after some more thought:
* If app moves to another location, user has to remember to move all this config
* It's not really associated with an app. It's to do with the domain info
* We can put some hints in the UI if app is missing.
part of #703
We removed httpPort with the assumption that docker allocated IPs
and kept them as long as the container is around. This turned out
to be not true because the IP changes on even container restart.
So we now allocate IPs statically. The iprange makes sure we don't
overlap with addons and other CI app or JupyterHub apps.
https://github.com/moby/moby/issues/6743https://github.com/moby/moby/pull/19001