├── examples ├── mysite │ ├── chat │ │ ├── __init__.py │ │ ├── routing.py │ │ ├── urls.py │ │ ├── views.py │ │ ├── templates │ │ │ └── chat │ │ │ │ ├── index.html │ │ │ │ └── room.html │ │ └── consumers.py │ ├── mysite │ │ ├── __init__.py │ │ ├── urls.py │ │ ├── wsgi.py │ │ ├── asgi.py │ │ └── settings.py │ └── manage.py └── README.md ├── .gitignore ├── setup.py ├── chanmqttproxy ├── __init__.py ├── mqttconsumer.py └── channelsmqttproxy.py ├── pyproject.toml ├── setup.cfg ├── README.md └── LICENSE /examples/mysite/chat/__init__.py: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /examples/mysite/mysite/__init__.py: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | __pycache__/ 2 | *.egg-info/ 3 | dist/ 4 | db.sqlite3 5 | -------------------------------------------------------------------------------- /setup.py: -------------------------------------------------------------------------------- 1 | import os.path 2 | import re 3 | from setuptools import setup 4 | 5 | setup() 6 | -------------------------------------------------------------------------------- /chanmqttproxy/__init__.py: -------------------------------------------------------------------------------- 1 | from .channelsmqttproxy import ChannelsMQTTProxy 2 | from .mqttconsumer import MqttConsumer 3 | -------------------------------------------------------------------------------- /pyproject.toml: -------------------------------------------------------------------------------- 1 | [build-system] 2 | requires = [ 3 | "setuptools >= 60", 4 | "wheel >= 0.29.0", 5 | ] 6 | build-backend = 'setuptools.build_meta' 7 | -------------------------------------------------------------------------------- /examples/mysite/chat/routing.py: -------------------------------------------------------------------------------- 1 | # chat/routing.py 2 | from django.urls import re_path 3 | 4 | from . import consumers 5 | 6 | websocket_urlpatterns = [ 7 | re_path(r'ws/chat/(?P\w+)/$', consumers.ChatConsumer.as_asgi()), 8 | ] 9 | -------------------------------------------------------------------------------- /examples/mysite/chat/urls.py: -------------------------------------------------------------------------------- 1 | # chat/urls.py 2 | from django.urls import path 3 | 4 | from . import views 5 | 6 | urlpatterns = [ 7 | path('', views.index, name='index'), 8 | path('/', views.room, name='room'), 9 | ] 10 | -------------------------------------------------------------------------------- /examples/README.md: -------------------------------------------------------------------------------- 1 | This is the tutorial code from 2 | https://channels.readthedocs.io/en/stable/tutorial/index.html up to 3 | part 3. 4 | 5 | It has been extended as per the main README. 6 | 7 | See the main README for instructions on running the example. 8 | 9 | 10 | -------------------------------------------------------------------------------- /examples/mysite/mysite/urls.py: -------------------------------------------------------------------------------- 1 | # mysite/urls.py 2 | from django.conf.urls import include 3 | from django.urls import path 4 | from django.contrib import admin 5 | 6 | urlpatterns = [ 7 | path('chat/', include('chat.urls')), 8 | path('admin/', admin.site.urls), 9 | ] 10 | -------------------------------------------------------------------------------- /examples/mysite/chat/views.py: -------------------------------------------------------------------------------- 1 | # chat/views.py 2 | from django.shortcuts import render 3 | 4 | def index(request): 5 | return render(request, 'chat/index.html', {}) 6 | 7 | def room(request, room_name): 8 | return render(request, 'chat/room.html', { 9 | 'room_name': room_name 10 | }) 11 | -------------------------------------------------------------------------------- /examples/mysite/mysite/wsgi.py: -------------------------------------------------------------------------------- 1 | """ 2 | WSGI config for mysite project. 3 | 4 | It exposes the WSGI callable as a module-level variable named ``application``. 