custom-http-agent-with-dns-resolve.js

const dns = require('dns');
const http = require('http');
const https = require('https');
const tls = require('tls');
const net = require('net');
const request = require('request');

const httpAgent = new http.Agent();
const httpsAgent = new https.Agent();

const createConnection = ({ isHttps = false } = {}) => {
    const connect = isHttps ? tls.connect : net.connect;
    return function(args, cb) {
        return connect({
            port : args.port,
            host : args.host,
            lookup : function(hostname, args, cb) {
                dns.resolve(hostname, function(err, ips) {
                    if (err) { return cb(err); }

                    return cb(null, ips[0], 4);
                });
            }
        }, cb);
    }
};

httpAgent.createConnection = createConnection();
httpsAgent.createConnection = createConnection({isHttps: true});

function getRequest(reqUrl) {
    request({
        method: 'get',
        url: reqUrl,
        agent: httpsAgent
    }, (err, res) => {
        if (err) throw err;
        console.log(res.body);
    })
}

getRequest('https://example.com');