</refnamediv>
<refsynopsisdiv>
- <para><filename>systemd.service</filename></para>
+ <para><filename><replaceable>service</replaceable>.service</filename></para>
</refsynopsisdiv>
<refsect1>
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
which define the execution environment the commands
are executed in, and in
- <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
which define the way the processes of the service are
- terminated.</para>
+ terminated, and in
+ <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which configure control group settings for the
+ processes of the service.</para>
<para>Unless <varname>DefaultDependencies=</varname>
is set to <option>false</option>, service units will
script. This is useful for compatibility with
SysV. Note that this compatibility is quite
comprehensive but not 100%. For details about the
- incomptibilities see the <ulink
+ incomp
atibilities see the <ulink
url="http://www.freedesktop.org/wiki/Software/systemd/Incompatibilities">Incompatibilities
with SysV</ulink> document.
</para>
options specific to the <literal>[Service]</literal>
section of service units are the following:</para>
- <variablelist>
+ <variablelist class='unit-directives'>
<varlistentry>
<term><varname>Type=</varname></term>
<para>If set to
<option>simple</option> (the default
value if <varname>BusName=</varname>
- is not specified) it is expected that
+ is not specified), it is expected that
the process configured with
<varname>ExecStart=</varname> is the
main process of the service. In this
mode, if the process offers
functionality to other processes on
- the system its communication channels
+ the system, its communication channels
should be installed before the daemon
is started up (e.g. sockets set up by
systemd, via socket activation), as
starting follow-up units.</para>
<para>If set to
- <option>forking</option> it is
+ <option>forking</option>, it is
expected that the process configured
with <varname>ExecStart=</varname>
will call <function>fork()</function>
as part of its start-up. The parent process is
expected to exit when start-up is
complete and all communication
- channels set up. The child continues
+ channels are set up. The child continues
to run as the main daemon
- process. This is the behaviour of
+ process. This is the behavior of
traditional UNIX daemons. If this
setting is used, it is recommended to
also use the
soon as the parent process
exits.</para>
- <para>Behaviour of
+ <para>Behavior of
<option>oneshot</option> is similar
to <option>simple</option>, however
it is expected that the process has to
is particularly useful for this type
of service.</para>
- <para>Behaviour of
+ <para>Behavior of
<option>dbus</option> is similar to
<option>simple</option>, however it is
expected that the daemon acquires a
<varname>BusName=</varname> is
specified.</para>
- <para>Behaviour of
+ <para>Behavior of
<option>notify</option> is similar to
<option>simple</option>, however it is
expected that the daemon sends a
starting up. systemd will proceed
starting follow-up units after this
notification message has been sent. If
- this option is used
+ this option is used,
<varname>NotifyAccess=</varname> (see
below) should be set to open access to
the notification socket provided by
systemd. If
<varname>NotifyAccess=</varname> is
not set, it will be implicitly set to
- <option>main</option>.</para>
+ <option>main</option>. Note that
+ currently
+ <varname>Type=</varname><option>notify</option>
+ will not work if used in combination with
+ <varname>PrivateNetwork=</varname><option>yes</option>.</para>
- <para>Behaviour of
+ <para>Behavior of
<option>idle</option> is very similar
to <option>simple</option>, however
- actual execution of a the service
+ actual execution of the service
binary is delayed until all jobs are
dispatched. This may be used to avoid
interleaving of output of shell
<listitem><para>Takes a boolean value
that specifies whether systemd should
try to guess the main PID of a service
- should if it cannot be determined
+ if it cannot be determined
reliably. This option is ignored
unless <option>Type=forking</option>
is set and <option>PIDFile=</option>
guessing algorithm might come to
incorrect conclusions if a daemon
consists of more than one process. If
- the main PID cannot be determined
+ the main PID cannot be determined,
failure detection and automatic
restarting of a service will not work
reliably. Defaults to
<term><varname>BusName=</varname></term>
<listitem><para>Takes a D-Bus bus
- name, where this service is reachable
+ name, that this service is reachable
as. This option is mandatory for
services where
<varname>Type=</varname> is set to
<varlistentry>
<term><varname>ExecStart=</varname></term>
- <listitem><para>Takes a command line
- that is executed when this service
- shall be started up. The first token
- of the command line must be an
- absolute file name, then followed by
- arguments for the process. It is
- mandatory to set this option for all
- services. This option may not be
- specified more than once, except when
+ <listitem><para>Commands with their
+ arguments that are executed when this
