       hostname=self.hostname, port=self.port,
                       client_id=self.client_id, keepalive=self.keepalive,
                       will=self.will, auth=self.auth, tls=self.tls,
                       protocol=self.protocol, transport=self.transport)
        except Exception as e:
            pass # TODO log in exec ?