chiark / gitweb /
service: add FailureAction= option
[elogind.git] / man / systemd.service.xml
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3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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9   Copyright 2010 Lennart Poettering
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24
25 <refentry id="systemd.service">
26         <refentryinfo>
27                 <title>systemd.service</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>systemd.service</refentrytitle>
42                 <manvolnum>5</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemd.service</refname>
47                 <refpurpose>Service unit configuration</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <para><filename><replaceable>service</replaceable>.service</filename></para>
52         </refsynopsisdiv>
53
54         <refsect1>
55                 <title>Description</title>
56
57                 <para>A unit configuration file whose name ends in
58                 <filename>.service</filename> encodes information
59                 about a process controlled and supervised by
60                 systemd.</para>
61
62                 <para>This man page lists the configuration options
63                 specific to this unit type. See
64                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
65                 for the common options of all unit configuration
66                 files. The common configuration items are configured
67                 in the generic <literal>[Unit]</literal> and
68                 <literal>[Install]</literal> sections. The service
69                 specific configuration options are configured in the
70                 <literal>[Service]</literal> section.</para>
71
72                 <para>Additional options are listed in
73                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
74                 which define the execution environment the commands
75                 are executed in, and in
76                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
77                 which define the way the processes of the service are
78                 terminated, and in
79                 <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
80                 which configure resource control settings for the
81                 processes of the service.</para>
82
83                 <para>Unless <varname>DefaultDependencies=</varname>
84                 is set to <option>false</option>, service units will
85                 implicitly have dependencies of type
86                 <varname>Requires=</varname> and
87                 <varname>After=</varname> on
88                 <filename>basic.target</filename> as well as
89                 dependencies of type <varname>Conflicts=</varname> and
90                 <varname>Before=</varname> on
91                 <filename>shutdown.target</filename>. These ensure
92                 that normal service units pull in basic system
93                 initialization, and are terminated cleanly prior to
94                 system shutdown. Only services involved with early
95                 boot or late system shutdown should disable this
96                 option.</para>
97
98                 <para>If a service is requested under a certain name
99                 but no unit configuration file is found, systemd looks
100                 for a SysV init script by the same name (with the
101                 <filename>.service</filename> suffix removed) and
102                 dynamically creates a service unit from that
103                 script. This is useful for compatibility with
104                 SysV. Note that this compatibility is quite
105                 comprehensive but not 100%. For details about the
106                 incompatibilities, see the <ulink
107                 url="http://www.freedesktop.org/wiki/Software/systemd/Incompatibilities">Incompatibilities
108                 with SysV</ulink> document.
109                 </para>
110         </refsect1>
111
112         <refsect1>
113                 <title>Options</title>
114
115                 <para>Service files must include a
116                 <literal>[Service]</literal> section, which carries
117                 information about the service and the process it
118                 supervises. A number of options that may be used in
119                 this section are shared with other unit types. These
120                 options are documented in
121                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
122                 and
123                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
124                 options specific to the <literal>[Service]</literal>
125                 section of service units are the following:</para>
126
127                 <variablelist class='unit-directives'>
128                         <varlistentry>
129                                 <term><varname>Type=</varname></term>
130
131                                 <listitem><para>Configures the process
132                                 start-up type for this service
133                                 unit. One of <option>simple</option>,
134                                 <option>forking</option>,
135                                 <option>oneshot</option>,
136                                 <option>dbus</option>,
137                                 <option>notify</option> or
138                                 <option>idle</option>.</para>
139
140                                 <para>If set to
141                                 <option>simple</option> (the default
142                                 value if neither
143                                 <varname>Type=</varname> nor
144                                 <varname>BusName=</varname> are
145                                 specified), it is expected that the
146                                 process configured with
147                                 <varname>ExecStart=</varname> is the
148                                 main process of the service. In this
149                                 mode, if the process offers
150                                 functionality to other processes on
151                                 the system, its communication channels
152                                 should be installed before the daemon
153                                 is started up (e.g. sockets set up by
154                                 systemd, via socket activation), as
155                                 systemd will immediately proceed
156                                 starting follow-up units.</para>
157
158                                 <para>If set to
159                                 <option>forking</option>, it is
160                                 expected that the process configured
161                                 with <varname>ExecStart=</varname>
162                                 will call <function>fork()</function>
163                                 as part of its start-up. The parent process is
164                                 expected to exit when start-up is
165                                 complete and all communication
166                                 channels are set up. The child continues
167                                 to run as the main daemon
168                                 process. This is the behavior of
169                                 traditional UNIX daemons. If this
170                                 setting is used, it is recommended to
171                                 also use the
172                                 <varname>PIDFile=</varname> option, so
173                                 that systemd can identify the main
174                                 process of the daemon. systemd will
175                                 proceed with starting follow-up units
176                                 as soon as the parent process
177                                 exits.</para>
178
179                                 <para>Behavior of
180                                 <option>oneshot</option> is similar
181                                 to <option>simple</option>; however,
182                                 it is expected that the process has to
183                                 exit before systemd starts follow-up
184                                 units. <varname>RemainAfterExit=</varname>
185                                 is particularly useful for this type
