Fix handling of Pool NS changes1.0.0.0rc21.0.0

Closes-Bug: #1500798

Change-Id: Ie697f35a523a63617ba386f0dcde63600ce5dac6
(cherry picked from commit c59a2a012e61a80ea4d985db04ac29a582c745d1)

2 files changed, 47 insertions, 8 deletions

diff --git a/designate/central/service.py b/designate/central/service.py
index 7c0412c5..c0cde389 100644
--- a/designate/central/service.py
+++ b/designate/central/service.py
@@ -609,13 +609,22 @@ class Service(service.RPCService, service.Service):
     def _add_ns(self, context, zone, ns_record):
         # Get NS recordset
         # If the zone doesn't have an NS recordset yet, create one
-        try:
-            ns_recordset = self.find_recordset(
-                context, criterion={'domain_id': zone['id'], 'type': "NS"})
+        recordsets = self.find_recordsets(
+            context, criterion={'domain_id': zone['id'], 'type': "NS"}
+        )
 
-        except exceptions.RecordSetNotFound:
+        managed = []
+        for rs in recordsets:
+            if rs.managed:
+                managed.append(rs)
+
+        if len(managed) == 0:
             self._create_ns(context, zone, [ns_record])
             return
+        elif len(managed) != 1:
+            raise exceptions.RecordSetNotFound("No valid recordset found")
+
+        ns_recordset = managed[0]
 
         # Add new record to recordset based on the new nameserver
         ns_recordset.records.append(
diff --git a/designate/tests/unit/test_central/test_basic.py b/designate/tests/unit/test_central/test_basic.py
index 42c90b90..a6763861 100644
--- a/designate/tests/unit/test_central/test_basic.py
+++ b/designate/tests/unit/test_central/test_basic.py
@@ -677,9 +677,11 @@ class CentralDomainTestCase(CentralBasic):
 
     def test__add_ns_creation(self):
         self.service._create_ns = Mock()
-        self.service.find_recordset = Mock(
-            side_effect=exceptions.RecordSetNotFound
+
+        self.service.find_recordsets = Mock(
+            return_value=[]
         )
+
         self.service._add_ns(
             self.context,
             RoObject(id='1'),
@@ -690,9 +692,37 @@ class CentralDomainTestCase(CentralBasic):
 
     def test__add_ns(self):
         self.service._update_recordset_in_storage = Mock()
-        self.service.find_recordset = Mock(
-            return_value=RoObject(records=[])
+
+        recordsets = [
+            RoObject(records=[], managed=True)
+        ]
+        self.service.find_recordsets = Mock(
+            return_value=recordsets
+        )
+
+        self.service._add_ns(
+            self.context,
+            RoObject(id='1'),
+            RoObject(name='bar')
         )
+        ctx, zone, rset = \
+            self.service._update_recordset_in_storage.call_args[0]
+        self.assertEqual(len(rset.records), 1)
+        self.assertTrue(rset.records[0].managed)
+        self.assertEqual(rset.records[0].data.name, 'bar')
+
+    def test__add_ns_with_other_ns_rs(self):
+        self.service._update_recordset_in_storage = Mock()
+
+        recordsets = [
+            RoObject(records=[], managed=True),
+            RoObject(records=[], managed=False)
+        ]
+
+        self.service.find_recordsets = Mock(
+            return_value=recordsets
+        )
+
         self.service._add_ns(
             self.context,
             RoObject(id='1'),