heat.api.middleware.version_negotiation

Source code for heat.api.middleware.version_negotiation

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#    Licensed under the Apache License, Version 2.0 (the "License"); you may
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#
#         http://www.apache.org/licenses/LICENSE-2.0
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#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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"""Inspects the requested URI for a version string and/or Accept headers.

Also attempts to negotiate an API controller to return.
"""

import re

from oslo_log import log as logging
import webob

from heat.common import wsgi

LOG = logging.getLogger(__name__)


[docs]class VersionNegotiationFilter(wsgi.Middleware): def __init__(self, version_controller, app, conf, **local_conf): self.versions_app = version_controller(conf) self.version_uri_regex = re.compile(r"^v(\d+)\.?(\d+)?") self.conf = conf super(VersionNegotiationFilter, self).__init__(app)
[docs] def process_request(self, req): """Process Accept header or simply return correct API controller. If there is a version identifier in the URI, return the correct API controller, otherwise, if we find an Accept: header, process it """ # See if a version identifier is in the URI passed to # us already. If so, simply return the right version # API controller msg = ("Processing request: %(method)s %(path)s Accept: " "%(accept)s" % {'method': req.method, 'path': req.path, 'accept': req.accept}) LOG.debug(msg) # If the request is for /versions, just return the versions container if req.path_info_peek() in ("versions", ""): return self.versions_app match = self._match_version_string(req.path_info_peek(), req) if match: major_version = req.environ['api.major_version'] minor_version = req.environ['api.minor_version'] if (major_version == 1 and minor_version == 0): LOG.debug("Matched versioned URI. " "Version: %(major_version)d.%(minor_version)d" % {'major_version': major_version, 'minor_version': minor_version}) # Strip the version from the path req.path_info_pop() return None else: LOG.debug("Unknown version in versioned URI: " "%(major_version)d.%(minor_version)d. " "Returning version choices." % {'major_version': major_version, 'minor_version': minor_version}) return self.versions_app accept = str(req.accept) if accept.startswith('application/vnd.openstack.orchestration-'): token_loc = len('application/vnd.openstack.orchestration-') accept_version = accept[token_loc:] match = self._match_version_string(accept_version, req) if match: major_version = req.environ['api.major_version'] minor_version = req.environ['api.minor_version'] if (major_version == 1 and minor_version == 0): LOG.debug("Matched versioned media type. Version: " "%(major_version)d.%(minor_version)d" % {'major_version': major_version, 'minor_version': minor_version}) return None else: LOG.debug("Unknown version in accept header: " "%(major_version)d.%(minor_version)d... " "returning version choices." % {'major_version': major_version, 'minor_version': minor_version}) return self.versions_app else: if req.accept not in ('*/*', ''): LOG.debug("Unknown accept header: %s... " "returning HTTP not found.", req.accept) return webob.exc.HTTPNotFound() return None
def _match_version_string(self, subject, req): """Given a subject, tries to match a major and/or minor version number. If found, sets the api.major_version and api.minor_version environ variables. Returns True if there was a match, false otherwise. :param subject: The string to check :param req: Webob.Request object """ match = self.version_uri_regex.match(subject) if match: major_version, minor_version = match.groups(0) major_version = int(major_version) minor_version = int(minor_version) req.environ['api.major_version'] = major_version req.environ['api.minor_version'] = minor_version return match is not None
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