+ service is started. The first
+ argument must be an absolute path
+ name.</para>
+
+ <para>When <varname>Type</varname> is
+ not <option>oneshot</option>, only one
+ command may be given. When
<varname>Type=oneshot</varname> is
- used in which case more than one
- <varname>ExecStart=</varname> line is
- accepted which are then invoked one by
- one, sequentially in the order they
- appear in the unit file.</para>
-
- <para>Optionally, if the absolute file
- name is prefixed with
- <literal>@</literal>, the second token
- will be passed as
- <literal>argv[0]</literal> to the
- executed process, followed by the
- further arguments specified. If the
- first token is prefixed with
- <literal>-</literal> an exit code of
- the command normally considered a
- failure (i.e. non-zero exit status or
- abnormal exit due to signal) is ignored
- and considered success. If both
- <literal>-</literal> and
- <literal>@</literal> are used for the
- same command the former must precede
- the latter. Unless
+ used, more than one command may be
+ specified. Multiple command lines may
+ be concatenated in a single directive,
+ by separating them with semicolons
+ (these semicolons must be passed as
+ separate words). Alternatively, this
+ directive may be specified more than
+ once with the same effect. However,
+ the latter syntax is not recommended
+ for compatibility with parsers
+ suitable for XDG
+ <filename>.desktop</filename> files.
+ Lone semicolons may be escaped as
+ <literal>\;</literal>. If the empty
+ string is assigned to this option, the
+ list of commands to start is reset,
+ prior assignments of this option will
+ have no effect.</para>
+
+ <para>If more than one command is
+ specified, the commands are invoked
+ one by one sequentially in the order
+ they appear in the unit file. If one
+ of the commands fails (and is not
+ prefixed with <literal>-</literal>),
+ other lines are not executed and the
+ unit is considered failed.</para>
+
+ <para>Unless
<varname>Type=forking</varname> is
set, the process started via this
command line will be considered the
- main process of the daemon. The
- command line accepts % specifiers as
+ main process of the daemon.</para>
+
+ <para>The command line accepts
+ <literal>%</literal> specifiers as
described in
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note
+ that the first argument of the command
+ line (i.e. the program to execute) may
+ not include specifiers.</para>
- <para>On top of that basic environment
- variable substitution is
- supported. Use
+ <para>Basic environment variable
+ substitution is supported. Use
<literal>${FOO}</literal> as part of a
- word, or as word of its own on the
+ word, or as a word of its own on the
command line, in which case it will be
replaced by the value of the
environment variable including all
word on the command line, in which
case it will be replaced by the value
of the environment variable split up
- at whitespace, resulting in no or more
- arguments. Note that the first
+ at whitespace, resulting in zero or
+ more arguments. To pass literal dollar sign
+ use <literal>$$</literal>. Note that the first
argument (i.e. the program to execute)
- may not be a variable, and must be a
- literal and absolute path
- name.</para></listitem>
+ may not be a variable, since it must
+ be a literal and absolute path
+ name.</para>
+
+ <para>Optionally, if the absolute file
+ name is prefixed with
+ <literal>@</literal>, the second token
+ will be passed as
+ <literal>argv[0]</literal> to the
+ executed process, followed by the
+ further arguments specified. If the
+ absolute filename is prefixed with
+ <literal>-</literal>, an exit code of
+ the command normally considered a
+ failure (i.e. non-zero exit status or
+ abnormal exit due to signal) is ignored
+ and considered success. If both
+ <literal>-</literal> and
+ <literal>@</literal> are used, they
+ can appear in either order.</para>
+
+ <para>Note that this setting does not
+ directly support shell command
+ lines. If shell command lines are to
+ be used, they need to be passed
+ explicitly to a shell implementation
+ of some kind. Example:</para>
+ <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'
+ </programlisting>
+
+ <para>For services run by a user
+ instance of systemd the special
+ environment variable
+ <varname>$MANAGERPID</varname> is set
+ to the PID of the systemd
+ instance.</para>
+ </listitem>
</varlistentry>
<varlistentry>
<term><varname>ExecStartPre=</varname></term>
<term><varname>ExecStartPost=</varname></term>
<listitem><para>Additional commands
- that are executed before (resp. after)
+ that are executed before or after
the command in
- <varname>ExecStart=</varname>. Multiple
- command lines may be concatenated in a
- single directive, by separating them
- by semicolons (these semicolons must
- be passed as separate words). In that
- case, the commands are executed one
- after the other,
- serially. Alternatively, these
- directives may be specified more than
- once with the same effect. However,
- the latter syntax is not recommended
- for compatibility with parsers
- suitable for XDG
- <filename>.desktop</filename> files.
