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man: document automatic dependencies For all units ensure there's an "Automatic Dependencies" section in the man page, and explain which dependencies are automatically added in all cases, and which ones are added on top if DefaultDependencies=yes is set. This is also done for systemd.exec(5), systemd.resource-control(5) and systemd.unit(5) as these pages describe common behaviour of various unit types.
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<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
man: add some initial man page work
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
Reindent man pages to 2ch
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
build-sys,man: use XML entities to substite strings This makes it easier to add substitutions to man pages, avoiding the separate transformation step. mkdir -p's are removed from the rule, because xsltproc will will create directories on it's own. All in all, two or three forks per man page are avoided, which should make things marginally faster. Unfortunately python parsers must too be tweaked to handle entities. This isn't particularly easy: with lxml a custom Resolver can be used, but the stdlib etree doesn't support external entities *at all*. So when running without lxml, the entities are just removed. Right now it doesn't matter, since the entities are not indexed anyway. But I intend to add indexing of filenames in the near future, and then the index generated without lxml might be missing a few lines. Oh well.
2013-03-30 02:22:27 +08:00
<!ENTITY % entities SYSTEM "custom-entities.ent" >
%entities;
]>
man: add some initial man page work
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<!--
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
relicense to LGPLv2.1 (with exceptions) We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.
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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
man: add some initial man page work
2010-05-16 05:06:41 +08:00
(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
relicense to LGPLv2.1 (with exceptions) We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.
2012-04-12 06:20:58 +08:00
Lesser General Public License for more details.
man: add some initial man page work
2010-05-16 05:06:41 +08:00
relicense to LGPLv2.1 (with exceptions) We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.
2012-04-12 06:20:58 +08:00
You should have received a copy of the GNU Lesser General Public License
man: add some initial man page work
2010-05-16 05:06:41 +08:00
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="systemd.unit">
Reindent man pages to 2ch
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<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>slice</replaceable>.slice</filename>,
<filename><replaceable>scope</replaceable>.scope</filename></para>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<para><literallayout><filename>/etc/systemd/system/*</filename>
man: describe unit load path in systemd.unit(5) In other cases where multiple directories are searched for unit files, the list of directories is described in the man page describing the format. I think this makes sense too in case of systemd directories, since the systemd(1) manpage already has an overview of many different topics.
2013-02-04 11:23:53 +08:00
<filename>/run/systemd/system/*</filename>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<filename>/usr/lib/systemd/system/*</filename>
man: shorten the list of unit file paths a bit Let's make this more digestable to read by making the list of documented unit file paths a bit shorter. Specifically, let's drop references to $XDG_CONFIG_HOME and $XDG_DATA_HOME, as their default values are listed too already. Given that the fact that the XDG basedir spec makes these paths configurable is probably not a strong point of the spec, let's drop the reference to the env vars, and keep only the literal, default paths for them in the list. Of course, we do support the full XDG basedir spec in this regard, but it's one thing to implement it and another one to recommend it by documenting it. Replace "$HOME" by "~", because UNIX.
2016-04-12 00:48:31 +08:00
<filename>…</filename>
Reindent man pages to 2ch
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</literallayout></para>
man: describe unit load path in systemd.unit(5) In other cases where multiple directories are searched for unit files, the list of directories is described in the man page describing the format. I think this makes sense too in case of systemd directories, since the systemd(1) manpage already has an overview of many different topics.
2013-02-04 11:23:53 +08:00
man: shorten the list of unit file paths a bit Let's make this more digestable to read by making the list of documented unit file paths a bit shorter. Specifically, let's drop references to $XDG_CONFIG_HOME and $XDG_DATA_HOME, as their default values are listed too already. Given that the fact that the XDG basedir spec makes these paths configurable is probably not a strong point of the spec, let's drop the reference to the env vars, and keep only the literal, default paths for them in the list. Of course, we do support the full XDG basedir spec in this regard, but it's one thing to implement it and another one to recommend it by documenting it. Replace "$HOME" by "~", because UNIX.
2016-04-12 00:48:31 +08:00
<para><literallayout><filename>~/.config/systemd/user/*</filename>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<filename>/etc/systemd/user/*</filename>
Fix order and document user unit dirs Fixup for 718880ba0d 'add a transient user unit directory'.
2014-10-02 20:11:21 +08:00
<filename>$XDG_RUNTIME_DIR/systemd/user/*</filename>
man: describe unit load path in systemd.unit(5) In other cases where multiple directories are searched for unit files, the list of directories is described in the man page describing the format. I think this makes sense too in case of systemd directories, since the systemd(1) manpage already has an overview of many different topics.
2013-02-04 11:23:53 +08:00
<filename>/run/systemd/user/*</filename>
man: shorten the list of unit file paths a bit Let's make this more digestable to read by making the list of documented unit file paths a bit shorter. Specifically, let's drop references to $XDG_CONFIG_HOME and $XDG_DATA_HOME, as their default values are listed too already. Given that the fact that the XDG basedir spec makes these paths configurable is probably not a strong point of the spec, let's drop the reference to the env vars, and keep only the literal, default paths for them in the list. Of course, we do support the full XDG basedir spec in this regard, but it's one thing to implement it and another one to recommend it by documenting it. Replace "$HOME" by "~", because UNIX.
2016-04-12 00:48:31 +08:00
<filename>~/.local/share/systemd/user/*</filename>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<filename>/usr/lib/systemd/user/*</filename>
man: shorten the list of unit file paths a bit Let's make this more digestable to read by making the list of documented unit file paths a bit shorter. Specifically, let's drop references to $XDG_CONFIG_HOME and $XDG_DATA_HOME, as their default values are listed too already. Given that the fact that the XDG basedir spec makes these paths configurable is probably not a strong point of the spec, let's drop the reference to the env vars, and keep only the literal, default paths for them in the list. Of course, we do support the full XDG basedir spec in this regard, but it's one thing to implement it and another one to recommend it by documenting it. Replace "$HOME" by "~", because UNIX.
