Moved CORS middleware configuration into oslo-config-generator

The default values needed for ceilometer's implementation of cors
middleware have been moved from paste.ini into the configuration
hooks provided by oslo.config. Furthermore, these values have been
added to ceilometer's default configuration parsing. This ensures
that if a value remains unset in ceilometer.conf, it will be set
to use sane defaults, and that an operator modifying the
configuration file will be presented with a default set of
necessary sane headers.

Closes-Bug: 1551836
Change-Id: Iaab90bfa1811bf6d56696648a000f02ee3306285

ceilometer/conf/defaults.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_cors_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-Identity-Status',
+                                    'X-Roles',
+                                    'X-Service-Catalog',
+                                    'X-User-Id',
+                                    'X-Tenant-Id',
+                                    'X-Openstack-Request-Id'],
+                     expose_headers=['X-Auth-Token',
+                                     'X-Subject-Token',
+                                     'X-Service-Token',
+                                     'X-Openstack-Request-Id'],
+                     allow_methods=['GET',
+                                    'PUT',
+                                    'POST',
+                                    'DELETE',
+                                    'PATCH']
+                     )

ceilometer/service.py

@@ -22,6 +22,7 @@ import oslo_i18n
 from oslo_log import log
 from oslo_reports import guru_meditation_report as gmr
 
+from ceilometer.conf import defaults
 from ceilometer import keystone_client
 from ceilometer import messaging
 from ceilometer import version
@@ -75,6 +76,7 @@ def prepare_service(argv=None, config_files=None):
                   ['stevedore=INFO', 'keystoneclient=INFO',
                    'neutronclient=INFO'])
     log.set_defaults(default_log_levels=log_levels)
+    defaults.set_cors_middleware_defaults()
 
     if argv is None:
         argv = sys.argv

ceilometer/tests/functional/gabbi/gabbi_paste.ini

@@ -22,6 +22,3 @@ paste.filter_factory = oslo_middleware:RequestId.factory
 [filter:cors]
 paste.filter_factory = oslo_middleware.cors:filter_factory
 oslo_config_project = ceilometer
-latent_allow_headers = X-Auth-Token, X-Identity-Status, X-Roles, X-Service-Catalog, X-User-Id, X-Tenant-Id, X-OpenStack-Request-ID
-latent_expose_headers = X-Auth-Token, X-Subject-Token, X-Service-Token, X-OpenStack-Request-ID
-latent_allow_methods = GET, PUT, POST, DELETE, PATCH

etc/ceilometer/api_paste.ini

@@ -19,6 +19,3 @@ paste.filter_factory = oslo_middleware:RequestId.factory
 [filter:cors]
 paste.filter_factory = oslo_middleware.cors:filter_factory
 oslo_config_project = ceilometer
-latent_allow_headers = X-Auth-Token, X-Identity-Status, X-Roles, X-Service-Catalog, X-User-Id, X-Tenant-Id, X-OpenStack-Request-ID
-latent_expose_headers = X-Auth-Token, X-Subject-Token, X-Service-Token, X-OpenStack-Request-ID
-latent_allow_methods = GET, PUT, POST, DELETE, PATCH

setup.cfg

@@ -266,6 +266,9 @@ network.statistics.drivers =
 oslo.config.opts =
     ceilometer = ceilometer.opts:list_opts
 
+oslo.config.opts.defaults =
+    oslo.middleware.cors = ceilometer.conf.defaults:set_cors_middleware_defaults
+
 keystoneauth1.plugin =
     password-ceilometer-legacy = ceilometer.keystone_client:LegacyCeilometerKeystoneLoader