1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
|
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>systemd.exec</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
a.headerlink {
color: #c60f0f;
font-size: 0.8em;
padding: 0 4px 0 4px;
text-decoration: none;
visibility: hidden;
}
a.headerlink:hover {
background-color: #c60f0f;
color: white;
}
h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
visibility: visible;
}
</style><a href="index.html">Index </a>·
<a href="systemd.directives.html">Directives </a>·
<a href="../python-systemd/index.html">Python </a>·
<a href="../libudev/index.html">libudev </a>·
<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 215</span><hr><div class="refentry"><a name="systemd.exec"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd.exec — Execution environment configuration</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename"><em class="replaceable"><code>service</code></em>.service</code>,
<code class="filename"><em class="replaceable"><code>socket</code></em>.socket</code>,
<code class="filename"><em class="replaceable"><code>mount</code></em>.mount</code>,
<code class="filename"><em class="replaceable"><code>swap</code></em>.swap</code></p></div><div class="refsect1"><a name="idm214176829472"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>Unit configuration files for services, sockets,
mount points, and swap devices share a subset of
configuration options which define the execution
environment of spawned processes.</p><p>This man page lists the configuration options
shared by these four unit types. See
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>
for the common options of all unit configuration
files, and
<a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>,
<a href="systemd.swap.html"><span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span></a>,
and
<a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a>
for more information on the specific unit
configuration files. The execution specific
configuration options are configured in the [Service],
[Socket], [Mount], or [Swap] sections, depending on the unit
type.</p></div><div class="refsect1"><a name="idm214178282400"></a><h2 id="Options">Options<a class="headerlink" title="Permalink to this headline" href="#Options">¶</a></h2><div class="variablelist"><dl class="variablelist"><dt id="WorkingDirectory="><span class="term"><code class="varname">WorkingDirectory=</code></span><a class="headerlink" title="Permalink to this term" href="#WorkingDirectory=">¶</a></dt><dd><p>Takes an absolute
directory path. Sets the working
directory for executed processes. If
not set, defaults to the root directory
when systemd is running as a system
instance and the respective user's
home directory if run as
user.</p></dd><dt id="RootDirectory="><span class="term"><code class="varname">RootDirectory=</code></span><a class="headerlink" title="Permalink to this term" href="#RootDirectory=">¶</a></dt><dd><p>Takes an absolute
directory path. Sets the root
directory for executed processes, with
the
<a href="chroot.html"><span class="citerefentry"><span class="refentrytitle">chroot</span>(2)</span></a>
system call. If this is used, it must
be ensured that the process and all
its auxiliary files are available in
the <code class="function">chroot()</code>
jail.</p></dd><dt id="User="><span class="term"><code class="varname">User=</code>, </span><span class="term"><code class="varname">Group=</code></span><a class="headerlink" title="Permalink to this term" href="#User=">¶</a></dt><dd><p>Sets the Unix user
or group that the processes are executed
as, respectively. Takes a single user or group
name or ID as argument. If no group is
set, the default group of the user is
chosen.</p></dd><dt id="SupplementaryGroups="><span class="term"><code class="varname">SupplementaryGroups=</code></span><a class="headerlink" title="Permalink to this term" href="#SupplementaryGroups=">¶</a></dt><dd><p>Sets the supplementary
Unix groups the processes are executed
as. This takes a space-separated list
of group names or IDs. This option may
be specified more than once in which
case all listed groups are set as
supplementary groups. When the empty
string is assigned the list of
supplementary groups is reset, and all
assignments prior to this one will
have no effect. In any way, this
option does not override, but extends
the list of supplementary groups
configured in the system group
database for the
user.</p></dd><dt id="Nice="><span class="term"><code class="varname">Nice=</code></span><a class="headerlink" title="Permalink to this term" href="#Nice=">¶</a></dt><dd><p>Sets the default nice
level (scheduling priority) for
executed processes. Takes an integer
between -20 (highest priority) and 19
(lowest priority). See
<a href="setpriority.html"><span class="citerefentry"><span class="refentrytitle">setpriority</span>(2)</span></a>
for details.</p></dd><dt id="OOMScoreAdjust="><span class="term"><code class="varname">OOMScoreAdjust=</code></span><a class="headerlink" title="Permalink to this term" href="#OOMScoreAdjust=">¶</a></dt><dd><p>Sets the adjustment
level for the Out-Of-Memory killer for
executed processes. Takes an integer
between -1000 (to disable OOM killing
for this process) and 1000 (to make
killing of this process under memory
pressure very likely). See <a class="ulink" href="https://www.kernel.org/doc/Documentation/filesystems/proc.txt" target="_top">proc.txt</a>
for details.</p></dd><dt id="IOSchedulingClass="><span class="term"><code class="varname">IOSchedulingClass=</code></span><a class="headerlink" title="Permalink to this term" href="#IOSchedulingClass=">¶</a></dt><dd><p>Sets the IO scheduling
class for executed processes. Takes an
integer between 0 and 3 or one of the
strings <code class="option">none</code>,
<code class="option">realtime</code>,
<code class="option">best-effort</code> or
<code class="option">idle</code>. See
<a href="ioprio_set.html"><span class="citerefentry"><span class="refentrytitle">ioprio_set</span>(2)</span></a>
for details.</p></dd><dt id="IOSchedulingPriority="><span class="term"><code class="varname">IOSchedulingPriority=</code></span><a class="headerlink" title="Permalink to this term" href="#IOSchedulingPriority=">¶</a></dt><dd><p>Sets the IO scheduling
priority for executed processes. Takes
an integer between 0 (highest
priority) and 7 (lowest priority). The
available priorities depend on the
selected IO scheduling class (see
above). See
<a href="ioprio_set.html"><span class="citerefentry"><span class="refentrytitle">ioprio_set</span>(2)</span></a>
for details.</p></dd><dt id="CPUSchedulingPolicy="><span class="term"><code class="varname">CPUSchedulingPolicy=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUSchedulingPolicy=">¶</a></dt><dd><p>Sets the CPU
scheduling policy for executed
processes. Takes one of
<code class="option">other</code>,
<code class="option">batch</code>,
<code class="option">idle</code>,
<code class="option">fifo</code> or
<code class="option">rr</code>. See
<a href="sched_setscheduler.html"><span class="citerefentry"><span class="refentrytitle">sched_setscheduler</span>(2)</span></a>
for details.</p></dd><dt id="CPUSchedulingPriority="><span class="term"><code class="varname">CPUSchedulingPriority=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUSchedulingPriority=">¶</a></dt><dd><p>Sets the CPU
scheduling priority for executed
processes. The available priority
range depends on the selected CPU
scheduling policy (see above). For
real-time scheduling policies an
integer between 1 (lowest priority)
and 99 (highest priority) can be used.