186                                 of service.</para>
187
188                                 <para>Behavior of
189                                 <option>dbus</option> is similar to
190                                 <option>simple</option>; however, it is
191                                 expected that the daemon acquires a
192                                 name on the D-Bus bus, as configured
193                                 by
194                                 <varname>BusName=</varname>. systemd
195                                 will proceed with starting follow-up
196                                 units after the D-Bus bus name has been
197                                 acquired. Service units with this
198                                 option configured implicitly gain
199                                 dependencies on the
200                                 <filename>dbus.socket</filename>
201                                 unit. This type is the default if
202                                 <varname>BusName=</varname> is
203                                 specified.</para>
204
205                                 <para>Behavior of
206                                 <option>notify</option> is similar to
207                                 <option>simple</option>; however, it is
208                                 expected that the daemon sends a
209                                 notification message via
210                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
211                                 or an equivalent call when it has finished
212                                 starting up. systemd will proceed with
213                                 starting follow-up units after this
214                                 notification message has been sent. If
215                                 this option is used,
216                                 <varname>NotifyAccess=</varname> (see
217                                 below) should be set to open access to
218                                 the notification socket provided by
219                                 systemd. If
220                                 <varname>NotifyAccess=</varname> is
221                                 not set, it will be implicitly set to
222                                 <option>main</option>. Note that
223                                 currently
224                                 <varname>Type=</varname><option>notify</option>
225                                 will not work if used in combination with
226                                 <varname>PrivateNetwork=</varname><option>yes</option>.</para>
227
228                                 <para>Behavior of
229                                 <option>idle</option> is very similar
230                                 to <option>simple</option>; however,
231                                 actual execution of the service
232                                 binary is delayed until all jobs are
233                                 dispatched. This may be used to avoid
234                                 interleaving of output of shell
235                                 services with the status output on the
236                                 console.</para>
237                                 </listitem>
238                         </varlistentry>
239
240                         <varlistentry>
241                                 <term><varname>RemainAfterExit=</varname></term>
242
243                                 <listitem><para>Takes a boolean value
244                                 that specifies whether the service
245                                 shall be considered active even when
246                                 all its processes exited. Defaults to
247                                 <option>no</option>.</para>
248                                 </listitem>
249                         </varlistentry>
250
251                         <varlistentry>
252                                 <term><varname>GuessMainPID=</varname></term>
253
254                                 <listitem><para>Takes a boolean value
255                                 that specifies whether systemd should
256                                 try to guess the main PID of a service
257                                 if it cannot be determined
258                                 reliably. This option is ignored
259                                 unless <option>Type=forking</option>
260                                 is set and <option>PIDFile=</option>
261                                 is unset because for the other types
262                                 or with an explicitly configured PID
263                                 file, the main PID is always known. The
264                                 guessing algorithm might come to
265                                 incorrect conclusions if a daemon
266                                 consists of more than one process. If
267                                 the main PID cannot be determined,
268                                 failure detection and automatic
269                                 restarting of a service will not work
270                                 reliably. Defaults to
271                                 <option>yes</option>.</para>
272                                 </listitem>
273                         </varlistentry>
274
275                         <varlistentry>
276                                 <term><varname>PIDFile=</varname></term>
277
278                                 <listitem><para>Takes an absolute file
279                                 name pointing to the PID file of this
280                                 daemon. Use of this option is
281                                 recommended for services where
282                                 <varname>Type=</varname> is set to
283                                 <option>forking</option>. systemd will
284                                 read the PID of the main process of
285                                 the daemon after start-up of the
286                                 service. systemd will not write to the
287                                 file configured here.</para>
288                                 </listitem>
289                         </varlistentry>
290
291                         <varlistentry>
292                                 <term><varname>BusName=</varname></term>
293
294                                 <listitem><para>Takes a D-Bus bus
295                                 name that this service is reachable
296                                 as. This option is mandatory for
297                                 services where
298                                 <varname>Type=</varname> is set to
299                                 <option>dbus</option>, but its use
300                                 is otherwise recommended if the process
301                                 takes a name on the D-Bus bus.</para>
302                                 </listitem>
303                         </varlistentry>
304
305                         <varlistentry>
306                                 <term><varname>ExecStart=</varname></term>
307                                 <listitem><para>Commands with their
308                                 arguments that are executed when this
309                                 service is started. For each of the
310                                 specified commands, the first argument
311                                 must be an absolute and literal path
312                                 to an executable.</para>
313
314                                 <para>When <varname>Type</varname> is
315                                 not <option>oneshot</option>, only one
316                                 command may be given. When
317                                 <varname>Type=oneshot</varname> is
318                                 used, more than one command may be
319                                 specified. Multiple command lines may
320                                 be concatenated in a single directive
321                                 by separating them with semicolons
322                                 (these semicolons must be passed as
323                                 separate words). Alternatively, this
324                                 directive may be specified more than
325                                 once with the same effect.