5 | 6 | For more information on this file, see 7 | https://docs.djangoproject.com/en/3.1/howto/deployment/wsgi/ 8 | """ 9 | 10 | import os 11 | 12 | from django.core.wsgi import get_wsgi_application 13 | 14 | os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings') 15 | 16 | application = get_wsgi_application() 17 | -------------------------------------------------------------------------------- /examples/mysite/mysite/asgi.py: -------------------------------------------------------------------------------- 1 | # mysite/asgi.py 2 | import os 3 | 4 | from channels.auth import AuthMiddlewareStack 5 | from channels.routing import ChannelNameRouter, ProtocolTypeRouter, URLRouter 6 | from django.core.asgi import get_asgi_application 7 | import chat.routing 8 | from chanmqttproxy import MqttConsumer 9 | 10 | os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mysite.settings") 11 | 12 | application = ProtocolTypeRouter({ 13 | "channel": ChannelNameRouter({ 14 | "mqtt": MqttConsumer.as_asgi() 15 | }), 16 | "http": get_asgi_application(), 17 | "websocket": AuthMiddlewareStack( 18 | URLRouter( 19 | chat.routing.websocket_urlpatterns 20 | ) 21 | ), 22 | }) 23 | -------------------------------------------------------------------------------- /examples/mysite/manage.py: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env python 2 | """Django's command-line utility for administrative tasks.""" 3 | import os 4 | import sys 5 | 6 | 7 | def main(): 8 | """Run administrative tasks.""" 9 | os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'mysite.settings') 10 | try: 11 | from django.core.management import execute_from_command_line 12 | except ImportError as exc: 13 | raise ImportError( 14 | "Couldn't import Django. Are you sure it's installed and " 15 | "available on your PYTHONPATH environment variable? Did you " 16 | "forget to activate a virtual environment?" 17 | ) from exc 18 | execute_from_command_line(sys.argv) 19 | 20 | 21 | if __name__ == '__main__': 22 | main() 23 | -------------------------------------------------------------------------------- /examples/mysite/chat/templates/chat/index.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | Chat Rooms 7 | 8 | 9 | What chat room would you like to enter?
10 |
11 | 12 | 13 | 26 | 27 | 28 | -------------------------------------------------------------------------------- /setup.cfg: -------------------------------------------------------------------------------- 1 | [metadata] 2 | name = chanmqttproxy 3 | version = 0.2 4 | author = David Greaves 5 | author_email = david@dgreaves.com 6 | url = https://github.com/lbt/channels-mqtt-proxy 7 | description = Channels 4 Worker providing async (qmqtt) MQTT proxy 8 | long_description = file: README.md 9 | long_description_content_type = text/markdown 10 | license = GPLv3+ 11 | classifiers = 12 | Development Status :: 4 - Beta 13 | Environment :: Web Environment 14 | License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+) 15 | Framework :: Django 16 | Operating System :: OS Independent 17 | Programming Language :: Python 18 | Programming Language :: Python :: 3 19 | Programming Language :: Python :: 3.7 20 | [options] 21 | packages = chanmqttproxy 22 | install_requires = 23 | gmqtt 24 | asgiref >= 3.3.4 25 | Django >= 3.1.3 26 | channels 27 | 28 | [options.extras_require] 29 | examples = 30 | Django >= 4.0.0 31 | channels >= 4.0.0 32 | channels_redis 33 | daphne >= 4.0.0 34 | -------------------------------------------------------------------------------- /examples/mysite/chat/templates/chat/room.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | Chat Room 7 | 8 | 9 |
10 |
11 | 12 | {{ room_name|json_script:"room-name" }} 13 | 49 | 50 | 51 | -------------------------------------------------------------------------------- /chanmqttproxy/mqttconsumer.py: -------------------------------------------------------------------------------- 1 | import asyncio 2 | import logging 3 | import sys 4 | from channels.consumer import AsyncConsumer 5 | from channels.exceptions import StopConsumer 6 | from channels.layers import get_channel_layer 7 | from django.conf import settings 8 | 9 | from .channelsmqttproxy import ChannelsMQTTProxy 10 | 11 | LOGGER = logging.getLogger(__name__) 12 | 13 | 14 | class MqttConsumer(AsyncConsumer): 15 | """The MqttConsumer is run as a channels worker. It starts an MQTT 16 | client and handles subscription and message distribution via 17 | Channels messages. 18 | """ 19 | 20 | def __init__(self): 21 | super().__init__() 22 | self.mqttproxy = ChannelsMQTTProxy(get_channel_layer(), 23 | settings) 24 | self.task = asyncio.create_task(self.mqttproxy.run()) 25 | self.task.add_done_callback(self.finish) 26 | 27 | def finish(self, task): 28 | # For some reason the Channels worker doesn't seem to exit 29 | # if there's a task with a loop signal handler 30 | sys.exit(0) 31 | 32 | async def mqtt_subscribe(self, event): 33 | """This is the mqtt.subscribe channel message handler. It subscribes 34 | a channel group to a topic. All messages received for that 35 | topic will be sent to all members of the group using 36 | 'mqtt.message'. Multiple subscriptions are allowed. The topic 37 | uses MQTT wildcard syntax. The same topic may be subscibed by 38 | multiple channel groups 39 | 40 | """ 41 | topic = event['topic'] 42 | group = event['group'] 43 | LOGGER.debug(f"subscribe to {topic} for {group}") 44 | await self.mqttproxy.connected.wait() 45 | self.mqttproxy.subscribe(topic, group) 46 | 47 | async def mqtt_publish(self, event): 48 | """The event contains a publish dict which is used by the mqtt client. 