server.js

// This file doesn't go through babel or webpack transformation.
// Make sure the syntax and sources this file requires are compatible with the current node version you are running
// See https://github.com/zeit/next.js/issues/1245 for discussions on Universal Webpack or universal Babel
const { createServer } = require('http');
const { parse } = require('url');
const next = require('next');

const dev = process.env.NODE_ENV !== 'production';
const app = next({ dir: './src', dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  createServer((req, res) => {
    // Be sure to pass `true` as the second argument to `url.parse`.
    // This tells it to parse the query portion of the URL.
    const parsedUrl = parse(req.url, true);
    const { pathname, query } = parsedUrl;

    if (pathname === '/health') { // health check
      res.end('ok')
    } else {
      handle(req, res, parsedUrl);
    }
  }).listen(3000, err => {
    if (err) throw err;
    console.log('> Ready on http://localhost:3000');
  });
});