bug#45571: Support stable uids and gids for all accounts

[Leo Prikler]

Hi Danny,
Am Samstag, den 02.01.2021, 16:04 +0100 schrieb Danny Milosavljevic:
> Hi Leo,
> 
> > > Considering the goal of Guix, it's weird that with Guix, one
> > > needs to
> > > store&restore /etc/passwd at all.  It's state, but not very
> > > useful
> > > one.
> > > I mean that's how it is right now--but it's still weird.
> > > With /etc/shadow maybe there's a slightly better case, but note
> > > that
> > > the key
> > > to find stuff in /etc/shadow can't be the uid--the uid isn't even
> > > in
> > > there!  
> > AFAIU yes, it's state, but not one that Guix can simply do away
> > with. 
> 
> It's easily possible to recreate /etc/passwd from scratch if the uids
> are
> always specified in <user-account>s and thus /etc/passwd would not
> need to
> be persistent state anymore.  Right now everything from /etc/passwd
> except
> the uid and the comment is already specified in <user-account>.
> 
> So Guix can indeed simply do away with the persistent state of
> /etc/passwd--that's why I suggested specifying the uids in the first
> place.
> 
> (By now I don't think that's the best way to make UIDs stable, but
> it's
> factually incorrect to assert that Guix can't simply do away with
> that
> persistent state specifically.  It can.)
> 
> > There is not yet a syntax for keeping secrets, which would be
> > needed to
> > fully populate /etc from config.scm.  Perhaps we'll get there some
> > day.
> 
> /etc/passwd does not contain secrets.  Neither does /etc/group.
> 
> And /etc/shadow doesn't contain uids.
> 
> So there is no conflict.
Point taken, it is indeed possibly to do away with one of those files,
but looking at them as a trio (as one ought to imo), I don't think
removing one while keeping the other(s) is the way to go.

Also if you do go that route, you would need a way to specify that your
passwd has hitherto been different to all other Guix installations;
hence forcing you to make system account [GU]IDs configurable once
again.

Regards,
Leo