Ember-CLI copy resources from URL to public-folder (triggered by Ember)

My backend-server (Sails) generates a sitemap dynamically which is made available via http://ift.tt/1L7Ejmn. I would like to copy this (and a few RSS-feeds with the same procedure) into the public-folder everytime I trigger it somehow from my Ember-app.

How can I achieve this?

I've seen the http://ift.tt/1MuEv2z but I don't know whether that can copy from URLs and also I don't know how to trigger it from my App.