node.js - Proxy with express.js

Question

To avoid same-domain AJAX issues, I want my node.js web server to forward all requests from URL /api/BLABLA to another server, for example other_domain.com:3000/BLABLA, and return to user the same thing that this remote server returned, transparently.

All other URLs (beside /api/*) are to be served directly, no proxying.

How do I achieve this with node.js + express.js? Can you give a simple code example?

(both the web server and the remote 3000 server are under my control, both running node.js with express.js)

---

So far I found this https://github.com/http-party/node-http-proxy , but reading the documentation there didn't make me any wiser. I ended up with

var proxy = new httpProxy.RoutingProxy();
app.all("/api/*", function(req, res) {
    console.log("old request url " + req.url)
    req.url = '/' + req.url.split('/').slice(2).join('/'); // remove the '/api' part
    console.log("new request url " + req.url)
    proxy.proxyRequest(req, res, {
        host: "other_domain.com",
        port: 3000
    });
});

but nothing is returned to the original web server (or to the end user), so no luck.

Answer 1

request has been deprecated as of February 2020, I'll leave the answer below for historical reasons, but please consider moving to an alternative listed in this issue.

Archive

I did something similar but I used request instead:

var request = require('request');
app.get('/', function(req,res) {
  //modify the url in any way you want
  var newurl = 'http://google.com/';
  request(newurl).pipe(res);
});

I hope this helps, took me a while to realize that I could do this :)