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1<?xml version='1.0'?> <!--*-nxml-*-->
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
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24
25<refentry id="systemd.exec">
26 <refentryinfo>
27 <title>systemd.exec</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.exec</refentrytitle>
42 <manvolnum>5</manvolnum>
43 </refmeta>
44
45 <refnamediv>
46 <refname>systemd.exec</refname>
47 <refpurpose>systemd execution environment configuration</refpurpose>
48 </refnamediv>
49
50 <refsynopsisdiv>
51 <para><filename>systemd.service</filename>,
52 <filename>systemd.socket</filename>,
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53 <filename>systemd.mount</filename>,
54 <filename>systemd.swap</filename></para>
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55 </refsynopsisdiv>
56
57 <refsect1>
58 <title>Description</title>
59
60 <para>Unit configuration files for services, sockets
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61 mount points and swap devices share a subset of
62 configuration options which define the execution
63 environment of spawned processes.</para>
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64
65 <para>This man page lists the configuration options
66 shared by these three unit types. See
67 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
68 for the common options of all unit configuration
69 files, and
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70 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
71 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
72 <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
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73 and
74 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
75 for more information on the specific unit
76 configuration files. The execution specific
77 configuration options are configured in the [Service],
2292707d 78 [Socket], [Mount] resp. [Swap] section, depending on the unit
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79 type.</para>
80 </refsect1>
81
82 <refsect1>
83 <title>Options</title>
84
85 <variablelist>
86
87 <varlistentry>
88 <term><varname>WorkingDirectory=</varname></term>
89
90 <listitem><para>Takes an absolute
91 directory path. Sets the working
92 directory for executed
93 processes.</para></listitem>
94 </varlistentry>
95
96 <varlistentry>
97 <term><varname>RootDirectory=</varname></term>
98
99 <listitem><para>Takes an absolute
100 directory path. Sets the root
101 directory for executed processes, with
102 the
103 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
104 system call. If this is used it must
105 be ensured that the process and all
106 its auxiliary files are available in
107 the <function>chroot()</function>
108 jail.</para></listitem>
109 </varlistentry>
110
111 <varlistentry>
112 <term><varname>User=</varname></term>
113 <term><varname>Group=</varname></term>
114
115 <listitem><para>Sets the Unix user
116 resp. group the processes are executed
117 as. Takes a single user resp. group
118 name or ID as argument. If no group is
119 set the default group of the user is
120 chosen.</para></listitem>
121 </varlistentry>
122
123 <varlistentry>
124 <term><varname>SupplementaryGroups=</varname></term>
125
126 <listitem><para>Sets the supplementary
127 Unix groups the processes are executed
96d4ce01 128 as. This takes a space separated list
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129 of group names or IDs. This option may
130 be specified more than once in which
131 case all listed groups are set as
132 supplementary groups. This option does
f8553ccb 133 not override but extends the list of
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134 supplementary groups configured in the
135 system group database for the
136 user.</para></listitem>
137 </varlistentry>
138
139 <varlistentry>
140 <term><varname>Nice=</varname></term>
141
142 <listitem><para>Sets the default nice
143 level (scheduling priority) for
144 executed processes. Takes an integer
145 between -20 (highest priority) and 19
146 (lowest priority). See
147 <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
148 for details.</para></listitem>
149 </varlistentry>
150
151 <varlistentry>
dd6c17b1 152 <term><varname>OOMScoreAdjust=</varname></term>
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153
154 <listitem><para>Sets the adjustment
155 level for the Out-Of-Memory killer for
156 executed processes. Takes an integer
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157 between -1000 (to disable OOM killing
158 for this process) and 1000 (to make
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159 killing of this process under memory
160 pressure very likely). See <ulink
161 url="http://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
162 for details.</para></listitem>
163 </varlistentry>
164
165 <varlistentry>
166 <term><varname>IOSchedulingClass=</varname></term>
167
168 <listitem><para>Sets the IO scheduling
169 class for executed processes. Takes an
170 integer between 0 and 3 or one of the
171 strings <option>none</option>,
172 <option>realtime</option>,
173 <option>best-effort</option> or
174 <option>idle</option>. See
175 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
176 for details.</para></listitem>
