# -*- encoding: utf-8 -*- # # 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 oslo_config import cfg from oslo_middleware import base OPTS = [ cfg.BoolOpt('enable_proxy_headers_parsing', default=False, help="Whether the application is behind a proxy or not. " "This determines if the middleware should parse the " "headers or not.") ] class HTTPProxyToWSGI(base.ConfigurableMiddleware): """HTTP proxy to WSGI termination middleware. This middleware overloads WSGI environment variables with the one provided by the remote HTTP reverse proxy. """ def __init__(self, application, *args, **kwargs): super(HTTPProxyToWSGI, self).__init__(application, *args, **kwargs) self.oslo_conf.register_opts(OPTS, group='oslo_middleware') @staticmethod def _parse_rfc7239_header(header): """Parses RFC7239 Forward headers. e.g. for=192.0.2.60;proto=http, for=192.0.2.60;by=203.0.113.43 """ result = [] for proxy in header.split(","): entry = {} for d in proxy.split(";"): key, _, value = d.partition("=") entry[key.lower().strip()] = value.strip() result.append(entry) return result def process_request(self, req): if not self._conf_get('enable_proxy_headers_parsing'): return fwd_hdr = req.environ.get("HTTP_FORWARDED") if fwd_hdr: proxies = self._parse_rfc7239_header(fwd_hdr) # Let's use the value from the first proxy if proxies: proxy = proxies[0] forwarded_proto = proxy.get("proto") if forwarded_proto: req.environ['wsgi.url_scheme'] = forwarded_proto forwarded_host = proxy.get("host") if forwarded_host: req.environ['HTTP_HOST'] = forwarded_host forwarded_for = proxy.get("for") if forwarded_for: req.environ['REMOTE_ADDR'] = forwarded_for else: # World before RFC7239 forwarded_proto = req.environ.get("HTTP_X_FORWARDED_PROTO") if forwarded_proto: req.environ['wsgi.url_scheme'] = forwarded_proto forwarded_host = req.environ.get("HTTP_X_FORWARDED_HOST") if forwarded_host: req.environ['HTTP_HOST'] = forwarded_host forwarded_for = req.environ.get("HTTP_X_FORWARDED_FOR") if forwarded_for: req.environ['REMOTE_ADDR'] = forwarded_for v = req.environ.get("HTTP_X_FORWARDED_PREFIX") if v: req.environ['SCRIPT_NAME'] = v + req.environ['SCRIPT_NAME']