Node JS script as static server and proxy server

fe-server.js

var static = require('node-static');
var rootRequest = require('request');
var fs = require('fs');
var path = require('path');

var buildInProgress = false;

module.exports = function(options) {
    console.log('options', options);
    var baseUrl = 'https://dev.azurewebsites.net';
    let origin = 'http://localhost:4200';
    if (options.endpoint && options.endpoint.toLowerCase() === 'uat'.toLowerCase()) {
        baseUrl = 'http://uat.azurewebsites.net';
        origin = 'https://uat.azurewebsites.net';
    }

    var requestOptions = {
        url: '',
        headers: {
            'Content-Type': 'application/json',
            'Origin': origin
        },
        method: 'POST',
        json: true,
        body: {}
    };

    fePort = options.fePort;
    folder = options.folder || 'master';
    var server = require('http').createServer((request, response) => {
        var body = [];
        if (request.url.indexOf('api') >= 0) {
            request.on('data', function(chunk) {
                body.push(chunk);
            });
        }
        request.addListener('end', function() {
            if (request.method === 'OPTIONS') {
                response.setHeader('Access-Control-Allow-Origin', '*');
                response.setHeader('Access-Control-Allow-Headers', 'Content-Type, x-api-key');
                response.writeHead(200, {
                    'Content-Type': 'application/json'
                });
                response.end();

            } else if (request.url.indexOf('api') >= 0) {
                body = Buffer.concat(body).toString();
                try {
                    body = JSON.parse(body);
                } catch (e) {}
                requestOptions.url = baseUrl + request.url;
                requestOptions.body = body;
                requestOptions.method = request.method;
                if (request.headers['authorization']) {
                    requestOptions.headers['authorization'] = request.headers['authorization'];
                }
                if (request.headers['Authorization']) {
                    requestOptions.headers['Authorization'] = request.headers['Authorization'];
                }

                if (request.headers['X-API-Key']) {
                    requestOptions.headers['X-API-Key'] = request.headers['X-API-Key'];
                }

                if (request.headers['X-API-Key'.toLowerCase()]) {
                    requestOptions.headers['X-API-Key'] = request.headers['X-API-Key'.toLowerCase()];
                }
                console.log(`[LOG ${requestOptions.method} ] : ${requestOptions.url}`);
                console.log(`[Request Details] : ` + JSON.stringify(requestOptions.headers));

                rootRequest(requestOptions, (err, resp, rootBody) => {
                    response.setHeader('Access-Control-Allow-Origin', '*');
                    response.setHeader('Access-Control-Expose-Headers', 'Authorization, Location, authorization');
                    if (resp.headers['authorization']) {
                        response.setHeader('authorization', resp.headers['authorization']);
                    }
                    if (resp.headers['Authorization']) {
                        response.setHeader('Authorization', resp.headers['Authorization']);
                    }

                    response.writeHead(resp.statusCode, {
                        'Content-Type': 'application/json'
                    });
                    if (rootBody) {
                        response.write(JSON.stringify(rootBody))
                    }
                    response.end();
                });
            } else {
                var file = new static.Server('./' + folder, { headers: { gzip: true } });
                if (request.url.indexOf('.gz') >= 0) {
                    console.log('serving from gzip', request.url);
                    var headers = { 'Content-Encoding': 'gzip' };
                    if (request.url.indexOf('.css') >= 0) {
                        headers['Content-Type'] = 'text/css';
                    }
                    file.serveFile('/' + request.url, 200, headers, request, response);
                } else {
                    file.serve(request, response, function(err, res) {
                        if (err && (err.status === 404) && request.url.indexOf('.html') < 0) {
                            fs.exists(path.join(__dirname, folder, 'index.html'), (exists) => {
                                if (exists) {
                                    file.serveFile('/index.html', 200, {}, request, response);
                                } else {
                                    response.writeHead(200, { 'content-type': 'text/html' });
                                    response.end('Build in progress.......');
                                }
                            });
                        } else {
                            response.writeHead(200, { 'content-type': 'text/html' });
                            response.end('Resource Not Found');
                        }
                    });
                }
            }
        }).resume();
    }).listen(fePort, () => {
        console.log('Server Listining on ' + fePort);
    })
};

index.js

let port = 80,
    folder = 'dist',
    endpoint = "dev";
if (process.argv) {
    process.argv.forEach((p) => {
        if (p.indexOf('--port=') >= 0) {
            port = parseInt(p.split('=')[1]);
        }
    });
    process.argv.forEach((p) => {
        if (p.indexOf('--folder=') >= 0) {
            folder = p.split('=')[1];
        }
    });
    process.argv.forEach((p) => {
        if (p.indexOf('--endpoint=') >= 0) {
            endpoint = p.split('=')[1];
        }
    });
}
require('./fe-server')({ fePort: port, folder, endpoint: endpoint });


// Run below command in terminal
// node index.js --port=4200 --endpoint=dev