django - 在 systemd 上使用 daphne 运行 django channel

Question

首先，很抱歉这个问题太长了，我希望你们中的一些人对此有耐心。

TL; DR:如何在 systemd 中正确加载 django 设置？

我正在关注本指南，Deploying Django Channels Using Daphne ，所以我可以运行一些实时应用程序(使用 WebSockets)。在没有 nginx 的情况下，从命令行运行 worker (python manage.py runworker) 和 interface (daphne)，我可以访问正确的 channel 消费者类，如下面的日志所示(这些是从 javascript 客户端触发的) :

2017-10-09 21:10:35,210 - DEBUG - worker - Got message on websocket.connect (reply daphne.response.CYeWgnNQoY!mwuQrazQtv)
2017-10-09 21:10:35,211 - DEBUG - runworker - websocket.connect
2017-10-09 21:10:35,211 - DEBUG - worker - Dispatching message on websocket.connect to api.consumers.OrderConsumer
2017-10-09 21:10:48,132 - DEBUG - worker - Got message on websocket.receive (reply daphne.response.CYeWgnNQoY!mwuQrazQtv)
2017-10-09 21:10:48,132 - DEBUG - runworker - websocket.receive
2017-10-09 21:10:48,132 - DEBUG - worker - Dispatching message on websocket.receive to api.consumers.OrderConsumer

这些事件由以下 javascript 调用触发:

ws = new WebSocket("ws://localhost:8000/order/1/")
ws.send("test")

使用 nginx，并在 systemd 上同时运行接口(interface)和工作程序，尽管使用了完全相同的触发器输入，但我得到了以下日志。

2017-10-09 20:38:35,503 - DEBUG - worker - Got message on websocket.connect (reply daphne.response.PPGuXtBmQD!EgUfaNZjUj)
2017-10-09 20:38:35,503 - DEBUG - runworker - websocket.connect
2017-10-09 20:38:35,503 - DEBUG - worker - Dispatching message on websocket.connect to channels.routing.connect_consumer
2017-10-09 20:38:42,993 - DEBUG - worker - Got message on websocket.receive (reply daphne.response.PPGuXtBmQD!EgUfaNZjUj)
2017-10-09 20:38:42,993 - DEBUG - runworker - websocket.receive
2017-10-09 20:38:42,993 - DEBUG - worker - Dispatching message on websocket.receive to channels.routing.null_consumer

请注意接收 channel 被路由到 null_consumer .我相信这里的问题很简单，channels.routing设置不好。由于我在两个版本中使用相同的设置(Django 设置文件)，这可能意味着设置本身没有被正确加载。请考虑以下文件。

## rest-api/farmaApp/settings.py

...
CHANNEL_LAYERS = {
    'default': {
        'BACKEND': 'asgi_redis.RedisChannelLayer',
        'CONFIG': {
            'hosts': [('localhost', 6379)],
        },
        'ROUTING': 'farmaApp.routing.channel_routing',
    }
}
...

应该设置channels.routing到:

## rest-api/farmaApp/routing.py

from channels.routing import route
from api.consumers import ws_connect, ws_disconnect, OrderConsumer

channel_routing = [
    route('websocket.connect', ws_connect, path=r'^/users/'),
    route('websocket.disconnect', ws_disconnect, path=r'^/users/'),
    OrderConsumer.as_route(path=r'^/order/(?P<order_id>[\d+])/'),
]

同样，我不认为配置本身是错误的，因为它可以在没有 systemd 的情况下工作。最后，这是我的 systemd 配置:

## /etc/systemd/system/daphne.service

[Unit]
Description=daphne daemon
After=network.target

[Service]
User=ubuntu
Group=www-data
WorkingDirectory=/home/ubuntu/rest-api
Environment=DJANGO_SETTINGS_MODULE=farmaApp.settings
ExecStart=/home/ubuntu/rest-api/env/bin/daphne --access-log /home/ubuntu/rest-api/access.log -b 0.0.0.0 -p 8001 farmaApp.asgi:channel_layer

[Install]
WantedBy=multi-user.target


## /etc/systemd/system/django_worker.service
[Unit]
Description=django_worker daemon
After=network.target

[Service]
User=ubuntu
Group=www-data
WorkingDirectory=/home/ubuntu/rest-api
Environment=DJANGO_SETTINGS_MODULE=farmaApp.settings
ExecStart=/home/ubuntu/rest-api/env/bin/python manage.py runworker -v 2

[Install]
WantedBy=multi-user.target

请注意我根据链接指南导出到环境的 DJANGO_SETTINGS_MODULE 变量的两个配置文件。我相信这没有按预期工作。

Answer 1

我刚刚部署了我的 Django Channels 应用程序，并且以下 systemd 服务文件在不使用主管的情况下为我工作:
/etc/systemd/system/django-channels-daphne.service

[Unit]
Description=daphne server script for my project
After=network.target

[Service]
User=webuser
Group=webuser
WorkingDirectory=/path/to/myproject
Environment=DJANGO_SECRET_KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Environment=DJANGO_ALLOWED_HOSTS=myapp.chatbot.ai
ExecStart=/path/to/python/virtualenv/bin/daphne -b 0.0.0.0 -p 8000 myproject.asgi:channel_layer
Restart=always

[Install]
WantedBy=multi-user.target

/etc/systemd/system/django-channels-runworker.service

[Unit]
Description=python runworker server for myproject
After=network.target

[Service]
User=webuser
Group=webuser
WorkingDirectory=/path/to/myproject
Environment=DJANGO_SECRET_KEY=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Environment=DJANGO_ALLOWED_HOSTS=myapp.chatbot.ai
ExecStart=/path/to/python/virtualenv/bin/python /path/to/myproject/manage.py runworker --threads 4 
Restart=always

[Install]
WantedBy=multi-user.target

/path/to/myproject/myproject/asgi.py

import os
import channels

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "myproject.settings")
channel_layer = channels.asgi.get_channel_layer()

/path/to/myproject/myproject/settings.py 中的一些行:

ALLOWED_HOSTS = [os.environ['DJANGO_ALLOWED_HOSTS']]
SECRET_KEY = os.environ['DJANGO_SECRET_KEY']