platypush/platypush/plugins/mqtt.py
2020-01-22 18:34:28 +01:00

187 lines
7.3 KiB
Python

import io
import json
import os
import threading
from typing import Any, Optional, IO
from platypush.message import Message
from platypush.plugins import Plugin, action
class MqttPlugin(Plugin):
"""
This plugin allows you to send custom message to a message queue compatible
with the MQTT protocol, see http://mqtt.org/
Requires:
* **paho-mqtt** (``pip install paho-mqtt``)
"""
def __init__(self, host=None, port=1883, tls_cafile=None,
tls_certfile=None, tls_keyfile=None,
tls_version=None, tls_ciphers=None, username=None,
password=None, **kwargs):
"""
:param host: If set, MQTT messages will by default routed to this host unless overridden in `send_message` (default: None)
:type host: str
:param port: If a default host is set, specify the listen port (default: 1883)
:type port: int
:param tls_cafile: If a default host is set and requires TLS/SSL, specify the certificate authority file (default: None)
:type tls_cafile: str
:param tls_certfile: If a default host is set and requires TLS/SSL, specify the certificate file (default: None)
:type tls_certfile: str
:param tls_keyfile: If a default host is set and requires TLS/SSL, specify the key file (default: None)
:type tls_keyfile: str
:param tls_version: If a default host is set and requires TLS/SSL, specify the minimum TLS supported version (default: None)
:type tls_version: str
:param tls_ciphers: If a default host is set and requires TLS/SSL, specify the supported ciphers (default: None)
:type tls_ciphers: str
:param username: If a default host is set and requires user authentication, specify the username ciphers (default: None)
:type username: str
:param password: If a default host is set and requires user authentication, specify the password ciphers (default: None)
:type password: str
"""
super().__init__(**kwargs)
self.host = host
self.port = port
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
@action
def publish(self, topic: str, msg: Any, host: Optional[str] = None, port: int = 1883,
reply_topic: Optional[str] = None, timeout: int = 60,
tls_cafile: Optional[str] = None, tls_certfile: Optional[str] = None,
tls_keyfile: Optional[str] = None, tls_version: Optional[str] = None,
tls_ciphers: Optional[str] = None, username: Optional[str] = None,
password: Optional[str] = None):
"""
Sends a message to a topic.
:param topic: Topic/channel where the message will be delivered
:param msg: Message to be sent. It can be a list, a dict, or a Message object.
:param host: MQTT broker hostname/IP.
:param port: MQTT broker port (default: 1883).
:param reply_topic: If a ``reply_topic`` is specified, then the action will wait for a response on this topic.
:param timeout: If ``reply_topic`` is set, use this parameter to specify the maximum amount of time to
wait for a response (default: 60 seconds).
: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).
:param tls_certfile: If TLS/SSL is enabled on the MQTT server and a client certificate it required, specify it
here (default: None).
:param tls_keyfile: If TLS/SSL is enabled on the MQTT server and a client certificate key it required, specify
it here (default: None).
:param tls_version: If TLS/SSL is enabled on the MQTT server and it requires a certain TLS version, specify it
here (default: None).
: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).
:param username: Specify it if the MQTT server requires authentication (default: None).
:param password: Specify it if the MQTT server requires authentication (default: None).
"""
from paho.mqtt.client import Client
if not host and not self.host:
raise RuntimeError('No host specified and no default host configured')
if not host:
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
username = self.username
password = self.password
client = Client()
if username and password:
client.username_pw_set(username, password)
if tls_cafile:
client.tls_set(ca_certs=tls_cafile, certfile=tls_certfile, keyfile=tls_keyfile, tls_version=tls_version,
ciphers=tls_ciphers)
# Try to parse it as a platypush message or dump it to JSON from a dict/list
if isinstance(msg, dict) or isinstance(msg, list):
msg = json.dumps(msg)
# noinspection PyBroadException
try:
msg = Message.build(json.loads(msg))
except:
pass
client.connect(host, port, keepalive=timeout)
response_buffer = io.BytesIO()
try:
response_received = threading.Event()
if reply_topic:
client.on_message = self._response_callback(reply_topic=reply_topic,
event=response_received,
buffer=response_buffer)
client.subscribe(reply_topic)
client.publish(topic, str(msg))
if not reply_topic:
return
client.loop_start()
ok = response_received.wait(timeout=timeout)
if not ok:
raise TimeoutError('Response timed out')
return response_buffer.getvalue()
finally:
response_buffer.close()
# noinspection PyBroadException
try:
client.loop_stop()
except:
pass
client.disconnect()
@staticmethod
def _response_callback(reply_topic: str, event: threading.Event, buffer: IO[bytes]):
def on_message(client, _, msg):
if msg.topic != reply_topic:
return
buffer.write(msg.payload)
client.loop_stop()
event.set()
return on_message
@action
def send_message(self, *args, **kwargs):
"""
Alias for :meth:`platypush.plugins.mqtt.MqttPlugin.publish`.
"""
return self.publish(*args, **kwargs)
# vim:sw=4:ts=4:et: