express javascript node.js proxy

Edit POST parameters prior to forwarding to a proxy target and sending response back to client

I have a node/express proxy setup using http-proxy-middleware to route requests to a java-tomcat web service (proxy target).

I need to inject POST form data into the request rawbody with a context-type of “application/x-www-form-urlencoded” prior to forwarding the request to the proxy target. The proxy response will need to have the same post parameters removed prior to sending the response to the client.

I have used a number of different proxies include http-proxy, http-proxy-middleware, node-proxy, and express-proxy but none of these modules appear to have a solution available that allows for POST parameter manipulation

This question was originally posted on

'use strict';
var express = require('express');
var router = express.Router();
//var request = require("request");
var proxy_filter = function (path, req) {
return path.match('^/report') && ( req.method === 'GET' || req.method === 'POST' );
var proxy_options = {
target: 'http://localhost:8080',
logLevel: 'debug',
onError(err, req, res) {
res.writeHead(500, {
'Content-Type': 'text/plain'
res.end('Something went wrong. And we are reporting a custom error message.' + err);
onProxyRes(proxyRes, req, res) {
//proxyRes.headers['x-added'] = 'foobar'; // add new header to response
//delete proxyRes.headers['x-removed']; // remove header from response
onProxyReq(proxyReq, req, res) {
if ( req.method == "POST" && req.body ) {
proxyReq.write( encodeURIComponent( JSON.stringify( req.body ) ) );
// Proxy configuration
var proxy = require( 'http-proxy-middleware' )( proxy_filter, proxy_options );
/* GET home page. */
router.get('/', function(req, res, next) {
res.render('index', { title: 'Node.js Express Proxy Test' });
router.all('/report/*', function( req, res, next ) {
//req.body.jdbc_agency = 'jdbc:postgresql://pg_dev:5432/agency0329';
//console.log('proxy body:',req.body);
proxy( req, res, next );
} );
module.exports = router;

Any suggestions are greatly appreciated.