base.py

from paho.mqtt import client as mqtt
import ConfigParser
import logging
import logging.handlers
import socket
import time
logger = logging.getLogger('BeaconReport')
#logger.setLevel(logging.DEBUG)

handler = logging.handlers.SysLogHandler(address='/dev/log')
logger.addHandler(handler)

MAX_RECONNECT_WAIT = 300  # seconds


class BaseMQTTClient(object):
    """BeaconReport class"""
    def __init__(self, config_file='config'):
        config_v = self.parse_config(config_file)
        self.url = config_v.get('url')
        self.port = config_v.get('port')
        self.keepalive = config_v.get('keepalive')
        self.client_id = config_v.get('client_id')
        self.username = config_v.get('username')
        self.password = config_v.get('password')
        self.certificate = config_v.get('certificate')
        self.client_key = config_v.get('client_key')
        self.client_cert = config_v.get('client_cert')
        self.mqtt_protocol = config_v.get('mqtt_protocol')
        self.topic_id = config_v.get('topic_id')
        self.mqtt_client = self.init_mqtt()

    def parse_config(self, config_file):
        """Read config file"""
        ret = {}
        config = ConfigParser.ConfigParser()
        config.read(config_file)
        ret["url"] = config.get('MQTT', 'url')
        ret["port"] = int(config.get('MQTT', 'port'))
        ret["keepalive"] = int(config.get('MQTT', 'keepalive'))
        ret["client_id"] = config.get('MQTT', 'client_id')
        ret["username"] = config.get('MQTT', 'username')
        ret["password"] = config.get('MQTT', 'password')
        certificate = config.get('MQTT', 'certificate')
        client_cert = config.get('MQTT', 'client_cert')
        client_key = config.get('MQTT', 'client_key')
        ret["certificate"] = certificate if certificate else None
        ret["client_key"] = client_key if client_key else None
        ret["client_cert"] = client_cert if client_cert else None
        ret["mqtt_protocol"] = config.get('MQTT', 'protocol')
        ret["topic_id"] = config.get('MQTT', 'topic_id')
        return ret

    def _on_disconnect(self, client, userdata, rc):
        """Disconnected callback."""
        logger.info('Disconnected from the MQTT server.')
        # When disconnected because of calling disconnect()
        if rc == 0:
            return

        tries = 0
        wait_time = 0

        while True:
            try:
                if client.reconnect() == 0:
                    logger.info('Reconnected to the MQTT server.')
                    break
            except socket.error:
                pass

            wait_time = min(2**tries, MAX_RECONNECT_WAIT)
            # It is ok to sleep here as we are in the MQTT thread.
            time.sleep(wait_time)
            tries += 1

    def init_mqtt(self):
        """Init MQTT connection"""
        proto = mqtt.MQTTv311
        if self.mqtt_protocol == "3.1":
            proto = mqtt.MQTTv31

        if not self.client_id:
            client = mqtt.Client(protocol=proto)
        else:
            client = mqtt.Client(self.client_id, protocol=proto)

        if self.username is not None:
            client.username_pw_set(self.username, self.password)

        if self.certificate is not None:
            client.tls_set(self.certificate,
                           certfile=self.client_cert,
                           keyfile=self.client_key)

        client.on_disconnect = self._on_disconnect

        try:
            client.connect(self.url, self.port, self.keepalive)
            logger.info('Connected to the MQTT server.')
            client.loop_start()
            return client
        except Exception, e:
            print(e)
            return None