Fix use of potentially-stale instance_type in tenant_usage

The simple_tenant_usage API extension may return incorrect billing
information if a flavor is changed or deleted while an instance using
it is still running. This makes it use the stashed instance_type instead.

Fixes bug 1154707

Change-Id: Ifce33488e5ef8aa942051d882407a3e2d088aaf5

2 files changed, 18 insertions, 24 deletions

diff --git a/nova/api/openstack/compute/contrib/simple_tenant_usage.py b/nova/api/openstack/compute/contrib/simple_tenant_usage.py
index f759e90b0..0fa9b9e40 100644
--- a/nova/api/openstack/compute/contrib/simple_tenant_usage.py
+++ b/nova/api/openstack/compute/contrib/simple_tenant_usage.py
@@ -24,7 +24,7 @@ from nova.api.openstack import extensions
 from nova.api.openstack import wsgi
 from nova.api.openstack import xmlutil
 from nova.compute import api
-from nova import exception
+from nova.compute import instance_types
 from nova.openstack.common import timeutils
 
 authorize_show = extensions.extension_authorizer('compute',
@@ -119,18 +119,7 @@ class SimpleTenantUsageController(object):
             info['hours'] = self._hours_for(instance,
                                             period_start,
                                             period_stop)
-            flavor_type = instance['instance_type_id']
-
-            if not flavors.get(flavor_type):
-                try:
-                    it_ref = compute_api.get_instance_type(context,
-                                                           flavor_type)
-                    flavors[flavor_type] = it_ref
-                except exception.InstanceTypeNotFound:
-                    # can't bill if there is no instance type
-                    continue
-
-            flavor = flavors[flavor_type]
+            flavor = instance_types.extract_instance_type(instance)
 
             info['instance_id'] = instance['uuid']
             info['name'] = instance['display_name']
diff --git a/nova/tests/api/openstack/compute/contrib/test_simple_tenant_usage.py b/nova/tests/api/openstack/compute/contrib/test_simple_tenant_usage.py
index 4c59e5aa9..ab9906135 100644
--- a/nova/tests/api/openstack/compute/contrib/test_simple_tenant_usage.py
+++ b/nova/tests/api/openstack/compute/contrib/test_simple_tenant_usage.py
@@ -22,6 +22,7 @@ import webob
 
 from nova.api.openstack.compute.contrib import simple_tenant_usage
 from nova.compute import api
+from nova.compute import instance_types
 from nova import context
 from nova.openstack.common import jsonutils
 from nova.openstack.common import policy as common_policy
@@ -29,6 +30,7 @@ from nova.openstack.common import timeutils
 from nova import policy
 from nova import test
 from nova.tests.api.openstack import fakes
+from nova import utils
 
 SERVERS = 5
 TENANTS = 2
@@ -42,17 +44,21 @@ START = NOW - datetime.timedelta(hours=HOURS)
 STOP = NOW
 
 
-def fake_instance_type_get(self, context, instance_type_id):
-    return {'id': 1,
-            'vcpus': VCPUS,
-            'root_gb': ROOT_GB,
-            'ephemeral_gb': EPHEMERAL_GB,
-            'memory_mb': MEMORY_MB,
-            'name':
-            'fakeflavor'}
+FAKE_INST_TYPE = {'id': 1,
+                  'vcpus': VCPUS,
+                  'root_gb': ROOT_GB,
+                  'ephemeral_gb': EPHEMERAL_GB,
+                  'memory_mb': MEMORY_MB,
+                  'name': 'fakeflavor',
+                  'flavorid': 'foo',
+                  'rxtx_factor': 1.0,
+                  'vcpu_weight': 1,
+                  'swap': 0}
 
 
 def get_fake_db_instance(start, end, instance_id, tenant_id):
+    sys_meta = utils.dict_to_metadata(
+        instance_types.save_instance_type_info({}, FAKE_INST_TYPE))
     return {'id': instance_id,
             'uuid': '00000000-0000-0000-0000-00000000000000%02d' % instance_id,
             'image_ref': '1',
@@ -62,7 +68,8 @@ def get_fake_db_instance(start, end, instance_id, tenant_id):
             'state_description': 'state',
             'instance_type_id': 1,
             'launched_at': start,
-            'terminated_at': end}
+            'terminated_at': end,
+            'system_metadata': sys_meta}
 
 
 def fake_instance_get_active_by_window_joined(self, context, begin, end,
@@ -77,8 +84,6 @@ def fake_instance_get_active_by_window_joined(self, context, begin, end,
 class SimpleTenantUsageTest(test.TestCase):
     def setUp(self):
         super(SimpleTenantUsageTest, self).setUp()
-        self.stubs.Set(api.API, "get_instance_type",
-                       fake_instance_type_get)
         self.stubs.Set(api.API, "get_active_by_window",
                        fake_instance_get_active_by_window_joined)
         self.admin_context = context.RequestContext('fakeadmin_0',