Basic proxy setup for create-react-app to work with remote backend

setupProxy.js

let proxy = require('http-proxy-middleware');

module.exports = app => {
  let backend = proxy({
    target: process.env.DATAROBOT_ENDPOINT,
    changeOrigin: true,
  });
  let socket = proxy('/socket.io-queue', {
    target: process.env.DATAROBOT_ENDPOINT,
    changeOrigin: true,
    ws: true,
  });
  app.use(socket);
  app.use((req, res, next) => {
    if (req.path.startsWith(process.env.PUBLIC_URL)) {
      next();
    } else {
      backend(req, res, next);
    }
  });
};