See <a href="sched_setscheduler.html"><span class="citerefentry"><span class="refentrytitle">sched_setscheduler</span>(2)</span></a>
for details.
</p></dd><dt id="CPUSchedulingResetOnFork="><span class="term"><code class="varname">CPUSchedulingResetOnFork=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUSchedulingResetOnFork=">¶</a></dt><dd><p>Takes a boolean
argument. If true, elevated CPU
scheduling priorities and policies
will be reset when the executed
processes fork, and can hence not leak
into child processes. See
<a href="sched_setscheduler.html"><span class="citerefentry"><span class="refentrytitle">sched_setscheduler</span>(2)</span></a>
for details. Defaults to false.</p></dd><dt id="CPUAffinity="><span class="term"><code class="varname">CPUAffinity=</code></span><a class="headerlink" title="Permalink to this term" href="#CPUAffinity=">¶</a></dt><dd><p>Controls the CPU
affinity of the executed
processes. Takes a space-separated
list of CPU indices. This option may
be specified more than once in which
case the specificed CPU affinity masks
are merged. If the empty string is
assigned, the mask is reset, all
assignments prior to this will have no
effect. See
<a href="sched_setaffinity.html"><span class="citerefentry"><span class="refentrytitle">sched_setaffinity</span>(2)</span></a>
for details.</p></dd><dt id="UMask="><span class="term"><code class="varname">UMask=</code></span><a class="headerlink" title="Permalink to this term" href="#UMask=">¶</a></dt><dd><p>Controls the file mode
creation mask. Takes an access mode in
octal notation. See
<a href="umask.html"><span class="citerefentry"><span class="refentrytitle">umask</span>(2)</span></a>
for details. Defaults to
0022.</p></dd><dt id="Environment="><span class="term"><code class="varname">Environment=</code></span><a class="headerlink" title="Permalink to this term" href="#Environment=">¶</a></dt><dd><p>Sets environment
variables for executed
processes. Takes a space-separated
list of variable assignments. This
option may be specified more than once
in which case all listed variables
will be set. If the same variable is
set twice, the later setting will
override the earlier setting. If the
empty string is assigned to this
option, the list of environment
variables is reset, all prior
assignments have no effect.
Variable expansion is not performed
inside the strings, however, specifier
expansion is possible. The $ character has
no special meaning.
If you need to assign a value containing spaces
to a variable, use double quotes (")
for the assignment.</p><p>Example:
</p><pre class="programlisting">Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"</pre><p>
gives three variables "<code class="literal">VAR1</code>",
"<code class="literal">VAR2</code>", "<code class="literal">VAR3</code>"
with the values "<code class="literal">word1 word2</code>",
"<code class="literal">word3</code>", "<code class="literal">$word 5 6</code>".
</p><p>
See
<a href="environ.html"><span class="citerefentry"><span class="refentrytitle">environ</span>(7)</span></a>
for details about environment variables.</p></dd><dt id="EnvironmentFile="><span class="term"><code class="varname">EnvironmentFile=</code></span><a class="headerlink" title="Permalink to this term" href="#EnvironmentFile=">¶</a></dt><dd><p>Similar to
<code class="varname">Environment=</code> but
reads the environment variables from a
text file. The text file should
contain new-line-separated variable
assignments. Empty lines and lines
starting with ; or # will be ignored,
which may be used for commenting. A line
ending with a backslash will be concatenated
with the following one, allowing multiline variable
definitions. The parser strips leading
and trailing whitespace from the values
of assignments, unless you use
double quotes (").</p><p>The argument passed should be an
absolute filename or wildcard
expression, optionally prefixed with
"<code class="literal">-</code>", which indicates
that if the file does not exist, it
will not be read and no error or warning
message is logged. This option may be
specified more than once in which case
all specified files are read. If the
empty string is assigned to this
option, the list of file to read is
reset, all prior assignments have no
effect.</p><p>The files listed with this
directive will be read shortly before
the process is executed (more
specifically, after all
processes from a previous unit state
terminated. This means you can
generate these files in one unit
state, and read it with this option in
the next). Settings from these files
override settings made with
<code class="varname">Environment=</code>. If
the same variable is set twice from
these files, the files will be read in
the order they are specified and the
later setting will override the
earlier setting.</p></dd><dt id="StandardInput="><span class="term"><code class="varname">StandardInput=</code></span><a class="headerlink" title="Permalink to this term" href="#StandardInput=">¶</a></dt><dd><p>Controls where file
descriptor 0 (STDIN) of the executed
processes is connected to. Takes one
of <code class="option">null</code>,
<code class="option">tty</code>,
<code class="option">tty-force</code>,
<code class="option">tty-fail</code> or
<code class="option">socket</code>. If
<code class="option">null</code> is selected,
standard input will be connected to
<code class="filename">/dev/null</code>,
i.e. all read attempts by the process
will result in immediate EOF. If
<code class="option">tty</code> is selected,
standard input is connected to a TTY
(as configured by
<code class="varname">TTYPath=</code>, see
below) and the executed process
becomes the controlling process of the
terminal. If the terminal is already
being controlled by another process, the
executed process waits until the current
controlling process releases the
terminal.
