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As practice, I'm trying to deploy Andrew Godwin's multichat example with Django Channels 2.1.1 on DigitalOcean Ubuntu 16.04.4. However, I don't know how to exit the Ubuntu server without Channels' Daphne server stopping.

Right now, almost my entire familiarity with deployment comes from this tutorial, and that's how I've deployed the site. But according to Channels' documentation, I have to run one of these three in production to start Daphne:

  • daphne myproject.asgi:application
  • daphne -p 8001 myproject.asgi:application
  • daphne -b 0.0.0.0 -p 8001 myproject.asgi:application

So, in addition to following the DigitalOcean tutorial, I ran these also. The third one worked for me and the site ran well. However, if I exit shell on Ubuntu, Daphne stops too.

The tutorial has gunicorn access a sock file (--bind unix:/home/sammy/myproject/myproject.sock), and in my research so far I've seen on a few sites published before 2018 that somehow somewhere a daphne.sock file is generated. So, I guess Channels deploys similarly? But I haven't seen any details about how this is done.

How do I deploy the multichat example so I can exit the Ubuntu web server without Daphne stopping?

Update 6 May 2018, 8pm CET:

I tried kagronick's solution below and created a systemd file at /etc/systemd/system/daphne_seb.service:

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

[Service]
User=root
Group=www-data
WorkingDirectory=/home/seb/seb
ExecStart=/home/seb/env_seb/bin/python /home/seb/seb/manage.py daphne -b 0.0.0.0 -p 8001 multichat.asgi:application
Restart=on-failure

[Install]
WantedBy=multi-user.target

I did systemctl daemon-reload and systemctl start daphne_seb.service and it ran for a couple of seconds. Then, systemctl status daphne_seb.service said Unknown command: 'daphne'.

I tried restarting it. Then I rebooted the OS. Now status says:

daphne_seb.service - daphne daemon for seb
   Loaded: loaded (/etc/systemd/system/daphne_seb.service; enabled; vendor preset: enabled)
   Active: inactive (dead) (Result: exit-code) since Sun 2018-05-06 19:33:31 UTC; 1s ago
  Process: 2459 ExecStart=/home/seb/env_seb/bin/python /home/seb/seb/manage.py daphne -b 0.0.0.0 -p 8001 multichat.asgi:application (code=exited, status=1
 Main PID: 2459 (code=exited, status=1/FAILURE)

May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Main process exited, code=exited, status=1/FAILURE
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Unit entered failed state.
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Failed with result 'exit-code'.
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Service hold-off time over, scheduling restart.
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: Stopped daphne daemon for seb.
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Start request repeated too quickly.
May 06 19:33:31 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: Failed to start daphne daemon for seb.

I checked the filepaths. They're correct. I also tried adding Environment=DJANGO_SETTINGS_MODULE=multichat.settings, which I saw here. But that didn't help either.

Update 6 May 2018, 10pm CET:

Then, I read here that only 5 restarts are allowed within a 10-second period. So I removed Restart=on-failure to start the service myself.

This brought me back to Unknown command: 'daphne'. This solution suggested to me that I shouldn't be pointing to Python but to Daphne in my virtualenv, so I changed it: ExecStart=/home/seb/env_seb/bin/daphne. I also removed /home/seb/seb/manage.py based on the same solution. This gave me a new problem:

daphne_seb.service - daphne daemon for seb
   Loaded: loaded (/etc/systemd/system/daphne_seb.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Sun 2018-05-06 19:55:24 UTC; 5s ago
  Process: 2903 ExecStart=/home/seb/env_seb/bin/daphne daphne -b 0.0.0.0 -p 8001 multichat.asgi:application (code=exited, status=2)
 Main PID: 2903 (code=exited, status=2)

May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               [-v VERBOSITY] [-t HTTP_TIMEOUT] [--access-log ACCESS_LOG]
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               [--ping-interval PING_INTERVAL] [--ping-timeout PING_TIMEOUT]
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               [--application-close-timeout APPLICATION_CLOSE_TIMEOUT]
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               [--ws-protocol [WS_PROTOCOLS [WS_PROTOCOLS ...]]]
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               [--root-path ROOT_PATH] [--proxy-headers]
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]:               application
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 daphne[2903]: daphne: error: unrecognized arguments: multichat.asgi:application
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Unit entered failed state.
May 06 19:55:24 ubuntu-s-1vcpu-1gb-ams3-01 systemd[1]: daphne_seb.service: Failed with result 'exit-code'.

I check my multichat.asgi:application and it's in the right place. So I can't figure out why it says error: unrecognized arguments: multichat.asgi:application.

4

2 回答 2

8

我使用systemd。您将在 /etc/systemd/system/daphne.service 中设置一个单元文件

内容如下：

[Unit]
Description=My Daphne Service
After=network.target

[Service]
Type=simple
User=wwwrunn
WorkingDirectory=/srv/myapp
ExecStart=/path/to/my/virtualenv/bin/python /path/to/daphne -b 0.0.0.0 -p 8001 myproject.asgi:application
Restart=on-failure

[Install]
WantedBy=multi-user.target

我以这种方式配置了我的应用程序的所有部分。它允许他们在崩溃时恢复。Systemd 可以处理所有日志记录。它们都以正确的顺序开始。使用 Type=simple 这样您就不需要对 PID 文件进行任何分叉或写入。它只会管理一个进程。我运行其中的一些来分散负载。

放置此文件后，您将运行

systemctl daemon-reload
systemctl start daphne.service
于 2018-05-06T17:44:51.020 回答
2

我的问题其实和这个一样。此类问题通常会发送到此解决方案。一开始我并没有意识到这个问题与我的问题相同，因为（i.）我还不熟悉使用 Channels 部署的词汇，并且（ii.）很多这些问题及其解决方案都提到了已经存在的问题Channels 2 已弃用。我丢失了页面，但例如 Channels 2 不需要我们这样做python manage.py runworker。

还有暴发户和systemd的问题。几种解决方案使用 upstart 脚本。但是，我有一种模糊的感觉，如果我在 Ubuntu 16.04.4 上，我应该使用 systemd。我做了一个谷歌，发现 systemd 确实取代了暴发户，根据这样的文章。

@kagronick 提供了正确的 systemd 解决方案，但我必须对其进行编辑以使其适合我：

# /etc/systemd/system/daphne_seb.service

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

[Service]
User=root
Group=www-data
WorkingDirectory=/home/seb/seb
ExecStart=/home/seb/env_seb/bin/daphne -b 0.0.0.0 -p 8001 multichat.asgi:application

# I turned this off for testing purposes.
# Still not sure if should use 'on-failure' or 'always'. 
# Restart=on-failure

[Install]
WantedBy=multi-user.target

然后在外壳中：

systemctl daemon-reload
systemctl start daphne_seb.service
于 2018-05-07T00:01:25.887 回答