Adapter for authlogic to make it function as a Rack middleware. First you‘ll have write your own Rack adapter where you have to set your cookie domain.

    class YourRackAdapter < Authlogic::ControllerAdapters::RackAdapter
      def cookie_domain
        'your_cookie_domain_here.com'
      end
    end

Next you need to set up a rack middleware like this:

    class AuthlogicMiddleware
      def initialize(app)
        @app = app
      end

      def call(env)
        YourRackAdapter.new(env)
        @app.call(env)
      end
    end

And that is all! Now just load this middleware into rack:

    use AuthlogicMiddleware

Authlogic will expect a User and a UserSession object to be present:

    class UserSession < Authlogic::Session::Base
      # Authlogic options go here
    end

    class User < ActiveRecord::Base
      acts_as_authentic
    end