Exclude on maintenance reserved_hosts for host_failure recovery

masakari-engine considers reserved_hosts which are under maintenance
for host failure recovery when recovery_method is reserved_host,
auto_priority or rh_priority and passes it to workflow for processing.

If the reserved_host is under maintenance then it should not be used
for evacuating the instances for host_failure recovery.

This patch excludes reserved_hosts which are on maintenance for
host_failure recovery by filtering host_list with
'on_maintenance'=False.

Closes-Bug: #1697902
Change-Id: Ie6beff110d03b67d6f5d8694603816c0db017660

masakari/engine/manager.py

@@ -154,7 +154,9 @@ class MasakariManager(manager.Manager):
                 reserved_host_list = objects.HostList.get_all(
                     context, filters={
                         'failover_segment_id': host_obj.failover_segment_id,
-                        'reserved': True})
+                        'reserved': True,
+                        'on_maintenance': False
+                        })
 
             try:
                 self.driver.execute_host_failure(

masakari/tests/unit/db/test_db_api.py

@@ -296,6 +296,27 @@ class HostsTestCase(test.TestCase, ModelsObjectComparatorMixin):
             sort_dirs=['asc'])
         self._assertEqualListsOfObjects([hosts[1]], real_host, ignored_keys)
 
+    def test_host_get_all_by_filter_on_maintenance(self):
+        for p in self._get_fake_values_list():
+            # create temporary reserved_hosts, all are on maintenance
+            self._create_host(p)
+
+        # create one more reserved_host which is not on maintenance
+        temp_host = self._get_fake_values()
+        temp_host['on_maintenance'] = False
+        self._create_host(temp_host)
+
+        ignored_keys = ['deleted', 'created_at', 'updated_at', 'deleted_at',
+                        'id', 'failover_segment']
+        real_host = db.host_get_all_by_filters(
+            context=self.ctxt,
+            filters={'on_maintenance': False},
+            marker=1,
+            limit=1,
+            sort_keys=['id'],
+            sort_dirs=['asc'])
+        self._assertEqualListsOfObjects([temp_host], real_host, ignored_keys)
+
     def test_host_not_found(self):
         self._create_host(self._get_fake_values())
         self.assertRaises(exception.HostNotFound,

masakari/tests/unit/engine/test_engine_mgr.py

@@ -303,6 +303,9 @@ class EngineManagerUnitTestCase(test.NoDBTestCase):
             fake_host.name, fake_host.failover_segment.recovery_method,
             notification.notification_uuid,
             reserved_host_list=reserved_host_list)
+        mock_get_all.assert_called_once_with(self.context, filters={
+            'failover_segment_id': fake_host.failover_segment.uuid,
+            'reserved': True, 'on_maintenance': False})
 
     @mock.patch.object(host_obj.Host, "get_by_uuid")
     @mock.patch.object(host_obj.Host, "save")