Secondary zone loops AXFR transfer during zone creation

When we create a secondary zone, AXFR transfer loops indefinitely.
Normally, only one xfr should be performed.
Due to AXFR loop the zone changes status from active to pending all the time.

Co-Authored-By: ZhouHeng <zhouhenglc@inspur.com>
Closes-Bug: 1856442
Change-Id: I0e0d138049e6d4c31dea3cc6768cc15e59a5942c

designate/central/service.py

@@ -821,7 +821,9 @@ class Service(service.RPCService):
         self.worker_api.create_zone(context, zone)
 
         if zone.type == 'SECONDARY':
-            self.worker_api.perform_zone_xfr(context, zone)
+            xfr_zone = copy.deepcopy(zone)
+            xfr_zone.obj_reset_changes(recursive=True)
+            self.worker_api.perform_zone_xfr(context, xfr_zone)
 
         # If zone is a superzone, update subzones
         # with new parent IDs

designate/objects/base.py

@@ -136,7 +136,7 @@ class DesignateObject(base.VersionedObject):
                 name == 'VERSION' or
                 name == 'fields'):
             raise AttributeError(
-                "Designate object '%(type)s' has no"
+                "Designate object '%(type)s' has no "
                 "attribute '%(name)s'" % {
                     'type': self.obj_name(),
                     'name': name,

designate/tests/unit/test_central/test_basic.py

@@ -1609,6 +1609,42 @@ class CentralZoneTestCase(CentralBasic):
             refresh_time = central_service._generate_soa_refresh_interval()
             self.assertEqual(3563, refresh_time)
 
+    @patch.object(objects.Zone, 'obj_reset_changes')
+    def test_create_secondary_zone(self, mock_obj_reset_changes):
+        self.service._enforce_zone_quota = mock.Mock()
+        self.service._create_zone_in_storage = mock.Mock(
+            return_value=objects.Zone(name='example.com.', type='SECONDARY'))
+        self.service._is_valid_zone_name = mock.Mock()
+        self.service._is_valid_ttl = mock.Mock()
+        self.service._is_subzone = mock.Mock(return_value=False)
+        self.service._is_superzone = mock.Mock(return_value=[])
+        self.service.storage.get_pool.return_value = RoObject(
+            ns_records=[RoObject()])
+        self.useFixture(
+            fixtures.MockPatchObject(
+                self.service.storage,
+                'find_pools',
+                return_value=objects.PoolList.from_list(
+                    [
+                        {'id': '94ccc2c1-d751-44fe-b57f-8894c9f5c842'}
+                    ]
+                )
+            )
+        )
+        output = self.service.create_zone(
+            self.context,
+            objects.Zone(
+                tenant_id='1',
+                name='example.com.',
+                ttl=60,
+                pool_id=CentralZoneTestCase.pool__id,
+                refresh=0,
+                type='SECONDARY'
+            )
+        )
+        self.assertEqual('example.com.', output.name)
+        mock_obj_reset_changes.assert_called_once_with(recursive=True)
+
 
 class IsSubzoneTestCase(CentralBasic):
     def setUp(self):