Node-http-proxy: Unable to set cookies / write headers from proxy

Created on 28 Jul 2013 · 6Comments · Source: http-party/node-http-proxy

I am trying to write a header on the response object from within the proxy:

// dependencies
var httpProxy = require('./lib/node-http-proxy'),
    http = require('http');

// 
// Setup proxy server on 8000
//

var server = httpProxy.createServer(function (req, res, proxy) {

  // fetch cookies
  var cookies = {};
  req.headers.cookie && req.headers.cookie.split(';').forEach(function( cookie ) {
    var parts = cookie.split('=');
    cookies[ parts[ 0 ].trim() ] = ( parts[ 1 ] || '' ).trim();
  });

  console.log(cookies);

  // write session cookie
  res.writeHead(200, {
    'Set-Cookie': 'token=12345678'    
  });

  // proxy requests to localhost:9000
  proxy.proxyRequest(req, res, {
    host: 'localhost',
    port: 9000,
  });

});
server.listen(8000);



//
// Dummy target server on port 9000 (echo request)
//
http.createServer(function (req, res) {

 res.write('Echo service: ' + req.url + '\n' + JSON.stringify(req.headers, true, 2));

  res.end();

}).listen(9000);

And http fails with "Cannot write header/s after they have been written." Reverse proxy documentation says nothing about setting cookies. What am I doing wrong?

feature-request

Source

robertjchristian

Most helpful comment

@aiboy, I tried your solution on a recent boilerplate (since that was written in 2013) and while I'm able to modify/override any header property, I can't get a cookie to save under resources, jessionid in particular.

adi518 on 24 Apr 2016

👍3

All 6 comments

This isn't going to work because proxy.proxyRequest calls res.writeHead too (and res.writeHead flushes headers). I don't think there's a way to walk this around so I'm going to leave this open as a feature request.

mmalecki on 29 Jul 2013

I suggest to close this issue since we can quite easily achieve replacing of headers by "emulating" express middlewere and replacing setHeader.

var http = require('http'),
    httpProxy = require('http-proxy'),
    static = require('node-static');

httpProxy.createServer(function(req, res, next){

    //this code will replace all set-cookie headers to ONE header that u want
    //if there will be 2 set-cookie headers
    //result will be 1 set-cookie:a=b header
    var _setHeader = res.setHeader.bind(res);
    res.setHeader = function(name, value) {
        if (name && name.toLowerCase() == "set-cookie") {
            return _setHeader("set-cookie", "a=b");
        } else {
            return _setHeader(name, value);
        }
    }
    next();

},function (req, res, proxy) {

    //usuall code
    proxy.proxyRequest(req, res, {
        host: 'someserver.com',
        port: 80
    }); 

}).listen(8000);

obenjiro on 3 Aug 2013

adi518 on 24 Apr 2016

👍3

Is there any solution with cookies received from a proxied subdomain, which also contain the "domain" attribute?

We cannot authenticate from localhost (we are using webpack-dev-server) because of this problem. The 'domain' attribute for the received cookie is different from 'localhost' (obviously) and this causes the authentication to not work on the next call.

Is there any solution or trick to this problem? (i.e. automatically changing the "domain" attribute value through a proxy rule or code?)

Thanks!