Cherrypy MQTT HBMQTT plugin

hbmqttcherrypy.py

#https://stackoverflow.com/questions/26270681/can-an-asyncio-event-loop-run-in-the-background-without-suspending-the-python-in

import asyncio
import threading
import cherrypy
from cherrypy.process import plugins
from hbmqtt.client import MQTTClient, ClientException
from hbmqtt.mqtt.constants import QOS_1, QOS_2


class MQTTrepub(plugins.SimplePlugin):
    """
    Plugin that listens to MQTT topics (HBMQTT) and publishes the payload
    'unmodified' to a channel on the CherryPy bus. The cherrypy channel name
    is the same as the MQTT topic
    
    Requires HBMQTT
    """
    
    thread = None
    
    def __init__(self, bus, broker, subscriptionlist):
        plugins.SimplePlugin.__init__(self, bus)
        self.broker = broker
        self.subscriptionlist = subscriptionlist
        self.unsubscriptionlist = [item[0] for item in subscriptionlist]
        self.loop = asyncio.get_event_loop()
        self.C = MQTTClient(client_id = "cherrypy")
        self.running_flag = True
        cherrypy.engine.subscribe("stop", self.flag_setter)

    def flag_setter(self):
        self.running_flag = False

    @asyncio.coroutine
    def cherrymqtt(self, broker, subscriptionlist):
        yield from self.C.connect(broker)
        yield from self.C.subscribe(subscriptionlist)        
        try:
            while self.running_flag == True:
                message = yield from self.C.deliver_message()
                packet = message.publish_packet
                #print(packet)
                cherrypy.engine.publish(
                    packet.variable_header.topic_name, [
                        packet.variable_header.topic_name,
                        packet.protocol_ts, packet.payload.data
                    ]
                )
            yield from self.C.unsubscribe(self.unsubscriptionlist)
            yield from self.C.disconnect()
            self.loop.call_soon_threadsafe(self.loop.stop)
            self.stop()   
        except ClientException as ce:
            print("Client exception: %s" % ce)


    def start(self):
        if not self.thread:
            self.bus.log('Starting up hbmqttcherrypy')
            self.thread = threading.Thread(target=self.run).start()


    def stop(self):       
        self.bus.log('Shut down hbmqttcherrypy')


    def run(self):
        asyncio.set_event_loop(self.loop)
        self.loop.run_until_complete(self.cherrymqtt(self.broker, self.subscriptionlist))
        

#broker = 'mqtt://localhost/'
#subscriptionlist = [('some/topic/string/temperatures', QOS_1),]
#MQTTrepub(cherrypy.engine, broker, subscriptionlist).subscribe()

info.txt

Work in progress.
A, probably crude, attempt to push MQTT topics & data onto the cherrypy bus, using a HBMQTT client as cherrypy plug in.

Hi... I'm having trouble understanding how this works.

I have an existing cherrypy server running and would like to incorporate your code into it so that it can push and pull mqtt messages.

Hoping you could give a bit more direction on how to incorporate it into existing cherrpy code.

===================================

Figured it out. For starters I needed to upgrade py to 3.5!
You also needed to subscribe to the topic, otherwise your publish doesn't seem to go anywhere.
And, finally... when it quits it doesn't terminate the thread.

Thanks for posting this though, it was the only example I could find anywhere!