Moved CORS middleware configuration into oslo-config-generator

The default values needed for congress'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 the default initialization procedure. This ensures
that if a value remains unset in the configuration file, it will
fallback to using sane defaults. It also ensures that an operator
modifying the configuration will be presented with that same
set of defaults.

Change-Id: I2edc24e4d47c4d664dd31c407d46e42fefdb1488
Closes-Bug: #1551836

congress/auth.py

@@ -22,6 +22,7 @@ from oslo_middleware import request_id
 import webob.dec
 import webob.exc
 
+from congress.common import config
 from congress.common import wsgi
 from congress import context
 
@@ -67,6 +68,7 @@ class CongressKeystoneContext(wsgi.Middleware):
 
 def pipeline_factory(loader, global_conf, **local_conf):
     """Create a paste pipeline based on the 'auth_strategy' config option."""
+    config.set_config_defaults()
     pipeline = local_conf[cfg.CONF.auth_strategy]
     pipeline = pipeline.split()
     filters = [loader.get_filter(n) for n in pipeline[:-1]]

congress/common/config.py

@@ -21,6 +21,7 @@ import os
 from oslo_config import cfg
 from oslo_db import options as db_options
 from oslo_log import log as logging
+from oslo_middleware import cors
 from oslo_policy import opts as policy_opts
 
 from congress.managers import datasource as datasource_mgr
@@ -106,3 +107,27 @@ def find_paste_config():
     config_path = os.path.abspath(config_path)
     LOG.info(_("Config paste file: %s"), config_path)
     return config_path
+
+
+def set_config_defaults():
+    """This method updates all configuration default values."""
+    # 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']
+                     )

congress/server/congress_server.py

@@ -94,6 +94,7 @@ def main():
     #   event loop -> wsgi server -> webapp -> resource manager
 
     paste_config = config.find_paste_config()
+    config.set_config_defaults()
     servers = []
     servers.append(create_api_server(paste_config,
                                      "congress",

etc/api-paste.ini

@@ -32,6 +32,3 @@ paste.filter_factory = keystonemiddleware.auth_token:filter_factory
 [filter:cors]
 paste.filter_factory =  oslo_middleware.cors:filter_factory
 oslo_config_project = congress
-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

@@ -32,6 +32,9 @@ setup-hooks =
 oslo.config.opts =
     congress = congress.opts:list_opts
 
+oslo.config.opts.defaults =
+    congress = congress.common.config:set_config_defaults
+
 console_scripts =
     congress-server = congress.server.congress_server:main
     congress-db-manage = congress.db.migration.cli:main