Set None explicitly to filter options.

When user is set to None in query, string value 'None'
was set instead of None.

Note: This fix is for mysql.
Fix for mongo is provided in:
https://review.openstack.org/#/c/260331/

Note2: Here, test for resource_id is removed as,
in sqlalchemy implementation, resource_id cannot be None.

Change-Id: I4bcf9283912e857a9902c62df25d0d5090670b10
Partial-Bug: #1388680

ceilometer/storage/impl_sqlalchemy.py

@@ -157,8 +157,12 @@ def make_query_from_filter(session, query, sample_filter, require_meter=True):
         else:
             query = query.filter(models.Sample.timestamp < ts_end)
     if sample_filter.user:
+        if sample_filter.user == 'None':
+            sample_filter.user = None
         query = query.filter(models.Resource.user_id == sample_filter.user)
     if sample_filter.project:
+        if sample_filter.project == 'None':
+            sample_filter.project = None
         query = query.filter(
             models.Resource.project_id == sample_filter.project)
     if sample_filter.resource:

ceilometer/tests/functional/storage/test_impl_sqlalchemy.py

@@ -28,6 +28,8 @@ from six.moves import reprlib
 
 from ceilometer.event.storage import impl_sqlalchemy as impl_sqla_event
 from ceilometer.event.storage import models
+from ceilometer.publisher import utils
+from ceilometer import sample
 from ceilometer.storage import impl_sqlalchemy
 from ceilometer.storage.sqlalchemy import models as sql_models
 from ceilometer.tests import base as test_base
@@ -190,3 +192,37 @@ class CapabilitiesTest(test_base.BaseTestCase):
         actual_capabilities = (impl_sqlalchemy.
                                Connection.get_storage_capabilities())
         self.assertEqual(expected_capabilities, actual_capabilities)
+
+
+@tests_db.run_with('sqlite', 'mysql', 'pgsql')
+class FilterQueryTestForMeters(scenarios.DBTestBase):
+    def prepare_data(self):
+            self.counters = []
+            c = sample.Sample(
+                'volume.size',
+                'gauge',
+                'GiB',
+                5,
+                user_id=None,
+                project_id=None,
+                resource_id='fake_id',
+                timestamp=datetime.datetime(2012, 9, 25, 10, 30),
+                resource_metadata={'display_name': 'test-volume',
+                                   'tag': 'self.counter',
+                                   },
+                source='test',
+            )
+
+            self.counters.append(c)
+            msg = utils.meter_message_from_counter(
+                c,
+                secret='not-so-secret')
+            self.conn.record_metering_data(msg)
+
+    def test_get_meters_by_user(self):
+        meters = list(self.conn.get_meters(user='None'))
+        self.assertEqual(1, len(meters))
+
+    def test_get_meters_by_project(self):
+        meters = list(self.conn.get_meters(project='None'))
+        self.assertEqual(1, len(meters))