How do I get the rendered output of a controller's action without visiting the web page?

As part of the deployment process for our rails 2.3 app, I'd like to save static versions of our error pages to the public folder. How do I get the rendered output of a controller's action without visiting the web page? I know it can be done because the functional tests do it - if I say

get :errors, :id => 404

then t开发者_C百科he body is in @response.body. I suppose I could just copy the code out of ActionController::TestCase, but I'm hoping that there's a simpler way to do it.

In the end I did just go into ActionController::TestCase, and this is what I dug out:

def get_content host, path, filename
  request = ActionController::Request.new 'HTTP_HOST' => host,
                                          'REQUEST_URI' => path,
                                          'REQUEST_METHOD' => 'GET',
                                          'rack.input' => '',
                                          'rack.url_scheme' => 'http'

  controller = ActionController::Routing::Routes.recognize(request).new
  response = ActionController::Response.new
  controller.process request, response
  return response.body
end