- Use of these settings is
- optional. Specifier and environment
- variable substitution is
- supported.</para></listitem>
+ <varname>ExecStart=</varname>, respectively.
+ Syntax is the same as for
+ <varname>ExecStart=</varname>, except
+ that multiple command lines are allowed
+ and the commands are executed one
+ after the other, serially.</para>
+
+ <para>If any of those commands (not
+ prefixed with <literal>-</literal>)
+ fail, the rest are not executed and
+ the unit is considered failed.</para>
+ </listitem>
</varlistentry>
<varlistentry>
trigger a configuration reload in the
service. This argument takes multiple
command lines, following the same
- scheme as pointed out for
- <varname>ExecStartPre=</varname>
+ scheme as described for
+ <varname>ExecStart=</varname>
above. Use of this setting is
optional. Specifier and environment
variable substitution is supported
here following the same scheme as for
- <varname>ExecStart=</varname>. One
- special environment variable is set:
- if known <literal>$MAINPID</literal> is
- set to the main process of the
- daemon, and may be used for command
- lines like the following:
- <command>/bin/kill -HUP
- $MAINPID</command>.</para></listitem>
+ <varname>ExecStart=</varname>.</para>
+
+ <para>One additional special
+ environment variables is set: if known
+ <varname>$MAINPID</varname> is set to
+ the main process of the daemon, and
+ may be used for command lines like the
+ following:</para>
+
+ <programlisting>/bin/kill -HUP $MAINPID</programlisting>
+ </listitem>
</varlistentry>
<varlistentry>
stop the service started via
<varname>ExecStart=</varname>. This
argument takes multiple command lines,
- following the same scheme as pointed
- out for
- <varname>ExecStartPre=</varname>
+ following the same scheme as described
+ for <varname>ExecStart=</varname>
above. Use of this setting is
optional. All processes remaining for
a service after the commands
<varname>KillMode=</varname> setting
(see
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
- this option is not specified the
+ this option is not specified, the
process is terminated right-away when
service stop is requested. Specifier
and environment variable substitution
is supported (including
- <literal>$MAINPID</literal>, see
+ <varname>$MAINPID</varname>, see
above).</para></listitem>
</varlistentry>
<term><varname>ExecStopPost=</varname></term>
<listitem><para>Additional commands
that are executed after the service
- was stopped using the commands
- configured in
- <varname>ExecStop=</varname>. This
+ was stopped. This includes cases where
+ the commands configured in
+ <varname>ExecStop=</varname> were used,
+ where the service does not have any
+ <varname>ExecStop=</varname> defined, or
+ where the service exited unexpectedly. This
argument takes multiple command lines,
- following the same scheme as pointed
- out for
- <varname>ExecStartPre</varname>. Use
+ following the same scheme as described
+ for <varname>ExecStart</varname>. Use
of these settings is
optional. Specifier and environment
variable substitution is
wait for stop. If a service is asked
to stop but does not terminate in the
specified time, it will be terminated
- forcibly via SIGTERM, and after
+ forcibly via <constant>SIGTERM</constant>, and after
another delay of this time with
- SIGKILL (See
+ <constant>SIGKILL</constant> (See
<varname>KillMode=</varname>
in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
Takes a unit-less value in seconds, or a
<varlistentry>
<term><varname>WatchdogSec=</varname></term>
<listitem><para>Configures the
- watchdog timeout for a service. This
- is activated when the start-up is
+ watchdog timeout for a service. The