<code class="option">tty-force</code>
is similar to <code class="option">tty</code>,
but the executed process is forcefully
and immediately made the controlling
process of the terminal, potentially
removing previous controlling
processes from the
terminal. <code class="option">tty-fail</code> is
similar to <code class="option">tty</code> but if
the terminal already has a controlling
process start-up of the executed
process fails. The
<code class="option">socket</code> option is only
valid in socket-activated services,
and only when the socket configuration
file (see
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>
for details) specifies a single socket
only. If this option is set, standard
input will be connected to the socket
the service was activated from, which
is primarily useful for compatibility
with daemons designed for use with the
traditional
<a href="inetd.html"><span class="citerefentry"><span class="refentrytitle">inetd</span>(8)</span></a>
daemon. This setting defaults to
<code class="option">null</code>.</p></dd><dt id="StandardOutput="><span class="term"><code class="varname">StandardOutput=</code></span><a class="headerlink" title="Permalink to this term" href="#StandardOutput=">¶</a></dt><dd><p>Controls where file
descriptor 1 (STDOUT) of the executed
processes is connected to. Takes one
of <code class="option">inherit</code>,
<code class="option">null</code>,
<code class="option">tty</code>,
<code class="option">syslog</code>,
<code class="option">kmsg</code>,
<code class="option">journal</code>,
<code class="option">syslog+console</code>,
<code class="option">kmsg+console</code>,
<code class="option">journal+console</code> or
<code class="option">socket</code>. If set to
<code class="option">inherit</code>, the file
descriptor of standard input is
duplicated for standard output. If set
to <code class="option">null</code>, standard
output will be connected to
<code class="filename">/dev/null</code>,
i.e. everything written to it will be
lost. If set to <code class="option">tty</code>,
standard output will be connected to a
tty (as configured via
<code class="varname">TTYPath=</code>, see
below). If the TTY is used for output
only, the executed process will not
become the controlling process of the
terminal, and will not fail or wait
for other processes to release the
terminal. <code class="option">syslog</code>
connects standard output to the
<a href="syslog.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(3)</span></a>
system syslog
service. <code class="option">kmsg</code>
connects it with the kernel log buffer
which is accessible via
<a href="dmesg.html"><span class="citerefentry"><span class="refentrytitle">dmesg</span>(1)</span></a>. <code class="option">journal</code>
connects it with the journal which is
accessible via
<a href="journalctl.html"><span class="citerefentry"><span class="refentrytitle">journalctl</span>(1)</span></a>
(Note that everything that is written
to syslog or kmsg is implicitly stored
in the journal as well, those options
are hence supersets of this
one). <code class="option">syslog+console</code>,
<code class="option">journal+console</code> and
<code class="option">kmsg+console</code> work
similarly but copy the output to the
system console as
well. <code class="option">socket</code> connects
standard output to a socket from
socket activation, semantics are
similar to the respective option of
<code class="varname">StandardInput=</code>.
This setting defaults to the value set
with
<code class="option">DefaultStandardOutput=</code>
in
<a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>,
which defaults to
<code class="option">journal</code>.</p></dd><dt id="StandardError="><span class="term"><code class="varname">StandardError=</code></span><a class="headerlink" title="Permalink to this term" href="#StandardError=">¶</a></dt><dd><p>Controls where file
descriptor 2 (STDERR) of the
executed processes is connected to.
The available options are identical to
those of
<code class="varname">StandardOutput=</code>,
with one exception: if set to
<code class="option">inherit</code> the file
descriptor used for standard output is
duplicated for standard error. This
setting defaults to the value set with
<code class="option">DefaultStandardError=</code>
in
<a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>,
which defaults to
<code class="option">inherit</code>.</p></dd><dt id="TTYPath="><span class="term"><code class="varname">TTYPath=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYPath=">¶</a></dt><dd><p>Sets the terminal
device node to use if standard input, output,
or error are connected to a
TTY (see above). Defaults to
<code class="filename">/dev/console</code>.</p></dd><dt id="TTYReset="><span class="term"><code class="varname">TTYReset=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYReset=">¶</a></dt><dd><p>Reset the terminal
device specified with
<code class="varname">TTYPath=</code> before and
after execution. Defaults to
"<code class="literal">no</code>".</p></dd><dt id="TTYVHangup="><span class="term"><code class="varname">TTYVHangup=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVHangup=">¶</a></dt><dd><p>Disconnect all clients
which have opened the terminal device
specified with
<code class="varname">TTYPath=</code>
before and after execution. Defaults
to
"<code class="literal">no</code>".</p></dd><dt id="TTYVTDisallocate="><span class="term"><code class="varname">TTYVTDisallocate=</code></span><a class="headerlink" title="Permalink to this term" href="#TTYVTDisallocate=">¶</a></dt><dd><p>If the terminal
device specified with
<code class="varname">TTYPath=</code> is a
virtual console terminal, try to
deallocate the TTY before and after
execution. This ensures that the
screen and scrollback buffer is
cleared. Defaults to
"<code class="literal">no</code>".</p></dd><dt id="SyslogIdentifier="><span class="term"><code class="varname">SyslogIdentifier=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogIdentifier=">¶</a></dt><dd><p>Sets the process name
to prefix log lines sent to syslog or
the kernel log buffer with. If not set,
defaults to the process name of the
executed process. This option is only
useful when
<code class="varname">StandardOutput=</code> or
<code class="varname">StandardError=</code> are
set to <code class="option">syslog</code> or
<code class="option">kmsg</code>.</p></dd><dt id="SyslogFacility="><span class="term"><code class="varname">SyslogFacility=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogFacility=">¶</a></dt><dd><p>Sets the syslog
facility to use when logging to
syslog. One of <code class="option">kern</code>,
<code class="option">user</code>,
<code class="option">mail</code>,
<code class="option">daemon</code>,
<code class="option">auth</code>,
<code class="option">syslog</code>,
<code class="option">lpr</code>,
<code class="option">news</code>,
<code class="option">uucp</code>,
<code class="option">cron</code>,
<code class="option">authpriv</code>,
<code class="option">ftp</code>,
<code class="option">local0</code>,
<code class="option">local1</code>,
<code class="option">local2</code>,
<code class="option">local3</code>,
<code class="option">local4</code>,
<code class="option">local5</code>,
<code class="option">local6</code> or
<code class="option">local7</code>. See
<a href="syslog.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(3)</span></a>
for details. This option is only
useful when
<code class="varname">StandardOutput=</code> or
<code class="varname">StandardError=</code> are
set to <code class="option">syslog</code>.
Defaults to
<code class="option">daemon</code>.</p></dd><dt id="SyslogLevel="><span class="term"><code class="varname">SyslogLevel=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogLevel=">¶</a></dt><dd><p>Default syslog level
to use when logging to syslog or the
kernel log buffer. One of
<code class="option">emerg</code>,
<code class="option">alert</code>,
<code class="option">crit</code>,
<code class="option">err</code>,
<code class="option">warning</code>,
<code class="option">notice</code>,
<code class="option">info</code>,
<code class="option">debug</code>. See
<a href="syslog.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(3)</span></a>
for details. This option is only
useful when
<code class="varname">StandardOutput=</code> or
<code class="varname">StandardError=</code> are
set to <code class="option">syslog</code> or
<code class="option">kmsg</code>. Note that
individual lines output by the daemon
might be prefixed with a different log
level which can be used to override
the default log level specified
here. The interpretation of these
prefixes may be disabled with
<code class="varname">SyslogLevelPrefix=</code>,
see below. For details see
<a href="sd-daemon.html"><span class="citerefentry"><span class="refentrytitle">sd-daemon</span>(3)</span></a>.
