Api gateway nodejs multiport http https #nodejs

gateway.js

const express = require('express');
const proxy = require('http-proxy-middleware');
const fs = require("fs");
const { createServer } = require('https');

const certOptions = {
  key: fs.readFileSync('/etc/letsencrypt/live/s1.example.com/privkey.pem'),
  cert: fs.readFileSync('/etc/letsencrypt/live/s1.example.com/fullchain.pem'),
};

const mainSystem = express();

// support https
createServer(certOptions, mainSystem).listen(443, (err) => {
  if (err) throw err;
  console.log('> Ready on https://example.com');
});

// redirect to https
mainSystem.use(function(req, res, next) {
  if (req.secure) {
    // request was via https, so do no special handling
    next();
  }
  else {
    // request was via http, so redirect to https
    // res.redirect('https://' + req.headers.host + req.url); 
  }
});

mainSystem.use('*', (req, res, next) => {
  switch (req.headers.host) {
    case 'example.com': // like nextjs
      proxy({ target: 'http://localhost:portweb', changeOrigin: true })(req, res, next);
      break;
    case 's1.example.com': // backend microservice 01, with websocket
      proxy({ target: 'http://localhost:port01', changeOrigin: true, ws: true })(req, res, next);
      break;
    case 's2.dev.houselink.info': // backend microservice 01, with websocket
      proxy({ target: 'http://localhost:port02', changeOrigin: true, ws: true })(req, res, next);
      break;
    default:
      proxy({ target: 'http://localhost:portweb', changeOrigin: true })(req, res, next);
  }
});

mainSystem.listen(80);