+++ /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 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></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>/etc/systemd/user/*</filename>
-<filename>/run/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 file system path, or a timer controlled and
- supervised by
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. 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>.
- </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 is prefixed
- with <option>X-</option> it is ignored completely by
- systemd. 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 <filename>.conf</filename> 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>If a line starts with <option>.include</option>
- followed by a file name, the specified file will be
- parsed at this point. Make sure that the file that is
- included has the appropriate section headers before
- any directives.</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 name space. Example: a device unit
- <filename>dev-sda.device</filename> refers to a device
- with the device node <filename>/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 file name. 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
- filesystem. If that yields no success and the unit
- name contains an @ character, systemd will look for a
- unit template that shares the same name but with the
- instance string (i.e. the part between the @ 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 higher
- in the hierarchy override files with the same name
- lower in the hierarchy, thus allowing overrides.
- </para>
-
- <para>When systemd is running in session 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>/run/systemd/generator.early</filename></entry>
- <entry>Generated units</entry>
- </row>
- <row>
- <entry><filename>@SYSTEM_CONFIG_UNIT_PATH@</filename></entry>
- <entry morerows='1'>Local configuration</entry>
- </row>
- <row>
- <entry><filename>/etc/systemd/system</filename></entry>
- </row>
- <row>
- <entry><filename>/run/systemd/systemd</filename></entry>
- <entry>Volatile units</entry>
- </row>
- <row>
- <entry><filename>/run/systemd/generator</filename></entry>
- <entry>Generated units</entry>
- </row>
- <row>
- <entry><filename>/usr/local/lib/systemd/system</filename></entry>
- <entry>Units for local packages</entry>
- </row>
- <row>
- <entry><filename>@systemunitdir@</filename></entry>
- <entry>Systemd package configuration</entry>
- </row>
- <row>
- <entry><filename>/usr/lib/systemd/system</filename></entry>
- <entry morerows='1'>Units for installed packages</entry>
- </row>
- <row>
- <entry><filename>/lib/systemd/system</filename></entry>
- </row>
- <row>
- <entry><filename>/run/systemd/generator.late</filename></entry>
- <entry>Generated units</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
-
- <table>
- <title>
- Load path when running in session 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>/tmp/systemd-generator.early.<replaceable>XXXXXX</replaceable></filename></entry>
- <entry>Generated units</entry>
- </row>
- <row>
- <entry><filename>@USER_CONFIG_UNIT_PATH@</filename></entry>
- <entry morerows='1'>Local configuration</entry>
- </row>
- <row>
- <entry><filename>/etc/systemd/user</filename></entry>
- </row>
- <row>
- <entry><filename>/run/systemd/user</filename></entry>
- <entry>Volatile units</entry>
- </row>
- <row>
- <entry><filename>/tmp/systemd-generator.<replaceable>XXXXXX</replaceable></filename></entry>
- <entry>Generated units</entry>
- </row>
- <row>
- <entry><filename>/usr/local/lib/systemd/user</filename></entry>
- <entry morerows='1'>Units for local packages</entry>
- </row>
- <row>
- <entry><filename>/usr/local/share/systemd/user</filename></entry>
- </row>
- <row>
- <entry><filename>@userunitdir@</filename></entry>
- <entry>Systemd package configuration</entry>
- </row>
- <row>
- <entry><filename>/usr/lib/systemd/user</filename></entry>
- <entry morerows='1'>Units for installed packages</entry>
- </row>
- <row>
- <entry><filename>/usr/share/systemd/user</filename></entry>
- </row>
- <row>
- <entry><filename>/tmp/systemd-generator.late.<replaceable>XXXXXX</replaceable></filename></entry>
- <entry>Generated units</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
-
- <para>Note: the paths listed above are set at
- compilation time and differ between distributions. The
- "authorative" list is printed by
- <command>systemd</command> at during start and daemon
- reconfiguration.</para>
-
- <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>.