49 | The values : topic, payload, qos & retain may be specified. 50 | """ 51 | LOGGER.debug(event) 52 | publish = event['publish'] 53 | # do something with topic and payload 54 | LOGGER.debug(f"MQTT publish ({publish})") 55 | await self.mqttproxy.connected.wait() 56 | self.mqttproxy.publish(**publish) 57 | -------------------------------------------------------------------------------- /examples/mysite/chat/consumers.py: -------------------------------------------------------------------------------- 1 | # chat/consumers.py 2 | import json 3 | import logging 4 | from channels.generic.websocket import AsyncWebsocketConsumer 5 | 6 | LOGGER = logging.getLogger(__name__) 7 | 8 | class ChatConsumer(AsyncWebsocketConsumer): 9 | async def connect(self): 10 | self.room_name = self.scope['url_route']['kwargs']['room_name'] 11 | self.room_group_name = 'chat_%s' % self.room_name 12 | 13 | # Join room group 14 | await self.channel_layer.group_add( 15 | self.room_group_name, 16 | self.channel_name 17 | ) 18 | # Join mqtt group 19 | await self.channel_layer.group_add( 20 | "mqttgroup", 21 | self.channel_name 22 | ) 23 | # Ensure MQTT messages come to the room 24 | # This simplistic approach subscribes the room every 25 | # time a websocket connects but that's OK 26 | await self.channel_layer.send( 27 | "mqtt", 28 | { 29 | "type": "mqtt_subscribe", 30 | "topic": f"chat/{self.room_name}", 31 | "group": "mqttgroup", 32 | }) 33 | await self.accept() 34 | 35 | async def disconnect(self, close_code): 36 | # Leave room group 37 | await self.channel_layer.group_discard( 38 | self.room_group_name, 39 | self.channel_name 40 | ) 41 | # Leave mqtt group 42 | await self.channel_layer.group_discard( 43 | "mqttgroup", 44 | self.channel_name 45 | ) 46 | 47 | # Receive message from WebSocket 48 | async def receive(self, text_data): 49 | text_data_json = json.loads(text_data) 50 | message = text_data_json['message'] 51 | 52 | # Send message to room group 53 | await self.channel_layer.group_send( 54 | self.room_group_name, 55 | { 56 | 'type': 'chat_message', 57 | 'message': message 58 | } 59 | ) 60 | # Publish on mqtt too 61 | await self.channel_layer.send( 62 | "mqtt", 63 | { 64 | "type": "mqtt_publish", 65 | "publish": { # These form the kwargs for mqtt.publish 66 | "topic": f"chat/{self.room_name}_out", 67 | "payload": message, 68 | "qos": 2, 69 | "retain": False, 70 | } 71 | }) 72 | 73 | # Receive message from room group 74 | async def chat_message(self, event): 75 | message = event['message'] 76 | 77 | # Send message to WebSocket 78 | await self.send(text_data=json.dumps({ 79 | 'message': message 80 | })) 81 | 82 | # Receive message from mqtt group and send to websocket 83 | async def mqtt_message(self, event): 84 | LOGGER.debug(f"Got mqtt event, send to websocket. Event: {event}") 85 | message = event['message'] 86 | payload = message["payload"] 87 | 88 | # Send message to WebSocket 89 | await self.send(text_data=json.dumps({ 90 | 'message': payload 91 | })) 92 | -------------------------------------------------------------------------------- /examples/mysite/mysite/settings.py: -------------------------------------------------------------------------------- 1 | """ 2 | Django settings for mysite project. 3 | 4 | Generated by 'django-admin startproject' using Django 3.1.3. 5 | 6 | For more information on this file, see 7 | https://docs.djangoproject.com/en/3.1/topics/settings/ 8 | 9 | For the full list of settings and their values, see 10 | https://docs.djangoproject.com/en/3.1/ref/settings/ 11 | """ 12 | 13 | from pathlib import Path 14 | 15 | # Build paths inside the project like this: BASE_DIR / 'subdir'. 16 | BASE_DIR = Path(__file__).resolve().parent.parent 17 | 18 | 19 | # Quick-start development settings - unsuitable for production 20 | # See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/ 21 | 22 | # SECURITY WARNING: keep the secret key used in production secret! 23 | SECRET_KEY = '%80*8!=b9%8x&28&g!)*(@)e3vi&@0%t-#q0ktrc=$vtij0ncy' 24 | 25 | # SECURITY WARNING: don't run with debug turned on in production! 