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nspawn,man: use a common vocabulary when referring to selinux security contexts
[elogind.git] / man / systemd.service.xml
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2 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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9   Copyright 2010 Lennart Poettering
10
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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 starting follow-up units as
176                                 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 starting follow-up units
196                                 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 finished
212                                 starting up. systemd will proceed
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 as well if
301                                 the process takes a name on the D-Bus
302                                 bus.</para>
303                                 </listitem>
304                         </varlistentry>
305
306                         <varlistentry>
307                                 <term><varname>ExecStart=</varname></term>
308                                 <listitem><para>Commands with their
309                                 arguments that are executed when this
310                                 service is started. For each of the
311                                 specified commands, the first argument
312                                 must be an absolute and literal path
313                                 to an executable.</para>
314
315                                 <para>When <varname>Type</varname> is
316                                 not <option>oneshot</option>, only one
317                                 command may be given. When
318                                 <varname>Type=oneshot</varname> is
319                                 used, more than one command may be
320                                 specified. Multiple command lines may
321                                 be concatenated in a single directive,
322                                 by separating them with semicolons
323                                 (these semicolons must be passed as
324                                 separate words). Alternatively, this
325                                 directive may be specified more than
326                                 once with the same effect.
327                                 Lone semicolons may be escaped as
328                                 <literal>\;</literal>. If the empty
329                                 string is assigned to this option, the
330                                 list of commands to start is reset,
331                                 prior assignments of this option will
332                                 have no effect.</para>
333
334                                 <para>Each command line is split on
335                                 whitespace, with the first item being
336                                 the command to execute, and the
337                                 subsequent items being the arguments.
338                                 Double quotes ("...") and single
339                                 quotes ('...') may be used, in which
340                                 case everything until the next
341                                 matching quote becomes part of the
342                                 same argument. Quotes themselves are
343                                 removed after parsing. In addition, a
344                                 trailing backslash
345                                 (<literal>\</literal>) may be used to
346                                 merge lines. This syntax is intended
347                                 to be very similar to shell syntax,
348                                 but only the meta-characters and
349                                 expansions described in the following
350                                 paragraphs are understood.
351                                 Specifically, redirection using
352                                 <literal>&lt;</literal>,
353                                 <literal>&lt;&lt;</literal>,
354                                 <literal>&gt;</literal>, and
355                                 <literal>&gt;&gt;</literal>, pipes
356                                 using <literal>|</literal>, and
357                                 running programs in the background
358                                 using <literal>&amp;</literal>
359                                 and <emphasis>other elements of shell
360                                 syntax are not supported</emphasis>.
361                                 </para>
362
363                                 <para>If more than one command is
364                                 specified, the commands are invoked
365                                 one by one sequentially in the order
366                                 they appear in the unit file. If one
367                                 of the commands fails (and is not
368                                 prefixed with <literal>-</literal>),
369                                 other lines are not executed and the
370                                 unit is considered failed.</para>
371
372                                 <para>Unless
373                                 <varname>Type=forking</varname> is
374                                 set, the process started via this
375                                 command line will be considered the
376                                 main process of the daemon.</para>
377
378                                 <para>The command line accepts
379                                 <literal>%</literal> specifiers as
380                                 described in
381                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
382                                 Note that the first argument of the
383                                 command line (i.e. the program to
384                                 execute) may not include
385                                 specifiers.</para>
386
387                                 <para>Basic environment variable
388                                 substitution is supported. Use
389                                 <literal>${FOO}</literal> as part of a
390                                 word, or as a word of its own on the
391                                 command line, in which case it will be
392                                 replaced by the value of the
393                                 environment variable including all
394                                 whitespace it contains, resulting in a
395                                 single argument. Use
396                                 <literal>$FOO</literal> as a separate
397                                 word on the command line, in which
398                                 case it will be replaced by the value
399                                 of the environment variable split at
400                                 whitespace, resulting in zero or more
401                                 arguments. To pass a literal dollar
402                                 sign, use <literal>$$</literal>.
403                                 Variables whose value is not known at
404                                 expansion time are treated as empty
405                                 strings. Note that the first argument
406                                 (i.e. the program to execute) may not
407                                 be a variable.</para>
408
409                                 <para>Variables to be used in this
410                                 fashion may be defined through
411                                 <varname>Environment=</varname> and
412                                 <varname>EnvironmentFile=</varname>.
413                                 In addition, variables listed in
414                                 section "Environment variables in
415                                 spawned processes" in
416                                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
417                                 which are considered "static
418                                 configuration" may used (this includes
419                                 e.g. <varname>$USER</varname>, but not
420                                 <varname>$TERM</varname>).</para>
421
422                                 <para>Optionally, if the absolute file
423                                 name is prefixed with
424                                 <literal>@</literal>, the second token
425                                 will be passed as
426                                 <literal>argv[0]</literal> to the
427                                 executed process, followed by the
428                                 further arguments specified. If the
429                                 absolute filename is prefixed with
430                                 <literal>-</literal>, an exit code of
431                                 the command normally considered a
432                                 failure (i.e. non-zero exit status or
433                                 abnormal exit due to signal) is ignored
434                                 and considered success. If both
435                                 <literal>-</literal> and
436                                 <literal>@</literal> are used, they
437                                 can appear in either order.</para>
438
439                                 <para>Note that this setting does not
440                                 directly support shell command
441                                 lines. If shell command lines are to
442                                 be used, they need to be passed
443                                 explicitly to a shell implementation
444                                 of some kind. Example:</para>
445                                 <programlisting>ExecStart=/bin/sh -c 'dmesg | tac'
446                                 </programlisting>
447
448                                 <para>Example:</para>
449                                 <programlisting>ExecStart=/bin/echo one ; /bin/echo "two two"
450                                 </programlisting>
451                                 <para>This will execute
452                                 <command>/bin/echo</command> two
453                                 times, each time with one argument,
454                                 <literal>one</literal> and
455                                 <literal>two two</literal>,
456                                 respectively. Since two commands are
457                                 specified,
458                                 <varname>Type=oneshot</varname> must
459                                 be used.</para>
460
461                                 <para>Example:</para>
462                                 <programlisting>ExecStart=/bin/echo / &gt;/dev/null &amp; \; \
463 /bin/ls
464                                 </programlisting>
465                                 <para>This will execute
466                                 <command>/bin/echo</command> with five
467                                 arguments: <literal>/</literal>,
468                                 <literal>&gt;/dev/null</literal>,
469                                 <literal>&amp;</literal>,
470                                 <literal>;</literal>, and
471                                 <literal>/bin/ls</literal>.</para>
472
473                                 <para>Example:</para>
474                                 <programlisting>Environment="ONE=one" 'TWO=two two'
475 ExecStart=/bin/echo $ONE $TWO ${TWO}
476                                 </programlisting>
477                                 <para>This will execute
478                                 <command>/bin/echo</command> with four
479                                 arguments: <literal>one</literal>,
480                                 <literal>two</literal>,
481                                 <literal>two</literal>, and
482                                 <literal>two two</literal>.</para>
483                               </listitem>
484                         </varlistentry>
485
486                         <varlistentry>
487                                 <term><varname>ExecStartPre=</varname></term>
488                                 <term><varname>ExecStartPost=</varname></term>
489                                 <listitem><para>Additional commands
490                                 that are executed before or after
491                                 the command in
492                                 <varname>ExecStart=</varname>, respectively.
