Handles input aggregate for statistics

When statistics API is used with custom
aggregates as input, there is an attribute
error in client as it expects an aggregate
dict in response.

This adds the aggregate dict in response
when input has an aggregate function.

Change-Id: Ide13f5d16b6e4ef11cdcb9c98d85200efaf0cb91

ceilosca/ceilometer/storage/impl_monasca.py

@@ -608,6 +608,13 @@ class Connection(base.Connection):
                 del stats_dict['timestamp']
                 if 'count' in stats_dict:
                     stats_dict['count'] = int(stats_dict['count'])
+                if aggregate:
+                    stats_dict['aggregate'] = {}
+                    for a in aggregate:
+                        key = '%s%s' % (a.func,
+                                        '/%s' % a.param if a.param else '')
+                        stats_dict['aggregate'][key] = stats_dict.get(key)
+
                 yield api_models.Statistics(
                     unit=stats['dimensions'].get('unit'),
                     period=period,

ceilosca/ceilometer/tests/unit/storage/test_impl_monasca.py

@@ -22,6 +22,7 @@ from oslo_utils import timeutils
 from oslotest import base
 
 import ceilometer
+from ceilometer.api.controllers.v2.meters import Aggregate
 import ceilometer.storage as storage
 from ceilometer.storage import impl_monasca
 
@@ -609,9 +610,12 @@ class MeterStatisticsTest(base.BaseTestCase):
 
             sf = storage.SampleFilter()
             sf.meter = "image"
+            aggregate = Aggregate()
+            aggregate.func = 'min'
             sf.start_timestamp = timeutils.parse_isotime(
                 '2014-10-24T12:12:42').replace(tzinfo=None)
-            stats = list(conn.get_meter_statistics(sf, period=30))
+            stats = list(conn.get_meter_statistics(sf, aggregate=[aggregate],
+                                                   period=30))
 
             self.assertEqual(2, len(stats))
             self.assertEqual('gb', stats[0].unit)
@@ -623,6 +627,8 @@ class MeterStatisticsTest(base.BaseTestCase):
                              stats[0].period_end.isoformat())
             self.assertEqual('2014-10-24T12:52:42',
                              stats[1].period_end.isoformat())
+            self.assertIsNotNone(stats[0].as_dict().get('aggregate'))
+            self.assertEqual({u'min': 0.008}, stats[0].as_dict()['aggregate'])
 
 
 class CapabilitiesTest(base.BaseTestCase):