moll
commented
6 years ago Hey,
As Mitm is implemented right now, it wouldn't indeed be possible to have the request proceed transparently. Once a TCP connection has been permitted to reach the connection stage (i.e. not bypass()ed in the connect handler), data in the request body buffers will have been transferred to ones Mitm created. The request stage is even further along the process --- by that time the request will not only have been read from the "virtual wire", it'll have been parsed by an HTTP server.
Even if Mitm did handle duplicating TCP streams for both the external and internal paths, it'd be unclear if it could support request-level snooping --- while Node/Mitm could perhaps parse particular bytes to an HTTP request, the external server might fail somewhere in the middle. Or vice-versa.
Having said that, Mitm does mimic a full TCP or HTTP server internally. If you'd like to both audit requests and send them forward, you should be able to do that just like you'd write a real proxy server. I haven't done it myself, but it'd look something like this:
var Http = require("http")
mitm.on("connect", function(socket, opts) {
if (opts.proxying) socket.bypass()
})
mitm.on("request", function(req, res) {
// log the request
var proxied = Http.request({host: req.host, path: req.path, proxying: true})
req.body.pipe(proxied)
req.body.on("end", proxied.end.bind(proxied))
proxied.pipe(res)
proxied.on("end", res.end.bind(res))
})Or something like that. Haven't played with streams in a while, so my request piping code is probably off. Maybe there's even an existing module that does proxying for you given an incoming HTTP request. Naturally supporting both HTTPS and HTTP makes it more complicated as Mitm currently strips HTTPS out entirely.
I do think the route Mitm went with --- faking a server --- is actually more flexible. You could do all kinds of rewriting in that request handler (or connection handler if you want to go a level lower) without Mitm forcing you to use its methods for recording request bodies. Let me know that works out for you.
papandreou
alexjeffburke
ianwsperber
Hi! It's unclear to me from the docs, but after intercepting a request is it possible to allow the request to resume and continue to its destination, so that we may intercept the response? I would like to intercept requests to record the request information, then record the response after. However I have not found a mechanism to accomplish this.
Ideally I would be able to write something to the effect of:
But this will just cause the request to hang, since I do not send back a response. I would like to be able to bypass the mocking here as one can with connections.
I've been reading over the source code and have begun to understand how mitm manages to intercept requests. If you are able to offer any pointers on why we cannot intercept the response today and how one could accomplish it, I would greatly appreciate it :) Ideally I would be able to create a PR to add this functionality.