deb-murano/murano/api/middleware/fault.py
Doug Hellmann 21a14acba4 Drop use of 'oslo' namespace package
The Oslo libraries have moved all of their code out of the 'oslo'
namespace package into per-library packages. The namespace package was
retained during kilo for backwards compatibility, but will be removed by
the liberty-2 milestone. This change removes the use of the namespace
package, replacing it with the new package names.

The patches in the libraries will be put on hold until application
patches have landed, or L2, whichever comes first. At that point, new
versions of the libraries without namespace packages will be released as
a major version update.

Please merge this patch, or an equivalent, before L2 to avoid problems
with those library releases.

Blueprint: remove-namespace-packages
https://blueprints.launchpad.net/oslo-incubator/+spec/remove-namespace-packages

Change-Id: I975592f3694be42d52685ebf606f6d3012caf1a8
2015-04-28 20:21:22 +00:00

132 lines
4.0 KiB
Python

# 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.
"""A middleware that turns exceptions into parsable string. Inspired by
Cinder's faultwrapper
"""
import sys
import traceback
from oslo_config import cfg
import webob
from murano.common import wsgi
from murano.packages import exceptions as pkg_exc
cfg.CONF.import_opt('debug', 'murano.openstack.common.log')
class HTTPExceptionDisguise(Exception):
"""Disguises HTTP exceptions so they can be handled by the webob fault
application in the wsgi pipeline.
"""
def __init__(self, exception):
self.exc = exception
self.tb = sys.exc_info()[2]
class Fault(object):
def __init__(self, error):
self.error = error
@webob.dec.wsgify(RequestClass=wsgi.Request)
def __call__(self, req):
if req.content_type == 'application/xml':
serializer = wsgi.XMLDictSerializer()
else:
serializer = wsgi.JSONDictSerializer()
resp = webob.Response(request=req)
default_webob_exc = webob.exc.HTTPInternalServerError()
resp.status_code = self.error.get('code', default_webob_exc.code)
serializer.default(resp, self.error)
return resp
class FaultWrapper(wsgi.Middleware):
"""Replace error body with something the client can parse."""
@classmethod
def factory(cls, global_conf, **local_conf):
def filter(app):
return cls(app)
return filter
error_map = {
'ValueError': webob.exc.HTTPBadRequest,
'LookupError': webob.exc.HTTPNotFound,
'PackageClassLoadError': webob.exc.HTTPBadRequest,
'PackageUILoadError': webob.exc.HTTPBadRequest,
'PackageLoadError': webob.exc.HTTPBadRequest,
'PackageFormatError': webob.exc.HTTPBadRequest,
}
def _map_exception_to_error(self, class_exception):
if class_exception == Exception:
return webob.exc.HTTPInternalServerError
if class_exception.__name__ not in self.error_map:
return self._map_exception_to_error(class_exception.__base__)
return self.error_map[class_exception.__name__]
def _error(self, ex):
trace = None
webob_exc = None
if isinstance(ex, HTTPExceptionDisguise):
# An HTTP exception was disguised so it could make it here
# let's remove the disguise and set the original HTTP exception
if cfg.CONF.debug:
trace = ''.join(traceback.format_tb(ex.tb))
ex = ex.exc
webob_exc = ex
ex_type = ex.__class__.__name__
full_message = unicode(ex)
if full_message.find('\n') > -1:
message, msg_trace = full_message.split('\n', 1)
else:
msg_trace = traceback.format_exc()
message = full_message
if isinstance(ex, pkg_exc.PackageException):
message = ex.message
if cfg.CONF.debug and not trace:
trace = msg_trace
if not webob_exc:
webob_exc = self._map_exception_to_error(ex.__class__)
error = {
'code': webob_exc.code,
'title': webob_exc.title,
'explanation': webob_exc.explanation,
'error': {
'message': message,
'type': ex_type,
'traceback': trace,
}
}
return error
def process_request(self, req):
try:
return req.get_response(self.application)
except Exception as exc:
return req.get_response(Fault(self._error(exc)))