Ignore fake nodes in the power sync loop

Fake nodes have power_state None and the power interface returns None as
well. Currently we make an update every loop, even though the values are
the same. This change fixes it.

Change-Id: I5227c058f3f6e1583b54a1cbc7edc6d42e20ae53

2 files changed, 13 insertions, 2 deletions

diff --git a/ironic/conductor/manager.py b/ironic/conductor/manager.py
index 4935c5110..24305915a 100644
--- a/ironic/conductor/manager.py
+++ b/ironic/conductor/manager.py
@@ -3656,7 +3656,8 @@ def do_sync_power_state(task, count):
     # Also make sure to cache the current boot_mode and secure_boot states
     utils.node_cache_boot_mode(task)
 
-    if node.power_state and node.power_state == power_state:
+    if ((node.power_state and node.power_state == power_state)
+            or (node.power_state is None and power_state is None)):
         # No action is needed
         return 0
 
@@ -3666,7 +3667,8 @@ def do_sync_power_state(task, count):
     node = task.node
 
     # Repeat all checks with exclusive lock to avoid races
-    if node.power_state and node.power_state == power_state:
+    if ((node.power_state and node.power_state == power_state)
+            or (node.power_state is None and power_state is None)):
         # Node power state was updated to the correct value
         return 0
     elif node.provision_state in SYNC_EXCLUDED_STATES or node.maintenance:
diff --git a/ironic/tests/unit/conductor/test_manager.py b/ironic/tests/unit/conductor/test_manager.py
index da1d7574d..542f224bf 100644
--- a/ironic/tests/unit/conductor/test_manager.py
+++ b/ironic/tests/unit/conductor/test_manager.py
@@ -4985,6 +4985,15 @@ class ManagerDoSyncPowerStateTestCase(db_base.DbTestCase):
         self.assertFalse(node_power_action.called)
         self.assertFalse(self.task.upgrade_lock.called)
 
+    def test_state_unchanged_for_fake_node(self, node_power_action):
+        self._do_sync_power_state(None, None)
+
+        self.power.validate.assert_called_once_with(self.task)
+        self.power.get_power_state.assert_called_once_with(self.task)
+        self.assertIsNone(self.node.power_state)
+        self.assertFalse(node_power_action.called)
+        self.assertFalse(self.task.upgrade_lock.called)
+
     @mock.patch.object(nova, 'power_update', autospec=True)
     def test_state_not_set(self, mock_power_update, node_power_action):
         self._do_sync_power_state(None, states.POWER_ON)