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diff --git a/man/environment.d.xml b/man/environment.d.xml new file mode 100644 index 0000000..fc03405 --- /dev/null +++ b/man/environment.d.xml @@ -0,0 +1,133 @@ +<?xml version="1.0"?> +<!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- + SPDX-License-Identifier: LGPL-2.1-or-later + + Copyright © 2016 Red Hat, Inc. +--> +<refentry id="environment.d" conditional='ENABLE_ENVIRONMENT_D' + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>environment.d</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>environment.d</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>environment.d</refname> + <refpurpose>Definition of user service environment</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>~/.config/environment.d/*.conf</filename></para> + <para><filename>/etc/environment.d/*.conf</filename></para> + <para><filename>/run/environment.d/*.conf</filename></para> + <para><filename>/usr/lib/environment.d/*.conf</filename></para> + <para><filename>/etc/environment</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>Configuration files in the <filename>environment.d/</filename> directories contain lists of + environment variable assignments passed to services started by the systemd user instance. + <citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> + parses them and updates the environment exported by the systemd user instance. See below for an + discussion of which processes inherit those variables.</para> + + <para>It is recommended to use numerical prefixes for file names to simplify ordering.</para> + + <para>For backwards compatibility, a symlink to <filename>/etc/environment</filename> is + installed, so this file is also parsed.</para> + </refsect1> + + <xi:include href="standard-conf.xml" xpointer="confd" /> + + <refsect1> + <title>Configuration Format</title> + + <para>The configuration files contain a list of + <literal><replaceable>KEY</replaceable>=<replaceable>VALUE</replaceable></literal> environment + variable assignments, separated by newlines. The right hand side of these assignments may + reference previously defined environment variables, using the <literal>${OTHER_KEY}</literal> + and <literal>$OTHER_KEY</literal> format. It is also possible to use + <literal>${<replaceable>FOO</replaceable>:-<replaceable>DEFAULT_VALUE</replaceable>}</literal> + to expand in the same way as <literal>${<replaceable>FOO</replaceable>}</literal> unless the + expansion would be empty, in which case it expands to <replaceable>DEFAULT_VALUE</replaceable>, + and use + <literal>${<replaceable>FOO</replaceable>:+<replaceable>ALTERNATE_VALUE</replaceable>}</literal> + to expand to <replaceable>ALTERNATE_VALUE</replaceable> as long as + <literal>${<replaceable>FOO</replaceable>}</literal> would have expanded to a non-empty value. + No other elements of shell syntax are supported.</para> + + <para>Each <replaceable>KEY</replaceable> must be a valid variable name. Empty lines + and lines beginning with the comment character <literal>#</literal> are ignored.</para> + + <refsect2> + <title>Example</title> + <example> + <title>Setup environment to allow access to a program installed in + <filename index="false">/opt/foo</filename></title> + + <para><filename index="false">/etc/environment.d/60-foo.conf</filename>: + </para> + <programlisting> + 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/} + </programlisting> + </example> + </refsect2> + </refsect1> + + <refsect1> + <title>Applicability</title> + + <para>Environment variables exported by the user service manager (<command>systemd --user</command> + instance started in the <filename>user@<replaceable>uid</replaceable>.service</filename> 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 + <filename>gnome-terminal-server.service</filename> 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, + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> units + contain programs launched by systemd, and + <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry> units + contain programs launched by something else.</para> + + <para>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.</para> + + <para>Specifically, for ssh logins, the + <citerefentry project='die-net'><refentrytitle>sshd</refentrytitle><manvolnum>8</manvolnum></citerefentry> + service builds an environment that is a combination of variables forwarded from the remote system and + defined by <command>sshd</command>, see the discussion in + <citerefentry project='die-net'><refentrytitle>ssh</refentrytitle><manvolnum>1</manvolnum></citerefentry>. + 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 <command>systemctl show-environment</command> or the underlying D-Bus call. + </para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.environment-generator</refentrytitle><manvolnum>7</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |