Intercept traffic in local mode, then forward to upstream proxy

[lawrence-forooghian]

I would like to implement the following behaviour:

1. Use mitmproxy’s local mode in order to transparently intercept all traffic from a given process and to handle TLS termination, then
2. Instruct this instance of mitmproxy to forward all intercepted traffic to another proxy server.

As an example, I naïvely thought that mitmproxy --mode local:curl --mode upstream:http://localhost:8081 might allow me to capture all curl traffic and forward it to a proxy running at http://localhost:8081. However, when I run a proxy at http://localhost:8081 using mitmproxy --listen-port 8081, this second instance of mitmproxy doesn’t display any traffic, suggesting that the first instance is not forwarding traffic.

Is there something I’m misunderstanding here?

[mhils]

mitmproxy --mode local:curl --mode upstream:http://localhost:8081

This commands starts two proxy modes: First, proxy all local cURL traffic. Second, spawn an HTTP proxy on port 8080 that will forward all traffic to another HTTP proxy upstream at localhost:8081. Proxy modes are not "interconnected".
There currently is no (easy) way to use an upstream proxy with local redirect mode.

[lawrence-forooghian]

Got it, thank you!

There currently is no (easy) way to use an upstream proxy with local redirect mode.

I’m assuming that means "even if you write an add-on"?