Antw: [EXT] all numeric usernames not allowed in systemd (version 245 onward)

["Ulrich Windl" <Ulrich.Windl@xxxxxxxxxxxxxxxxxxxx>]

>>> Nikhil Kshirsagar <nkshirsagar@xxxxxxxxx> schrieb am 07.04.2022 um 13:07 in
Nachricht
<CAC6jXv3Ta57s3ACJjE-w+UxgW8NOhP3g52j4OJ02U0mqSfOWrQ@xxxxxxxxxxxxxx>:
> Hello,
> 
> I gather from the discussion on
> https://github.com/systemd/systemd/issues/15141 that all numeric usernames
> would no longer be supported on servers running systemd version 245 onward.
> This was also reiterated by Frantisek and Lennart (thank you for your email
> responses and for redirecting me to this mailing list.)

AFAIK there never were numeric user names in UNIX: If a user specification ws numeric, it was the UID of a user, not the name.
(VAX had different concepts however)
I mean: If you wanted to shoot yourself in the foot you would use numeric user names like this:

(pwasswd)
123:333:...
333:123:...

chown 333 file...

> 
> While I completely understand the motivation to do this, my concern is that
> this change will break logins for users on a lot of servers that upgrade to
> the new systemd.

Can you give examples of numeric user names being used?

> 
> Is there any chance systemd could support a configuration option in the
> future to get the earlier "all numeric" user logins to work? With an
> understanding that it would be at the users own risk?
> 
> Are there any pam_systemd configuration options under consideration that
> might help anyone looking for such functionality? Or is the only option
> "not to upgrade" for someone interested in preserving their all numeric
> usernames?
> 
> Regards,
> Nikhil.