These instructions assume you are running an x86-64 Ascii build. They were tested in December of 2018 and are 
likely to change.

This was tested on a KVM VPS.

Follow the instructions here:

https://docs.docker.com/install/linux/docker-ce/debian/

On the step for adding the docker repo to apt.sources you will use
deb [arch=amd64] https://download.docker.com/linux/debian stretch stable

instead of
 sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/debian \
   $(lsb_release -cs) \
   stable"

which of course adds stretch compatible repos.

At this point docker is installed, and the binary in /usr/bin/ is available but docker
server isn't running (for me). 

the command # dockerd
will run the docker daemon, but we want an init script.

Note that this post (link: https://paddy-hack.gitlab.io/posts/sandwiching-docker-with-devuan/) mentions that 
aufs is not supported in the Linux 4.9 image from Jessie-backports.
While Ascii uses 4.9, AUFS apparently works, no problem. No need to change to BTRFS in ASCII.

However, there is a problem.
The sysvinit init scripts have been very recently removed from docker-ce (link: 
https://github.com/docker/for-linux/issues/482)

If you git clone github.com/moby/moby
and navigate to contrib/init/sysvinit-debian/
you will find an init script there that can be used...
As well as a file for /etc/default



And after adding this init file, docker will load the hello-world file.

That's it!