mirror of
https://github.com/systemd/systemd.git
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1520 lines
87 KiB
XML
1520 lines
87 KiB
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" [
|
||
<!ENTITY % entities SYSTEM "custom-entities.ent" >
|
||
%entities;
|
||
]>
|
||
|
||
<!--
|
||
This file is part of systemd.
|
||
|
||
Copyright 2010 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.unit">
|
||
|
||
<refentryinfo>
|
||
<title>systemd.unit</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.unit</refentrytitle>
|
||
<manvolnum>5</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>systemd.unit</refname>
|
||
<refpurpose>Unit configuration</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<para><filename><replaceable>service</replaceable>.service</filename>,
|
||
<filename><replaceable>socket</replaceable>.socket</filename>,
|
||
<filename><replaceable>device</replaceable>.device</filename>,
|
||
<filename><replaceable>mount</replaceable>.mount</filename>,
|
||
<filename><replaceable>automount</replaceable>.automount</filename>,
|
||
<filename><replaceable>swap</replaceable>.swap</filename>,
|
||
<filename><replaceable>target</replaceable>.target</filename>,
|
||
<filename><replaceable>path</replaceable>.path</filename>,
|
||
<filename><replaceable>timer</replaceable>.timer</filename>,
|
||
<filename><replaceable>snapshot</replaceable>.snapshot</filename>,
|
||
<filename><replaceable>slice</replaceable>.slice</filename>,
|
||
<filename><replaceable>scope</replaceable>.scope</filename></para>
|
||
|
||
<para><literallayout><filename>/etc/systemd/system/*</filename>
|
||
<filename>/run/systemd/system/*</filename>
|
||
<filename>/usr/lib/systemd/system/*</filename>
|
||
<filename>...</filename>
|
||
</literallayout></para>
|
||
|
||
<para><literallayout><filename>$XDG_CONFIG_HOME/systemd/user/*</filename>
|
||
<filename>$HOME/.config/systemd/user/*</filename>
|
||
<filename>/etc/systemd/user/*</filename>
|
||
<filename>/run/systemd/user/*</filename>
|
||
<filename>$XDG_DATA_HOME/systemd/user/*</filename>
|
||
<filename>$HOME/.local/share/systemd/user/*</filename>
|
||
<filename>/usr/lib/systemd/user/*</filename>
|
||
<filename>...</filename>
|
||
</literallayout></para>
|
||
</refsynopsisdiv>
|
||
|
||
<refsect1>
|
||
<title>Description</title>
|
||
|
||
<para>A unit configuration file encodes information
|
||
about a service, a socket, a device, a mount point, an
|
||
automount point, a swap file or partition, a start-up
|
||
target, a watched file system path, a timer controlled
|
||
and supervised by
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||
a temporary system state snapshot, a resource
|
||
management slice or a group of externally created
|
||
processes. The syntax is inspired by <ulink
|
||
url="http://standards.freedesktop.org/desktop-entry-spec/latest/">XDG
|
||
Desktop Entry Specification</ulink>
|
||
<filename>.desktop</filename> files, which are in turn
|
||
inspired by Microsoft Windows
|
||
<filename>.ini</filename> files.</para>
|
||
|
||
<para>This man page lists the common configuration
|
||
options of all the unit types. These options need to
|
||
be configured in the [Unit] or [Install]
|
||
sections of the unit files.</para>
|
||
|
||
<para>In addition to the generic [Unit] and [Install]
|
||
sections described here, each unit may have a
|
||
type-specific section, e.g. [Service] for a service
|
||
unit. See the respective man pages for more
|
||
information:
|
||
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
</para>
|
||
|
||
<para>Various settings are allowed to be specified
|
||
more than once, in which case the interpretation
|
||
depends on the setting. Often, multiple settings form
|
||
a list, and setting to an empty value "resets", which
|
||
means that previous assignments are ignored. When this
|
||
is allowed, it is mentioned in the description of the
|
||
setting. Note that using multiple assignments to the
|
||
same value makes the unit file incompatible with
|
||
parsers for the XDG <filename>.desktop</filename> file
|
||
format.</para>
|
||
|
||
<para>Unit files are loaded from a set of paths
|
||
determined during compilation, described in the next section.
|
||
</para>
|
||
|
||
<para>Unit files may contain additional options on top
|
||
of those listed here. If systemd encounters an unknown
|
||
option, it will write a warning log message but
|
||
continue loading the unit. If an option or section name
|
||
is prefixed with <option>X-</option>, it is ignored
|
||
completely by systemd. Options within an ignored
|
||
section do not need the prefix. Applications may use
|
||
this to include additional information in the unit
|
||
files.</para>
|
||
|
||
<para>Boolean arguments used in unit files can be
|
||
written in various formats. For positive settings the
|
||
strings <option>1</option>, <option>yes</option>,
|
||
<option>true</option> and <option>on</option> are
|
||
equivalent. For negative settings, the strings
|
||
<option>0</option>, <option>no</option>,
|
||
<option>false</option> and <option>off</option> are
|
||
equivalent.</para>
|
||
|
||
<para>Time span values encoded in unit files can be
|
||
written in various formats. A stand-alone number
|
||
specifies a time in seconds. If suffixed with a time
|
||
unit, the unit is honored. A concatenation of multiple
|
||
values with units is supported, in which case the
|
||
values are added up. Example: "50" refers to 50
|
||
seconds; "2min 200ms" refers to 2 minutes plus 200
|
||
milliseconds, i.e. 120200ms. The following time units
|
||
are understood: s, min, h, d, w, ms, us. For details
|
||
see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
|
||
|
||
<para>Empty lines and lines starting with # or ; are
|
||
ignored. This may be used for commenting. Lines ending
|
||
in a backslash are concatenated with the following
|
||
line while reading and the backslash is replaced by a
|
||
space character. This may be used to wrap long lines.</para>
|
||
|
||
<para>Along with a unit file
|
||
<filename>foo.service</filename>, the directory
|
||
<filename>foo.service.wants/</filename> may exist. All
|
||
unit files symlinked from such a directory are
|
||
implicitly added as dependencies of type
|
||
<varname>Wanted=</varname> to the unit. This is useful
|
||
to hook units into the start-up of other units,
|
||
without having to modify their unit files. For details
|
||
about the semantics of <varname>Wanted=</varname>, see
|
||
below. The preferred way to create symlinks in the
|
||
<filename>.wants/</filename> directory of a unit file
|
||
is with the <command>enable</command> command of the
|
||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
tool which reads information from the [Install]
|
||
section of unit files (see below). A similar
|
||
functionality exists for <varname>Requires=</varname>
|
||
type dependencies as well, the directory suffix is
|
||
<filename>.requires/</filename> in this case.</para>
|
||
|
||
<para>Along with a unit file
|
||
<filename>foo.service</filename>, a directory
|
||
<filename>foo.service.d/</filename> may exist. All
|
||
files with the suffix <literal>.conf</literal> from
|
||
this directory will be parsed after the file itself is
|
||
parsed. This is useful to alter or add configuration
|
||
settings to a unit, without having to modify their
|
||
unit files. Make sure that the file that is included
|
||
has the appropriate section headers before any
|
||
directive.</para>
|
||
|
||
<para>Note that while systemd offers a flexible
|
||
dependency system between units it is recommended to
|
||
use this functionality only sparingly and instead rely
|
||
on techniques such as bus-based or socket-based
|
||
activation which make dependencies implicit, resulting
|
||
in a both simpler and more flexible system.</para>
|
||
|
||
<para>Some unit names reflect paths existing in the
|
||
file system namespace. Example: a device unit
|
||
<filename>dev-sda.device</filename> refers to a device
|
||
with the device node <filename noindex='true'>/dev/sda</filename> in
|
||
the file system namespace. If this applies, a special
|
||
way to escape the path name is used, so that the
|
||
result is usable as part of a filename. Basically,
|
||
given a path, "/" is replaced by "-", and all
|
||
unprintable characters and the "-" are replaced by
|
||
C-style "\x20" escapes. The root directory "/" is
|
||
encoded as single dash, while otherwise the initial
|
||
and ending "/" is removed from all paths during
|
||
transformation. This escaping is reversible.</para>
|
||
|
||
<para>Optionally, units may be instantiated from a
|
||
template file at runtime. This allows creation of
|
||
multiple units from a single configuration file. If
|
||
systemd looks for a unit configuration file, it will
|
||
first search for the literal unit name in the
|
||
file system. If that yields no success and the unit
|
||
name contains an <literal>@</literal> character, systemd will look for a
|
||
unit template that shares the same name but with the
|
||
instance string (i.e. the part between the <literal>@</literal> character
|
||
and the suffix) removed. Example: if a service
|
||
<filename>getty@tty3.service</filename> is requested
|
||
and no file by that name is found, systemd will look
|
||
for <filename>getty@.service</filename> and
|
||
instantiate a service from that configuration file if
|
||
it is found.</para>
|
||
|
||
<para>To refer to the instance string from
|
||
within the configuration file you may use the special
|
||
<literal>%i</literal> specifier in many of the
|
||
configuration options. See below for details.</para>
|
||
|
||
<para>If a unit file is empty (i.e. has the file size
|
||
0) or is symlinked to <filename>/dev/null</filename>,
|
||
its configuration will not be loaded and it appears
|
||
with a load state of <literal>masked</literal>, and
|
||
cannot be activated. Use this as an effective way to
|
||
fully disable a unit, making it impossible to start it
|
||
even manually.</para>
|
||
|
||
<para>The unit file format is covered by the
|
||
<ulink
|
||
url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface
|
||
Stability Promise</ulink>.</para>
|
||
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Unit Load Path</title>
|
||
|
||
<para>Unit files are loaded from a set of paths
|
||
determined during compilation, described in the two
|
||
tables below. Unit files found in directories listed
|
||
earlier override files with the same name in
|
||
directories lower in the list.</para>
|
||
|
||
<para>When systemd is running in user mode
|
||
(<option>--user</option>) and the variable
|
||
<varname>$SYSTEMD_UNIT_PATH</varname> is set, this
|
||
contents of this variable overrides the unit load
|
||
path.
|
||
</para>
|
||
|
||
<table>
|
||
<title>
|
||
Load path when running in system mode (<option>--system</option>).
|
||
</title>
|
||
|
||
<tgroup cols='2'>
|
||
<colspec colname='path' />
|
||
<colspec colname='expl' />
|
||
<thead>
|
||
<row>
|
||
<entry>Path</entry>
|
||
<entry>Description</entry>
|
||
</row>
|
||
</thead>
|
||
<tbody>
|
||
<row>
|
||
<entry><filename>/etc/systemd/system</filename></entry>
|
||
<entry>Local configuration</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>/run/systemd/system</filename></entry>
|
||
<entry>Runtime units</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>/usr/lib/systemd/system</filename></entry>
|
||
<entry>Units of installed packages</entry>
|
||
</row>
|
||
</tbody>
|
||
</tgroup>
|
||
</table>
|
||
|
||
<table>
|
||
<title>
|
||
Load path when running in user mode (<option>--user</option>).
|
||
</title>
|
||
|
||
<tgroup cols='2'>
|
||
<colspec colname='path' />
|
||
<colspec colname='expl' />
|
||
<thead>
|
||
<row>
|
||
<entry>Path</entry>
|
||
<entry>Description</entry>
|
||
</row>
|
||
</thead>
|
||
<tbody>
|
||
<row>
|
||
<entry><filename>$XDG_CONFIG_HOME/systemd/user</filename></entry>
|
||
<entry>User configuration (only used when $XDG_CONFIG_HOME is set)</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>$HOME/.config/systemd/user</filename></entry>
|
||
<entry>User configuration (only used when $XDG_CONFIG_HOME is not set)</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>/etc/systemd/user</filename></entry>
|
||
<entry>Local configuration</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>/run/systemd/user</filename></entry>
|
||
<entry>Runtime units</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>$XDG_DATA_HOME/systemd/user</filename></entry>
|
||
<entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is set)</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>$HOME/.local/share/systemd/user</filename></entry>
|
||
<entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is not set)</entry>
|
||
</row>
|
||
<row>
|
||
<entry><filename>/usr/lib/systemd/user</filename></entry>
|
||
<entry>Units of packages that have been installed system-wide</entry>
|
||
</row>
|
||
</tbody>
|
||
</tgroup>
|
||
</table>
|
||
|
||
<para>Additional units might be loaded into systemd
|
||
("linked") from directories not on the unit load
|
||
path. See the <command>link</command> command for
|
||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Also,
|
||
some units are dynamically created via generators
|
||
<ulink
|
||
url="http://www.freedesktop.org/wiki/Software/systemd/Generators/">Generators</ulink>.
