This Rack middleware is very simply and only does one thing: fixes the PATH_INFO environment variable. Apache and mod_python messes up the path info, by stripping the first path segment from it and setting the SCRIPT_NAME to that segment. This isn't wrong behaviour, but Rack applications expect the segement there when matching up mapped routes.

To install via gems:

gem install rack-pathinfo-fix

Or, if you are using the preferred method of Bundler, in your Gemfile:

gem 'rack-pathinfo-fix'

In your config.ru

require 'rack_pathinfo_fix' # If you're not using Bundler.
require 'app.rb'            # whatever your app file is.

use RackPathInfoFix

run App

This also fixes things if you have to map other handlers:

use RackPathInfoFix

map '/assets' do
  run AssetsHandler
end

map '/'
  run App
end

This README is longer than the actual middleware class. :)