86 lines
2.5 KiB
Python
86 lines
2.5 KiB
Python
import json
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import threading
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import paho.mqtt.client as mqtt
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import paho.mqtt.publish as publisher
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from platypush.backend import Backend
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from platypush.message import Message
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from platypush.message.request import Request
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class MqttBackend(Backend):
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"""
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Backend that reads messages from a configured MQTT topic (default:
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``platypush_bus_mq/<device_id>``) and posts them to the application bus.
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Requires:
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* **paho-mqtt** (``pip install paho-mqtt``)
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"""
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def __init__(self, host, port=1883, topic='platypush_bus_mq', *args, **kwargs):
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"""
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:param host: MQTT broker host
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:type host: str
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:param port: MQTT broker port (default: 1883)
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:type port: int
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:param topic: Topic to read messages from (default: ``platypush_bus_mq/<device_id>``)
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:type topic: str
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"""
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super().__init__(*args, **kwargs)
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self.host = host
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self.port = port
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self.topic = '{}/{}'.format(topic, self.device_id)
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def send_message(self, msg):
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try:
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msg = Message.build(json.loads(msg))
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except:
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pass
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publisher.single(self.topic, str(msg), hostname=self.host, port=self.port)
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def run(self):
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def on_connect(client, userdata, flags, rc):
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client.subscribe(self.topic)
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def on_message(client, userdata, msg):
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def response_thread(msg):
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response = self.get_message_response(msg)
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response_topic = '{}/responses/{}'.format(self.topic, msg.id)
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self.logger.info('Processing response on the MQTT topic {}: {}'.
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format(response_topic, response))
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publisher.single(response_topic, str(response),
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hostname=self.host, port=self.port)
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msg = msg.payload.decode('utf-8')
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try: msg = Message.build(json.loads(msg))
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except: pass
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self.logger.info('Received message on the MQTT backend: {}'.format(msg))
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self.on_message(msg)
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if isinstance(msg, Request):
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threading.Thread(target=response_thread, args=(msg,)).start()
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super().run()
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client = mqtt.Client()
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client.on_connect = on_connect
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client.on_message = on_message
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client.connect(self.host, self.port, 60)
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self.logger.info('Initialized MQTT backend on host {}:{}, topic {}'.
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format(self.host, self.port, self.topic))
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client.loop_forever()
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# vim:sw=4:ts=4:et:
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