+ watchdog is activated when the start-up is
completed. The service must call
<citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
regularly with "WATCHDOG=1" (i.e. the
"keep-alive ping"). If the time
between two such calls is larger than
- the configured time then the service
+ the configured time, then the service
is placed in a failure state. By
setting <varname>Restart=</varname> to
<option>on-failure</option> or
- <option>always</option> the service
+ <option>always</option>, the service
will be automatically restarted. The
time configured here will be passed to
the executed service process in the
daemons to automatically enable the
keep-alive pinging logic if watchdog
support is enabled for the service. If
- this option is used
+ this option is used,
<varname>NotifyAccess=</varname> (see
below) should be set to open access to
the notification socket provided by
<varlistentry>
<term><varname>Restart=</varname></term>
<listitem><para>Configures whether the
- main service process shall be
- restarted when it exits. Takes one of
+ service shall be restarted when the
+ service process exits, is killed,
+ or a timeout is reached. The service
+ process may be the main service
+ process, but also one of the processes
+ specified with
+ <varname>ExecStartPre=</varname>,
+ <varname>ExecStartPost=</varname>,
+ <varname>ExecStopPre=</varname>,
+ <varname>ExecStopPost=</varname>, or
+ <varname>ExecReload=</varname>.
+ When the death of the process is a
+ result of systemd operation (e.g. service
+ stop or restart), the service will not be
+ restarted. Timeouts include missing
+ the watchdog "keep-alive ping"
+ deadline and a service start, reload,
+ and stop operation timeouts.</para>
+
+ <para>Takes one of
<option>no</option>,
<option>on-success</option>,
<option>on-failure</option>,
- <option>on-abort</option> or
+ <option>on-watchdog</option>,
+ <option>on-abort</option>, or
<option>always</option>. If set to
- <option>no</option> (the default) the
- service will not be restarted when it
- exits. If set to
- <option>on-success</option> it will be
- restarted only when it exited cleanly,
- i.e. terminated with an exit code of
- 0. If set to
- <option>on-failure</option> it will be
- restarted only when it exited with an
- exit code not equalling 0, when
- terminated by a signal (including on
+ <option>no</option> (the default), the
+ service will not be restarted. If set to
+ <option>on-success</option>, it will be
+ restarted only when the service process
+ exits cleanly.
+ In this context, a clean exit means
+ an exit code of 0, or one of the signals
+ <constant>SIGHUP</constant>, <constant>SIGINT</constant>, <constant>SIGTERM</constant>, or <constant>SIGPIPE</constant>, and
+ additionally, exit statuses and signals
+ specified in <varname>SuccessExitStatus=</varname>.
+ If set to <option>on-failure</option>,
+ the service will be restarted when the
+ process exits with an nonzero exit code,
+ is terminated by a signal (including on
core dump), when an operation (such as
- service reload) times out or when the
- configured watchdog timeout is
- triggered. If set to
- <option>on-abort</option> it will be
- restarted only if it exits due to
- reception of an uncaught signal
- (including on core dump). If set to
- <option>always</option> the service
+ service reload) times out, and when the
+ configured watchdog timeout is triggered.
+ If set to
+ <option>on-abort</option>, the service
+ will be restarted only if the service
+ process exits due to an uncaught
+ signal not specified as a clean exit
+ status.
+ If set to
+ <option>on-watchdog</option>, the service
+ will be restarted only if the watchdog
+ timeout for the service expires.
+ If set to
+ <option>always</option>, the service
will be restarted regardless whether
it exited cleanly or not, got
terminated abnormally by a signal or
- hit a timeout.</para></listitem>
+ hit a timeout.</para>
+
+ <para>In addition to the above settings,
+ the service will not be restarted if the
+ exit code or signal is specified in
+ <varname>RestartPreventExitStatus=</varname>
+ (see below).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SuccessExitStatus=</varname></term>
+ <listitem><para>Takes a list of exit
+ status definitions that when returned
+ by the main service process will be
+ considered successful termination, in
+ addition to the normal successful exit
+ code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
+ <constant>SIGTERM</constant> and <constant>SIGPIPE</constant>. Exit status
+ definitions can either be numeric exit
+ codes or termination signal names,
+ separated by spaces. Example:
+ <literal>SuccessExitStatus=1 2 8
+ <constant>SIGKILL</constant></literal>, ensures that exit
+ codes 1, 2, 8 and the termination
+ signal <constant>SIGKILL</constant> are considered clean
+ service terminations. This option may
+ appear more than once in which case
+ the list of successful exit statuses
+ is merged. If the empty string is
+ assigned to this option, the list is
+ reset, all prior assignments of this
+ option will have no
+ effect.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RestartPreventExitStatus=</varname></term>
+ <listitem><para>Takes a list of exit
+ status definitions that when returned
+ by the main service process will
+ prevent automatic service restarts
+ regardless of the restart setting
+ configured with
+ <varname>Restart=</varname>. Exit
+ status definitions can either be
+ numeric exit codes or termination
+ signal names, and are separated by
+ spaces. Defaults to the empty list, so
+ that by default no exit status is
+ excluded from the configured restart
+ logic. Example:
+ <literal>RestartPreventExitStatus=1 6
+ SIGABRT</literal>, ensures that exit
+ codes 1 and 6 and the termination
+ signal SIGABRT will not result in
+ automatic service restarting. This
+ option may appear more than once in
+ which case the list of restart preventing
+ statuses is merged. If the empty
+ string is assigned to this option, the
+ list is reset, all prior assignments
+ of this option will have no
+ effect.</para></listitem>
</varlistentry>
<varlistentry>
<option>none</option> (the default),
<option>main</option> or
<option>all</option>. If
- <option>none</option> no daemon status
+ <option>none</option>, no daemon status
updates are accepted from the service
processes, all status update messages
- are ignored. If <option>main</option>
+ are ignored. If <option>main</option>,
only service updates sent from the
main process of the service are
- accepted. If <option>all</option> all
+ accepted. If <option>all</option>, all
services updates from all members of
the service's control group are
accepted. This option should be set to
open access to the notification socket
when using
<varname>Type=notify</varname> or
- <varname>WatchdogUsec=</varname> (see
+ <varname>WatchdogSec=</varname> (see
above). If those options are used but
- <varname>NotifyAccess=</varname> not
- configured it will be implicitly set
+ <varname>NotifyAccess=</varname> is not
+ configured, it will be implicitly set
to
<option>main</option>.</para></listitem>
</varlistentry>
same time. Also note that a different
service may be activated on incoming
traffic than inherits the sockets. Or
- in other words: The
+ in other words: the
<varname>Service=</varname> setting of
<filename>.socket</filename> units
- doesn't have to match the inverse of the
- <varname>Sockets=</varname> setting of
- the <filename>.service</filename> it
- refers to.</para></listitem>
+ does not have to match the inverse of
+ the <varname>Sockets=</varname>
+ setting of the
+ <filename>.service</filename> it
+ refers to.</para>
+
+ <para>This option may appear more than
+ once, in which case the list of socket
+ units is merged. If the empty string
+ is assigned to this option, the list of
+ sockets is reset, all prior uses of
+ this setting will have no
+ effect.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>StartLimitBurst=</varname></term>
<listitem><para>Configure service
- start rate limiting. By default
+ start rate limiting. By default,
services which are started more often
than 5 times within 10s are not
permitted to start any more times
until the 10s interval ends. With
- these two options this rate limiting
+ these two options, this rate limiting
may be modified. Use
<varname>StartLimitInterval=</varname>
to configure the checking interval
for compatibility reasons and should not be used in
newly written service files.</para>
- <variablelist>
+ <variablelist class='unit-directives'>
<varlistentry>
<term><varname>SysVStartPriority=</varname></term>
<listitem><para>Set the SysV start
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff