Dynamically Updated Node.js HTTP Proxy Server (UI Edge Server)

proxy-server.js

const http = require('http'),
      httpProxy = require('http-proxy'),
      HttpProxyRules = require('http-proxy-rules');

let proxyConfiguration = {
  rules: {
    '.*/test': 'http://localhost:8080/cool', // Rule (1)
    '.*/test2/': 'http://localhost:8080/cool2/' // Rule (2)
  },
  default: 'http://localhost:8080' // default target
}
// Set up proxy rules instance
let proxyRules = new HttpProxyRules(proxyConfiguration);

// A registry server alongside this module can call this function to
// update the rules as microapps appear, disappear or change
module.exports.updateProxyConfiguration = function (newProxyConfiguration) {
  proxyConfiguration = newProxyConfiguration;
  proxyRules = new HttpProxyRules(proxyConfiguration);
};

// Create reverse proxy instance
const proxy = httpProxy.createProxy();

// Create http server that leverages reverse proxy instance
// and proxy rules to proxy requests to different targets
http.createServer(function(req, res) {

  // a match method is exposed on the proxy rules instance
  // to test a request to see if it matches against one of the specified rules
  let target = proxyRules.match(req);
  if (target) {
    return proxy.web(req, res, {
      target: target
    });
  }

  res.writeHead(500, { 'Content-Type': 'text/plain' });
  res.end('The request url and path did not match any of the listed rules!');
}).listen(6010, () => console.info('Listening'));

registry-server.js

const http = require('http'),
      ProxyServer = require('./proxy-server');

// Create http server that microapps talk to register themselves
// for routes in the edge server
http.createServer(function(req, res) {
  ProxyServer.updateProxyConfiguration(req.body.proxyConfiguration)

  res.writeHead(200, { 'Content-Type': 'application/json' });
  res.end(JSON.stringify({ ok : true }));
}).listen(6020, () => console.info('Listening'));