|
||
</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>[Unit] Section Options</title>
|
||
|
||
<para>Unit file may include a [Unit] section, which
|
||
carries generic information about the unit that is not
|
||
dependent on the type of unit:</para>
|
||
|
||
<variablelist class='unit-directives'>
|
||
|
||
<varlistentry>
|
||
<term><varname>Description=</varname></term>
|
||
<listitem><para>A free-form string
|
||
describing the unit. This is intended
|
||
for use in UIs to show descriptive
|
||
information along with the unit
|
||
name. The description should contain a name
|
||
that means something to the end user.
|
||
<literal>Apache2 Web Server</literal> is a good
|
||
example. Bad examples are
|
||
<literal>high-performance light-weight HTTP
|
||
server</literal> (too generic) or
|
||
<literal>Apache2</literal> (too specific and
|
||
meaningless for people who do not know
|
||
Apache).</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Documentation=</varname></term>
|
||
<listitem><para>A space-separated list
|
||
of URIs referencing documentation for
|
||
this unit or its
|
||
configuration. Accepted are only URIs
|
||
of the types
|
||
<literal>http://</literal>,
|
||
<literal>https://</literal>,
|
||
<literal>file:</literal>,
|
||
<literal>info:</literal>,
|
||
<literal>man:</literal>. For more
|
||
information about the syntax of these
|
||
URIs, see
|
||
<citerefentry project='man-pages'><refentrytitle>uri</refentrytitle><manvolnum>7</manvolnum></citerefentry>. The
|
||
URIs should be listed in order of
|
||
relevance, starting with the most
|
||
relevant. It is a good idea to first
|
||
reference documentation that explains
|
||
what the unit's purpose is, followed
|
||
by how it is configured, followed by
|
||
any other related documentation. This
|
||
option may be specified more than once,
|
||
in which case the specified list of
|
||
URIs is merged. If the empty string is
|
||
assigned to this option, the list is
|
||
reset and all prior assignments will
|
||
have no effect.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Requires=</varname></term>
|
||
|
||
<listitem><para>Configures requirement
|
||
dependencies on other units. If this
|
||
unit gets activated, the units listed
|
||
here will be activated as well. If one
|
||
of the other units gets deactivated or
|
||
its activation fails, this unit will
|
||
be deactivated. This option may be
|
||
specified more than once or multiple
|
||
space-separated units may be specified
|
||
in one option in which case
|
||
requirement dependencies for all
|
||
listed names will be created. Note
|
||
that requirement dependencies do not
|
||
influence the order in which services
|
||
are started or stopped. This has to be
|
||
configured independently with the
|
||
<varname>After=</varname> or
|
||
<varname>Before=</varname> options. If
|
||
a unit
|
||
<filename>foo.service</filename>
|
||
requires a unit
|
||
<filename>bar.service</filename> as
|
||
configured with
|
||
<varname>Requires=</varname> and no
|
||
ordering is configured with
|
||
<varname>After=</varname> or
|
||
<varname>Before=</varname>, then both
|
||
units will be started simultaneously
|
||
and without any delay between them if
|
||
<filename>foo.service</filename> is
|
||
activated. Often it is a better choice
|
||
to use <varname>Wants=</varname>
|
||
instead of
|
||
<varname>Requires=</varname> in order
|
||
to achieve a system that is more
|
||
robust when dealing with failing
|
||
services.</para>
|
||
|
||
<para>Note that dependencies of this
|
||
type may also be configured outside of
|
||
the unit configuration file by
|
||
adding a symlink to a
|
||
<filename>.requires/</filename> directory
|
||
accompanying the unit file. For
|
||
details see above.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>RequiresOverridable=</varname></term>
|
||
|
||
<listitem><para>Similar to
|
||
<varname>Requires=</varname>.
|
||
Dependencies listed in
|
||
<varname>RequiresOverridable=</varname>
|
||
which cannot be fulfilled or fail to
|
||
start are ignored if the startup was
|
||
explicitly requested by the user. If
|
||
the start-up was pulled in indirectly
|
||
by some dependency or automatic
|
||
start-up of units that is not
|
||
requested by the user, this dependency
|
||
must be fulfilled and otherwise the
|
||
transaction fails. Hence, this option
|
||
may be used to configure dependencies
|
||
that are normally honored unless the
|
||
user explicitly starts up the unit, in
|
||
which case whether they failed or not
|
||
is irrelevant.</para></listitem>
|
||
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><varname>Requisite=</varname></term>
|
||
<term><varname>RequisiteOverridable=</varname></term>
|
||
|
||
<listitem><para>Similar to
|
||
<varname>Requires=</varname> and
|
||
<varname>RequiresOverridable=</varname>,
|
||
respectively. However, if the units
|
||
listed here are not started already,
|
||
they will not be started and the
|
||
transaction will fail immediately.
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Wants=</varname></term>
|
||
|
||
<listitem><para>A weaker version of
|
||
<varname>Requires=</varname>. Units
|
||
listed in this option will be started
|
||
if the configuring unit is. However,
|
||
if the listed units fail to start
|
||
or cannot be added to the transaction,
|
||
this has no impact on the validity of
|
||
the transaction as a whole. This is
|
||
the recommended way to hook start-up
|
||
of one unit to the start-up of another
|
||
unit.</para>
|
||
|
||
<para>Note that dependencies of this
|
||
type may also be configured outside of
|
||
the unit configuration file by adding
|
||
symlinks to a
|
||
<filename>.wants/</filename> directory
|
||
accompanying the unit file. For
|
||
details, see above.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>BindsTo=</varname></term>
|
||
|
||
<listitem><para>Configures requirement
|
||
dependencies, very similar in style to
|
||
<varname>Requires=</varname>, however
|
||
in addition to this behavior, it also
|
||
declares that this unit is stopped
|
||
when any of the units listed suddenly
|
||
disappears. Units can suddenly,
|
||
unexpectedly disappear if a service
|
||
terminates on its own choice, a device
|
||
is unplugged or a mount point
|
||
unmounted without involvement of
|
||
systemd.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>PartOf=</varname></term>
|
||
|
||
<listitem><para>Configures dependencies
|
||
similar to <varname>Requires=</varname>,
|
||
but limited to stopping and restarting
|
||
of units. When systemd stops or restarts
|
||
the units listed here, the action is
|
||
propagated to this unit.
|
||
Note that this is a one-way dependency —
|
||
changes to this unit do not affect the
|
||
listed units.
