foo_bar_middleware.rb

# In /lib/foo_bar_middleware.rb

class FooBarMiddleware
  
  def initialize(app, options={})
    @app = app
    # options will be {:foo => :bar} if you look lower down, you can use this in other methods etc
    @options = options
  end
  
  def call(env)
    request = ::Rack::Request.new(env)
    @cookies = request.cookies
    @app.call(env)
  end
  
  
end

# In environment.rb:
config.middleware.insert_before(ActionController::Session::CookieStore, 'FooBarMiddleware', {:foo => :bar})