Merge "Remove hosts if can't find hosts in host agrregate"

watcher/decision_engine/scope/compute.py

@@ -167,6 +167,7 @@ class ComputeScope(base.BaseScope):
         instance_metadata = []
         projects_to_exclude = []
         compute_scope = []
+        found_nothing_flag = False
         model_hosts = list(cluster_model.get_all_compute_nodes().keys())
 
         if not self.scope:
@@ -182,9 +183,13 @@ class ComputeScope(base.BaseScope):
             if 'host_aggregates' in rule:
                 self._collect_aggregates(rule['host_aggregates'],
                                          allowed_nodes)
+                if not allowed_nodes:
+                    found_nothing_flag = True
             elif 'availability_zones' in rule:
                 self._collect_zones(rule['availability_zones'],
                                     allowed_nodes)
+                if not allowed_nodes:
+                    found_nothing_flag = True
             elif 'exclude' in rule:
                 self.exclude_resources(
                     rule['exclude'], instances=instances_to_exclude,
@@ -195,6 +200,10 @@ class ComputeScope(base.BaseScope):
         instances_to_exclude = set(instances_to_exclude)
         if allowed_nodes:
             nodes_to_remove = set(model_hosts) - set(allowed_nodes)
+        # This branch means user set host_aggregates and/or availability_zones
+        # but can't find any nodes, so we should remove all nodes.
+        elif found_nothing_flag:
+            nodes_to_remove = set(model_hosts)
         nodes_to_remove.update(nodes_to_exclude)
 
         self.remove_nodes_from_model(nodes_to_remove, cluster_model)

watcher/tests/decision_engine/scope/fake_scopes.py

@@ -47,3 +47,9 @@ fake_scope_2 = [{'storage': [{'availability_zones': [{'name': 'zone_0'}]},
                              ]}]
                  }
                 ]
+
+fake_scope_3 = [{'compute': [{'host_aggregates': [{'id': '1'}]},
+                             {'exclude': []
+                              }]
+                 }
+                ]

watcher/tests/decision_engine/scope/test_compute.py

@@ -281,3 +281,16 @@ class TestComputeScope(base.TestCase):
             model.get_instance_by_uuid('INSTANCE_0').watcher_exclude)
         self.assertTrue(
             model.get_instance_by_uuid('INSTANCE_1').watcher_exclude)
+
+    @mock.patch.object(nova_helper.NovaHelper, 'get_aggregate_detail')
+    @mock.patch.object(nova_helper.NovaHelper, 'get_aggregate_list')
+    def test_get_scoped_model_with_hostaggregate_null(
+            self, mock_list, mock_detail):
+        cluster = self.fake_cluster.generate_scenario_1()
+        audit_scope = fake_scopes.fake_scope_3
+        mock_list.return_value = [mock.Mock(id=i,
+                                            name="HA_{0}".format(i))
+                                  for i in range(2)]
+        model = compute.ComputeScope(audit_scope, mock.Mock(),
+                                     osc=mock.Mock()).get_scoped_model(cluster)
+        self.assertEqual(0, len(model.edges()))