[systemd-devel] CoreOS Goal Question: Should we be aiming to be able to boot with an empty /etc?

[Lennart Poettering]

On Mon, 07.01.13 09:13, Colin Walters (walters at verbum.org) wrote:

> 
> On Mon, 2013-01-07 at 11:48 +0000, Colin Guthrie wrote:
> > H
> > I was thinking, is it a general stated aim that we should be able to
> > boot with an empty /etc? 
> 
> Definitely quite useful for my plan:
> 
> https://live.gnome.org/OSTree/MultipleRoots
> 
> > I guess the same should be true of /var too probably (i.e. packages
> > should be able to cope with initing themselves on first use and not rely
> > on doing it at package install).
> 
> Yes:
> 
> http://cgit.freedesktop.org/NetworkManager/NetworkManager/commit/?id=e7add58aad1bb5eca28360c9c7a1a3956261c7df
> http://git.gnome.org/browse/gdm/commit/?id=b18a7464095fa724b8160ebe2388f925558be5da
> ...and others.

BTW, Kay and I were thinking about coming up with a simple scheme that
could pre-initialize a couple of files in /etc and /var that cannot
really sensibly be dropped. For example, UID assignemnts unfortunately
cannot be shipped in packages from the distro, they must happen
dynamically on the local system, due to their limited 32bit namespace
(wouldn't it be awesome to have 128bit IDs like a certain other
OS?). What we were thinking of is that RPMs could ship minimal
"manifest" files that include information about which users need to be
recreated if /etc is dropped and which file owenerships they must
match. After flushing /var and /etc, playing back these manifests should
execute the minimal operations to get pack /etc with passwd/group
initialized and match the UIDs used on the fs and maybe a few other
things.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.