celery config

/etc/tmpfiles.d/celery-challenge.conf

d /var/run/challenge 0755 www-data www-data -
d /var/log/challenge 0755 www-data www-data -

/etc/celery-challenge.conf

# Name of nodes to start
# here we have a single node
CELERYD_NODES="w1"
# or we could have three nodes:
#CELERYD_NODES="w1 w2 w3"

# Absolute or relative path to the 'celery' command:
CELERY_BIN="/var/www/challenge/env/bin/celery"

# App instance to use
CELERY_APP="challenge"

# How to call manage.py
CELERYD_MULTI="multi"

# Extra command-line arguments to the worker
CELERYD_OPTS="--time-limit=300 --concurrency=8"

# - %n will be replaced with the first part of the nodename.
# - %I will be replaced with the current child process index
#   and is important when using the prefork pool to avoid race conditions.
CELERYD_PID_FILE="/var/run/challenge/celery-%n.pid"
CELERYD_LOG_FILE="/var/log/challenge/celery-%n%I.log"
CELERYD_LOG_LEVEL="INFO"

/etc/systemd/system/celery-challenge.service

[Unit]
Description=Celery Service
After=network.target

[Service]
Type=forking
User=www-data
Group=www-data
EnvironmentFile=-/etc/celery-challenge.conf
WorkingDirectory=/var/www/challenge
ExecStart=/bin/sh -c '${CELERY_BIN} multi start ${CELERYD_NODES} \
 -A ${CELERY_APP} --pidfile=${CELERYD_PID_FILE} \
 --logfile=${CELERYD_LOG_FILE} --loglevel=${CELERYD_LOG_LEVEL} ${CELERYD_OPTS}'
ExecStop=/bin/sh -c '${CELERY_BIN} multi stopwait ${CELERYD_NODES} \
 --pidfile=${CELERYD_PID_FILE}'
ExecReload=/bin/sh -c '${CELERY_BIN} multi restart ${CELERYD_NODES} \
 -A ${CELERY_APP} --pidfile=${CELERYD_PID_FILE} \
 --logfile=${CELERYD_LOG_FILE} --loglevel=${CELERYD_LOG_LEVEL} ${CELERYD_OPTS}'

[Install]
WantedBy=multi-user.target