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Conflicts=</varname></term>
|
||
|
||
<listitem><para>A space-separated list
|
||
of unit names. Configures negative
|
||
requirement dependencies. If a unit
|
||
has a <varname>Conflicts=</varname>
|
||
setting on another unit, starting the
|
||
former will stop the latter and vice
|
||
versa. Note that this setting is
|
||
independent of and orthogonal to the
|
||
<varname>After=</varname> and
|
||
<varname>Before=</varname> ordering
|
||
dependencies.</para>
|
||
|
||
<para>If a unit A that conflicts with
|
||
a unit B is scheduled to be started at
|
||
the same time as B, the transaction
|
||
will either fail (in case both are
|
||
required part of the transaction) or
|
||
be modified to be fixed (in case one
|
||
or both jobs are not a required part
|
||
of the transaction). In the latter
|
||
case, the job that is not the required
|
||
will be removed, or in case both are
|
||
not required, the unit that conflicts
|
||
will be started and the unit that is
|
||
conflicted is
|
||
stopped.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Before=</varname></term>
|
||
<term><varname>After=</varname></term>
|
||
|
||
<listitem><para>A space-separated list
|
||
of unit names. Configures ordering
|
||
dependencies between units. If a unit
|
||
<filename>foo.service</filename>
|
||
contains a setting
|
||
<option>Before=bar.service</option>
|
||
and both units are being started,
|
||
<filename>bar.service</filename>'s
|
||
start-up is delayed until
|
||
<filename>foo.service</filename> is
|
||
started up. Note that this setting is
|
||
independent of and orthogonal to the
|
||
requirement dependencies as configured
|
||
by <varname>Requires=</varname>. It is
|
||
a common pattern to include a unit
|
||
name in both the
|
||
<varname>After=</varname> and
|
||
<varname>Requires=</varname> option, in
|
||
which case the unit listed will be
|
||
started before the unit that is
|
||
configured with these options. This
|
||
option may be specified more than
|
||
once, in which case ordering
|
||
dependencies for all listed names are
|
||
created. <varname>After=</varname> is
|
||
the inverse of
|
||
<varname>Before=</varname>, i.e. while
|
||
<varname>After=</varname> ensures that
|
||
the configured unit is started after
|
||
the listed unit finished starting up,
|
||
<varname>Before=</varname> ensures the
|
||
opposite, i.e. that the configured
|
||
unit is fully started up before the
|
||
listed unit is started. Note that when
|
||
two units with an ordering dependency
|
||
between them are shut down, the
|
||
inverse of the start-up order is
|
||
applied. i.e. if a unit is configured
|
||
with <varname>After=</varname> on
|
||
another unit, the former is stopped
|
||
before the latter if both are shut
|
||
down. If one unit with an ordering
|
||
dependency on another unit is shut
|
||
down while the latter is started up,
|
||
the shut down is ordered before the
|
||
start-up regardless of whether the
|
||
ordering dependency is actually of
|
||
type <varname>After=</varname> or
|
||
<varname>Before=</varname>. If two
|
||
units have no ordering dependencies
|
||
between them, they are shut down or
|
||
started up simultaneously, and no
|
||
ordering takes
|
||
place. </para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>OnFailure=</varname></term>
|
||
|
||
<listitem><para>A space-separated list
|
||
of one or more units that are
|
||
activated when this unit enters the
|
||
<literal>failed</literal>
|
||
state.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>PropagatesReloadTo=</varname></term>
|
||
<term><varname>ReloadPropagatedFrom=</varname></term>
|
||
|
||
<listitem><para>A space-separated list
|
||
of one or more units where reload
|
||
requests on this unit will be
|
||
propagated to, or reload requests on
|
||
the other unit will be propagated to
|
||
this unit, respectively. Issuing a
|
||
reload request on a unit will
|
||
automatically also enqueue a reload
|
||
request on all units that the reload
|
||
request shall be propagated to via
|
||
these two settings.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>JoinsNamespaceOf=</varname></term>
|
||
|
||
<listitem><para>For units that start
|
||
processes (such as service units),
|
||
lists one or more other units whose
|
||
network and/or temporary file
|
||
namespace to join. This only applies
|
||
to unit types which support the
|
||
<varname>PrivateNetwork=</varname> and
|
||
<varname>PrivateTmp=</varname>
|
||
directives (see
|
||
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
for details). If a unit that has this
|
||
setting set is started, its processes
|
||
will see the same
|
||
<filename>/tmp</filename>,
|
||
<filename>/tmp/var</filename> and
|
||
network namespace as one listed unit
|
||
that is started. If multiple listed
|
||
units are already started, it is not
|
||
defined which namespace is
|
||
joined. Note that this setting only
|
||
has an effect if
|
||
<varname>PrivateNetwork=</varname>
|
||
and/or <varname>PrivateTmp=</varname>
|
||
is enabled for both the unit that
|
||
joins the namespace and the unit whose
|
||
namespace is joined.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>RequiresMountsFor=</varname></term>
|
||
|
||
<listitem><para>Takes a
|
||
space-separated list of absolute
|
||
paths. Automatically adds dependencies
|
||
of type <varname>Requires=</varname>
|
||
and <varname>After=</varname> for all
|
||
mount units required to access the
|
||
specified path.</para>
|
||
|
||
<para>Mount points marked with
|
||
<option>noauto</option> are not
|
||
mounted automatically and will be
|
||
ignored for the purposes of this
|
||
option. If such a mount should be a
|
||
requirement for this unit,
|
||
direct dependencies on the mount
|
||
units may be added
|
||
(<varname>Requires=</varname> and
|
||
<varname>After=</varname> or
|
||
some other combination).
