<!--
SPDX-License-Identifier: LGPL-2.1+
-
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-->
<refentry id="systemd.service">
<refentryinfo>
<title>systemd.service</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
</refsect1>
<refsect1>
- <title>Implicit Dependencies</title>
-
- <para>The following dependencies are implicitly added:</para>
-
- <itemizedlist>
- <listitem><para>Services with <varname>Type=dbus</varname> set automatically
- acquire dependencies of type <varname>Requires=</varname> and
- <varname>After=</varname> on
- <filename>dbus.socket</filename>.</para></listitem>
-
- <listitem><para>Socket activated services are automatically ordered after
- their activating <filename>.socket</filename> units via an
- automatic <varname>After=</varname> dependency.
- Services also pull in all <filename>.socket</filename> units
- listed in <varname>Sockets=</varname> via automatic
- <varname>Wants=</varname> and <varname>After=</varname> dependencies.</para></listitem>
- </itemizedlist>
-
- <para>Additional implicit dependencies may be added as result of
- execution and resource control parameters as documented in
- <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- and
- <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ <title>Service Templates</title>
+
+ <para>It is possible for <command>systemd</command> services to take a single argument via the
+ <literal><replaceable>service</replaceable>@<replaceable>argument</replaceable>.service</literal>
+ syntax. Such services are called "instantiated" services, while the unit definition without the
+ <replaceable>argument</replaceable> parameter is called a "template". An example could be a
+ <filename>dhcpcd@.service</filename> service template which takes a network interface as a
+ parameter to form an instantiated service. Within the service file, this parameter or "instance
+ name" can be accessed with %-specifiers. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details.</para>
</refsect1>
<refsect1>
- <title>Default Dependencies</title>
-
- <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
-
- <itemizedlist>
- <listitem><para>Service units will have dependencies of type <varname>Requires=</varname> and
- <varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>After=</varname> on
- <filename>basic.target</filename> as well as dependencies of type <varname>Conflicts=</varname> and
- <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that normal service units pull in
- basic system initialization, and are terminated cleanly prior to system shutdown. Only services involved with early
- boot or late system shutdown should disable this option.</para></listitem>
-
- <listitem><para>Instanced service units (i.e. service units with an <literal>@</literal> in their name) are assigned by
- default a per-template slice unit (see
- <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>), named after the
- template unit, containing all instances of the specific template. This slice is normally stopped at shutdown,
- together with all template instances. If that is not desired, set <varname>DefaultDependencies=no</varname> in the
- template unit, and either define your own per-template slice unit file that also sets
- <varname>DefaultDependencies=no</varname>, or set <varname>Slice=system.slice</varname> (or another suitable slice)
- in the template unit. Also see
- <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
- </para></listitem>
- </itemizedlist>
+ <title>Automatic Dependencies</title>
+
+ <refsect2>
+ <title>Implicit Dependencies</title>
+
+ <para>The following dependencies are implicitly added:</para>
+
+ <itemizedlist>
+ <listitem><para>Services with <varname>Type=dbus</varname> set automatically
+ acquire dependencies of type <varname>Requires=</varname> and
+ <varname>After=</varname> on
+ <filename>dbus.socket</filename>.</para></listitem>
+
+ <listitem><para>Socket activated services are automatically ordered after
+ their activating <filename>.socket</filename> units via an
+ automatic <varname>After=</varname> dependency.
+ Services also pull in all <filename>.socket</filename> units
+ listed in <varname>Sockets=</varname> via automatic
+ <varname>Wants=</varname> and <varname>After=</varname> dependencies.</para></listitem>
+ </itemizedlist>
+
+ <para>Additional implicit dependencies may be added as result of
+ execution and resource control parameters as documented in
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ and
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>Default Dependencies</title>
+
+ <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
+
+ <itemizedlist>
+ <listitem><para>Service units will have dependencies of type <varname>Requires=</varname> and
+ <varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>After=</varname> on
+ <filename>basic.target</filename> as well as dependencies of type <varname>Conflicts=</varname> and
+ <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that normal service units pull in
+ basic system initialization, and are terminated cleanly prior to system shutdown. Only services involved with early
+ boot or late system shutdown should disable this option.</para></listitem>
+
+ <listitem><para>Instanced service units (i.e. service units with an <literal>@</literal> in their name) are assigned by
+ default a per-template slice unit (see
+ <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>), named after the
+ template unit, containing all instances of the specific template. This slice is normally stopped at shutdown,
+ together with all template instances. If that is not desired, set <varname>DefaultDependencies=no</varname> in the
+ template unit, and either define your own per-template slice unit file that also sets
+ <varname>DefaultDependencies=no</varname>, or set <varname>Slice=system.slice</varname> (or another suitable slice)
+ in the template unit. Also see
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para></listitem>
+ </itemizedlist>
+ </refsect2>
</refsect1>
<refsect1>
<row>
<entry><literal>!</literal></entry>
- <entry>Similar to the <literal>+</literal> character discussed above this permits invoking command lines with elevated privileges. However, unlike <literal>+</literal> the <literal>!</literal> character exclusively alters the effect of <varname>User=</varname>, <varname>Group=</varname> and <varname>SupplementaryGroups=</varname>, i.e. only the stanzas the affect user and group credentials. Note that this setting may be combined with <varname>DynamicUser=</varname>, in which case a dynamic user/group pair is allocated before the command is invoked, but credential changing is left to the executed process itself.</entry>
+ <entry>Similar to the <literal>+</literal> character discussed above this permits invoking command lines with elevated privileges. However, unlike <literal>+</literal> the <literal>!</literal> character exclusively alters the effect of <varname>User=</varname>, <varname>Group=</varname> and <varname>SupplementaryGroups=</varname>, i.e. only the stanzas that affect user and group credentials. Note that this setting may be combined with <varname>DynamicUser=</varname>, in which case a dynamic user/group pair is allocated before the command is invoked, but credential changing is left to the executed process itself.</entry>
</row>
<row>
must occur before <varname>RuntimeMaxSec=</varname> is exceeded, and once the runtime has exended beyond
<varname>RuntimeMaxSec=</varname>, the service manager will allow the service to continue to run, provided
the service repeats <literal>EXTEND_TIMEOUT_USEC=…</literal> within the interval specified until the service
- shutdown is acheived by <literal>STOPPING=1</literal> (or termination). (see
+ shutdown is achieved by <literal>STOPPING=1</literal> (or termination). (see
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>).
</para></listitem>
</varlistentry>
passed to the service manager from a specific service are passed back to the service's main process on the next
service restart. Any file descriptors passed to the service manager are automatically closed when
<constant>POLLHUP</constant> or <constant>POLLERR</constant> is seen on them, or when the service is fully
- stopped and no job is queued or being executed for it.</para></listitem>
+ stopped and no job is queued or being executed for it. If this option is used, <varname>NotifyAccess=</varname>
+ (see above) should be set to open access to the notification socket provided by systemd. If
+ <varname>NotifyAccess=</varname> is not set, it will be implicitly set to
+ <option>main</option>.</para></listitem>
</varlistentry>
<varlistentry>
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