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023a4f67 | 1 | <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
dd1eb43b | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2010 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
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11 | under the terms of the GNU Lesser General Public License as published by |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
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13 | (at your option) any later version. |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 18 | Lesser General Public License for more details. |
dd1eb43b | 19 | |
5430f7f2 | 20 | You should have received a copy of the GNU Lesser General Public License |
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21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
22 | --> | |
23 | ||
24 | <refentry id="systemd.exec"> | |
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25 | <refentryinfo> |
26 | <title>systemd.exec</title> | |
27 | <productname>systemd</productname> | |
28 | ||
29 | <authorgroup> | |
30 | <author> | |
31 | <contrib>Developer</contrib> | |
32 | <firstname>Lennart</firstname> | |
33 | <surname>Poettering</surname> | |
34 | <email>lennart@poettering.net</email> | |
35 | </author> | |
36 | </authorgroup> | |
37 | </refentryinfo> | |
38 | ||
39 | <refmeta> | |
40 | <refentrytitle>systemd.exec</refentrytitle> | |
41 | <manvolnum>5</manvolnum> | |
42 | </refmeta> | |
43 | ||
44 | <refnamediv> | |
45 | <refname>systemd.exec</refname> | |
46 | <refpurpose>Execution environment configuration</refpurpose> | |
47 | </refnamediv> | |
48 | ||
49 | <refsynopsisdiv> | |
50 | <para><filename><replaceable>service</replaceable>.service</filename>, | |
51 | <filename><replaceable>socket</replaceable>.socket</filename>, | |
52 | <filename><replaceable>mount</replaceable>.mount</filename>, | |
53 | <filename><replaceable>swap</replaceable>.swap</filename></para> | |
54 | </refsynopsisdiv> | |
55 | ||
56 | <refsect1> | |
57 | <title>Description</title> | |
58 | ||
59 | <para>Unit configuration files for services, sockets, mount | |
60 | points, and swap devices share a subset of configuration options | |
61 | which define the execution environment of spawned | |
62 | processes.</para> | |
63 | ||
64 | <para>This man page lists the configuration options shared by | |
65 | these four unit types. See | |
66 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
67 | for the common options of all unit configuration files, and | |
68 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
69 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
70 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
71 | and | |
72 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
73 | for more information on the specific unit configuration files. The | |
74 | execution specific configuration options are configured in the | |
75 | [Service], [Socket], [Mount], or [Swap] sections, depending on the | |
76 | unit type.</para> | |
77 | </refsect1> | |
78 | ||
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79 | <refsect1> |
80 | <title>Automatic Dependencies</title> | |
81 | ||
82 | <para>A few execution parameters result in additional, automatic | |
83 | dependencies to be added.</para> | |
84 | ||
85 | <para>Units with <varname>WorkingDirectory=</varname> or | |
86 | <varname>RootDirectory=</varname> set automatically gain | |
87 | dependencies of type <varname>Requires=</varname> and | |
88 | <varname>After=</varname> on all mount units required to access | |
89 | the specified paths. This is equivalent to having them listed | |
90 | explicitly in <varname>RequiresMountsFor=</varname>.</para> | |
91 | ||
92 | <para>Similar, units with <varname>PrivateTmp=</varname> enabled | |
93 | automatically get mount unit dependencies for all mounts | |
94 | required to access <filename>/tmp</filename> and | |
95 | <filename>/var/tmp</filename>.</para> | |
96 | ||
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97 | <para>Units whose output standard output or error output is connected to <option>journal</option>, |
98 | <option>syslog</option> or <option>kmsg</option> (or their combinations with console output, see below) | |
99 | automatically acquire dependencies of type <varname>After=</varname> on | |
100 | <filename>systemd-journald.socket</filename>.</para> | |
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101 | </refsect1> |
102 | ||
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103 | <refsect1> |
104 | <title>Options</title> | |
105 | ||
106 | <variablelist class='unit-directives'> | |
107 | ||
108 | <varlistentry> | |
109 | <term><varname>WorkingDirectory=</varname></term> | |
110 | ||
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111 | <listitem><para>Takes an absolute directory path, or the |
112 | special value <literal>~</literal>. Sets the working directory | |
b938cb90 | 113 | for executed processes. If set to <literal>~</literal>, the |
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114 | home directory of the user specified in |
115 | <varname>User=</varname> is used. If not set, defaults to the | |
116 | root directory when systemd is running as a system instance | |
117 | and the respective user's home directory if run as user. If | |
118 | the setting is prefixed with the <literal>-</literal> | |
119 | character, a missing working directory is not considered | |
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120 | fatal. Note that setting this parameter might result in |
121 | additional dependencies to be added to the unit (see | |
122 | above).</para></listitem> | |
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123 | </varlistentry> |
124 | ||
125 | <varlistentry> | |
126 | <term><varname>RootDirectory=</varname></term> | |
127 | ||
128 | <listitem><para>Takes an absolute directory path. Sets the | |
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129 | root directory for executed processes, with the <citerefentry |
130 | project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
798d3a52 | 131 | system call. If this is used, it must be ensured that the |
5f5d8eab | 132 | process binary and all its auxiliary files are available in |
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133 | the <function>chroot()</function> jail. Note that setting this |
134 | parameter might result in additional dependencies to be added | |
135 | to the unit (see above).</para></listitem> | |
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136 | </varlistentry> |
137 | ||
138 | <varlistentry> | |
139 | <term><varname>User=</varname></term> | |
140 | <term><varname>Group=</varname></term> | |
141 | ||
142 | <listitem><para>Sets the Unix user or group that the processes | |
143 | are executed as, respectively. Takes a single user or group | |
144 | name or ID as argument. If no group is set, the default group | |
145 | of the user is chosen.</para></listitem> | |
146 | </varlistentry> | |
147 | ||
148 | <varlistentry> | |
149 | <term><varname>SupplementaryGroups=</varname></term> | |
150 | ||
151 | <listitem><para>Sets the supplementary Unix groups the | |
152 | processes are executed as. This takes a space-separated list | |
153 | of group names or IDs. This option may be specified more than | |
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154 | once, in which case all listed groups are set as supplementary |
155 | groups. When the empty string is assigned, the list of | |
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156 | supplementary groups is reset, and all assignments prior to |
157 | this one will have no effect. In any way, this option does not | |
158 | override, but extends the list of supplementary groups | |
159 | configured in the system group database for the | |
160 | user.</para></listitem> | |
161 | </varlistentry> | |
162 | ||
163 | <varlistentry> | |
164 | <term><varname>Nice=</varname></term> | |
165 | ||
166 | <listitem><para>Sets the default nice level (scheduling | |
167 | priority) for executed processes. Takes an integer between -20 | |
168 | (highest priority) and 19 (lowest priority). See | |
169 | <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
170 | for details.</para></listitem> | |
171 | </varlistentry> | |
172 | ||
173 | <varlistentry> | |
174 | <term><varname>OOMScoreAdjust=</varname></term> | |
175 | ||
176 | <listitem><para>Sets the adjustment level for the | |
177 | Out-Of-Memory killer for executed processes. Takes an integer | |
178 | between -1000 (to disable OOM killing for this process) and | |
179 | 1000 (to make killing of this process under memory pressure | |
180 | very likely). See <ulink | |
181 | url="https://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink> | |
182 | for details.</para></listitem> | |
183 | </varlistentry> | |
184 | ||
185 | <varlistentry> | |
186 | <term><varname>IOSchedulingClass=</varname></term> | |
187 | ||
b938cb90 | 188 | <listitem><para>Sets the I/O scheduling class for executed |
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189 | processes. Takes an integer between 0 and 3 or one of the |
190 | strings <option>none</option>, <option>realtime</option>, | |
191 | <option>best-effort</option> or <option>idle</option>. See | |
192 | <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
193 | for details.</para></listitem> | |
194 | </varlistentry> | |
195 | ||
196 | <varlistentry> | |
197 | <term><varname>IOSchedulingPriority=</varname></term> | |
198 | ||
b938cb90 | 199 | <listitem><para>Sets the I/O scheduling priority for executed |
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200 | processes. Takes an integer between 0 (highest priority) and 7 |
201 | (lowest priority). The available priorities depend on the | |
b938cb90 | 202 | selected I/O scheduling class (see above). See |
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203 | <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry> |
204 | for details.</para></listitem> | |
205 | </varlistentry> | |
206 | ||
207 | <varlistentry> | |
208 | <term><varname>CPUSchedulingPolicy=</varname></term> | |
209 | ||
210 | <listitem><para>Sets the CPU scheduling policy for executed | |
211 | processes. Takes one of | |
212 | <option>other</option>, | |
213 | <option>batch</option>, | |
214 | <option>idle</option>, | |
215 | <option>fifo</option> or | |
216 | <option>rr</option>. See | |
217 | <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
218 | for details.</para></listitem> | |
219 | </varlistentry> | |
220 | ||
221 | <varlistentry> | |
222 | <term><varname>CPUSchedulingPriority=</varname></term> | |
223 | ||
224 | <listitem><para>Sets the CPU scheduling priority for executed | |
225 | processes. The available priority range depends on the | |
226 | selected CPU scheduling policy (see above). For real-time | |
227 | scheduling policies an integer between 1 (lowest priority) and | |
228 | 99 (highest priority) can be used. See | |
229 | <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
230 | for details. </para></listitem> | |
231 | </varlistentry> | |
232 | ||
233 | <varlistentry> | |
234 | <term><varname>CPUSchedulingResetOnFork=</varname></term> | |
235 | ||
236 | <listitem><para>Takes a boolean argument. If true, elevated | |
237 | CPU scheduling priorities and policies will be reset when the | |
238 | executed processes fork, and can hence not leak into child | |
239 | processes. See | |
240 | <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
241 | for details. Defaults to false.</para></listitem> | |
242 | </varlistentry> | |
243 | ||
244 | <varlistentry> | |
245 | <term><varname>CPUAffinity=</varname></term> | |
246 | ||
247 | <listitem><para>Controls the CPU affinity of the executed | |
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248 | processes. Takes a list of CPU indices or ranges separated by |
249 | either whitespace or commas. CPU ranges are specified by the | |
250 | lower and upper CPU indices separated by a dash. | |
b938cb90 | 251 | This option may be specified more than once, in which case the |
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252 | specified CPU affinity masks are merged. If the empty string |
253 | is assigned, the mask is reset, all assignments prior to this | |
254 | will have no effect. See | |
255 | <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
256 | for details.</para></listitem> | |
257 | </varlistentry> | |
258 | ||
259 | <varlistentry> | |
260 | <term><varname>UMask=</varname></term> | |
261 | ||
262 | <listitem><para>Controls the file mode creation mask. Takes an | |
263 | access mode in octal notation. See | |
264 | <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
265 | for details. Defaults to 0022.</para></listitem> | |
266 | </varlistentry> | |
267 | ||
268 | <varlistentry> | |
269 | <term><varname>Environment=</varname></term> | |
270 | ||
271 | <listitem><para>Sets environment variables for executed | |
272 | processes. Takes a space-separated list of variable | |
b938cb90 | 273 | assignments. This option may be specified more than once, in |
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274 | which case all listed variables will be set. If the same |
275 | variable is set twice, the later setting will override the | |
276 | earlier setting. If the empty string is assigned to this | |
277 | option, the list of environment variables is reset, all prior | |
278 | assignments have no effect. Variable expansion is not | |
279 | performed inside the strings, however, specifier expansion is | |
280 | possible. The $ character has no special meaning. If you need | |
281 | to assign a value containing spaces to a variable, use double | |
282 | quotes (") for the assignment.</para> | |
283 | ||
284 | <para>Example: | |
285 | <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"</programlisting> | |
286 | gives three variables <literal>VAR1</literal>, | |
287 | <literal>VAR2</literal>, <literal>VAR3</literal> | |
288 | with the values <literal>word1 word2</literal>, | |
289 | <literal>word3</literal>, <literal>$word 5 6</literal>. | |
290 | </para> | |
291 | ||
292 | <para> | |
293 | See | |
294 | <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
295 | for details about environment variables.</para></listitem> | |
296 | </varlistentry> | |
297 | <varlistentry> | |
298 | <term><varname>EnvironmentFile=</varname></term> | |
299 | <listitem><para>Similar to <varname>Environment=</varname> but | |
300 | reads the environment variables from a text file. The text | |
301 | file should contain new-line-separated variable assignments. | |
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302 | Empty lines, lines without an <literal>=</literal> separator, |
303 | or lines starting with ; or # will be ignored, | |
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304 | which may be used for commenting. A line ending with a |
305 | backslash will be concatenated with the following one, | |
306 | allowing multiline variable definitions. The parser strips | |
307 | leading and trailing whitespace from the values of | |
308 | assignments, unless you use double quotes (").</para> | |
309 | ||
310 | <para>The argument passed should be an absolute filename or | |
311 | wildcard expression, optionally prefixed with | |
312 | <literal>-</literal>, which indicates that if the file does | |
313 | not exist, it will not be read and no error or warning message | |
314 | is logged. This option may be specified more than once in | |
315 | which case all specified files are read. If the empty string | |
316 | is assigned to this option, the list of file to read is reset, | |
317 | all prior assignments have no effect.</para> | |
318 | ||
319 | <para>The files listed with this directive will be read | |
320 | shortly before the process is executed (more specifically, | |
321 | after all processes from a previous unit state terminated. | |
322 | This means you can generate these files in one unit state, and | |
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323 | read it with this option in the next).</para> |
324 | ||
325 | <para>Settings from these | |
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326 | files override settings made with |
327 | <varname>Environment=</varname>. If the same variable is set | |
328 | twice from these files, the files will be read in the order | |
329 | they are specified and the later setting will override the | |
330 | earlier setting.</para></listitem> | |
331 | </varlistentry> | |
332 | ||
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333 | <varlistentry> |
334 | <term><varname>PassEnvironment=</varname></term> | |
335 | ||
336 | <listitem><para>Pass environment variables from the systemd system | |
337 | manager to executed processes. Takes a space-separated list of variable | |
338 | names. This option may be specified more than once, in which case all | |
339 | listed variables will be set. If the empty string is assigned to this | |
340 | option, the list of environment variables is reset, all prior | |
341 | assignments have no effect. Variables that are not set in the system | |
342 | manager will not be passed and will be silently ignored.</para> | |
343 | ||
344 | <para>Variables passed from this setting are overridden by those passed | |
345 | from <varname>Environment=</varname> or | |
346 | <varname>EnvironmentFile=</varname>.</para> | |
347 | ||
348 | <para>Example: | |
349 | <programlisting>PassEnvironment=VAR1 VAR2 VAR3</programlisting> | |
350 | passes three variables <literal>VAR1</literal>, | |
351 | <literal>VAR2</literal>, <literal>VAR3</literal> | |
352 | with the values set for those variables in PID1.</para> | |
353 | ||
354 | <para> | |
355 | See | |
356 | <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
357 | for details about environment variables.</para></listitem> | |
358 | </varlistentry> | |
359 | ||
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360 | <varlistentry> |
361 | <term><varname>StandardInput=</varname></term> | |
362 | <listitem><para>Controls where file descriptor 0 (STDIN) of | |
363 | the executed processes is connected to. Takes one of | |
364 | <option>null</option>, | |
365 | <option>tty</option>, | |
366 | <option>tty-force</option>, | |
367 | <option>tty-fail</option> or | |
368 | <option>socket</option>.</para> | |
369 | ||
370 | <para>If <option>null</option> is selected, standard input | |
371 | will be connected to <filename>/dev/null</filename>, i.e. all | |
372 | read attempts by the process will result in immediate | |
373 | EOF.</para> | |
374 | ||
375 | <para>If <option>tty</option> is selected, standard input is | |
376 | connected to a TTY (as configured by | |
377 | <varname>TTYPath=</varname>, see below) and the executed | |
378 | process becomes the controlling process of the terminal. If | |
379 | the terminal is already being controlled by another process, | |
380 | the executed process waits until the current controlling | |
381 | process releases the terminal.</para> | |
382 | ||
383 | <para><option>tty-force</option> is similar to | |
384 | <option>tty</option>, but the executed process is forcefully | |
385 | and immediately made the controlling process of the terminal, | |
386 | potentially removing previous controlling processes from the | |
387 | terminal.</para> | |
388 | ||
389 | <para><option>tty-fail</option> is similar to | |
390 | <option>tty</option> but if the terminal already has a | |
391 | controlling process start-up of the executed process | |
392 | fails.</para> | |
393 | ||
394 | <para>The <option>socket</option> option is only valid in | |
395 | socket-activated services, and only when the socket | |
396 | configuration file (see | |
397 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
398 | for details) specifies a single socket only. If this option is | |
399 | set, standard input will be connected to the socket the | |
400 | service was activated from, which is primarily useful for | |
401 | compatibility with daemons designed for use with the | |
402 | traditional | |
b5c7d097 | 403 | <citerefentry project='freebsd'><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
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404 | daemon.</para> |
405 | ||
406 | <para>This setting defaults to | |
407 | <option>null</option>.</para></listitem> | |
408 | </varlistentry> | |
c129bd5d | 409 | |
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410 | <varlistentry> |
411 | <term><varname>StandardOutput=</varname></term> | |
412 | <listitem><para>Controls where file descriptor 1 (STDOUT) of | |
413 | the executed processes is connected to. Takes one of | |
414 | <option>inherit</option>, | |
415 | <option>null</option>, | |
416 | <option>tty</option>, | |
417 | <option>journal</option>, | |
418 | <option>syslog</option>, | |
419 | <option>kmsg</option>, | |
420 | <option>journal+console</option>, | |
421 | <option>syslog+console</option>, | |
422 | <option>kmsg+console</option> or | |
423 | <option>socket</option>.</para> | |
424 | ||
425 | <para><option>inherit</option> duplicates the file descriptor | |
426 | of standard input for standard output.</para> | |
427 | ||
428 | <para><option>null</option> connects standard output to | |
429 | <filename>/dev/null</filename>, i.e. everything written to it | |
430 | will be lost.</para> | |
431 | ||
432 | <para><option>tty</option> connects standard output to a tty | |
433 | (as configured via <varname>TTYPath=</varname>, see below). If | |
434 | the TTY is used for output only, the executed process will not | |
435 | become the controlling process of the terminal, and will not | |
436 | fail or wait for other processes to release the | |
437 | terminal.</para> | |
438 | ||
439 | <para><option>journal</option> connects standard output with | |
440 | the journal which is accessible via | |
441 | <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. | |
442 | Note that everything that is written to syslog or kmsg (see | |
443 | below) is implicitly stored in the journal as well, the | |
444 | specific two options listed below are hence supersets of this | |
445 | one.</para> | |
446 | ||
447 | <para><option>syslog</option> connects standard output to the | |
448 | <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
449 | system syslog service, in addition to the journal. Note that | |
450 | the journal daemon is usually configured to forward everything | |
451 | it receives to syslog anyway, in which case this option is no | |
452 | different from <option>journal</option>.</para> | |
453 | ||
454 | <para><option>kmsg</option> connects standard output with the | |
455 | kernel log buffer which is accessible via | |
456 | <citerefentry project='man-pages'><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
457 | in addition to the journal. The journal daemon might be | |
458 | configured to send all logs to kmsg anyway, in which case this | |
459 | option is no different from <option>journal</option>.</para> | |
460 | ||
461 | <para><option>journal+console</option>, | |
462 | <option>syslog+console</option> and | |
463 | <option>kmsg+console</option> work in a similar way as the | |
464 | three options above but copy the output to the system console | |
465 | as well.</para> | |
466 | ||
467 | <para><option>socket</option> connects standard output to a | |
468 | socket acquired via socket activation. The semantics are | |
469 | similar to the same option of | |
470 | <varname>StandardInput=</varname>.</para> | |
471 | ||
28c75e25 LP |
472 | <para>If the standard output (or error output, see below) of a unit is connected with the journal, syslog or |
473 | the kernel log buffer the unit will implicitly gain a dependency of type <varname>After=</varname> on | |
474 | <filename>systemd-journald.socket</filename> (also see the automatic dependencies section above).</para> | |
475 | ||
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476 | <para>This setting defaults to the value set with |
477 | <option>DefaultStandardOutput=</option> in | |
478 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
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479 | which defaults to <option>journal</option>. Note that setting |
480 | this parameter might result in additional dependencies to be | |
481 | added to the unit (see above).</para></listitem> | |
798d3a52 | 482 | </varlistentry> |
c129bd5d | 483 | |
798d3a52 ZJS |
484 | <varlistentry> |
485 | <term><varname>StandardError=</varname></term> | |
486 | <listitem><para>Controls where file descriptor 2 (STDERR) of | |
487 | the executed processes is connected to. The available options | |
488 | are identical to those of <varname>StandardOutput=</varname>, | |
489 | with one exception: if set to <option>inherit</option> the | |
490 | file descriptor used for standard output is duplicated for | |
491 | standard error. This setting defaults to the value set with | |
492 | <option>DefaultStandardError=</option> in | |
493 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
c129bd5d LP |
494 | which defaults to <option>inherit</option>. Note that setting |
495 | this parameter might result in additional dependencies to be | |
496 | added to the unit (see above).</para></listitem> | |
798d3a52 | 497 | </varlistentry> |
c129bd5d | 498 | |
798d3a52 ZJS |
499 | <varlistentry> |
500 | <term><varname>TTYPath=</varname></term> | |
501 | <listitem><para>Sets the terminal device node to use if | |
502 | standard input, output, or error are connected to a TTY (see | |
503 | above). Defaults to | |
504 | <filename>/dev/console</filename>.</para></listitem> | |
505 | </varlistentry> | |
506 | <varlistentry> | |
507 | <term><varname>TTYReset=</varname></term> | |
508 | <listitem><para>Reset the terminal device specified with | |
509 | <varname>TTYPath=</varname> before and after execution. | |
510 | Defaults to <literal>no</literal>.</para></listitem> | |
511 | </varlistentry> | |
512 | <varlistentry> | |
513 | <term><varname>TTYVHangup=</varname></term> | |
514 | <listitem><para>Disconnect all clients which have opened the | |
515 | terminal device specified with <varname>TTYPath=</varname> | |
516 | before and after execution. Defaults to | |
517 | <literal>no</literal>.</para></listitem> | |
518 | </varlistentry> | |
519 | <varlistentry> | |
520 | <term><varname>TTYVTDisallocate=</varname></term> | |
521 | <listitem><para>If the terminal device specified with | |
522 | <varname>TTYPath=</varname> is a virtual console terminal, try | |
523 | to deallocate the TTY before and after execution. This ensures | |
524 | that the screen and scrollback buffer is cleared. Defaults to | |
525 | <literal>no</literal>.</para></listitem> | |
526 | </varlistentry> | |
527 | <varlistentry> | |
528 | <term><varname>SyslogIdentifier=</varname></term> | |
529 | <listitem><para>Sets the process name to prefix log lines sent | |
530 | to the logging system or the kernel log buffer with. If not | |
531 | set, defaults to the process name of the executed process. | |
532 | This option is only useful when | |
533 | <varname>StandardOutput=</varname> or | |
534 | <varname>StandardError=</varname> are set to | |
535 | <option>syslog</option>, <option>journal</option> or | |
536 | <option>kmsg</option> (or to the same settings in combination | |
537 | with <option>+console</option>).</para></listitem> | |
538 | </varlistentry> | |
539 | <varlistentry> | |
540 | <term><varname>SyslogFacility=</varname></term> | |
541 | <listitem><para>Sets the syslog facility to use when logging | |
542 | to syslog. One of <option>kern</option>, | |
543 | <option>user</option>, <option>mail</option>, | |
544 | <option>daemon</option>, <option>auth</option>, | |
545 | <option>syslog</option>, <option>lpr</option>, | |
546 | <option>news</option>, <option>uucp</option>, | |
547 | <option>cron</option>, <option>authpriv</option>, | |
548 | <option>ftp</option>, <option>local0</option>, | |
549 | <option>local1</option>, <option>local2</option>, | |
550 | <option>local3</option>, <option>local4</option>, | |
551 | <option>local5</option>, <option>local6</option> or | |
552 | <option>local7</option>. See | |
553 | <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
554 | for details. This option is only useful when | |
555 | <varname>StandardOutput=</varname> or | |
556 | <varname>StandardError=</varname> are set to | |
557 | <option>syslog</option>. Defaults to | |
558 | <option>daemon</option>.</para></listitem> | |
559 | </varlistentry> | |
560 | <varlistentry> | |
561 | <term><varname>SyslogLevel=</varname></term> | |
a8eaaee7 | 562 | <listitem><para>The default syslog level to use when logging to |
798d3a52 ZJS |
563 | syslog or the kernel log buffer. One of |
564 | <option>emerg</option>, | |
565 | <option>alert</option>, | |
566 | <option>crit</option>, | |
567 | <option>err</option>, | |
568 | <option>warning</option>, | |
569 | <option>notice</option>, | |
570 | <option>info</option>, | |
571 | <option>debug</option>. See | |
572 | <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
573 | for details. This option is only useful when | |
574 | <varname>StandardOutput=</varname> or | |
575 | <varname>StandardError=</varname> are set to | |
576 | <option>syslog</option> or <option>kmsg</option>. Note that | |
577 | individual lines output by the daemon might be prefixed with a | |
578 | different log level which can be used to override the default | |
579 | log level specified here. The interpretation of these prefixes | |
580 | may be disabled with <varname>SyslogLevelPrefix=</varname>, | |
b938cb90 | 581 | see below. For details, see |
798d3a52 ZJS |
582 | <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>. |
583 | ||
584 | Defaults to | |
585 | <option>info</option>.</para></listitem> | |
586 | </varlistentry> | |
587 | ||
588 | <varlistentry> | |
589 | <term><varname>SyslogLevelPrefix=</varname></term> | |
590 | <listitem><para>Takes a boolean argument. If true and | |
591 | <varname>StandardOutput=</varname> or | |
592 | <varname>StandardError=</varname> are set to | |
593 | <option>syslog</option>, <option>kmsg</option> or | |
594 | <option>journal</option>, log lines written by the executed | |
595 | process that are prefixed with a log level will be passed on | |
596 | to syslog with this log level set but the prefix removed. If | |
597 | set to false, the interpretation of these prefixes is disabled | |
598 | and the logged lines are passed on as-is. For details about | |
599 | this prefixing see | |
600 | <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
601 | Defaults to true.</para></listitem> | |
602 | </varlistentry> | |
603 | ||
604 | <varlistentry> | |
605 | <term><varname>TimerSlackNSec=</varname></term> | |
606 | <listitem><para>Sets the timer slack in nanoseconds for the | |
607 | executed processes. The timer slack controls the accuracy of | |
608 | wake-ups triggered by timers. See | |
609 | <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
610 | for more information. Note that in contrast to most other time | |
611 | span definitions this parameter takes an integer value in | |
612 | nano-seconds if no unit is specified. The usual time units are | |
613 | understood too.</para></listitem> | |
614 | </varlistentry> | |
615 | ||
616 | <varlistentry> | |
617 | <term><varname>LimitCPU=</varname></term> | |
618 | <term><varname>LimitFSIZE=</varname></term> | |
619 | <term><varname>LimitDATA=</varname></term> | |
620 | <term><varname>LimitSTACK=</varname></term> | |
621 | <term><varname>LimitCORE=</varname></term> | |
622 | <term><varname>LimitRSS=</varname></term> | |
623 | <term><varname>LimitNOFILE=</varname></term> | |
624 | <term><varname>LimitAS=</varname></term> | |
625 | <term><varname>LimitNPROC=</varname></term> | |
626 | <term><varname>LimitMEMLOCK=</varname></term> | |
627 | <term><varname>LimitLOCKS=</varname></term> | |
628 | <term><varname>LimitSIGPENDING=</varname></term> | |
629 | <term><varname>LimitMSGQUEUE=</varname></term> | |
630 | <term><varname>LimitNICE=</varname></term> | |
631 | <term><varname>LimitRTPRIO=</varname></term> | |
632 | <term><varname>LimitRTTIME=</varname></term> | |
633 | <listitem><para>These settings set both soft and hard limits | |
634 | of various resources for executed processes. See | |
635 | <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
91518d20 KZ |
636 | for details. The resource limit is possible to specify in two formats, |
637 | <option>value</option> to set soft and hard limits to the same value, | |
638 | or <option>soft:hard</option> to set both limits individually (e.g. LimitAS=4G:16G). | |
639 | Use the string <varname>infinity</varname> to | |
a4c18002 LP |
640 | configure no limit on a specific resource. The multiplicative |
641 | suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E | |
642 | may be used for resource limits measured in bytes | |
