Deprecate quota_items, register resources upon REST initialization

Register 'core' resources when the respective rest controllers are
instantiated, rather than at module load time.

Since in this way there will not be any need to iterate over
quota_items, the option is being deprecated.

This patch does not supply unit tests as the already-existing
routine for registering a resource from quota_items is being
deprecated as well (and was not covered by any unit test beforehand).

DocImpact

Change-Id: Icdb744adfd86d38363239a454ccf04f3c6b9c158
Closes-Bug: #1453322

etc/neutron.conf

@@ -586,6 +586,7 @@
 # quota_driver = neutron.db.quota_db.DbQuotaDriver
 
 # Resource name(s) that are supported in quota features
+# This option is deprecated for removal in the M release, please refrain from using it
 # quota_items = network,subnet,port
 
 # Default number of resource allowed per tenant. A negative value means

neutron/api/v2/router.py

@@ -26,6 +26,7 @@ from neutron.api.v2 import attributes
 from neutron.api.v2 import base
 from neutron import manager
 from neutron import policy
+from neutron import quota
 from neutron import wsgi
 
 
@@ -104,6 +105,7 @@ class APIRouter(wsgi.Router):
             _map_resource(RESOURCES[resource], resource,
                           attributes.RESOURCE_ATTRIBUTE_MAP.get(
                               RESOURCES[resource], dict()))
+            quota.QUOTAS.register_resource_by_name(resource)
 
         for resource in SUB_RESOURCES:
             _map_resource(SUB_RESOURCES[resource]['collection_name'], resource,

neutron/quota.py

@@ -30,12 +30,15 @@ LOG = logging.getLogger(__name__)
 QUOTA_DB_MODULE = 'neutron.db.quota_db'
 QUOTA_DB_DRIVER = 'neutron.db.quota_db.DbQuotaDriver'
 QUOTA_CONF_DRIVER = 'neutron.quota.ConfDriver'
+default_quota_items = ['network', 'subnet', 'port']
 
 quota_opts = [
     cfg.ListOpt('quota_items',
-                default=['network', 'subnet', 'port'],
+                default=default_quota_items,
+                deprecated_for_removal=True,
                 help=_('Resource name(s) that are supported in quota '
-                       'features')),
+                       'features. This option is now deprecated for '
+                       'removal.')),
     cfg.IntOpt('default_quota',
                default=-1,
                help=_('Default number of resource allowed per tenant. '
@@ -330,8 +333,17 @@ def _count_resource(context, plugin, resources, tenant_id):
 
 
 def register_resources_from_config():
+    # This operation is now deprecated. All the neutron core and extended
+    # resource for which  quota limits are enforced explicitly register
+    # themselves with the quota engine.
+    versionutils.report_deprecated_feature(
+        LOG, _LW("Registering resources to apply quota limits to using the "
+                 "quota_items option is deprecated as of Liberty."
+                 "Resource REST controllers should take care of registering "
+                 "resources with the quota engine."))
     resources = []
-    for resource_item in cfg.CONF.QUOTAS.quota_items:
+    for resource_item in (set(cfg.CONF.QUOTAS.quota_items) -
+                          set(default_quota_items)):
         resources.append(CountableResource(resource_item, _count_resource,
                                            'quota_' + resource_item))
     QUOTAS.register_resources(resources)

neutron/tests/unit/extensions/test_quotasv2.py

@@ -22,6 +22,7 @@ from webob import exc
 import webtest
 
 from neutron.api import extensions
+from neutron.api.v2 import router
 from neutron.common import config
 from neutron.common import constants
 from neutron.common import exceptions
@@ -68,6 +69,9 @@ class QuotaExtensionTestCase(testlib_api.WebTestCase):
         app = config.load_paste_app('extensions_test_app')
         ext_middleware = extensions.ExtensionMiddleware(app, ext_mgr=ext_mgr)
         self.api = webtest.TestApp(ext_middleware)
+        # Initialize the router for the core API in order to ensure core quota
+        # resources are registered
+        router.APIRouter()
 
     def tearDown(self):
         self.api = None