Allow to adjust ticket cache duration

doc/admin/config.rst

@@ -339,6 +339,15 @@ application. If you want to use sentry, you need to set a DSN in the configurati
     You will be given this value by your sentry installation.
 
 
+Caching
+-------
+
+You can adjust some caching settings to control how much storage pretix uses::
+
+    [cache]
+    tickets=48  ; Number of hours tickets (PDF, passbook, …) are cached
+
+
 Secret length
 -------------
 

src/pretix/base/services/cleanup.py

@@ -1,5 +1,6 @@
 from datetime import timedelta
 
+from django.conf import settings
 from django.dispatch import receiver
 from django.utils.timezone import now
 from django_scopes import scopes_disabled
@@ -31,9 +32,9 @@ def clean_cached_files(sender, **kwargs):
 @receiver(signal=periodic_task)
 @scopes_disabled()
 def clean_cached_tickets(sender, **kwargs):
-    for cf in CachedTicket.objects.filter(created__lte=now() - timedelta(days=3)):
+    for cf in CachedTicket.objects.filter(created__lte=now() - timedelta(hours=settings.CACHE_TICKETS_HOURS)):
         cf.delete()
-    for cf in CachedCombinedTicket.objects.filter(created__lte=now() - timedelta(days=3)):
+    for cf in CachedCombinedTicket.objects.filter(created__lte=now() - timedelta(hours=settings.CACHE_TICKETS_HOURS)):
         cf.delete()
     for cf in CachedTicket.objects.filter(created__lte=now() - timedelta(minutes=30), file__isnull=True):
         cf.delete()

src/pretix/settings.py

@@ -241,6 +241,8 @@ else:
 
 SESSION_COOKIE_DOMAIN = config.get('pretix', 'cookie_domain', fallback=None)
 
+CACHE_TICKETS_HOURS = config.getint('cache', 'tickets', fallback=24 * 3)
+
 ENTROPY = {
     'order_code': config.getint('entropy', 'order_code', fallback=5),
     'ticket_secret': config.getint('entropy', 'ticket_secret', fallback=32),