pagure/pagure/proxy.py

# -*- coding: utf-8 -*-
#
# Copyright © 2014  Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions
# of the GNU General Public License v.2, or (at your option) any later
# version.  This program is distributed in the hope that it will be
# useful, but WITHOUT ANY WARRANTY expressed or implied, including the
# implied warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR
# PURPOSE.  See the GNU General Public License for more details.  You
# should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# Any Red Hat trademarks that are incorporated in the source
# code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission
# of Red Hat, Inc.
#

"""
Makes pagure an application behind a reverse proxy and thus ensure the
redirects are using ``https``.

Source: http://flask.pocoo.org/snippets/35/ by Peter Hansen
"""

from __future__ import absolute_import, unicode_literals


class ReverseProxied(object):  # pragma: no cover
    """Wrap the application in this middleware and configure the
    front-end server to add these headers, to let you quietly bind
    this to a URL other than / and to an HTTP scheme that is
    different than what is used locally.

    In nginx:
    location /myprefix {
        proxy_pass http://192.168.0.1:5001;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Scheme $scheme;
        proxy_set_header X-Script-Name /myprefix;
        }
    In apache:
        RequestHeader set X-Forwarded-Scheme https early
        RequestHeader set X-Scheme https early
        RequestHeader add X-Script-Name /myprefix early
        RequestHeader set X-Forwarded-Proto https early

    :param app: the WSGI application
    """

    def __init__(self, app):
        self.app = app

    def __call__(self, environ, start_response):
        script_name = environ.get("HTTP_X_SCRIPT_NAME", "")
        if script_name:
            environ["SCRIPT_NAME"] = script_name
            path_info = environ["PATH_INFO"]
            if path_info.startswith(script_name):
                environ["PATH_INFO"] = path_info[len(script_name) :]

        server = environ.get("HTTP_X_FORWARDED_HOST", "")
        if server:
            environ["HTTP_HOST"] = server

        scheme = environ.get("HTTP_X_SCHEME", "")
        if scheme:
            environ["wsgi.url_scheme"] = scheme

        return self.app(environ, start_response)