Adapt _process_response for runtime database selection (#827)

* use with context at runtime

* add comment explaining why context manager is better in this case

---------

Co-authored-by: Iker Zabala <iker.zabala@immersia.eu>

Author: izabala033

silk/middleware.py

@@ -143,29 +143,31 @@ def process_request(self, request):
         request_model = RequestModelFactory(request).construct_request_model()
         DataCollector().configure(request_model, should_profile=should_profile)
 
-    @transaction.atomic(using=router.db_for_write(models.SQLQuery))
     def _process_response(self, request, response):
-        Logger.debug('Process response')
-        with silk_meta_profiler():
-            collector = DataCollector()
-            collector.stop_python_profiler()
-            silk_request = collector.request
+        # Use a context manager instead of a decorator so db_for_write is evaluated at runtime,
+        # which is important for dynamic database configurations (e.g., multitenancy).
+        with transaction.atomic(using=router.db_for_write(models.SQLQuery)):
+            Logger.debug('Process response')
+            with silk_meta_profiler():
+                collector = DataCollector()
+                collector.stop_python_profiler()
+                silk_request = collector.request
+                if silk_request:
+                    ResponseModelFactory(response).construct_response_model()
+                    silk_request.end_time = timezone.now()
+                    collector.finalise()
+                else:
+                    Logger.error(
+                        'No request model was available when processing response. '
+                        'Did something go wrong in process_request/process_view?'
+                        '\n' + str(request) + '\n\n' + str(response)
+                    )
+            # Need to save the data outside the silk_meta_profiler
+            # Otherwise the  meta time collected in the context manager
+            # is not taken in account
             if silk_request:
-                ResponseModelFactory(response).construct_response_model()
-                silk_request.end_time = timezone.now()
-                collector.finalise()
-            else:
-                Logger.error(
-                    'No request model was available when processing response. '
-                    'Did something go wrong in process_request/process_view?'
-                    '\n' + str(request) + '\n\n' + str(response)
-                )
-        # Need to save the data outside the silk_meta_profiler
-        # Otherwise the  meta time collected in the context manager
-        # is not taken in account
-        if silk_request:
-            silk_request.save()
-        Logger.debug('Process response done.')
+                silk_request.save()
+            Logger.debug('Process response done.')
 
     def process_response(self, request, response):
         max_attempts = 2