177 </varlistentry>
178
179 <varlistentry>
180 <term><varname>IOSchedulingPriority=</varname></term>
181
182 <listitem><para>Sets the IO scheduling
183 priority for executed processes. Takes
184 an integer between 0 (highest
185 priority) and 7 (lowest priority). The
186 available priorities depend on the
187 selected IO scheduling class (see
188 above). See
189 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
190 for details.</para></listitem>
191 </varlistentry>
192
193 <varlistentry>
194 <term><varname>CPUSchedulingPolicy=</varname></term>
195
196 <listitem><para>Sets the CPU
197 scheduling policy for executed
198 processes. Takes one of
199 <option>other</option>,
200 <option>batch</option>,
201 <option>idle</option>,
202 <option>fifo</option> or
203 <option>rr</option>. See
204 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
205 for details.</para></listitem>
206 </varlistentry>
207
208 <varlistentry>
209 <term><varname>CPUSchedulingPriority=</varname></term>
210
211 <listitem><para>Sets the CPU
212 scheduling priority for executed
213 processes. Takes an integer between 1
214 (lowest priority) and 99 (highest
215 priority). The available priority
216 range depends on the selected CPU
217 scheduling policy (see above). See
218 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
219 for details.</para></listitem>
220 </varlistentry>
221
222 <varlistentry>
223 <term><varname>CPUSchedulingResetOnFork=</varname></term>
224
225 <listitem><para>Takes a boolean
226 argument. If true elevated CPU
227 scheduling priorities and policies
228 will be reset when the executed
229 processes fork, and can hence not leak
230 into child processes. See
231 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
232 for details. Defaults to false.</para></listitem>
233 </varlistentry>
234
235 <varlistentry>
236 <term><varname>CPUAffinity=</varname></term>
237
238 <listitem><para>Controls the CPU
239 affinity of the executed
96d4ce01 240 processes. Takes a space-separated
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241 list of CPU indexes. See
242 <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
243 for details.</para></listitem>
244 </varlistentry>
245
246 <varlistentry>
247 <term><varname>UMask=</varname></term>
248
249 <listitem><para>Controls the file mode
250 creation mask. Takes an access mode in
251 octal notation. See
252 <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
253 for details. Defaults to
254 0002.</para></listitem>
255 </varlistentry>
256
257 <varlistentry>
258 <term><varname>Environment=</varname></term>
259
260 <listitem><para>Sets environment
261 variables for executed
96d4ce01 262 processes. Takes a space-separated
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263 list of variable assignments. This
264 option may be specified more than once
265 in which case all listed variables
266 will be set. If the same variable is
267 set twice the later setting will
268 override the earlier setting. See
269 <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
270 for details.</para></listitem>
271 </varlistentry>
272 <varlistentry>
273 <term><varname>EnvironmentFile=</varname></term>
274 <listitem><para>Similar to
275 <varname>Environment=</varname> but
276 reads the environment variables from a
277 text file. The text file should
96d4ce01 278 contain new-line separated variable
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279 assignments. Empty lines and lines
280 starting with ; or # will be ignored,
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281 which may be used for commenting. The
282 argument passed should be an absolute
283 file name, optionally prefixed with
284 "-", which indicates that if the file
285 does not exist it won't be read and no
286 error or warning message is
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287 logged. The files listed with this
288 directive will be read shortly before
289 the process is executed. Settings from
290 these files override settings made
291 with
292 <varname>Environment=</varname>. If
293 the same variable is set twice from
294 these files the files will be read in
295 the order they are specified and the
296 later setting will override the
297 earlier setting. </para></listitem>
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298 </varlistentry>
299
300 <varlistentry>
301 <term><varname>StandardInput=</varname></term>
302 <listitem><para>Controls where file
303 descriptor 0 (STDIN) of the executed
304 processes is connected to. Takes one
305 of <option>null</option>,
306 <option>tty</option>,
307 <option>tty-force</option>,
308 <option>tty-fail</option> or
309 <option>socket</option>. If
310 <option>null</option> is selected
311 standard input will be connected to
312 <filename>/dev/null</filename>,
313 i.e. all read attempts by the process
314 will result in immediate EOF. If
315 <option>tty</option> is selected
316 standard input is connected to a TTY
317 (as configured by
318 <varname>TTYPath=</varname>, see
319 below) and the executed process
320 becomes the controlling process of the
321 terminal. If the terminal is already
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322 being controlled by another process the
323 executed process waits until the current
324 controlling process releases the
325 terminal.
