Add AggregateList.get_by_metadata() query method

This query method lets us pull aggregates by key, value,
or key and value.

Change-Id: I1425005f94e2ac22e7e07bc09c7305900a25ca4a

nova/objects/aggregate.py

@@ -417,10 +417,14 @@ def _get_by_host_from_db(context, host, key=None):
 
 
 @db_api.api_context_manager.reader
-def _get_by_metadata_key_from_db(context, key):
+def _get_by_metadata_from_db(context, key=None, value=None):
+    assert(key is not None or value is not None)
     query = context.session.query(api_models.Aggregate)
     query = query.join("_metadata")
-    query = query.filter(api_models.AggregateMetadata.key == key)
+    if key is not None:
+        query = query.filter(api_models.AggregateMetadata.key == key)
+    if value is not None:
+        query = query.filter(api_models.AggregateMetadata.value == value)
     query = query.options(contains_eager("_metadata"))
     query = query.options(joinedload("_hosts"))
 
@@ -433,7 +437,8 @@ class AggregateList(base.ObjectListBase, base.NovaObject):
     # Version 1.1: Added key argument to get_by_host()
     #              Aggregate <= version 1.1
     # Version 1.2: Added get_by_metadata_key
-    VERSION = '1.2'
+    # Version 1.3: Added get_by_metadata
+    VERSION = '1.3'
 
     fields = {
         'objects': fields.ListOfObjectsField('Aggregate'),
@@ -465,8 +470,20 @@ def get_by_host(cls, context, host, key=None):
 
     @base.remotable_classmethod
     def get_by_metadata_key(cls, context, key, hosts=None):
-        db_aggregates = _get_by_metadata_key_from_db(context, key=key)
+        db_aggregates = _get_by_metadata_from_db(context, key=key)
         if hosts is not None:
             db_aggregates = cls._filter_db_aggregates(db_aggregates, hosts)
         return base.obj_make_list(context, cls(context), objects.Aggregate,
                                   db_aggregates)
+
+    @base.remotable_classmethod
+    def get_by_metadata(cls, context, key=None, value=None):
+        """Return aggregates with a metadata key set to value.
+
+        This returns a list of all aggregates that have a metadata key
+        set to some value. If key is specified, then only values for
+        that key will qualify.
+        """
+        db_aggregates = _get_by_metadata_from_db(context, key=key, value=value)
+        return base.obj_make_list(context, cls(context), objects.Aggregate,
+                                  db_aggregates)

nova/tests/functional/db/test_aggregate.py

@@ -181,7 +181,7 @@ def test_aggregate_get_by_metadata_key_from_db(self):
         _create_aggregate(self.context,
                           values={'name': 'aggregate_3'},
                           metadata={'badkey': 'good'})
-        rl1 = aggregate_obj._get_by_metadata_key_from_db(self.context,
+        rl1 = aggregate_obj._get_by_metadata_from_db(self.context,
                                                      key='goodkey')
         self.assertEqual(2, len(rl1))
 
@@ -204,8 +204,8 @@ def test_aggregate_create_in_db_with_metadata(self):
                                                 metadata={'goodkey': 'good'})
         result = aggregate_obj._aggregate_get_from_db(self.context,
                                                       agg.id)
-        md = aggregate_obj._get_by_metadata_key_from_db(self.context,
-                                                        key='goodkey')
+        md = aggregate_obj._get_by_metadata_from_db(self.context,
+                                                    key='goodkey')
         self.assertEqual(len(md), 1)
         self.assertEqual(md[0]['id'], agg.id)
         self.assertEqual(result.name, fake_create_aggregate['name'])
@@ -538,3 +538,26 @@ def test_delete_host(self):
             result = aggregate_obj.Aggregate.get_by_id(self.context, i)
             compare_obj(self, agg, fake_agg)
             compare_obj(self, result, fake_agg)
+
+    def test_get_by_metadata(self):
+        agg = aggregate_obj.Aggregate.get_by_id(self.context, 1)
+        agg.update_metadata({'foo': 'bar'})
+
+        agg = aggregate_obj.Aggregate.get_by_id(self.context, 2)
+        agg.update_metadata({'foo': 'baz',
+                             'fu': 'bar'})
+
+        aggs = aggregate_obj.AggregateList.get_by_metadata(
+            self.context, key='foo', value='bar')
+        self.assertEqual(1, len(aggs))
+        self.assertEqual(1, aggs[0].id)
+
+        aggs = aggregate_obj.AggregateList.get_by_metadata(
+            self.context, value='bar')
+        self.assertEqual(2, len(aggs))
+        self.assertEqual(set([1, 2]), set([a.id for a in aggs]))
+
+    def test_get_by_metadata_from_db_assertion(self):
+        self.assertRaises(AssertionError,
+                          aggregate_obj._get_by_metadata_from_db,
+                          self.context)

nova/tests/unit/objects/test_aggregate.py

@@ -192,22 +192,22 @@ def test_by_host(self, mock_api_get_by_host):
         self.assertEqual(1, len(aggs))
         self.compare_obj(aggs[0], fake_aggregate, subs=SUBS)
 
-    @mock.patch('nova.objects.aggregate._get_by_metadata_key_from_db')
+    @mock.patch('nova.objects.aggregate._get_by_metadata_from_db')
     def test_get_by_metadata_key(self, mock_api_get_by_metadata_key):
         mock_api_get_by_metadata_key.return_value = [fake_aggregate]
         aggs = aggregate.AggregateList.get_by_metadata_key(
             self.context, 'this')
         self.assertEqual(1, len(aggs))
         self.compare_obj(aggs[0], fake_aggregate, subs=SUBS)
 
-    @mock.patch('nova.objects.aggregate._get_by_metadata_key_from_db')
+    @mock.patch('nova.objects.aggregate._get_by_metadata_from_db')
     def test_get_by_metadata_key_and_hosts_no_match(self, get_by_metadata_key):
         get_by_metadata_key.return_value = [fake_aggregate]
         aggs = aggregate.AggregateList.get_by_metadata_key(
             self.context, 'this', hosts=['baz'])
         self.assertEqual(0, len(aggs))
 
-    @mock.patch('nova.objects.aggregate._get_by_metadata_key_from_db')
+    @mock.patch('nova.objects.aggregate._get_by_metadata_from_db')
     def test_get_by_metadata_key_and_hosts_match(self, get_by_metadata_key):
         get_by_metadata_key.return_value = [fake_aggregate]
         aggs = aggregate.AggregateList.get_by_metadata_key(

nova/tests/unit/objects/test_objects.py

@@ -1057,7 +1057,7 @@ def obj_name(cls):
     'Agent': '1.0-c0c092abaceb6f51efe5d82175f15eba',
     'AgentList': '1.0-5a7380d02c3aaf2a32fc8115ae7ca98c',
     'Aggregate': '1.3-f315cb68906307ca2d1cca84d4753585',
-    'AggregateList': '1.2-fb6e19f3c3a3186b04eceb98b5dadbfa',
+    'AggregateList': '1.3-3ea55a050354e72ef3306adefa553957',
     'BandwidthUsage': '1.2-c6e4c779c7f40f2407e3d70022e3cd1c',
     'BandwidthUsageList': '1.2-5fe7475ada6fe62413cbfcc06ec70746',
     'BlockDeviceMapping': '1.19-407e75274f48e60a76e56283333c9dbc',