elogind

From Gentoo Wiki
Jump to:navigation Jump to:search
Translate this page
Other languages:

Warning: Display title "elogind" overrides earlier display title "Elogind".

elogind is the systemd project's logind, extracted to a standalone package. It's designed for users who prefer a non-systemd init system, but still want to use popular software such as KDE or GNOME that otherwise hard-depends on systemd.

Installation

Kernel

The following kernel options are recommended:

KERNEL 
General setup  --->
    [*] Control Group support  --->
File systems  --->
    [*] Inotify support for userspace

In the unlikely (and not recommended) event that standard kernel features are enabled for manual configuration, elogind also requires eventpoll, signalfd() and timerfd() support. Most users can ignore this.

USE flags

USE flags for sys-auth/elogind The systemd project's logind, extracted to a standalone package

acl Add support for Access Control Lists
audit Enable support for Linux audit subsystem using sys-process/audit
cgroup-hybrid Use hybrid cgroup hierarchy (OpenRC's default) instead of unified.
debug Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
doc Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
pam Add support for PAM (Pluggable Authentication Modules) - DANGEROUS to arbitrarily flip
policykit Enable PolicyKit (polkit) authentication support
selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
test Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
Data provided by the Gentoo Package Database · Last update: 2023-08-26 16:04 More information about USE flags

There is a global elogind USE flag for enabling elogind support in other packages. It's also recommended to disable support for other session trackers (systemd) to avoid conflicts:

FILE /etc/portage/make.conf
USE="elogind -systemd"
Warning
Using elogind and systemd at the same time is untested and not advised!

Emerge

After updating the USE flags update the system so the changes take effect:

root #emerge --ask --changed-use --deep @world

Configuration

Service

elogind should be configured to start at boot time:

root #rc-update add elogind boot

When D-Bus is installed with the USE="elogind" flag, starting elogind on boot triggers the dbus system daemon to load automatically.

Alternatively, elogind can be launched on-demand by the first program that requests it (like a compatible display manager), through the system dbus service.

Warning
If there are problems getting poweroff/reboot/suspend etc. working from desktop environment, putting elogind into boot runlevel will make sure the elogind-daemon is started properly before any user is logged in, and so should fix the problem.

Additionally, if built with USE=pam, elogind will be activated when the first user logs into the system.

Warning
In order to trigger elogind to activate a session on first on a VT console terminal, sys-apps/shadow has to be built with the pam USE flag also, since it provides /bin/login. This concept also applies to any other graphical login managers or alternative terminal login programs used. In that case, they should be built with PAM too.

startx D-Bus integration

To have an elogind session created when using startx to start the X server (instead of a display manager), add the following to the user's ~/.xinitrc file:

FILE ~/.xinitrc
exec dbus-launch --exit-with-session <WINDOW_MANAGER>

WINDOW_MANAGER in the above example needs to be replaced by a window manager or a single application.

Tip
This exec command launches dbus-daemon --system, which launches your WM. No further commands will be executed if placed after this "exec" line

Suspend/Hibernate Resume/Thaw hook scripts

With elogind the situation is much handier. Any suspend/resume and hibernate/thaw hook scripts need to be in the directory /lib64/elogind/system-sleep/ and use the variables $1 (pre or post) and $2 (suspend, hibernate, or hybrid-sleep). For example, in the case of elogind a hook script could have the following format:

FILE /lib64/elogind/system-sleep/example.shAn example of elogind hook
#!/bin/bash
case $1/$2 in
  pre/*)
    # Put here any commands expected to be run when suspending or hibernating.
    ;;
  post/*)
    # Put here any commands expected to be run when resuming from suspension or thawing from hibernation.
    ;;
esac

Do not forget to make the hook scripts executable:

root #chmod +x /lib64/elogind/system-sleep/example.sh

Usage

loginctl

The command loginctl may be used to control and introspect the login manager. For example, to shut down or reboot the system:

user $loginctl poweroff
user $loginctl reboot

For example, to suspend, hibernate or hybrid-suspend the system:

user $loginctl suspend
user $loginctl hibernate
user $loginctl hybrid-sleep

To suspend the system and then hibernate after a period of inactivity while the system is suspended:

user $loginctl suspend-then-hibernate

where hibernation delay can be specified in /etc/elogind/logind.conf.

Troubleshooting

Confirmation of full functionality

Running loginctl itself will indicate ALL sessions/seats/users/tty's for which elogind has been fully activated. For example:

user $loginctl
SESSION  UID USER      SEAT  TTY 
      1    0 root      seat0 tty1
      2 1000 larry     seat0 tty2
 
2 sessions listed.

Checking for the presence of XDG environment variables should produce similar results, even before a GUI is loaded. For example:

user $env | grep "XDG" 
XDG_CONFIG_DIRS=/etc/xdg:/etc/xdg
XDG_SEAT=seat0
XDG_SESSION_TYPE=tty
XDG_SESSION_CLASS=user
XDG_VTNR=2
XDG_SESSION_ID=2
XDG_RUNTIME_DIR=/run/user/1000
XDG_DATA_DIRS=/usr/local/share:/usr/share:/usr/share

Conflict when using hidepid in proc

When procfs is mounted with hidepid=2 and gid=wheel, there will be conflicts with elogind. In order to change this, the gid needs to be changed to gid=polkitd.

See also this forum post https://forums.gentoo.org/viewtopic-t-1099870.html

PAM

If using USE=pam, make sure there are no conflicting pending changes waiting to be written to /etc (run etc-update or dispatch-conf to merge any /etc/pam.d conflicts.)

Confirm these changes took place in these two /etc/pam.d files:

user $grep -r "elogind" /etc/pam.d/ 
/etc/pam.d/elogind-user: session optional pam_elogind.so
/etc/pam.d/system-login: -session        optional        pam_elogind.so

External resources

Retrieved from "https://wiki.gentoo.org/index.php?title=Elogind/en&oldid=1235973"