326 <option>tty-force</option>
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327 is similar to <option>tty</option>,
328 but the executed process is forcefully
329 and immediately made the controlling
330 process of the terminal, potentially
331 removing previous controlling
332 processes from the
333 terminal. <option>tty-fail</option> is
334 similar to <option>tty</option> but if
335 the terminal already has a controlling
336 process start-up of the executed
337 process fails. The
338 <option>socket</option> option is only
339 valid in socket-activated services,
340 and only when the socket configuration
341 file (see
342 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
343 for details) specifies a single socket
344 only. If this option is set standard
345 input will be connected to the socket
346 the service was activated from, which
347 is primarily useful for compatibility
348 with daemons designed for use with the
349 traditional
350 <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
351 daemon. This setting defaults to
352 <option>null</option>.</para></listitem>
353 </varlistentry>
354 <varlistentry>
355 <term><varname>StandardOutput=</varname></term>
356 <listitem><para>Controls where file
357 descriptor 1 (STDOUT) of the executed
358 processes is connected to. Takes one
359 of <option>inherit</option>,
360 <option>null</option>,
361 <option>tty</option>,
362 <option>syslog</option>,
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363 <option>kmsg</option>,
364 <option>kmsg+console</option>,
365 <option>syslog+console</option> or
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366 <option>socket</option>. If set to
367 <option>inherit</option> the file
368 descriptor of standard input is
369 duplicated for standard output. If set
370 to <option>null</option> standard
371 output will be connected to
372 <filename>/dev/null</filename>,
373 i.e. everything written to it will be
374 lost. If set to <option>tty</option>
375 standard output will be connected to a
376 tty (as configured via
377 <varname>TTYPath=</varname>, see
378 below). If the TTY is used for output
379 only the executed process will not
380 become the controlling process of the
381 terminal, and will not fail or wait
382 for other processes to release the
383 terminal. <option>syslog</option>
384 connects standard output to the
385 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
386 system logger. <option>kmsg</option>
387 connects it with the kernel log buffer
388 which is accessible via
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389 <citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>syslog+console</option>
390 and <option>kmsg+console</option> work
391 similarly but copy the output to the
392 system console as
393 well. <option>socket</option> connects
394 standard output to a socket from
395 socket activation, semantics are
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396 similar to the respective option of
397 <varname>StandardInput=</varname>.
