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-4.20.0 (for the greeter), libgcrypt-1.11.0, itstool-2.0.7,
Linux-PAM-1.7.0, and Xorg-Server-21.1.14 (Runtime)
Recommended
GLib-2.82.4 (with GObject Introspection),
libxklavier-5.4, and Vala-0.56.17
Optional
AccountsService-23.13.9 (run time),
at-spi2-core-2.54.0, GTK-Doc-1.34.0, 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
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-2.0.9.tar.gz &&
cd lightdm-gtk-greeter-2.0.9 &&
./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-2.0.9 &&
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,lightdm-gtk-greeter}.conf
The configuration files offer many options. If, for instance, you
have a multiple monitor setup but prefer the login window to be
displayed on only one monitor, set
'active-monitor=<monitor-name>' in lightdm-gtk-greeter.conf. For example you could
use active-monitor=HDMI-1. You can
determine the monitor-names with xrandr --listmonitors. Note
that the monitor names may change if you change the graphics
driver and you may have to adjust the configuration accordingly.
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.