+++ /dev/null
-<?xml version="1.0"?>
-<!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-<!--
- This file is part of systemd.
-
- Copyright 2011 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
-<refentry id="systemd.preset">
-
- <refentryinfo>
- <title>systemd.preset</title>
- <productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
- </refentryinfo>
-
- <refmeta>
- <refentrytitle>systemd.preset</refentrytitle>
- <manvolnum>5</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>systemd.preset</refname>
- <refpurpose>Service enablement presets</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <para><filename>/etc/systemd/system-preset/*.preset</filename></para>
- <para><filename>/run/systemd/system-preset/*.preset</filename></para>
- <para><filename>/usr/lib/systemd/system-preset/*.preset</filename></para>
- <para><filename>/etc/systemd/user-preset/*.preset</filename></para>
- <para><filename>/run/systemd/user-preset/*.preset</filename></para>
- <para><filename>/usr/lib/systemd/user-preset/*.preset</filename></para>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para>Preset files may be used to encode policy which units shall
- be enabled by default and which ones shall be disabled. They are
- read by <command>systemctl preset</command> (for more information
- see
- <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>)
- which uses this information to enable or disable a unit according
- to preset policy. <command>systemctl preset</command> is used by
- the post install scriptlets of RPM packages (or other OS package
- formats), to enable/disable specific units by default on package
- installation, enforcing distribution, spin or administrator preset
- policy. This allows choosing a certain set of units to be
- enabled/disabled even before installing the actual package.</para>
-
- <para>For more information on the preset logic please have a look
- at the <ulink
- url="http://freedesktop.org/wiki/Software/systemd/Preset">Presets</ulink>
- document.</para>
-
- <para>It is not recommended to ship preset files within the
- respective software packages implementing the units, but rather
- centralize them in a distribution or spin default policy, which
- can be amended by administrator policy.</para>
-
- <para>If no preset files exist, <command>systemctl
- preset</command> will enable all units that are installed by
- default. If this is not desired and all units shall rather be
- disabled, it is necessary to ship a preset file with a single,
- catchall "<filename>disable *</filename>" line. (See example 1,
- below.)</para>
- </refsect1>
-
- <refsect1>
- <title>Preset File Format</title>
-
- <para>The preset files contain a list of directives consisting of
- either the word <literal>enable</literal> or
- <literal>disable</literal> followed by a space and a unit name
- (possibly with shell style wildcards), separated by newlines.
- Empty lines and lines whose first non-whitespace character is # or
- ; are ignored.</para>
-
- <para>Two different directives are understood:
- <literal>enable</literal> may be used to enable units by default,
- <literal>disable</literal> to disable units by default.</para>
-
- <para>If multiple lines apply to a unit name, the first matching
- one takes precedence over all others.</para>
-
- <para>Each preset file shall be named in the style of
- <filename><priority>-<program>.conf</filename>. Files
- in <filename>/etc/</filename> override files with the same name in
- <filename>/usr/lib/</filename> and <filename>/run/</filename>.
- Files in <filename>/run/</filename> override files with the same
- name in <filename>/usr/lib/</filename>. Packages should install
- their preset files in <filename>/usr/lib/</filename>. Files in
- <filename>/etc/</filename> are reserved for the local
- administrator, who may use this logic to override the preset files
- installed by vendor packages. All preset files are sorted by their
- filename in lexicographic order, regardless of which of the
- directories they reside in. If multiple files specify the same
- unit name, the entry in the file with the lexicographically
- earliest name will be applied. It is recommended to prefix all
- filenames with a two-digit number and a dash, to simplify the
- ordering of the files.</para>
-
- <para>If the administrator wants to disable a preset file supplied
- by the vendor, the recommended way is to place a symlink to
- <filename>/dev/null</filename> in
- <filename>/etc/systemd/system-preset/</filename> bearing the same
- filename.</para>
- </refsect1>
-
- <refsect1>
- <title>Example</title>
-
- <example>
- <title>Default off example <filename>/usr/lib/systemd/system-preset/99-default.preset</filename>:</title>
-
- <programlisting>disable *</programlisting>
- </example>
-
- <para>This disables all units. Due to the filename prefix
- <literal>99-</literal>, it will be read last and hence can easily
- be overridden by spin or administrator preset policy or
- suchlike.</para>
-
- <example>
- <title>A GNOME spin example <filename>/usr/lib/systemd/system-preset/50-gnome.preset</filename>:</title>
-
- <programlisting>enable gdm.service
-enable colord.service
-enable accounts-daemon.service
-enable avahi-daemon.*</programlisting>
-
- </example>
-
- <para>This enables the three mentioned units, plus all
- <filename>avahi-daemon</filename> regardless of which unit type. A
- file like this could be useful for inclusion in a GNOME spin of a
- distribution. It will ensure that the units necessary for GNOME
- are properly enabled as they are installed. It leaves all other
- units untouched, and subject to other (later) preset files, for
- example like the one from the first example above.</para>
-
- <example>
- <title>Administrator policy <filename>/etc/systemd/system-preset/00-lennart.preset</filename>:</title>
-
- <programlisting>enable httpd.service
-enable sshd.service
-enable postfix.service
-disable *</programlisting>
- </example>
-
- <para>This enables three specific services and disables all
- others. This is useful for administrators to specifically select
- the units to enable, and disable all others. Due to the filename
- prefix <literal>00-</literal> it will be read early and hence
- overrides all other preset policy files.</para>
- </refsect1>
-
- <refsect1>
- <title>See Also</title>
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- </para>
- </refsect1>
-
-</refentry>
~ianmdlvl / elogind.git / blobdiff