Moved CORS middleware configuration into oslo-config-generator

The default values needed for glance'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 glance's default configuration parsing. This ensures
that if a value remains unset in glance-api.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.

Change-Id: I3c9d267b6224d6c7e5cc2c41cb51fb7e363c4955
Closes-Bug: 1551836

etc/glance-api-paste.ini

@@ -85,20 +85,3 @@ enabled = yes  #DEPRECATED
 paste.filter_factory =  oslo_middleware.cors:filter_factory
 oslo_config_project = glance
 oslo_config_program = glance-api
-# Basic Headers (Automatic)
-# Accept = Origin, Accept, Accept-Language, Content-Type, Cache-Control, Content-Language, Expires, Last-Modified, Pragma
-# Expose = Origin, Accept, Accept-Language, Content-Type, Cache-Control, Content-Language, Expires, Last-Modified, Pragma
-
-# Glance Headers
-# Accept = Content-MD5, X-Image-Meta-Checksum, X-Storage-Token, Accept-Encoding
-# Expose = X-Image-Meta-Checksum
-
-# Keystone Headers
-# Accept = X-Auth-Token, X-Identity-Status, X-Roles, X-Service-Catalog, X-User-Id, X-Tenant-Id
-# Expose = X-Auth-Token, X-Subject-Token, X-Service-Token
-
-# Request ID Middleware Headers
-# Accept = X-OpenStack-Request-ID
-# Expose = X-OpenStack-Request-ID
-latent_allow_headers = Content-MD5, X-Image-Meta-Checksum, X-Storage-Token, Accept-Encoding, 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-Image-Meta-Checksum, X-Auth-Token, X-Subject-Token, X-Service-Token, X-OpenStack-Request-ID

glance/cmd/api.py

@@ -71,6 +71,7 @@ def fail(e):
 def main():
     try:
         config.parse_args()
+        config.set_config_defaults()
         wsgi.set_eventlet_hub()
         logging.setup(CONF, 'glance')
         notifier.set_defaults()

glance/cmd/manage.py

@@ -323,6 +323,7 @@ def main():
         cfg_files.extend(cfg.find_config_files(project='glance',
                                                prog='glance-manage'))
         config.parse_args(default_config_files=cfg_files)
+        config.set_config_defaults()
         logging.setup(CONF, 'glance')
     except RuntimeError as e:
         sys.exit("ERROR: %s" % e)

glance/cmd/registry.py

@@ -56,6 +56,7 @@ logging.register_options(CONF)
 def main():
     try:
         config.parse_args()
+        config.set_config_defaults()
         wsgi.set_eventlet_hub()
         logging.setup(CONF, 'glance')
         notifier.set_defaults()

glance/common/config.py

@@ -23,6 +23,7 @@ import logging.handlers
 import os
 
 from oslo_config import cfg
+from oslo_middleware import cors
 from oslo_policy import policy
 from paste import deploy
 
@@ -273,3 +274,37 @@ def load_paste_app(app_name, flavor=None, conf_file=None):
                                     'e': e})
         logger.error(msg)
         raise RuntimeError(msg)
+
+
+def set_config_defaults():
+    """This method updates all configuration default values."""
+    set_cors_middleware_defaults()
+
+
+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=['Content-MD5',
+                                    'X-Image-Meta-Checksum',
+                                    'X-Storage-Token',
+                                    'Accept-Encoding',
+                                    'X-Auth-Token',
+                                    'X-Identity-Status',
+                                    'X-Roles',
+                                    'X-Service-Catalog',
+                                    'X-User-Id',
+                                    'X-Tenant-Id',
+                                    'X-OpenStack-Request-ID'],
+                     expose_headers=['X-Image-Meta-Checksum',
+                                     'X-Auth-Token',
+                                     'X-Subject-Token',
+                                     'X-Service-Token',
+                                     'X-OpenStack-Request-ID'],
+                     allow_methods=['GET',
+                                    'PUT',
+                                    'POST',
+                                    'DELETE',
+                                    'PATCH']
+                     )

glance/common/wsgi.py

@@ -47,6 +47,7 @@ import webob.dec
 import webob.exc
 from webob import multidict
 
+from glance.common import config
 from glance.common import exception
 from glance.common import utils
 from glance import i18n
@@ -409,6 +410,7 @@ class Server(object):
 
         # Ensure any logging config changes are picked up
         logging.setup(CONF, 'glance')
+        config.set_config_defaults()
 
         self.configure(old_conf, has_changed)
         self.start_wsgi()

setup.cfg

@@ -45,6 +45,8 @@ oslo.config.opts =
     glance.cache= glance.opts:list_cache_opts
     glance.manage = glance.opts:list_manage_opts
     glance.glare = glance.opts:list_artifacts_opts
+oslo.config.opts.defaults =
+    oslo.middleware.cors = glance.common.config:set_cors_middleware_defaults
 glance.database.migration_backend =
     sqlalchemy = oslo_db.sqlalchemy.migration
 glance.database.metadata_backend =