398 This setting defaults to
399 <option>inherit</option>.</para></listitem>
400 </varlistentry>
401 <varlistentry>
ad678a06 402 <term><varname>StandardError=</varname></term>
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403 <listitem><para>Controls where file
404 descriptor 2 (STDERR) of the executed
405 processes is connected to. The
406 available options are identical to
407 those of
ad678a06 408 <varname>StandardOutput=</varname>,
5471472d 409 with one exception: if set to
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410 <option>inherit</option> the file
411 descriptor used for standard output is
412 duplicated for standard error. This
413 setting defaults to
414 <option>inherit</option>.</para></listitem>
415 </varlistentry>
416 <varlistentry>
417 <term><varname>TTYPath=</varname></term>
418 <listitem><para>Sets the terminal
419 device node to use if standard input,
420 output or stderr are connected to a
421 TTY (see above). Defaults to
422 <filename>/dev/console</filename>.</para></listitem>
423 </varlistentry>
424 <varlistentry>
48c4fad9 425 <term><varname>SyslogIdentifier=</varname></term>
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426 <listitem><para>Sets the process name
427 to prefix log lines sent to syslog or
428 the kernel log buffer with. If not set
429 defaults to the process name of the
430 executed process. This option is only
431 useful when
432 <varname>StandardOutput=</varname> or
433 <varname>StandardError=</varname> are
434 set to <option>syslog</option> or
435 <option>kmsg</option>.</para></listitem>
436 </varlistentry>
437 <varlistentry>
438 <term><varname>SyslogFacility=</varname></term>
439 <listitem><para>Sets the syslog
440 facility to use when logging to
441 syslog. One of <option>kern</option>,
442 <option>user</option>,
443 <option>mail</option>,
444 <option>daemon</option>,
445 <option>auth</option>,
446 <option>syslog</option>,
447 <option>lpr</option>,
448 <option>news</option>,
449 <option>uucp</option>,
450 <option>cron</option>,
451 <option>authpriv</option>,
452 <option>ftp</option>,
453 <option>local0</option>,
454 <option>local1</option>,
455 <option>local2</option>,
456 <option>local3</option>,
457 <option>local4</option>,
458 <option>local5</option>,
459 <option>local6</option> or
460 <option>local7</option>. See
461 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
462 for details. This option is only
463 useful when
464 <varname>StandardOutput=</varname> or
465 <varname>StandardError=</varname> are
466 set to <option>syslog</option>.
467 Defaults to
468 <option>daemon</option>.</para></listitem>
469 </varlistentry>
470 <varlistentry>
471 <term><varname>SyslogLevel=</varname></term>
472 <listitem><para>Default syslog level
473 to use when logging to syslog or the
474 kernel log buffer. One of
475 <option>emerg</option>,
476 <option>alert</option>,
477 <option>crit</option>,
478 <option>err</option>,
479 <option>warning</option>,
480 <option>notice</option>,
481 <option>info</option>,
482 <option>debug</option>. See
483 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
484 for details. This option is only
485 useful when
486 <varname>StandardOutput=</varname> or
487 <varname>StandardError=</varname> are
488 set to <option>syslog</option> or
489 <option>kmsg</option>. Note that
490 individual lines output by the daemon
491 might be prefixed with a different log
492 level which can be used to override
493 the default log level specified
494 here. The interpretation of these
495 prefixes may be disabled with
74922904 496 <varname>SyslogLevelPrefix=</varname>,
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497 see below. For details see
498 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
499
500 Defaults to
501 <option>info</option>.</para></listitem>
502 </varlistentry>
503
504 <varlistentry>
74922904 505 <term><varname>SyslogLevelPrefix=</varname></term>
dd1eb43b 506 <listitem><para>Takes a boolean
74922904 507 argument. If true and
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508 <varname>StandardOutput=</varname> or
509 <varname>StandardError=</varname> are
510 set to <option>syslog</option> or
511 <option>kmsg</option> log lines
512 written by the executed process that
513 are prefixed with a log level will be
514 passed on to syslog with this log
515 level set but the prefix removed. If
74922904 516 set to false, the interpretation of
