Config options: centralize cache options

The config options of the "nova.conf" section "cache" got
moved to the new central location "nova/conf/cache.py".

Change-Id: I1b7aebb9f7d44ff8312b98c88093bf01f44dfa58
Implements: blueprint centralize-config-options-newton

etc/nova/nova-config-generator.conf

@@ -7,7 +7,6 @@ namespace = nova.api
 namespace = nova.cells
 namespace = nova.compute
 namespace = nova.network
-namespace = oslo.cache
 namespace = oslo.log
 namespace = oslo.messaging
 namespace = oslo.policy

nova/cache_utils.py

@@ -17,12 +17,12 @@
 """Super simple fake memcache client."""
 
 from oslo_cache import core as cache
-from oslo_config import cfg
 
+import nova.conf
 from nova.i18n import _
 
 
-CONF = cfg.CONF
+CONF = nova.conf.CONF
 
 WEEK = 604800
 

nova/conf/__init__.py

@@ -25,6 +25,7 @@ from nova.conf import availability_zone
 # from nova.conf import aws
 from nova.conf import barbican
 from nova.conf import base
+from nova.conf import cache
 from nova.conf import cells
 from nova.conf import cert
 from nova.conf import cinder
@@ -97,6 +98,7 @@ availability_zone.register_opts(CONF)
 # aws.register_opts(CONF)
 barbican.register_opts(CONF)
 base.register_opts(CONF)
+cache.register_opts(CONF)
 cells.register_opts(CONF)
 cert.register_opts(CONF)
 cinder.register_opts(CONF)

nova/conf/cache.py

@@ -0,0 +1,26 @@
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# Copyright 2016 OpenStack Foundation
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from oslo_cache import core
+
+
+def register_opts(conf):
+    core.configure(conf)
+
+
+def list_opts():
+    return core._opts.list_opts()

nova/config.py

@@ -15,7 +15,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslo_cache import core as cache
 from oslo_db import options
 from oslo_log import log
 
@@ -44,7 +43,6 @@ def parse_args(argv, default_config_files=None, configure_db=True,
     options.set_defaults(CONF, connection=_DEFAULT_SQL_CONNECTION,
                          sqlite_db='nova.sqlite')
     rpc.set_defaults(control_exchange='nova')
-    cache.configure(CONF)
     config.set_middleware_defaults()
 
     CONF(argv[1:],