493                                 Syntax is the same as for
494                                 <varname>ExecStart=</varname>, except
495                                 that multiple command lines are allowed
496                                 and the commands are executed one
497                                 after the other, serially.</para>
498
499                                 <para>If any of those commands (not
500                                 prefixed with <literal>-</literal>)
501                                 fail, the rest are not executed and
502                                 the unit is considered failed.</para>
503                                 </listitem>
504                         </varlistentry>
505
506                         <varlistentry>
507                                 <term><varname>ExecReload=</varname></term>
508                                 <listitem><para>Commands to execute to
509                                 trigger a configuration reload in the
510                                 service. This argument takes multiple
511                                 command lines, following the same
512                                 scheme as described for
513                                 <varname>ExecStart=</varname>
514                                 above. Use of this setting is
515                                 optional. Specifier and environment
516                                 variable substitution is supported
517                                 here following the same scheme as for
518                                 <varname>ExecStart=</varname>.</para>
519
520                                 <para>One additional special
521                                 environment variables is set: if known
522                                 <varname>$MAINPID</varname> is set to
523                                 the main process of the daemon, and
524                                 may be used for command lines like the
525                                 following:</para>
526
527                                 <programlisting>/bin/kill -HUP $MAINPID</programlisting>
528                                 </listitem>
529                         </varlistentry>
530
531                         <varlistentry>
532                                 <term><varname>ExecStop=</varname></term>
533                                 <listitem><para>Commands to execute to
534                                 stop the service started via
535                                 <varname>ExecStart=</varname>. This
536                                 argument takes multiple command lines,
537                                 following the same scheme as described
538                                 for <varname>ExecStart=</varname>
539                                 above. Use of this setting is
540                                 optional. All processes remaining for
541                                 a service after the commands
542                                 configured in this option are run are
543                                 terminated according to the
544                                 <varname>KillMode=</varname> setting
545                                 (see
546                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>). If
547                                 this option is not specified, the
548                                 process is terminated right-away when
549                                 service stop is requested. Specifier
550                                 and environment variable substitution
551                                 is supported (including
552                                 <varname>$MAINPID</varname>, see
553                                 above).</para></listitem>
554                         </varlistentry>
555
556                         <varlistentry>
557                                 <term><varname>ExecStopPost=</varname></term>
558                                 <listitem><para>Additional commands
559                                 that are executed after the service
560                                 was stopped. This includes cases where
561                                 the commands configured in
562                                 <varname>ExecStop=</varname> were used,
563                                 where the service does not have any
564                                 <varname>ExecStop=</varname> defined, or
565                                 where the service exited unexpectedly. This
566                                 argument takes multiple command lines,
567                                 following the same scheme as described
568                                 for <varname>ExecStart</varname>. Use
569                                 of these settings is
570                                 optional. Specifier and environment
571                                 variable substitution is
572                                 supported.</para></listitem>
573                         </varlistentry>
574
575                         <varlistentry>
576                                 <term><varname>RestartSec=</varname></term>
577                                 <listitem><para>Configures the time to
578                                 sleep before restarting a service (as
579                                 configured with
580                                 <varname>Restart=</varname>). Takes a
581                                 unit-less value in seconds, or a time
582                                 span value such as "5min
583                                 20s". Defaults to
584                                 100ms.</para></listitem>
585                         </varlistentry>
586
587                         <varlistentry>
588                                 <term><varname>TimeoutStartSec=</varname></term>
589                                 <listitem><para>Configures the time to
590                                 wait for start-up. If a
591                                 daemon service does not signal
592                                 start-up completion within the
593                                 configured time, the service will be
594                                 considered failed and be shut down
595                                 again.
596                                 Takes a unit-less value in seconds, or a
597                                 time span value such as "5min
598                                 20s". Pass 0 to disable the timeout
599                                 logic. Defaults to <varname>TimeoutStartSec=</varname> from the
600                                 manager configuration file, except when
601                                 <varname>Type=oneshot</varname> is
602                                 used, in which case the timeout
603                                 is disabled by default.
