server.js

"use strict";

var http = require("http");
var wkhtmltopdf = require('wkhtmltopdf');
var qs = require('querystring');

http.createServer(function (request, response) {
    if (request.method === 'POST') {
        var body = '';
        request.on('data', function (data) {
            body += data;
        });

        request.on('end', function () {
            var post = qs.parse(body),
                html = post.html;
            if (html !== undefined) {
                response.writeHead(200, {
                    'Content-Type': 'application/pdf',
                });
                delete post.html;
                wkhtmltopdf(html, post, function (code) {
                    if (code !== null) {
                        response.writeHead(500, "Internal Server Error", {'Content-Type': 'text/html'});
                        response.end();
                        console.log(code);
                    }
                }).pipe(response);
            } else {
                response.writeHead(400, "Bad Request", {'Content-Type': 'text/html'});
                response.end();
            }
        });
    } else {
        response.writeHead(200, "OK", {'Content-Type': 'text/html'});
        response.end();
    }
}).listen(5001);

console.log("Server is running at http://127.0.0.1:5001");