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diff --git a/man/systemd.preset.xml b/man/systemd.preset.xml new file mode 100644 index 0000000000..a692053876 --- /dev/null +++ b/man/systemd.preset.xml @@ -0,0 +1,204 @@ +<?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 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> |