Proxying a request to a backend

proxy.go

package main

import (
	"net/http"
	"net/http/httputil"
	"net/url"

	"github.com/gorilla/mux"
)

func report(r *http.Request) {
	r.Host = "localhost:8888"
	r.URL.Host = r.Host
	r.URL.Scheme = "http"
}

func main() {
	proxy := httputil.NewSingleHostReverseProxy(&url.URL{
		Scheme: "http",
		Host:   "localhost:8888",
	})
	proxy.Director = report

	r := mux.NewRouter()

	r.Handle("/hello", proxy)
	r.Handle("/hello/{user}", proxy)
	r.Handle("/bye", proxy)

	http.ListenAndServe(":8181", r)
}

proxy_target.py

#!/usr/bin/env python

import tornado.httpserver
import tornado.ioloop
import tornado.options
import tornado.web

from tornado.options import define, options

define("port", default=8888, help="run on the given port", type=int)


class MainHandler(tornado.web.RequestHandler):
    def get(self, name=None):
        print("Header")
        print(self.request.headers.get('X-MyHeader'))
        self.set_header('User', 'Paul')
        if name:
            self.write("Hello, {}".format(name))
        else:
            self.write("Hello, world")

class ByeHandler(tornado.web.RequestHandler):
    def get(self):
        self.write("Bye Bye, world")

def main():
    tornado.options.parse_command_line()
    application = tornado.web.Application([
        (r"/hello", MainHandler),
        (r"/hello/([^/]+)", MainHandler),
        (r'/bye', ByeHandler),
    ])
    http_server = tornado.httpserver.HTTPServer(application)
    http_server.listen(options.port)
    tornado.ioloop.IOLoop.current().start()


if __name__ == "__main__":
    main()