deb-murano/murano/api/middleware/fault.py
Ravi Shekhar Jethani 782808db60 Replace unicode with six.text_type
The Unicode type is 'unicode' in Python 2 and 'str' on Python 3.
This patch replaces unicode with six.text_type to make Murano
more compatible with Python 3. Also it replaces the tuple
'(str, unicode)' with six.string_types for instance comparision.

Blueprint murano-python-3-support

Change-Id: I4db27afdb556ec30dd36d7d4e170055274edfa8b
2015-12-28 05:07:08 -08:00

131 lines
3.9 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 six
import sys
import traceback
from oslo_config import cfg
import webob
from murano.common import wsgi
from murano.packages import exceptions as pkg_exc
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 = six.text_type(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)))