swift/swift/common/middleware/catch_errors.py

64 lines
2.2 KiB
Python

# Copyright (c) 2010-2011 OpenStack, LLC.
#
# 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.
from eventlet import Timeout
from webob import Request
from webob.exc import HTTPServerError
import uuid
from swift.common.utils import get_logger
class CatchErrorMiddleware(object):
"""
Middleware that provides high-level error handling and ensures that a
transaction id will be set for every request.
"""
def __init__(self, app, conf):
self.app = app
self.logger = get_logger(conf, log_route='catch-errors')
def __call__(self, env, start_response):
"""
If used, this should be the first middleware in pipeline.
"""
trans_id = 'tx' + uuid.uuid4().hex
env['swift.trans_id'] = trans_id
self.logger.txn_id = trans_id
try:
def my_start_response(status, response_headers, exc_info=None):
trans_header = ('x-trans-id', trans_id)
response_headers.append(trans_header)
return start_response(status, response_headers, exc_info)
return self.app(env, my_start_response)
except (Exception, Timeout), err:
self.logger.exception(_('Error: %s'), err)
resp = HTTPServerError(request=Request(env),
body='An error occurred',
content_type='text/plain')
resp.headers['x-trans-id'] = trans_id
return resp(env, start_response)
def filter_factory(global_conf, **local_conf):
conf = global_conf.copy()
conf.update(local_conf)
def except_filter(app):
return CatchErrorMiddleware(app, conf)
return except_filter