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systemd/man/systemd.target.xml
Lennart Poettering f32b43bda4 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.
2015-11-12 19:27:24 +01:00

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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2010 Lennart Poettering
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="systemd.target">
<refentryinfo>
<title>systemd.target</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.target</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd.target</refname>
<refpurpose>Target unit configuration</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename><replaceable>target</replaceable>.target</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>A unit configuration file whose name ends in
<literal>.target</literal> encodes information about a target unit
of systemd, which is used for grouping units and as well-known
synchronization points during start-up.</para>
<para>This unit type has no specific options. See
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for the common options of all unit configuration files. The common
configuration items are configured in the generic [Unit] and
[Install] sections. A separate [Target] section does not exist,
since no target-specific options may be configured.</para>
<para>Target units do not offer any additional functionality on
top of the generic functionality provided by units. They exist
merely to group units via dependencies (useful as boot targets),
and to establish standardized names for synchronization points
used in dependencies between units. Among other things, target
units are a more flexible replacement for SysV runlevels in the
classic SysV init system. (And for compatibility reasons special
target units such as <filename>runlevel3.target</filename> exist
which are used by the SysV runlevel compatibility code in systemd.
See
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>
for details).</para>
</refsect1>
<refsect1>
<title>Automatic Dependencies</title>
<para>Unless <varname>DefaultDependencies=</varname> is set to
<option>no</option>, target units will implicitly complement all
configured dependencies of type <varname>Wants=</varname>,
<varname>Requires=</varname> with dependencies of type
<varname>After=</varname>, unless an ordering dependency of any
kind between the target and the respective other unit is already
in place. Note that this behaviour is disabled if either unit has
<varname>DefaultDependencies=no</varname>.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>