vmware-nsx/neutron/api/v2/resource.py
Luis A. Garcia d12fcadaa0 Enable localizable REST API responses via the Accept-Language header
Add support for doing language resolution for a request, based on the
Accept-Language HTTP header. Using the lazy gettext functionality, from
oslo gettextutils, it is possible to use the resolved language to
translate exception messages to the user requested language and
return that translation from the API.

Partially implements bp user-locale-api.

Change-Id: I63edc8463836bfff257daa8a2c66ed5d3a444254
2013-08-07 21:19:25 +00:00

156 lines
6.1 KiB
Python

# Copyright 2012 OpenStack Foundation.
# 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.
"""
Utility methods for working with WSGI servers redux
"""
import netaddr
import webob.dec
import webob.exc
from neutron.api.v2 import attributes
from neutron.common import exceptions
from neutron.openstack.common import gettextutils
from neutron.openstack.common import log as logging
from neutron import wsgi
LOG = logging.getLogger(__name__)
class Request(wsgi.Request):
pass
def Resource(controller, faults=None, deserializers=None, serializers=None):
"""Represents an API entity resource and the associated serialization and
deserialization logic
"""
xml_deserializer = wsgi.XMLDeserializer(attributes.get_attr_metadata())
default_deserializers = {'application/xml': xml_deserializer,
'application/json': wsgi.JSONDeserializer()}
xml_serializer = wsgi.XMLDictSerializer(attributes.get_attr_metadata())
default_serializers = {'application/xml': xml_serializer,
'application/json': wsgi.JSONDictSerializer()}
format_types = {'xml': 'application/xml',
'json': 'application/json'}
action_status = dict(create=201, delete=204)
default_deserializers.update(deserializers or {})
default_serializers.update(serializers or {})
deserializers = default_deserializers
serializers = default_serializers
faults = faults or {}
@webob.dec.wsgify(RequestClass=Request)
def resource(request):
route_args = request.environ.get('wsgiorg.routing_args')
if route_args:
args = route_args[1].copy()
else:
args = {}
# NOTE(jkoelker) by now the controller is already found, remove
# it from the args if it is in the matchdict
args.pop('controller', None)
fmt = args.pop('format', None)
action = args.pop('action', None)
content_type = format_types.get(fmt,
request.best_match_content_type())
language = request.best_match_language()
deserializer = deserializers.get(content_type)
serializer = serializers.get(content_type)
try:
if request.body:
args['body'] = deserializer.deserialize(request.body)['body']
method = getattr(controller, action)
result = method(request=request, **args)
except (exceptions.NeutronException,
netaddr.AddrFormatError) as e:
LOG.exception(_('%s failed'), action)
e = translate(e, language)
body = serializer.serialize({'NeutronError': e})
kwargs = {'body': body, 'content_type': content_type}
for fault in faults:
if isinstance(e, fault):
raise faults[fault](**kwargs)
raise webob.exc.HTTPInternalServerError(**kwargs)
except webob.exc.HTTPException as e:
LOG.exception(_('%s failed'), action)
translate(e, language)
e.body = serializer.serialize({'NeutronError': e})
e.content_type = content_type
raise
except NotImplementedError as e:
e = translate(e, language)
# NOTE(armando-migliaccio): from a client standpoint
# it makes sense to receive these errors, because
# extensions may or may not be implemented by
# the underlying plugin. So if something goes south,
# because a plugin does not implement a feature,
# returning 500 is definitely confusing.
body = serializer.serialize(
{'NotImplementedError': e.message})
kwargs = {'body': body, 'content_type': content_type}
raise webob.exc.HTTPNotImplemented(**kwargs)
except Exception as e:
# NOTE(jkoelker) Everyting else is 500
LOG.exception(_('%s failed'), action)
# Do not expose details of 500 error to clients.
msg = _('Request Failed: internal server error while '
'processing your request.')
msg = translate(msg, language)
body = serializer.serialize({'NeutronError': msg})
kwargs = {'body': body, 'content_type': content_type}
raise webob.exc.HTTPInternalServerError(**kwargs)
status = action_status.get(action, 200)
body = serializer.serialize(result)
# NOTE(jkoelker) Comply with RFC2616 section 9.7
if status == 204:
content_type = ''
body = None
return webob.Response(request=request, status=status,
content_type=content_type,
body=body)
return resource
def translate(translatable, locale):
"""Translates the object to the given locale.
If the object is an exception its translatable elements are translated
in place, if the object is a translatable string it is translated and
returned. Otherwise, the object is returned as-is.
:param translatable: the object to be translated
:param locale: the locale to translate to
:returns: the translated object, or the object as-is if it
was not translated
"""
localize = gettextutils.get_localized_message
if isinstance(translatable, Exception):
translatable.message = localize(translatable.message, locale)
if isinstance(translatable, webob.exc.HTTPError):
translatable.detail = localize(translatable.detail, locale)
return translatable
return localize(translatable, locale)