beginnings of a proxy for web2py. See http://trac.sahanapy.org/wiki/BluePrintGISProxy for more

web2py_proxy.py

# coding: utf8
def index():
    """Based on http://trac.openlayers.org/browser/trunk/openlayers/examples/proxy.cgi
    This is a blind proxy that we use to get around browser
    restrictions that prevent the Javascript from loading pages not on the
    same server as the Javascript.  This has several problems: it's less
    efficient, it might break some sites, and it's a security risk because
    people can use this proxy to browse the web and possibly do bad stuff
    with it.  It only loads pages via http and https, but it can load any
    content type. It supports GET and POST requests."""
    
    import urllib2
    import cgi
    import sys, os
    
    # prevent Open Proxy abuse
    
    allowedHosts = ['www.openlayers.org', 'openlayers.org',
                    'labs.metacarta.com', 'world.freemap.in',
                    'prototype.openmnnd.org', 'geo.openplans.org',
                    'sigma.openplans.org', 'demo.opengeo.org',
                    'www.openstreetmap.org', 'sample.avencia.com',
                    'v-swe.uni-muenster.de:8080']
    
    method = request['wsgi'].environ['REQUEST_METHOD']
    
    if method == "POST":
        qs = request['wsgi'].environ["QUERY_STRING"]
        
        d = cgi.parse_qs(qs)
        if d.has_key("url"):
            url = d["url"][0]
        else:
            url = "http://www.openlayers.org"
    else:
        fs = cgi.FieldStorage()
        url = fs.getvalue('url', "http://www.openlayers.org")
    
    try:
        host = url.split("/")[2]
        if allowedHosts and not host in allowedHosts:
            msg = "Status: 502 Bad Gateway\n"
            msg += "Content-Type: text/plain\n\n"
            msg += "This proxy does not allow you to access that location (%s).\n\n" % (host,)
           
            msg += os.environ
            return msg
     
        elif url.startswith("http://") or url.startswith("https://"):
            if method == "POST":
                length = int(request['wsgi'].environ["CONTENT_LENGTH"])
                headers = {"Content-Type": request['wsgi'].environ["CONTENT_TYPE"]}
                body = request.body.read(length)                
                r = urllib2.Request(url, body, headers)
                y = urllib2.urlopen(r)
            else:
                y = urllib2.urlopen(url)
           
            # print content type header
            # TODO: this doesn't work in web2py, need to figure out how that happens?
            #i = y.info()
            #if i.has_key("Content-Type"):
            #    msg = "Content-Type: %s" % (i["Content-Type"])
            #else:
            #    msg = "Content-Type: text/plain"
           
            #msg += "\n" + y.read()
           
            msg = y.read()
            y.close()
            return msg
        else:
            msg = "Content-Type: text/plain\n\n"
           
            msg += "Illegal request."
            return msg
    
    except Exception, E:
        msg = "Status: 500 Unexpected Error\n"
        msg += "Content-Type: text/plain\n\n"
        msg += "Some unexpected error occurred. Error text was:", E
        return msg