munging_http_proxy lets you easily modify or intercept HTTP requests passing through the proxy. All you need to do is write a Python function that takes a WebOb Request, and either mutates it and returns None (request will be passed on, and the response from the server relayed to the client), or directly returns a suitable WebOb Response (server will never be contacted).

Note that some of the fields of a WebOb Request are read-only properties. For example, you cannot set req.path, you'll have to set req.path_info and/or req.script_name.

munging_http_proxy also contains an interactive mode, where every request is explorable in an interactive Python session. In this mode, use req to access the Request, and set resp if you wish to directly return a specific Response. For convenience, any other variables you set are remembered between the requests.

To get started, type:

./bootstrap

And for interactive mode, type:

./virtualenv/bin/interactive-http-proxy

Now you can make requests using the HTTP proxy. For example (in another window):

http_proxy=http://localhost:8088/ wget -nv -O- 'http://example.com/'