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>OnFailureJobMode=</varname></term>
|
||
|
||
<listitem><para>Takes a value of
|
||
<literal>fail</literal>,
|
||
<literal>replace</literal>,
|
||
<literal>replace-irreversibly</literal>,
|
||
<literal>isolate</literal>,
|
||
<literal>flush</literal>,
|
||
<literal>ignore-dependencies</literal>
|
||
or
|
||
<literal>ignore-requirements</literal>. Defaults
|
||
to
|
||
<literal>replace</literal>. Specifies
|
||
how the units listed in
|
||
<varname>OnFailure=</varname> will be
|
||
enqueued. See
|
||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
|
||
<option>--job-mode=</option> option
|
||
for details on the possible values. If
|
||
this is set to
|
||
<literal>isolate</literal>, only a
|
||
single unit may be listed in
|
||
<varname>OnFailure=</varname>..</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IgnoreOnIsolate=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
this unit will not be stopped when
|
||
isolating another unit. Defaults to
|
||
<option>false</option>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IgnoreOnSnapshot=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
this unit will not be included in
|
||
snapshots. Defaults to
|
||
<option>true</option> for device and
|
||
snapshot units, <option>false</option>
|
||
for the others.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>StopWhenUnneeded=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
this unit will be stopped when it is
|
||
no longer used. Note that in order to
|
||
minimize the work to be executed,
|
||
systemd will not stop units by default
|
||
unless they are conflicting with other
|
||
units, or the user explicitly
|
||
requested their shut down. If this
|
||
option is set, a unit will be
|
||
automatically cleaned up if no other
|
||
active unit requires it. Defaults to
|
||
<option>false</option>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>RefuseManualStart=</varname></term>
|
||
<term><varname>RefuseManualStop=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
this unit can only be activated
|
||
or deactivated indirectly. In
|
||
this case, explicit start-up
|
||
or termination requested by the
|
||
user is denied, however if it is
|
||
started or stopped as a
|
||
dependency of another unit, start-up
|
||
or termination will succeed. This
|
||
is mostly a safety feature to ensure
|
||
that the user does not accidentally
|
||
activate units that are not intended
|
||
to be activated explicitly, and not
|
||
accidentally deactivate units that are
|
||
not intended to be deactivated.
|
||
These options default to
|
||
<option>false</option>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>AllowIsolate=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
this unit may be used with the
|
||
<command>systemctl isolate</command>
|
||
command. Otherwise, this will be
|
||
refused. It probably is a good idea to
|
||
leave this disabled except for target
|
||
units that shall be used similar to
|
||
runlevels in SysV init systems, just
|
||
as a precaution to avoid unusable
|
||
system states. This option defaults to
|
||
<option>false</option>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>DefaultDependencies=</varname></term>
|
||
|
||
<listitem><para>Takes a boolean
|
||
argument. If <option>true</option>,
|
||
(the default), a few default
|
||
dependencies will implicitly be
|
||
created for the unit. The actual
|
||
dependencies created depend on the
|
||
unit type. For example, for service
|
||
units, these dependencies ensure that
|
||
the service is started only after
|
||
basic system initialization is
|
||
completed and is properly terminated on
|
||
system shutdown. See the respective
|
||
man pages for details. Generally, only
|
||
services involved with early boot or
|
||
late shutdown should set this option
|
||
to <option>false</option>. It is
|
||
highly recommended to leave this
|
||
option enabled for the majority of
|
||
common units. If set to
|
||
<option>false</option>, this option
|
||
does not disable all implicit
|
||
dependencies, just non-essential
|
||
ones.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>JobTimeoutSec=</varname></term>
|
||
|
||
<listitem><para>When clients are
|
||
waiting for a job of this unit to
|
||
complete, time out after the specified
|
||
time. If this time limit is reached,
|
||
the job will be cancelled, the unit
|
||
however will not change state or even
|
||
enter the <literal>failed</literal>
|
||
mode. This value defaults to 0 (job
|
||
timeouts disabled), except for device
|
||
units. NB: this timeout is independent
|
||
from any unit-specific timeout (for
|
||
example, the timeout set with
|
||
<varname>Timeout=</varname> in service
|
||
units) as the job timeout has no
|
||
effect on the unit itself, only on the
|
||
job that might be pending for it. Or
|
||
in other words: unit-specific timeouts
|
||
are useful to abort unit state
|
||
changes, and revert them. The job
|
||
timeout set with this option however
|
||
is useful to abort only the job
|
||
waiting for the unit state to
|
||
change.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>ConditionArchitecture=</varname></term>
|
||
<term><varname>ConditionVirtualization=</varname></term>
|
||
<term><varname>ConditionHost=</varname></term>
|
||
<term><varname>ConditionKernelCommandLine=</varname></term>
|
||
<term><varname>ConditionSecurity=</varname></term>
|
||
<term><varname>ConditionCapability=</varname></term>
|
||
<term><varname>ConditionACPower=</varname></term>
|
||
<term><varname>ConditionNeedsUpdate=</varname></term>
|
||
<term><varname>ConditionFirstBoot=</varname></term>
|
||
<term><varname>ConditionPathExists=</varname></term>
|
||
<term><varname>ConditionPathExistsGlob=</varname></term>
|
||
<term><varname>ConditionPathIsDirectory=</varname></term>
|
||
<term><varname>ConditionPathIsSymbolicLink=</varname></term>
|
||
<term><varname>ConditionPathIsMountPoint=</varname></term>
|
||
<term><varname>ConditionPathIsReadWrite=</varname></term>
|
||
<term><varname>ConditionDirectoryNotEmpty=</varname></term>
|
||
<term><varname>ConditionFileNotEmpty=</varname></term>
|
||
<term><varname>ConditionFileIsExecutable=</varname></term>
|
||
<term><varname>ConditionNull=</varname></term>
|
||
|
||
<listitem><para>Before starting a unit
|
||
verify that the specified condition is
|
||
true. If it is not true, the starting
|
||
of the unit will be skipped, however
|
||
all ordering dependencies of it are
|
||
still respected. A failing condition
|
||
will not result in the unit being
|
||
moved into a failure state. The
|
||
condition is checked at the time the
|