643 | (e.g. LimitAS=16G). For the limits referring to time values, | |
644 | the usual time units ms, s, min, h and so on may be used (see | |
645 | <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
646 | for details). Note that if no time unit is specified for | |
647 | <varname>LimitCPU=</varname> the default unit of seconds is | |
648 | implied, while for <varname>LimitRTTIME=</varname> the default | |
649 | unit of microseconds is implied. Also, note that the effective | |
650 | granularity of the limits might influence their | |
651 | enforcement. For example, time limits specified for | |
652 | <varname>LimitCPU=</varname> will be rounded up implicitly to | |
653 | multiples of 1s.</para> | |
654 | ||
655 | <para>Note that most process resource limits configured with | |
656 | these options are per-process, and processes may fork in order | |
657 | to acquire a new set of resources that are accounted | |
658 | independently of the original process, and may thus escape | |
659 | limits set. Also note that <varname>LimitRSS=</varname> is not | |
660 | implemented on Linux, and setting it has no effect. Often it | |
661 | is advisable to prefer the resource controls listed in | |
662 | <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
663 | over these per-process limits, as they apply to services as a | |
664 | whole, may be altered dynamically at runtime, and are | |
665 | generally more expressive. For example, | |
666 | <varname>MemoryLimit=</varname> is a more powerful (and | |
667 | working) replacement for <varname>LimitRSS=</varname>.</para> | |
798d3a52 ZJS |
668 | |
669 | <table> | |
670 | <title>Limit directives and their equivalent with ulimit</title> | |
671 | ||
a4c18002 | 672 | <tgroup cols='3'> |
798d3a52 ZJS |
673 | <colspec colname='directive' /> |
674 | <colspec colname='equivalent' /> | |
a4c18002 | 675 | <colspec colname='unit' /> |
798d3a52 ZJS |
676 | <thead> |
677 | <row> | |
678 | <entry>Directive</entry> | |
679 | <entry>ulimit equivalent</entry> | |
a4c18002 | 680 | <entry>Unit</entry> |
798d3a52 ZJS |
681 | </row> |
682 | </thead> | |
683 | <tbody> | |
684 | <row> | |
a4c18002 | 685 | <entry>LimitCPU=</entry> |
798d3a52 | 686 | <entry>ulimit -t</entry> |
a4c18002 | 687 | <entry>Seconds</entry> |
798d3a52 ZJS |
688 | </row> |
689 | <row> | |
a4c18002 | 690 | <entry>LimitFSIZE=</entry> |
798d3a52 | 691 | <entry>ulimit -f</entry> |
a4c18002 | 692 | <entry>Bytes</entry> |
798d3a52 ZJS |
693 | </row> |
694 | <row> | |
a4c18002 | 695 | <entry>LimitDATA=</entry> |
798d3a52 | 696 | <entry>ulimit -d</entry> |
a4c18002 | 697 | <entry>Bytes</entry> |
798d3a52 ZJS |
698 | </row> |
699 | <row> | |
a4c18002 | 700 | <entry>LimitSTACK=</entry> |
798d3a52 | 701 | <entry>ulimit -s</entry> |
a4c18002 | 702 | <entry>Bytes</entry> |
798d3a52 ZJS |
703 | </row> |
704 | <row> | |
a4c18002 | 705 | <entry>LimitCORE=</entry> |
798d3a52 | 706 | <entry>ulimit -c</entry> |
a4c18002 | 707 | <entry>Bytes</entry> |
798d3a52 ZJS |
708 | </row> |
709 | <row> | |
a4c18002 | 710 | <entry>LimitRSS=</entry> |
798d3a52 | 711 | <entry>ulimit -m</entry> |
a4c18002 | 712 | <entry>Bytes</entry> |
798d3a52 ZJS |
713 | </row> |
714 | <row> | |
a4c18002 | 715 | <entry>LimitNOFILE=</entry> |
798d3a52 | 716 | <entry>ulimit -n</entry> |
a4c18002 | 717 | <entry>Number of File Descriptors</entry> |
798d3a52 ZJS |
718 | </row> |
719 | <row> | |
a4c18002 | 720 | <entry>LimitAS=</entry> |
798d3a52 | 721 | <entry>ulimit -v</entry> |
a4c18002 | 722 | <entry>Bytes</entry> |
798d3a52 ZJS |
723 | </row> |
724 | <row> | |
a4c18002 | 725 | <entry>LimitNPROC=</entry> |
798d3a52 | 726 | <entry>ulimit -u</entry> |
a4c18002 | 727 | <entry>Number of Processes</entry> |
798d3a52 ZJS |
728 | </row> |
729 | <row> | |
a4c18002 | 730 | <entry>LimitMEMLOCK=</entry> |
798d3a52 | 731 | <entry>ulimit -l</entry> |
a4c18002 | 732 | <entry>Bytes</entry> |
798d3a52 ZJS |
733 | </row> |
734 | <row> | |
a4c18002 | 735 | <entry>LimitLOCKS=</entry> |
798d3a52 | 736 | <entry>ulimit -x</entry> |
a4c18002 | 737 | <entry>Number of Locks</entry> |
798d3a52 ZJS |
738 | </row> |
739 | <row> | |
a4c18002 | 740 | <entry>LimitSIGPENDING=</entry> |
798d3a52 | 741 | <entry>ulimit -i</entry> |
a4c18002 | 742 | <entry>Number of Queued Signals</entry> |
798d3a52 ZJS |
743 | </row> |
744 | <row> | |
a4c18002 | 745 | <entry>LimitMSGQUEUE=</entry> |
798d3a52 | 746 | <entry>ulimit -q</entry> |
a4c18002 | 747 | <entry>Bytes</entry> |
798d3a52 ZJS |
748 | </row> |
749 | <row> | |
a4c18002 | 750 | <entry>LimitNICE=</entry> |
798d3a52 | 751 | <entry>ulimit -e</entry> |
a4c18002 | 752 | <entry>Nice Level</entry> |
798d3a52 ZJS |
753 | </row> |
754 | <row> | |
a4c18002 | 755 | <entry>LimitRTPRIO=</entry> |
798d3a52 | 756 | <entry>ulimit -r</entry> |
a4c18002 | 757 | <entry>Realtime Priority</entry> |
798d3a52 ZJS |
758 | </row> |
759 | <row> | |
a4c18002 | 760 | <entry>LimitRTTIME=</entry> |
798d3a52 | 761 | <entry>No equivalent</entry> |
a4c18002 | 762 | <entry>Microseconds</entry> |
798d3a52 ZJS |
763 | </row> |
764 | </tbody> | |
765 | </tgroup> | |
a4c18002 | 766 | </table></listitem> |
798d3a52 ZJS |
767 | </varlistentry> |
768 | ||
769 | <varlistentry> | |
770 | <term><varname>PAMName=</varname></term> | |
771 | <listitem><para>Sets the PAM service name to set up a session | |
772 | as. If set, the executed process will be registered as a PAM | |
773 | session under the specified service name. This is only useful | |
774 | in conjunction with the <varname>User=</varname> setting. If | |
775 | not set, no PAM session will be opened for the executed | |
776 | processes. See | |
777 | <citerefentry project='man-pages'><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
778 | for details.</para></listitem> | |
779 | </varlistentry> | |
780 | ||
781 | <varlistentry> | |
782 | <term><varname>CapabilityBoundingSet=</varname></term> | |
783 | ||
479050b3 LP |
784 | <listitem><para>Controls which capabilities to include in the capability bounding set for the executed |
785 | process. See <citerefentry | |
786 | project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> for | |
787 | details. Takes a whitespace-separated list of capability names as read by <citerefentry | |
788 | project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
789 | e.g. <constant>CAP_SYS_ADMIN</constant>, <constant>CAP_DAC_OVERRIDE</constant>, | |
790 | <constant>CAP_SYS_PTRACE</constant>. Capabilities listed will be included in the bounding set, all others are | |
791 | removed. If the list of capabilities is prefixed with <literal>~</literal>, all but the listed capabilities | |
792 | will be included, the effect of the assignment inverted. Note that this option also affects the respective | |
793 | capabilities in the effective, permitted and inheritable capability sets. If this option is not used, the | |
794 | capability bounding set is not modified on process execution, hence no limits on the capabilities of the | |
795 | process are enforced. This option may appear more than once, in which case the bounding sets are merged. If the | |
796 | empty string is assigned to this option, the bounding set is reset to the empty capability set, and all prior | |
797 | settings have no effect. If set to <literal>~</literal> (without any further argument), the bounding set is | |
798 | reset to the full set of available capabilities, also undoing any previous settings.</para></listitem> | |
798d3a52 ZJS |
799 | </varlistentry> |
800 | ||
ece87975 IP |
801 | <varlistentry> |
802 | <term><varname>AmbientCapabilities=</varname></term> | |
803 | ||
804 | <listitem><para>Controls which capabilities to include in the | |
805 | ambient capability set for the executed process. Takes a | |
806 | whitespace-separated list of capability names as read by | |
807 | <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
808 | e.g. <constant>CAP_SYS_ADMIN</constant>, | |
809 | <constant>CAP_DAC_OVERRIDE</constant>, | |
810 | <constant>CAP_SYS_PTRACE</constant>. This option may appear more than | |
811 | once in which case the ambient capability sets are merged. | |
812 | If the list of capabilities is prefixed with <literal>~</literal>, all | |
813 | but the listed capabilities will be included, the effect of the | |
814 | assignment inverted. If the empty string is | |
815 | assigned to this option, the ambient capability set is reset to | |
816 | the empty capability set, and all prior settings have no effect. | |
817 | If set to <literal>~</literal> (without any further argument), the | |
818 | ambient capability set is reset to the full set of available | |
819 | capabilities, also undoing any previous settings. Note that adding | |
820 | capabilities to ambient capability set adds them to the process's | |
821 | inherited capability set. | |
822 | </para><para> | |
823 | Ambient capability sets are useful if you want to execute a process | |
824 | as a non-privileged user but still want to give it some capabilities. | |
825 | Note that in this case option <constant>keep-caps</constant> is | |
826 | automatically added to <varname>SecureBits=</varname> to retain the | |
827 | capabilities over the user change.</para></listitem> | |
828 | </varlistentry> | |
829 | ||
798d3a52 ZJS |
830 | <varlistentry> |
831 | <term><varname>SecureBits=</varname></term> | |
832 | <listitem><para>Controls the secure bits set for the executed | |
833 | process. Takes a space-separated combination of options from | |
834 | the following list: | |
835 | <option>keep-caps</option>, | |
836 | <option>keep-caps-locked</option>, | |
837 | <option>no-setuid-fixup</option>, | |
838 | <option>no-setuid-fixup-locked</option>, | |
839 | <option>noroot</option>, and | |
840 | <option>noroot-locked</option>. | |
b938cb90 | 841 | This option may appear more than once, in which case the secure |
798d3a52 ZJS |
842 | bits are ORed. If the empty string is assigned to this option, |
843 | the bits are reset to 0. See | |
844 | <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
845 | for details.</para></listitem> | |
846 | </varlistentry> | |
847 | ||
798d3a52 ZJS |
848 | <varlistentry> |
849 | <term><varname>ReadWriteDirectories=</varname></term> | |
850 | <term><varname>ReadOnlyDirectories=</varname></term> | |
851 | <term><varname>InaccessibleDirectories=</varname></term> | |
852 | ||
853 | <listitem><para>Sets up a new file system namespace for | |
854 | executed processes. These options may be used to limit access | |
855 | a process might have to the main file system hierarchy. Each | |
856 | setting takes a space-separated list of absolute directory | |
857 | paths. Directories listed in | |
858 | <varname>ReadWriteDirectories=</varname> are accessible from | |
859 | within the namespace with the same access rights as from | |
860 | outside. Directories listed in | |
861 | <varname>ReadOnlyDirectories=</varname> are accessible for | |
862 | reading only, writing will be refused even if the usual file | |
863 | access controls would permit this. Directories listed in | |
864 | <varname>InaccessibleDirectories=</varname> will be made | |
b50a16af NBS |
865 | inaccessible for processes inside the namespace, and may not |
866 | countain any other mountpoints, including those specified by | |
867 | <varname>ReadWriteDirectories=</varname> or | |
868 | <varname>ReadOnlyDirectories=</varname>. | |
869 | Note that restricting access with these options does not extend | |
870 | to submounts of a directory that are created later on. These | |
b938cb90 | 871 | options may be specified more than once, in which case all |
798d3a52 ZJS |
872 | directories listed will have limited access from within the |
873 | namespace. If the empty string is assigned to this option, the | |
874 | specific list is reset, and all prior assignments have no | |
875 | effect.</para> | |
876 | <para>Paths in | |
877 | <varname>ReadOnlyDirectories=</varname> | |
878 | and | |
879 | <varname>InaccessibleDirectories=</varname> | |
880 | may be prefixed with | |
881 | <literal>-</literal>, in which case | |
882 | they will be ignored when they do not | |
883 | exist. Note that using this | |
884 | setting will disconnect propagation of | |
885 | mounts from the service to the host | |
886 | (propagation in the opposite direction | |
887 | continues to work). This means that | |
888 | this setting may not be used for | |
889 | services which shall be able to | |
890 | install mount points in the main mount | |
891 | namespace.</para></listitem> | |
892 | </varlistentry> | |
893 | ||
894 | <varlistentry> | |
895 | <term><varname>PrivateTmp=</varname></term> | |
896 | ||
897 | <listitem><para>Takes a boolean argument. If true, sets up a | |
898 | new file system namespace for the executed processes and | |
899 | mounts private <filename>/tmp</filename> and | |
900 | <filename>/var/tmp</filename> directories inside it that is | |
901 | not shared by processes outside of the namespace. This is | |
902 | useful to secure access to temporary files of the process, but | |
903 | makes sharing between processes via <filename>/tmp</filename> | |
904 | or <filename>/var/tmp</filename> impossible. If this is | |
905 | enabled, all temporary files created by a service in these | |
906 | directories will be removed after the service is stopped. | |
907 | Defaults to false. It is possible to run two or more units | |
908 | within the same private <filename>/tmp</filename> and | |
909 | <filename>/var/tmp</filename> namespace by using the | |
910 | <varname>JoinsNamespaceOf=</varname> directive, see | |
911 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
912 | for details. Note that using this setting will disconnect | |
913 | propagation of mounts from the service to the host | |
914 | (propagation in the opposite direction continues to work). | |
915 | This means that this setting may not be used for services | |
916 | which shall be able to install mount points in the main mount | |
917 | namespace.</para></listitem> | |
918 | </varlistentry> | |
919 | ||
920 | <varlistentry> | |
921 | <term><varname>PrivateDevices=</varname></term> | |
922 | ||
923 | <listitem><para>Takes a boolean argument. If true, sets up a | |
924 | new /dev namespace for the executed processes and only adds | |
925 | API pseudo devices such as <filename>/dev/null</filename>, | |
926 | <filename>/dev/zero</filename> or | |
927 | <filename>/dev/random</filename> (as well as the pseudo TTY | |
928 | subsystem) to it, but no physical devices such as | |
929 | <filename>/dev/sda</filename>. This is useful to securely turn | |
930 | off physical device access by the executed process. Defaults | |
931 | to false. Enabling this option will also remove | |
932 | <constant>CAP_MKNOD</constant> from the capability bounding | |
933 | set for the unit (see above), and set | |
934 | <varname>DevicePolicy=closed</varname> (see | |
935 | <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
936 | for details). Note that using this setting will disconnect | |
937 | propagation of mounts from the service to the host | |
938 | (propagation in the opposite direction continues to work). | |
939 | This means that this setting may not be used for services | |
940 | which shall be able to install mount points in the main mount | |
941 | namespace.</para></listitem> | |
942 | </varlistentry> | |
943 | ||
944 | <varlistentry> | |
945 | <term><varname>PrivateNetwork=</varname></term> | |
946 | ||
947 | <listitem><para>Takes a boolean argument. If true, sets up a | |
948 | new network namespace for the executed processes and | |
949 | configures only the loopback network device | |
950 | <literal>lo</literal> inside it. No other network devices will | |
951 | be available to the executed process. This is useful to | |
952 | securely turn off network access by the executed process. | |
953 | Defaults to false. It is possible to run two or more units | |
954 | within the same private network namespace by using the | |
955 | <varname>JoinsNamespaceOf=</varname> directive, see | |
956 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
957 | for details. Note that this option will disconnect all socket | |
958 | families from the host, this includes AF_NETLINK and AF_UNIX. | |
959 | The latter has the effect that AF_UNIX sockets in the abstract | |
960 | socket namespace will become unavailable to the processes | |
961 | (however, those located in the file system will continue to be | |
962 | accessible).</para></listitem> | |
963 | </varlistentry> | |
