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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | CONFIGURATION FORMAT | APPLICABILITY | SEE ALSO | NOTES | COLOPHON |
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ENVIRONMENT.D(5) environment.d ENVIRONMENT.D(5)
environment.d - Definition of user service environment
~/.config/environment.d/*.conf
/etc/environment.d/*.conf
/run/environment.d/*.conf
/usr/local/lib/environment.d/*.conf
/usr/lib/environment.d/*.conf
/etc/environment
Configuration files in the environment.d/ directories contain
lists of environment variable assignments passed to services
started by the systemd user instance.
systemd-environment-d-generator(8) parses them and updates the
environment exported by the systemd user instance. See below for
an discussion of which processes inherit those variables.
It is recommended to use numerical prefixes for file names to
simplify ordering.
For backwards compatibility, a symlink to /etc/environment is
installed, so this file is also parsed.
Configuration files are read from directories in /etc/, /run/,
/usr/local/lib/, and /usr/lib/, in order of precedence, as listed
in the SYNOPSIS section above. Files must have the ".conf"
extension. Files in /etc/ override files with the same name in
/run/, /usr/local/lib/, and /usr/lib/. Files in /run/ override
files with the same name under /usr/.
All configuration files are sorted by their filename in
lexicographic order, regardless of which of the directories they
reside in. If multiple files specify the same option, the entry
in the file with the lexicographically latest name will take
precedence. Thus, the configuration in a certain file may either
be replaced completely (by placing a file with the same name in a
directory with higher priority), or individual settings might be
changed (by specifying additional settings in a file with a
different name that is ordered later).
Packages should install their configuration files in /usr/lib/
(distribution packages) or /usr/local/lib/ (local installs) [1].
Files in /etc/ are reserved for the local administrator, who may
use this logic to override the configuration files installed by
vendor packages.
It is recommended to prefix all filenames with a two-digit number
and a dash to simplify the ordering. It is recommended to use the
range 10-40 for configuration files in /usr/ and the range 60-90
for configuration files in /etc/ and /run/, to make sure that
local and transient configuration files will always take priority
over configuration files shipped by the OS vendor.
If the administrator wants to disable a configuration file
supplied by the vendor, the recommended way is to place a symlink
to /dev/null in the configuration directory in /etc/, with the
same filename as the vendor configuration file. If the vendor
configuration file is included in the initrd image, the image has
to be regenerated.
The configuration files contain a list of "KEY=VALUE" environment
variable assignments, separated by newlines. The right hand side
of these assignments may reference previously defined environment
variables, using the "${OTHER_KEY}" and "$OTHER_KEY" format. It
is also possible to use "${FOO:-DEFAULT_VALUE}" to expand in the
same way as "${FOO}" unless the expansion would be empty, in
which case it expands to DEFAULT_VALUE, and use
"${FOO:+ALTERNATE_VALUE}" to expand to ALTERNATE_VALUE as long as
"${FOO}" would have expanded to a non-empty value. No other
elements of shell syntax are supported.
Each KEY must be a valid variable name. Empty lines and lines
beginning with the comment character "#" are ignored.
Example
Example 1. Setup environment to allow access to a program
installed in /opt/foo
/etc/environment.d/60-foo.conf:
FOO_DEBUG=force-software-gl,log-verbose
PATH=/opt/foo/bin:$PATH
LD_LIBRARY_PATH=/opt/foo/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
XDG_DATA_DIRS=/opt/foo/share:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share/}
Environment variables exported by the user service manager
(systemd --user instance started in the user@uid.service system
service) are passed to any services started by that service
manager. In particular, this may include services which run user
shells. For example in the GNOME environment, the graphical
terminal emulator runs as the gnome-terminal-server.service user
unit, which in turn runs the user shell, so that shell will
inherit environment variables exported by the user manager. For
other instances of the shell, not launched by the user service
manager, the environment they inherit is defined by the program
that starts them. Hint: in general, systemd.service(5) units
contain programs launched by systemd, and systemd.scope(5) units
contain programs launched by something else.
Note that these files do not affect the environment block of the
service manager itself, but exclusively the environment blocks
passed to the services it manages. Environment variables set that
way thus cannot be used to influence behaviour of the service
manager. In order to make changes to the service manager's
environment block the environment must be modified before the
user's service manager is invoked, for example from the system
service manager or via a PAM module.
Specifically, for ssh logins, the sshd(8) service builds an
environment that is a combination of variables forwarded from the
remote system and defined by sshd, see the discussion in ssh(1).
A graphical display session will have an analogous mechanism to
define the environment. Note that some managers query the systemd
user instance for the exported environment and inject this
configuration into programs they start, using systemctl
show-environment or the underlying D-Bus call.
systemd(1), systemd-environment-d-generator(8),
systemd.environment-generator(7)
1. 💣💥🧨💥💥💣 Please note that those configuration files must
be available at all times. If /usr/local/ is a separate
partition, it may not be available during early boot, and
must not be used for configuration.
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
This page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
[email protected]
systemd 257~devel ENVIRONMENT.D(5)
Pages that refer to this page: systemd.directives(7), systemd.index(7), systemd-environment-d-generator(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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