||
queued start job is to be
|
||
executed.</para>
|
||
|
||
<para><varname>ConditionArchitecture=</varname>
|
||
may be used to check whether the
|
||
system is running on a specific
|
||
architecture. Takes one of
|
||
<varname>x86</varname>,
|
||
<varname>x86-64</varname>,
|
||
<varname>ppc</varname>,
|
||
<varname>ppc-le</varname>,
|
||
<varname>ppc64</varname>,
|
||
<varname>ppc64-le</varname>,
|
||
<varname>ia64</varname>,
|
||
<varname>parisc</varname>,
|
||
<varname>parisc64</varname>,
|
||
<varname>s390</varname>,
|
||
<varname>s390x</varname>,
|
||
<varname>sparc</varname>,
|
||
<varname>sparc64</varname>,
|
||
<varname>mips</varname>,
|
||
<varname>mips-le</varname>,
|
||
<varname>mips64</varname>,
|
||
<varname>mips64-le</varname>,
|
||
<varname>alpha</varname>,
|
||
<varname>arm</varname>,
|
||
<varname>arm-be</varname>,
|
||
<varname>arm64</varname>,
|
||
<varname>arm64-be</varname>,
|
||
<varname>sh</varname>,
|
||
<varname>sh64</varname>,
|
||
<varname>m86k</varname>,
|
||
<varname>tilegx</varname>,
|
||
<varname>cris</varname> to test
|
||
against a specific architecture. The
|
||
architecture is determined from the
|
||
information returned by
|
||
<citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
|
||
and is thus subject to
|
||
<citerefentry><refentrytitle>personality</refentrytitle><manvolnum>2</manvolnum></citerefentry>. Note
|
||
that a <varname>Personality=</varname>
|
||
setting in the same unit file has no
|
||
effect on this condition. A special
|
||
architecture name
|
||
<varname>native</varname> is mapped to
|
||
the architecture the system manager
|
||
itself is compiled for. The test may
|
||
be negated by prepending an
|
||
exclamation mark.</para>
|
||
|
||
<para><varname>ConditionVirtualization=</varname>
|
||
may be used to check whether the
|
||
system is executed in a virtualized
|
||
environment and optionally test
|
||
whether it is a specific
|
||
implementation. Takes either boolean
|
||
value to check if being executed in
|
||
any virtualized environment, or one of
|
||
<varname>vm</varname> and
|
||
<varname>container</varname> to test
|
||
against a generic type of
|
||
virtualization solution, or one of
|
||
<varname>qemu</varname>,
|
||
<varname>kvm</varname>,
|
||
<varname>vmware</varname>,
|
||
<varname>microsoft</varname>,
|
||
<varname>oracle</varname>,
|
||
<varname>xen</varname>,
|
||
<varname>bochs</varname>,
|
||
<varname>uml</varname>,
|
||
<varname>openvz</varname>,
|
||
<varname>lxc</varname>,
|
||
<varname>lxc-libvirt</varname>,
|
||
<varname>systemd-nspawn</varname> to
|
||
test against a specific
|
||
implementation. If multiple
|
||
virtualization technologies are nested,
|
||
only the innermost is considered. The
|
||
test may be negated by prepending an
|
||
exclamation mark.</para>
|
||
|
||
<para><varname>ConditionHost=</varname>
|
||
may be used to match against the
|
||
hostname or machine ID of the
|
||
host. This either takes a hostname
|
||
string (optionally with shell style
|
||
globs) which is tested against the
|
||
locally set hostname as returned by
|
||
<citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
|
||
or a machine ID formatted as string
|
||
(see
|
||
<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
|
||
The test may be negated by prepending
|
||
an exclamation mark.</para>
|
||
|
||
<para><varname>ConditionKernelCommandLine=</varname>
|
||
may be used to check whether a
|
||
specific kernel command line option is
|
||
set (or if prefixed with the
|
||
exclamation mark unset). The argument
|
||
must either be a single word, or an
|
||
assignment (i.e. two words, separated
|
||
<literal>=</literal>). In the former
|
||
case the kernel command line is
|
||
searched for the word appearing as is,
|
||
or as left hand side of an
|
||
assignment. In the latter case, the
|
||
exact assignment is looked for with
|
||
right and left hand side
|
||
matching.</para>
|
||
|
||
<para><varname>ConditionSecurity=</varname>
|
||
may be used to check whether the given
|
||
security module is enabled on the
|
||
system. Currently the recognized values
|
||
values are <varname>selinux</varname>,
|
||
<varname>apparmor</varname>,
|
||
<varname>ima</varname> and
|
||
<varname>smack</varname>.
|
||
The test may be negated by prepending
|
||
an exclamation
|
||
mark.</para>
|
||
|
||
<para><varname>ConditionCapability=</varname>
|
||
may be used to check whether the given
|
||
capability exists in the capability
|
||
bounding set of the service manager
|
||
(i.e. this does not check whether
|
||
capability is actually available in
|
||
the permitted or effective sets, see
|
||
<citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||
for details). Pass a capability name
|
||
such as <literal>CAP_MKNOD</literal>,
|
||
possibly prefixed with an exclamation
|
||
mark to negate the check.</para>
|
||
|
||
<para><varname>ConditionACPower=</varname>
|
||
may be used to check whether the
|
||
system has AC power, or is exclusively
|
||
battery powered at the time of
|
||
activation of the unit. This takes a
|
||
boolean argument. If set to
|
||
<varname>true</varname>, the condition
|
||
will hold only if at least one AC
|
||
connector of the system is connected
|
||
to a power source, or if no AC
|
||
connectors are known. Conversely, if
|
||
set to <varname>false</varname>, the
|
||
condition will hold only if there is
|
||
at least one AC connector known and
|
||
all AC connectors are disconnected
|
||
from a power source.</para>
|
||
|
||
<para><varname>ConditionNeedsUpdate=</varname>
|
||
takes one of <filename>/var</filename>
|
||
or <filename>/etc</filename> as
|
||
argument, possibly prefixed with a
|
||
<literal>!</literal> (for inverting
|
||
the condition). This condition may be
|
||
used to conditionalize units on
|
||
whether the specified directory
|
||
requires an update because
|
||
<filename>/usr</filename>'s
|
||
modification time is newer than the
|
||
stamp file
|
||
<filename>.updated</filename> in the
|
||
specified directory. This is useful to
|
||
implement offline updates of the
|
||
vendor operating system resources in
|
||
<filename>/usr</filename> that require
|
||
updating of <filename>/etc</filename>
|
||
or <filename>/var</filename> on the
|
||
next following boot. Units making use
|
||
of this condition should order
|
||
themselves before
|
||
<citerefentry><refentrytitle>systemd-update-done.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||
to make sure they run before the stamp
|
||
files's modification time gets reset
|
||
indicating a completed update.</para>
|
||
|
||
<para><varname>ConditionFirstBoot=</varname>
|
||
takes a boolean argument. This
|
||