Defaults to
<code class="option">info</code>.</p></dd><dt id="SyslogLevelPrefix="><span class="term"><code class="varname">SyslogLevelPrefix=</code></span><a class="headerlink" title="Permalink to this term" href="#SyslogLevelPrefix=">¶</a></dt><dd><p>Takes a boolean
argument. If true and
<code class="varname">StandardOutput=</code> or
<code class="varname">StandardError=</code> are
set to <code class="option">syslog</code>,
<code class="option">kmsg</code> or
<code class="option">journal</code>, log lines
written by the executed process that
are prefixed with a log level will be
passed on to syslog with this log
level set but the prefix removed. If
set to false, the interpretation of
these prefixes is disabled and the
logged lines are passed on as-is. For
details about this prefixing see
<a href="sd-daemon.html"><span class="citerefentry"><span class="refentrytitle">sd-daemon</span>(3)</span></a>.
Defaults to true.</p></dd><dt id="TimerSlackNSec="><span class="term"><code class="varname">TimerSlackNSec=</code></span><a class="headerlink" title="Permalink to this term" href="#TimerSlackNSec=">¶</a></dt><dd><p>Sets the timer slack
in nanoseconds for the executed
processes. The timer slack controls
the accuracy of wake-ups triggered by
timers. See
<a href="prctl.html"><span class="citerefentry"><span class="refentrytitle">prctl</span>(2)</span></a>
for more information. Note that in
contrast to most other time span
definitions this parameter takes an
integer value in nano-seconds if no
unit is specified. The usual time
units are understood
too.</p></dd><dt id="LimitCPU="><span class="term"><code class="varname">LimitCPU=</code>, </span><span class="term"><code class="varname">LimitFSIZE=</code>, </span><span class="term"><code class="varname">LimitDATA=</code>, </span><span class="term"><code class="varname">LimitSTACK=</code>, </span><span class="term"><code class="varname">LimitCORE=</code>, </span><span class="term"><code class="varname">LimitRSS=</code>, </span><span class="term"><code class="varname">LimitNOFILE=</code>, </span><span class="term"><code class="varname">LimitAS=</code>, </span><span class="term"><code class="varname">LimitNPROC=</code>, </span><span class="term"><code class="varname">LimitMEMLOCK=</code>, </span><span class="term"><code class="varname">LimitLOCKS=</code>, </span><span class="term"><code class="varname">LimitSIGPENDING=</code>, </span><span class="term"><code class="varname">LimitMSGQUEUE=</code>, </span><span class="term"><code class="varname">LimitNICE=</code>, </span><span class="term"><code class="varname">LimitRTPRIO=</code>, </span><span class="term"><code class="varname">LimitRTTIME=</code></span><a class="headerlink" title="Permalink to this term" href="#LimitCPU=">¶</a></dt><dd><p>These settings control
various resource limits for executed
processes. See
<a href="setrlimit.html"><span class="citerefentry"><span class="refentrytitle">setrlimit</span>(2)</span></a>
for details. Use the string
<code class="varname">infinity</code> to
configure no limit on a specific
resource.</p></dd><dt id="PAMName="><span class="term"><code class="varname">PAMName=</code></span><a class="headerlink" title="Permalink to this term" href="#PAMName=">¶</a></dt><dd><p>Sets the PAM service
name to set up a session as. If set,
the executed process will be
registered as a PAM session under the
specified service name. This is only
useful in conjunction with the
<code class="varname">User=</code> setting. If
not set, no PAM session will be opened
for the executed processes. See
<a href="pam.html"><span class="citerefentry"><span class="refentrytitle">pam</span>(8)</span></a>
for details.</p></dd><dt id="CapabilityBoundingSet="><span class="term"><code class="varname">CapabilityBoundingSet=</code></span><a class="headerlink" title="Permalink to this term" href="#CapabilityBoundingSet=">¶</a></dt><dd><p>Controls which
capabilities to include in the
capability bounding set for the
executed process. See
<a href="capabilities.html"><span class="citerefentry"><span class="refentrytitle">capabilities</span>(7)</span></a>
for details. Takes a whitespace-separated
list of capability names as read by
<a href="cap_from_name.html"><span class="citerefentry"><span class="refentrytitle">cap_from_name</span>(3)</span></a>,
e.g. <code class="constant">CAP_SYS_ADMIN</code>,
<code class="constant">CAP_DAC_OVERRIDE</code>,
<code class="constant">CAP_SYS_PTRACE</code>.
Capabilities listed will be included
in the bounding set, all others are
removed. If the list of capabilities
is prefixed with "<code class="literal">~</code>",
all but the listed capabilities will
be included, the effect of the
assignment inverted. Note that this
option also affects the respective
capabilities in the effective,
permitted and inheritable capability
sets, on top of what
<code class="varname">Capabilities=</code>
does. If this option is not used, the
capability bounding set is not
modified on process execution, hence
no limits on the capabilities of the
process are enforced. This option may
appear more than once in which case
the bounding sets are merged. If the
empty string is assigned to this
option, the bounding set is reset to
the empty capability set, and all
prior settings have no effect. If set
to "<code class="literal">~</code>" (without any
further argument), the bounding set is
reset to the full set of available
capabilities, also undoing any
previous settings.</p></dd><dt id="SecureBits="><span class="term"><code class="varname">SecureBits=</code></span><a class="headerlink" title="Permalink to this term" href="#SecureBits=">¶</a></dt><dd><p>Controls the secure
bits set for the executed process. See
<a href="capabilities.html"><span class="citerefentry"><span class="refentrytitle">capabilities</span>(7)</span></a>
for details. Takes a list of strings:
<code class="option">keep-caps</code>,
<code class="option">keep-caps-locked</code>,
<code class="option">no-setuid-fixup</code>,
<code class="option">no-setuid-fixup-locked</code>,
<code class="option">noroot</code> and/or
<code class="option">noroot-locked</code>. This
option may appear more than once in
which case the secure bits are
ORed. If the empty string is assigned
to this option, the bits are reset to
0.</p></dd><dt id="Capabilities="><span class="term"><code class="varname">Capabilities=</code></span><a class="headerlink" title="Permalink to this term" href="#Capabilities=">¶</a></dt><dd><p>Controls the
<a href="capabilities.html"><span class="citerefentry"><span class="refentrytitle">capabilities</span>(7)</span></a>
set for the executed process. Take a
capability string describing the
effective, permitted and inherited
capability sets as documented in
<a href="cap_from_text.html"><span class="citerefentry"><span class="refentrytitle">cap_from_text</span>(3)</span></a>.
