server.js

const path = require('path');
const express = require('express');
const cluster = require('cluster');

const app = express(); 

// middleware to serve gzipped js file.
// app.get('*.js', function (req, res, next) {
//   req.url = req.url + '.gz';
//   res.set('Content-Encoding', 'gzip');
//   next();
// });

app.use(express.static(path.join(__dirname, 'dist')));

app.get('*', function(req, res) {
  res.sendFile(path.join(__dirname, 'dist', 'index.html'));
});

if(cluster.isMaster){
	const cores = require('os').cpus().length;

	console.log('Master cluster setting up', cores, 'workers...');
	for(let i = 0; i < cores; i++) cluster.fork();

	cluster.on('online', (worker) => console.log('Worker', worker.process.pid, 'is online'));
	cluster.on('exit', (worker, code, signal) => {
		console.log('Worker', worker.process.pid, 'died with code:', code, 'and signal:', signal);
		console.log('Starting a new worker');
		cluster.fork();
	});
}else {
	app.listen(process.env.PORT || 8080, function(err) {
	  if (err) {
	    return console.error(err);
	  }

	  console.log('Listening at http://localhost:' + (process.env.PORT || 8080));
	});
}