MT#56231 enable django-celery-beat via database

* migrate periodic task definition to database
  via configuration

Be aware that we are getting hit by this issue:
https://github.com/celery/django-celery-beat/issues/647
Solution is not yet released:
2798e36fd8

Change-Id: Id72130bdd5fe97be3824f5d9d7a3905af44d3597

repoapi/celery.py

@@ -15,7 +15,6 @@
 import os
 
 from celery import Celery
-from celery.schedules import crontab
 from django_structlog.celery.steps import DjangoStructLogInitStep
 
 # set the default Django settings module for the 'celery' program.
@@ -49,12 +48,3 @@ def process_result(jbi_id: str, path_envVars: str):
         "release_changed.tasks.process_result",
         args=[jbi_id, path_envVars],
     )
-
-
-@app.on_after_configure.connect
-def setup_periodic_tasks(sender, **kwargs):
-    sender.add_periodic_task(
-        crontab(hour=7, minute=30, day_of_month=15),
-        "gerrit.tasks.cleanup",
-        args=[4],
-    )

repoapi/settings/common.py

@@ -32,6 +32,7 @@ INSTALLED_APPS = [
     "rest_framework_api_key",
     "drf_spectacular",
     "django_assets",
+    "django_celery_beat",
     "django_celery_results",
     "django_extensions",
     "django_filters",
@@ -169,5 +170,6 @@ CELERY_TASK_SERIALIZER = "json"
 CELERY_RESULT_SERIALIZER = "json"
 CELERY_ACCEPT_CONTENT = ["application/json"]
 CELERY_RESULT_BACKEND = "django-db"
+CELERY_BEAT_SCHEDULER = "django_celery_beat.schedulers:DatabaseScheduler"
 
 API_KEY_CUSTOM_HEADER = "HTTP_API_KEY"

repoapi/settings/prod.py

@@ -161,6 +161,11 @@ CELERY_BEAT_SCHEDULE = {
         "schedule": crontab(hour=7, minute=30, day_of_week="sunday"),
         "args": (None, 1),
     },
+    "gerrit-cleanup": {
+        "schedule": crontab(hour=7, minute=30, day_of_month=15),
+        "tasks": "gerrit.tasks.cleanup",
+        "args": (4),
+    },
 }
 CELERY_TIMEZONE = "UTC"