Do not try to refresh vips on OVN LB that will be deleted

When there are multiple listeners with different protocols
configured on OVN LB, and one of listeners needs to be deleted,
there is no need to refresh vips on given OVN LB.
If there are no listners withing same protocol left the given OVN
LB could be deleted and there is no need to refresh vips then.

Change-Id: If15f817617facade10005878c8dfc7f467ce75a9
Closes-Bug: 1866087

ovn_octavia_provider/driver.py

@@ -316,6 +316,7 @@ class OvnProviderHelper(object):
 
     def _clean_lb_if_empty(self, ovn_lb, lb_id, external_ids):
         commands = []
+        lb_to_delete = False
         if OvnProviderHelper._is_lb_empty(external_ids):
             # Verify if its only OVN LB defined. If so - leave with
             # undefined protocol. If there is different for other protocol
@@ -328,10 +329,11 @@ class OvnProviderHelper(object):
                 commands.append(
                     self.ovn_nbdb_api.db_set(
                         'Load_Balancer', ovn_lb.uuid, ('protocol', [])))
-            else:
+            elif len(defined_ovn_lbs) > 1:
                 # Delete the lb.
                 commands.append(self.ovn_nbdb_api.lb_del(ovn_lb.uuid))
-        return commands
+                lb_to_delete = True
+        return (commands, lb_to_delete)
 
     def lb_delete_lrp_assoc_handler(self, row):
         try:
@@ -1233,11 +1235,14 @@ class OvnProviderHelper(object):
 
                 # Set LB protocol to undefined only if there are no more
                 # listeners and pools defined in the LB.
-                commands.extend(
-                    self._clean_lb_if_empty(
-                        ovn_lb, listener['loadbalancer_id'], external_ids))
-                commands.extend(
-                    self._refresh_lb_vips(ovn_lb.uuid, external_ids))
+                cmds, lb_to_delete = self._clean_lb_if_empty(
+                    ovn_lb, listener['loadbalancer_id'], external_ids)
+                commands.extend(cmds)
+                # Do not refresh vips if OVN LB for given protocol
+                # has pending delete operation.
+                if not lb_to_delete:
+                    commands.extend(
+                        self._refresh_lb_vips(ovn_lb.uuid, external_ids))
                 self._execute_commands(commands)
             except Exception:
                 LOG.exception(EXCEPTION_MSG, "deletion of listener")
@@ -1444,7 +1449,7 @@ class OvnProviderHelper(object):
 
             commands.extend(
                 self._clean_lb_if_empty(
-                    ovn_lb, pool['loadbalancer_id'], external_ids))
+                    ovn_lb, pool['loadbalancer_id'], external_ids)[0])
             self._execute_commands(commands)
 
             if listener_id:

ovn_octavia_provider/tests/unit/test_driver.py

@@ -1397,7 +1397,12 @@ class TestOvnProviderHelper(TestOvnOctaviaBase):
         self.helper.ovn_nbdb_api.lb_del.assert_not_called()
 
     @mock.patch.object(ovn_driver.OvnProviderHelper, '_is_lb_empty')
-    def test_listener_delete_ovn_lb_empty_lb_empty(self, lb_empty):
+    def test_listener_delete_ovn_lb_empty_octavia_lb_empty(self, lb_empty):
+        """That test situation when the OVN and Octavia LBs are empty.
+
+           That test situation when both OVN and Octavia LBs are empty,
+           but we cannot remove OVN LB row.
+        """
         lb_empty.return_value = True
         self.helper.listener_delete(self.listener)
         self.helper.ovn_nbdb_api.db_remove.assert_called_once_with(
@@ -1410,10 +1415,13 @@ class TestOvnProviderHelper(TestOvnOctaviaBase):
                       ('protocol', []))])
 
     @mock.patch.object(ovn_driver.OvnProviderHelper, '_is_lb_empty')
-    def test_listener_delete_ovn_lb_empty_lb_not_empty(self, lb_empty):
+    def test_listener_delete_ovn_lb_empty_octavia_lb_not_empty(self, lb_empty):
+        """We test if we can remove one LB with not used protocol"""
+        ovn_lb_udp = copy.copy(self.ovn_lb)
+        ovn_lb_udp.protocol = ['udp']
         self.mock_find_ovn_lbs.stop()
         self.helper.ovn_nbdb_api.db_find_rows.return_value.\
-            execute.side_effect = [[self.ovn_lb], []]
+            execute.side_effect = [[self.ovn_lb], [self.ovn_lb, ovn_lb_udp]]
         lb_empty.return_value = True
         self.helper.listener_delete(self.listener)
         self.helper.ovn_nbdb_api.db_remove.assert_called_once_with(
@@ -1421,6 +1429,10 @@ class TestOvnProviderHelper(TestOvnOctaviaBase):
             'external_ids', 'listener_%s' % self.listener_id)
         self.helper.ovn_nbdb_api.lb_del.assert_called_once_with(
             self.ovn_lb.uuid)
+        # Validate that the vips column hasn't been touched, because
+        # in previous command we remove the LB, so there is no need
+        # to update it.
+        self.helper.ovn_nbdb_api.db_set.assert_not_called()
 
     def test_pool_create(self):
         status = self.helper.pool_create(self.pool)
@@ -1627,9 +1639,10 @@ class TestOvnProviderHelper(TestOvnOctaviaBase):
 
     @mock.patch.object(ovn_driver.OvnProviderHelper, '_is_lb_empty')
     def test_pool_delete_ovn_lb_empty_lb_not_empty(self, lb_empty):
+        ovn_lb_udp = copy.copy(self.ovn_lb)
         self.mock_find_ovn_lbs.stop()
         self.helper.ovn_nbdb_api.db_find_rows.return_value.\
-            execute.side_effect = [[self.ovn_lb], []]
+            execute.side_effect = [[self.ovn_lb], [self.ovn_lb, ovn_lb_udp]]
         lb_empty.return_value = True
         self.helper.pool_delete(self.pool)
         self.helper.ovn_nbdb_api.db_remove.assert_called_once_with(