Fix worker, scheduler docker command (#830)

Author: nkiryanov

{{ cookiecutter.name }}/Dockerfile

@@ -59,25 +59,30 @@ USER web
 RUN python manage.py compilemessages \
   && python manage.py collectstatic --noinput
 
-# Also to mark that when CMD is used in shell form, it is a conscious decision
-SHELL ["/bin/bash", "-c"]
-
 
+#
+# web image
+#
 FROM base AS web
 HEALTHCHECK --interval=15s --timeout=15s --start-period=15s --retries=3 \
   CMD wget --quiet --tries=1 --spider http://localhost:8000/api/v1/healthchecks/
 
 CMD ["sh", "-c", "python manage.py migrate && uwsgi --master --http=:8000 --venv=/code/.venv/ --wsgi=app.wsgi --workers=2 --threads=2 --harakiri=25 --max-requests=1000 --log-x-forwarded-for"]
 
+#
+# worker image
+#
 FROM base AS worker
 
 ENV _CELERY_APP=app.celery
 HEALTHCHECK --interval=15s --timeout=15s --start-period=5s --retries=3 \
   CMD celery --app=${_CELERY_APP} inspect ping --destination=celery@$HOSTNAME
 
-CMD ["celery", "--app=${_CELERY_APP}", "worker", "--concurrency=${CONCURENCY:-2}", "--hostname=celery@%h", "--max-tasks-per-child=${MAX_REQUESTS_PER_CHILD:-50}", "--time-limit=${TIME_LIMIT:-900}", "--soft-time-limit=${SOFT_TIME_LIMIT:-45}"]
-
+CMD ["sh", "-c", "celery --app=${_CELERY_APP} worker --concurrency=${CONCURENCY:-2} --hostname=celery@%h --max-tasks-per-child=${MAX_REQUESTS_PER_CHILD:-50} --time-limit=${TIME_LIMIT:-900} --soft-time-limit=${SOFT_TIME_LIMIT:-45}"]
 
+#
+# scheduler image
+#
 FROM base AS scheduler
 
 ENV _SCHEDULER_DB_PATH=/var/db/scheduler
@@ -88,4 +93,4 @@ VOLUME ${_SCHEDULER_DB_PATH}
 
 ENV _CELERY_APP=app.celery
 HEALTHCHECK NONE
-CMD ["celery", "--app=${_CELERY_APP}", "beat", "--pidfile=/tmp/celerybeat.pid", "--schedule=${_SCHEDULER_DB_PATH}/celerybeat-schedule.db"]
+CMD ["sh", "-c", "celery --app=${_CELERY_APP} beat --pidfile=/tmp/celerybeat.pid --schedule=${_SCHEDULER_DB_PATH}/celerybeat-schedule.db"]