Introduction to Lightdm
The lightdm package contains a lightweight display manager based upon GTK.
![[Note]](../images/note.png)
Note
Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.
Lightdm Package Information
Additional download
Note
The greeter is a program to present a graphical login screen. There are several alternative greeters, but the gtk+ package is the reference implementation. For a list of other greeters, see https://en.wikipedia.org/wiki/LightDM.
Lightdm Dependencies
Required
Exo-4.18.0 (for the greeter), libgcrypt-1.10.3, itstool-2.0.7, Linux-PAM-1.6.0, and Xorg-Server-21.1.11 (Runtime)
Recommended
gobject-introspection-1.78.1, libxklavier-5.4, and Vala-0.56.14
Optional
AccountsService-23.13.9 (run time), at-spi2-core-2.50.1, GTK-Doc-1.33.2, (Qt-5.15.12 or qt-alternate-5.15.12), libido, and libindicator
Installation of Lightdm
First, create a dedicated user and group to take control of the lightdm daemon after it is started. Issue the following commands as the root user:
groupadd -g 65 lightdm &&
useradd -c "Lightdm Daemon" \
-d /var/lib/lightdm \
-u 65 -g lightdm \
-s /bin/false lightdm
Then change the Linux-PAM configuration files so that elogind is used:
sed -i s/systemd/elogind/ data/pam/*
Install lightdm by running the following commands:
./configure --prefix=/usr \
--libexecdir=/usr/lib/lightdm \
--localstatedir=/var \
--sbindir=/usr/bin \
--sysconfdir=/etc \
--disable-static \
--disable-tests \
--with-greeter-user=lightdm \
--with-greeter-session=lightdm-gtk-greeter \
--docdir=/usr/share/doc/lightdm-1.32.0 &&
make
This package does not come with a test suite.
Now, as the root user:
make install &&
cp tests/src/lightdm-session /usr/bin &&
sed -i '1 s/sh/bash --login/' /usr/bin/lightdm-session &&
rm -rf /etc/init &&
install -v -dm755 -o lightdm -g lightdm /var/lib/lightdm &&
install -v -dm755 -o lightdm -g lightdm /var/lib/lightdm-data &&
install -v -dm755 -o lightdm -g lightdm /var/cache/lightdm &&
install -v -dm770 -o lightdm -g lightdm /var/log/lightdm
Now build the greeter:
tar -xf ../lightdm-gtk-greeter-2.0.8.tar.gz &&
cd lightdm-gtk-greeter-2.0.8 &&
./configure --prefix=/usr \
--libexecdir=/usr/lib/lightdm \
--sbindir=/usr/bin \
--sysconfdir=/etc \
--with-libxklavier \
--enable-kill-on-sigterm \
--disable-libido \
--disable-libindicator \
--disable-static \
--disable-maintainer-mode \
--docdir=/usr/share/doc/lightdm-gtk-greeter-2.0.8 &&
make
Now, as the root user:
make install
Note
If you installed Xorg in /opt, you will need to create a symbolic link so lightdm can find the Xorg server. As the root user:
ln -sf /opt/xorg/bin/Xorg /usr/bin/X
Command Explanations
sed ... /usr/bin/lightdm-session: This command ensures that the initial login via the greeter sources /etc/profile and ~/.bash_profile. Without this, commands that depend on different environment variables may not work as expected.
Configuring lightdm
Config Files
/etc/lightdm/{lightdm,users,keys}.conf
Boot Script
To start lightdm automatically when the system is switched to runlevel 5, install the /etc/rc.d/init.d/xdm script and the /etc/sysconfig/xdm configuration file included in the blfs-bootscripts-20231119 package and adjust /etc/inittab by running as the root user:
make install-lightdm
Starting lightdm
The lightdm greeter can be started from the command line as the root user:
telinit 5
Available Sessions
The greeter offers a list of available sessions, depending on the Window Managers and Desktop Environments installed. The list includes sessions which have a corresponding .desktop file installed under /usr/share/xsessions. Most of the Window Managers and Desktop Environments automatically provide those files, but if necessary, you may include a custom one.