Docker Host Image: Requirements?

[Sandro "red" Mathys]

Heads-up: I've claimed ownership over the Docker Host Image Change:
https://fedoraproject.org/wiki/Cloud_Changelist#Change:_Docker_Host_Image

Now, while I'm very interested in Docker, I've never seriously /
productively used it nor ever used it to actually implement PaaS on
top of IaaS. Sp, i'm pretty sure some people out there have more
experience with Docker than I do and therefore I'd value your input.
To me it currently seems there's only a very few, very small changes
to add to the cloud base image, i.e.:

1) add docker-io to %packages
2) systemctl enable docker.service

Since we try to compete with CoreOS, do we also want to add etcd out
of the box? That'd double the necessary changes, though! ;)

3) add etcd to %packages
4) systemctl enable etcd.service

What else would you expect from the Docker Host Image? This is way too
easy, so kindly tell me what obvious things I'm clearly missing. Apart
from "you need to actually make sure an image is built and working"...
:)

Thanks,
Sandro