starting celery workers as daemons - django

Question

I am trying to set up celery to run in production. I have been following the instructions here:
https://www.linode.com/docs/development/python/task-queue-celery-rabbitmq/#start-the-workers-as-daemons
I am currently up to step #7, i.e. 'sudo systemctl start celeryd'. When I am running this I am being told celeryd.service has failed. I have run 'journalctl -xe' to find the log details, which I have copied in below.
I'm very new to celery so I'm finding difficulty in interpreting the log file to figure out what's going wrong, so any help would be much appreciated. If more information is needed then please ask and i'll do my best to provide it.
Apr 05 10:44:47 user-admin systemd[6477]: celeryd.service: Failed to determine user credentials: No such process
Apr 05 10:44:47 user-admin systemd[6477]: celeryd.service: Failed at step USER spawning /bin/sh: No such process
-- Subject: Process /bin/sh could not be executed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The process /bin/sh could not be executed and failed.
--
-- The error number returned by this process is 3.
Apr 05 10:44:47 user-admin systemd[1]: celeryd.service: Control process exited, code=exited status=217
Apr 05 10:44:47 user-admin systemd[1]: celeryd.service: Failed with result 'exit-code'.
Apr 05 10:44:47 user-admin systemd[1]: Failed to start Celery Service.
-- Subject: Unit celeryd.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Unit celeryd.service has failed.
--
-- The result is RESULT.
Apr 05 10:44:47 user-admin sudo[6472]: pam_unix(sudo:session): session closed for user root
Apr 05 10:45:01 user-admin CRON[6481]: pam_unix(cron:session): session opened for user root by (uid=0)
Apr 05 10:45:01 user-admin CRON[6482]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Apr 05 10:45:01 user-admin CRON[6481]: pam_unix(cron:session): session closed for user root
Apr 05 10:45:05 user-admin sudo[6485]: djangoadmin : TTY=pts/1 ; PWD=/var/log/celery ; USER=root ; COMMAND=/bin/journalctl -xe

Answer 1

Remove the /bin/sh -c from ExecStart, ExecStop and ExecRestart (in your celeryd.service).
Assuming you have a virtual environment in /home/celery/venv, and Celery installed in this environment, then your ExecStart (and other Exec* lines) should look like:
ExecStart=/home/celery/venv/bin/celery multi start ${CELERYD_NODES} \
-A ${CELERY_APP} --pidfile=${CELERYD_PID_FILE} \
--logfile=${CELERYD_LOG_FILE} --loglevel=${CELERYD_LOG_LEVEL}
${CELERYD_OPTS}'
To create virtual environment do something like: python3 -m venv /home/celery/venv
If the celery user is created in a different path, then change the /home/celery in the code above to the appropriate "home" of the celery user...
UPDATE: If you used the same config file as on the Linode page, then you may use ExecStart=${CELERY_BIN} multi start...