964 | ||
965 | <varlistentry> | |
966 | <term><varname>ProtectSystem=</varname></term> | |
967 | ||
968 | <listitem><para>Takes a boolean argument or | |
969 | <literal>full</literal>. If true, mounts the | |
970 | <filename>/usr</filename> and <filename>/boot</filename> | |
971 | directories read-only for processes invoked by this unit. If | |
972 | set to <literal>full</literal>, the <filename>/etc</filename> | |
973 | directory is mounted read-only, too. This setting ensures that | |
b938cb90 | 974 | any modification of the vendor-supplied operating system (and |
798d3a52 ZJS |
975 | optionally its configuration) is prohibited for the service. |
976 | It is recommended to enable this setting for all long-running | |
977 | services, unless they are involved with system updates or need | |
978 | to modify the operating system in other ways. Note however | |
979 | that processes retaining the CAP_SYS_ADMIN capability can undo | |
980 | the effect of this setting. This setting is hence particularly | |
981 | useful for daemons which have this capability removed, for | |
982 | example with <varname>CapabilityBoundingSet=</varname>. | |
983 | Defaults to off.</para></listitem> | |
984 | </varlistentry> | |
985 | ||
986 | <varlistentry> | |
987 | <term><varname>ProtectHome=</varname></term> | |
988 | ||
989 | <listitem><para>Takes a boolean argument or | |
990 | <literal>read-only</literal>. If true, the directories | |
58331437 CH |
991 | <filename>/home</filename>, <filename>/root</filename> and |
992 | <filename>/run/user</filename> | |
798d3a52 | 993 | are made inaccessible and empty for processes invoked by this |
58331437 | 994 | unit. If set to <literal>read-only</literal>, the three |
798d3a52 ZJS |
995 | directories are made read-only instead. It is recommended to |
996 | enable this setting for all long-running services (in | |
997 | particular network-facing ones), to ensure they cannot get | |
998 | access to private user data, unless the services actually | |
999 | require access to the user's private data. Note however that | |
1000 | processes retaining the CAP_SYS_ADMIN capability can undo the | |
1001 | effect of this setting. This setting is hence particularly | |
1002 | useful for daemons which have this capability removed, for | |
1003 | example with <varname>CapabilityBoundingSet=</varname>. | |
1004 | Defaults to off.</para></listitem> | |
1005 | </varlistentry> | |
1006 | ||
1007 | <varlistentry> | |
1008 | <term><varname>MountFlags=</varname></term> | |
1009 | ||
1010 | <listitem><para>Takes a mount propagation flag: | |
1011 | <option>shared</option>, <option>slave</option> or | |
1012 | <option>private</option>, which control whether mounts in the | |
1013 | file system namespace set up for this unit's processes will | |
1014 | receive or propagate mounts or unmounts. See | |
3ba3a79d | 1015 | <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry> |
798d3a52 ZJS |
1016 | for details. Defaults to <option>shared</option>. Use |
1017 | <option>shared</option> to ensure that mounts and unmounts are | |
1018 | propagated from the host to the container and vice versa. Use | |
1019 | <option>slave</option> to run processes so that none of their | |
1020 | mounts and unmounts will propagate to the host. Use | |
1021 | <option>private</option> to also ensure that no mounts and | |
1022 | unmounts from the host will propagate into the unit processes' | |
1023 | namespace. Note that <option>slave</option> means that file | |
1024 | systems mounted on the host might stay mounted continuously in | |
1025 | the unit's namespace, and thus keep the device busy. Note that | |
1026 | the file system namespace related options | |
1027 | (<varname>PrivateTmp=</varname>, | |
1028 | <varname>PrivateDevices=</varname>, | |
1029 | <varname>ProtectSystem=</varname>, | |
1030 | <varname>ProtectHome=</varname>, | |
1031 | <varname>ReadOnlyDirectories=</varname>, | |
1032 | <varname>InaccessibleDirectories=</varname> and | |
1033 | <varname>ReadWriteDirectories=</varname>) require that mount | |
1034 | and unmount propagation from the unit's file system namespace | |
1035 | is disabled, and hence downgrade <option>shared</option> to | |
1036 | <option>slave</option>. </para></listitem> | |
1037 | </varlistentry> | |
1038 | ||
1039 | <varlistentry> | |
1040 | <term><varname>UtmpIdentifier=</varname></term> | |
1041 | ||
1042 | <listitem><para>Takes a four character identifier string for | |
023a4f67 LP |
1043 | an <citerefentry |
1044 | project='man-pages'><refentrytitle>utmp</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
1045 | and wtmp entry for this service. This should only be | |
1046 | set for services such as <command>getty</command> | |
1047 | implementations (such as <citerefentry | |
1048 | project='die-net'><refentrytitle>agetty</refentrytitle><manvolnum>8</manvolnum></citerefentry>) | |
798d3a52 | 1049 | where utmp/wtmp entries must be created and cleared before and |
023a4f67 LP |
1050 | after execution, or for services that shall be executed as if |
1051 | they were run by a <command>getty</command> process (see | |
1052 | below). If the configured string is longer than four | |
798d3a52 ZJS |
1053 | characters, it is truncated and the terminal four characters |
1054 | are used. This setting interprets %I style string | |
1055 | replacements. This setting is unset by default, i.e. no | |
1056 | utmp/wtmp entries are created or cleaned up for this | |
1057 | service.</para></listitem> | |
1058 | </varlistentry> | |
1059 | ||
023a4f67 LP |
1060 | <varlistentry> |
1061 | <term><varname>UtmpMode=</varname></term> | |
1062 | ||
1063 | <listitem><para>Takes one of <literal>init</literal>, | |
1064 | <literal>login</literal> or <literal>user</literal>. If | |
1065 | <varname>UtmpIdentifier=</varname> is set, controls which | |
1066 | type of <citerefentry | |
1067 | project='man-pages'><refentrytitle>utmp</refentrytitle><manvolnum>5</manvolnum></citerefentry>/wtmp | |
1068 | entries for this service are generated. This setting has no | |
1069 | effect unless <varname>UtmpIdentifier=</varname> is set | |
1070 | too. If <literal>init</literal> is set, only an | |
1071 | <constant>INIT_PROCESS</constant> entry is generated and the | |
6cd16034 LP |
1072 | invoked process must implement a |
1073 | <command>getty</command>-compatible utmp/wtmp logic. If | |
1074 | <literal>login</literal> is set, first an | |
a8eaaee7 | 1075 | <constant>INIT_PROCESS</constant> entry, followed by a |
6cd16034 | 1076 | <constant>LOGIN_PROCESS</constant> entry is generated. In |
b938cb90 | 1077 | this case, the invoked process must implement a <citerefentry |
023a4f67 LP |
1078 | project='die-net'><refentrytitle>login</refentrytitle><manvolnum>1</manvolnum></citerefentry>-compatible |
1079 | utmp/wtmp logic. If <literal>user</literal> is set, first an | |
1080 | <constant>INIT_PROCESS</constant> entry, then a | |
a8eaaee7 | 1081 | <constant>LOGIN_PROCESS</constant> entry and finally a |
023a4f67 | 1082 | <constant>USER_PROCESS</constant> entry is generated. In this |
b938cb90 | 1083 | case, the invoked process may be any process that is suitable |
023a4f67 LP |
1084 | to be run as session leader. Defaults to |
1085 | <literal>init</literal>.</para></listitem> | |
1086 | </varlistentry> | |
1087 | ||
798d3a52 ZJS |
1088 | <varlistentry> |
1089 | <term><varname>SELinuxContext=</varname></term> | |
1090 | ||
1091 | <listitem><para>Set the SELinux security context of the | |
1092 | executed process. If set, this will override the automated | |
1093 | domain transition. However, the policy still needs to | |
1094 | authorize the transition. This directive is ignored if SELinux | |
1095 | is disabled. If prefixed by <literal>-</literal>, all errors | |
1096 | will be ignored. See | |
3ba3a79d | 1097 | <citerefentry project='die-net'><refentrytitle>setexeccon</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
798d3a52 ZJS |
1098 | for details.</para></listitem> |
1099 | </varlistentry> | |
1100 | ||
1101 | <varlistentry> | |
1102 | <term><varname>AppArmorProfile=</varname></term> | |
1103 | ||
1104 | <listitem><para>Takes a profile name as argument. The process | |
1105 | executed by the unit will switch to this profile when started. | |
