Add config options for max file upload sizes (#2199)

* feat(config): Add config options for max file upload sizes

Closes #2198

* Apply suggestions from code review

Fix docs and comment in settings.py

Co-authored-by: Richard Schreiber <wiffbi@gmail.com>

* Fix import order using isort

Co-authored-by: Richard Schreiber <wiffbi@gmail.com>

src/pretix/api/serializers/item.py

@@ -34,6 +34,7 @@
 import os.path
 from decimal import Decimal
 
+from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db import transaction
 from django.db.models import QuerySet
@@ -161,7 +162,7 @@ class ItemSerializer(I18nAwareModelSerializer):
     meta_data = MetaDataField(required=False, source='*')
     picture = UploadedFileField(required=False, allow_null=True, allowed_types=(
         'image/png', 'image/jpeg', 'image/gif'
-    ), max_size=10 * 1024 * 1024)
+    ), max_size=settings.FILE_UPLOAD_MAX_SIZE_IMAGE)
 
     class Meta:
         model = Item

src/pretix/api/serializers/order.py

@@ -26,6 +26,7 @@ from collections import Counter, defaultdict
 from decimal import Decimal
 
 import pycountry
+from django.conf import settings
 from django.core.files import File
 from django.db.models import F, Q
 from django.utils.timezone import now
@@ -191,7 +192,7 @@ class AnswerSerializer(I18nAwareModelSerializer):
         )
         if cf.type not in allowed_types:
             raise ValidationError('The submitted file "{fid}" has a file type that is not allowed in this field.'.format(fid=data))
-        if cf.file.size > 10 * 1024 * 1024:
+        if cf.file.size > settings.FILE_UPLOAD_MAX_SIZE_OTHER:
             raise ValidationError('The submitted file "{fid}" is too large to be used in this field.'.format(fid=data))
 
         data['options'] = []

src/pretix/api/views/checkin.py

@@ -20,6 +20,7 @@
 # <https://www.gnu.org/licenses/>.
 #
 import django_filters
+from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db import transaction
 from django.db.models import (
@@ -603,7 +604,7 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
         )
         if cf.type not in allowed_types:
             raise ValidationError('The submitted file "{fid}" has a file type that is not allowed in this field.'.format(fid=data))
-        if cf.file.size > 10 * 1024 * 1024:
+        if cf.file.size > settings.FILE_UPLOAD_MAX_SIZE_OTHER:
             raise ValidationError('The submitted file "{fid}" is too large to be used in this field.'.format(fid=data))
 
         return cf.file