2016-04-12 00:48:31 +08:00
<filename>…</filename>
Reindent man pages to 2ch
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</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>,
Remove snapshot unit type Snapshots were never useful or used for anything. Many systemd developers that I spoke to at systemd.conf2015, didn't even know they existed, so it is fairly safe to assume that this type can be deleted without harm. The fundamental problem with snapshots is that the state of the system is dynamic, devices come and go, users log in and out, timers fire... and restoring all units to some state from the past would "undo" those changes, which isn't really possible. Tested by creating a snapshot, running the new binary, and checking that the transition did not cause errors, and the snapshot is gone, and snapshots cannot be created anymore. New systemctl says: Unknown operation snapshot. Old systemctl says: Failed to create snapshot: Support for snapshots has been removed. IgnoreOnSnaphost settings are warned about and ignored: Support for option IgnoreOnSnapshot= has been removed and it is ignored http://lists.freedesktop.org/archives/systemd-devel/2015-November/034872.html
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a resource management slice or
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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>,
Remove snapshot unit type Snapshots were never useful or used for anything. Many systemd developers that I spoke to at systemd.conf2015, didn't even know they existed, so it is fairly safe to assume that this type can be deleted without harm. The fundamental problem with snapshots is that the state of the system is dynamic, devices come and go, users log in and out, timers fire... and restoring all units to some state from the past would "undo" those changes, which isn't really possible. Tested by creating a snapshot, running the new binary, and checking that the transition did not cause errors, and the snapshot is gone, and snapshots cannot be created anymore. New systemctl says: Unknown operation snapshot. Old systemctl says: Failed to create snapshot: Support for snapshots has been removed. IgnoreOnSnaphost settings are warned about and ignored: Support for option IgnoreOnSnapshot= has been removed and it is ignored http://lists.freedesktop.org/archives/systemd-devel/2015-November/034872.html
2015-11-08 21:12:54 +08:00
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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<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>
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
<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: <literal>50</literal> refers to 50 seconds; <literal>2min 200ms</literal> refers to
2 minutes and 200 milliseconds, i.e. 120200 ms. The following time units are understood:
<literal>s</literal>, <literal>min</literal>, <literal>h</literal>, <literal>d</literal>,
man: describe what symlinks to unit do, and specify that presets must use real names The man pages didn't ever mention that symlinks to units can be created, and what exactly this means. Fix that omission, and disallow presets on alias names.
2016-08-13 21:38:12 +08:00
<literal>w</literal>, <literal>ms</literal>, <literal>us</literal>. For details see
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<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
<para>Empty lines and lines starting with <literal>#</literal> or <literal>;</literal> 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>Units can be aliased (have an alternative name), by creating a symlink from the new name
to the existing name in one of the unit search paths. For example,
<filename>systemd-networkd.service</filename> has the alias
<filename>dbus-org.freedesktop.network1.service</filename>, created during installation as the
symlink <filename>/usr/lib/systemd/system/dbus-org.freedesktop.network1.service</filename>. In
addition, unit files may specify aliases through the <varname>Alias=</varname> directive in the
[Install] section; those aliases are only effective when the unit is enabled. When the unit is
enabled, symlinks will be created for those names, and removed when the unit is disabled. For
example, <filename>reboot.target</filename> specifies
<varname>Alias=ctrl-alt-del.target</varname>, so when enabled it will be invoked whenever
CTRL+ALT+DEL is pressed. Alias names may be used in commands like <command>enable</command>,
<command>disable</command>, <command>start</command>, <command>stop</command>,
<command>status</command>, …, and in unit dependency directives <varname>Wants=</varname>,
<varname>Requires=</varname>, <varname>Before=</varname>, <varname>After=</varname>, …, with the
limitation that aliases specified through <varname>Alias=</varname> are only effective when the
unit is enabled. Aliases cannot be used with the <command>preset</command> command.</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>Wants=</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>Wants=</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
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<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
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>
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man: document that [Install] has no effect in unit file .d/*.conf drop-ins Fixes: #1774 Fixes: #1090
2016-02-11 04:39:36 +08:00
<para>Along with a unit file <filename>foo.service</filename>, a "drop-in" directory
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
<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 for a unit, without having to
modify unit files. Each drop-in file must have appropriate section headers. Note that for
instantiated units, this logic will first look for the instance <literal>.d/</literal>
subdirectory and read its <literal>.conf</literal> files, followed by the template
<literal>.d/</literal> subdirectory and the <literal>.conf</literal> files there. Also note that
man: typo fixes A mix of fixes for typos and UK english
2016-10-13 05:02:44 +08:00
settings from the <literal>[Install]</literal> section are not honored in drop-in unit files,
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
and have no effect.</para>
<para>In addition to <filename>/etc/systemd/system</filename>, the drop-in <literal>.d</literal>
directories for system services can be placed in <filename>/usr/lib/systemd/system</filename> or
<filename>/run/systemd/system</filename> directories. Drop-in files in <filename>/etc</filename>
take precedence over those in <filename>/run</filename> which in turn take precedence over those
in <filename>/usr/lib</filename>. Drop-in files under any of these directories take precedence
man: document *.d/ drop-in file order (#5262)
2017-02-08 07:58:02 +08:00
over unit files wherever located. Multiple drop-in files with different names are applied in
lexicographic order, regardless of which of the directories they reside in.</para>
man: mention that netdev,network files support dropins Also update the description of drop-ins in systemd.unit(5) to say that .d directories, not .conf files, are in /etc/system/system, /run/systemd/system, etc.
2016-09-10 21:34:07 +08:00
<!-- Note that we do not document .include here, as we consider it mostly obsolete, and want
people to use .d/ drop-ins instead. -->
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2015-02-04 10:14:13 +08:00
man: move bus-based/socket-based activation out of Automatic Dependencies section Fixes: #6793
2017-09-12 10:09:45 +08:00
<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>
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<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
doc: correct punctuation and improve typography in documentation
2014-08-03 13:11:12 +08:00
filename. Basically, given a path, "/" is replaced by "-", and all
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other characters which are not ASCII alphanumerics are replaced by
C-style "\x2d" escapes (except that "_" is never replaced and "."
is only replaced when it would be the first character in the
escaped path). The root directory "/" is encoded as single dash,
while otherwise the initial and ending "/" are removed from all
paths during transformation. This escaping is reversible. Properly
escaped paths can be generated using the
<citerefentry><refentrytitle>systemd-escape</refentrytitle><manvolnum>1</manvolnum></citerefentry>
command.</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
man: use https:// in URLs
2017-02-21 23:28:04 +08:00
url="https://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface
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Stability Promise</ulink>.</para>
</refsect1>
man: document automatic dependencies For all units ensure there's an "Automatic Dependencies" section in the man page, and explain which dependencies are automatically added in all cases, and which ones are added on top if DefaultDependencies=yes is set. This is also done for systemd.exec(5), systemd.resource-control(5) and systemd.unit(5) as these pages describe common behaviour of various unit types.
2015-11-12 03:47:07 +08:00
<refsect1>
<title>Automatic Dependencies</title>
<para>A number of unit dependencies are automatically established,
depending on unit configuration. On top of that, for units with
<varname>DefaultDependencies=yes</varname> (the default) a couple
of additional dependencies are added. The precise effect of
<varname>DefaultDependencies=yes</varname> depends on the unit
type (see below).</para>
<para>If <varname>DefaultDependencies=yes</varname> is set, units
that are referenced by other units of type
<filename>.target</filename> via a <varname>Wants=</varname> or
<varname>Requires=</varname> dependency might automatically gain
an <varname>Before=</varname> dependency too. See
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details.</para>
</refsect1>
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<refsect1>
nspawn: add new .nspawn files for container settings .nspawn fiels are simple settings files that may accompany container images and directories and contain settings otherwise passed on the nspawn command line. This provides an efficient way to attach execution data directly to containers.
