nova/nova/api/openstack/__init__.py

346 lines
13 KiB
Python

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.
"""
WSGI middleware for OpenStack API controllers.
"""
from oslo_log import log as logging
import routes
import stevedore
import webob.dec
import webob.exc
from nova.api.openstack import wsgi
import nova.conf
from nova.i18n import _LE
from nova.i18n import _LI
from nova.i18n import _LW
from nova.i18n import translate
from nova import notifications
from nova import utils
from nova import wsgi as base_wsgi
LOG = logging.getLogger(__name__)
CONF = nova.conf.CONF
class FaultWrapper(base_wsgi.Middleware):
"""Calls down the middleware stack, making exceptions into faults."""
_status_to_type = {}
@staticmethod
def status_to_type(status):
if not FaultWrapper._status_to_type:
for clazz in utils.walk_class_hierarchy(webob.exc.HTTPError):
FaultWrapper._status_to_type[clazz.code] = clazz
return FaultWrapper._status_to_type.get(
status, webob.exc.HTTPInternalServerError)()
def _error(self, inner, req):
LOG.exception(_LE("Caught error: %s"), inner)
safe = getattr(inner, 'safe', False)
headers = getattr(inner, 'headers', None)
status = getattr(inner, 'code', 500)
if status is None:
status = 500
msg_dict = dict(url=req.url, status=status)
LOG.info(_LI("%(url)s returned with HTTP %(status)d"), msg_dict)
outer = self.status_to_type(status)
if headers:
outer.headers = headers
# NOTE(johannes): We leave the explanation empty here on
# purpose. It could possibly have sensitive information
# that should not be returned back to the user. See
# bugs 868360 and 874472
# NOTE(eglynn): However, it would be over-conservative and
# inconsistent with the EC2 API to hide every exception,
# including those that are safe to expose, see bug 1021373
if safe:
user_locale = req.best_match_language()
inner_msg = translate(inner.message, user_locale)
outer.explanation = '%s: %s' % (inner.__class__.__name__,
inner_msg)
notifications.send_api_fault(req.url, status, inner)
return wsgi.Fault(outer)
@webob.dec.wsgify(RequestClass=wsgi.Request)
def __call__(self, req):
try:
return req.get_response(self.application)
except Exception as ex:
return self._error(ex, req)
class LegacyV2CompatibleWrapper(base_wsgi.Middleware):
def _filter_request_headers(self, req):
"""For keeping same behavior with v2 API, ignores microversions
HTTP headers X-OpenStack-Nova-API-Version and OpenStack-API-Version
in the request.
"""
if wsgi.API_VERSION_REQUEST_HEADER in req.headers:
del req.headers[wsgi.API_VERSION_REQUEST_HEADER]
if wsgi.LEGACY_API_VERSION_REQUEST_HEADER in req.headers:
del req.headers[wsgi.LEGACY_API_VERSION_REQUEST_HEADER]
return req
def _filter_response_headers(self, response):
"""For keeping same behavior with v2 API, filter out microversions
HTTP header and microversions field in header 'Vary'.
"""
if wsgi.API_VERSION_REQUEST_HEADER in response.headers:
del response.headers[wsgi.API_VERSION_REQUEST_HEADER]
if wsgi.LEGACY_API_VERSION_REQUEST_HEADER in response.headers:
del response.headers[wsgi.LEGACY_API_VERSION_REQUEST_HEADER]
if 'Vary' in response.headers:
vary_headers = response.headers['Vary'].split(',')
filtered_vary = []
for vary in vary_headers:
vary = vary.strip()
if (vary == wsgi.API_VERSION_REQUEST_HEADER or
vary == wsgi.LEGACY_API_VERSION_REQUEST_HEADER):
continue
filtered_vary.append(vary)
if filtered_vary:
response.headers['Vary'] = ','.join(filtered_vary)
else:
del response.headers['Vary']
return response
@webob.dec.wsgify(RequestClass=wsgi.Request)
def __call__(self, req):
req.set_legacy_v2()
req = self._filter_request_headers(req)
response = req.get_response(self.application)
return self._filter_response_headers(response)
class APIMapper(routes.Mapper):
def routematch(self, url=None, environ=None):
if url == "":
result = self._match("", environ)
return result[0], result[1]
return routes.Mapper.routematch(self, url, environ)
def connect(self, *args, **kargs):
