From: Mark H Weaver <mhw@netris.org>
To: "Maxime Devos" <maximedevos@telenet.be>,
"Ludovic Courtès" <ludo@gnu.org>
Cc: Brendan Tildesley <btild@mailbox.org>, 36508@debbugs.gnu.org
Subject: bug#36508: GDM files have incorrect owner after temporarily removing service
Date: Sat, 17 Apr 2021 12:28:10 -0400 [thread overview]
Message-ID: <878s5g98p6.fsf@netris.org> (raw)
In-Reply-To: <38fd9bfdc71c689df1606a0b00d632e423c5defa.camel@telenet.be>
Hi Maxime,
Maxime Devos <maximedevos@telenet.be> writes:
> On Thu, 2021-04-15 at 14:58 -0400, Mark H Weaver wrote:
>> Maintain historical mappings from user/group names to UIDs/GIDs, perhaps
>> in some file in /etc, where entries are added but *never* automatically
>> removed. When allocating UIDs/GIDs, we would avoid any UIDs/GIDs in the
>> range of those mappings.
>
> This seems rather convoluted to me. Why not reuse /etc/passwd and /etc/groups?
> My suggestion:
>
> 1. *never* automatically delete users/groups from /etc/passwd, /etc/groups
> (I thought that was how Guix already worked ...)
> 2. as users and groups appearing in /etc/passwd and /etc/groups, but not
> in the operating system configuration can be confusing, change the comment
> string of these users and groups, to something like
>
> "account removed"
>
> Add a group 'user-graveyard' for (3), and move these 'pseudo-removed' users
> to the 'user-graveyard' group.
> 3. Don't forget to remove graveyard users from all groups (except user-graveyard),
> make sure the graveyard users can't log in anymore ... (Perhaps add a rule to
> the SSH and PAM configuration that forbids logging in to graveyard accounts,
> by checking whether the user is in the 'user-graveyard' group?)
I would be okay with this approach as well, although it's not obvious to
me that it's any cleaner than having a separate /etc/previous-uids file,
given items 2 and 3 above.
>> Then, provide a UID/GID garbage collector, to be explicitly run by users
>> if desired, which would scan all filesystems to find the set of UID/GIDs
>> currently referenced, and remove entries from the historical mappings
>> that are no longer needed.
>
> That seems useful for if /etc/passwd and /etc/group is getting full, or just for
> cleaning up. You may want to exclude /gnu/store though, for efficiency (-:.
Good point! That's one directory that would clearly be a waste to scan :-)
> And just in case check whether any live processes have the UID/GID.
Sure, sounds good.
Thanks!
Mark
next prev parent reply other threads:[~2021-04-17 16:31 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-05 8:36 bug#36508: GDM files have incorrect owner after temporarily replacing with SDDM ison
2021-04-13 13:24 ` bug#36508: GDM files have incorrect owner after temporarily removing service Brendan Tildesley via Bug reports for GNU Guix
2021-04-13 20:51 ` Mark H Weaver
2021-04-14 4:31 ` Brendan Tildesley via Bug reports for GNU Guix
2021-04-15 18:09 ` Mark H Weaver
2021-04-14 10:32 ` Ludovic Courtès
2021-04-14 12:21 ` Brendan Tildesley via Bug reports for GNU Guix
2021-04-15 14:24 ` Ludovic Courtès
2021-04-15 18:30 ` Mark H Weaver
2021-04-15 20:05 ` Ludovic Courtès
2021-04-15 22:22 ` Mark H Weaver
2021-04-16 15:18 ` Ludovic Courtès
2021-04-17 16:16 ` Mark H Weaver
2021-04-15 23:04 ` Mark H Weaver
2021-04-16 15:14 ` Ludovic Courtès
2021-04-15 18:35 ` Mark H Weaver
2021-04-15 18:58 ` Mark H Weaver
2021-04-16 10:42 ` Maxime Devos
2021-04-17 16:28 ` Mark H Weaver [this message]
2022-09-18 12:22 ` bug#36508: [DRAFT PATCH] Stable allocation of uids, by keeping a historical mapping Maxime Devos
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