326                                 Lone semicolons may be escaped as
327                                 <literal>\;</literal>. If the empty
328                                 string is assigned to this option, the
329                                 list of commands to start is reset,
330                                 prior assignments of this option will
331                                 have no effect.</para>
332
333                                 <para>Each command line is split on
334                                 whitespace, with the first item being
335                                 the command to execute, and the
336                                 subsequent items being the arguments.
337                                 Double quotes ("...") and single
338                                 quotes ('...') may be used, in which
339                                 case everything until the next
340                                 matching quote becomes part of the
341                                 same argument. Quotes themselves are
342                                 removed after parsing. In addition, a
343                                 trailing backslash
344                                 (<literal>\</literal>) may be used to
345                                 merge lines. This syntax is intended
346                                 to be very similar to shell syntax,
347                                 but only the meta-characters and
348                                 expansions described in the following
349                                 paragraphs are understood.
350                                 Specifically, redirection using
351                                 <literal>&lt;</literal>,
352                                 <literal>&lt;&lt;</literal>,
353                                 <literal>&gt;</literal>, and
354                                 <literal>&gt;&gt;</literal>, pipes
355                                 using <literal>|</literal>, and
356                                 running programs in the background
357                                 using <literal>&amp;</literal>
358                                 and <emphasis>other elements of shell
359                                 syntax are not supported</emphasis>.
360                                 </para>
361
362                                 <para>If more than one command is
363                                 specified, the commands are invoked
364                                 sequentially in the order they appear
365                                 in the unit file. If one of the
366                                 commands fails (and is not prefixed
367                                 with <literal>-</literal>), other lines
368                                 are not executed, and the unit is
369                                 considered failed.</para>
370
371                                 <para>Unless
372                                 <varname>Type=forking</varname> is
373                                 set, the process started via this
374                                 command line will be considered the
375                                 main process of the daemon.</para>
376
377                                 <para>The command line accepts
378                                 <literal>%</literal> specifiers as
379                                 described in
380                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
381                                 Note that the first argument of the
382                                 command line (i.e. the program to
383                                 execute) may not include
384                                 specifiers.</para>
385
386                                 <para>Basic environment variable
387                                 substitution is supported. Use
388                                 <literal>${FOO}</literal> as part of a
389                                 word, or as a word of its own, on the
390                                 command line, in which case it will be
391                                 replaced by the value of the
392                                 environment variable including all
393                                 whitespace it contains, resulting in a
394                                 single argument. Use
395                                 <literal>$FOO</literal> as a separate
396                                 word on the command line, in which
397                                 case it will be replaced by the value
398                                 of the environment variable split at
399                                 whitespace, resulting in zero or more
400                                 arguments. To pass a literal dollar
401                                 sign, use <literal>$$</literal>.
402                                 Variables whose value is not known at
403                                 expansion time are treated as empty
404                                 strings. Note that the first argument
405                                 (i.e. the program to execute) may not
406                                 be a variable.</para>
407
408                                 <para>Variables to be used in this
409                                 fashion may be defined through
410                                 <varname>Environment=</varname> and
411                                 <varname>EnvironmentFile=</varname>.
