Added Keystone and RequestID headers to CORS middleware

This patch makes use of oslo.config's genconfig hooks to add
nova-specific default config values to the generated configuration.
It also adds this same method to nova's configuration parsing logic,
to ensure that these default values are also the ones used at runtime.

Closes-bug: 1551836
Change-Id: Ic799aea89f681ef8626e996f0357ade388f76ca9

nova/common/config.py

@@ -0,0 +1,40 @@
+# Copyright 2016 Hewlett Packard Enterprise Development Company, L.P.
+#
+# 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_config import cfg
+from oslo_middleware import cors
+
+
+def set_middleware_defaults():
+    """Update default configuration options for oslo.middleware."""
+    # CORS Defaults
+    # TODO(krotscheck): Update with https://review.openstack.org/#/c/285368/
+    cfg.set_defaults(cors.CORS_OPTS,
+                     allow_headers=['X-Auth-Token',
+                                    'X-Openstack-Request-Id',
+                                    'X-Identity-Status',
+                                    'X-Roles',
+                                    'X-Service-Catalog',
+                                    'X-User-Id',
+                                    'X-Tenant-Id'],
+                     expose_headers=['X-Auth-Token',
+                                     'X-Openstack-Request-Id',
+                                     'X-Subject-Token',
+                                     'X-Service-Token'],
+                     allow_methods=['GET',
+                                    'PUT',
+                                    'POST',
+                                    'DELETE',
+                                    'PATCH']
+                     )

nova/config.py

@@ -20,13 +20,13 @@ from oslo_config import cfg
 from oslo_db import options
 from oslo_log import log
 
+from nova.common import config
 from nova.db.sqlalchemy import api as sqlalchemy_api
 from nova import debugger
 from nova import paths
 from nova import rpc
 from nova import version
 
-
 CONF = cfg.CONF
 
 _DEFAULT_SQL_CONNECTION = 'sqlite:///' + paths.state_path_def('nova.sqlite')
@@ -57,6 +57,8 @@ def parse_args(argv, default_config_files=None, configure_db=True,
     rpc.set_defaults(control_exchange='nova')
     cache.configure(CONF)
     debugger.register_cli_opts()
+    config.set_middleware_defaults()
+
     CONF(argv[1:],
          project='nova',
          version=version.version_string(),

setup.cfg

@@ -36,6 +36,9 @@ oslo.config.opts =
     nova.virt = nova.virt.opts:list_opts
     nova.cache_utils = nova.cache_utils:list_opts
 
+oslo.config.opts.defaults =
+    oslo.middleware = nova.common.config:set_middleware_defaults
+
 nova.compute.monitors.cpu =
     virt_driver = nova.compute.monitors.cpu.virt_driver:Monitor
 nova.compute.resources =