--- /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
+ services 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>It is not recommended to ship preset files
+ within the respective software packages implementing
+ the services, 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 alphabetical
+ order, regardless in which of the directories they
+ reside, to guarantee that a specific preset file takes
+ precedence over another file with an alphabetically
+ earlier name, if both files contain lines that apply
+ to the same unit names. It is recommended to prefix
+ all file names with two-digit number, to simplify
+ ordering.</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 file name.</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 file name
+ 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 file name 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 / commitdiff