Gnocchi: don't fail to create valid alarm

When the Gnocchi resource or metric doesn't exists yet, we refuse
to create the alarm and return a confusing 404.

This change returns 200, in such case and removes the need to have the
Gnocchi resource and metric existing, we just trust that the id/name
provided by the use will exists.

Depends-On: I810897e750c4b5a42bb3ada2f8a2488dbee609f4
Change-Id: I404daf0c30d4b3ced239a94b98d8a62bad71a6b6

aodh/api/controllers/v2/alarm_rules/gnocchi.py

@@ -99,26 +99,6 @@ class MetricOfResourceRule(AlarmGnocchiThresholdRule):
                                        'resource_type'])
         return rule
 
-    @classmethod
-    def validate_alarm(cls, alarm):
-        super(MetricOfResourceRule,
-              cls).validate_alarm(alarm)
-
-        conf = pecan.request.cfg
-        gnocchi_client = client.Client(
-            '1', keystone_client.get_session(conf),
-            interface=conf.service_credentials.interface,
-            region_name=conf.service_credentials.region_name)
-
-        rule = alarm.gnocchi_resources_threshold_rule
-        try:
-            gnocchi_client.resource.get(rule.resource_type,
-                                        rule.resource_id)
-        except exceptions.ClientException as e:
-            raise base.ClientSideError(e.message, status_code=e.code)
-        except Exception as e:
-            raise GnocchiUnavailable(e)
-
 
 class AggregationMetricByResourcesLookupRule(AlarmGnocchiThresholdRule):
     metric = wsme.wsattr(wtypes.text, mandatory=True)
@@ -176,6 +156,11 @@ class AggregationMetricByResourcesLookupRule(AlarmGnocchiThresholdRule):
                 needed_overlap=0,
                 resource_type=rule.resource_type)
         except exceptions.ClientException as e:
+            if e.code == 404:
+                # NOTE(sileht): We are fine here, we just want to ensure the
+                # 'query' payload is valid for Gnocchi If the metric
+                # doesn't exists yet, it doesn't matter
+                return
             raise base.ClientSideError(e.message, status_code=e.code)
         except Exception as e:
             raise GnocchiUnavailable(e)

aodh/evaluator/gnocchi.py

@@ -14,6 +14,7 @@
 # under the License.
 
 from gnocchiclient import client
+from gnocchiclient import exceptions
 from oslo_log import log
 from oslo_serialization import jsonutils
 
@@ -61,9 +62,12 @@ class GnocchiResourceThresholdEvaluator(GnocchiBase):
                 start=start, stop=end,
                 resource_id=rule['resource_id'],
                 aggregation=rule['aggregation_method'])
+        except exceptions.NotFound:
+            LOG.debug('metric %s or resource %s does not exists',
+                      rule['metric'], rule['resource_id'])
+            return []
         except Exception as e:
-            LOG.warning(_LW('alarm stats retrieval failed: %s'),
+            LOG.warning(_LW('alarm stats retrieval failed: %s'), e)
-                        e)
             return []
 
 
@@ -83,6 +87,9 @@ class GnocchiAggregationMetricsThresholdEvaluator(GnocchiBase):
                 start=start, stop=end,
                 aggregation=rule['aggregation_method'],
                 needed_overlap=0)
+        except exceptions.NotFound:
+            LOG.debug('metrics %s does not exists', rule['metrics'])
+            return []
         except Exception as e:
             LOG.warning(_LW('alarm stats retrieval failed: %s'), e)
             return []
@@ -107,6 +114,9 @@ class GnocchiAggregationResourcesThresholdEvaluator(GnocchiBase):
                 aggregation=rule['aggregation_method'],
                 needed_overlap=0,
             )
+        except exceptions.NotFound:
+            LOG.debug('metric %s does not exists', rule['metric'])
+            return []
         except Exception as e:
             LOG.warning(_LW('alarm stats retrieval failed: %s'), e)
             return []

aodh/tests/functional/api/v2/test_alarm_scenarios.py

@@ -2569,9 +2569,6 @@ class TestAlarmsRuleGnocchi(TestAlarmsBase):
             c.capabilities.list.return_value = {
                 'aggregation_methods': ['count']}
             self.post_json('/alarms', params=json, headers=self.auth_headers)
-            expected = mock.call.resource.get(
-                "instance", "209ef69c-c10c-4efb-90ff-46f4b2d90d2e")
-            self.assertIn(expected, c.mock_calls)
 
         alarms = list(self.alarm_conn.get_alarms(enabled=False))
         self.assertEqual(1, len(alarms))