Introduction to Lightdm
The lightdm package contains a
lightweight display manager based upon GTK.
This package is known to build and work properly using an LFS-11.0
platform.
Lightdm Package Information
Additional download
![[Note]](../images/note.png)
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-4.16.2 (for the greeter), libgcrypt-1.9.4, itstool-2.0.6,
Linux-PAM-1.5.1, and PCRE-8.45
Recommended
gobject-introspection-1.68.0,
libxklavier-5.4, and Vala-0.52.5
Optional
AccountsService-0.6.55 (run time),
at-spi2-core-2.40.3, GTK-Doc-1.33.2, Qt-5.15.2, libido, and libindicator
User Notes: https://wiki.linuxfromscratch.org/blfs/wiki/lightdm
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-1.30.0 &&
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-20210826 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
Alternatively the runlevel can be permanently set to 5, starting
the lightdm greeter
screen automatically, by modifying /etc/inittab. As the root user:
cp -v /etc/inittab{,-orig} &&
sed -i '/initdefault/ s/3/5/' /etc/inittab
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.