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517 these prefixes is disabled and the
518 logged lines are passed on as-is. For
519 details about this prefixing see
520 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
74922904 521 Defaults to true.</para></listitem>
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522 </varlistentry>
523
524 <varlistentry>
03fae018 525 <term><varname>TimerSlackNSec=</varname></term>
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526 <listitem><para>Sets the timer slack
527 in nanoseconds for the executed
f8553ccb 528 processes. The timer slack controls the
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529 accuracy of wake-ups triggered by
530 timers. See
dd1eb43b 531 <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
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532 for more information. Note that in
533 contrast to most other time span
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534 definitions this parameter takes an
535 integer value in nano-seconds and does
536 not understand any other
03fae018 537 units.</para></listitem>
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538 </varlistentry>
539
540 <varlistentry>
541 <term><varname>LimitCPU=</varname></term>
542 <term><varname>LimitFSIZE=</varname></term>
543 <term><varname>LimitDATA=</varname></term>
544 <term><varname>LimitSTACK=</varname></term>
545 <term><varname>LimitCORE=</varname></term>
546 <term><varname>LimitRSS=</varname></term>
547 <term><varname>LimitNOFILE=</varname></term>
548 <term><varname>LimitAS=</varname></term>
549 <term><varname>LimitNPROC=</varname></term>
550 <term><varname>LimitMEMLOCK=</varname></term>
551 <term><varname>LimitLOCKS=</varname></term>
552 <term><varname>LimitSIGPENDING=</varname></term>
553 <term><varname>LimitMSGQUEUE=</varname></term>
554 <term><varname>LimitNICE=</varname></term>
555 <term><varname>LimitRTPRIO=</varname></term>
556 <term><varname>LimitRTTIME=</varname></term>
557 <listitem><para>These settings control
558 various resource limits for executed
559 processes. See
560 <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
561 for details.</para></listitem>
562 </varlistentry>
563
564 <varlistentry>
565 <term><varname>PAMName=</varname></term>
566 <listitem><para>Sets the PAM service
567 name to set up a session as. If set
568 the executed process will be
569 registered as a PAM session under the
570 specified service name. This is only
571 useful in conjunction with the
572 <varname>User=</varname> setting. If
573 not set no PAM session will be opened
574 for the executed processes. See
575 <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
576 for details.</para></listitem>
577 </varlistentry>
578
579 <varlistentry>
580 <term><varname>TCPWrapName=</varname></term>
581 <listitem><para>If this is a
582 socket-activated service this sets the
583 tcpwrap service name to check the
584 permission for the current connection
585 with. This is only useful in
586 conjunction with socket-activated
587 services, and stream sockets (TCP) in
588 particular. It has no effect on other
589 socket types (e.g. datagram/UDP) and on processes
590 unrelated to socket-based
591 activation. If the tcpwrap
592 verification fails daemon start-up
593 will fail and the connection is
594 terminated. See
595 <citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
596 for details.</para></listitem>
597 </varlistentry>
598
599 <varlistentry>
600 <term><varname>Capabilities=</varname></term>
601 <listitem><para>Controls the
602 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
603 set for the executed process. Take a
604 capability string as described in
605 <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
606 Note that this capability set is
607 usually influenced by the capabilities
608 attached to the executed
609 file.</para></listitem>
610 </varlistentry>
611
612 <varlistentry>
613 <term><varname>SecureBits=</varname></term>
614 <listitem><para>Controls the secure
615 bits set for the executed process. See
616 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
617 for details. Takes a list of strings:
618 <option>keep-caps</option>,
619 <option>keep-caps-locked</option>,
620 <option>no-setuid-fixup</option>,
621 <option>no-setuid-fixup-locked</option>,
622 <option>no-setuid-noroot</option> and/or
623 <option>no-setuid-noroot-locked</option>.
