server.js

import path from 'path'
import { Server } from 'http'
import Express from 'express'
import React from 'react'
import { renderToString } from 'react-dom/server'
import { match, RouterContext } from 'react-router'
import routes from './src/routes'
import NotFoundPage from './src/modules/notfound'

// initialize the server and configure support for ejs templates
const app = new Express()
const server = new Server(app)
app.set('view engine', 'ejs')
app.set('views', path.join(__dirname, 'config'))

// define the folder that will be used for static assets
app.use(Express.static(path.join(__dirname, 'dist')))

// universal routing and rendering
app.get('*', (req, res) => {
  match(
    { routes, location: req.url },
    (err, redirectLocation, renderProps) => {

      // in case of error display the error message
      if (err) {
        return res.status(500).send(err.message)
      }

      // in case of redirect propagate the redirect to the browser
      if (redirectLocation) {
        return res.redirect(302, redirectLocation.pathname + redirectLocation.search)
      }

      // generate the React markup for the current route
      let markup;
      if (renderProps) {
        // if the current route matched we have renderProps
        markup = renderToString(<RouterContext {...renderProps}/>)
      } else {
        // otherwise we can render a 404 page
        markup = renderToString(<NotFoundPage/>)
        res.status(404);
      }

      // render the index template with the embedded React markup
      return res.render('index', { markup })
    }
  );
});

// start the server
const port = process.env.PORT || 3000
const env = process.env.NODE_ENV || 'production'
server.listen(port, err => {
  if (err) {
    return console.error(err)
  }
  console.info(`Server running on http://localhost:${port} [${env}]`)
});