server.js

var express = require('express');
var path = require('path');
var httpProxy = require('http-proxy');
var http = require('http');
var proxy = httpProxy.createProxyServer({
  changeOrigin: true,
  ws: true
}); 
var falcorExpress = require('falcor-express');
var Router = require('falcor-router');
var app = express();
var isProduction = process.env.NODE_ENV === 'production';
var port = isProduction ? process.env.PORT : 3000;
var publicPath = path.resolve(__dirname, 'public');

app.use(express.static(publicPath));

app.use('/model.json', falcorExpress.dataSourceRoute(function (req, res) {
  // create a Virtual JSON resource with single key ("greeting")
  return new Router([
    {
      // match a request for the key "greeting"    
      route: "greeting",
      // respond with a PathValue with the value of "Hello World."
      get: function() {
        return {path:["greeting"], value: "Hello World"};
      }
    }
  ]);
}));

app.all('/db/*', function (req, res) {
  proxy.web(req, res, {
    target: 'https://glowing-carpet-4534.firebaseio.com/'
  });
});

if (!isProduction) {

  var bundle = require('./server/bundle.js');
  bundle();
  app.all('/build/*', function (req, res) {
    proxy.web(req, res, {
        target: 'http://127.0.0.1:3001'
    });
  });
  app.all('/socket.io*', function (req, res) {
    proxy.web(req, res, {
      target: 'http://127.0.0.1:3001'
    });
  });


  proxy.on('error', function(e) {
    // Just catch it
  });

  // We need to use basic HTTP service to proxy
  // websocket requests from webpack
  var server = http.createServer(app);

  server.on('upgrade', function (req, socket, head) {
    proxy.ws(req, socket, head);
  });

  server.listen(port, function () {
    console.log('Server running on port ' + port);
  }); 

} else {

  // And run the server
  app.listen(port, function () {
    console.log('Server running on port ' + port);
  });

}