ajaidanial · May 8, 2021 20:51 · Sep 19, 2019
diff --git a/docker-start-celery-multi-worker-entrypoint b/docker-start-celery-multi-worker-entrypoint
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+# safety switch, exit script if there's error. Full command of shortcut `set -e`
+set -o errexit
+# safety switch, uninitialized variables will stop script. Full command of shortcut `set -u`
+set -o nounset
+
+# tear down function
+teardown()
+{
+    echo " Signal caught..."
+    echo "Stopping celery multi gracefully..."
+
+    # send shutdown signal to celery workser via `celery multi`
+    # command must mirror some of `celery multi start` arguments
+    celery -A config.celery_app multi stop 3 --pidfile=./celery-%n.pid --logfile=./celery-%n%I.log
+
+    echo "Stopped celery multi..."
+    echo "Stopping last waited process"
+    kill -s TERM "$child" 2> /dev/null
+    echo "Stopped last waited process. Exiting..."
+    exit 1
+}
+
+# start 3 celery worker via `celery multi` with declared logfile for `tail -f`
+celery -A config.celery_app multi start 3 -l INFO -Q:1 queue1 -Q:2 queue1 -Q:3 queue3,celery -c:1-2 1 \
+    --pidfile=./celery-%n.pid \
+    --logfile=./celery-%n%I.log
+
+# start trapping signals (docker sends `SIGTERM` for shudown)
+trap teardown SIGINT SIGTERM
+
+# tail all the logs continuously to console for `docker logs` to see
+tail -f ./celery*.log &
+
+# capture process id of `tail` for tear down
+child=$!
+
+# waits for `tail -f` indefinitely and allows external signals,
+# including docker stop signals, to be captured by `trap`
+wait "$child"