<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
<term><varname>ExecStart=</varname></term>
<listitem><para>Commands with their
arguments that are executed when this
- service is started.
- </para>
+ service is started. The first
+ argument must be an absolute path
+ name.</para>
- <para>When
+ <para>When <varname>Type</varname> is
+ not <option>oneshot</option>, only one
+ command may be given. When
<varname>Type=oneshot</varname> is
used, more than one command may be
specified. Multiple command lines may
for compatibility with parsers
suitable for XDG
<filename>.desktop</filename> files.
- The commands are invoked one by one
- sequentially in the order they appear
- in the unit file. When
- <varname>Type</varname> is not
- <option>oneshot</option>, only one
- command may be given. Lone semicolons
- may be escaped as
- '<literal>\;</literal>'. If the empty
+ 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
main process of the daemon.</para>
<para>The command line accepts
- '<literal>%</literal>' specifiers as
+ <literal>%</literal> specifiers as
described in
<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>${FOO}</literal> as part of a
word, or as a word of its own on the
command line, in which case it will be
word on the command line, in which
case it will be replaced by the value
of the environment variable split up
- at whitespace, resulting in no or more
- arguments. Note that the first
+ at whitespace, resulting in zero or
+ more arguments. Note that the first
argument (i.e. the program to execute)
- may not be a variable, and must be a
- literal and absolute path
+ may not be a variable, since it must
+ be a literal and absolute path
name.</para>
<para>Optionally, if the absolute file
name is prefixed with
- '<literal>@</literal>', the second token
+ <literal>@</literal>, the second token
will be passed as
<literal>argv[0]</literal> to the
executed process, followed by the
further arguments specified. If the
- absolute file name is prefixed with
- '<literal>-</literal>' an exit code of
+ absolute filename is prefixed with
+ <literal>-</literal> an exit code of
the command normally considered a
failure (i.e. non-zero exit status or
abnormal exit due to signal) is ignored
and considered success. If both
- '<literal>-</literal>' and
- '<literal>@</literal>' are used they
+ <literal>-</literal> and
+ <literal>@</literal> are used they
can appear in either order.</para>
<para>Note that this setting does not
lines. If shell command lines are to
be used they need to be passed
explicitly to a shell implementation
- of some kind. Example:
- <literal>ExecStart=/bin/sh -c 'dmesg | tac'</literal></para>
+ of some kind. Example:</para>
+ <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'
+ </programlisting>
<para>For services run by a user
instance of systemd the special
environment variable
- <literal>MANAGERPID</literal> is set
+ <varname>$MANAGERPID</varname> is set
to the PID of the systemd
instance.</para>
</listitem>
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>
optional. Specifier and environment
variable substitution is supported
here following the same scheme as for
- <varname>ExecStart=</varname>. One
- additional special environment
- variables is set: if known
- <literal>$MAINPID</literal> is set to
+ <varname>ExecStart=</varname>.</para>
+
+ <para>One additional special
+ environment variables is set: if known
+ <varname>$MAINPID</varname> is set to
the main process of the daemon, and
may be used for command lines like the
- following: <command>/bin/kill -HUP
- $MAINPID</command>.</para></listitem>
+ following:</para>
+
+ <programlisting>/bin/kill -HUP $MAINPID</programlisting>
+ </listitem>
</varlistentry>
<varlistentry>
service stop is requested. Specifier
and environment variable substitution
is supported (including
- <literal>$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 doesn't have any
+ <varname>ExecStop=</varname> defined, or
+ where the service exited unexpectedly. This
argument takes multiple command lines,
following the same scheme as described
for <varname>ExecStart</varname>. Use
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
<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-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
+ service will not be restarted. 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 equaling 0, when
- terminated by a signal (including on
+ 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
+ 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>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>
by the main service process will be
considered successful termination, in
addition to the normal successful exit
- code 0 and the signals SIGHUP, SIGINT,
- SIGTERM and SIGPIPE. Exit status
+ 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, and
- are separated by spaces. Example:
- "<literal>SuccessExitStatus=1 2 8
- SIGKILL</literal>", ensures that 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 SIGKILL are considered clean
+ 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
that by default no exit status is
excluded from the configured restart
logic. Example:
- "<literal>RestartPreventExitStatus=1 6
- SIGABRT</literal>", ensures that exit
+ <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
<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.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>
~ianmdlvl / elogind.git / blobdiff