2015-09-06 07:22:14 +08:00
<title>Unit File Load Path</title>
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<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>
man: MANAGER_SYSTEM understands SYSTEMD_UNIT_PATH too
2015-11-01 04:07:47 +08:00
<para>When the variable <varname>$SYSTEMD_UNIT_PATH</varname> is set,
the contents of this variable overrides the unit load path. If
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<varname>$SYSTEMD_UNIT_PATH</varname> ends with an empty component
(<literal>:</literal>), the usual unit load path will be appended
to the contents of the variable.</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>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<entry><filename>/etc/systemd/system</filename></entry>
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<entry>Local configuration</entry>
</row>
<row>
<entry><filename>/run/systemd/system</filename></entry>
<entry>Runtime units</entry>
</row>
<row>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<entry><filename>/usr/lib/systemd/system</filename></entry>
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<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 $XDG_CONFIG_HOME is not set)</entry>
</row>
<row>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<entry><filename>/etc/systemd/user</filename></entry>
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<entry>Local configuration</entry>
</row>
<row>
<entry><filename>$XDG_RUNTIME_DIR/systemd/user</filename></entry>
<entry>Runtime units (only used when $XDG_RUNTIME_DIR is set)</entry>
</row>
<row>
<entry><filename>/run/systemd/user</filename></entry>
<entry>Runtime units</entry>
</row>
<row>
<entry><filename>$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>
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<entry><filename>/usr/lib/systemd/user</filename></entry>
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<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>.
man: replace obsolete wiki link with man page
2015-03-05 07:43:20 +08:00
Also, some units are dynamically created via a
<citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
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</para>
</refsect1>
<refsect1>
<title>[Unit] Section Options</title>
doc: correct orthography, word forms and missing/extraneous words
2014-08-03 13:11:37 +08:00
<para>The unit file may include a [Unit] section, which carries
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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>
man: extend the docs on BindsTo= and Requires= a bit Let's emphasize that both really should be combined with After=.
2016-11-30 05:03:44 +08:00
<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 this dependency type does not imply that the other unit always has to be in active state when
this unit is running. Specifically: failing condition checks (such as <varname>ConditionPathExists=</varname>,
<varname>ConditionPathExists=</varname>, … — see below) do not cause the start job of a unit with a
<varname>Requires=</varname> dependency on it to fail. Also, some unit types may deactivate on their own (for
example, a service process may decide to exit cleanly, or a device may be unplugged by the user), which is not
propagated to units having a <varname>Requires=</varname> dependency. Use the <varname>BindsTo=</varname>
dependency type together with <varname>After=</varname> to ensure that a unit may never be in active state
without a specific other unit also in active state (see below).</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
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above.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>Requisite=</varname></term>
core: remove support for RequiresOverridable= and RequisiteOverridable= As discussed at systemd.conf 2015 and on also raised on the ML: http://lists.freedesktop.org/archives/systemd-devel/2015-November/034880.html This removes the two XyzOverridable= unit dependencies, that were basically never used, and do not enhance user experience in any way. Most folks looking for the functionality this provides probably opt for the "ignore-dependencies" job mode, and that's probably a good idea. Hence, let's simplify systemd's dependency engine and remove these two dependency types (and their inverses). The unit file parser and the dbus property parser will now redirect the settings/properties to result in an equivalent non-overridable dependency. In the case of the unit file parser we generate a warning, to inform the user. The dbus properties for this unit type stay available on the unit objects, but they are now hidden from usual introspection and will always return the empty list when queried. This should provide enough compatibility for the few unit files that actually ever made use of this.
2015-11-13 02:21:47 +08:00
<listitem><para>Similar to <varname>Requires=</varname>.
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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>
man: extend the docs on BindsTo= and Requires= a bit Let's emphasize that both really should be combined with After=.
2016-11-30 05:03:44 +08:00
<listitem><para>Configures requirement dependencies, very similar in style to
<varname>Requires=</varname>. However, this dependency type is stronger: in addition to the effect of
<varname>Requires=</varname> it declares that if the unit bound to is stopped, this unit will be stopped
too. This means a unit bound to another unit that suddenly enters inactive state will be stopped too.
Units can suddenly, unexpectedly enter inactive state for different reasons: the main process of a service unit
might terminate on its own choice, the backing device of a device unit might be unplugged or the mount point of
a mount unit might be unmounted without involvement of the system and service manager.</para>
<para>When used in conjunction with <varname>After=</varname> on the same unit the behaviour of
<varname>BindsTo=</varname> is even stronger. In this case, the unit bound to strictly has to be in active
state for this unit to also be in active state. This not only means a unit bound to another unit that suddenly
enters inactive state, but also one that is bound to another unit that gets skipped due to a failed condition
check (such as <varname>ConditionPathExists=</varname>, <varname>ConditionPathIsSymbolicLink=</varname>, … —
see below) will be stopped, should it be running. Hence, in many cases it is best to combine
<varname>BindsTo=</varname> with <varname>After=</varname>.</para></listitem>
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</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>
man: extend Before=/After= documentation a bit let's clarify what the order actually means for service units. Fixes: #6097
2017-06-27 01:23:54 +08:00
<listitem><para>These two settings expect a space-separated list of unit names. They configure 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> has finished starting up. Note that this setting is
independent of and orthogonal to the requirement dependencies as configured by <varname>Requires=</varname>,
<varname>Wants=</varname> or <varname>BindsTo=</varname>. It is a common pattern to include a unit name in both
the <varname>After=</varname> and <varname>Requires=</varname> options, 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, 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. Given two units with any ordering dependency between them, if one unit is shut down and the other is
started up, the shutdown is ordered before the start-up. It doesn't matter if the ordering dependency is
<varname>After=</varname> or <varname>Before=</varname>, in this case. It also doesn't matter which of the two
is shut down, as long as one is shut down and the other is started up. The shutdown is ordered before the
start-up in all cases. If two units have no ordering dependencies between them, they are shut down or started
up simultaneously, and no ordering takes place. It depends on the unit type when precisely a unit has finished
starting up. Most importantly, for service units start-up is considered completed for the purpose of
<varname>Before=</varname>/<varname>After=</varname> when all its configured start-up commands have been
invoked and they either failed or reported start-up success.</para></listitem>
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</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>,
/var/tmp instead of /tmp/var in systemd.unit man page (#3262)
2016-05-16 09:43:00 +08:00
<filename>/var/tmp</filename> and network namespace as one
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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
man: revert documentation about RequiresMountsFor= honoring noauto This effectively reverts commit 5d2abc04fc95f5c5f6d0eaf2f: Author: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Date: Wed Apr 16 22:15:42 2014 -0400 man: document relationship between RequiresMountsFor and noauto https://bugzilla.redhat.com/show_bug.cgi?id=1088057 Fixes #5249.