604                                 </para></listitem>
605                         </varlistentry>
606
607                         <varlistentry>
608                                 <term><varname>TimeoutStopSec=</varname></term>
609                                 <listitem><para>Configures the time to
610                                 wait for stop. If a service is asked
611                                 to stop but does not terminate in the
612                                 specified time, it will be terminated
613                                 forcibly via <constant>SIGTERM</constant>, and after
614                                 another delay of this time with
615                                 <constant>SIGKILL</constant> (See
616                                 <varname>KillMode=</varname>
617                                 in <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
618                                 Takes a unit-less value in seconds, or a
619                                 time span value such as "5min
620                                 20s". Pass 0 to disable the timeout
621                                 logic. Defaults to <varname>TimeoutStartSec=</varname> from the
622                                 manager configuration file.
623                                 </para></listitem>
624                         </varlistentry>
625
626                         <varlistentry>
627                                 <term><varname>TimeoutSec=</varname></term>
628                                 <listitem><para>A shorthand for configuring
629                                 both <varname>TimeoutStartSec=</varname>
630                                 and <varname>TimeoutStopSec=</varname>
631                                 to the specified value.
632                                 </para></listitem>
633                         </varlistentry>
634
635                         <varlistentry>
636                                 <term><varname>WatchdogSec=</varname></term>
637                                 <listitem><para>Configures the
638                                 watchdog timeout for a service. The
639                                 watchdog is activated when the start-up is
640                                 completed. The service must call
641                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
642                                 regularly with "WATCHDOG=1" (i.e. the
643                                 "keep-alive ping"). If the time
644                                 between two such calls is larger than
645                                 the configured time, then the service
646                                 is placed in a failure state. By
647                                 setting <varname>Restart=</varname> to
648                                 <option>on-failure</option> or
649                                 <option>always</option>, the service
650                                 will be automatically restarted. The
651                                 time configured here will be passed to
652                                 the executed service process in the
653                                 <varname>WATCHDOG_USEC=</varname>
654                                 environment variable. This allows
655                                 daemons to automatically enable the
656                                 keep-alive pinging logic if watchdog
657                                 support is enabled for the service. If
658                                 this option is used,
659                                 <varname>NotifyAccess=</varname> (see
660                                 below) should be set to open access to
661                                 the notification socket provided by
662                                 systemd. If
663                                 <varname>NotifyAccess=</varname> is
664                                 not set, it will be implicitly set to
665                                 <option>main</option>. Defaults to 0,
666                                 which disables this
667                                 feature.</para></listitem>
668                         </varlistentry>
669
670                         <varlistentry>
671                                 <term><varname>Restart=</varname></term>
672                                 <listitem><para>Configures whether the
673                                 service shall be restarted when the
674                                 service process exits, is killed,
675                                 or a timeout is reached. The service
676                                 process may be the main service
677                                 process, but also one of the processes
678                                 specified with
679                                 <varname>ExecStartPre=</varname>,
680                                 <varname>ExecStartPost=</varname>,
681                                 <varname>ExecStopPre=</varname>,
682                                 <varname>ExecStopPost=</varname>, or
683                                 <varname>ExecReload=</varname>.
684                                 When the death of the process is a
685                                 result of systemd operation (e.g. service
686                                 stop or restart), the service will not be
687                                 restarted. Timeouts include missing
688                                 the watchdog "keep-alive ping"
689                                 deadline and a service start, reload,
690                                 and stop operation timeouts.</para>
691
692                                 <para>Takes one of
693                                 <option>no</option>,
694                                 <option>on-success</option>,
695                                 <option>on-failure</option>,
696                                 <option>on-watchdog</option>,
697                                 <option>on-abort</option>, or
698                                 <option>always</option>. If set to
699                                 <option>no</option> (the default), the
700                                 service will not be restarted. If set to
701                                 <option>on-success</option>, it will be
702                                 restarted only when the service process
703                                 exits cleanly.
