node server for fastboot with geoip

nginx.conf

server {
    listen 80;

    server_name foo.foo;

    location / {
        proxy_pass http://localhost:3000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_cache_bypass $http_upgrade;
    }
  
    location ~* "^/assets/.*-([a-z0-9]{32})\.(?:css|js|gif|png|jpe?g)$" {
        root /foo/dir;
        expires max;
        add_header Cache-Control public;
        access_log off;
        try_files $uri =404;
    }
}

server.js

'use strict';
const geoip = require('geoip-lite');
const FSNotifier = require('fastboot-fs-notifier');
const FastBootAppServer = require('fastboot-app-server');

let geo = null;

const getGeoIP = function(req, res, next) {
  const ip = req.header('X-Real-IP');
  if (!geo) {
    geo = geoip.lookup(ip);
  }
  if (geo) {
    req.headers['X-Geo-Country'] = geo.country;
    req.headers['X-Geo-Region'] = geo.region;
    req.headers['X-Geo-City'] = geo.city;
    req.headers['X-Geo-Lat'] = geo.ll[0].toString();
    req.headers['X-Geo-Lng'] = geo.ll[1].toString();
  }
  next();
};

const notifier = new FSNotifier({
  targetDir: 'app'
});

const server = new FastBootAppServer({
  beforeMiddleware(app) { app.use(getGeoIP); },
  distPath: 'app',
  notifier: notifier,
  gzip: true,
  workerCount: 2
});

server.start();