[thirdparty/systemd.git] / man / systemd.preset.xml

<?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">
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  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
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<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>&lt;priority&gt;-&lt;program&gt;.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>
Commit	Line	Data
75d67e68 LP	1	<?xml version="1.0"?>
	2	<!---nxml--->
	3	<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
	4	<!--
	5	This file is part of systemd.
	6
	7	Copyright 2011 Lennart Poettering
	8
	9	systemd is free software; you can redistribute it and/or modify it
	10	under the terms of the GNU Lesser General Public License as published by
	11	the Free Software Foundation; either version 2.1 of the License, or
	12	(at your option) any later version.
	13
	14	systemd is distributed in the hope that it will be useful, but
	15	WITHOUT ANY WARRANTY; without even the implied warranty of
	16	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	Lesser General Public License for more details.
	18
	19	You should have received a copy of the GNU Lesser General Public License
	20	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	21	-->
	22	<refentry id="systemd.preset">
	23
	24	<refentryinfo>
	25	<title>systemd.preset</title>
	26	<productname>systemd</productname>
	27
	28	<authorgroup>
	29	<author>
	30	<contrib>Developer</contrib>
	31	<firstname>Lennart</firstname>
	32	<surname>Poettering</surname>
	33	<email>lennart@poettering.net</email>
	34	</author>
	35	</authorgroup>
	36	</refentryinfo>
	37
	38	<refmeta>
	39	<refentrytitle>systemd.preset</refentrytitle>
	40	<manvolnum>5</manvolnum>
	41	</refmeta>
	42
	43	<refnamediv>
	44	<refname>systemd.preset</refname>
	45	<refpurpose>Service enablement presets</refpurpose>
	46	</refnamediv>
	47
	48	<refsynopsisdiv>
	49	<para><filename>/etc/systemd/system-preset/*.preset</filename></para>
	50	<para><filename>/run/systemd/system-preset/*.preset</filename></para>
	51	<para><filename>/usr/lib/systemd/system-preset/*.preset</filename></para>
	52	<para><filename>/etc/systemd/user-preset/*.preset</filename></para>
	53	<para><filename>/run/systemd/user-preset/*.preset</filename></para>
	54	<para><filename>/usr/lib/systemd/user-preset/*.preset</filename></para>
	55	</refsynopsisdiv>
	56
	57	<refsect1>
	58	<title>Description</title>
	59
	60	<para>Preset files may be used to encode policy which
	61	services shall be enabled by default and which ones
	62	shall be disabled. They are read by <command>systemctl
	63	preset</command> (for more information see
	64	<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>)
65	which uses this information to enable or disable a
66	unit according to preset policy. <command>systemctl
67	preset</command> is used by the post install
68	scriptlets of RPM packages (or other OS package formats),
69	to enable/disable specific units by default on package
70	installation, enforcing distribution, spin or
71	administrator preset policy. This allows choosing a certain
72	set of units to be enabled/disabled even before
73	installing the actual package.</para>
74
75	<para>It is not recommended to ship preset files
76	within the respective software packages implementing
77	the services, but rather centralize them in a
78	distribution or spin default policy, which can be
79	amended by administrator policy.</para>
80
81	<para>If no preset files exist, <command>systemctl
82	preset</command> will enable all units that are
83	installed by default. If this is not desired and all
84	units shall rather be disabled it is necessary to ship
85	a preset file with a single, catchall
86	"<filename>disable *</filename>" line. (See example 1,
87	below.)</para>
88	</refsect1>
89
90	<refsect1>
91	<title>Preset File Format</title>
92
93	<para>The preset files contain a list of
94	directives consisting of either the word
95	<literal>enable</literal> or
96	<literal>disable</literal> followed by a space and a
97	unit name (possibly with shell style wildcards),
98	separated by newlines. Empty lines and lines whose
99	first non-whitespace character is # or ; are
100	ignored.</para>
101
102	<para>Two different directives are understood:
103	<literal>enable</literal> may be used to enable units
104	by default, <literal>disable</literal> to disable
105	units by default.</para>
106
107	<para>If multiple lines apply to a unit name the
108	first matching one takes precedence over all
109	others.</para>
110
111	<para>Each preset file shall be named in the style of
112	<filename><priority>-<program>.conf</filename>.
113	Files in <filename>/etc/</filename> override files
114	with the same name in <filename>/usr/lib/</filename>
115	and <filename>/run/</filename>. Files in
116	<filename>/run/</filename> override files with the
117	same name in <filename>/usr/lib/</filename>. Packages
118	should install their preset files in
119	<filename>/usr/lib/</filename>. Files in
120	<filename>/etc/</filename> are reserved for the local
121	administrator, who may use this logic to override the
122	preset files installed by vendor packages. All preset
123	files are sorted by their filename in alphabetical
124	order, regardless in which of the directories they
125	reside, to guarantee that a specific preset file takes
126	precedence over another file with an alphabetically
127	earlier name, if both files contain lines that apply
128	to the same unit names. It is recommended to prefix
129	all file names with two-digit number, to simplify
130	ordering.</para>
131
132	<para>If the administrator wants to disable a preset
133	file supplied by the vendor the recommended way is to
134	place a symlink to <filename>/dev/null</filename> in
135	<filename>/etc/systemd/system-preset/</filename>
136	bearing the same file name.</para>
137	</refsect1>
138
139	<refsect1>
140	<title>Example</title>
141
142	<example>
143	<title>Default off example <filename>/usr/lib/systemd/system-preset/99-default.preset</filename>:</title>
144
145	<programlisting>disable *</programlisting>
146	</example>
147
148	<para>This disables all units. Due to the file name
149	prefix <literal>99-</literal> it will be read last and
150	hence can easily be overridden by spin or
151	administrator preset policy or suchlike.</para>
152
153	<example>
154	<title>A GNOME spin example <filename>/usr/lib/systemd/system-preset/50-gnome.preset</filename>:</title>
155
156	<programlisting>enable gdm.service
157	enable colord.service
158	enable accounts-daemon.service
159	enable avahi-daemon.*</programlisting>
160
161	</example>
162
163	<para>This enables the three mentioned units, plus all
164	<filename>avahi-daemon</filename> regardless of which
165	unit type. A file like this could be useful for
166	inclusion in a GNOME spin of a distribution. It will
167	ensure that the units necessary for GNOME are properly
168	enabled as they are installed. It leaves all other
169	units untouched, and subject to other (later) preset
170	files, for example like the one from the first example
171	above.</para>
172
173	<example>
174	<title>Administrator policy <filename>/etc/systemd/system-preset/00-lennart.preset</filename>:</title>
175
176	<programlisting>enable httpd.service
177	enable sshd.service
178	enable postfix.service
179	disable *</programlisting>
180	</example>
181
182	<para>This enables three specific services and
183	disables all others. This is useful for administrators
184	to specifically select the units to enable, and
185	disable all others. Due to the file name prefix
186	<literal>00-</literal> it will be read early and hence
187	overrides all other preset policy files.</para>
188	</refsect1>
189
190	<refsect1>
191	<title>See Also</title>
192	<para>
193	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
194	<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
195	<citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>
196	</para>
197	</refsect1>
198
199	</refentry>