tornado_proxy.py

class ForwardingRequestHandler (tornado.web.RequestHandler): 

    def handle_response(self, response): 
        if response.error and not isinstance(response.error, 
tornado.httpclient.HTTPError): 
            note("response has error %s", response.error) 
            self.set_status(500) 
            self.write("Internal server error:\n" + 
str(response.error)) 
            self.finish() 
        else: 
            self.set_status(response.code) 
            for header in ("Date", "Cache-Control", "Server", "Content- 
Type", "Location"): 
                v = response.headers.get(header) 
                if v: 
                    self.set_header(header, v) 
            if response.body: 
                self.write(response.body) 
            self.finish() 

    def forward(self, port=None, host=None): 
        try: 
            tornado.httpclient.AsyncHTTPClient().fetch( 
                tornado.httpclient.HTTPRequest( 
                    url="%s://%s:%s%s" % ( 
                        self.request.protocol, host or "127.0.0.1", 
port or 80, self.request.uri), 
                    method=self.request.method, 
                    body=self.request.body, 
                    headers=self.request.headers, 
                    follow_redirects=False), 
                self.handle_response) 
        except tornado.httpclient.HTTPError, x: 
            note("tornado signalled HTTPError %s", x) 
            if hasattr(x, response) and x.response: 
                self.handle_response(x.response) 
        except tornado.httpclient.CurlError, x: 
            note("tornado signalled CurlError %s", x) 
            self.set_status(500) 
            self.write("Internal server error:\n" + 
''.join(traceback.format_exception(*sys.exc_info()))) 
            self.finish() 
        except: 
            self.set_status(500) 
            self.write("Internal server error:\n" + 
''.join(traceback.format_exception(*sys.exc_info()))) 
            self.finish()