704                                 In this context, a clean exit means
705                                 an exit code of 0, or one of the signals
706                                 <constant>SIGHUP</constant>, <constant>SIGINT</constant>, <constant>SIGTERM</constant>, or <constant>SIGPIPE</constant>, and
707                                 additionally, exit statuses and signals
708                                 specified in <varname>SuccessExitStatus=</varname>.
709                                 If set to <option>on-failure</option>,
710                                 the service will be restarted when the
711                                 process exits with an nonzero exit code,
712                                 is terminated by a signal (including on
713                                 core dump), when an operation (such as
714                                 service reload) times out, and when the
715                                 configured watchdog timeout is triggered.
716                                 If set to
717                                 <option>on-abort</option>, the service
718                                 will be restarted only if the service
719                                 process exits due to an uncaught
720                                 signal not specified as a clean exit
721                                 status.
722                                 If set to
723                                 <option>on-watchdog</option>, the service
724                                 will be restarted only if the watchdog
725                                 timeout for the service expires.
726                                 If set to
727                                 <option>always</option>, the service
728                                 will be restarted regardless of whether
729                                 it exited cleanly or not, got
730                                 terminated abnormally by a signal or
731                                 hit a timeout.</para>
732
733                                 <para>In addition to the above settings,
734                                 the service will not be restarted if the
735                                 exit code or signal is specified in
736                                 <varname>RestartPreventExitStatus=</varname>
737                                 (see below).</para></listitem>
738                         </varlistentry>
739
740                         <varlistentry>
741                                 <term><varname>SuccessExitStatus=</varname></term>
742                                 <listitem><para>Takes a list of exit
743                                 status definitions that when returned
744                                 by the main service process will be
745                                 considered successful termination, in
746                                 addition to the normal successful exit
747                                 code 0 and the signals <constant>SIGHUP</constant>, <constant>SIGINT</constant>,
748                                 <constant>SIGTERM</constant>, and <constant>SIGPIPE</constant>. Exit status
749                                 definitions can either be numeric exit
750                                 codes or termination signal names,
751                                 separated by spaces. For example:
752                                 <programlisting>SuccessExitStatus=1 2 8 <constant>SIGKILL</constant></programlisting>
753                                 ensures that exit codes 1, 2, 8 and
754                                 the termination signal
755                                 <constant>SIGKILL</constant> are
756                                 considered clean service terminations.
757                                 </para>
758
759                                 <para>Note that if a process has a
760                                 signal handler installed and exits by
761                                 calling
762                                 <citerefentry><refentrytitle>_exit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
763                                 in response to a signal, the
764                                 information about the signal is lost.
765                                 Programs should instead perform cleanup and kill themselves with the same signal instead. See
766                                 <ulink url="http://www.cons.org/cracauer/sigint.html">Proper handling of SIGINT/SIGQUIT — How to be a proper program</ulink>.</para>
767
768                                 <para>This option may appear more than once
769                                 in which case the list of successful
770                                 exit statuses is merged. If the empty
771                                 string is assigned to this option, the
772                                 list is reset, all prior assignments
773                                 of this option will have no
774                                 effect.</para></listitem>
775                         </varlistentry>
776
777                         <varlistentry>
778                                 <term><varname>RestartPreventExitStatus=</varname></term>
779                                 <listitem><para>Takes a list of exit
780                                 status definitions that when returned
781                                 by the main service process will
782                                 prevent automatic service restarts
783                                 regardless of the restart setting
784                                 configured with
785                                 <varname>Restart=</varname>. Exit
786                                 status definitions can either be
787                                 numeric exit codes or termination
788                                 signal names, and are separated by
789                                 spaces. Defaults to the empty list, so
790                                 that by default no exit status is
791                                 excluded from the configured restart
792                                 logic. Example:
793                                 <literal>RestartPreventExitStatus=1 6
794                                 SIGABRT</literal>, ensures that exit
795                                 codes 1 and 6 and the termination
796                                 signal SIGABRT will not result in
797                                 automatic service 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, 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
811                                 related 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>,
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>,
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 O_NONBLOCK flag
857                                 for all file descriptors passed via
858                                 socket-based activation. If true, all
859                                 file descriptors >= 3 (i.e. all except
860                                 STDIN/STDOUT/STDERR) will have
861                                 the O_NONBLOCK flag set and hence are in
862                                 non-blocking mode. This option is only
863                                 useful in conjunction with a socket
864                                 unit, as described in
865                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Defaults
866                                 to false.</para></listitem>
867                         </varlistentry>
868
869                         <varlistentry>
870                                 <term><varname>NotifyAccess=</varname></term>
871                                 <listitem><para>Controls access to the
872                                 service status notification socket, as
873                                 accessible via the
874                                 <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>
875                                 call. Takes one of
876                                 <option>none</option> (the default),
877                                 <option>main</option> or
878                                 <option>all</option>. If
879                                 <option>none</option>, no daemon status
880                                 updates are accepted from the service
881                                 processes, all status update messages
882                                 are ignored. If <option>main</option>,
883                                 only service updates sent from the
884                                 main process of the service are
885                                 accepted. If <option>all</option>, all
886                                 services updates from all members of
887                                 the service's control group are
888                                 accepted. This option should be set to
889                                 open access to the notification socket
890                                 when using
891                                 <varname>Type=notify</varname> or
892                                 <varname>WatchdogSec=</varname> (see
893                                 above). If those options are used but
894                                 <varname>NotifyAccess=</varname> is not
895                                 configured, it will be implicitly set
896                                 to
897                                 <option>main</option>.</para></listitem>
898                         </varlistentry>
899
900                         <varlistentry>
901                                 <term><varname>Sockets=</varname></term>
902                                 <listitem><para>Specifies the name of
903                                 the socket units this service shall
904                                 inherit the sockets from when the
905                                 service is started. Normally it
906                                 should not be necessary to use this
907                                 setting as all sockets whose unit
908                                 shares the same name as the service
909                                 (ignoring the different suffix of course)
910                                 are passed to the spawned
911                                 process.</para>
912
913                                 <para>Note that the same socket may be
914                                 passed to multiple processes at the
915                                 same time. Also note that a different
916                                 service may be activated on incoming
917                                 traffic than inherits the sockets. Or
918                                 in other words: the
919                                 <varname>Service=</varname> setting of
920                                 <filename>.socket</filename> units
921                                 does not have to match the inverse of
922                                 the <varname>Sockets=</varname>
923                                 setting of the
924                                 <filename>.service</filename> it
925                                 refers to.</para>
926
927                                 <para>This option may appear more than
928                                 once, in which case the list of socket
929                                 units is merged. If the empty string
930                                 is assigned to this option, the list of
931                                 sockets is reset, all prior uses of
932                                 this setting will have no
933                                 effect.</para></listitem>
934                         </varlistentry>
935
936                         <varlistentry>
937                                 <term><varname>StartLimitInterval=</varname></term>
938                                 <term><varname>StartLimitBurst=</varname></term>
939
940                                 <listitem><para>Configure service
941                                 start rate limiting. By default,
942                                 services which are started more often
943                                 than 5 times within 10s are not
944                                 permitted to start any more times
945                                 until the 10s interval ends. With
946                                 these two options, this rate limiting
947                                 may be modified. Use
948                                 <varname>StartLimitInterval=</varname>
949                                 to configure the checking interval (defaults to
950                                 <varname>DefaultStartLimitInterval=</varname> in
951                                 manager configuration file, set to 0 to disable
952                                 any kind of rate limiting). Use
953                                 <varname>StartLimitBurst=</varname> to
954                                 configure how many starts per interval
955                                 are allowed (defaults to
956                                 <varname>DefaultStartLimitBurst=</varname> in
957                                 manager configuration file). These
958                                 configuration options are particularly
959                                 useful in conjunction with
960                                 <varname>Restart=</varname>, however
961                                 apply to all kinds of starts
962                                 (including manual), not just those
963                                 triggered by the
964                                 <varname>Restart=</varname> logic.
