Re: Can't update /etc/sysconfig/docker-storage-setup from custom repo

[Colin Walters <walters verbum org>]

On Thu, Mar 1, 2018, at 2:16 PM, Dan Nicholson wrote:

> I don't know exactly how container-storage-setup works, but I'm
> guessing it only accepts configuration via /etc/sysconfig. In that
> case, you'll probably have to write your own tool that merges changes
> from /usr/etc/sysconfig/docker-storage-setup to
> /etc/sysconfig/docker-storage-setup at boot time.

One issue specifically with this software is that it modifies a file in
/etc on first-run.

> I realize this makes you a sad panda (it often makes me sad and lose
> sleep that our users aren't receiving important changes because they
> happen to have edited a file in /etc),

But IMO a very cool property of the ostree model is `ostree admin config-diff`.
So you can always trivially restore the defaults.  In your case are you concerned
about this for *technical* users or cases like container-storage-setup where
the software changes /etc and you want to be able to reset it later?

> What I've often thought about is providing /etc merge hooks in ostree
> that run during the deployment. It would be pretty complex, though.
> ostree already does something very similar for selinux relabeling and
> it is not trivial.

Mmm...I don't think it would be too hard to implement an arbitrary
hook so that you could even do Debconf-style interactions if you
wanted to.  It'd avoid this happening at least:
https://twitter.com/jamesdotcuff/status/970362014513147905
as it'd still be transactional (if implemented well) and you'd just be prompted again
next time you tried to update.