# NOTE(vish): Default the format part of a route to only accept json
# and xml so it doesn't eat all characters after a '.'
# in the url.
kargs.setdefault('requirements', {})
if not kargs['requirements'].get('format'):
kargs['requirements']['format'] = 'json|xml'
return routes.Mapper.connect(self, *args, **kargs)
class ProjectMapper(APIMapper):
def resource(self, member_name, collection_name, **kwargs):
# NOTE(sdague): project_id parameter is only valid if its hex
# or hex + dashes (note, integers are a subset of this). This
# is required to hand our overlaping routes issues.
project_id_regex = '[0-9a-f\-]+'
if CONF.osapi_v21.project_id_regex:
project_id_regex = CONF.osapi_v21.project_id_regex
project_id_token = '{project_id:%s}' % project_id_regex
if 'parent_resource' not in kwargs:
kwargs['path_prefix'] = '%s/' % project_id_token
else:
parent_resource = kwargs['parent_resource']
p_collection = parent_resource['collection_name']
p_member = parent_resource['member_name']
kwargs['path_prefix'] = '%s/%s/:%s_id' % (
project_id_token,
p_collection,
p_member)
routes.Mapper.resource(
self,
member_name,
collection_name,
**kwargs)
# while we are in transition mode, create additional routes
# for the resource that do not include project_id.
if 'parent_resource' not in kwargs:
del kwargs['path_prefix']
else:
parent_resource = kwargs['parent_resource']
p_collection = parent_resource['collection_name']
p_member = parent_resource['member_name']
kwargs['path_prefix'] = '%s/:%s_id' % (p_collection,
p_member)
routes.Mapper.resource(self, member_name,
collection_name,
**kwargs)
class PlainMapper(APIMapper):
def resource(self, member_name, collection_name, **kwargs):
if 'parent_resource' in kwargs:
parent_resource = kwargs['parent_resource']
p_collection = parent_resource['collection_name']
p_member = parent_resource['member_name']
kwargs['path_prefix'] = '%s/:%s_id' % (p_collection, p_member)
routes.Mapper.resource(self, member_name,
collection_name,
**kwargs)
class APIRouterV21(base_wsgi.Router):
"""Routes requests on the OpenStack v2.1 API to the appropriate controller
and method.
"""
@classmethod
def factory(cls, global_config, **local_config):
"""Simple paste factory, :class:`nova.wsgi.Router` doesn't have one."""
return cls()
@staticmethod
def api_extension_namespace():
return 'nova.api.v21.extensions'
def __init__(self):
def _check_load_extension(ext):
return self._register_extension(ext)
self.api_extension_manager = stevedore.enabled.EnabledExtensionManager(
namespace=self.api_extension_namespace(),
check_func=_check_load_extension,
invoke_on_load=True,
invoke_kwds={"extension_info": self.loaded_extension_info})
mapper = ProjectMapper()
self.resources = {}
# NOTE(cyeoh) Core API support is rewritten as extensions
# but conceptually still have core
if list(self.api_extension_manager):
# NOTE(cyeoh): Stevedore raises an exception if there are
# no plugins detected. I wonder if this is a bug.
self._register_resources_check_inherits(mapper)
self.api_extension_manager.map(self._register_controllers)
LOG.info(_LI("Loaded extensions: %s"),
sorted(self.loaded_extension_info.get_extensions().keys()))
super(APIRouterV21, self).__init__(mapper)
def _register_resources_list(self, ext_list, mapper):
for ext in ext_list:
self._register_resources(ext, mapper)
def _register_resources_check_inherits(self, mapper):
ext_has_inherits = []
ext_no_inherits = []
for ext in self.api_extension_manager:
for resource in ext.obj.get_resources():
if resource.inherits:
ext_has_inherits.append(ext)
break
else:
ext_no_inherits.append(ext)
self._register_resources_list(ext_no_inherits, mapper)
self._register_resources_list(ext_has_inherits, mapper)
@property
def loaded_extension_info(self):
raise NotImplementedError()
def _register_extension(self, ext):
raise NotImplementedError()
def _register_resources(self, ext, mapper):
"""Register resources defined by the extensions
Extensions define what resources they want to add through a
get_resources function
"""
handler = ext.obj
LOG.debug("Running _register_resources on %s", ext.obj)
for resource in handler.get_resources():
LOG.debug('Extended resource: %s', resource.collection)
inherits = None
if resource.inherits:
inherits = self.resources.get(resource.inherits)
if not resource.controller:
resource.controller = inherits.controller
wsgi_resource = wsgi.ResourceV21(resource.controller,
inherits=inherits)
self.resources[resource.collection] = wsgi_resource
kargs = dict(
controller=wsgi_resource,
collection=resource.collection_actions,
member=resource.member_actions)
if resource.parent:
kargs['parent_resource'] = resource.parent
# non core-API plugins use the collection name as the
# member name, but the core-API plugins use the
# singular/plural convention for member/collection names
if resource.member_name:
member_name = resource.member_name
else:
member_name = resource.collection
mapper.resource(member_name, resource.collection,
**kargs)
if resource.custom_routes_fn:
resource.custom_routes_fn(mapper, wsgi_resource)
def _register_controllers(self, ext):
"""Register controllers defined by the extensions
Extensions define what resources they want to add through
a get_controller_extensions function
"""
handler = ext.obj
LOG.debug("Running _register_controllers on %s", ext.obj)
for extension in handler.get_controller_extensions():
ext_name = extension.extension.name
collection = extension.collection
controller = extension.controller
if collection not in self.resources:
LOG.warning(_LW('Extension %(ext_name)s: Cannot extend '
'resource %(collection)s: No such resource'),
{'ext_name': ext_name, 'collection': collection})
continue
LOG.debug('Extension %(ext_name)s extending resource: '
'%(collection)s',
{'ext_name': ext_name, 'collection': collection})
resource = self.resources[collection]
resource.register_actions(controller)
resource.register_extensions(controller)