Note that these capability sets are
usually influenced (and filtered) by the capabilities
attached to the executed file. Due to
that
<code class="varname">CapabilityBoundingSet=</code>
is probably the much more useful
setting.</p></dd><dt id="ReadWriteDirectories="><span class="term"><code class="varname">ReadWriteDirectories=</code>, </span><span class="term"><code class="varname">ReadOnlyDirectories=</code>, </span><span class="term"><code class="varname">InaccessibleDirectories=</code></span><a class="headerlink" title="Permalink to this term" href="#ReadWriteDirectories=">¶</a></dt><dd><p>Sets up a new file
system namespace for executed
processes. These options may be used
to limit access a process might have
to the main file system
hierarchy. Each setting takes a
space-separated list of absolute
directory paths. Directories listed in
<code class="varname">ReadWriteDirectories=</code>
are accessible from within the
namespace with the same access rights
as from outside. Directories listed in
<code class="varname">ReadOnlyDirectories=</code>
are accessible for reading only,
writing will be refused even if the
usual file access controls would
permit this. Directories listed in
<code class="varname">InaccessibleDirectories=</code>
will be made inaccessible for
processes inside the namespace. Note
that restricting access with these
options does not extend to submounts
of a directory that are created later
on. These options may be specified
more than once in which case all
directories listed will have limited
access from within the namespace. If
the empty string is assigned to this
option, the specific list is reset,
and all prior assignments have no
effect.</p><p>Paths in
<code class="varname">ReadOnlyDirectories=</code>
and
<code class="varname">InaccessibleDirectories=</code>
may be prefixed with
"<code class="literal">-</code>", in which case
they will be ignored when they do not
exist. Note that using this
setting will disconnect propagation of
mounts from the service to the host
(propagation in the opposite direction
continues to work). This means that
this setting may not be used for
services which shall be able to
install mount points in the main mount
namespace.</p></dd><dt id="PrivateTmp="><span class="term"><code class="varname">PrivateTmp=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateTmp=">¶</a></dt><dd><p>Takes a boolean
argument. If true, sets up a new file
system namespace for the executed
processes and mounts private
<code class="filename">/tmp</code> and
<code class="filename">/var/tmp</code>
directories inside it that is not
shared by processes outside of the
namespace. This is useful to secure
access to temporary files of the
process, but makes sharing between
processes via
<code class="filename">/tmp</code> or
<code class="filename">/var/tmp</code>
impossible. If this is enabled, all
temporary files created by a service
in these directories will be removed
after the service is stopped. Defaults
to false. It is possible to run two or
more units within the same private
<code class="filename">/tmp</code> and
<code class="filename">/var/tmp</code>
namespace by using the
<code class="varname">JoinsNamespaceOf=</code>
directive, see
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>
for details. Note that using this
setting will disconnect propagation of
mounts from the service to the host
(propagation in the opposite direction
continues to work). This means that
this setting may not be used for
services which shall be able to install
mount points in the main mount
namespace.</p></dd><dt id="PrivateDevices="><span class="term"><code class="varname">PrivateDevices=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateDevices=">¶</a></dt><dd><p>Takes a boolean
argument. If true, sets up a new /dev
namespace for the executed processes
and only adds API pseudo devices such
as <code class="filename">/dev/null</code>,
<code class="filename">/dev/zero</code> or
<code class="filename">/dev/random</code> (as
well as the pseudo TTY subsystem) to
it, but no physical devices such as
<code class="filename">/dev/sda</code>. This is
useful to securely turn off physical
device access by the executed
process. Defaults to false. Enabling
this option will also remove
<code class="constant">CAP_MKNOD</code> from
the capability bounding set for the
unit (see above), and set
<code class="varname">DevicePolicy=closed</code>
(see
<a href="systemd.resource-control.html"><span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span></a>
for details). Note that using this
setting will disconnect propagation of
mounts from the service to the host
(propagation in the opposite direction
continues to work). This means that
this setting may not be used for
services which shall be able to
install mount points in the main mount
namespace.</p></dd><dt id="PrivateNetwork="><span class="term"><code class="varname">PrivateNetwork=</code></span><a class="headerlink" title="Permalink to this term" href="#PrivateNetwork=">¶</a></dt><dd><p>Takes a boolean
argument. If true, sets up a new
network namespace for the executed
processes and configures only the
loopback network device
"<code class="literal">lo</code>" inside it. No
other network devices will be
available to the executed process.
This is useful to securely turn off
network access by the executed
process. Defaults to false. It is
possible to run two or more units
within the same private network
namespace by using the
<code class="varname">JoinsNamespaceOf=</code>
directive, see
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>
for details. Note that this option
will disconnect all socket families
from the host, this includes
AF_NETLINK and AF_UNIX. The latter has
the effect that AF_UNIX sockets in the
abstract socket namespace will become
unavailable to the processes (however,
those located in the file system will
continue to be
accessible).</p></dd><dt id="ProtectSystem="><span class="term"><code class="varname">ProtectSystem=</code></span><a class="headerlink" title="Permalink to this term" href="#ProtectSystem=">¶</a></dt><dd><p>Takes a boolean
argument or
"<code class="literal">full</code>". If true,
mounts the <code class="filename">/usr</code>
directory read-only for processes
invoked by this unit. If set to
"<code class="literal">full</code>", the
<code class="filename">/etc</code> directory is mounted
read-only, too. This setting ensures
that any modification of the vendor
supplied operating system (and
optionally its configuration) is
prohibited for the service. It is
recommended to enable this setting for
all long-running services, unless they
are involved with system updates or
need to modify the operating system in
other ways. Note however that
processes retaining the CAP_SYS_ADMIN
capability can undo the effect of this
setting. This setting is hence
particularly useful for daemons which
have this capability removed, for
example with
<code class="varname">CapabilityBoundingSet=</code>. Defaults
to off.</p></dd><dt id="ProtectHome="><span class="term"><code class="varname">ProtectHome=</code></span><a class="headerlink" title="Permalink to this term" href="#ProtectHome=">¶</a></dt><dd><p>Takes a boolean
argument or
"<code class="literal">read-only</code>". If true,
the directories
<code class="filename">/home</code> and
<code class="filename">/run/user</code> are
made inaccessible and empty for
processes invoked by this unit. If set
to "<code class="literal">read-only</code>", the
two directores are made read-only
instead. It is recommended to enable
this setting for all long-running
services (in particular network-facing
ones), to ensure they cannot get access
to private user data, unless the
services actually require access to
the user's private data. Note however
that processes retaining the
CAP_SYS_ADMIN capability can undo the
effect of this setting. This setting
is hence particularly useful for
daemons which have this capability
removed, for example with
<code class="varname">CapabilityBoundingSet=</code>. Defaults
to off.</p></dd><dt id="MountFlags="><span class="term"><code class="varname">MountFlags=</code></span><a class="headerlink" title="Permalink to this term" href="#MountFlags=">¶</a></dt><dd><p>Takes a mount
propagation flag:
<code class="option">shared</code>,
<code class="option">slave</code> or
<code class="option">private</code>, which
control whether mounts in the file
system namespace set up for this
unit's processes will receive or
propagate mounts or unmounts. See
<a href="mount.html"><span class="citerefentry"><span class="refentrytitle">mount</span>(2)</span></a>
for details. Defaults to
<code class="option">shared</code>. Use
<code class="option">shared</code> to ensure that
mounts and unmounts are propagated
from the host to the container and
vice versa. Use <code class="option">slave</code>
to run processes so that none of their
mounts and unmounts will propagate to
the host. Use <code class="option">private</code>
to also ensure that no mounts and
unmounts from the host will propagate
into the unit processes'
namespace. Note that
<code class="option">slave</code> means that file
systems mounted on the host might stay
mounted continously in the unit's
namespace, and thus keep the device
busy. Note that the file system
namespace related options
(<code class="varname">PrivateTmp=</code>,
<code class="varname">PrivateDevices=</code>,
<code class="varname">ReadOnlySystem=</code>,
<code class="varname">ProtectedHome=</code>,
<code class="varname">ReadOnlyDirectories=</code>,
<code class="varname">InaccessibleDirectories=</code>
and
<code class="varname">ReadWriteDirectories=</code>)
require that mount and unmount
propagation from the unit's file
system namespace is disabled, and
hence downgrade
<code class="option">shared</code> to
<code class="option">slave</code>.
</p></dd><dt id="UtmpIdentifier="><span class="term"><code class="varname">UtmpIdentifier=</code></span><a class="headerlink" title="Permalink to this term" href="#UtmpIdentifier=">¶</a></dt><dd><p>Takes a four
character identifier string for an
utmp/wtmp entry for this service. This
should only be set for services such
as <span class="command"><strong>getty</strong></span>
implementations where utmp/wtmp
entries must be created and cleared
before and after execution. If the
configured string is longer than four
characters, it is truncated and the
terminal four characters are
used. This setting interprets %I style
string replacements. This setting is
unset by default, i.e. no utmp/wtmp
entries are created or cleaned up for
this service.</p></dd><dt id="SELinuxContext="><span class="term"><code class="varname">SELinuxContext=</code></span><a class="headerlink" title="Permalink to this term" href="#SELinuxContext=">¶</a></dt><dd><p>Set the SELinux
security context of the executed
process. If set, this will override
the automated domain
transition. However, the policy still
needs to autorize the transition. This
directive is ignored if SELinux is
disabled. If prefixed by
"<code class="literal">-</code>", all errors will
be ignored. See
<a href="setexeccon.html"><span class="citerefentry"><span class="refentrytitle">setexeccon</span>(3)</span></a>
for details.</p></dd><dt id="AppArmorProfile="><span class="term"><code class="varname">AppArmorProfile=</code></span><a class="headerlink" title="Permalink to this term" href="#AppArmorProfile=">¶</a></dt><dd><p>Takes a profile name as argument.
The process executed by the unit will switch to
this profile when started. Profiles must already
be loaded in the kernel, or the unit will fail.
This result in a non operation if AppArmor is not
enabled. If prefixed by "<code class="literal">-</code>", all errors
will be ignored.
</p></dd><dt id="IgnoreSIGPIPE="><span class="term"><code class="varname">IgnoreSIGPIPE=</code></span><a class="headerlink" title="Permalink to this term" href="#IgnoreSIGPIPE=">¶</a></dt><dd><p>Takes a boolean
argument. If true, causes <code class="constant">SIGPIPE</code> to be
ignored in the executed
process. Defaults to true because
<code class="constant">SIGPIPE</code> generally is useful only in
shell pipelines.</p></dd><dt id="NoNewPrivileges="><span class="term"><code class="varname">NoNewPrivileges=</code></span><a class="headerlink" title="Permalink to this term" href="#NoNewPrivileges=">¶</a></dt><dd><p>Takes a boolean
argument. If true, ensures that the
service process and all its children
can never gain new privileges. This
option is more powerful than the respective
secure bits flags (see above), as it
also prohibits UID changes of any
kind. This is the simplest, most
effective way to ensure that a process
and its children can never elevate
privileges again.</p></dd><dt id="SystemCallFilter="><span class="term"><code class="varname">SystemCallFilter=</code></span><a class="headerlink" title="Permalink to this term" href="#SystemCallFilter=">¶</a></dt><dd><p>Takes a
space-separated list of system call
names. If this setting is used, all
system calls executed by the unit
processes except for the listed ones
will result in immediate process
termination with the
<code class="constant">SIGSYS</code> signal
(whitelisting). If the first character
of the list is "<code class="literal">~</code>",
the effect is inverted: only the
listed system calls will result in
immediate process termination
(blacklisting). If running in user
mode and this option is used,
<code class="varname">NoNewPrivileges=yes</code>
is implied. This feature makes use of the
Secure Computing Mode 2 interfaces of
the kernel ('seccomp filtering') and
is useful for enforcing a minimal
sandboxing environment. Note that the
<code class="function">execve</code>,
<code class="function">rt_sigreturn</code>,
<code class="function">sigreturn</code>,
<code class="function">exit_group</code>,
<code class="function">exit</code> system calls
are implicitly whitelisted and do not
need to be listed explicitly. This
option may be specified more than once
in which case the filter masks are
merged. If the empty string is
assigned, the filter is reset, all
prior assignments will have no
effect.</p><p>If you specify both types of
this option (i.e. whitelisting and
blacklisting), the first encountered
will take precedence and will dictate
the default action (termination or
approval of a system call). Then the
next occurrences of this option will
add or delete the listed system calls
from the set of the filtered system
calls, depending of its type and the
default action. (For example, if you have started
with a whitelisting of
<code class="function">read</code> and
<code class="function">write</code>, and right
after it add a blacklisting of
<code class="function">write</code>, then
<code class="function">write</code> will be
removed from the set.)
