Merge "Fix zone migration instance not found issue" into stable/2025.2

releasenotes/notes/bug-2098984-zone-migration-instance-not-found-b9ce947dd3e7e020.yaml

@@ -0,0 +1,9 @@
+---
+fixes:
+  - |
+    Fixes a bug in the zone migration strategy where audits would fail due to
+    an unhandled exception when trying to plan instance migration that exist
+    in Nova but not in Watcher's compute model.
+    The strategy now filters out the elements that are not found in the model,
+    allowing the audit to complete successfully. For more details, please see
+    `Bug #2098984 <https://bugs.launchpad.net/watcher/+bug/2098984>`_.

watcher/decision_engine/strategy/strategies/zone_migration.py

@@ -540,7 +540,7 @@ class ZoneMigration(base.ZoneMigrationBaseStrategy):
 
         return [i for i in self.nova.get_instance_list()
                 if getattr(i, 'OS-EXT-SRV-ATTR:host') in src_node_list and
-                self.compute_model.get_instance_by_uuid(i.id)]
+                self.compute_model.has_node(i.id)]
 
     def get_volumes(self):
         """Get migrate target volumes

watcher/tests/decision_engine/strategy/strategies/test_zone_migration.py

@@ -17,7 +17,6 @@ from unittest import mock
 
 import cinderclient
 import novaclient
-from watcher.common import exception as watcher_exception
 from watcher.common import utils
 from watcher.decision_engine.strategy import strategies
 from watcher.tests.decision_engine.model import faker_cluster_state
@@ -168,15 +167,9 @@ class TestZoneMigration(TestBaseStrategy):
         # Mock nova helper to return our test instance
         self.m_n_helper.get_instance_list.return_value = [instance_on_src1]
 
-        # FIXME(dviroel): Fix this test together with bug #2098984
-        # It should return an empty list and not raise an exception
         # Verify that the instance does not exist in the model
-        # instances = self.strategy.get_instances()
-        # self.assertEqual([], instances)
-
-        self.assertRaises(
-            watcher_exception.InstanceNotFound,
-            self.strategy.get_instances)
+        instances = self.strategy.get_instances()
+        self.assertEqual([], instances)
 
     def test_get_volumes_with_volume_not_found(self):
         # Create a test volume without an known id