Perform image show early in the resize process

This change addresses bug 943421 by performing glance interactions
much earlier in the resize process. This prevents token expiration
from breaking resizes.

- added a comment to the compute api change to give some context and
  help prevent regression on this bug

Change-Id: I21619f9f6189d5bdec64de47988985cbc3b8016d

3 files changed, 34 insertions, 28 deletions

diff --git a/nova/compute/api.py b/nova/compute/api.py
index d900fb77f..75b8bcf91 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -1310,6 +1310,9 @@ class API(base.Base):
         if not new_instance_type:
             raise exception.FlavorNotFound(flavor_id=flavor_id)
 
+        # NOTE(markwash): look up the image early to avoid auth problems later
+        image = self.image_service.show(context, instance['image_ref'])
+
         current_memory_mb = current_instance_type['memory_mb']
         new_memory_mb = new_instance_type['memory_mb']
 
@@ -1335,8 +1338,9 @@ class API(base.Base):
         args = {
             "topic": FLAGS.compute_topic,
             "instance_uuid": instance['uuid'],
-            "update_db": False,
             "instance_type_id": new_instance_type['id'],
+            "image": image,
+            "update_db": False,
             "request_spec": utils.to_primitive(request_spec),
             "filter_properties": filter_properties,
         }
diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 2221946af..d06786ca0 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -1229,7 +1229,8 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def prep_resize(self, context, instance_uuid, instance_type_id, **kwargs):
+    def prep_resize(self, context, instance_uuid, instance_type_id, image,
+                    **kwargs):
         """Initiates the process of moving a running instance to another host.
 
         Possibly changes the RAM and disk size in the process.
@@ -1269,7 +1270,8 @@ class ComputeManager(manager.SchedulerDependentManager):
         rpc.cast(context, topic,
                 {'method': 'resize_instance',
                  'args': {'instance_uuid': instance_ref['uuid'],
-                          'migration_id': migration_ref['id']}})
+                          'migration_id': migration_ref['id'],
+                          'image': image}})
 
         usage_info = utils.usage_from_instance(instance_ref,
                               new_instance_type=new_instance_type['name'],
@@ -1280,7 +1282,7 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def resize_instance(self, context, instance_uuid, migration_id):
+    def resize_instance(self, context, instance_uuid, migration_id, image):
         """Starts the migration of a running instance to another host."""
         migration_ref = self.db.migration_get(context, migration_id)
         instance_ref = self.db.instance_get_by_uuid(context,
@@ -1314,11 +1316,13 @@ class ComputeManager(manager.SchedulerDependentManager):
                                       migration_ref['dest_compute'])
         params = {'migration_id': migration_id,
                   'disk_info': disk_info,
-                  'instance_uuid': instance_ref['uuid']}
+                  'instance_uuid': instance_ref['uuid'],
+                  'image': image}
         rpc.cast(context, topic, {'method': 'finish_resize',
                                   'args': params})
 
-    def _finish_resize(self, context, instance_ref, migration_ref, disk_info):
+    def _finish_resize(self, context, instance_ref, migration_ref, disk_info,
+                       image):
         resize_instance = False
         old_instance_type_id = migration_ref['old_instance_type_id']
         new_instance_type_id = migration_ref['new_instance_type_id']
@@ -1337,13 +1341,10 @@ class ComputeManager(manager.SchedulerDependentManager):
 
         network_info = self._get_instance_nw_info(context, instance_ref)
 
-        # Have to look up image here since we depend on disk_format later
-        image_meta = _get_image_meta(context, instance_ref['image_ref'])
-
         self.driver.finish_migration(context, migration_ref, instance_ref,
                                      disk_info,
                                      self._legacy_nw_info(network_info),
-                                     image_meta, resize_instance)
+                                     image, resize_instance)
 
         self._instance_update(context,
                               instance_ref.uuid,
@@ -1357,7 +1358,8 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def finish_resize(self, context, instance_uuid, migration_id, disk_info):
+    def finish_resize(self, context, instance_uuid, migration_id, disk_info,
+                      image):
         """Completes the migration process.
 
         Sets up the newly transferred disk and turns on the instance at its
@@ -1371,7 +1373,7 @@ class ComputeManager(manager.SchedulerDependentManager):
 
         try:
             self._finish_resize(context, instance_ref, migration_ref,
-                                disk_info)
+                                disk_info, image)
         except Exception, error:
             with utils.save_and_reraise_exception():
                 msg = _('%s. Setting instance vm_state to ERROR')
diff --git a/nova/tests/test_compute.py b/nova/tests/test_compute.py
index 09e3d8aca..a034e54d0 100644
--- a/nova/tests/test_compute.py
+++ b/nova/tests/test_compute.py
@@ -1033,12 +1033,12 @@ class ComputeTestCase(BaseTestCase):
         context = self.context.elevated()
 
         instance = self._create_fake_instance()
-        self.compute.prep_resize(context, instance['uuid'], 1,
+        self.compute.prep_resize(context, instance['uuid'], 1, {},
                                  filter_properties={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
         self.compute.finish_resize(context, instance['uuid'],
-                                   int(migration_ref['id']), {})
+                                   int(migration_ref['id']), {}, {})
         self.compute.terminate_instance(self.context, instance['uuid'])
 