965                                 Note that units which are configured
966                                 for <varname>Restart=</varname> and
967                                 which reach the start limit are not
968                                 attempted to be restarted anymore,
969                                 however they may still be restarted
970                                 manually at a later point from which
971                                 point on the restart logic is again
972                                 activated. Note that
973                                 <command>systemctl
974                                 reset-failed</command> will cause the
975                                 restart rate counter for a service to
976                                 be flushed, which is useful if the
977                                 administrator wants to manually start
978                                 a service and the start limit
979                                 interferes with
980                                 that.</para></listitem>
981                         </varlistentry>
982
983                         <varlistentry>
984                                 <term><varname>StartLimitAction=</varname></term>
985
986                                 <listitem><para>Configure the action
987                                 to take if the rate limit configured
988                                 with
989                                 <varname>StartLimitInterval=</varname>
990                                 and
991                                 <varname>StartLimitBurst=</varname> is
992                                 hit. Takes one of
993                                 <option>none</option>,
994                                 <option>reboot</option>,
995                                 <option>reboot-force</option> or
996                                 <option>reboot-immediate</option>. If
997                                 <option>none</option> is set,
998                                 hitting the rate limit will trigger no
999                                 action besides that the start will not
1000                                 be
1001                                 permitted. <option>reboot</option>
1002                                 causes a reboot following the normal
1003                                 shutdown procedure (i.e. equivalent to
1004                                 <command>systemctl reboot</command>),
1005                                 <option>reboot-force</option> causes
1006                                 an forced reboot which will terminate
1007                                 all processes forcibly but should
1008                                 cause no dirty file systems on reboot
1009                                 (i.e. equivalent to <command>systemctl
1010                                 reboot -f</command>) and
1011                                 <option>reboot-immediate</option>
1012                                 causes immediate execution of the
1013                                 <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
1014                                 system call, which might result in
1015                                 data loss.  Defaults to
1016                                 <option>none</option>.</para></listitem>
1017                         </varlistentry>
1018
1019                 </variablelist>
1020
1021                 <para>Check
1022                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1023                 and
1024                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1025                 for more settings.</para>
1026
1027         </refsect1>
1028
1029         <refsect1>
1030                 <title>Compatibility Options</title>
1031
1032                 <para>The following options are also available in the
1033                 <literal>[Service]</literal> section, but exist purely
1034                 for compatibility reasons and should not be used in
1035                 newly written service files.</para>
1036
1037                 <variablelist class='unit-directives'>
1038                         <varlistentry>
1039                                 <term><varname>SysVStartPriority=</varname></term>
1040                                 <listitem><para>Set the SysV start
1041                                 priority to use to order this service
1042                                 in relation to SysV services lacking
1043                                 LSB headers. This option is only
1044                                 necessary to fix ordering in relation
1045                                 to legacy SysV services, that have no
1046                                 ordering information encoded in the
1047                                 script headers. As such it should only
1048                                 be used as temporary compatibility
1049                                 option, and not be used in new unit
1050                                 files. Almost always it is a better
1051                                 choice to add explicit ordering
1052                                 directives via
1053                                 <varname>After=</varname> or
1054                                 <varname>Before=</varname>,
1055                                 instead. For more details see
1056                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If
1057                                 used, pass an integer value in the
1058                                 range 0-99.</para></listitem>
1059                         </varlistentry>
1060
1061                 </variablelist>
1062         </refsect1>
1063
1064         <refsect1>
1065                   <title>See Also</title>
1066                   <para>
1067                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1068                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1069                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1070                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1071                           <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1072                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1073                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
1074                   </para>
1075         </refsect1>
1076
1077 </refentry>