Fix a lazy-load exception in security_group_update()

When security_group_api is nova, the update_security_group api raises http
500 error: group rules fails with lazy load exception. Because the rule
infos of the security group will be return in response body, but the rule
attribute hasn't been preloaded.

Closes-Bug: #1244018
Change-Id: Ie07879ac22e4add90f75968778bf334915e8349c

nova/compute/api.py

@@ -3451,9 +3451,11 @@ class SecurityGroupAPI(base.Base, security_group_base.SecurityGroupBase):
         group = {'name': name,
                  'description': description}
 
+        columns_to_join = ['rules.grantee_group']
         group_ref = self.db.security_group_update(context,
-                                                  security_group['id'],
-                                                  group)
+                security_group['id'],
+                group,
+                columns_to_join=columns_to_join)
         return group_ref
 
     def get(self, context, name=None, id=None, map_exception=False):

nova/db/api.py

@@ -1248,9 +1248,11 @@ def security_group_create(context, values):
     return IMPL.security_group_create(context, values)
 
 
-def security_group_update(context, security_group_id, values):
+def security_group_update(context, security_group_id, values,
+                          columns_to_join=None):
     """Update a security group."""
-    return IMPL.security_group_update(context, security_group_id, values)
+    return IMPL.security_group_update(context, security_group_id, values,
+                                      columns_to_join=columns_to_join)
 
 
 def security_group_ensure_default(context):

nova/db/sqlalchemy/api.py

@@ -3719,13 +3719,16 @@ def security_group_create(context, values):
 
 
 @require_context
-def security_group_update(context, security_group_id, values):
+def security_group_update(context, security_group_id, values,
+                          columns_to_join=None):
     session = get_session()
     with session.begin():
-        security_group_ref = model_query(context, models.SecurityGroup,
-                                         session=session).\
-                                filter_by(id=security_group_id).\
-                                first()
+        query = model_query(context, models.SecurityGroup,
+                         session=session).filter_by(id=security_group_id)
+        if columns_to_join:
+            for column in columns_to_join:
+                query = query.options(joinedload_all(column))
+        security_group_ref = query.first()
 
         if not security_group_ref:
             raise exception.SecurityGroupNotFound(

nova/tests/api/openstack/compute/contrib/test_security_groups.py

@@ -426,7 +426,8 @@ class TestSecurityGroups(test.TestCase):
             self.assertEqual(sg['id'], group_id)
             return security_group_db(sg)
 
-        def return_update_security_group(context, group_id, values):
+        def return_update_security_group(context, group_id, values,
+                                         columns_to_join=None):
             self.assertEqual(sg_update['id'], group_id)
             self.assertEqual(sg_update['name'], values['name'])
             self.assertEqual(sg_update['description'], values['description'])

nova/tests/db/test_db_api.py

@@ -1297,11 +1297,15 @@ class SecurityGroupTestCase(test.TestCase, ModelsObjectComparatorMixin):
                     'user_id': 'fake_user1',
                     'project_id': 'fake_proj1',
         }
+
+        columns_to_join = ['rules.grantee_group']
         updated_group = db.security_group_update(self.ctxt,
-                                                 security_group['id'],
-                                                 new_values)
+                                    security_group['id'],
+                                    new_values,
+                                    columns_to_join=['rules.grantee_group'])
         for key, value in new_values.iteritems():
             self.assertEqual(updated_group[key], value)
+        self.assertEqual(updated_group['rules'], [])
 
     def test_security_group_update_to_duplicate(self):
         security_group1 = self._create_security_group(