I use this myself to host my website. I've forked it and added buildpacks for Jekyll and Octopress (one of the recent commits broke Octopress) for anyone who's interested and although I haven't cleaned it up enough to submit a pull request, it works perfectly. May take a look at sending one over the holidays

Octopress bare repo: https://github.com/rodeva/octopress-dokku-bare

Dokku fork for Jekyll and Octopress: https://github.com/rodeva/dokku