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Can't configure GDM after update to CentOS 7.6

Hi,

It looks like the upgrade to CentOS 7.6 has been unusually disruptive
with the GNOME desktop version bump and a series of moving targets under
the hood. The result is some wreckage at my client's desktop
installations, which I've been busy to repair since yesterday. First
things first.

I have a custom configuration of GDM, which consists mainly of two things.

1. Display my company's logo instead of the CentOS logo.

2. Disable the user list (since I have about 100 users here).

Until CentOS 7.5, here's what I did.

1. Create a file /etc/dconf/profile/gdm :

user-db:user
system-db:gdm
file-db:/usr/share/gdm/greeter-dconf-defaults

2. Create a file /etc/dconf/db/gdm.d/01-logo :

[org/gnome/login-screen]
logo='/usr/share/pixmaps/microlinux-logo.png'

3. Create a file /etc/dconf/db/gdm.d/00-login-screen :

[org/gnome/login-screen]
disable-user-list=true

4. Update dconf :

# dconf update

Now with CentOS 7.6 this doesn't work anymore. The /etc/dconf/db/gdm.d
directory is nowhere to be found, and I'm currently mildly cursing the
GNOME developers' (and Red Hat's) policy of releasing moving targets.
Until now, the whole purpose of Enterprise Linux seemed to be low-risk
updates. </rant>

I've documented the whole GDM customization process until CentOS 7.5 in
a short article on my french blog :

* <a href="https://blog.microlinux.fr/gdm-centos/" title="https://blog.microlinux.fr/gdm-centos/">https://blog.microlinux.fr/gdm-centos/</a>

Any idea how I can configure GDM with the new version ?

Cheers,

Niki

Comments

Re: Can't configure GDM after update to CentOS 7.6

By Jonathan Billings at 12/06/2018 - 09:41

On Thu, Dec 06, 2018 at 10:01:25AM +0100, Nicolas Kovacs wrote:
While the /etc/dconf/db/gdm.d/ directory doesn't exist, I've got many
RHEL7.6 and CentOS 7.6 systems where GDM behaves the same way as
before, as long as you create /etc/dconf/db/gdm.d/ and put the files
in there, and as soon as you run 'dconf update', you see it change.

I'm not sure why the /etc/dconf/db/gdm.d/ and
/etc/dconf/db/gdm.d/locks/ directory aren't owned by a package
anymore, that seems like a bug, but as far as I can tell, GDM
continues to get its information from there.

Re: Can't configure GDM after update to CentOS 7.6

By James Pearson at 12/06/2018 - 10:24

Jonathan Billings wrote:
I suspect it might be something that has been left out in the rebase to
GDM 3.28.1 - an earlier change log for GDM has:

* Thu Jun 25 2015 Ray Strode < ... at redhat dot com> 3.14.2-4
- Make sure user customizations to gdm via /etc/dconf/db/gdm.d
continue to work following rebase.
Related: #1174564

So, I'm guessing that something similar was left out with this change
from 3.26 to 3.28 ?

Maybe a bug report to <a href="https://bugzilla.redhat.com" title="https://bugzilla.redhat.com">https://bugzilla.redhat.com</a> is needed ?

James Pearson

Re: Can't configure GDM after update to CentOS 7.6

By Niki Kovacs at 12/06/2018 - 12:10

Le 06/12/2018 à 15:24, James Pearson a écrit :
On a side note, I've now spent a day and a half trying to recover my
wrecked desktop profiles, with only a partial success. As it looks now,
I'll probably move all my desktop installations to openSUSE Leap 15 and
KDE 5 in the near future.

As far as I can tell, rebasing GNOME in the middle of a minor update was
not a good idea.

Cheers,

Niki

Re: Can't configure GDM after update to CentOS 7.6

By Alice Wonder at 12/06/2018 - 12:56

On 12/06/2018 08:10 AM, Nicolas Kovacs wrote:
They did a similar thing with NetworkManager few releases ago that
caused all my servers to start grabbing randomized IPv6 addresses
instead of static they previously grabbed.

I don't understand why Red Hat makes these kind of changes in point
releases - yet they won't update OpenSSL or PHP or Postfix in a point
release.

It's like they use /dev/random to determibe where they require API
stability between point releases.

Re: Can't configure GDM after update to CentOS 7.6

By John Hodrien at 12/06/2018 - 13:54

Rebasing Gnome3 regularly I think has been one of Red Hat's best decisions,
and one I can easily imagine a committee deciding against for reasons of
wanting to minimise risk.

Do you remember just how bad Gnome3 was in RHEL 7.0? It was unstable and
insecure, certainly when used with nvidia drivers. I can't see how you could
justify the effort it would have required to effectively support an
unsupported version of Gnome3, and backporting I think would have been more
than deeply unpleasant.

They made a mistake in omitting a patch that wasn't caught in qa, and that's a
shame. But then let's be honest, how many Red Hat customers actually use this
feature? I do use it, and I didn't pick it up in my own testing, as our
deployment must have created the directories as we had no issues.

jh

Re: Can't configure GDM after update to CentOS 7.6

By Niki Kovacs at 12/06/2018 - 16:30

Le 06/12/2018 à 18:54, John Hodrien a écrit :
Or they could simply have gone with KDE 4, a stable and mature desktop
at the time RHEL 7.0 was out. And not an abomination that had to be
potty-trained from scratch again while steadily losing features every
other minor upgrade.

Niki

Re: Can't configure GDM after update to CentOS 7.6

By Johnny Hughes at 12/07/2018 - 11:24

On 12/6/18 2:30 PM, Nicolas Kovacs wrote:
Well that is one person's opinion on the KDE/GNOME debate .. mine would
be slightly different (OK , completely opposite :)

To each his own :)

Re: Can't configure GDM after update to CentOS 7.6

By m.roth at 12/07/2018 - 12:42

Johnny Hughes wrote:
I'm in the gnome is crap camp. Bloatware (which is what kde used to
be...), and it looks like it's trying, real hard, to make users think of
Windows 10 (which, having had to deal with, I LOATHE!!!!!)

Kde looks like *Nix. I like things wo work the way I want, and no, the way
they want to do it isn't how I want it... which, of course, is the *Nix
Way.

mark