GNOME Bugzilla – Bug 567522
gdm cannot be used as a simple XDMCP server
Last modified: 2013-11-11 17:19:42 UTC
Please describe the problem: When no local console exists, there is no way to run gdm in XDMCP mode only. This makes it unusable on servers like the iSeries for example. The problem has been discovered in Fedora 10 distribution package. This bug report and patch are reported here upon Fedora maintainer request and are described at https://bugzilla.redhat.com/show_bug.cgi?id=473887 Steps to reproduce: 1. Start Fedora 10 on a server without graphics terminal 2. Update /etc/gdm/gdm.schemas to allow XDMCP 3. Enter init level 5 Actual results: gdm exits because scheduler X server keeps stopping. Expected results: An operational XDMCP server ! Does this happen every time? Yes, on a server without graphics terminal Other information: I have created patch "noconsole" to add the configuration parameter "daemon/NoConsole" in /etc/gdm/gdm.schemas. This Boolean flag controls the starting of a local X terminal: setting it to "true" resolves the problem.
Created attachment 126295 [details] [review] Adds the daemon/NoConsole parameter to disable the local X terminal handling
This option is needed for headless operations. I currently have the same issue since my Ubuntu 9.10 (GDM 2.28.1) is installed as an OpenVZ client which normally does not have access to a local graphical console. I would appreciate it if this option would be enabled again.
I have just confirmed that the attached patch works with GDM 2.28.1 in Ubuntu 9.10
Thanks for the bug report. This particular bug has already been reported into our bug tracking system, but please feel free to report any further bugs you find. *** This bug has been marked as a duplicate of bug 342397 ***
I don’t think this bug is a dupe of bug#342397. It is not just about being able to deal with X crashes more gracefully, but to be able to disable local logins. Patrick’s patch is still needed for being able to do so.
gdm-binary does try to start X, and prints quite a load of messages to console. Having a manual switch ,as the attached patch does, would be very helpful.
Created attachment 187240 [details] [review] Rename the option to xdmcp/ShowLocalGreeter Renaming the option by Ray’s request. This way it is clear that the option is XDMCP related, and without XDMCP configured it will not be taken into account anyway.
Updated debian patch http://patch-tracker.debian.org/patch/series/view/gdm3/3.8.3-2/22_noconsole.patch
Created attachment 259547 [details] [review] Add an option to use GDM as a standalone XDMCP server This patch add an option (xdmcp/ShowLocalGreeter) to disable the local X console and turn GDM into a simple XDMCP server Thanks to Patrick Monnerat and Josselin Mouette for the patch
I think i probably gave bad advice re comment 7. We now, of course, support DisplayLink USB adapters too, that could also benefit from this option, and they don't use XDMCP. Also, debian has been using daemon/NoConsole for so long now, it would be good to preserve compatibility.
Josselin do you want to go ahead and push the debian patch ?
@Ray: Well the patch that I've proposed here is the patch that debian is using from quite some times now (just reworked the style a bit)
ah okay, let's just go with it then. can you push?
This problem has been fixed in the development version. The fix will be available in the next major software release. Thank you for your bug report. From b2fb259e7ba7cb029469c47a93988387349e7b2c Mon Sep 17 00:00:00 2001 From: Laurent Bigonville <bigon@bigon.be> Date: Mon, 11 Nov 2013 10:31:48 +0000 Subject: Add an option to use GDM as a standalone XDMCP server This patch add an option (xdmcp/ShowLocalGreeter) to disable the local X console and turn GDM into a simple XDMCP server Thanks to Patrick Monnerat and Josselin Mouette for the patch https://bugzilla.gnome.org/show_bug.cgi?id=567522