update crontab automatically on changes to crontab.txt

cron/cron-entrypoint.sh

@@ -2,13 +2,26 @@
 
 set -e
 
-if [ "$SETUP_SERVICE" == "true" ]; then
-  echo "SETUP_SERVICE has value '$SETUP_SERVICE' - starting cron setup."
+# Function to update crontab from crontab.txt
+update_crontab() {
+  # prepend environment variables to /tmp/new_crontab.txt 
+  # to be able topass them to cron jobs
   (printenv; cat /tmp/crontab.txt) > /tmp/new_crontab.txt
+  # use /tmp/new_crontab.txt as crontab
   crontab /tmp/new_crontab.txt
+}
+
+if [ "$SETUP_SERVICE" == "true" ]; then
+  echo "SETUP_SERVICE has value '$SETUP_SERVICE' - starting cron setup."
+  # Monitor crontab.txt for changes and update crontab if they occurr 
+  # run loop in background to start cron service
+  while true; do
+    update_crontab
+    inotifywait -e modify /tmp/crontab.txt  
+  done &
+  sleep 1
   cron -f || exit 1
-  echo "cron setup complete."
 else
   echo "SETUP_SERVICE has value '$SETUP_SERVICE' - skipping cron setup."
   echo "To start cron setup, set SETUP_SERVICE to 'true' in .env file."
-fi
\ No newline at end of file
+fi

cron/requirements.txt

-psycopg2-binary~=2.9.2
\ No newline at end of file
+psycopg2-binary~=2.9.2
+python-crontab~=3.0.0
\ No newline at end of file