Remove root device hint after delete_configuration

The root device hint is not guaranteed to be valid after raid
configuration in most cases, this could cause no matching device
found and fail the deployment. AgentRAID implementations can return
the correct root device hint from the create_configuration.

Change-Id: Iab97a16ef8ccea8186f0cc7a14b77d508804fc8d

ironic/drivers/modules/agent.py

@@ -808,6 +808,9 @@ class AgentRAID(base.RAIDInterface):
             returned from agent ramdisk on query of the status of command(s).
         :returns: None
         """
+        prop = task.node.properties
+        prop.pop('root_device', None)
+        task.node.properties = prop
         task.node.raid_config = {}
         task.node.save()
 

ironic/tests/unit/drivers/modules/test_agent.py

@@ -1952,11 +1952,13 @@ class AgentRAIDTestCase(db_base.DbTestCase):
         command = {'command_result': {'clean_result': 'foo'}}
         with task_manager.acquire(self.context, self.node.uuid) as task:
             task.node.raid_config = {'foo': 'bar'}
+            task.node.properties = {'root_device': {'wwn': 'fake wwn'}}
             raid_mgmt = agent.AgentRAID
             raid_mgmt._delete_configuration_final(task, command)
 
         self.node.refresh()
         self.assertEqual({}, self.node.raid_config)
+        self.assertEqual({}, self.node.properties)
 
     def test__delete_configuration_final_registered(
             self):

releasenotes/notes/raid-remove-root-hint-ec87efd18e894256.yaml

@@ -0,0 +1,10 @@
+---
+upgrade:
+  - |
+    Agent raid will remove the root device hint after the RAID configuration
+    is successfully deleted.
+fixes:
+  - |
+    Fixes the issue that root device hint is not removed after agent raid
+    interface has successfully deleted RAID configuration, the previous hint
+    is not guranteed to be valid thus will cause a deployment failed.