</p></dd><dt id="SystemCallErrorNumber="><span class="term"><code class="varname">SystemCallErrorNumber=</code></span><a class="headerlink" title="Permalink to this term" href="#SystemCallErrorNumber=">¶</a></dt><dd><p>Takes an
"<code class="literal">errno</code>" error number
name to return when the system call
filter configured with
<code class="varname">SystemCallFilter=</code>
is triggered, instead of terminating
the process immediately. Takes an
error name such as
<code class="constant">EPERM</code>,
<code class="constant">EACCES</code> or
<code class="constant">EUCLEAN</code>. When this
setting is not used, or when the empty
string is assigned, the process will be
terminated immediately when the filter
is triggered.</p></dd><dt id="SystemCallArchitectures="><span class="term"><code class="varname">SystemCallArchitectures=</code></span><a class="headerlink" title="Permalink to this term" href="#SystemCallArchitectures=">¶</a></dt><dd><p>Takes a space
separated list of architecture
identifiers to include in the system
call filter. The known architecture
identifiers are
<code class="constant">x86</code>,
<code class="constant">x86-64</code>,
<code class="constant">x32</code>,
<code class="constant">arm</code> as well as
the special identifier
<code class="constant">native</code>. Only
system calls of the specified
architectures will be permitted to
processes of this unit. This is an
effective way to disable compatibility
with non-native architectures for
processes, for example to prohibit
execution of 32-bit x86 binaries on
64-bit x86-64 systems. The special
<code class="constant">native</code> identifier
implicitly maps to the native
architecture of the system (or more
strictly: to the architecture the
system manager is compiled for). If
running in user mode and this option
is used,
<code class="varname">NoNewPrivileges=yes</code>
is implied. Note that setting this
option to a non-empty list implies
that <code class="constant">native</code> is
included too. By default, this option
is set to the empty list, i.e. no
architecture system call filtering is
applied.</p></dd><dt id="RestrictAddressFamilies="><span class="term"><code class="varname">RestrictAddressFamilies=</code></span><a class="headerlink" title="Permalink to this term" href="#RestrictAddressFamilies=">¶</a></dt><dd><p>Restricts the set of
socket address families accessible to
the processes of this unit. Takes a
space-separated list of address family
names to whitelist, such as
<code class="constant">AF_UNIX</code>,
<code class="constant">AF_INET</code> or
<code class="constant">AF_INET6</code>. When
prefixed with <code class="constant">~</code>
the listed address families will be
applied as blacklist, otherwise as
whitelist. Note that this restricts
access to the
<a href="socket.html"><span class="citerefentry"><span class="refentrytitle">socket</span>(2)</span></a>
system call only. Sockets passed into
the process by other means (for
example, by using socket activation
with socket units, see
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>)
are unaffected. Also, sockets created
with <code class="function">socketpair()</code>
(which creates connected AF_UNIX
sockets only) are unaffected. Note
that this option has no effect on
32-bit x86 and is ignored (but works
correctly on x86-64). If running in user
mode and this option is used,
<code class="varname">NoNewPrivileges=yes</code>
is implied. By default, no
restriction applies, all address
families are accessible to
processes. If assigned the empty
string, any previous list changes are
undone.</p><p>Use this option to limit
exposure of processes to remote
systems, in particular via exotic
network protocols. Note that in most
cases, the local
<code class="constant">AF_UNIX</code> address
family should be included in the
configured whitelist as it is
frequently used for local
communication, including for
<a href="syslog.html"><span class="citerefentry"><span class="refentrytitle">syslog</span>(2)</span></a>
logging.</p></dd><dt id="Personality="><span class="term"><code class="varname">Personality=</code></span><a class="headerlink" title="Permalink to this term" href="#Personality=">¶</a></dt><dd><p>Controls which
kernel architecture
<a href="uname.html"><span class="citerefentry"><span class="refentrytitle">uname</span>(2)</span></a>
shall report, when invoked by unit
processes. Takes one of
<code class="constant">x86</code> and
<code class="constant">x86-64</code>. This is
useful when running 32-bit services on
a 64-bit host system. If not specified,
the personality is left unmodified and
thus reflects the personality of the
host system's
kernel.</p></dd><dt id="RuntimeDirectory="><span class="term"><code class="varname">RuntimeDirectory=</code>, </span><span class="term"><code class="varname">RuntimeDirectoryMode=</code></span><a class="headerlink" title="Permalink to this term" href="#RuntimeDirectory=">¶</a></dt><dd><p>Takes a list of
directory names. If set, one or more
directories by the specified names
will be created below
<code class="filename">/run</code> (for system
services) or below
<code class="varname">$XDG_RUNTIME_DIR</code>
(for user services) when the unit is
started, and removed when the unit is
stopped. The directories will have the
access mode specified in
<code class="varname">RuntimeDirectoryMode=</code>,
and will be owned by the user and
group specified in
<code class="varname">User=</code> and
<code class="varname">Group=</code>. Use this to
manage one or more runtime directories
of the unit and bind their lifetime to
the daemon runtime. The specified
directory names must be relative, and
may not include a
"<code class="literal">/</code>", i.e. must refer
to simple directories to create or
remove. This is particularly useful
for unprivileged daemons that cannot
create runtime directories in
<code class="filename">/run</code> due to lack
of privileges, and to make sure the
runtime directory is cleaned up
automatically after use. For runtime
directories that require more complex
or different configuration or lifetime
guarantees, please consider using
<a href="tmpfiles.d.html"><span class="citerefentry"><span class="refentrytitle">tmpfiles.d</span>(5)</span></a>.</p></dd></dl></div></div><div class="refsect1"><a name="idm214175926544"></a><h2 id="Environment variables in spawned processes">Environment variables in spawned processes<a class="headerlink" title="Permalink to this headline" href="#Environment%20variables%20in%20spawned%20processes">¶</a></h2><p>Processes started by the system are executed in
a clean environment in which select variables
listed below are set. System processes started by systemd
do not inherit variables from PID 1, but processes
started by user systemd instances inherit all
environment variables from the user systemd instance.
