Fallback to conductor if types are not stashed.

If the instance types are not stashed, fallback to
the conductor API to retrieve them.

bug 1164110

Change-Id: I1f0ef48e072f8580980de5bd8d43cf2206cd7d27
(cherry picked from commit e9c88b7)

nova/compute/resource_tracker.py

@@ -145,8 +145,8 @@ def resize_claim(self, context, instance_ref, instance_type, limits=None):
 
             # Mark the resources in-use for the resize landing on this
             # compute host:
-            self._update_usage_from_migration(instance_ref, self.compute_node,
-                                              migration_ref)
+            self._update_usage_from_migration(context, instance_ref,
+                                              self.compute_node, migration_ref)
             elevated = context.elevated()
             self._update(elevated, self.compute_node)
 
@@ -263,7 +263,7 @@ def update_available_resource(self, context, delete=False):
         migrations = capi.migration_get_in_progress_by_host_and_node(context,
                 self.host, self.nodename)
 
-        self._update_usage_from_migrations(resources, migrations)
+        self._update_usage_from_migrations(context, resources, migrations)
 
         # Detect and account for orphaned instances that may exist on the
         # hypervisor, but are not in the DB:
@@ -387,7 +387,8 @@ def _update_usage(self, resources, usage, sign=1):
         resources['running_vms'] = self.stats.num_instances
         resources['vcpus_used'] = self.stats.num_vcpus_used
 
-    def _update_usage_from_migration(self, instance, resources, migration):
+    def _update_usage_from_migration(self, context, instance, resources,
+                                     migration):
         """Update usage for a single migration.  The record may
         represent an incoming or outbound migration.
         """
@@ -408,27 +409,31 @@ def _update_usage_from_migration(self, instance, resources, migration):
             # instance is *not* in:
             if (instance['instance_type_id'] ==
                 migration['old_instance_type_id']):
-                itype = instance_types.extract_instance_type(instance)
+                itype = self._get_instance_type(context, instance, 'new_',
+                        migration['new_instance_type_id'])
             else:
                 # instance record already has new flavor, hold space for a
                 # possible revert to the old instance type:
-                itype = instance_types.extract_instance_type(instance, 'old_')
+                itype = self._get_instance_type(context, instance, 'old_',
+                        migration['old_instance_type_id'])
 
         elif incoming and not record:
             # instance has not yet migrated here:
-            itype = instance_types.extract_instance_type(instance, 'new_')
+            itype = self._get_instance_type(context, instance, 'new_',
+                    migration['new_instance_type_id'])
 
         elif outbound and not record:
             # instance migrated, but record usage for a possible revert:
-            itype = instance_types.extract_instance_type(instance, 'old_')
+            itype = self._get_instance_type(context, instance, 'old_',
+                    migration['old_instance_type_id'])
 
         if itype:
             self.stats.update_stats_for_migration(itype)
             self._update_usage(resources, itype)
             resources['stats'] = self.stats
             self.tracked_migrations[uuid] = (migration, itype)
 
-    def _update_usage_from_migrations(self, resources, migrations):
+    def _update_usage_from_migrations(self, context, resources, migrations):
 
         self.tracked_migrations.clear()
 
@@ -459,7 +464,7 @@ def _update_usage_from_migrations(self, resources, migrations):
 
         for migration in filtered.values():
             try:
-                self._update_usage_from_migration(instance, resources,
+                self._update_usage_from_migration(context, instance, resources,
                                                   migration)
             except exception.InstanceTypeNotFound:
                 LOG.warn(_("InstanceType could not be found, skipping "
@@ -575,3 +580,19 @@ def _instance_in_resize_state(self, instance):
             return True
 
         return False
+
+    def _get_instance_type(self, context, instance, prefix,
+            instance_type_id=None):
+        """Get the instance type from sys metadata if it's stashed.  If not,
+        fall back to fetching it via the conductor API.
+
+        See bug 1164110
+        """
+        if not instance_type_id:
+            instance_type_id = instance['instance_type_id']
+
+        try:
+            return instance_types.extract_instance_type(instance, prefix)
+        except KeyError:
+            return self.conductor_api.instance_type_get(context,
+                    instance_type_id)

nova/tests/compute/test_resource_tracker.py

@@ -161,14 +161,18 @@ def _fake_instance_system_metadata(self, instance_type, prefix=''):
                              'value': instance_type[key]})
         return sys_meta
 
-    def _fake_instance(self, *args, **kwargs):
+    def _fake_instance(self, stash=True, **kwargs):
 
         # Default to an instance ready to resize to or from the same
         # instance_type
         itype = self._fake_instance_type_create()
-        sys_meta = (self._fake_instance_system_metadata(itype) +
-                    self._fake_instance_system_metadata(itype, 'new_') +
-                    self._fake_instance_system_metadata(itype, 'old_'))
+        sys_meta = self._fake_instance_system_metadata(itype)
+
+        if stash:
+            # stash instance types in system metadata.
+            sys_meta = (sys_meta +
+                        self._fake_instance_system_metadata(itype, 'new_') +
+                        self._fake_instance_system_metadata(itype, 'old_'))
 
         instance_uuid = str(uuid.uuid1())
         instance = {
@@ -876,6 +880,20 @@ def test_set_instance_host_and_node(self):
         self.assertEqual('fakenode', instance['node'])
 
 
+class NoInstanceTypesInSysMetadata(ResizeClaimTestCase):
+    """Make sure we handle the case where the following are true:
+    1) Compute node C gets upgraded to code that looks for instance types in
+       system metadata. AND
+    2) C already has instances in the process of migrating that do not have
+       stashed instance types.
+
+    bug 1164110
+    """
+    def setUp(self):
+        super(NoInstanceTypesInSysMetadata, self).setUp()
+        self.instance = self._fake_instance(stash=False)
+
+
 class OrphanTestCase(BaseTrackerTestCase):
     def _driver(self):
         class OrphanVirtDriver(FakeVirtDriver):