httpPOST.js

var http = require('http');


function httpPOST(options, body, cb) {
    const req = http.request(options, function (res) {
        if (!res)
            return cb(res);
        else if ((res.statusCode / 100 | 0) > 3)
            return cb(res);
        return cb(null, res);
    });
    req.write(body);
    req.end();
}

const body = JSON.stringify({hello: 'world'}),
    opts0 = {
        method: 'POST',
        protocol: 'http:',
        host: 'httpbin.org',
        path: 'post',
        headers: {
            'Content-Type': 'application/json',
            'Content-Length': Buffer.byteLength(body)
        }
    },
    opts1 = {
        method: 'POST',
        protocol: 'http:',
        host: 'httpbin.org',
        path: '/post',
        headers: opts0['headers']
    };

httpPOST(opts0, body, function (error, result) {
    if (error) console.error(error.statusCode, error.statusMessage);
    else console.info(result.statusCode, result.statusMessage);
    httpPOST(opts1, body, function (err, res) {
        if (err) console.error(err.statusCode, err.statusMessage);
        else console.info(res.statusCode, res.statusMessage);
    });
});