Match requests and serve directories of files stored on the local file system (AutoResponder)

[squizzdev]

Our company is moving from Windows to Debian, and previously us developers were using Fiddler's (AutoResponder) feature to capture browser requests for javascript, css etc... and instead serve local copies of files stored in the same relative structure on our local computers (such as in a git repository). This is very helpful when we need to debug UI issues occurring in web pages and data served from our production websites, since we could load the same html pages and ajax requests from the remote server, but load the js and css files stored on our local machine across any web browsers.

For example, we'd have a rule:
Match: https://www.example.com/static-file-assets/*
Serve: file:///path/to/my/coding/repository/static-file-assets/[matched_relative_path]

So this rule could then match a URL such as:
URL: https://www.example.com/static-file-assets/css/styles.css
Return: file:///path/to/my/coding/repository/static-file-assets/css/styles.css

As well as:
URL: https://www.example.com/static-file-assets/js/core/utils.js
Return: file:///path/to/my/coding/repository/static-file-assets/js/core/utils.js

So I'm wondering whether mitmproxy supports this same AutoResponder capability, such as through an addon or script, where it's able to match a certain URL path, then instead serve files stored locally with the same matched relative path?

Having this one feature will enable us to get rid of Fiddler and transition to mitmproxy.

[mhils]

Thanks for the detailed explanation, this is very helpful! 😃

We've already discussed this in #3948.