26 | DEBUG = True 27 | 28 | ALLOWED_HOSTS = [] 29 | 30 | # Channels 31 | ASGI_APPLICATION = 'mysite.asgi.application' 32 | CHANNEL_LAYERS = { 33 | 'default': { 34 | 'BACKEND': 'channels_redis.core.RedisChannelLayer', 35 | 'CONFIG': { 36 | "hosts": [('127.0.0.1', 6379)], 37 | }, 38 | }, 39 | } 40 | # Local mqtt settings 41 | MQTT_HOST = "mqtt" 42 | MQTT_USER = "mqtt-test" 43 | MQTT_PASSWORD = "mqtt-test" 44 | #MQTT_VERSION = 311 # defaults to 50 45 | # Application definition 46 | 47 | INSTALLED_APPS = [ 48 | 'chat', 49 | 'daphne', 50 | 'channels', 51 | 'django.contrib.admin', 52 | 'django.contrib.auth', 53 | 'django.contrib.contenttypes', 54 | 'django.contrib.sessions', 55 | 'django.contrib.messages', 56 | 'django.contrib.staticfiles', 57 | ] 58 | 59 | MIDDLEWARE = [ 60 | 'django.middleware.security.SecurityMiddleware', 61 | 'django.contrib.sessions.middleware.SessionMiddleware', 62 | 'django.middleware.common.CommonMiddleware', 63 | 'django.middleware.csrf.CsrfViewMiddleware', 64 | 'django.contrib.auth.middleware.AuthenticationMiddleware', 65 | 'django.contrib.messages.middleware.MessageMiddleware', 66 | 'django.middleware.clickjacking.XFrameOptionsMiddleware', 67 | ] 68 | 69 | ROOT_URLCONF = 'mysite.urls' 70 | 71 | TEMPLATES = [ 72 | { 73 | 'BACKEND': 'django.template.backends.django.DjangoTemplates', 74 | 'DIRS': [], 75 | 'APP_DIRS': True, 76 | 'OPTIONS': { 77 | 'context_processors': [ 78 | 'django.template.context_processors.debug', 79 | 'django.template.context_processors.request', 80 | 'django.contrib.auth.context_processors.auth', 81 | 'django.contrib.messages.context_processors.messages', 82 | ], 83 | }, 84 | }, 85 | ] 86 | 87 | WSGI_APPLICATION = 'mysite.wsgi.application' 88 | 89 | 90 | # Database 91 | # https://docs.djangoproject.com/en/3.1/ref/settings/#databases 92 | 93 | DATABASES = { 94 | 'default': { 95 | 'ENGINE': 'django.db.backends.sqlite3', 96 | 'NAME': BASE_DIR / 'db.sqlite3', 97 | } 98 | } 99 | 100 | 101 | # Password validation 102 | # https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators 103 | 104 | AUTH_PASSWORD_VALIDATORS = [ 105 | { 106 | 'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator', 107 | }, 108 | { 109 | 'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator', 110 | }, 111 | { 112 | 'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator', 113 | }, 114 | { 115 | 'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator', 116 | }, 117 | ] 118 | 119 | 120 | # Internationalization 121 | # https://docs.djangoproject.com/en/3.1/topics/i18n/ 122 | 123 | LANGUAGE_CODE = 'en-us' 124 | 125 | TIME_ZONE = 'UTC' 126 | 127 | USE_I18N = True 128 | 129 | USE_L10N = True 130 | 131 | USE_TZ = True 132 | 133 | 134 | # Static files (CSS, JavaScript, Images) 135 | # https://docs.djangoproject.com/en/3.1/howto/static-files/ 136 | 137 | STATIC_URL = '/static/' 138 | import logging.config 139 | 140 | LOGGING_CONFIG = None 141 | 142 | logging.config.dictConfig({ 143 | 'version': 1, 144 | 'disable_existing_loggers': False, 145 | 'formatters': { 146 | 'console': { 147 | # exact format is not important, this is the minimum information 148 | 'format': '%(asctime)s %(name)-12s %(levelname)-8s %(message)s', 149 | }, 150 | }, 151 | 'handlers': { 152 | 'console': { 153 | 'class': 'logging.StreamHandler', 154 | 'formatter': 'console', 155 | }, 156 | }, 157 | 'loggers': { 158 | # root logger 159 | 'chanmqttproxy': { 160 | 'level': 'DEBUG', 161 | 'handlers': ['console'], 162 | }, 163 | 'mysite': { 164 | 'level': 'DEBUG', 165 | 'handlers': ['console'], 166 | }, 167 | 'chat': { 168 | 'level': 'DEBUG', 169 | 'handlers': ['console'], 170 | }, 171 | }, 172 | }) 173 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # channels-mqtt-proxy 2 | 3 | A Channels 3/4 compatible MQTT worker 4 | 5 | This worker is a standard Channels Consumer which contains a 6 | fully async MQTT server allowing channels messages to be used to 7 | publish, subscribe to and receive MQTT messages 8 | 9 | The proxy understands mqtt.subscribe and mqtt.publish so you can 10 | change the topics dynamically. 