Use celery_once to prevent repeat task queueing.

Prevent group updates from being queued multiple times per user.

Default graceful to prevent raising exceptions.

allianceauth/project_template/project_name/celery.py

@@ -11,6 +11,13 @@ app = Celery('{{ project_name }}')
 # Using a string here means the worker don't have to serialize
 # the configuration object to child processes.
 app.config_from_object('django.conf:settings')
+app.conf.ONCE = {
+  'backend': 'celery_once.backends.Redis',
+  'settings': {
+    'url': 'redis://localhost:6379/0',
+    'default_timeout': 60 * 60
+  }
+}
 
 # Load task modules from all registered Django app configs.
 app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)