- </para>
- </refsect1>
-
- <refsect1>
- <title>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.</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><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, in which
- case requirement dependencies for all
- listed names are 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 a unit listed here is not started
- already it will not be started and the
- transaction fails
- immediately.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Wants=</varname></term>
-
- <listitem><para>A weaker version of
- <varname>Requires=</varname>. A unit
- listed in this option will be started
- if the configuring unit is. However,
- if the listed unit fails to start up
- 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 a symlink 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>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>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 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>Lists 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>Lists one or more
- units where reload requests on the
- unit will be propagated to/on the
- other unit will be propagated
- from. 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>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></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>OnFailureIsolate=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If <option>true</option> the
- unit listed in
- <varname>OnFailure=</varname> will be
- enqueued in isolation mode, i.e. all
- units that are not its dependency will
- be stopped. If this is set only a
- single unit may be listed in
- <varname>OnFailure=</varname>. Defaults
- to
- <option>false</option>.</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>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>ConditionKernelCommandLine=</varname></term>
- <term><varname>ConditionVirtualization=</varname></term>
- <term><varname>ConditionSecurity=</varname></term>
- <term><varname>ConditionCapability=</varname></term>
- <term><varname>ConditionHost=</varname></term>
- <term><varname>ConditionACPower=</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>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
- ('!'), 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>Similar,
- <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
- '='). 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>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>chroot</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>ConditionSecurity=</varname>
- may be used to check whether the given
- security module is enabled on the
- system. Currently the only recognized
- value is <varname>selinux</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><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>ConditionHost=</varname>
- may be used to match against the
- host name or machine ID of the
- host. This either takes a host name
- string (optionally with shell style
- globs) which is tested against the
- locally set host name 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>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>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. Thus
- functionality should not be used in
- normal units.</para></listitem>
- </varlistentry>
- </variablelist>
-
- <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>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 file name.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>WantedBy=</varname></term>
- <term><varname>RequiredBy=</varname></term>
-
- <listitem><para>Installs a symlink in
- the <filename>.wants/</filename>
- or <filename>.requires/</filename>
- subdirectory for a unit, respectively. This has the
- effect that when the listed unit name
- is activated the unit listing it is
- activated
- too. <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.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Also=</varname></term>
-
- <listitem><para>Additional units to
- install when this unit is
- installed. If the user requests
- installation of a unit with this
- option configured,
- <command>systemctl enable</command>
- will automatically install units
- listed in this option as
- well.</para></listitem>
- </varlistentry>
- </variablelist>
-
- <para>The following specifiers are interpreted in the
- Install section: %n, %N, %p, %i, %U, %u, %m, %H, %b.
- 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></entry>
- </row>
- <row>
- <entry><literal>%p</literal></entry>
- <entry>Prefix name</entry>
- <entry>For instantiated units this refers to the string before the @. For non-instantiated units this refers to 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></entry>
- </row>
- <row>
- <entry><literal>%i</literal></entry>
- <entry>Instance name</entry>
- <entry>For instantiated units: this is the string between the @ character and the suffix.</entry>
- </row>
- <row>
- <entry><literal>%I</literal></entry>
- <entry>Unescaped instance name</entry>
- <entry></entry>
- </row>
- <row>
- <entry><literal>%f</literal></entry>
- <entry>Unescaped file name</entry>
- <entry>This is either the unescaped instance name (if applicable) with / prepended (if applicable), or the prefix name similarly prepended with /.</entry>
- </row>
- <row>
- <entry><literal>%c</literal></entry>
- <entry>Control group path of the unit</entry>
- <entry></entry>
- </row>
- <row>
- <entry><literal>%r</literal></entry>
- <entry>Root control group path of systemd</entry>
- <entry></entry>
- </row>
- <row>
- <entry><literal>%R</literal></entry>
- <entry>Parent directory of the root control group path of systemd</entry>
- <entry></entry>
- </row>
- <row>
- <entry><literal>%t</literal></entry>
- <entry>Runtime socket dir</entry>
- <entry>This is either <filename>/run</filename> (for the system manager) or <literal>$XDG_RUNTIME_DIR</literal> (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 UID of the configured user of the unit, or (if none is set) the user running the systemd instance.</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 instance.</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 instance. If the user is
- <literal>root</literal> (UID equal to 0), the
- shell configured in account database is
- ignored and <filename>/bin/sh</filename> is
- always used.
- </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 host name of the running system.</entry>
- </row>
- <row>
- <entry><literal>%%</literal></entry>
- <entry>Escaped %</entry>
- <entry>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.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- </para>
- </refsect1>
-
-</refentry>
~ianmdlvl / elogind.git / blobdiff