2017-02-09 09:23:12 +08:00
mounted automatically through <filename>local-fs.target</filename>,
but are still honored for the purposes of this option, i.e. they
will be pulled in by this unit.</para></listitem>
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</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>
man: describe which units types are stopped on isolate Fixes #6455.
2017-07-27 03:25:50 +08:00
<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> for service, target, socket, busname, timer, and path
units, and <option>true</option> for slice, scope, device, swap, mount, and
automount units.</para></listitem>
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</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
doc: correct punctuation and improve typography in documentation
2014-08-03 13:11:12 +08:00
longer used. Note that, in order to minimize the work to be
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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>
job: add JobRunningTimeoutSec for JOB_RUNNING state Unit.JobTimeoutSec starts when a job is enqueued in a transaction. The introduced distinct Unit.JobRunningTimeoutSec starts only when the job starts running (e.g. it groups all Exec* commands of a service or spans waiting for a device period.) Unit.JobRunningTimeoutSec is intended to be used by default instead of Unit.JobTimeoutSec for device units where such behavior causes less confusion (consider a job for a _netdev mount device, with this change the timeout will start ticking only after the network is ready).
2017-02-18 00:47:20 +08:00
<term><varname>JobRunningTimeoutSec=</varname></term>
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<term><varname>JobTimeoutAction=</varname></term>
<term><varname>JobTimeoutRebootArgument=</varname></term>
job: add JobRunningTimeoutSec for JOB_RUNNING state Unit.JobTimeoutSec starts when a job is enqueued in a transaction. The introduced distinct Unit.JobRunningTimeoutSec starts only when the job starts running (e.g. it groups all Exec* commands of a service or spans waiting for a device period.) Unit.JobRunningTimeoutSec is intended to be used by default instead of Unit.JobTimeoutSec for device units where such behavior causes less confusion (consider a job for a _netdev mount device, with this change the timeout will start ticking only after the network is ready).
2017-02-18 00:47:20 +08:00
<listitem><para>When a job for this unit is queued, a time-out <varname>JobTimeoutSec=</varname> may be
configured. Similarly, <varname>JobRunningTimeoutSec=</varname> starts counting when the queued job is actually
started. If either 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 <literal>infinity</literal> (job timeouts
disabled), except for device units (<varname>JobRunningTimeoutSec=</varname> defaults to
<varname>DefaultTimeoutStartSec=</varname>). NB: this timeout is independent from any unit-specific timeout
(for example, the timeout set with <varname>TimeoutStartSec=</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>
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man: update reference to definition of StartLimitAction (#6786) The values for StartLimitAction are defined in `man systemd.unit`. Don't send people to `man systemd.service` just to find they need to look back in `man systemd.unit` again :).
2017-09-09 20:54:23 +08:00
<para><varname>JobTimeoutAction=</varname> optionally configures an additional action to take when the time-out
is hit. It takes the same values as <varname>StartLimitAction=</varname>. Defaults to <option>none</option>.
<varname>JobTimeoutRebootArgument=</varname> configures an optional reboot string to pass to the
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<citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
system call.</para></listitem>
</varlistentry>
core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section into the [Unit] section of unit files, and thus support it in all unit types, not just in services. This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that repeated start-up failure due to failed conditions is also considered for the start limit logic. For compatibility the four options may also be configured in the [Service] section still, but we only document them in their new section [Unit]. This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express more clearly what it is about, after all it's only triggered through the start limit being hit. Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike. Fixes: #2467
2016-02-10 01:38:03 +08:00
<varlistentry>
core: rename StartLimitInterval= to StartLimitIntervalSec= We generally follow the rule that for time settings we suffix the setting name with "Sec" to indicate the default unit if none is specified. The only exception was the rate limiting interval settings. Fix this, and keep the old names for compatibility. Do the same for journald's RateLimitInterval= setting
2016-04-27 02:46:20 +08:00
<term><varname>StartLimitIntervalSec=</varname></term>
core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section into the [Unit] section of unit files, and thus support it in all unit types, not just in services. This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that repeated start-up failure due to failed conditions is also considered for the start limit logic. For compatibility the four options may also be configured in the [Service] section still, but we only document them in their new section [Unit]. This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express more clearly what it is about, after all it's only triggered through the start limit being hit. Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike. Fixes: #2467
2016-02-10 01:38:03 +08:00
<term><varname>StartLimitBurst=</varname></term>
<listitem><para>Configure unit start rate limiting. By default, units which are started more than 5 times
within 10 seconds are not permitted to start any more times until the 10 second interval ends. With these two
core: rename StartLimitInterval= to StartLimitIntervalSec= We generally follow the rule that for time settings we suffix the setting name with "Sec" to indicate the default unit if none is specified. The only exception was the rate limiting interval settings. Fix this, and keep the old names for compatibility. Do the same for journald's RateLimitInterval= setting
2016-04-27 02:46:20 +08:00
options, this rate limiting may be modified. Use <varname>StartLimitIntervalSec=</varname> to configure the
checking interval (defaults to <varname>DefaultStartLimitIntervalSec=</varname> in manager configuration file,
set to 0 to disable any kind of rate limiting). Use <varname>StartLimitBurst=</varname> to configure how many
core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section into the [Unit] section of unit files, and thus support it in all unit types, not just in services. This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that repeated start-up failure due to failed conditions is also considered for the start limit logic. For compatibility the four options may also be configured in the [Service] section still, but we only document them in their new section [Unit]. This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express more clearly what it is about, after all it's only triggered through the start limit being hit. Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike. Fixes: #2467
2016-02-10 01:38:03 +08:00
starts per interval are allowed (defaults to <varname>DefaultStartLimitBurst=</varname> in manager
configuration file). These configuration options are particularly useful in conjunction with the service
setting <varname>Restart=</varname> (see
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>); however,
they apply to all kinds of starts (including manual), not just those triggered by the
<varname>Restart=</varname> logic. Note that units which are configured for <varname>Restart=</varname> and
which reach the start limit are not attempted to be restarted anymore; however, they may still be restarted
manually at a later point, from which point on, the restart logic is again activated. Note that
<command>systemctl reset-failed</command> will cause the restart rate counter for a service to be flushed,
which is useful if the administrator wants to manually start a unit and the start limit interferes with
core: move start ratelimiting check after condition checks With #2564 unit start rate limiting was moved from after the condition checks are to before they are made, in an attempt to fix #2467. This however resulted in #2684. However, with a previous commit a concept of per socket unit trigger rate limiting has been added, to fix #2467 more comprehensively, hence the start limit can be moved after the condition checks again, thus fixing #2684. Fixes: #2684
2016-04-27 02:34:33 +08:00
that. Note that this rate-limiting is enforced after any unit condition checks are executed, and hence unit
core: move enforcement of the start limit into per-unit-type code again Let's move the enforcement of the per-unit start limit from unit.c into the type-specific files again. For unit types that know a concept of "result" codes this allows us to hook up the start limit condition to it with an explicit result code. Also, this makes sure that the state checks in clal like service_start() may be done before the start limit is checked, as the start limit really should be checked last, right before everything has been verified to be in order. The generic start limit logic is left in unit.c, but the invocation of it is moved into the per-type files, in the various xyz_start() functions, so that they may place the check at the right location. Note that this change drops the enforcement entirely from device, slice, target and scope units, since these unit types generally may not fail activation, or may only be activated a single time. This is also documented now. Note that restores the "start-limit-hit" result code that existed before 6bf0f408e4833152197fb38fb10a9989c89f3a59 already in the service code. However, it's not introduced for all units that have a result code concept. Fixes #3166.
