Fix uniform airflow strategy config parameter

'datasource' should be 'datasources'

Change-Id: I2bd183e020298a93029f38008619a5bebaed3de4

watcher/decision_engine/strategy/strategies/uniform_airflow.py

@@ -90,12 +90,6 @@ class UniformAirflow(base.BaseStrategy):
         super(UniformAirflow, self).__init__(config, osc)
         # The migration plan will be triggered when the airflow reaches
         # threshold
-        self.meter_name_airflow = self.METRIC_NAMES[
-            self.config.datasource]['host_airflow']
-        self.meter_name_inlet_t = self.METRIC_NAMES[
-            self.config.datasource]['host_inlet_temp']
-        self.meter_name_power = self.METRIC_NAMES[
-            self.config.datasource]['host_power']
         self._period = self.PERIOD
 
     @classmethod
@@ -158,11 +152,14 @@ class UniformAirflow(base.BaseStrategy):
     @classmethod
     def get_config_opts(cls):
         return [
-            cfg.StrOpt(
-                "datasource",
-                help="Data source to use in order to query the needed metrics",
-                default="gnocchi",
-                choices=["ceilometer", "gnocchi"])
+            cfg.ListOpt(
+                "datasources",
+                help="Datasources to use in order to query the needed metrics."
+                     " If one of strategy metric isn't available in the first"
+                     " datasource, the next datasource will be chosen.",
+                item_type=cfg.types.String(choices=['gnocchi', 'ceilometer',
+                                                    'monasca']),
+                default=['gnocchi', 'ceilometer', 'monasca']),
         ]
 
     def get_available_compute_nodes(self):
@@ -317,6 +314,13 @@ class UniformAirflow(base.BaseStrategy):
         if self.compute_model.stale:
             raise wexc.ClusterStateStale()
 
+        self.meter_name_airflow = self.METRIC_NAMES[
+            self.datasource_backend.NAME]['host_airflow']
+        self.meter_name_inlet_t = self.METRIC_NAMES[
+            self.datasource_backend.NAME]['host_inlet_temp']
+        self.meter_name_power = self.METRIC_NAMES[
+            self.datasource_backend.NAME]['host_power']
+
         LOG.debug(self.compute_model.to_string())
 
     def do_execute(self):

watcher/tests/decision_engine/model/ceilometer_metrics.py

@@ -20,6 +20,8 @@ import oslo_utils
 
 
 class FakeCeilometerMetrics(object):
+    NAME = 'ceilometer'
+
     def __init__(self):
         self.emptytype = ""
 

watcher/tests/decision_engine/model/gnocchi_metrics.py

@@ -15,6 +15,8 @@ import oslo_utils
 
 
 class FakeGnocchiMetrics(object):
+    NAME = 'gnocchi'
+
     def __init__(self):
         self.emptytype = ""
 

watcher/tests/decision_engine/strategy/strategies/test_uniform_airflow.py

@@ -71,7 +71,8 @@ class TestUniformAirflow(base.TestCase):
 
         self.m_model.return_value = model_root.ModelRoot()
         self.m_datasource.return_value = mock.Mock(
-            statistic_aggregation=self.fake_metrics.mock_get_statistics)
+            statistic_aggregation=self.fake_metrics.mock_get_statistics,
+            NAME=self.fake_metrics.NAME)
         self.strategy = strategies.UniformAirflow(
             config=mock.Mock(datasource=self.datasource))
         self.strategy.input_parameters = utils.Struct()
@@ -83,6 +84,7 @@ class TestUniformAirflow(base.TestCase):
         self.strategy.threshold_inlet_t = 28
         self.strategy.threshold_power = 350
         self._period = 300
+        self.strategy.pre_execute()
 
     def test_calc_used_resource(self):
         model = self.fake_cluster.generate_scenario_7_with_2_nodes()