server.js

import verCompare from 'node-version-compare';
import express from 'express';
import versions from './data/version';

const app = express();
app.use('/firmware', express.static('firmware'));
app.get('/hello', (req, res) => res.send('World!'));
app.get('/', (req, res) => {
  const [reqMac, reqDevice, reqVersion] = [
    'X-ESP8266-MAC',
    'X-ESP8266-DEVICE',
    'X-ESP8266-VERSION',
  ].map(v => req.get(v.toLowerCase()));

  console.log('[req]', new Date(), reqMac, reqDevice, reqVersion);

  if (reqMac && reqDevice && reqVersion) {
    const [resp = {}] = versions.filter(v => {
      const { mac, device, version, min, max } = v.origin;

      if (device !== reqDevice) return false;
      console.log({ mac, reqMac });
      if (mac !== '*' && mac !== reqMac) return false;

      const minVersionCompare = verCompare(min, reqVersion);
      const maxVersionCompare = verCompare(reqVersion, max);

      if (min !== '*' && minVersionCompare === 1) return false;

      if (max !== '*' && maxVersionCompare > 0) return false;
      return true;
    });
    const { target = {} } = resp;
    return res.json(target);
  }
  res.json({});
});

app.listen(3000, () => console.log('Update server listening on port 3000!'));