condition may be used to
|
||
conditionalize units on whether the
|
||
system is booting up with an
|
||
unpopulated <filename>/etc</filename>
|
||
directory. This may be used to
|
||
populate <filename>/etc</filename> on
|
||
the first boot after factory reset, or
|
||
when a new system instances boots up
|
||
for the first time.</para>
|
||
|
||
<para>With
|
||
<varname>ConditionPathExists=</varname>
|
||
a file existence condition is
|
||
checked before a unit is started. If
|
||
the specified absolute path name does
|
||
not exist, the condition will
|
||
fail. If the absolute path name passed
|
||
to
|
||
<varname>ConditionPathExists=</varname>
|
||
is prefixed with an exclamation mark
|
||
(<literal>!</literal>), the test is negated, and the unit
|
||
is only started if the path does not
|
||
exist.</para>
|
||
|
||
<para><varname>ConditionPathExistsGlob=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>,
|
||
but checks for the existence of at
|
||
least one file or directory matching
|
||
the specified globbing pattern.</para>
|
||
|
||
<para><varname>ConditionPathIsDirectory=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists and is a
|
||
directory.</para>
|
||
|
||
<para><varname>ConditionPathIsSymbolicLink=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists and is a symbolic
|
||
link.</para>
|
||
|
||
<para><varname>ConditionPathIsMountPoint=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists and is a mount
|
||
point.</para>
|
||
|
||
<para><varname>ConditionPathIsReadWrite=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether the underlying
|
||
file system is readable and writable
|
||
(i.e. not mounted
|
||
read-only).</para>
|
||
|
||
<para><varname>ConditionDirectoryNotEmpty=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists and is a non-empty
|
||
directory.</para>
|
||
|
||
<para><varname>ConditionFileNotEmpty=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists and refers to a regular file
|
||
with a non-zero size.</para>
|
||
|
||
<para><varname>ConditionFileIsExecutable=</varname>
|
||
is similar to
|
||
<varname>ConditionPathExists=</varname>
|
||
but verifies whether a certain path
|
||
exists, is a regular file and marked
|
||
executable.</para>
|
||
|
||
<para>Finally,
|
||
<varname>ConditionNull=</varname> may
|
||
be used to add a constant condition
|
||
check value to the unit. It takes a
|
||
boolean argument. If set to
|
||
<varname>false</varname>, the condition
|
||
will always fail, otherwise
|
||
succeed.</para>
|
||
|
||
<para>If multiple conditions are
|
||
specified, the unit will be executed if
|
||
all of them apply (i.e. a logical AND
|
||
is applied). Condition checks can be
|
||
prefixed with a pipe symbol (|) in
|
||
which case a condition becomes a
|
||
triggering condition. If at least one
|
||
triggering condition is defined for a
|
||
unit, then the unit will be executed if
|
||
at least one of the triggering
|
||
conditions apply and all of the
|
||
non-triggering conditions. If you
|
||
prefix an argument with the pipe
|
||
symbol and an exclamation mark, the
|
||
pipe symbol must be passed first, the
|
||
exclamation second. Except for
|
||
<varname>ConditionPathIsSymbolicLink=</varname>,
|
||
all path checks follow symlinks. If
|
||
any of these options is assigned the
|
||
empty string, the list of conditions is
|
||
reset completely, all previous
|
||
condition settings (of any kind) will
|
||
have no effect.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>SourcePath=</varname></term>
|
||
<listitem><para>A path to a
|
||
configuration file this unit has been
|
||
generated from. This is primarily
|
||
useful for implementation of generator
|
||
tools that convert configuration from
|
||
an external configuration file format
|
||
into native unit files. This
|
||
functionality should not be used in
|
||
normal units.</para></listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>[Install] Section Options</title>
|
||
|
||
<para>Unit file may include a [Install] section, which
|
||
carries installation information for the unit. This
|
||
section is not interpreted by
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
during runtime. It is used exclusively by the
|
||
<command>enable</command> and
|
||
<command>disable</command> commands of the
|
||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
tool during installation of a unit:</para>
|
||
|
||
<variablelist class='unit-directives'>
|
||
<varlistentry>
|
||
<term><varname>Alias=</varname></term>
|
||
|
||
<listitem><para>A space-seperated list
|
||
of additional names this unit shall be
|
||
installed under. The names listed here
|
||
must have the same suffix (i.e. type)
|
||
as the unit file name. This option may
|
||
be specified more than once, in which
|
||
case all listed names are used. At
|
||
installation time, <command>systemctl
|
||
enable</command> will create symlinks
|
||
from these names to the unit
|
||
filename.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>WantedBy=</varname></term>
|
||
<term><varname>RequiredBy=</varname></term>
|
||
|
||
<listitem><para>This option may be
|
||
used more than once, or a
|
||
space-separated list of unit names may
|
||
be given. A symbolic link is created
|
||
in the <filename>.wants/</filename> or
|
||
<filename>.requires/</filename>
|
||
directory of each of the listed units
|
||
when this unit is installed by
|
||
<command>systemctl enable</command>.
|
||
This has the effect that a dependency
|
||
of type <varname>Wants=</varname> or
|
||
<varname>Requires=</varname> is added
|
||
from the listed unit to the current
|
||
unit. The primary result is that the
|
||
current unit will be started when the
|
||
listed unit is started. See the
|
||
description of
|
||
<varname>Wants=</varname> and
|
||
<varname>Requires=</varname> in the
|
||
[Unit] section for details.</para>
|
||
|
||
<para><command>WantedBy=foo.service</command>
|
||
in a service
|
||
<filename>bar.service</filename> is
|
||
mostly equivalent to
|
||
<command>Alias=foo.service.wants/bar.service</command>
|
||
in the same file. In case of template
|
||
units, <command>systemctl enable</command>
|
||
must be called with an instance name, and
|
||
this instance will be added to the
|
||
<filename>.wants/</filename> or
|
||
<filename>.requires/</filename> list
|
||
of the listed unit.
|
||
E.g. <command>WantedBy=getty.target</command>
|
||
in a service
|
||
<filename>getty@.service</filename>
|
||
will result in <command>systemctl
|
||
enable getty@tty2.service</command>
|
||
creating a
|
||
<filename>getty.target.wants/getty@tty2.service</filename>
|
||
link to <filename>getty@.service</filename>.