2016-05-02 19:01:26 +08:00
activations with failing conditions are not counted by this rate limiting. Slice, target, device and scope
units do not enforce this setting, as they are unit types whose activation may either never fail, or may
succeed only a single time.</para></listitem>
core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section into the [Unit] section of unit files, and thus support it in all unit types, not just in services. This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that repeated start-up failure due to failed conditions is also considered for the start limit logic. For compatibility the four options may also be configured in the [Service] section still, but we only document them in their new section [Unit]. This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express more clearly what it is about, after all it's only triggered through the start limit being hit. Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike. Fixes: #2467
2016-02-10 01:38:03 +08:00
</varlistentry>
<varlistentry>
<term><varname>StartLimitAction=</varname></term>
<listitem><para>Configure the action to take if the rate limit configured with
core: rename StartLimitInterval= to StartLimitIntervalSec= We generally follow the rule that for time settings we suffix the setting name with "Sec" to indicate the default unit if none is specified. The only exception was the rate limiting interval settings. Fix this, and keep the old names for compatibility. Do the same for journald's RateLimitInterval= setting
2016-04-27 02:46:20 +08:00
<varname>StartLimitIntervalSec=</varname> and <varname>StartLimitBurst=</varname> is hit. Takes one of
core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section into the [Unit] section of unit files, and thus support it in all unit types, not just in services. This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that repeated start-up failure due to failed conditions is also considered for the start limit logic. For compatibility the four options may also be configured in the [Service] section still, but we only document them in their new section [Unit]. This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express more clearly what it is about, after all it's only triggered through the start limit being hit. Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike. Fixes: #2467
2016-02-10 01:38:03 +08:00
<option>none</option>, <option>reboot</option>, <option>reboot-force</option>,
<option>reboot-immediate</option>, <option>poweroff</option>, <option>poweroff-force</option> or
<option>poweroff-immediate</option>. If <option>none</option> is set, hitting the rate limit will trigger no
action besides that the start will not be permitted. <option>reboot</option> causes a reboot following the
normal shutdown procedure (i.e. equivalent to <command>systemctl reboot</command>).
<option>reboot-force</option> causes a forced reboot which will terminate all processes forcibly but should
cause no dirty file systems on reboot (i.e. equivalent to <command>systemctl reboot -f</command>) and
<option>reboot-immediate</option> causes immediate execution of the
<citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry> system call, which
might result in data loss. Similarly, <option>poweroff</option>, <option>poweroff-force</option>,
<option>poweroff-immediate</option> have the effect of powering down the system with similar
semantics. Defaults to <option>none</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>RebootArgument=</varname></term>
<listitem><para>Configure the optional argument for the
<citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry> system call if
<varname>StartLimitAction=</varname> or a service's <varname>FailureAction=</varname> is a reboot action. This
works just like the optional argument to <command>systemctl reboot</command> command.</para></listitem>
</varlistentry>
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<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>
core: add ConditionUser and ConditionGroup This adds two options that are useful for user units. In particular, it is useful to check ConditionUser=!0 to not start for the root user. Closes: #5187
2017-04-09 07:32:13 +08:00
<term><varname>ConditionUser=</varname></term>
<term><varname>ConditionGroup=</varname></term>
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doc: use expanded forms for written style
2015-10-26 22:45:12 +08:00
<!-- We do not document ConditionNull=
doc: correct punctuation and improve typography in documentation
2014-08-03 13:11:12 +08:00
here, as it is not particularly
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useful and probably just
confusing. -->
man: document distinction between ConditionXYZ= and AssertXYZ= References: #2468
2016-02-11 04:30:25 +08:00
<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 (mostly silently) 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. Use condition expressions in order to silently skip
units that do not apply to the local running system, for example because the kernel or runtime environment
doesn't require its functionality. Use the various <varname>AssertArchitecture=</varname>,
<varname>AssertVirtualization=</varname>, … options for a similar mechanism that puts the unit in a failure
state and logs about the failed check (see below).</para>
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<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>,
man: fix typo m86k → m68k (#5993)
2017-05-19 17:37:30 +08:00
<varname>m68k</varname>,
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2015-02-04 10:14:13 +08:00
<varname>tilegx</varname>,
architecture: add Synopsys DesignWare ARC cores support (#5992) DesignWare ARC Processors are a family of 32-bit CPUs from Synopsys used extensively in SoCs of different vendors.
2017-05-19 22:55:24 +08:00
<varname>cris</varname>,
<varname>arc</varname>,
<varname>arc-be</varname> to test
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against a specific architecture. The architecture is
determined from the information returned by
man: fix a bunch of links All hail linkchecker!
2015-03-14 10:22:39 +08:00
<citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
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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>zvm</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>,
detect-virt: add rkt app container runtime
2015-11-09 21:37:43 +08:00
<varname>docker</varname>,
<varname>rkt</varname> to test
detect-virt: add --private-users switch to check if a userns is active Various things don't work when we're running in a user namespace, but it's pretty hard to reliably detect if that is true. A function is added which looks at /proc/self/uid_map and returns false if the default "0 0 UINT32_MAX" is found, and true if it finds anything else. This misses the case where an 1:1 mapping with the full range was used, but I don't know how to distinguish this case. 'systemd-detect-virt --private-users' is very similar to 'systemd-detect-virt --chroot', but we check for a user namespace instead.