412                                 In addition, variables listed in the
413                                 section "Environment variables in
414                                 spawned processes" in
415                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
416                                 which are considered "static
417                                 configuration", may be used (this includes
418                                 e.g. <varname>$USER</varname>, but not
419                                 <varname>$TERM</varname>).</para>
420
421                                 <para>Optionally, if the absolute file
422                                 name is prefixed with
423                                 <literal>@</literal>, the second token
424                                 will be passed as
425                                 <literal>argv[0]</literal> to the
426                                 executed process, followed by the
427                                 further arguments specified. If the
428                                 absolute filename is prefixed with
429                                 <literal>-</literal>, an exit code of
430                                 the command normally considered a
431                                 failure (i.e. non-zero exit status or
432                                 abnormal exit due to signal) is ignored
433                                 and considered success. If both
434                                 <literal>-</literal> and
435                                 <literal>@</literal> are used, they
436                                 can appear in either order.</para>
437
438                                 <para>Note that this setting does not
439                                 directly support shell command
440                                 lines. If shell command lines are to
441                                 be used, they need to be passed
442                                 explicitly to a shell implementation
443                                 of some kind. Example:</para>
444                                 <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'</programlisting>
445                                 <para>Example:</para>
446                                 <programlisting>ExecStart=/bin/echo one ; /bin/echo "two two"</programlisting>
447                                 <para>This will execute
448                                 <command>/bin/echo</command> two
449                                 times, each time with one argument:
450                                 <literal>one</literal> and
451                                 <literal>two two</literal>,
452                                 respectively. Because two commands are
453                                 specified,
454                                 <varname>Type=oneshot</varname> must
455                                 be used.</para>
456
457                                 <para>Example:</para>
458                                 <programlisting>ExecStart=/bin/echo / &gt;/dev/null &amp; \; \
459 /bin/ls</programlisting>
460                                 <para>This will execute
461                                 <command>/bin/echo</command> with five
462                                 arguments: <literal>/</literal>,
463                                 <literal>&gt;/dev/null</literal>,
464                                 <literal>&amp;</literal>,
465                                 <literal>;</literal>, and
466                                 <literal>/bin/ls</literal>.</para>
467
468                                 <para>Example:</para>
469                                 <programlisting>Environment="ONE=one" 'TWO=two two'
470 ExecStart=/bin/echo $ONE $TWO ${TWO}</programlisting>
471                                 <para>This will execute
472                                 <command>/bin/echo</command> with four
473                                 arguments: <literal>one</literal>,
474                                 <literal>two</literal>,
475                                 <literal>two</literal>, and
476                                 <literal>two two</literal>.</para>
477                               </listitem>
478                         </varlistentry>
479
480                         <varlistentry>
481                                 <term><varname>ExecStartPre=</varname></term>
482                                 <term><varname>ExecStartPost=</varname></term>
483                                 <listitem><para>Additional commands
484                                 that are executed before or after
485                                 the command in
486                                 <varname>ExecStart=</varname>, respectively.
487                                 Syntax is the same as for
488                                 <varname>ExecStart=</varname>, except
489                                 that multiple command lines are allowed
490                                 and the commands are executed one
491                                 after the other, serially.</para>
492
493                                 <para>If any of those commands (not
494                                 prefixed with <literal>-</literal>)
495                                 fail, the rest are not executed and
496                                 the unit is considered failed.</para>
497                                 </listitem>
498                         </varlistentry>
499
500                         <varlistentry>
501                                 <term><varname>ExecReload=</varname></term>
502                                 <listitem><para>Commands to execute to
503                                 trigger a configuration reload in the
504                                 service. This argument takes multiple
505                                 command lines, following the same
506                                 scheme as described for
507                                 <varname>ExecStart=</varname>
508                                 above. Use of this setting is
509                                 optional. Specifier and environment
510                                 variable substitution is supported
511                                 here following the same scheme as for
512                                 <varname>ExecStart=</varname>.</para>
513
514                                 <para>One additional, special
515                                 environment variable is set: if known,
516                                 <varname>$MAINPID</varname> is set to
517                                 the main process of the daemon, and
518                                 may be used for command lines like the
519                                 following:</para>
520
521                                 <programlisting>/bin/kill -HUP $MAINPID</programlisting>
522                                 </listitem>
523                         </varlistentry>
524
525                         <varlistentry>
526                                 <term><varname>ExecStop=</varname></term>
527                                 <listitem><para>Commands to execute to
528                                 stop the service started via
529                                 <varname>ExecStart=</varname>. This
530                                 argument takes multiple command lines,
531                                 following the same scheme as described
532                                 for <varname>ExecStart=</varname>
533                                 above. Use of this setting is
534                                 optional. After the commands configured
535                                 in this option are run, all processes
536                                 remaining for a service are
537                                 terminated according to the
538                                 <varname>KillMode=</varname> setting
539                                 (see
540                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
541                                 this option is not specified, the
542                                 process is terminated immediately when
543                                 service stop is requested. Specifier
544                                 and environment variable substitution
545                                 is supported (including
546                                 <varname>$MAINPID</varname>, see
547                                 above).</para></listitem>
548                         </varlistentry>
549
550                         <varlistentry>
551                                 <term><varname>ExecStopPost=</varname></term>
552                                 <listitem><para>Additional commands
553                                 that are executed after the service
554                                 was stopped. This includes cases where
555                                 the commands configured in
556                                 <varname>ExecStop=</varname> were used,
557                                 where the service does not have any
558                                 <varname>ExecStop=</varname> defined, or
559                                 where the service exited unexpectedly. This
560                                 argument takes multiple command lines,
561                                 following the same scheme as described
562                                 for <varname>ExecStart</varname>. Use
563                                 of these settings is
564                                 optional. Specifier and environment
565                                 variable substitution is
566                                 supported.</para></listitem>
567                         </varlistentry>
568
569                         <varlistentry>
570                                 <term><varname>RestartSec=</varname></term>
571                                 <listitem><para>Configures the time to
572                                 sleep before restarting a service (as
573                                 configured with
574                                 <varname>Restart=</varname>). Takes a
575                                 unit-less value in seconds, or a time
576                                 span value such as "5min
577                                 20s". Defaults to
578                                 100ms.</para></listitem>
579                         </varlistentry>
580
581                         <varlistentry>
582                                 <term><varname>TimeoutStartSec=</varname></term>
583                                 <listitem><para>Configures the time to
584                                 wait for start-up. If a
585                                 daemon service does not signal
586                                 start-up completion within the
587                                 configured time, the service will be
588                                 considered failed and will be shut
589                                 down again.