624 </para></listitem>
625 </varlistentry>
626
627 <varlistentry>
628 <term><varname>CapabilityBoundingSetDrop=</varname></term>
629
630 <listitem><para>Controls the
631 capability bounding set drop set for
632 the executed process. See
633 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
634 for details. Takes a list of
635 capability names as read by
636 <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
637 </para></listitem>
638 </varlistentry>
639
640 <varlistentry>
641 <term><varname>ControlGroup=</varname></term>
642
643 <listitem><para>Controls the control
644 groups the executed processes shall be
ad678a06 645 made members of. Takes a
96d4ce01 646 space-separated list of cgroup
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647 identifiers. A cgroup identifier has a
648 format like
649 <filename>cpu:/foo/bar</filename>,
650 where "cpu" identifies the kernel
651 control group controller used, and
652 <filename>/foo/bar</filename> is the
653 control group path. The controller name
654 and ":" may be omitted in which case
655 the named systemd control group
656 hierarchy is implied. Alternatively,
657 the path and ":" may be omitted, in
658 which case the default control group
659 path for this unit is implied. This
660 option may be used to place executed
661 processes in arbitrary groups in
662 arbitrary hierachies -- which can be
663 configured externally with additional execution limits. By default
664 systemd will place all executed
96d4ce01 665 processes in separate per-unit control
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666 groups (named after the unit) in the
667 systemd named hierarchy. Since every
668 process can be in one group per
669 hierarchy only overriding the control group
670 path in the named systemd hierarchy
671 will disable automatic placement in
672 the default group. For details about control
673 groups see <ulink
674 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
675 </varlistentry>
676
677 <varlistentry>
678 <term><varname>ReadWriteDirectories=</varname></term>
679 <term><varname>ReadOnlyDirectories=</varname></term>
680 <term><varname>InaccessibleDirectories=</varname></term>
681
682 <listitem><para>Sets up a new
683 file-system name space for executed
684 processes. These options may be used
685 to limit access a process might have
686 to the main file-system
687 hierarchy. Each setting takes a
96d4ce01 688 space-separated list of absolute
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689 directory paths. Directories listed in
690 <varname>ReadWriteDirectories=</varname>
691 are accessible from within the
692 namespace with the same access rights
693 as from outside. Directories listed in
694 <varname>ReadOnlyDirectories=</varname>
695 are accessible for reading only,
696 writing will be refused even if the
697 usual file access controls would
698 permit this. Directories listed in
699 <varname>InaccessibleDirectories=</varname>
700 will be made inaccesible for processes
701 inside the namespace. Note that
702 restricting access with these options
703 does not extend to submounts of a
704 directory. You must list submounts
5471472d 705 separately in these settings to
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706 ensure the same limited access. These
707 options may be specified more than
708 once in which case all directories
709 listed will have limited access from
710 within the
711 namespace.</para></listitem>
712 </varlistentry>
713
714 <varlistentry>
715 <term><varname>PrivateTmp=</varname></term>
716
717 <listitem><para>Takes a boolean
718 argument. If true sets up a new
719 namespace for the executed processes
720 and mounts a private
721 <filename>/tmp</filename> directory
722 inside it, that is not shared by
723 processes outside of the
724 namespace. This is useful to secure
725 access to temporary files of the
726 process, but makes sharing between
727 processes via
728 <filename>/tmp</filename>
729 impossible. Defaults to false.</para></listitem>
730 </varlistentry>
731
732 <varlistentry>
733 <term><varname>MountFlags=</varname></term>
734
735 <listitem><para>Takes a mount
736 propagation flag:
737 <option>shared</option>,
738 <option>slave</option> or
739 <option>private</option>, which
740 control whether namespaces set up with
741 <varname>ReadWriteDirectories=</varname>,
742 <varname>ReadOnlyDirectories=</varname>
743 and
744 <varname>InaccessibleDirectories=</varname>
745 receive or propagate new mounts
746 from/to the main namespace. See
747 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
748 for details. Defaults to
749 <option>shared</option>, i.e. the new
750 namespace will both receive new mount
751 points from the main namespace as well
752 as propagate new mounts to
753 it.</para></listitem>
754 </varlistentry>
755
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756 <varlistentry>
757 <term><varname>UtmpIdentifier=</varname></term>
758
759 <listitem><para>Takes a a four
760 character identifier string for an
761 utmp/wtmp entry for this service. This
762 should only be set for services such
763 as <command>getty</command>
764 implementations where utmp/wtmp
765 entries must be created and cleared
766 before and after execution. If the
767 configured string is longer than four
768 characters it is truncated and the
769 terminal four characters are
770 used. This setting interprets %I style
771 string replacements. This setting is
772 unset by default, i.e. no utmp/wtmp
773 entries are created or cleaned up for
774 this service.</para></listitem>
775 </varlistentry>
776
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777 </variablelist>
778 </refsect1>
779
780 <refsect1>
781 <title>See Also</title>
782 <para>
f3e219a2 783 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
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784 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
785 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
786 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
787 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
2292707d 788 <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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789 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
790 </para>
791 </refsect1>
792
793</refentry>