<refnamediv>
<refname>systemd.unit</refname>
- <refpurpose>systemd unit configuration files</refpurpose>
+ <refpurpose>Unit configuration</refpurpose>
</refnamediv>
<refsynopsisdiv>
<entry>User home directory</entry>
<entry>This is the home directory of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
</row>
+ <row>
+ <entry><literal>%s</literal></entry>
+ <entry>User shell</entry>
+ <entry>This is the shell of the configured user of the unit, or (if none is set) the user running the systemd instance.</entry>
+ </row>
+ <row>
+ <entry><literal>%m</literal></entry>
+ <entry>Machine ID</entry>
+ <entry>The machine ID of the running system, formatted as string. See <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.</entry>
+ </row>
+ <row>
+ <entry><literal>%b</literal></entry>
+ <entry>Boot ID</entry>
+ <entry>The boot ID of the running system, formatted as string. See <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.</entry>
+ </row>
+ <row>
+ <entry><literal>%H</literal></entry>
+ <entry>Host name</entry>
+ <entry>The host name of the running system.</entry>
+ </row>
</tbody>
</tgroup>
</table>
<varname>Requires=</varname> in order
to achieve a system that is more
robust when dealing with failing
- services.</para></listitem>
+ services.</para>
+
+ <para>Note that dependencies of this
+ type may also be configured outside of
+ the unit configuration file by
+ adding a symlink to a
+ <filename>.requires/</filename> directory
+ accompanying the unit file. For
+ details see above.</para></listitem>
</varlistentry>
<varlistentry>
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
+ unit.</para>
+
+ <para>Note that dependencies of this
type may also be configured outside of
the unit configuration file by
adding a symlink to a
<listitem><para>Configures requirement
dependencies, very similar in style to
<varname>Requires=</varname>, however
- in addition to this behaviour it also
+ in addition to this behavior it also
declares that this unit is stopped
when any of the units listed suddenly
disappears. Units can suddenly,
systemd.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>PartOf=</varname></term>
+
+ <listitem><para>Configures dependencies
+ similar to <varname>Requires=</varname>,
+ but limited to stopping and restarting
+ of units. When systemd stops or restarts
+ the units listed here, the action is
+ propagated to this unit.
+ Note that this is a one way dependency -
+ changes to this unit do not affect the
+ listed units.
+ </para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>Conflicts=</varname></term>
<term><varname>RequiresMountsFor=</varname></term>
<listitem><para>Takes a space
- separated list of paths. Automatically
+ separated list of absolute paths. Automatically
adds dependencies of type
<varname>Requires=</varname> and
<varname>After=</varname> for all
<term><varname>ConditionPathIsMountPoint=</varname></term>
<term><varname>ConditionPathIsReadWrite=</varname></term>
<term><varname>ConditionDirectoryNotEmpty=</varname></term>
+ <term><varname>ConditionFileNotEmpty=</varname></term>
<term><varname>ConditionFileIsExecutable=</varname></term>
<term><varname>ConditionKernelCommandLine=</varname></term>
<term><varname>ConditionVirtualization=</varname></term>
<term><varname>ConditionSecurity=</varname></term>
<term><varname>ConditionCapability=</varname></term>
+ <term><varname>ConditionHost=</varname></term>
<term><varname>ConditionNull=</varname></term>
<listitem><para>Before starting a unit
verify that the specified condition is
- true. With
+ true. If it is not true the starting
+ of the unit will be skipped, however
+ all ordering dependencies of it are
+ still respected. A failing condition
+ will not result in the unit being
+ moved into a failure state. The
+ condition is checked at the time the
+ queued start job is to be
+ executed.</para>
+
+ <para>With
<varname>ConditionPathExists=</varname>
- a file existence condition can be
+ a file existence condition is
checked before a unit is started. If
the specified absolute path name does
- not exist, startup of a unit will not
- actually happen, however the unit is
- still useful for ordering purposes in
- this case. The condition is checked at
- the time the queued start job is to be
- executed. If the absolute path name
- passed to
+ not exist the condition will
+ fail. If the absolute path name passed
+ to
<varname>ConditionPathExists=</varname>
is prefixed with an exclamation mark
- (!), the test is negated, and the unit
+ ('!'), the test is negated, and the unit
is only started if the path does not
- exist.
- <varname>ConditionPathExistsGlob=</varname>
- works in a similar way, but checks for
- the existence of at least one file or
- directory matching the specified
- globbing
- pattern. <varname>ConditionPathIsDirectory=</varname>
+ 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. <varname>ConditionPathIsSymbolicLink=</varname>
+ directory.</para>
+
+ <para><varname>ConditionPathIsSymbolicLink=</varname>
is similar to
<varname>ConditionPathExists=</varname>
but verifies whether a certain path
exists and is a symbolic
- link. <varname>ConditionPathIsMountPoint=</varname>
+ link.</para>
+
+ <para><varname>ConditionPathIsMountPoint=</varname>
is similar to
<varname>ConditionPathExists=</varname>
but verifies whether a certain path
exists and is a mount
- point. <varname>ConditionPathIsReadWrite=</varname>
+ point.</para>
+
+ <para><varname>ConditionPathIsReadWrite=</varname>
is similar to
<varname>ConditionPathExists=</varname>
but verifies whether the underlying
- file system is read and writable
+ file system is readable and writable
(i.e. not mounted
- read-only). <varname>ConditionFileIsExecutable=</varname>
+ read-only).</para>
+
+ <para><varname>ConditionDirectoryNotEmpty=</varname>
is similar to
<varname>ConditionPathExists=</varname>
but verifies whether a certain path
- exists, is a regular file and marked
- executable.
- <varname>ConditionDirectoryNotEmpty=</varname>
+ 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 is a non-empty
- directory. Similarly
+ exists and refers to a regular file
+ with a non-zero size.</para>
+
+ <para><varname>ConditionFileIsExecutable=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists, is a regular file and marked
+ executable.</para>
+
+ <para>Similar,
<varname>ConditionKernelCommandLine=</varname>
may be used to check whether a
specific kernel command line option is
exclamation mark unset). The argument
must either be a single word, or an
assignment (i.e. two words, separated
- by the equality sign). In the former
+ '='). 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. <varname>ConditionVirtualization=</varname>
+ matching.</para>
+
+ <para><varname>ConditionVirtualization=</varname>
may be used to check whether the
system is executed in a virtualized
environment and optionally test
any virtualized environment, or one of
<varname>vm</varname> and
<varname>container</varname> to test
- against a specific type of
+ against a generic type of
virtualization solution, or one of
<varname>qemu</varname>,
<varname>kvm</varname>,
virtualization technologies are nested
only the innermost is considered. The
test may be negated by prepending an
- exclamation mark.
- <varname>ConditionSecurity=</varname>
+ exclamation mark.</para>
+
+ <para><varname>ConditionSecurity=</varname>
may be used to check whether the given
security module is enabled on the
system. Currently the only recognized
value is <varname>selinux</varname>.
The test may be negated by prepending
an exclamation
- mark. <varname>ConditionCapability=</varname>
+ 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
for details). Pass a capability name
such as <literal>CAP_MKNOD</literal>,
possibly prefixed with an exclamation
- mark to negate the check. Finally,
+ mark to negate the check.</para>
+
+ <para><varname>ConditionHost=</varname>
+ may be used to match against the
+ host name or machine ID of the
+ host. This either takes a host name
+ string (optionally with shell style
+ globs) which is tested against the
+ locally set host name as returned by
+ <citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+ or a machine ID formatted as string
+ (see
+ <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
+ The test may be negated by prepending
+ an exclamation mark.</para>
+
+ <para>Finally,
<varname>ConditionNull=</varname> may
be used to add a constant condition
check value to the unit. It takes a
boolean argument. If set to
<varname>false</varname> the condition
will always fail, otherwise
- succeed. If multiple conditions are
+ succeed.</para>
+
+ <para>If multiple conditions are
specified the unit will be executed if
all of them apply (i.e. a logical AND
is applied). Condition checks can be
~ianmdlvl / elogind.git / blobdiff