How to query a request at Nodejs Proxy Server?

Question

I have a Nodejs Proxy server like this:

`var http = require('http'),
httpProxy = require('http-proxy');

var proxy = httpProxy.createProxyServer({});

proxy.on('proxyReq', function(proxyReq, req, res, options) {
  proxyReq.setHeader('X-Special-Proxy-Header', 'foobar');
});

var server = http.createServer(function(req, res) {
    console.log(req.body);
  proxy.web(req, res, {
    target: 'http://localhost:3000'
  });
 });

console.log("listening on port 9000")
server.listen(9000);`

What i want is get the req.body at the proxy server when i post a request to the Origin server, go through the proxy server. I used "console.log(req.body);" at both proxy server and the origin server. I get the body object {"id": "user003"} at origin server, but undefined at the proxy server. So how can i get the req.body at proxy server?

Answer 1

I suspect the problem here is that you don't have a body parser on your proxy server, but do have one on your origin.

req.body itself isn't set by node. Instead, you have to handle events emitted by the req stream:

let body = '';
req.on('data', (data) => {
    // data is a buffer so need toString()
    body += data.toString();
});

req.on('end', () => {
    // at this point you'll have the full body
    console.log(body);
});

You can make this easier with a body parser (eg https://www.npmjs.com/package/body-parser ) but since you're running a proxy server, you probably don't want to parse the entire req stream before forwarding onto your origin. So I'd maybe stick with handling the events.