Configuring Supervisor for Daphne (Django Channels)

In the supervisor ASGI config file, in the following line

command=/home/ubuntu/django_app/venv/bin/daphne -u /run/daphne/daphne%(process_num)d.sock --fd 0 --access-log - --proxy-headers mysite.asgi:application

replace --fd 0 with --endpoint fd:fileno=0.

Issue: https://github.com/django/daphne/issues/234

Fabio's answer, with replacing the file descriptor parameter for the endpoint parameter, presents a quick workaround for this problem (which appeared to be a bug in the Daphne code).

However, the fix in Daphne repository was quickly committed so that the original instructions work well.

As a side note (for people still getting critical listen failures which I wrote about in the original question), please be sure that the physical location for socket files (/run/daphne/ in my case) is accessible - I spent too much time just to discover that simply creating the daphne folder in /run catalog does the job (even though I run everything with sudo)... For precautionary measures one may consider redirecting the socket files to another folder, e.g. /tmp which does let creating a directory without sudo permission.