Allow deleting nodes with a broken driver

The only reason we need a driver is to stop serial console. Only try
to load the driver in this case.

Change-Id: I5a4e0a40659042087b7a466baae0a8c3dc136211

ironic/conductor/manager.py

@@ -1988,6 +1988,7 @@ class ConductorManager(base_manager.BaseConductorManager):
         # we would disallow it otherwise. That's done for recovering hopelessly
         # broken nodes (e.g. with broken BMC).
         with task_manager.acquire(context, node_id,
+                                  load_driver=False,
                                   purpose='node deletion') as task:
             node = task.node
             if not node.maintenance and node.instance_uuid is not None:
@@ -2022,6 +2023,17 @@ class ConductorManager(base_manager.BaseConductorManager):
             if node.console_enabled:
                 notify_utils.emit_console_notification(
                     task, 'console_set', fields.NotificationStatus.START)
+
+                try:
+                    task.load_driver()
+                except Exception:
+                    with excutils.save_and_reraise_exception():
+                        LOG.exception('Could not load the driver for node %s '
+                                      'to shut down its console', node.uuid)
+                        notify_utils.emit_console_notification(
+                            task, 'console_set',
+                            fields.NotificationStatus.ERROR)
+
                 try:
                     task.driver.console.stop_console(task)
                 except Exception as err:

ironic/conductor/task_manager.py

@@ -253,6 +253,10 @@ class TaskManager(object):
             self.fsm.initialize(start_state=self.node.provision_state,
                                 target_state=self.node.target_provision_state)
 
+    def load_driver(self):
+        if self.driver is None:
+            self.driver = driver_factory.build_driver_for_task(self)
+
     def _lock(self):
         self._debug_timer.restart()
 

ironic/tests/unit/conductor/test_manager.py

@@ -3609,6 +3609,15 @@ class DestroyNodeTestCase(mgr_utils.ServiceSetUpMixin, db_base.DbTestCase):
         self.service.destroy_node(self.context, node.uuid)
         self.assertFalse(mock_power.called)
 
+    def test_destroy_node_broken_driver(self):
+        node = obj_utils.create_test_node(self.context,
+                                          power_interface='broken')
+        self._start_service()
+        self.service.destroy_node(self.context, node.uuid)
+        self.assertRaises(exception.NodeNotFound,
+                          self.dbapi.get_node_by_uuid,
+                          node.uuid)
+
 
 @mgr_utils.mock_record_keepalive
 class CreatePortTestCase(mgr_utils.ServiceSetUpMixin, db_base.DbTestCase):

releasenotes/notes/destroy-broken-8b13de8382199aca.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Allows deleting nodes with a broken driver unless they require stopping
+    serial console.