     def test_finish_resize_handles_error(self):
@@ -1070,14 +1070,14 @@ class ComputeTestCase(BaseTestCase):
                                                           func=fake_nw_info)
         context = self.context.elevated()
         instance = self._create_fake_instance()
-        self.compute.prep_resize(context, instance['uuid'], 1,
+        self.compute.prep_resize(context, instance['uuid'], 1, {},
                                  filter_properties={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
 
         self.assertRaises(Exception, self.compute.finish_resize,
                           context, instance['uuid'],
-                          int(migration_ref['id']), {})
+                          int(migration_ref['id']), {}, {})
 
         instance = db.instance_get_by_uuid(context, instance['uuid'])
         self.assertEqual(instance['vm_state'], vm_states.ERROR)
@@ -1100,7 +1100,7 @@ class ComputeTestCase(BaseTestCase):
         test_notifier.NOTIFICATIONS = []
 
         db.instance_update(self.context, instance_uuid, {'host': 'foo'})
-        self.compute.prep_resize(context, instance_uuid, 1,
+        self.compute.prep_resize(context, instance_uuid, 1, {},
                                  filter_properties={})
         db.migration_get_by_instance_and_status(context,
                                                 instance_uuid,
@@ -1143,7 +1143,7 @@ class ComputeTestCase(BaseTestCase):
         db.instance_update(self.context, instance_uuid, {'host': 'foo'})
 
         self.assertRaises(exception.MigrationError, self.compute.prep_resize,
-                          context, instance_uuid, 1)
+                          context, instance_uuid, 1, {})
         self.compute.terminate_instance(context, instance_uuid)
 
     def test_resize_instance_driver_error(self):
@@ -1161,14 +1161,14 @@ class ComputeTestCase(BaseTestCase):
 
         self.compute.run_instance(self.context, instance_uuid)
         db.instance_update(self.context, instance_uuid, {'host': 'foo'})
-        self.compute.prep_resize(context, instance_uuid, 1,
+        self.compute.prep_resize(context, instance_uuid, 1, {},
                                  filter_properties={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance_uuid, 'pre-migrating')
 
         #verify
         self.assertRaises(Exception, self.compute.resize_instance, context,
-                          instance_uuid, migration_ref['id'])
+                          instance_uuid, migration_ref['id'], {})
         instance = db.instance_get_by_uuid(context, instance_uuid)
         self.assertEqual(instance['vm_state'], vm_states.ERROR)
 
@@ -1183,12 +1183,12 @@ class ComputeTestCase(BaseTestCase):
         self.compute.run_instance(self.context, instance_uuid)
         db.instance_update(self.context, instance_uuid,
                            {'host': 'foo'})
-        self.compute.prep_resize(context, instance_uuid, 1,
+        self.compute.prep_resize(context, instance_uuid, 1, {},
                                  filter_properties={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance_uuid, 'pre-migrating')
         self.compute.resize_instance(context, instance_uuid,
-                migration_ref['id'])
+                migration_ref['id'], {})
         self.compute.terminate_instance(context, instance_uuid)
 
     def test_finish_revert_resize(self):
@@ -1235,16 +1235,16 @@ class ComputeTestCase(BaseTestCase):
 
         new_instance_type_ref = db.instance_type_get_by_flavor_id(context, 3)
         self.compute.prep_resize(context, inst_ref['uuid'],
-                                 new_instance_type_ref['id'],
+                                 new_instance_type_ref['id'], {},
                                  filter_properties={})
 
         migration_ref = db.migration_get_by_instance_and_status(context,
                 inst_ref['uuid'], 'pre-migrating')
 
         self.compute.resize_instance(context, inst_ref['uuid'],
-                migration_ref['id'])
+                migration_ref['id'], {})
         self.compute.finish_resize(context, inst_ref['uuid'],
-                    int(migration_ref['id']), {})
+                    int(migration_ref['id']), {}, {})
 
         # Prove that the instance size is now the new size
         inst_ref = db.instance_get_by_uuid(context, instance_uuid)
@@ -1281,7 +1281,7 @@ class ComputeTestCase(BaseTestCase):
         self.compute.run_instance(self.context, instance['uuid'])
         instance = db.instance_get_by_uuid(self.context, instance['uuid'])
         self.assertRaises(exception.MigrationError, self.compute.prep_resize,
-                self.context, instance['uuid'], 1)
+                self.context, instance['uuid'], 1, {})
         self.compute.terminate_instance(self.context, instance['uuid'])
 
     def test_resize_instance_handles_migration_error(self):
@@ -1297,12 +1297,12 @@ class ComputeTestCase(BaseTestCase):
 
         self.compute.run_instance(self.context, inst_ref['uuid'])
         db.instance_update(self.context, inst_ref['uuid'], {'host': 'foo'})
-        self.compute.prep_resize(context, inst_ref['uuid'], 1,
+        self.compute.prep_resize(context, inst_ref['uuid'], 1, {},
                                  filter_properties={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 inst_ref['uuid'], 'pre-migrating')
         self.assertRaises(Exception, self.compute.resize_instance,
-                          context, inst_ref['uuid'], migration_ref['id'])
+                          context, inst_ref['uuid'], migration_ref['id'], {})
         inst_ref = db.instance_get_by_uuid(context, inst_ref['uuid'])
         self.assertEqual(inst_ref['vm_state'], vm_states.ERROR)
         self.compute.terminate_instance(context, inst_ref['uuid'])