Don't print traceback if standard attr is missing on update

If northd is very busy, it may happen port is deleted when handling an
LSP down event causing standard attribute being gone when bumping ovn
revision number. This is because the port is set down in SB DB first and
then northd propagates that to NB DB, and then the event is emited.

This patch just makes sure the traceback is not printed in case this
happens.

TrivialFix
Closes-bug: #2069442

Depends-On: https://review.opendev.org/c/openstack/nova/+/925000
Change-Id: I7d21e4adc27fab411346e0458c92191e69ce6b30
Signed-off-by: Jakub Libosvar <[email protected]>
(cherry picked from commit 8ab385f)

Author: cubeek

neutron/plugins/ml2/drivers/ovn/mech_driver/mech_driver.py

@@ -786,6 +786,9 @@ def _ovn_update_port(self, plugin_context, port, original_port,
                     port['revision_number'] = db_port['revision_number']
                     self._ovn_update_port(plugin_context, port, original_port,
                                           retry_on_revision_mismatch=False)
+        except ovn_revision_numbers_db.StandardAttributeIDNotFound:
+            LOG.debug("Standard attribute was not found for port %s. It was "
+                      "possibly deleted concurrently.", port['id'])
 
     def create_port_postcommit(self, context):
         """Create a port.

neutron/tests/unit/plugins/ml2/drivers/ovn/mech_driver/test_mech_driver.py

@@ -2347,8 +2347,11 @@ def test_update_port_postcommit_live_migration_revision_mismatch_once(
                        '_is_port_provisioning_required', lambda *_: True)
     @mock.patch.object(mech_driver.OVNMechanismDriver, '_notify_dhcp_updated')
     @mock.patch.object(ovn_client.OVNClient, 'update_port')
-    def test_update_port_postcommit_revision_mismatch_not_after_live_migration(
-            self, mock_update_port, mock_notify_dhcp):
+    def _test_update_port_postcommit_with_exception(
+            self, mock_update_port, mock_notify_dhcp,
+            raised_exc,
+            resource_id_name,
+            **exc_extra_params):
         self.plugin.update_port_status = mock.Mock()
         self.plugin.get_port = mock.Mock(return_value=mock.MagicMock())
 
@@ -2366,10 +2369,12 @@ def test_update_port_postcommit_revision_mismatch_not_after_live_migration(
 
         fake_ctx = mock.Mock(current=fake_port, original=original_fake_port,
                              plugin_context=fake_context)
+
+        exc_params = exc_extra_params.copy()
+        exc_params[resource_id_name] = fake_port['id']
+
         mock_update_port.side_effect = [
-            ovn_exceptions.RevisionConflict(
-                resource_id=fake_port['id'],
-                resource_type=ovn_const.TYPE_PORTS),
+            raised_exc(**exc_params),
             None]
 
         self.mech_driver.update_port_postcommit(fake_ctx)
@@ -2379,6 +2384,20 @@ def test_update_port_postcommit_revision_mismatch_not_after_live_migration(
         self.assertEqual(1, mock_update_port.call_count)
         mock_notify_dhcp.assert_called_with(fake_port['id'])
 
+    def test_update_port_postcommit_revision_mismatch_not_after_live_migration(
+            self):
+        self._test_update_port_postcommit_with_exception(
+            raised_exc=ovn_exceptions.RevisionConflict,
+            resource_id_name='resource_id',
+            resource_type=ovn_const.TYPE_PORTS,
+        )
+
+    def test__ovn_update_port_missing_stdattribute(self):
+        """Make sure exception is handled."""
+        self._test_update_port_postcommit_with_exception(
+            raised_exc=ovn_revision_numbers_db.StandardAttributeIDNotFound,
+            resource_id_name='resource_uuid')
+
     def test_agent_alive_true(self):
         chassis_private = self._add_chassis_private(5)
         for agent_type in (ovn_const.OVN_CONTROLLER_AGENT,