Decouple /livez endpoint from the database

DomainMiddleware.process_view() runs Domain.objects.get() on every
request, including /livez/. This causes the liveness probe to fail
when the database is unavailable, triggering cascading pod restarts.

Add a skip_domain_middleware flag to LivezView and honour it in
DomainMiddleware so the probe depends only on the gunicorn worker
being alive.

Fixes #7721

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dkliban

CHANGES/7721.bugfix

@@ -0,0 +1 @@
+Decoupled the `/livez` liveness probe from the database so it returns 200 even when the database is unavailable.

pulpcore/app/views/status.py

@@ -145,6 +145,8 @@ class LivezView(APIView):
     # allow anyone to access the liveness api
     authentication_classes = []
     permission_classes = []
+    # Skip domain DB lookup so this probe stays independent of the database
+    skip_domain_middleware = True
 
     @extend_schema(
         summary="Inspect liveness of Pulp's REST API.",

pulpcore/middleware.py

@@ -38,6 +38,10 @@ def __call__(self, request):
 
     def process_view(self, request, view_func, view_args, view_kwargs):
         """Remove the domain name if present, called right before view_func is called."""
+        view_class = getattr(view_func, "view_class", None) or getattr(view_func, "cls", None)
+        if view_class and getattr(view_class, "skip_domain_middleware", False):
+            view_kwargs.pop("pulp_domain", None)
+            return None
         domain_name = view_kwargs.pop("pulp_domain", "default")
         try:
             domain = Domain.objects.get(name=domain_name)

pulpcore/tests/unit/test_middleware.py

@@ -0,0 +1,35 @@
+from unittest.mock import MagicMock, patch
+
+from django.test import TestCase
+
+from pulpcore.middleware import DomainMiddleware
+from pulpcore.plugin.find_url import find_api_root
+
+
+class TestLivezNoDatabaseAccess(TestCase):
+    """Test that GET /livez/ makes zero database queries."""
+
+    def test_livez_makes_no_database_queries(self):
+        _, api_v3_path = find_api_root(set_domain=False, rewrite_header=False)
+        with self.assertNumQueries(0):
+            response = self.client.get(f"{api_v3_path}livez/")
+        self.assertEqual(response.status_code, 200)
+
+
+class TestDomainMiddlewareSkip(TestCase):
+    """Test that DomainMiddleware skips DB lookup for views with skip_domain_middleware=True."""
+
+    def setUp(self):
+        self.middleware = DomainMiddleware(get_response=MagicMock())
+        self.request = MagicMock()
+
+    @patch("pulpcore.middleware.Domain.objects")
+    @patch("pulpcore.middleware.set_domain")
+    def test_does_db_lookup_when_flag_not_set(self, mock_set_domain, mock_domain_objects):
+        view_class = type("NormalView", (), {})
+        view_func = MagicMock(view_class=view_class)
+        view_kwargs = {"pulp_domain": "default"}
+
+        self.middleware.process_view(self.request, view_func, [], view_kwargs)
+
+        mock_domain_objects.get.assert_called_once_with(name="default")