Fix YAMLAdapter when optional attributes are missing

So far, using YAMLAdapter in pools.yaml context, without providing all
of the pools.yaml attributes altogether, failed because of YAMLAdapter.

An example could be an end user who wouldn't like to deploy catalog
zones in its pools and therefore would drop that attribute from the
pools.yaml file, like in
designate/tests/resources/pools_yaml/multiple-pools.yaml.

Running any designate-manage pool command on a file without all of the
pools.yaml attributes will fail with the following error message:

designate.exceptions.AdapterNotFound:
Adapter for None to format YAML not found

This patch fixes it.

Closes-Bug: #2064720
Change-Id: I214cfc05a834d97a61d0236ab223470631bfc405

designate/objects/adapters/yaml/base.py

@@ -49,6 +49,10 @@ class YAMLAdapter(base.DesignateAdapter):
                 # if not, move on
                 new_obj = getattr(obj, key, None)
                 obj_key = key
+
+            if new_obj is None:
+                continue
+
             # Check if this item is a relation (another DesignateObject that
             # will need to be converted itself
             if hasattr(obj.FIELDS.get(obj_key, {}), 'objname'):

designate/tests/functional/manage/test_pool.py

@@ -68,6 +68,21 @@ class ManagePoolTestCase(designate.tests.functional.TestCase):
             'Default PowerDNS 4 Pool', ''.join(self.command.output_message)
         )
 
+    def test_show_config_catalog_zone(self):
+        self.command._setup()
+        self.command._create_pool(get_pools('pools-catalog-zone.yaml')[0])
+
+        pool_id = self.central_service.find_pool(
+            self.admin_context, {'name': 'default'}).id
+
+        self.command.show_config(pool_id)
+
+        self.print_result.assert_called_once()
+        self.assertIn('Pool Configuration', self.command.output_message[1])
+        self.assertIn(
+            'Default PowerDNS 4 Pool', ''.join(self.command.output_message)
+        )
+
     @mock.patch.object(service.Service, 'find_pool',
                        side_effect=oslo_messaging.MessagingTimeout())
     def test_show_config_rpc_timeout(self, mock_find_pool):

designate/tests/resources/pools_yaml/pools-catalog-zone.yaml

@@ -0,0 +1,36 @@
+---
+
+- name: default
+  description: Default PowerDNS 4 Pool
+
+  attributes:
+    type: internal
+
+  ns_records:
+    - hostname: ns1-1.example.org.
+      priority: 1
+    - hostname: ns1-2.example.org.
+      priority: 2
+
+  nameservers:
+    - host: 192.0.2.2
+      port: 53
+    - host: 192.0.2.3
+      port: 53
+
+  targets:
+    - type: pdns4
+      description: PowerDNS 4 Server
+      masters:
+        - host: 192.0.2.1
+          port: 5354
+      options:
+        api_endpoint: http://192.0.2.1:8081
+        api_token: api_key
+  also_notifies:
+   - host: 192.0.2.4
+     port: 53
+
+  catalog_zone:
+    catalog_zone_fqdn: example.org.
+    catalog_zone_refresh: '60'

designate/tests/resources/pools_yaml/pools.yaml

@@ -30,7 +30,3 @@
   also_notifies:
    - host: 192.0.2.4
      port: 53
-
-  catalog_zone:
-    catalog_zone_fqdn: example.org.
-    catalog_zone_refresh: '60'

releasenotes/notes/Fix-designate-manage-pool-update-with-missing-attributes-3037b2dad30f84e2.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    So far, the yaml Adapter made every designate-manage pool command
+    fail if the pools.yaml file was missing any of the pool attributes.
+    This patch makes the adapter to continue without raising any error.