Do you have example index source from external site?
For example : http://www.cnn.com/ListOfExternalLinks.txt (This contain list of markup files and separated by carriage return ).
Basically, the noflow will grap each of the links in ListOfExternalLinks.txt and use it as the source

I checkout this link
https://github.com/the-grid/noflo-jekyll/blob/master/test/BuildPostPath.coffee