If installing via apt-get, that means creating a debian package that provides lxc-docker-1.6.2 (docker 1.7 broke backwards compatibility in output of docker ps). Otherwise, just patching the [Makefile](https://github.com/progrium/dokku/blob/master/Makefile#L85) to check for bocker (linked to `/usr/local/bin/docker` of course) would suffice.
Though I don't think that is what he is asking for.
Though I don't think that is what he is asking for.