590                                 Takes a unit-less value in seconds, or a
591                                 time span value such as "5min
592                                 20s". Pass <literal>0</literal> to
593                                 disable the timeout logic. Defaults to
594                                 <varname>TimeoutStartSec=</varname> from
595                                 the manager configuration file, except
596                                 when <varname>Type=oneshot</varname> is
597                                 used, in which case the timeout
598                                 is disabled by default.
599                                 </para></listitem>
600                         </varlistentry>
601
602                         <varlistentry>
603                                 <term><varname>TimeoutStopSec=</varname></term>
604                                 <listitem><para>Configures the time to
605                                 wait for stop. If a service is asked
606                                 to stop, but does not terminate in the
607                                 specified time, it will be terminated
608                                 forcibly via <constant>SIGTERM</constant>,
609                                 and after another timeout of equal duration
610                                 with <constant>SIGKILL</constant> (see
611                                 <varname>KillMode=</varname>
612                                 in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
613                                 Takes a unit-less value in seconds, or a
614                                 time span value such as "5min
615                                 20s". Pass <literal>0</literal> to disable
616                                 the timeout logic. Defaults to
617                                 <varname>TimeoutStartSec=</varname> from the
618                                 manager configuration file.
619                                 </para></listitem>
620                         </varlistentry>
621
622                         <varlistentry>
623                                 <term><varname>TimeoutSec=</varname></term>
624                                 <listitem><para>A shorthand for configuring
625                                 both <varname>TimeoutStartSec=</varname>
626                                 and <varname>TimeoutStopSec=</varname>
627                                 to the specified value.
628                                 </para></listitem>
629                         </varlistentry>
630
631                         <varlistentry>
632                                 <term><varname>WatchdogSec=</varname></term>
633                                 <listitem><para>Configures the
634                                 watchdog timeout for a service. The
635                                 watchdog is activated when the start-up is
636                                 completed. The service must call
637                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
638                                 regularly with <literal>WATCHDOG=1</literal>
639                                 (i.e. the "keep-alive ping"). If the time
640                                 between two such calls is larger than
641                                 the configured time, then the service
642                                 is placed in a failed state. By
643                                 setting <varname>Restart=</varname> to
644                                 <option>on-failure</option> or
645                                 <option>always</option>, the service
646                                 will be automatically restarted. The
647                                 time configured here will be passed to
648                                 the executed service process in the
649                                 <varname>WATCHDOG_USEC=</varname>
650                                 environment variable. This allows
651                                 daemons to automatically enable the
652                                 keep-alive pinging logic if watchdog
653                                 support is enabled for the service. If
654                                 this option is used,
655                                 <varname>NotifyAccess=</varname> (see
656                                 below) should be set to open access to
657                                 the notification socket provided by
658                                 systemd. If
659                                 <varname>NotifyAccess=</varname> is
660                                 not set, it will be implicitly set to
661                                 <option>main</option>. Defaults to 0,
662                                 which disables this
663                                 feature.</para></listitem>
664                         </varlistentry>
665
666                         <varlistentry>
667                                 <term><varname>Restart=</varname></term>
668                                 <listitem><para>Configures whether the
669                                 service shall be restarted when the
670                                 service process exits, is killed,
671                                 or a timeout is reached. The service
672                                 process may be the main service
673                                 process, but it may also be one of the
674                                 processes specified with
675                                 <varname>ExecStartPre=</varname>,
676                                 <varname>ExecStartPost=</varname>,
677                                 <varname>ExecStop=</varname>,
678                                 <varname>ExecStopPost=</varname>, or
679                                 <varname>ExecReload=</varname>.
680                                 When the death of the process is a
681                                 result of systemd operation (e.g. service
682                                 stop or restart), the service will not be
683                                 restarted. Timeouts include missing
684                                 the watchdog "keep-alive ping"
685                                 deadline and a service start, reload,
686                                 and stop operation timeouts.</para>
687
688                                 <para>Takes one of
689                                 <option>no</option>,
690                                 <option>on-success</option>,
691                                 <option>on-failure</option>,
692                                 <option>on-watchdog</option>,
693                                 <option>on-abort</option>, or
694                                 <option>always</option>. If set to
695                                 <option>no</option> (the default), the
696                                 service will not be restarted. If set to
697                                 <option>on-success</option>, it will be
698                                 restarted only when the service process
699                                 exits cleanly.