11 | 12 | When an MQTT subscribe is performed it is done on behalf of a channels 13 | group and all Channels Consumers in that group will receive mqtt 14 | messages as mqtt.message 15 | 16 | The overview is : 17 | 18 | MQTT <> Channels-MQTT-Proxy (in runworker) <> Redis/Channels-layer <> ASGI applications (in Daphne/runserver) <> Websockets/HTTP <> Browser 19 | 20 | 21 | ## Installation 22 | 23 | ```bash 24 | pip install chanmqttproxy 25 | ``` 26 | 27 | ## Usage 28 | 29 | In Channels the asgi application handles all types of connection 30 | routing. Websocket and http connections are listened for by a 31 | suitable server (eg daphne run by manage.py runserver) which will 32 | instantiate classes and run objects to handle them. The 'mqtt' 33 | Consumer does not accept incoming connections, just channel 34 | messages. So it must be started as a worker which handles the Channel 35 | messages; the MQTT client connection is then created inside the 36 | MqttConsumer worker when the first channel message is received. 37 | 38 | ## Setup 39 | 40 | The code may look familiar if you've used the Channels 41 | [Chat tutorial](https://channels.readthedocs.io/en/stable/tutorial/index.html) :) 42 | 43 | In fact it will add the ability to monitor the chat on the chat/ 44 | MQTT channel and messages sent to that channel will appear on all 45 | clients. 46 | 47 | 48 | In `site/asgi.py`: 49 | 50 | ```python 51 | from chanmqttproxy import MqttConsumer 52 | from channels.routing import ChannelNameRouter, ProtocolTypeRouter 53 | 54 | application = ProtocolTypeRouter({ 55 | "channel": ChannelNameRouter({ 56 | "mqtt": MqttConsumer.as_asgi() 57 | }), 58 | ... # rest of http/websocket routes 59 | }) 60 | ``` 61 | To define the MQTT broker, in `site/settings.py`: 62 | 63 | ```python 64 | # Local mqtt settings 65 | MQTT_HOST = "mqtt.example.com" 66 | MQTT_USER = "mqtt-test" 67 | MQTT_PASSWORD = "mqtt-test" 68 | MQTT_VERSION = 311 # defaults to 50 69 | ``` 70 | 71 | At this point you have a working async Channels/MQTT bridge 72 | 73 | To subscribe to a topic in your AsyncConsumer 74 | 75 | ```python 76 | async def connect(self): 77 | ... # existing group_add() calls 78 | 79 | # Join mqtt group 80 | await self.channel_layer.group_add( 81 | "mqttgroup", 82 | self.channel_name 83 | ) 84 | # Ensure MQTT messages come to the room 85 | # This simplistic approach subscribes the room every 86 | # time a websocket connects but that's OK 87 | await self.channel_layer.send( 88 | "mqtt", 89 | { 90 | "type": "mqtt_subscribe", 91 | "topic": f"chat/{self.room_name}", 92 | "group": "mqttgroup", 93 | }) 94 | 95 | await self.accept() # existing accept() call 96 | ``` 97 | To handle messages from a topic in your AsyncConsumer 98 | 99 | ```python 100 | # Receive message from mqtt group and send to websocket 101 | async def mqtt_message(self, event): 102 | message = event['message'] 103 | topic = messagep["topic"] 104 | payload = messagep["payload"] 105 | 106 | # Send message to WebSocket 107 | await self.send(text_data=json.dumps({ 108 | 'message': payload 109 | })) 110 | ``` 111 | To publish messages to a topic in your AsyncConsumer 112 | 113 | ```python 114 | # Receive message from WebSocket 115 | async def receive(self, text_data): 116 | 117 | ... # existing group_send etc 118 | 119 | # Publish on mqtt too 120 | await self.channel_layer.send( 121 | "mqtt", 122 | { 123 | "type": "mqtt_publish", 124 | "publish": { # These form the kwargs for mqtt.publish 125 | "topic": f"chat/{self.room_name}_out", 126 | "payload": message, 127 | "qos": 2, 128 | "retain": False, 129 | } 130 | }) 131 | ``` 132 | 133 | For debug logging I use this at the end of settings.py: 134 | 135 | ```python 136 | import logging.config 137 | 138 | LOGGING_CONFIG = None 139 | 140 | logging.config.dictConfig({ 141 | 'version': 1, 142 | 'disable_existing_loggers': False, 143 | 'formatters': { 144 | 'console': { 145 | # exact format is not important, this is the minimum information 146 | 'format': '%(asctime)s %(name)-12s %(levelname)-8s %(message)s', 147 | }, 148 | }, 149 | 'handlers': { 150 | 'console': { 151 | 'class': 'logging.StreamHandler', 152 | 'formatter': 'console', 153 | }, 154 | }, 155 | 'loggers': { 156 | # root logger 157 | 'chanmqttproxy': { 158 | 'level': 'DEBUG', 159 | 'handlers': ['console'], 160 | }, 161 | 'mysite': { 162 | 'level': 'DEBUG', 163 | 'handlers': ['console'], 164 | }, 165 | 'chat': { 166 | 'level': 'DEBUG', 167 | 'handlers': ['console'], 168 | }, 169 | }, 170 | }) 171 | ``` 172 | 173 | The complete code for the Channels Chat tutorial application (up to 174 | part 3) with the channels-mqtt-proxy additions is here: 175 | https://github.com/lbt/channels-mqtt-proxy/tree/main/examples 176 | 177 | ## Example Usage 178 | 179 | Create and activate a suitable venv. 180 | 181 | Enter the `examples/` directory. 182 | 183 | You'll need a Redis instance for Channels to work sensibly and an MQTT 184 | broker like mosquitto of course. 185 | 186 | Setup Django/channels etc in your venv by running: 187 | 188 | ``` 189 | pip install ..[examples] 190 | ``` 191 | 192 | Then edit `mysite/mysite/settings.py` to point to your mqtt server and run; 193 | 194 | 195 | ```python 196 | python3 mysite/manage.py migrate 197 | python3 mysite/manage.py runworker mqtt & 198 | python3 mysite/manage.py runserver 199 | ``` 200 | 201 | Navigate to http://127.0.0.1:8000/chat/ and use "lobby" for the room. 202 | 203 | Use your mqtt listener to listen to the topic `chat/lobby_out` and 204 | publish to the topic `chat/lobby` 205 | 206 | Notice that if we had just used chat/ for both topics then when 207 | the chat room sends a message and the proxy client publishes it to 208 | the MQTT topic the message would appear twice in the room. This is 209 | because even if you're the one that publishes a message, if you're 210 | subscribed to the topic, you will receive it too. 211 | 212 | If you make changes to the code note that the Channels runworker does 213 | not auto-reload and will still hold old subscribe/group information. 214 | 215 | 216 | # TODO/Issues 217 | 218 | ## Connect to MQTT at startup 219 | The MqttConsumer is only instantiated after the first message arrives 220 | rather than when the worker starts. This means it may not be connected 221 | so the await self.mqttproxy.connected.wait() is required on every 222 | subscribe/publish (which is not a lot of overhead but... 223 | 224 | ## Unsubscribing and no-more-clients 225 | It's not clear how to issue an unsubscribe or deal with all clients 226 | disconnecting. If this is done in the AsyncConsumer disconnect() then 227 | it needs a client-count which is probably unreliable. Currently MQTT 228 | messages will always be sent to the Channels group and it handles 229 | member timeout as per 230 | https://channels.readthedocs.io/en/stable/channel_layer_spec.html#capacity 231 | and 232 | https://channels.readthedocs.io/en/stable/channel_layer_spec.html#persistence 233 | 234 | ## retain'ed messages 235 | On initial subscribtion all retained messages are dropped. This is 236 | not ideal when retained messages are used to indicate 'last known 237 | state' for clients. 238 | 239 | However this is an MQTT concept and doesn't carry over to Channels 240 | unless we handle retention and continue to store messages for each 241 | Channel client that subscribes - and then somehow only send retained 242 | messages to that new client and not the existing clients who've seen 243 | them once.. 244 | 245 | Ideally there would be a mechanism for the app to pre-subscribe and 246 | send retained (and new) messages to code that could update the 247 | 'current state' model which would then be maintained and used to 248 | initialise new browser clients. 249 | 250 | ## MqttConsumer in worker doesn't exit 251 | There doesn't seem to be a way to tell the worker to exit on Ctrl-C if 252 | we trap it to clean up the MQTT connections. Also note that in some 253 | situations the Ctrl-C fails. Eg if the broker doesn't support V5.0 and 254 | fallback to V311 is underway. 255 | 256 | # Thanks 257 | Thanks to Gurtam for https://github.com/wialon/gmqtt which is a great asyncio 258 | MQTT client that I use extensively in my HA systems and integrate with PyQt too. 259 | 260 | The Channels tutorial was really helpful in understanding the concepts. 261 | 262 | Also to Xavier Lesa for https://github.com/xavierlesa/channels-asgi-mqtt which 263 | is based on the paho-mqtt synchronous library and inspired me to write this. 264 | -------------------------------------------------------------------------------- /chanmqttproxy/channelsmqttproxy.py: -------------------------------------------------------------------------------- 1 | import asyncio 2 | import functools 3 | import json 4 | import logging 5 | import os 6 | import signal 7 | import socket 8 | 9 | from gmqtt import Client as MQTTClient 10 | from gmqtt.mqtt.constants import MQTTv311, MQTTv50 11 | 12 | LOGGER = logging.getLogger(__name__) 13 | 14 | 15 | class ChannelsMQTTProxy: 16 | def __init__(self, channel_layer, settings): 17 | self.channel_layer = channel_layer 18 | 19 | # MQTTClient takes an identifier which is seen at the broker 20 | # Creating the client does not connect. 21 | self.mqtt = MQTTClient( 22 | f"ChannelsMQTTProxy@{socket.gethostname()}.{os.getpid()}") 23 | self.mqtt.set_auth_credentials(username=settings.MQTT_USER, 24 | password=settings.MQTT_PASSWORD) 25 | self.mqtt_host = settings.MQTT_HOST 26 | try: 27 | self.mqtt_version = settings.MQTT_VERSION 28 | except AttributeError: 29 | self.mqtt_version = 50 30 | # Hook up the callbacks and some lifecycle management events 31 | self.mqtt.on_connect = self._on_connect 32 | self.mqtt.on_disconnect = self._on_disconnect 33 | self.mqtt.on_message = self._on_subscribe 34 | self.mqtt.on_message = self._on_message 35 | self.stop_event = asyncio.Event() 36 | self.connected = asyncio.Event() 37 | 38 | try: 39 | self.mqtt_channel_name = settings.MQTT_CHANNEL_NAME 40 | except AttributeError: 41 | self.mqtt_channel_name = "mqtt" 42 | self.mqtt_channel_publish = f"{self.mqtt_channel_name}.publish" 43 | self.mqtt_channel_message = f"{self.mqtt_channel_name}.message" 44 | self.subscriptions = {} 45 | 46 | async def run(self): 47 | """This connects to the mqtt broker (retrying forever) and then waits 48 | for :func:`finish()` Once connected the underlying qmqtt 49 | client will re-connect if the connection is lost. 50 | """ 51 | loop = asyncio.get_event_loop() 52 | loop.add_signal_handler(signal.SIGINT, self.ask_exit) 53 | loop.add_signal_handler(signal.SIGTERM, self.ask_exit) 54 | await self.connect() 55 | await self.finish() 56 | 57 | async def connect(self): 58 | # Connect to the broker 59 | if self.mqtt_version == 311: 60 | version = MQTTv311 61 | else: 62 | version = MQTTv50 63 | 64 | while not self.mqtt.is_connected: 65 | try: 66 | await self.mqtt.connect(self.mqtt_host, version=version) 67 | except Exception as e: 68 | LOGGER.warn(f"Error trying to connect: {e}. Retrying.") 69 | await asyncio.sleep(1) 70 | self.connected.set() 71 | 72 | async def finish(self): 73 | # This will wait until the client is signalled 74 | LOGGER.debug("Waiting for stop event") 75 | await self.stop_event.wait() 76 | await self.mqtt.disconnect() 77 | LOGGER.debug("MQTT client disconnected") 78 | 79 | def _on_connect(self, _client, _flags, _rc, _properties): 80 | for s in self.subscriptions.keys(): 81 | LOGGER.debug(f"Re-subscribing to {s}") 82 | self.mqtt.subscribe(s) 83 | LOGGER.debug('Connected and subscribed') 84 | 85 | def _on_disconnect(self, _client, _packet, _exc=None): 86 | LOGGER.debug('Disconnected') 87 | 88 | async def _on_message(self, _client, topic, payload, qos, properties): 89 | LOGGER.debug(f"{topic} => '{payload}' props:{properties}") 90 | 91 | # Check properties for 'retain' (which in this context means 92 | # the message is being sent from retained backing store) and 93 | # drop those. 94 | # Eventually find a way to direct these to support code which can build 95 | # initial state and keep it up-to-date? This is linked to 96 | # connect-on-startup. 97 | if properties["retain"] == 1: 98 | LOGGER.debug(f"Dropping replayed retained message") 99 | return 100 | 101 | # Compose a Channel message 102 | payload = payload.decode("utf-8") 103 | try: 104 | payload = json.loads(payload) 105 | except: 106 | LOGGER.debug("Payload is not JSON - sending it raw") 107 | pass 108 | msg = { 109 | "topic": topic, 110 | "payload": payload, 111 | "qos": qos, 112 | } 113 | event = { 114 | "type": self.mqtt_channel_message, # default "mqtt.message" 115 | "message": msg 116 | } 117 | 118 | tasks = list() 119 | for grp in self.groups_matching_topic(topic): 120 | tasks.append(self.channel_layer.group_send(grp, event)) 121 | LOGGER.debug(f"Calling {grp} handler for {topic}") 122 | try: 123 | await asyncio.gather(*tasks) 124 | except Exception as e: 125 | LOGGER.error("Cannot send event: {event}") 126 | LOGGER.exception(e) 127 | 128 | def subscribe(self, topic, group): 129 | """Subscribes a group to an MQTT topic (passed directly to MQTT)""" 130 | if topic not in self.subscriptions: 131 | LOGGER.debug(f"New subscription for {topic}") 132 | self.subscriptions[topic] = [] 133 | # We need to mqtt-subscribe now: 134 | 135 | # This actually just sends a subscribe packet. We should 136 | # store this and the details and handle the setup in 137 | # _on_subscribe callback when the _mid (message id) is 138 | # confirmed. 139 | _mid = self.mqtt.subscribe(topic) 140 | else: 141 | if group in self.subscriptions[topic]: 142 | LOGGER.debug(f"{group} already subscibed to {topic}") 143 | return 144 | 145 | LOGGER.debug(f"{group} subscribed to {topic}") 146 | self.subscriptions[topic].append(group) 147 | 148 | def _on_subscribe(self, _client, _mid, _qos, _properties): 149 | LOGGER.debug('Subscribe callback {_mid}') 150 | 151 | async def unsubscribe(self, topic, group): 152 | """Un subscribes a group to an MQTT topic""" 153 | LOGGER.debug(f"unsubscribe {group} from {topic}") 154 | if topic in self.subscriptions: 155 | groups = self.subscriptions[topic] 156 | if group in groups: 157 | LOGGER.debug(f"{group} being unsubscribed from {topic}") 158 | groups.delete(topic) 159 | else: 160 | LOGGER.debug(f"{group} not subscribed to {topic}") 161 | if not len(groups): 162 | LOGGER.debug(f"No more {group}s, unsubscribing to {topic}") 163 | self.mqtt.unsubscribe(topic) 164 | LOGGER.debug(f"{topic} not subscribed") 165 | 166 | def publish(self, topic=None, payload=None, qos=2, retain=True): 167 | """Publish :param payload: to :param topic:""" 168 | LOGGER.debug(f"Publishing {topic} = {payload}") 169 | self.mqtt.publish(topic, payload, qos=qos, retain=retain) 170 | 171 | def ask_exit(self): 172 | """Handle outstanding messages and cleanly disconnect""" 173 | LOGGER.warning(f"{self} received signal asking to exit") 174 | self.stop_event.set() 175 | 176 | def groups_matching_topic(self, topic): 177 | groups = set() 178 | for sub, gs in self.subscriptions.items(): 179 | if sub == topic: # simple match 180 | groups.update(gs) 181 | elif self.topic_matches_sub(sub, topic): 182 | LOGGER.debug(f"Found matching groups {gs}") 183 | groups.update(gs) 184 | return groups 185 | 186 | # Taken from paho-mqtt - thanks :) 187 | @staticmethod 188 | def topic_matches_sub(sub, topic): 189 | """Check whether a topic matches a subscription. 190 | For example: 191 | foo/bar would match the subscription foo/# or +/bar 192 | non/matching would not match the subscription non/+/+ 193 | """ 194 | result = True 195 | multilevel_wildcard = False 196 | 197 | slen = len(sub) 198 | tlen = len(topic) 199 | 200 | if slen > 0 and tlen > 0: 201 | if (sub[0] == '$' and topic[0] != '$') or (topic[0] == '$' and sub[0] != '$'): 202 | return False 203 | 204 | spos = 0 205 | tpos = 0 206 | 207 | while spos < slen and tpos < tlen: 208 | if sub[spos] == topic[tpos]: 209 | if tpos == tlen-1: 210 | # Check for e.g. foo matching foo/# 211 | if spos == slen-3 and sub[spos+1] == '/' and sub[spos+2] == '#': 212 | result = True 213 | multilevel_wildcard = True 214 | break 215 | 216 | spos += 1 217 | tpos += 1 218 | 219 | if tpos == tlen and spos == slen-1 and sub[spos] == '+': 220 | spos += 1 221 | result = True 222 | break 223 | else: 224 | if sub[spos] == '+': 225 | spos += 1 226 | while tpos < tlen and topic[tpos] != '/': 227 | tpos += 1 228 | if tpos == tlen and spos == slen: 229 | result = True 230 | break 231 | 232 | elif sub[spos] == '#': 233 | multilevel_wildcard = True 234 | if spos+1 != slen: 235 | result = False 236 | break 237 | else: 238 | result = True 239 | break 240 | 241 | else: 242 | result = False 243 | break 244 | 245 | if not multilevel_wildcard and (tpos < tlen or spos < slen): 246 | result = False 247 | 248 | return result 249 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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Patents. 472 | 473 | A "contributor" is a copyright holder who authorizes use under this 474 | License of the Program or a work on which the Program is based. The 475 | work thus licensed is called the contributor's "contributor version". 476 | 477 | A contributor's "essential patent claims" are all patent claims 478 | owned or controlled by the contributor, whether already acquired or 479 | hereafter acquired, that would be infringed by some manner, permitted 480 | by this License, of making, using, or selling its contributor version, 481 | but do not include claims that would be infringed only as a 482 | consequence of further modification of the contributor version. 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You may not convey a covered 525 | work if you are a party to an arrangement with a third party that is 526 | in the business of distributing software, under which you make payment 527 | to the third party based on the extent of your activity of conveying 528 | the work, and under which the third party grants, to any of the 529 | parties who would receive the covered work from you, a discriminatory 530 | patent license (a) in connection with copies of the covered work 531 | conveyed by you (or copies made from those copies), or (b) primarily 532 | for and in connection with specific products or compilations that 533 | contain the covered work, unless you entered into that arrangement, 534 | or that patent license was granted, prior to 28 March 2007. 535 | 536 | Nothing in this License shall be construed as excluding or limiting 537 | any implied license or other defenses to infringement that may 538 | otherwise be available to you under applicable patent law. 539 | 540 | 12. No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | --------------------------------------------------------------------------------