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Also=</varname></term>
|
||
|
||
<listitem><para>Additional units to
|
||
install/deinstall when this unit is
|
||
installed/deinstalled. If the user
|
||
requests installation/deinstallation
|
||
of a unit with this option configured,
|
||
<command>systemctl enable</command>
|
||
and <command>systemctl
|
||
disable</command> will automatically
|
||
install/uninstall units listed in this option as
|
||
well.</para>
|
||
|
||
<para>This option may be used more
|
||
than once, or a space-separated list
|
||
of unit names may be
|
||
given.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>DefaultInstance=</varname></term>
|
||
|
||
<listitem><para>In template unit files,
|
||
this specifies for which instance the
|
||
unit shall be enabled if the template
|
||
is enabled without any explicitly set
|
||
instance. This option has no effect in
|
||
non-template unit files. The specified
|
||
string must be usable as instance
|
||
identifier.</para></listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
|
||
<para>The following specifiers are interpreted in the
|
||
Install section: %n, %N, %p, %i, %U, %u, %m, %H, %b, %v.
|
||
For their meaning see the next section.
|
||
</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Specifiers</title>
|
||
|
||
<para>Many settings resolve specifiers which may be
|
||
used to write generic unit files referring to runtime
|
||
or unit parameters that are replaced when the unit
|
||
files are loaded. The following specifiers are
|
||
understood:</para>
|
||
|
||
<table>
|
||
<title>Specifiers available in unit files</title>
|
||
<tgroup cols='3' align='left' colsep='1' rowsep='1'>
|
||
<colspec colname="spec" />
|
||
<colspec colname="mean" />
|
||
<colspec colname="detail" />
|
||
<thead>
|
||
<row>
|
||
<entry>Specifier</entry>
|
||
<entry>Meaning</entry>
|
||
<entry>Details</entry>
|
||
</row>
|
||
</thead>
|
||
<tbody>
|
||
<row>
|
||
<entry><literal>%n</literal></entry>
|
||
<entry>Full unit name</entry>
|
||
<entry></entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%N</literal></entry>
|
||
<entry>Unescaped full unit name</entry>
|
||
<entry>Same as <literal>%n</literal>, but with escaping undone</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%p</literal></entry>
|
||
<entry>Prefix name</entry>
|
||
<entry>For instantiated units, this refers to the string before the <literal>@</literal> character of the unit name. For non-instantiated units, this refers to the name of the unit with the type suffix removed.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%P</literal></entry>
|
||
<entry>Unescaped prefix name</entry>
|
||
<entry>Same as <literal>%p</literal>, but with escaping undone</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%i</literal></entry>
|
||
<entry>Instance name</entry>
|
||
<entry>For instantiated units: this is the string between the <literal>@</literal> character and the suffix of the unit name.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%I</literal></entry>
|
||
<entry>Unescaped instance name</entry>
|
||
<entry>Same as <literal>%i</literal>, but with escaping undone</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%f</literal></entry>
|
||
<entry>Unescaped filename</entry>
|
||
<entry>This is either the unescaped instance name (if applicable) with <filename>/</filename> prepended (if applicable), or the prefix name prepended with <filename>/</filename>.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%c</literal></entry>
|
||
<entry>Control group path of the unit</entry>
|
||
<entry>This path does not include the <filename>/sys/fs/cgroup/systemd/</filename> prefix.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%r</literal></entry>
|
||
<entry>Control group path of the slice the unit is placed in</entry>
|
||
<entry>This usually maps to the parent cgroup path of <literal>%c</literal>.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%R</literal></entry>
|
||
<entry>Root control group path below which slices and units are placed</entry>
|
||
<entry>For system instances, this resolves to <filename>/</filename>, except in containers, where this maps to the container's root control group path.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%t</literal></entry>
|
||
<entry>Runtime directory</entry>
|
||
<entry>This is either <filename>/run</filename> (for the system manager) or the path <literal>$XDG_RUNTIME_DIR</literal> resolves to (for user managers).</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%u</literal></entry>
|
||
<entry>User name</entry>
|
||
<entry>This is the name of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%U</literal></entry>
|
||
<entry>User UID</entry>
|
||
<entry>This is the numeric UID of the configured user of the unit, or (if none is set) the user running the systemd user instance. Note that this specifier is not available for units run by the systemd system instance (as opposed to those run by a systemd user instance), unless the user has been configured as a numeric UID in the first place or the configured user is the root user.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%h</literal></entry>
|
||
<entry>User home directory</entry>
|
||
<entry>This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd user instance. Similar to <literal>%U</literal>, this specifier is not available for units run by the systemd system instance, unless the configured user is the root user.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%s</literal></entry>
|
||
<entry>User shell</entry>
|
||
<entry>This is the shell of the configured user of the unit, or (if none is set) the user running the systemd user instance. Similar to <literal>%U</literal>, this specifier is not available for units run by the systemd system instance, unless the configured user is the root user.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%m</literal></entry>
|
||
<entry>Machine ID</entry>
|
||
<entry>The machine ID of the running system, formatted as string. See <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%b</literal></entry>
|
||
<entry>Boot ID</entry>
|
||
<entry>The boot ID of the running system, formatted as string. See <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%H</literal></entry>
|
||
<entry>Host name</entry>
|
||
<entry>The hostname of the running system at the point in time the unit configuation is loaded.</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%v</literal></entry>
|
||
<entry>Kernel release</entry>
|
||
<entry>Identical to <command>uname -r</command> output</entry>
|
||
</row>
|
||
<row>
|
||
<entry><literal>%%</literal></entry>
|
||
<entry>Single percent sign</entry>
|
||
<entry>Use <literal>%%</literal> in place of <literal>%</literal> to specify a single percent sign.</entry>
|
||
</row>
|
||
</tbody>
|
||
</tgroup>
|
||
</table>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para>
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
<citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>uname</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|