700                                 In this context, a clean exit means
701                                 an exit code of 0, or one of the signals
702                                 <constant>SIGHUP</constant>,
703                                 <constant>SIGINT</constant>,
704                                 <constant>SIGTERM</constant>,
705                                 or <constant>SIGPIPE</constant>, and
706                                 additionally, exit statuses and signals
707                                 specified in <varname>SuccessExitStatus=</varname>.
708                                 If set to <option>on-failure</option>,
709                                 the service will be restarted when the
710                                 process exits with a non-zero exit code,
711                                 is terminated by a signal (including on
712                                 core dump), when an operation (such as
713                                 service reload) times out, and when the
714                                 configured watchdog timeout is triggered.
715                                 If set to
716                                 <option>on-abort</option>, the service
717                                 will be restarted only if the service
718                                 process exits due to an uncaught
719                                 signal not specified as a clean exit
720                                 status.
721                                 If set to
722                                 <option>on-watchdog</option>, the service
723                                 will be restarted only if the watchdog
724                                 timeout for the service expires.
725                                 If set to
726                                 <option>always</option>, the service
727                                 will be restarted regardless of whether
728                                 it exited cleanly or not, got
729                                 terminated abnormally by a signal, or
730                                 hit a timeout.</para>
731
732                                 <para>In addition to the above settings,
733                                 the service will not be restarted if the
734                                 exit code or signal is specified in
735                                 <varname>RestartPreventExitStatus=</varname>
736                                 (see below).</para></listitem>
737                         </varlistentry>
738
739                         <varlistentry>
740                                 <term><varname>SuccessExitStatus=</varname></term>
741                                 <listitem><para>Takes a list of exit
742                                 status definitions that when returned
743                                 by the main service process will be
744                                 considered successful termination, in
745                                 addition to the normal successful exit
746                                 code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
747                                 <constant>SIGTERM</constant>, and <constant>SIGPIPE</constant>. Exit status
748                                 definitions can either be numeric exit
749                                 codes or termination signal names,
750                                 separated by spaces. For example:
751                                 <programlisting>SuccessExitStatus=1 2 8 <constant>SIGKILL</constant></programlisting>
752                                 ensures that exit codes 1, 2, 8 and
753                                 the termination signal
754                                 <constant>SIGKILL</constant> are
755                                 considered clean service terminations.
756                                 </para>
757
758                                 <para>Note that if a process has a
759                                 signal handler installed and exits by
760                                 calling
761                                 <citerefentry><refentrytitle>_exit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
762                                 in response to a signal, the
763                                 information about the signal is lost.
764                                 Programs should instead perform cleanup and kill themselves with the same signal instead. See
765                                 <ulink url="http://www.cons.org/cracauer/sigint.html">Proper handling of SIGINT/SIGQUIT — How to be a proper program</ulink>.</para>
766
767                                 <para>This option may appear more than once,
768                                 in which case the list of successful
769                                 exit statuses is merged. If the empty
770                                 string is assigned to this option, the
771                                 list is reset, all prior assignments
772                                 of this option will have no
773                                 effect.</para></listitem>
774                         </varlistentry>
775
776                         <varlistentry>
777                                 <term><varname>RestartPreventExitStatus=</varname></term>
778                                 <listitem><para>Takes a list of exit
779                                 status definitions that when returned
780                                 by the main service process will
781                                 prevent automatic service restarts,
782                                 regardless of the restart setting
783                                 configured with
784                                 <varname>Restart=</varname>. Exit
785                                 status definitions can either be
786                                 numeric exit codes or termination
787                                 signal names, and are separated by
788                                 spaces. Defaults to the empty list, so
789                                 that, by default, no exit status is
790                                 excluded from the configured restart
791                                 logic. Example:
792                                 <literal>RestartPreventExitStatus=1 6
793                                 SIGABRT</literal>, ensures that exit
794                                 codes 1 and 6 and the termination
795                                 signal <constant>SIGABRT</constant> will
796                                 not result in automatic service
797                                 restarting. This
798                                 option may appear more than once, in
799                                 which case the list of restart-preventing
800                                 statuses is merged. If the empty
801                                 string is assigned to this option, the
802                                 list is reset and all prior assignments
803                                 of this option will have no
804                                 effect.</para></listitem>
805                         </varlistentry>
806
807                         <varlistentry>
808                                 <term><varname>PermissionsStartOnly=</varname></term>
809                                 <listitem><para>Takes a boolean
810                                 argument. If true, the permission-related
811                                 execution options, as
812                                 configured with
813                                 <varname>User=</varname> and similar
814                                 options (see
815                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
816                                 for more information), are only applied
817                                 to the process started with
818                                 <varname>ExecStart=</varname>, and not
819                                 to the various other
820                                 <varname>ExecStartPre=</varname>,
821                                 <varname>ExecStartPost=</varname>,
822                                 <varname>ExecReload=</varname>,
823                                 <varname>ExecStop=</varname>, and
824                                 <varname>ExecStopPost=</varname>
825                                 commands. If false, the setting is
826                                 applied to all configured commands the
827                                 same way. Defaults to
828                                 false.</para></listitem>
829                         </varlistentry>
830
831                         <varlistentry>
832                                 <term><varname>RootDirectoryStartOnly=</varname></term>
833                                 <listitem><para>Takes a boolean
834                                 argument. If true, the root directory,
835                                 as configured with the
836                                 <varname>RootDirectory=</varname>
837                                 option (see
838                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
839                                 for more information), is only applied
840                                 to the process started with
841                                 <varname>ExecStart=</varname>, and not
842                                 to the various other
843                                 <varname>ExecStartPre=</varname>,
844                                 <varname>ExecStartPost=</varname>,
845                                 <varname>ExecReload=</varname>,
846                                 <varname>ExecStop=</varname>, and
847                                 <varname>ExecStopPost=</varname>
848                                 commands. If false, the setting is
849                                 applied to all configured commands the
850                                 same way. Defaults to
851                                 false.</para></listitem>
852                         </varlistentry>
853
854                         <varlistentry>
855                                 <term><varname>NonBlocking=</varname></term>
856                                 <listitem><para>Set the
857                                 <constant>O_NONBLOCK</constant> flag
858                                 for all file descriptors passed via
859                                 socket-based activation. If true, all
860                                 file descriptors >= 3 (i.e. all except
861                                 stdin, stdout, and stderr) will have
862                                 the <constant>O_NONBLOCK</constant> flag
863                                 set and hence are in
864                                 non-blocking mode. This option is only
865                                 useful in conjunction with a socket
866                                 unit, as described in
867                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
868                                 to false.</para></listitem>
869                         </varlistentry>
870
871                         <varlistentry>
872                                 <term><varname>NotifyAccess=</varname></term>
873                                 <listitem><para>Controls access to the
874                                 service status notification socket, as
875                                 accessible via the
876                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
877                                 call. Takes one of
878                                 <option>none</option> (the default),
879                                 <option>main</option> or
880                                 <option>all</option>. If
881                                 <option>none</option>, no daemon status
882                                 updates are accepted from the service
883                                 processes, all status update messages
884                                 are ignored. If <option>main</option>,
885                                 only service updates sent from the
886                                 main process of the service are
887                                 accepted. If <option>all</option>, all
888                                 services updates from all members of
889                                 the service's control group are
890                                 accepted. This option should be set to
891                                 open access to the notification socket
892                                 when using
893                                 <varname>Type=notify</varname> or
894                                 <varname>WatchdogSec=</varname> (see
895                                 above). If those options are used but
896                                 <varname>NotifyAccess=</varname> is not
897                                 configured, it will be implicitly set
898                                 to
899                                 <option>main</option>.</para></listitem>
900                         </varlistentry>
901
902                         <varlistentry>
903                                 <term><varname>Sockets=</varname></term>
904                                 <listitem><para>Specifies the name of
905                                 the socket units this service shall
906                                 inherit the sockets from when the
907                                 service is started. Normally it
908                                 should not be necessary to use this
909                                 setting as all sockets whose unit
910                                 shares the same name as the service
911                                 (ignoring the different suffix of course)
912                                 are passed to the spawned
913                                 process.</para>
914
915                                 <para>Note that the same socket may be
916                                 passed to multiple processes at the
917                                 same time. Also note that a different
918                                 service may be activated on incoming
919                                 traffic than that which inherits the
920                                 sockets. Or in other words: the
921                                 <varname>Service=</varname> setting of
922                                 <filename>.socket</filename> units
923                                 does not have to match the inverse of
924                                 the <varname>Sockets=</varname>
925                                 setting of the
926                                 <filename>.service</filename> it
927                                 refers to.</para>
928
929                                 <para>This option may appear more than
930                                 once, in which case the list of socket
931                                 units is merged. If the empty string
932                                 is assigned to this option, the list of
933                                 sockets is reset, and all prior uses of
934                                 this setting will have no
935                                 effect.</para></listitem>
936                         </varlistentry>
937
938                         <varlistentry>
939                                 <term><varname>StartLimitInterval=</varname></term>
940                                 <term><varname>StartLimitBurst=</varname></term>
941
942                                 <listitem><para>Configure service
943                                 start rate limiting. By default,
944                                 services which are started more
945                                 than 5 times within 10 seconds are not
946                                 permitted to start any more times
947                                 until the 10 second interval ends. With
948                                 these two options, this rate limiting
949                                 may be modified. Use
950                                 <varname>StartLimitInterval=</varname>
951                                 to configure the checking interval (defaults to
952                                 <varname>DefaultStartLimitInterval=</varname> in
953                                 manager configuration file, set to 0 to disable
954                                 any kind of rate limiting). Use
955                                 <varname>StartLimitBurst=</varname> to
956                                 configure how many starts per interval
957                                 are allowed (defaults to
958                                 <varname>DefaultStartLimitBurst=</varname> in
959                                 manager configuration file). These
960                                 configuration options are particularly
961                                 useful in conjunction with
962                                 <varname>Restart=</varname>; however,
963                                 they apply to all kinds of starts
964                                 (including manual), not just those
965                                 triggered by the
966                                 <varname>Restart=</varname> logic.
967                                 Note that units which are configured
968                                 for <varname>Restart=</varname> and
969                                 which reach the start limit are not
970                                 attempted to be restarted anymore;
971                                 however, they may still be restarted
972                                 manually at a later point, from which
973                                 point on, the restart logic is again
974                                 activated. Note that
975                                 <command>systemctl
976                                 reset-failed</command> will cause the
977                                 restart rate counter for a service to
978                                 be flushed, which is useful if the
979                                 administrator wants to manually start
980                                 a service and the start limit
981                                 interferes with
982                                 that.</para></listitem>
983                         </varlistentry>
984
985                         <varlistentry>
986                                 <term><varname>StartLimitAction=</varname></term>
987
988                                 <listitem><para>Configure the action
989                                 to take if the rate limit configured
990                                 with
991                                 <varname>StartLimitInterval=</varname>
992                                 and
993                                 <varname>StartLimitBurst=</varname> is
994                                 hit. Takes one of
995                                 <option>none</option>,
996                                 <option>reboot</option>,
997                                 <option>reboot-force</option>, or
998                                 <option>reboot-immediate</option>. If
999                                 <option>none</option> is set,
1000                                 hitting the rate limit will trigger no
1001                                 action besides that the start will not
1002                                 be permitted. <option>reboot</option>
1003                                 causes a reboot following the normal
1004                                 shutdown procedure (i.e. equivalent to
1005                                 <command>systemctl reboot</command>).
1006                                 <option>reboot-force</option> causes
1007                                 a forced reboot which will terminate
1008                                 all processes forcibly but should
1009                                 cause no dirty file systems on reboot
1010                                 (i.e. equivalent to <command>systemctl
1011                                 reboot -f</command>) and
1012                                 <option>reboot-immediate</option>
1013                                 causes immediate execution of the
1014                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1015                                 system call, which might result in
1016                                 data loss. Defaults to
1017                                 <option>none</option>.</para></listitem>
1018                         </varlistentry>
1019
1020                         <varlistentry>
1021                                 <term><varname>RebootArgument=</varname></term>
1022                                 <listitem><para>Configure the optional
1023                                 argument for the
1024                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1025                                 system call if
1026                                 <varname>StartLimitAction=</varname>
1027                                 is a reboot action. This works just
1028                                 like the optional argument to
1029                                 <command>systemctl reboot</command>
1030                                 command.</para></listitem>
1031                         </varlistentry>
1032
1033                         <varlistentry>
1034                                 <term><varname>FailureAction=</varname></term>
1035                                 <listitem><para>Configure the action
1036                                 to take when the service enters a failed
1037                                 state. Takes the same values as
1038                                 <varname>StartLimitAction=</varname>
1039                                 and executes the same actions.
1040                                 Defaults to <option>none</option>.
1041                                 </para></listitem>
1042                         </varlistentry>
1043
1044                 </variablelist>
1045
1046                 <para>Check
1047                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1048                 and
1049                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1050                 for more settings.</para>
1051
1052         </refsect1>
1053
1054         <refsect1>
1055                 <title>Compatibility Options</title>
1056
1057                 <para>The following options are also available in the
1058                 <literal>[Service]</literal> section, but exist purely
1059                 for compatibility reasons and should not be used in
1060                 newly written service files.</para>
1061
1062                 <variablelist class='unit-directives'>
1063                         <varlistentry>
1064                                 <term><varname>SysVStartPriority=</varname></term>
1065                                 <listitem><para>Set the SysV start
1066                                 priority to use to order this service
1067                                 in relation to SysV services lacking
1068                                 LSB headers. This option is only
1069                                 necessary to fix ordering in relation
1070                                 to legacy SysV services that have no
1071                                 ordering information encoded in the
1072                                 script headers. As such, it should only
1073                                 be used as a temporary compatibility
1074                                 option and should not be used in new unit
1075                                 files. Almost always, it is a better
1076                                 choice to add explicit ordering
1077                                 directives via
1078                                 <varname>After=</varname> or
1079                                 <varname>Before=</varname>,
1080                                 instead. For more details, see
1081                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
1082                                 If used, pass an integer value in the
1083                                 range 0-99.</para></listitem>
1084                         </varlistentry>
1085                 </variablelist>
1086         </refsect1>
1087
1088         <refsect1>
1089                   <title>See Also</title>
1090                   <para>
1091                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1092                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1093                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1094                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1095                           <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1096                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1097                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1098                   </para>
1099         </refsect1>
1100
1101 </refentry>