Proxy websockets connection within webpack-dev-server

Question

Is it possible to proxy websocket connections within the webpack dev server? I know how to proxy regular HTTP requests to another backend but it\'s not working for websockets, p

Answer 1

Webpack dev server does not support proxying ws connections yet.

Until then, you can implement proxying manually, by adding additional http-proxy to webpack server:

• Add new dependency to package.json:

  "http-proxy": "^1.11.2"
  

• Proxy websocket connections manually by listening to upgrade events

  // existing webpack-dev-server setup
  // ...
  var server = new WebpackDevServer(...);
  
  proxy = require('http-proxy').createProxyServer();
  server.listeningApp.on('upgrade', function(req, socket) {
    if (req.url.match('/socket_url_to_match')) {
      console.log('proxying ws', req.url);
      proxy.ws(req, socket, {'target': 'ws://localhost:4000/'});
    }
  });
  //start listening
  server.listen(...)   
  

NOTE (after using this for some time)

There is an issue with proxying websockets as socket.io is used by WebpackDevServer to notify browser of code changes. socket.io may conflict with proxying websockets; in my case, connections were being dropped before handshake was returned from my server unless it responded very quickly.

At that point, I just ditched WebpackDevServer and used custom implementation based on react-hot-boilerplate

Answer 2

@Mr. Spice's answer is correct. But it can be further simplified, check http-proxy-middleware, it can be set as following, i.e. just add ws: true and keep other settings as usual.

// proxy middleware options
var options = {
        target: 'http://www.example.org', // target host
        changeOrigin: true,               // needed for virtual hosted sites
        ws: true,                         // proxy websockets
        ...

Answer 3

Version 1.15.0 of the webpack-dev-server supports proxying websocket connections. Add the following to your configuration:

devServer: {
  proxy: {
    '/api': {
       target: 'ws://[address]:[port]',
       ws: true
    },
  },
}