From a84be486c80da690b627d99644a5ed656757097c Mon Sep 17 00:00:00 2001
From: Takashi NATSUME <natsume.takashi@lab.ntt.co.jp>
Date: Fri, 13 Feb 2015 14:33:11 +0900
Subject: [PATCH] Handle MessagingException in unshelving instance

Add Handling MessagingException in nova-conductor
when unshelving instance

Change-Id: I4dd95ee08e9618b8fd51f043c0f89f4ddcf1cb35
Closes-Bug: #1367186
---
 nova/conductor/manager.py                   |  6 +++++
 nova/tests/unit/conductor/test_conductor.py | 25 +++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/nova/conductor/manager.py b/nova/conductor/manager.py
index 213c269b8932..25bf082cbe83 100644
--- a/nova/conductor/manager.py
+++ b/nova/conductor/manager.py
@@ -766,6 +766,12 @@ class ComputeTaskManager(base.Base):
                 LOG.warning(_LW("No valid host found for unshelve instance"),
                             instance=instance)
                 return
+            except Exception:
+                with excutils.save_and_reraise_exception():
+                    instance.task_state = None
+                    instance.save()
+                    LOG.error(_LE("Unshelve attempted but an error "
+                                  "has occurred"), instance=instance)
         else:
             LOG.error(_LE('Unshelve attempted but vm_state not SHELVED or '
                           'SHELVED_OFFLOADED'), instance=instance)
diff --git a/nova/tests/unit/conductor/test_conductor.py b/nova/tests/unit/conductor/test_conductor.py
index 63fe9cf62821..f722817124e6 100644
--- a/nova/tests/unit/conductor/test_conductor.py
+++ b/nova/tests/unit/conductor/test_conductor.py
@@ -40,6 +40,7 @@ from nova import context
 from nova import db
 from nova.db.sqlalchemy import models
 from nova import exception as exc
+from nova.image import api as image_api
 from nova import notifications
 from nova import objects
 from nova.objects import base as obj_base
@@ -1545,6 +1546,30 @@ class _BaseTaskTestCase(object):
                                       show_deleted=False)])
             self.assertEqual(vm_states.SHELVED_OFFLOADED, instance.vm_state)
 
+    @mock.patch.object(conductor_manager.ComputeTaskManager,
+                       '_schedule_instances',
+                       side_effect=messaging.MessagingTimeout())
+    @mock.patch.object(image_api.API, 'get', return_value='fake_image')
+    def test_unshelve_instance_schedule_and_rebuild_messaging_exception(
+            self, mock_get_image, mock_schedule_instances):
+        instance = self._create_fake_instance_obj()
+        instance.vm_state = vm_states.SHELVED_OFFLOADED
+        instance.task_state = task_states.UNSHELVING
+        instance.save()
+        system_metadata = instance.system_metadata
+
+        system_metadata['shelved_at'] = timeutils.utcnow()
+        system_metadata['shelved_image_id'] = 'fake_image_id'
+        system_metadata['shelved_host'] = 'fake-mini'
+        self.assertRaises(messaging.MessagingTimeout,
+                          self.conductor_manager.unshelve_instance,
+                          self.context, instance)
+        mock_get_image.assert_has_calls([mock.call(self.context,
+                                        system_metadata['shelved_image_id'],
+                                        show_deleted=False)])
+        self.assertEqual(vm_states.SHELVED_OFFLOADED, instance.vm_state)
+        self.assertIsNone(instance.task_state)
+
     def test_unshelve_instance_schedule_and_rebuild_volume_backed(self):
         instance = self._create_fake_instance_obj()
         instance.vm_state = vm_states.SHELVED_OFFLOADED