[OSDEV-1467] Block post api facilities endpoint active switch (#428)

[OSDEV-1467](https://opensupplyhub.atlassian.net/browse/OSDEV-1467)
Implemented disabling endpoint POST /api/facilities/ during the release
process. It is raising an error message with status code 503.


![image](https://github.com/user-attachments/assets/6c3e57ff-b1c4-4c72-ade0-b3dd51d78687)

![image](https://github.com/user-attachments/assets/244ea28a-7597-416c-ba0d-a0af796730a6)




[OSDEV-1467]:
https://opensupplyhub.atlassian.net/browse/OSDEV-1467?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

---------

Co-authored-by: Inessa Druzhkova <[email protected]>

doc/release/RELEASE-NOTES.md

@@ -55,6 +55,7 @@ to modify moderation event `status`.
 * [OSDEV-1347](https://opensupplyhub.atlassian.net/browse/OSDEV-1347) - Create GET request for `v1/moderation-events/{moderation_id}` endpoint.
 * Update `/v1/production-locations/{os_id}` endpoint to return a single object instead of multiple objects. Also, add unit tests for the `ProductionLocationsViewSet`.
 * The RDS instance has been upgraded as follows: for `production` and `preprod`, it is now `db.m6in.8xlarge`, and for `test`, it has been upgraded to `db.t3.xlarge`.
+* [OSDEV-1467](https://opensupplyhub.atlassian.net/browse/OSDEV-1467) - Implemented disabling endpoint `POST /api/facilities/` during the release process. It is raising an error message with status code 503.
 
 ### Architecture/Environment changes
 * Increased the memory for the Dedupe Hub instance from 8GB to 12GB in the `production` and `pre-prod` environments to reduce the risk of container overload and minimize the need for reindexing in the future.

src/django/api/constants.py

@@ -194,6 +194,9 @@ class NumberOfWorkersRanges:
 
 class ErrorMessages:
     GEOCODED_NO_RESULTS = "The address you submitted can not be geocoded."
+    MAINTENANCE_MODE = ('Open Supply Hub is undergoing maintenance and '
+                        'not accepting new data at the moment. Please '
+                        'try again in a few minutes.')
 
 
 class FacilitiesDownloadSettings:

src/django/api/exceptions.py

@@ -10,6 +10,6 @@ class BadRequestException(APIException):
 
 class ServiceUnavailableException(APIException):
     status_code = status.HTTP_503_SERVICE_UNAVAILABLE
-    default_detail = 'Service is temporarily unavailable due to maintenance \
-        work. Please try again later.'
+    default_detail = ('Service is temporarily unavailable due to maintenance'
+                      'work. Please try again later.')
     default_code = 'service_unavailable'

src/django/api/views/facility/facilities_view_set.py

@@ -11,6 +11,7 @@
 from contricleaner.lib.exceptions.handler_not_set_error \
     import HandlerNotSetError
 
+from api.exceptions import ServiceUnavailableException
 from api.helpers.helpers import validate_workers_count
 from oar.settings import (
     MAX_ATTACHMENT_SIZE_IN_BYTES,
@@ -67,7 +68,8 @@
     FacilityMergeQueryParams,
     ProcessingAction,
     UpdateLocationParams,
-    FacilityClaimStatuses
+    FacilityClaimStatuses,
+    ErrorMessages,
 )
 from ...exceptions import BadRequestException
 from ...facility_history import (
@@ -576,6 +578,8 @@ def create(self, request):
         """  # noqa
         # Adding the @permission_classes decorator was not working so we
         # explicitly invoke our custom permission class.
+        if switch_is_active('disable_list_uploading'):
+            raise ServiceUnavailableException(ErrorMessages.MAINTENANCE_MODE)
         if not IsRegisteredAndConfirmed().has_permission(request, self):
             return Response(status=status.HTTP_401_UNAUTHORIZED)
         if not flag_is_active(request._request,

src/django/api/views/facility/facility_list_view_set.py

@@ -27,6 +27,7 @@
 from api.constants import (
     FacilityListItemsQueryParams,
     ProcessingAction,
+    ErrorMessages,
 )
 from api.exceptions import ServiceUnavailableException
 from ...facility_history import create_dissociate_match_change_reason
@@ -92,10 +93,7 @@ def create(self, request):
             }
         """
         if switch_is_active('disable_list_uploading'):
-            raise ServiceUnavailableException('Open Supply Hub is undergoing \
-                                     maintenance and not accepting new \
-                                     data at the moment. Please try again \
-                                     in a few minutes.')
+            raise ServiceUnavailableException(ErrorMessages.MAINTENANCE_MODE)
         if 'file' not in request.data:
             raise ValidationError('No file specified.')
         uploaded_file = request.data['file']