</p><div class="variablelist"><dl class="variablelist"><dt id="$PATH"><span class="term"><code class="varname">$PATH</code></span><a class="headerlink" title="Permalink to this term" href="#%24PATH">¶</a></dt><dd><p>Colon-separated list
of directiories to use when launching
executables. Systemd uses a fixed
value of
<code class="filename">/usr/local/sbin</code>:<code class="filename">/usr/local/bin</code>:<code class="filename">/usr/sbin</code>:<code class="filename">/usr/bin</code>:<code class="filename">/sbin</code>:<code class="filename">/bin</code>.
</p></dd><dt id="$LANG"><span class="term"><code class="varname">$LANG</code></span><a class="headerlink" title="Permalink to this term" href="#%24LANG">¶</a></dt><dd><p>Locale. Can be set in
<a href="locale.conf.html"><span class="citerefentry"><span class="refentrytitle">locale.conf</span>(5)</span></a>
or on the kernel command line (see
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>
and
<a href="kernel-command-line.html"><span class="citerefentry"><span class="refentrytitle">kernel-command-line</span>(7)</span></a>).
</p></dd><dt id="$USER"><span class="term"><code class="varname">$USER</code>, </span><span class="term"><code class="varname">$LOGNAME</code>, </span><span class="term"><code class="varname">$HOME</code>, </span><span class="term"><code class="varname">$SHELL</code></span><a class="headerlink" title="Permalink to this term" href="#%24USER">¶</a></dt><dd><p>User name (twice), home
directory, and the login shell.
The variables are set for the units that
have <code class="varname">User=</code> set,
which includes user
<span class="command"><strong>systemd</strong></span> instances.
See
<a href="passwd.html"><span class="citerefentry"><span class="refentrytitle">passwd</span>(5)</span></a>.
</p></dd><dt id="$XDG_RUNTIME_DIR"><span class="term"><code class="varname">$XDG_RUNTIME_DIR</code></span><a class="headerlink" title="Permalink to this term" href="#%24XDG_RUNTIME_DIR">¶</a></dt><dd><p>The directory for volatile
state. Set for the user <span class="command"><strong>systemd</strong></span>
instance, and also in user sessions.
See
<a href="pam_systemd.html"><span class="citerefentry"><span class="refentrytitle">pam_systemd</span>(8)</span></a>.
</p></dd><dt id="$XDG_SESSION_ID"><span class="term"><code class="varname">$XDG_SESSION_ID</code>, </span><span class="term"><code class="varname">$XDG_SEAT</code>, </span><span class="term"><code class="varname">$XDG_VTNR</code></span><a class="headerlink" title="Permalink to this term" href="#%24XDG_SESSION_ID">¶</a></dt><dd><p>The identifier of the
session, the seat name, and
virtual terminal of the session. Set
by
<a href="pam_systemd.html"><span class="citerefentry"><span class="refentrytitle">pam_systemd</span>(8)</span></a>
for login sessions.
<code class="varname">$XDG_SEAT</code> and
<code class="varname">$XDG_VTNR</code> will
only be set when attached to a seat and a
tty.</p></dd><dt id="$MAINPID"><span class="term"><code class="varname">$MAINPID</code></span><a class="headerlink" title="Permalink to this term" href="#%24MAINPID">¶</a></dt><dd><p>The PID of the units
main process if it is known. This is
only set for control processes as
invoked by
<code class="varname">ExecReload=</code> and
similar. </p></dd><dt id="$MANAGERPID"><span class="term"><code class="varname">$MANAGERPID</code></span><a class="headerlink" title="Permalink to this term" href="#%24MANAGERPID">¶</a></dt><dd><p>The PID of the user
<span class="command"><strong>systemd</strong></span> instance,
set for processes spawned by it.
</p></dd><dt id="$LISTEN_FDS"><span class="term"><code class="varname">$LISTEN_FDS</code>, </span><span class="term"><code class="varname">$LISTEN_PID</code></span><a class="headerlink" title="Permalink to this term" href="#%24LISTEN_FDS">¶</a></dt><dd><p>Information about file
descriptors passed to a service for
socket activation. See
<a href="sd_listen_fds.html"><span class="citerefentry"><span class="refentrytitle">sd_listen_fds</span>(3)</span></a>.
</p></dd><dt id="$TERM"><span class="term"><code class="varname">$TERM</code></span><a class="headerlink" title="Permalink to this term" href="#%24TERM">¶</a></dt><dd><p>Terminal type, set
only for units connected to a terminal
(<code class="varname">StandardInput=tty</code>,
<code class="varname">StandardOutput=tty</code>,
or
<code class="varname">StandardError=tty</code>).
See
<a href="termcap.html"><span class="citerefentry"><span class="refentrytitle">termcap</span>(5)</span></a>.
</p></dd></dl></div><p>Additional variables may be configured by the
following means: for processes spawned in specific
units, use the <code class="varname">Environment=</code> and
<code class="varname">EnvironmentFile=</code> options above; to
specify variables globally, use
<code class="varname">DefaultEnvironment=</code> (see
<a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>)
or the kernel option
<code class="varname">systemd.setenv=</code> (see
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>). Additional
variables may also be set through PAM,
cf. <a href="pam_env.html"><span class="citerefentry"><span class="refentrytitle">pam_env</span>(8)</span></a>.</p></div><div class="refsect1"><a name="idm214175887296"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
<a href="systemctl.html"><span class="citerefentry"><span class="refentrytitle">systemctl</span>(8)</span></a>,
<a href="journalctl.html"><span class="citerefentry"><span class="refentrytitle">journalctl</span>(8)</span></a>,
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>,
<a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
<a href="systemd.socket.html"><span class="citerefentry"><span class="refentrytitle">systemd.socket</span>(5)</span></a>,
<a href="systemd.swap.html"><span class="citerefentry"><span class="refentrytitle">systemd.swap</span>(5)</span></a>,
<a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a>,
<a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>,
<a href="systemd.resource-control.html"><span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span></a>,
<a href="systemd.directives.html"><span class="citerefentry"><span class="refentrytitle">systemd.directives</span>(7)</span></a>,
<a href="tmpfiles.d.html"><span class="citerefentry"><span class="refentrytitle">tmpfiles.d</span>(5)</span></a>,
<a href="exec.html"><span class="citerefentry"><span class="refentrytitle">exec</span>(3)</span></a>
</p></div></div></body></html>
|
