118 lines
4.0 KiB
Python
118 lines
4.0 KiB
Python
# Copyright 2011 OpenStack Foundation
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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"""
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A filter middleware that inspects the requested URI for a version string
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and/or Accept headers and attempts to negotiate an API controller to
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return
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"""
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from oslo_config import cfg
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from oslo_log import log as logging
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from glance.api import versions
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from glance.common import wsgi
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CONF = cfg.CONF
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LOG = logging.getLogger(__name__)
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class VersionNegotiationFilter(wsgi.Middleware):
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def __init__(self, app):
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self.versions_app = versions.Controller()
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self.allowed_versions = None
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self.vnd_mime_type = 'application/vnd.openstack.images-'
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super(VersionNegotiationFilter, self).__init__(app)
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def process_request(self, req):
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"""Try to find a version first in the accept header, then the URL"""
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args = {'method': req.method, 'path': req.path, 'accept': req.accept}
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LOG.debug("Determining version of request: %(method)s %(path)s "
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"Accept: %(accept)s", args)
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# If the request is for /versions, just return the versions container
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if req.path_info_peek() == "versions":
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return self.versions_app.index(req, explicit=True)
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accept = str(req.accept)
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if accept.startswith(self.vnd_mime_type):
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LOG.debug("Using media-type versioning")
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token_loc = len(self.vnd_mime_type)
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req_version = accept[token_loc:]
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else:
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LOG.debug("Using url versioning")
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# Remove version in url so it doesn't conflict later
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req_version = self._pop_path_info(req)
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try:
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version = self._match_version_string(req_version)
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except ValueError:
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LOG.debug("Unknown version. Returning version choices.")
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return self.versions_app
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req.environ['api.version'] = version
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req.path_info = ''.join(('/v', str(version), req.path_info))
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LOG.debug("Matched version: v%d", version)
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LOG.debug('new path %s', req.path_info)
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return None
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def _get_allowed_versions(self):
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allowed_versions = {}
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if CONF.enable_v2_api:
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allowed_versions['v2'] = 2
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allowed_versions['v2.0'] = 2
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allowed_versions['v2.1'] = 2
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allowed_versions['v2.2'] = 2
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allowed_versions['v2.3'] = 2
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allowed_versions['v2.4'] = 2
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allowed_versions['v2.5'] = 2
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allowed_versions['v2.6'] = 2
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return allowed_versions
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def _match_version_string(self, subject):
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"""
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Given a string, tries to match a major and/or
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minor version number.
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:param subject: The string to check
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:returns: version found in the subject
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:raises ValueError: if no acceptable version could be found
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"""
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if self.allowed_versions is None:
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self.allowed_versions = self._get_allowed_versions()
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if subject in self.allowed_versions:
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return self.allowed_versions[subject]
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else:
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raise ValueError()
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def _pop_path_info(self, req):
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"""
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'Pops' off the next segment of PATH_INFO, returns the popped
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segment. Do NOT push it onto SCRIPT_NAME.
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"""
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path = req.path_info
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if not path:
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return None
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while path.startswith('/'):
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path = path[1:]
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idx = path.find('/')
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if idx == -1:
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idx = len(path)
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r = path[:idx]
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req.path_info = path[idx:]
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return r
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