2016-10-21 11:41:21 +08:00
against a specific implementation, or
<varname>private-users</varname> to check whether we are running in a user namespace. See
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<citerefentry><refentrytitle>systemd-detect-virt</refentrytitle><manvolnum>1</manvolnum></citerefentry>
for a full list of known virtualization technologies and their
identifiers. 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
man: fix typos
2016-01-15 19:46:08 +08:00
system. Currently, the recognized values are
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<varname>selinux</varname>,
<varname>apparmor</varname>,
<varname>ima</varname>,
<varname>smack</varname> and
<varname>audit</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>,
man: fix typos
2015-12-27 01:25:49 +08:00
to make sure they run before the stamp file's modification
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time gets reset indicating a completed update.</para>
man: be more precise on the ConditionFirstBoot= documentation Fixes: #5696
2017-06-27 01:11:09 +08:00
<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 (specifically: an <filename>/etc</filename> with no <filename>/etc/machine-id</filename>). This may
be used to populate <filename>/etc</filename> on the first boot after factory reset, or when a new system
instance boots up for the first time.</para>
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<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>
core: add ConditionUser and ConditionGroup This adds two options that are useful for user units. In particular, it is useful to check ConditionUser=!0 to not start for the root user. Closes: #5187
2017-04-09 07:32:13 +08:00
<para><varname>ConditionUser=</varname> takes a numeric
core: add @system special value to ConditionUser= It allows checking if the user is a system user or a normal user
2017-05-19 10:12:14 +08:00
<literal>UID</literal>, a UNIX user name, or the special value
<literal>@system</literal>. This condition may be used to check
whether the service manager is running as the given user. The
special value <literal>@system</literal> can be used to check
if the user id is within the system user range. This option is not
core: add ConditionUser and ConditionGroup This adds two options that are useful for user units. In particular, it is useful to check ConditionUser=!0 to not start for the root user. Closes: #5187
2017-04-09 07:32:13 +08:00
useful for system services, as the system manager exclusively
runs as the root user, and thus the test result is constant.</para>
<para><varname>ConditionGroup=</varname> is similar
to <varname>ConditionUser=</varname> but verifies that the
service manager's real or effective group, or any of its
core: add @system special value to ConditionUser= It allows checking if the user is a system user or a normal user
2017-05-19 10:12:14 +08:00
auxiliary groups match the specified group or GID. This setting
does not have a special value <literal>@system</literal>.</para>
core: add ConditionUser and ConditionGroup This adds two options that are useful for user units. In particular, it is useful to check ConditionUser=!0 to not start for the root user. Closes: #5187
2017-04-09 07:32:13 +08:00
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<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>AssertArchitecture=</varname></term>
<term><varname>AssertVirtualization=</varname></term>
<term><varname>AssertHost=</varname></term>
<term><varname>AssertKernelCommandLine=</varname></term>
<term><varname>AssertSecurity=</varname></term>
<term><varname>AssertCapability=</varname></term>
<term><varname>AssertACPower=</varname></term>
<term><varname>AssertNeedsUpdate=</varname></term>
<term><varname>AssertFirstBoot=</varname></term>
<term><varname>AssertPathExists=</varname></term>
<term><varname>AssertPathExistsGlob=</varname></term>
<term><varname>AssertPathIsDirectory=</varname></term>
<term><varname>AssertPathIsSymbolicLink=</varname></term>
<term><varname>AssertPathIsMountPoint=</varname></term>
<term><varname>AssertPathIsReadWrite=</varname></term>
<term><varname>AssertDirectoryNotEmpty=</varname></term>
<term><varname>AssertFileNotEmpty=</varname></term>
<term><varname>AssertFileIsExecutable=</varname></term>
core: add ConditionUser and ConditionGroup This adds two options that are useful for user units. In particular, it is useful to check ConditionUser=!0 to not start for the root user. Closes: #5187
2017-04-09 07:32:13 +08:00
<term><varname>AssertUser=</varname></term>
<term><varname>AssertGroup=</varname></term>
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man: document distinction between ConditionXYZ= and AssertXYZ= References: #2468
2016-02-11 04:30:25 +08:00
<listitem><para>Similar to the <varname>ConditionArchitecture=</varname>,
<varname>ConditionVirtualization=</varname>, …, condition settings described above, these settings add
assertion checks to the start-up of the unit. However, unlike the conditions settings, any assertion setting
man: follow up fixes for #2575
2016-02-11 08:49:40 +08:00
that is not met results in failure of the start job (which means this is logged loudly). Use assertion
expressions for units that cannot operate when specific requirements are not met, and when this is something
the administrator or user should look into.</para></listitem>
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</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>
cgroup: add support for net_cls controllers Add a new config directive called NetClass= to CGroup enabled units. Allowed values are positive numbers for fix assignments and "auto" for picking a free value automatically, for which we need to keep track of dynamically assigned net class IDs of units. Introduce a hash table for this, and also record the last ID that was given out, so the allocator can start its search for the next 'hole' from there. This could eventually be optimized with something like an irb. The class IDs up to 65536 are considered reserved and won't be assigned automatically by systemd. This barrier can be made a config directive in the future. Values set in unit files are stored in the CGroupContext of the unit and considered read-only. The actually assigned number (which may have been chosen dynamically) is stored in the unit itself and is guaranteed to remain stable as long as the unit is active. In the CGroup controller, set the configured CGroup net class to net_cls.classid. Multiple unit may share the same net class ID, and those which do are linked together.
2015-01-16 03:08:42 +08:00
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</variablelist>
</refsect1>
<refsect1>
<title>[Install] Section Options</title>
man: document that [Install] has no effect in unit file .d/*.conf drop-ins Fixes: #1774 Fixes: #1090
2016-02-11 04:39:36 +08:00
<para>Unit files may include an <literal>[Install]</literal> 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 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. Note that settings in the <literal>[Install]</literal> section may not appear in
<filename>.d/*.conf</filename> unit file drop-ins (see above).</para>
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<variablelist class='unit-directives'>
<varlistentry>
<term><varname>Alias=</varname></term>
man: document that some unit types do not support unit aliases via symlinks
2016-04-29 23:48:07 +08:00
<listitem><para>A space-separated 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. Note that not all unit types support such alias names, and this
setting is not supported for them. Specifically, mount, slice, swap, and automount units do not support
aliasing.</para></listitem>
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</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>
man: document that %f in units always unescapes (#3578)
2016-06-23 05:28:12 +08:00
<entry>This is either the unescaped instance name (if applicable) with <filename>/</filename> prepended (if applicable), or the unescaped prefix name prepended with <filename>/</filename>.</entry>
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</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>
core: simplify handling of %u, %U, %s and %h unit file specifiers Previously, the %u, %U, %s and %h specifiers would resolve to the user name, numeric user ID, shell and home directory of the user configured in the User= setting of a unit file, or the user of the manager instance if no User= setting was configured. That at least was the theory. In real-life this was not ever actually useful: - For the systemd --user instance it made no sense to ever set User=, since the instance runs in user context after all, and hence the privileges to change user IDs don't even exist. The four specifiers were actually not useful at all in this case. - For the systemd --system instance we did not allow any resolving that would require NSS. Hence, %s and %h were not supported, unless User=root was set, in which case they would be hardcoded to /bin/sh and /root, to avoid NSS. Then, %u would actually resolve to whatever was set with User=, but %U would only resolve to the numeric UID of that setting if the User= was specified in numeric form, or happened to be root (in which case 0 was hardcoded as mapping). Two of the specifiers are entirely useless in this case, one is realistically also useless, and one is pretty pointless. - Resolving of these settings would only happen if User= was actually set *before* the specifiers where resolved. This behaviour was undocumented and is really ugly, as specifiers should actually be considered something that applies to the whole file equally, independently of order... With this change, %u, %U, %s and %h are drastically simplified: they now always refer to the user that is running the service instance, and the user configured in the unit file is irrelevant. For the system instance of systemd this means they always resolve to "root", "0", "/bin/sh" and "/root", thus avoiding NSS. For the user instance, to the data for the specific user. The new behaviour is identical to the old behaviour in all --user cases and for all units that have no User= set (or set to "0" or "root").
2015-11-01 05:12:51 +08:00
<entry>This is the name of the user running the service manager instance. In case of the system manager this resolves to <literal>root</literal>.</entry>
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</row>
<row>
<entry><literal>%U</literal></entry>
<entry>User UID</entry>
core: simplify handling of %u, %U, %s and %h unit file specifiers Previously, the %u, %U, %s and %h specifiers would resolve to the user name, numeric user ID, shell and home directory of the user configured in the User= setting of a unit file, or the user of the manager instance if no User= setting was configured. That at least was the theory. In real-life this was not ever actually useful: - For the systemd --user instance it made no sense to ever set User=, since the instance runs in user context after all, and hence the privileges to change user IDs don't even exist. The four specifiers were actually not useful at all in this case. - For the systemd --system instance we did not allow any resolving that would require NSS. Hence, %s and %h were not supported, unless User=root was set, in which case they would be hardcoded to /bin/sh and /root, to avoid NSS. Then, %u would actually resolve to whatever was set with User=, but %U would only resolve to the numeric UID of that setting if the User= was specified in numeric form, or happened to be root (in which case 0 was hardcoded as mapping). Two of the specifiers are entirely useless in this case, one is realistically also useless, and one is pretty pointless. - Resolving of these settings would only happen if User= was actually set *before* the specifiers where resolved. This behaviour was undocumented and is really ugly, as specifiers should actually be considered something that applies to the whole file equally, independently of order... With this change, %u, %U, %s and %h are drastically simplified: they now always refer to the user that is running the service instance, and the user configured in the unit file is irrelevant. For the system instance of systemd this means they always resolve to "root", "0", "/bin/sh" and "/root", thus avoiding NSS. For the user instance, to the data for the specific user. The new behaviour is identical to the old behaviour in all --user cases and for all units that have no User= set (or set to "0" or "root").
2015-11-01 05:12:51 +08:00
<entry>This is the numeric UID of the user running the service manager instance. In case of the system manager this resolves to <literal>0</literal>.</entry>
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</row>
<row>
<entry><literal>%h</literal></entry>
<entry>User home directory</entry>
core: simplify handling of %u, %U, %s and %h unit file specifiers Previously, the %u, %U, %s and %h specifiers would resolve to the user name, numeric user ID, shell and home directory of the user configured in the User= setting of a unit file, or the user of the manager instance if no User= setting was configured. That at least was the theory. In real-life this was not ever actually useful: - For the systemd --user instance it made no sense to ever set User=, since the instance runs in user context after all, and hence the privileges to change user IDs don't even exist. The four specifiers were actually not useful at all in this case. - For the systemd --system instance we did not allow any resolving that would require NSS. Hence, %s and %h were not supported, unless User=root was set, in which case they would be hardcoded to /bin/sh and /root, to avoid NSS. Then, %u would actually resolve to whatever was set with User=, but %U would only resolve to the numeric UID of that setting if the User= was specified in numeric form, or happened to be root (in which case 0 was hardcoded as mapping). Two of the specifiers are entirely useless in this case, one is realistically also useless, and one is pretty pointless. - Resolving of these settings would only happen if User= was actually set *before* the specifiers where resolved. This behaviour was undocumented and is really ugly, as specifiers should actually be considered something that applies to the whole file equally, independently of order... With this change, %u, %U, %s and %h are drastically simplified: they now always refer to the user that is running the service instance, and the user configured in the unit file is irrelevant. For the system instance of systemd this means they always resolve to "root", "0", "/bin/sh" and "/root", thus avoiding NSS. For the user instance, to the data for the specific user. The new behaviour is identical to the old behaviour in all --user cases and for all units that have no User= set (or set to "0" or "root").
2015-11-01 05:12:51 +08:00
<entry>This is the home directory of the user running the service manager instance. In case of the system manager this resolves to <literal>/root</literal>.</entry>
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</row>
<row>
<entry><literal>%s</literal></entry>
<entry>User shell</entry>
core: simplify handling of %u, %U, %s and %h unit file specifiers Previously, the %u, %U, %s and %h specifiers would resolve to the user name, numeric user ID, shell and home directory of the user configured in the User= setting of a unit file, or the user of the manager instance if no User= setting was configured. That at least was the theory. In real-life this was not ever actually useful: - For the systemd --user instance it made no sense to ever set User=, since the instance runs in user context after all, and hence the privileges to change user IDs don't even exist. The four specifiers were actually not useful at all in this case. - For the systemd --system instance we did not allow any resolving that would require NSS. Hence, %s and %h were not supported, unless User=root was set, in which case they would be hardcoded to /bin/sh and /root, to avoid NSS. Then, %u would actually resolve to whatever was set with User=, but %U would only resolve to the numeric UID of that setting if the User= was specified in numeric form, or happened to be root (in which case 0 was hardcoded as mapping). Two of the specifiers are entirely useless in this case, one is realistically also useless, and one is pretty pointless. - Resolving of these settings would only happen if User= was actually set *before* the specifiers where resolved. This behaviour was undocumented and is really ugly, as specifiers should actually be considered something that applies to the whole file equally, independently of order... With this change, %u, %U, %s and %h are drastically simplified: they now always refer to the user that is running the service instance, and the user configured in the unit file is irrelevant. For the system instance of systemd this means they always resolve to "root", "0", "/bin/sh" and "/root", thus avoiding NSS. For the user instance, to the data for the specific user. The new behaviour is identical to the old behaviour in all --user cases and for all units that have no User= set (or set to "0" or "root").
2015-11-01 05:12:51 +08:00
<entry>This is the shell of the user running the service manager instance. In case of the system manager this resolves to <literal>/bin/sh</literal>.</entry>
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</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>
treewide: fix typos
2015-04-30 17:57:09 +08:00
<entry>The hostname of the running system at the point in time the unit configuration is loaded.</entry>
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</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>Examples</title>
<example>
<title>Allowing units to be enabled</title>
<para>The following snippet (highlighted) allows a unit (e.g.
<filename>foo.service</filename>) to be enabled via
<command>systemctl enable</command>:</para>
<programlisting>[Unit]
man: systemd.unit(5): add examples for common tasks Add examples for (a) how to allow units to be enabled and (b) overriding vendor settings to the man page.
2015-01-24 21:04:03 +08:00
Description=Foo
[Service]
ExecStart=/usr/sbin/foo-daemon
<emphasis>[Install]</emphasis>
<emphasis>WantedBy=multi-user.target</emphasis></programlisting>
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<para>After running <command>systemctl enable</command>, a
symlink
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
2015-06-19 01:47:44 +08:00
<filename>/etc/systemd/system/multi-user.target.wants/foo.service</filename>
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linking to the actual unit will be created. It tells systemd to
pull in the unit when starting
<filename>multi-user.target</filename>. The inverse
<command>systemctl disable</command> will remove that symlink
again.</para>
</example>
<example>
<title>Overriding vendor settings</title>
<para>There are two methods of overriding vendor settings in
unit files: copying the unit file from
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<filename>/usr/lib/systemd/system</filename> to
<filename>/etc/systemd/system</filename> and modifying the
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chosen settings. Alternatively, one can create a directory named
<filename><replaceable>unit</replaceable>.d/</filename> within
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<filename>/etc/systemd/system</filename> and place a drop-in
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file <filename><replaceable>name</replaceable>.conf</filename>
there that only changes the specific settings one is interested
in. Note that multiple such drop-in files are read if
man: document *.d/ drop-in file order (#5262)
2017-02-08 07:58:02 +08:00
present, processed in lexicographic order of their filename.</para>
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<para>The advantage of the first method is that one easily
overrides the complete unit, the vendor unit is not parsed at
all anymore. It has the disadvantage that improvements to the
unit file by the vendor are not automatically incorporated on
updates.</para>
<para>The advantage of the second method is that one only
overrides the settings one specifically wants, where updates to
the unit by the vendor automatically apply. This has the
disadvantage that some future updates by the vendor might be
incompatible with the local changes.</para>
<para>Note that for drop-in files, if one wants to remove
entries from a setting that is parsed as a list (and is not a
dependency), such as <varname>ConditionPathExists=</varname> (or
e.g. <varname>ExecStart=</varname> in service units), one needs
to first clear the list before re-adding all entries except the
one that is to be removed. See below for an example.</para>
<para>This also applies for user instances of systemd, but with
different locations for the unit files. See the section on unit
load paths for further details.</para>
<para>Suppose there is a vendor-supplied unit
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<filename>/usr/lib/systemd/system/httpd.service</filename> with
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the following contents:</para>
<programlisting>[Unit]
man: systemd.unit(5): add examples for common tasks Add examples for (a) how to allow units to be enabled and (b) overriding vendor settings to the man page.
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Description=Some HTTP server
After=remote-fs.target sqldb.service
Requires=sqldb.service
AssertPathExists=/srv/webserver
[Service]
Type=notify
ExecStart=/usr/sbin/some-fancy-httpd-server
Nice=5
[Install]
WantedBy=multi-user.target</programlisting>
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<para>Now one wants to change some settings as an administrator:
firstly, in the local setup, <filename>/srv/webserver</filename>
treewide: correct typos and use consistent "MAC" spelling
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might not exist, because the HTTP server is configured to use
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<filename>/srv/www</filename> instead. Secondly, the local
configuration makes the HTTP server also depend on a memory
cache service, <filename>memcached.service</filename>, that
should be pulled in (<varname>Requires=</varname>) and also be
ordered appropriately (<varname>After=</varname>). Thirdly, in
order to harden the service a bit more, the administrator would
like to set the <varname>PrivateTmp=</varname> setting (see
doc: fix incorrect reference (#5784)
2017-04-23 21:10:39 +08:00
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
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for details). And lastly, the administrator would like to reset
the niceness of the service to its default value of 0.</para>
<para>The first possibility is to copy the unit file to
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<filename>/etc/systemd/system/httpd.service</filename> and
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change the chosen settings:</para>
<programlisting>[Unit]
man: systemd.unit(5): add examples for common tasks Add examples for (a) how to allow units to be enabled and (b) overriding vendor settings to the man page.
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Description=Some HTTP server
After=remote-fs.target sqldb.service <emphasis>memcached.service</emphasis>
Requires=sqldb.service <emphasis>memcached.service</emphasis>
AssertPathExists=<emphasis>/srv/www</emphasis>
[Service]
Type=notify
ExecStart=/usr/sbin/some-fancy-httpd-server
<emphasis>Nice=0</emphasis>
<emphasis>PrivateTmp=yes</emphasis>
[Install]
WantedBy=multi-user.target</programlisting>
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<para>Alternatively, the administrator could create a drop-in
file
man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.
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<filename>/etc/systemd/system/httpd.service.d/local.conf</filename>
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with the following contents:</para>
man: systemd.unit(5): add examples for common tasks Add examples for (a) how to allow units to be enabled and (b) overriding vendor settings to the man page.
2015-01-24 21:04:03 +08:00
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<programlisting>[Unit]
man: systemd.unit(5): add examples for common tasks Add examples for (a) how to allow units to be enabled and (b) overriding vendor settings to the man page.
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After=memcached.service
Requires=memcached.service
# Reset all assertions and then re-add the condition we want
AssertPathExists=
AssertPathExists=/srv/www
[Service]
Nice=0
PrivateTmp=yes</programlisting>
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<para>Note that dependencies (<varname>After=</varname>, etc.)
cannot be reset to an empty list, so dependencies can only be
added in drop-ins. If you want to remove dependencies, you have
to override the entire unit.</para>
man: describe precedence of drop-in .conf files over unit files
2015-12-18 11:41:59 +08:00
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</example>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.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.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><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
man: fix a bunch of links All hail linkchecker!
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<citerefentry project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>1</manvolnum></citerefentry>
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</para>
</refsect1>
man: add some initial man page work
2010-05-16 05:06:41 +08:00
</refentry>
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