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OpenStack Study: middleware.py**** CubicPower OpenStack Study ****
# vim: tabstop=4 shiftwidth=4 softtabstop=4 # Copyright 2012 United States Government as represented by the # Administrator of the National Aeronautics and Space Administration. # All Rights Reserved. # # Copyright 2012 Nebula, Inc. # # 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. """ Middleware provided and used by Horizon. """ import json import logging import time from django.conf import settings from django.contrib.auth import REDIRECT_FIELD_NAME # noqa from django.contrib.auth.views import redirect_to_login # noqa from django.contrib import messages as django_messages from django import http from django.http import HttpResponseRedirect # noqa from django import shortcuts from django.utils.encoding import iri_to_uri # noqa from django.utils import timezone from django.utils.translation import ugettext_lazy as _ from horizon import exceptions from horizon.utils import functions as utils LOG = logging.getLogger(__name__)
**** CubicPower OpenStack Study **** class HorizonMiddleware(object): """The main Horizon middleware class. Required for use of Horizon.""" logout_reason = None
**** CubicPower OpenStack Study **** def process_request(self, request): """Adds data necessary for Horizon to function to the request.""" # Activate timezone handling tz = request.session.get('django_timezone') if tz: timezone.activate(tz) # Check for session timeout try: timeout = settings.SESSION_TIMEOUT except AttributeError: timeout = 1800 last_activity = request.session.get('last_activity', None) timestamp = int(time.time()) request.horizon = {'dashboard': None, 'panel': None, 'async_messages': []} if not hasattr(request, "user") or not request.user.is_authenticated(): # proceed no further if the current request is already known # not to be authenticated return None # If we use cookie-based sessions, check that the cookie size does not # reach the max size accepted by common web browsers. if ( settings.SESSION_ENGINE == 'django.contrib.sessions.backends.signed_cookies' ): max_cookie_size = getattr( settings, 'SESSION_COOKIE_MAX_SIZE', None) session_cookie_name = getattr( settings, 'SESSION_COOKIE_NAME', None) session_key = request.COOKIES.get(session_cookie_name) if max_cookie_size is not None and session_key is not None: cookie_size = sum(( len(key) + len(value) for key, value in request.COOKIES.iteritems() )) if cookie_size >= max_cookie_size: LOG.error( 'Total Cookie size for user_id: %(user_id)s is ' '%(cookie_size)sB >= %(max_cookie_size)sB. ' 'You need to configure file-based or database-backed ' 'sessions instead of cookie-based sessions: ' 'http://docs.openstack.org/developer/horizon/topics/' 'deployment.html#session-storage' % { 'user_id': request.session.get( 'user_id', 'Unknown'), 'cookie_size': cookie_size, 'max_cookie_size': max_cookie_size, } ) if (isinstance(last_activity, int) and (timestamp - last_activity) > timeout): request.session.pop('last_activity') response = HttpResponseRedirect( '%s?next=%s' % (settings.LOGOUT_URL, request.path)) self.logout_reason = _("Session timed out.") utils.add_logout_reason(request, response, self.logout_reason) return response request.session['last_activity'] = timestamp
**** CubicPower OpenStack Study **** def process_exception(self, request, exception): """Catches internal Horizon exception classes such as NotAuthorized, NotFound and Http302 and handles them gracefully. """ if isinstance(exception, (exceptions.NotAuthorized, exceptions.NotAuthenticated)): auth_url = settings.LOGIN_URL next_url = iri_to_uri(request.get_full_path()) if next_url != auth_url: field_name = REDIRECT_FIELD_NAME else: field_name = None login_url = request.build_absolute_uri(auth_url) response = redirect_to_login(next_url, login_url=login_url, redirect_field_name=field_name) if request.is_ajax(): response_401 = http.HttpResponse(status=401) response_401['X-Horizon-Location'] = response['location'] return response_401 return response # If an internal "NotFound" error gets this far, return a real 404. if isinstance(exception, exceptions.NotFound): raise http.Http404(exception) if isinstance(exception, exceptions.Http302): # TODO(gabriel): Find a way to display an appropriate message to # the user *on* the login form... return shortcuts.redirect(exception.location)
**** CubicPower OpenStack Study **** def process_response(self, request, response): """Convert HttpResponseRedirect to HttpResponse if request is via ajax to allow ajax request to redirect url """ if request.is_ajax() and hasattr(request, 'horizon'): queued_msgs = request.horizon['async_messages'] if type(response) == http.HttpResponseRedirect: # Drop our messages back into the session as per usual so they # don't disappear during the redirect. Not that we explicitly # use django's messages methods here. for tag, message, extra_tags in queued_msgs: getattr(django_messages, tag)(request, message, extra_tags) if response['location'].startswith(settings.LOGOUT_URL): redirect_response = http.HttpResponse(status=401) # This header is used for handling the logout in JS redirect_response['logout'] = True if self.logout_reason is not None: utils.add_logout_reason( request, redirect_response, self.logout_reason) else: redirect_response = http.HttpResponse() # Copy cookies from HttpResponseRedirect towards HttpResponse for cookie_name, cookie in response.cookies.iteritems(): cookie_kwargs = dict(( (key, value) for key, value in cookie.iteritems() if key in ('max_age', 'expires', 'path', 'domain', 'secure', 'httponly') and value )) redirect_response.set_cookie( cookie_name, cookie.value, **cookie_kwargs) redirect_response['X-Horizon-Location'] = response['location'] return redirect_response if queued_msgs: # TODO(gabriel): When we have an async connection to the # client (e.g. websockets) this should be pushed to the # socket queue rather than being sent via a header. # The header method has notable drawbacks (length limits, # etc.) and is not meant as a long-term solution. response['X-Horizon-Messages'] = json.dumps(queued_msgs) return response
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