Merge "Avoid unbound instance_uuid var during delete" into stable/wallaby

2 files changed, 34 insertions, 4 deletions

diff --git a/nova/compute/api.py b/nova/compute/api.py
index d938a910e5..774eb538c0 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -2231,6 +2231,12 @@ class API(base.Base):
         # Normal delete should be attempted.
         may_have_ports_or_volumes = compute_utils.may_have_ports_or_volumes(
             instance)
+
+        # Save a copy of the instance UUID early, in case
+        # _lookup_instance returns instance = None, to pass to
+        # _local_delete_cleanup if needed.
+        instance_uuid = instance.uuid
+
         if not instance.host and not may_have_ports_or_volumes:
             try:
                 if self._delete_while_booting(context, instance):
@@ -2244,10 +2250,6 @@ class API(base.Base):
                 # full Instance or None if not found. If not found then it's
                 # acceptable to skip the rest of the delete processing.
 
-                # Save a copy of the instance UUID early, in case
-                # _lookup_instance returns instance = None, to pass to
-                # _local_delete_cleanup if needed.
-                instance_uuid = instance.uuid
                 cell, instance = self._lookup_instance(context, instance.uuid)
                 if cell and instance:
                     try:
diff --git a/nova/tests/unit/compute/test_api.py b/nova/tests/unit/compute/test_api.py
index 822bfc1a15..809ed3b295 100644
--- a/nova/tests/unit/compute/test_api.py
+++ b/nova/tests/unit/compute/test_api.py
@@ -1620,6 +1620,34 @@ class _ComputeAPIUnitTestMixIn(object):
                 self.compute_api.notifier, self.context, instance)
             destroy_mock.assert_called_once_with()
 
+    def test_delete_instance_while_booting_host_changes_lookup_fails(self):
+        """Tests the case where the instance become scheduled while being
+        destroyed but then the final lookup fails.
+        """
+        instance = self._create_instance_obj({'host': None})
+
+        with test.nested(
+            mock.patch.object(
+                self.compute_api, '_delete_while_booting',
+                side_effect=exception.ObjectActionError(
+                    action="delete", reason="reason")),
+            mock.patch.object(
+                self.compute_api, '_lookup_instance',
+                return_value=(None, None)),
+            mock.patch.object(self.compute_api, '_local_delete_cleanup')
+        ) as (
+            _delete_while_booting, _lookup_instance, _local_delete_cleanup
+        ):
+            self.compute_api._delete(
+                self.context, instance, 'delete', mock.NonCallableMock())
+
+            _delete_while_booting.assert_called_once_with(
+                self.context, instance)
+            _lookup_instance.assert_called_once_with(
+                self.context, instance.uuid)
+            _local_delete_cleanup.assert_called_once_with(
+                self.context, instance.uuid)
+
     @mock.patch.object(context, 'target_cell')
     @mock.patch.object(objects.InstanceMapping, 'get_by_instance_uuid',
                        side_effect=exception.InstanceMappingNotFound(