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Configuring GDM 2.2

By Mark Nielsen

Introduction
Downloading and installing GDM.
Configuring GDM
Conclusion
References

Introduction

GDM or GNOME Display Manager, is a nice GUI login screen which makes it nice and pretty to login to X-windows. It it much nicer for non-linux people to have a GUI interface to login to rather than a console.

One thing that bothered me with some of the older versions of GDM was the fact that I couldn't place the login window anywhere I wanted on the screen. With the latest version, it as very easy. Also, I couldn't figure out how to make logos of people in the login window, and now I figured that out. The latest version of GDM is really nice and I have figured out how to configure it the way I wanted it to be configured, so I finally decided to write this article.

Downloading and installing GDM.

I could have downloaded an RPM from somewhere, but instead I decided to compile it manually. I was testing it on a RH 6.2 system. As soon as I can get the 7.1 version of RH (as the 7.0 wasn't worth the trouble), I will test it on it as well, and Debian of course.

The danger of not using RPMs to install GDM, is the fact that I am installing a newer version of GDM on top of a GDM version which was installed by RPMs. This could cause problems if I decided to use an RPM in the future. I found an RPM version at ftp://ftp.gnome.org/pub/GNOME/stable/latest/redhat/i386/Base/gdm-2.2.0-1.i386.rpm in case you don't want to install it manually.

Initial Steps

Downloaded GDM from ftp://ftp.gnome.org/pub/GNOME/stable/latest/sources/gdm-2.2.0.tar.gz
tar -zxvf gdm-2.2.0.tar.gz
cd gdm-2.2.0
./configure --prefix=/usr
make
make install

After fooling around a bit, I found out that /etc/X11/gdm wasn't being used for the configuration files, so I linked /etc/X11/gdm to the place that gdm was looking. I probably could have recompiled gdm to fix this problem, but I am being lazy. Also, one directory was missing, so I created it.

Three additional Steps

mv /usr/etc/gdm /usr/etc/gdm_new
ln -s /etc/X11/gdm /usr/etc/gdm
mkdir /usr/share/faces/

Again, I emphasize the fact that you should probably use the rpm and not bother installing it manually.

Configuring GDM

The goals I had were,

Be able to place the login screen anywhere I wanted.
Be able to play a game before someone has to login.
Be able to put images in the background just for fun.
Be able to put a clock on the background.
Be able to put pictures or logos of people on the browser part of GDM.

I had to change some of the settings in the file gdm.conf. My changes were

Browser=true
SetPosition=true
PositionX=100
PositionY=100
Exclude=bin,daemon,adm,lp,sync,shutdown,halt,mail,news,uucp,operator,nobody,gdm,postgres,pvm,otherlogin
GlobalFaceDir=/usr/share/faces/

Also, here was my Init/Default script,

#!/bin/sh

/usr/X11R6/bin/xsetroot -solid "#363047"

xsri -geometry +5+5 /etc/X11/xdm/Logo2.png
xsri -geometry +400+5 /home/mark/public_html/wedding/wed2.jpg
xsri -geometry +700+500 /home/mark/public_html/wedding/walk.jpg
xsri -geometry +200+500 /home/mark/public_html/wedding/kiss.jpg

xsri -geometry +5+175 /home/mark/public_html/kiss.gif

xsri -geometry +5+500 /usr/local/apache_gnujobs/htdocs/images/zing.png

xeyes -geometry +825+5 &

xclock -digital -geometry +825+125 -update 1 &
 
xtriangles -geometry +800+300 &

In order to get logos or pictures of people on the GDM screen, I had to make the name of the image exactly the name of username and put it in /usr/share/faces/. To test this, I took my logo for ZING and copied it to "/usr/share/faces/root" like

cp /usr/local/apache_gnujobs/htdocs/images/zing.png /usr/share/faces/root

Notice that there is no extension.

Conclusion

Everything worked perfectly once I followed these steps. Using the rpm might have been easier, but oh well. I will try that out next time. I highly recommend to back up any gdm configuration files before installing any new RPMs (though the RPMs should back them up for you). I don't really see any other features that I would need. Some miscellaneous features, like maybe a ticker tape, downloading the weather, or other games besides triangles would be cool. I imagine it is possible, but it isn't necessary for me. It also might be a security risk to let people play games before they have to login, in case they figure out some way to break out to a shell, so I wouldn't advise putting games into GDM on public computers.

I would have liked to compare KDM with GDM, but I wasn't able to easily find a recent web page for KDM. I am also waiting until I install the latest version of KDE before I mess around with KDM anyways.

References

Gnome Display Manager
6-24-1999 Setting up XDM.
If this article changes, it will be available here http://www.gnujobs.com/Articles/19/GDM.html

Mark works as an independent consultant donating time to causes like GNUJobs.com, writing articles, writing free software, and working as a volunteer at eastmont.net.

Mark Nielsen

Mark works at ZING (www.genericbooks.com) and GNUJobs.com. Previously, Mark founded The Computer Underground. Mark works on non-profit and volunteer projects which promote free literature and software. To make a living, he recruits people for GNU related jobs and also provides solutions for web/database problems using Linux, FreeBSD, Apache, Zope, Perl, Python, and PostgreSQL.