Proxying POST with Node.js and modifying headers

Question

My local development script uses proxying to get around CORS (among other things). I first go get some false cookies which allow me to skip authentication in my app while developing. The callback to spoofCookies then set up my static proxy - which delivers all my local static content, and then sets up a proxy for all calls routed to /microsvc. I take that call, inject my spoofed cookies, and forward it to the same path on a remote host.

This script works great for GET but I am stuck for how to write the POST section. The req never shows the POST form I have sent through my proxy and so I must be doing something really wrong.

Thanks for your time

    /*jslint node:true white:true nomen:true es5:true*/

'use strict';

var PORT_HTTP = process.env.PORT || 4400;
var localAddress =  "http://localhost:" + PORT_HTTP;

var apiAddress = {      label:      "On-site Ethernet Plug",
                        protocol:   "http://",
                        port:       80,
                        host :      "10.17.100.11",
                        microsvc:   "/microsvc",
                        auth:       "/login.form"
                 };

var https = require('https');
var path = require('path');
var express = require('express');
var app = express();
var spoofCookie = require('./utils/spoof-cookies');
var cookies = [];

var proxy = function(myPath, searchOptions, req, res, cookies) {
    var options = {
        hostname: apiAddress.host,
        port: apiAddress.port,
        path: apiAddress.microsvc + searchOptions,
        rejectUnauthorized: false
    };

    if(cookies.length){
        options.headers = {
            "Cookie":cookies[0]
        };
    }

    try {
        console.log('FROM: ' + localAddress + myPath + searchOptions + '\n' +
                    '↳ TO: ' + apiAddress.protocol + apiAddress.host + apiAddress.microsvc + searchOptions);

        options.method = req.method;

        if(options.method == 'POST' || options.method == 'PUT') {

            // HELP
            // form data never appears in output
            console.log(req);

        } else {
            var r = https.request(options, function(resX) {
                resX.setEncoding('utf8');
                var responseData = '';
                resX.on('data', function(chunk) {
                    responseData += chunk;
                });
                resX.on('end', function() {
                    res.send(JSON.parse(responseData));
                });
            });

            r.on('error', function(e) {
                if (e.code == "ENOTFOUND") {
                    console.error("File not found on remote");
                } else {
                    console.error('ff ' + e);
                }
            });
        }

        req.pipe(r).pipe(res);

    } catch (e) {
        console.error(e);
    }
};

// START - first get spoofed cookies
spoofCookie.getCookies(apiAddress, function(cookies) { 

    // set up server
    var httpServer = http.createServer(app);
    httpServer.listen(PORT_HTTP);

    // microservice proxy
    app.use('/microsvc', function (req, res) {
        proxy('/microsvc', req.url, req, res, cookies);
    });

    console.log("HTTP server started: " + localAddress);

});


// static server runs anything that isn't set up for proxy
app.use(express.static(path.resolve(path.join(__dirname, "..", "app"))));

Answer 1

Express is not parsing request body by default.

req.body contains key-value pairs of data submitted in the request body. By default, it is undefined , and is populated when you use body-parsing middleware such as body-parser and multer .

So, the setup with body-parser would look like so.

First, attach middleware somewhere before declaring routes:

var bodyParser = require('body-parser');

// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false }));

// parse application/json
app.use(bodyParser.json());

// microservice proxy
app.use('/microsvc', function (req, res) {
    proxy('/microsvc', req.url, req, res, cookies);
});

Then, access request content in request.body :

if(options.method == 'POST' || options.method == 'PUT') {
    console.log(req.body);
}