platypush/platypush/backend/mqtt.py

147 lines
5.3 KiB
Python

import json
import os
import threading
import paho.mqtt.client as mqtt
import paho.mqtt.publish as publisher
from platypush.backend import Backend
from platypush.context import get_plugin
from platypush.message import Message
from platypush.message.request import Request
class MqttBackend(Backend):
"""
Backend that reads messages from a configured MQTT topic (default:
``platypush_bus_mq/<device_id>``) and posts them to the application bus.
Requires:
* **paho-mqtt** (``pip install paho-mqtt``)
"""
def __init__(self, host, port=1883, topic='platypush_bus_mq', tls_cafile=None,
tls_certfile=None, tls_keyfile=None,
tls_version=None, tls_ciphers=None, username=None,
password=None, *args, **kwargs):
"""
:param host: MQTT broker host
:type host: str
:param port: MQTT broker port (default: 1883)
:type port: int
:param topic: Topic to read messages from (default: ``platypush_bus_mq/<device_id>``)
:type topic: str
:param tls_cafile: If TLS/SSL is enabled on the MQTT server and the certificate requires a certificate authority to authenticate it, `ssl_cafile` will point to the provided ca.crt file (default: None)
:type tls_cafile: str
:param tls_certfile: If TLS/SSL is enabled on the MQTT server and a client certificate it required, specify it here (default: None)
:type tls_certfile: str
:param tls_keyfile: If TLS/SSL is enabled on the MQTT server and a client certificate key it required, specify it here (default: None)
:type tls_keyfile: str
:param tls_version: If TLS/SSL is enabled on the MQTT server and it requires a certain TLS version, specify it here (default: None)
:type tls_version: str
:param tls_ciphers: If TLS/SSL is enabled on the MQTT server and an explicit list of supported ciphers is required, specify it here (default: None)
:type tls_ciphers: str
:param username: Specify it if the MQTT server requires authentication (default: None)
:type username: str
:param password: Specify it if the MQTT server requires authentication (default: None)
:type password: str
"""
super().__init__(*args, **kwargs)
self.host = host
self.port = port
self.topic = '{}/{}'.format(topic, self.device_id)
self.username = username
self.password = password
self.tls_cafile = os.path.abspath(os.path.expanduser(tls_cafile)) \
if tls_cafile else None
self.tls_certfile = os.path.abspath(os.path.expanduser(tls_certfile)) \
if tls_certfile else None
self.tls_keyfile = os.path.abspath(os.path.expanduser(tls_keyfile)) \
if tls_keyfile else None
self.tls_version = tls_version
self.tls_ciphers = tls_ciphers
def send_message(self, msg):
try:
client = get_plugin('mqtt')
client.send_message(topic=self.topic, msg=msg, host=self.host,
port=self.port, username=self.username,
password=self.password, tls_cafile=self.tls_cafile,
tls_certfile=self.tls_certfile,
tls_keyfile=self.tls_keyfile,
tls_version=self.tls_version,
tls_ciphers=self.tls_ciphers)
except Exception as e:
self.logger.exception(e)
def run(self):
def on_connect(client, userdata, flags, rc):
client.subscribe(self.topic)
def on_message(client, userdata, msg):
def response_thread(msg):
response = self.get_message_response(msg)
if not response:
return
response_topic = '{}/responses/{}'.format(self.topic, msg.id)
self.logger.info('Processing response on the MQTT topic {}: {}'.
format(response_topic, response))
self.send_message(response)
msg = msg.payload.decode('utf-8')
try: msg = Message.build(json.loads(msg))
except: pass
if not msg: return
self.logger.info('Received message on the MQTT backend: {}'.format(msg))
try:
self.on_message(msg)
except Exception as e:
self.logger.exception(e)
return
if isinstance(msg, Request):
threading.Thread(target=response_thread, args=(msg,)).start()
super().run()
client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
if self.username and self.password:
client.username_pw_set(self.username, self.password)
if self.tls_cafile:
client.tls_set(ca_certs=self.tls_cafile, certfile=self.tls_certfile,
keyfile=self.tls_keyfile, tls_version=self.tls_version,
ciphers=self.tls_ciphers)
client.connect(self.host, self.port, 60)
self.logger.info('Initialized MQTT backend on host {}:{}, topic {}'.
format(self.host, self.port, self.topic))
client.loop_forever()
# vim:sw=4:ts=4:et: