Merge "Use correct metadata for metrics gathered from gnocchi"

cloudkitty/collector/gnocchi.py

@@ -385,6 +385,7 @@ class GnocchiCollector(collector.BaseCollector):
             'resource_type': resource_type,
             'start': start,
             'stop': end,
+            'use_history': True,
             'groupby': self.conf[metric_name]['groupby'],
             'search': self.extend_filter(*query_parameters),
         }

cloudkitty/tests/collectors/test_gnocchi.py

@@ -211,7 +211,8 @@ class GnocchiCollectorAggregationOperationTest(tests.TestCase):
                     resource_type='resource_x',
                     search={'=': {'type': 'resource_x'}},
                     start=self.start, stop=self.end,
-                    granularity=3600
+                    granularity=3600,
+                    use_history=True
                 )
 
     def test_multiple_confs(self):

releasenotes/notes/add_warning_regarding_gnocchi_version-99d5213c35950e39.yaml

@@ -0,0 +1,14 @@
+---
+fixes:
+  - |
+    CloudKitty will always use the correct metadata for the
+    processing and reprocessing jobs. This means, we always use
+    the metadata for the timestamp that we are collecting at
+    Gnocchi backend.This is achieved with the use of
+    ``use_history=true`` in Gnocchi, which was released under
+    `version 4.5.0 <https://github.com/gnocchixyz/gnocchi/releases/tag/4.5.0>`__.
+    Before that release, the ``aggregates`` API would only return
+    the latest metadata for the resource of the metric being handled.
+    Therefore, for CloudKitty processing and reprocessing, we would
+    always have the possibility of using the wrong attribute version
+    to rate the computing resources.