Start it directly via
docker run -ti pesto42/alpine33-rpi /bin/sh
or use it as FROM in your Dockerfile as a small basis for own images.
For Raspi I suppose to use hypriot to get docker up and running.
This image also runs on Odroid-C2 [http://odroid.com/dokuwiki/doku.php?id=en:odroid-c2] with Ubuntu 16.04.
see my repository on github for more information: