man: finish systemd.unit.5
This commit is contained in:
Lennart Poettering
parent
436c44a5d6
commit
11e299550e
|
|
@ -48,15 +48,15 @@
|
|||
</refnamediv>
|
||||
|
||||
<refsynopsisdiv>
|
||||
<para><filename>systemd.service</filename></para>
|
||||
<para><filename>systemd.socket</filename></para>
|
||||
<para><filename>systemd.device</filename></para>
|
||||
<para><filename>systemd.mount</filename></para>
|
||||
<para><filename>systemd.automount</filename></para>
|
||||
<para><filename>systemd.swap</filename></para>
|
||||
<para><filename>systemd.target</filename></para>
|
||||
<para><filename>systemd.path</filename></para>
|
||||
<para><filename>systemd.timer</filename></para>
|
||||
<para><filename>systemd.service</filename>,
|
||||
<filename>systemd.socket</filename>,
|
||||
<filename>systemd.device</filename>,
|
||||
<filename>systemd.mount</filename>,
|
||||
<filename>systemd.automount</filename>,
|
||||
<filename>systemd.swap</filename>,
|
||||
<filename>systemd.target</filename>,
|
||||
<filename>systemd.path</filename>,
|
||||
<filename>systemd.timer</filename></para>
|
||||
</refsynopsisdiv>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -66,15 +66,74 @@
|
|||
about a service, a socket, a device, a mount point, an
|
||||
automount point, a swap file or partition, a start-up
|
||||
target, a file system path or a timer controlled and
|
||||
supervised by <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. The syntax is inspired by XDG
|
||||
<filename>.desktop</filename> files, which are in turn
|
||||
inspired by Microsoft Windows <filename>.ini</filename>
|
||||
files.</para>
|
||||
supervised by
|
||||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. The
|
||||
syntax is inspired by <ulink
|
||||
url="http://standards.freedesktop.org/desktop-entry-spec/latest/">XDG
|
||||
Desktop Entry Specificiation</ulink> <filename>.desktop</filename> files, which are in turn
|
||||
inspired by Microsoft Windows
|
||||
<filename>.ini</filename> files.</para>
|
||||
|
||||
<para>This man pages lists the common configuration
|
||||
options of the all unit types. These options need to
|
||||
be configured either in the [Unit] resp. [Install]
|
||||
be configured in the [Unit] resp. [Install]
|
||||
section of the unit files.</para>
|
||||
|
||||
<para>In addition to the generic [Unit] and [Install]
|
||||
sections described here each unit should have a
|
||||
type-specific section, e.g. [Service] for a service
|
||||
unit. See the respective man pages for more
|
||||
information.</para>
|
||||
|
||||
<para>Unit files may contain additional options on top
|
||||
of those listed here. If systemd encounters an unknown
|
||||
option it will write a warning log message but
|
||||
continue loading the unit. If an option is prefixed
|
||||
with <option>X-</option> it is ignored completely by
|
||||
systemd. Applications may use this to include
|
||||
additional information in the unit files.</para>
|
||||
|
||||
<para>Boolean arguments used in unit files can be
|
||||
written in various forms. For positive settings the
|
||||
strings <option>1</option>, <option>yes</option>,
|
||||
<option>true</option> and <option>on</option> are
|
||||
equivalent. For negative settings the strings
|
||||
<option>0</option>, <option>no</option>,
|
||||
<option>false</option> and <option>off</option> are
|
||||
equivalent.</para>
|
||||
|
||||
<para>Empty lines and lines starting with # or ; are
|
||||
ignored. This may be used for commenting.</para>
|
||||
|
||||
<para>If a line starts with <option>.include</option>
|
||||
followed by a file name the specified file will be
|
||||
read as if its contents where listed in place of the
|
||||
<option>.include</option> directive.</para>
|
||||
|
||||
<para>Along with a unit file
|
||||
<filename>foo.service</filename> a directory
|
||||
<filename>foo.service.wants/</filename> may exist. All
|
||||
units symlinked from such a directory are implicitly
|
||||
added as dependencies of type
|
||||
<varname>Wanted=</varname> to the unit. This is useful
|
||||
to hook units into the start-up of other units,
|
||||
without having to modify their unit configuration
|
||||
files. For details about the semantics of
|
||||
<varname>Wanted=</varname> see below. The preferred
|
||||
way to create symlinks in the
|
||||
<filename>.wants/</filename> directory of a service is
|
||||
with the
|
||||
<citerefentry><refentrytitle>systemd-install</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
tool which reads information from the [Install]
|
||||
section of unit files. (See below.)</para>
|
||||
|
||||
<para>Note that while systemd offers a flexible
|
||||
dependency system between units it is recommended to
|
||||
use this functionality only sparsely and instead rely
|
||||
on techniques such as bus-based or socket-based
|
||||
activation which makes dependencies implicit, which
|
||||
both results in a simpler and more flexible
|
||||
system.</para>
|
||||
</refsect1>
|
||||
|
||||
<refsect1>
|
||||
|
|
@ -97,13 +156,23 @@
|
|||
that this option is different from the
|
||||
<varname>Alias=</varname> option from
|
||||
the [Install] section mentioned
|
||||
below. See below for details</para>
|
||||
below. See below for details.</para>
|
||||
</listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Description=</varname></term>
|
||||
<listitem><para>A free-form string
|
||||
describing the unit. This is intended for use
|
||||
in UIs wanting to show
|
||||
descriptive information along with the
|
||||
unit name.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Requires=</varname></term>
|
||||
|
||||
<listitem><para>Requirement
|
||||
<listitem><para>Configures requirement
|
||||
dependencies on other units. If this
|
||||
units get activated the units listed
|
||||
here will be activated as well. If one
|
||||
|
|
@ -112,9 +181,224 @@
|
|||
be deactivated. This option may be
|
||||
specified more than once, in which
|
||||
case requirement dependencies for all
|
||||
listed names are created.</para>
|
||||
</listitem>
|
||||
listed names are created. Note that
|
||||
requirement dependencies do not
|
||||
influence the order in which services
|
||||
are started or stopped. This has to be
|
||||
configured independently with the
|
||||
<varname>After=</varname> or
|
||||
<varname>Before=</varname> options. If
|
||||
a unit
|
||||
<filename>foo.service</filename>
|
||||
requires a unit
|
||||
<filename>bar.service</filename> as
|
||||
configured with
|
||||
<varname>Requires=</varname> and no
|
||||
ordering is configured with
|
||||
<varname>After=</varname> or
|
||||
<varname>Before=</varname>, then both
|
||||
units will be started simultaneously
|
||||
and without any delay between them if
|
||||
<filename>foo.service</filename> is
|
||||
activated. Often it is a better choice
|
||||
to use <varname>Wants=</varname>
|
||||
instead of
|
||||
<varname>Requires=</varname> in order
|
||||
to achieve a system that is more
|
||||
robust when dealing with failing
|
||||
services.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>RequiresOverridable=</varname></term>
|
||||
|
||||
<listitem><para>Similar to
|
||||
<varname>Requires=</varname>.
|
||||
Dependencies listed in
|
||||
<varname>RequiresOverridable=</varname>
|
||||
which cannot be fulfilled or fail to
|
||||
start are ignored iff the startup was
|
||||
explicitly requested by the user. If
|
||||
the start-up was pulled in indirectly
|
||||
by some dependency or automatic
|
||||
start-up of units that is not
|
||||
requested by the user this dependency
|
||||
must be fulfilled and otherwise the
|
||||
transaction fails. Hence, this option
|
||||
may be used to configure dependencies
|
||||
that are normally honoured unless the
|
||||
user explicitly starts up the unit, in
|
||||
which case whether they failed or not
|
||||
is irrelevant.</para></listitem>
|
||||
|
||||
</varlistentry>
|
||||
<varlistentry>
|
||||
<term><varname>Requisite=</varname></term>
|
||||
<term><varname>RequisiteOverridable=</varname></term>
|
||||
|
||||
<listitem><para>Similar to
|
||||
<varname>Requires=</varname>
|
||||
resp. <varname>RequiresOverridable=</varname>. However,
|
||||
if a unit listed here is not started
|
||||
already it will not be started and the
|
||||
transaction fails
|
||||
immediately.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Wants=</varname></term>
|
||||
|
||||
<listitem><para>A weaker version of
|
||||
<varname>Requires=</varname>. A unit
|
||||
listed in this option will be started
|
||||
if the configuring unit is. However,
|
||||
it the listed unit fails to start up
|
||||
or cannot be added to the transaction
|
||||
this has no impact on the validity of
|
||||
the transaction as a whole. This is
|
||||
the recommended way to hook start-up
|
||||
of one unit to the start-up of another
|
||||
unit. Note that dependencies of this
|
||||
type may also be configured outside of
|
||||
the unit configuration file by
|
||||
adding a symlink to a
|
||||
<filename>.wants/</filename> directory
|
||||
accompanying the unit file. For
|
||||
details see above.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Conflicts=</varname></term>
|
||||
|
||||
<listitem><para>Configures negative
|
||||
requirement dependencies. If a unit
|
||||
that 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></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Before=</varname></term>
|
||||
<term><varname>After=</varname></term>
|
||||
|
||||
<listitem><para>Configures ordering
|
||||
dependencies between units. If a unit
|
||||
<filename>foo.service</filename>
|
||||
contains a setting
|
||||
<option>Before=bar.service</option>
|
||||
and both units are being started
|
||||
<filename>bar.service</filename>'s
|
||||
start-up is delayed until
|
||||
<filename>foo.service</filename> is
|
||||
started up. Note that this setting is
|
||||
independent of and orthogonal to the
|
||||
requirement dependencies as configured
|
||||
by <varname>Requires=</varname>. It is
|
||||
a common pattern to include a unit
|
||||
name in both the
|
||||
<varname>After=</varname> and
|
||||
<varname>Requires=</varname> option in
|
||||
which case the unit listed will be
|
||||
started before the unit that is
|
||||
configured with these options. This
|
||||
option may be specified more than
|
||||
once, in which case ordering
|
||||
dependencies for all listed names are
|
||||
created. <varname>After=</varname> is
|
||||
the inverse of
|
||||
<varname>Before=</varname>, i.e. while
|
||||
<varname>After=</varname> ensures that
|
||||
the configured unit is started after
|
||||
the listed unit finished starting up,
|
||||
<varname>Before=</varname> ensures the
|
||||
opposite, i.e. that the configured
|
||||
unit is fully started up before the
|
||||
listed unit is started. Note that when
|
||||
two units with an ordering dependency
|
||||
between them are shut down, the
|
||||
inverse of of the start-up order is
|
||||
applied. i.e. if a unit is configured
|
||||
with <varname>After=</varname> on
|
||||
another unit, the former is stopped
|
||||
before the latter if both are shut
|
||||
down. If one unit with an ordering
|
||||
dependency on another unit is shut
|
||||
down while the latter is started up,
|
||||
the shut down is ordered before the
|
||||
start-up regardless whether the
|
||||
ordering dependency is actually of
|
||||
type <varname>After=</varname> or
|
||||
<varname>Before=</varname>. If two
|
||||
units have no ordering dependencies
|
||||
between them they are shut down
|
||||
resp. started up simultaneously, and
|
||||
no ordering takes
|
||||
place. </para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>RecursiveStop=</varname></term>
|
||||
|
||||
<listitem><para>Takes a boolean
|
||||
argument. If <option>true</option> and
|
||||
the unit stops without this being
|
||||
requested by the user all units
|
||||
depending on it will be stopped as
|
||||
well. (e.g. if a service exits or
|
||||
crashes on its own behalf, units using
|
||||
it will be stopped) Note that normally
|
||||
if a unit stops without user request
|
||||
units depending on it will not be
|
||||
terminated. Only if the user requested
|
||||
shutdown of a unit all units depending
|
||||
on the unit will be shut down as well
|
||||
and at the same time. Defaults to
|
||||
<option>false</option>.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>StopWhenUnneeded=</varname></term>
|
||||
|
||||
<listitem><para>Takes a boolean
|
||||
argument. If <option>true</option>
|
||||
this unit will be stopped when it is
|
||||
no longer used. Note that in order to
|
||||
minimize the work to be executed
|
||||
systemd will by default not stop units
|
||||
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>OnlyByDependency=</varname></term>
|
||||
|
||||
<listitem><para>Takes a boolean
|
||||
argument. If <option>true</option>
|
||||
this unit may only be activated
|
||||
indirectly. In this case explicit
|
||||
start-up requested by the user is
|
||||
denied, however if it is started as
|
||||
dependency of another unit start-up
|
||||
will succeed. This is mostly a safety
|
||||
feature to ensure that the user does
|
||||
not accidently activate units that are
|
||||
not intended to be activated
|
||||
explicitly. This option defaults to
|
||||
<option>false</option>.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
</variablelist>
|
||||
|
||||
<para>Unit file may include a [Install] section, which
|
||||
|
|
@ -123,7 +407,7 @@
|
|||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
during runtime. It is used exclusively by the
|
||||
<citerefentry><refentrytitle>systemd-install</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||||
during installation of a unit:</para>
|
||||
tool during installation of a unit:</para>
|
||||
|
||||
<variablelist>
|
||||
<varlistentry>
|
||||
|
|
@ -148,18 +432,52 @@
|
|||
unconditionally if the unit is
|
||||
loaded. The names from
|
||||
<varname>Alias=</varname> apply only
|
||||
if the unit is actually installed with
|
||||
the <command>systemd-install</command>
|
||||
if the unit has actually been
|
||||
installed with the
|
||||
<command>systemd-install</command>
|
||||
tool. Also, if systemd searches for a
|
||||
unit, it will discover symlinked alias
|
||||
names, but not names configured only
|
||||
with <varname>Names=</varname>. It is
|
||||
a common pattern to list a name in both
|
||||
options. In this case, a unit will be
|
||||
active under all names if installed,
|
||||
but also if not installed but
|
||||
requested
|
||||
explicitly.</para></listitem>
|
||||
names as configured with
|
||||
<varname>Alias=</varname>, but not
|
||||
names configured with
|
||||
<varname>Names=</varname> only. It is
|
||||
a common pattern to list a name in
|
||||
both options. In this case, a unit
|
||||
will be active under all names if
|
||||
installed, but also if not installed
|
||||
but requested explicitly under its
|
||||
main name.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>WantedBy=</varname></term>
|
||||
|
||||
<listitem><para>Installs a symlink in
|
||||
the <filename>.wants/</filename>
|
||||
subdirectory for a unit. This has the
|
||||
effect that when the listed unit name
|
||||
is activated the unit listing it is
|
||||
activated
|
||||
to. <command>WantedBy=foo.service</command>
|
||||
in a service
|
||||
<filename>bar.service</filename> is
|
||||
mostly equivalent to
|
||||
<command>Alias=foo.service.wants/bar.service</command>
|
||||
in the same file.</para></listitem>
|
||||
</varlistentry>
|
||||
|
||||
<varlistentry>
|
||||
<term><varname>Also=</varname></term>
|
||||
|
||||
<listitem><para>Additional units to
|
||||
install when this unit is
|
||||
installed. If the user requests
|
||||
installation of a unit with this
|
||||
option configured
|
||||
<command>systemd-install</command>
|
||||
will automatically install units
|
||||
listed in this option as
|
||||
well.</para></listitem>
|
||||
</varlistentry>
|
||||
</variablelist>
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue