Editable default quota support

Implement blueprint edit-default-quota

DocImpact

Using the class quotas named `default` as the default editable quotas.

We can use the following novaclient command to update default quota:

nova quota-class-update default <key> <value>

Change-Id: I5a5001fadcbd61d550ebd5bdc33613b0ffdf29b2

nova/quota.py

@@ -105,14 +105,18 @@ class DbQuotaDriver(object):
 
     def get_defaults(self, context, resources):
         """Given a list of resources, retrieve the default quotas.
+        Use the class quotas named `_DEFAULT_QUOTA_NAME` as default quotas,
+        if it exists.
 
         :param context: The request context, for access checks.
         :param resources: A dictionary of the registered resources.
         """
 
         quotas = {}
+        default_quotas = db.quota_class_get_default(context)
         for resource in resources.values():
-            quotas[resource.name] = resource.default
+            quotas[resource.name] = default_quotas.get(resource.name,
+                                                       resource.default)
 
         return quotas
 
@@ -180,6 +184,8 @@ class DbQuotaDriver(object):
         else:
             class_quotas = {}
 
+        default_quotas = self.get_defaults(context, resources)
+
         for resource in resources.values():
             # Omit default/quota class values
             if not defaults and resource.name not in project_quotas:
@@ -187,7 +193,7 @@ class DbQuotaDriver(object):
 
             quotas[resource.name] = dict(
                 limit=project_quotas.get(resource.name, class_quotas.get(
-                        resource.name, resource.default)),
+                        resource.name, default_quotas[resource.name])),
                 )
 
             # Include usages if desired.  This is optional because one

nova/tests/test_db_api.py

@@ -3930,6 +3930,28 @@ class KeyPairTestCase(test.TestCase, ModelsObjectComparatorMixin):
                           param['user_id'], param['name'])
 
 
+class QuotaClassTestCase(test.TestCase, ModelsObjectComparatorMixin):
+
+    def setUp(self):
+        super(QuotaClassTestCase, self).setUp()
+        self.ctxt = context.get_admin_context()
+
+    def test_quota_class_get_default(self):
+        params = {
+            'test_resource1': '10',
+            'test_resource2': '20',
+            'test_resource3': '30',
+        }
+        for res, limit in params.items():
+            db.quota_class_create(self.ctxt, 'default', res, limit)
+
+        defaults = db.quota_class_get_default(self.ctxt)
+        self.assertEqual(defaults, dict(class_name='default',
+                                        test_resource1=10,
+                                        test_resource2=20,
+                                        test_resource3=30))
+
+
 class ArchiveTestCase(test.TestCase):
 
     def setUp(self):