1106 | Profiles must already be loaded in the kernel, or the unit | |
1107 | will fail. This result in a non operation if AppArmor is not | |
1108 | enabled. If prefixed by <literal>-</literal>, all errors will | |
1109 | be ignored. </para></listitem> | |
1110 | </varlistentry> | |
1111 | ||
1112 | <varlistentry> | |
1113 | <term><varname>SmackProcessLabel=</varname></term> | |
1114 | ||
1115 | <listitem><para>Takes a <option>SMACK64</option> security | |
1116 | label as argument. The process executed by the unit will be | |
1117 | started under this label and SMACK will decide whether the | |
b938cb90 | 1118 | process is allowed to run or not, based on it. The process |
798d3a52 ZJS |
1119 | will continue to run under the label specified here unless the |
1120 | executable has its own <option>SMACK64EXEC</option> label, in | |
1121 | which case the process will transition to run under that | |
1122 | label. When not specified, the label that systemd is running | |
1123 | under is used. This directive is ignored if SMACK is | |
1124 | disabled.</para> | |
1125 | ||
1126 | <para>The value may be prefixed by <literal>-</literal>, in | |
1127 | which case all errors will be ignored. An empty value may be | |
1128 | specified to unset previous assignments.</para> | |
1129 | </listitem> | |
1130 | </varlistentry> | |
1131 | ||
1132 | <varlistentry> | |
1133 | <term><varname>IgnoreSIGPIPE=</varname></term> | |
1134 | ||
1135 | <listitem><para>Takes a boolean argument. If true, causes | |
1136 | <constant>SIGPIPE</constant> to be ignored in the executed | |
1137 | process. Defaults to true because <constant>SIGPIPE</constant> | |
1138 | generally is useful only in shell pipelines.</para></listitem> | |
1139 | </varlistentry> | |
1140 | ||
1141 | <varlistentry> | |
1142 | <term><varname>NoNewPrivileges=</varname></term> | |
1143 | ||
1144 | <listitem><para>Takes a boolean argument. If true, ensures | |
1145 | that the service process and all its children can never gain | |
1146 | new privileges. This option is more powerful than the | |
1147 | respective secure bits flags (see above), as it also prohibits | |
1148 | UID changes of any kind. This is the simplest, most effective | |
1149 | way to ensure that a process and its children can never | |
1150 | elevate privileges again.</para></listitem> | |
1151 | </varlistentry> | |
1152 | ||
1153 | <varlistentry> | |
1154 | <term><varname>SystemCallFilter=</varname></term> | |
1155 | ||
1156 | <listitem><para>Takes a space-separated list of system call | |
1157 | names. If this setting is used, all system calls executed by | |
1158 | the unit processes except for the listed ones will result in | |
1159 | immediate process termination with the | |
1160 | <constant>SIGSYS</constant> signal (whitelisting). If the | |
1161 | first character of the list is <literal>~</literal>, the | |
1162 | effect is inverted: only the listed system calls will result | |
1163 | in immediate process termination (blacklisting). If running in | |
19c0b0b9 RC |
1164 | user mode, or in system mode, but without the |
1165 | <constant>CAP_SYS_ADMIN</constant> capabiblity (e.g. setting | |
1166 | <varname>User=nobody</varname>), | |
798d3a52 ZJS |
1167 | <varname>NoNewPrivileges=yes</varname> is implied. This |
1168 | feature makes use of the Secure Computing Mode 2 interfaces of | |
1169 | the kernel ('seccomp filtering') and is useful for enforcing a | |
1170 | minimal sandboxing environment. Note that the | |
1171 | <function>execve</function>, | |
1172 | <function>rt_sigreturn</function>, | |
1173 | <function>sigreturn</function>, | |
1174 | <function>exit_group</function>, <function>exit</function> | |
1175 | system calls are implicitly whitelisted and do not need to be | |
b938cb90 | 1176 | listed explicitly. This option may be specified more than once, |
798d3a52 ZJS |
1177 | in which case the filter masks are merged. If the empty string |
1178 | is assigned, the filter is reset, all prior assignments will | |
1179 | have no effect.</para> | |
1180 | ||
1181 | <para>If you specify both types of this option (i.e. | |
1182 | whitelisting and blacklisting), the first encountered will | |
1183 | take precedence and will dictate the default action | |
1184 | (termination or approval of a system call). Then the next | |
1185 | occurrences of this option will add or delete the listed | |
1186 | system calls from the set of the filtered system calls, | |
1187 | depending of its type and the default action. (For example, if | |
1188 | you have started with a whitelisting of | |
1189 | <function>read</function> and <function>write</function>, and | |
1190 | right after it add a blacklisting of | |
1191 | <function>write</function>, then <function>write</function> | |
1192 | will be removed from the set.) </para></listitem> | |
1193 | </varlistentry> | |
1194 | ||
1195 | <varlistentry> | |
1196 | <term><varname>SystemCallErrorNumber=</varname></term> | |
1197 | ||
1198 | <listitem><para>Takes an <literal>errno</literal> error number | |
1199 | name to return when the system call filter configured with | |
1200 | <varname>SystemCallFilter=</varname> is triggered, instead of | |
1201 | terminating the process immediately. Takes an error name such | |
1202 | as <constant>EPERM</constant>, <constant>EACCES</constant> or | |
1203 | <constant>EUCLEAN</constant>. When this setting is not used, | |
1204 | or when the empty string is assigned, the process will be | |
1205 | terminated immediately when the filter is | |
1206 | triggered.</para></listitem> | |
1207 | </varlistentry> | |
1208 | ||
1209 | <varlistentry> | |
1210 | <term><varname>SystemCallArchitectures=</varname></term> | |
1211 | ||
b938cb90 | 1212 | <listitem><para>Takes a space-separated list of architecture |
798d3a52 ZJS |
1213 | identifiers to include in the system call filter. The known |
1214 | architecture identifiers are <constant>x86</constant>, | |
1215 | <constant>x86-64</constant>, <constant>x32</constant>, | |
1216 | <constant>arm</constant> as well as the special identifier | |
1217 | <constant>native</constant>. Only system calls of the | |
1218 | specified architectures will be permitted to processes of this | |
1219 | unit. This is an effective way to disable compatibility with | |
1220 | non-native architectures for processes, for example to | |
1221 | prohibit execution of 32-bit x86 binaries on 64-bit x86-64 | |
1222 | systems. The special <constant>native</constant> identifier | |
1223 | implicitly maps to the native architecture of the system (or | |
1224 | more strictly: to the architecture the system manager is | |
19c0b0b9 RC |
1225 | compiled for). If running in user mode, or in system mode, |
1226 | but without the <constant>CAP_SYS_ADMIN</constant> | |
1227 | capabiblity (e.g. setting <varname>User=nobody</varname>), | |
1228 | <varname>NoNewPrivileges=yes</varname> is implied. Note | |
798d3a52 ZJS |
1229 | that setting this option to a non-empty list implies that |
1230 | <constant>native</constant> is included too. By default, this | |
1231 | option is set to the empty list, i.e. no architecture system | |
1232 | call filtering is applied.</para></listitem> | |
1233 | </varlistentry> | |
1234 | ||
1235 | <varlistentry> | |
1236 | <term><varname>RestrictAddressFamilies=</varname></term> | |
1237 | ||
1238 | <listitem><para>Restricts the set of socket address families | |
1239 | accessible to the processes of this unit. Takes a | |
1240 | space-separated list of address family names to whitelist, | |
1241 | such as | |
1242 | <constant>AF_UNIX</constant>, | |
1243 | <constant>AF_INET</constant> or | |
1244 | <constant>AF_INET6</constant>. When | |
1245 | prefixed with <constant>~</constant> the listed address | |
1246 | families will be applied as blacklist, otherwise as whitelist. | |
1247 | Note that this restricts access to the | |
3ba3a79d | 1248 | <citerefentry project='man-pages'><refentrytitle>socket</refentrytitle><manvolnum>2</manvolnum></citerefentry> |
798d3a52 ZJS |
1249 | system call only. Sockets passed into the process by other |
1250 | means (for example, by using socket activation with socket | |
1251 | units, see | |
1252 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>) | |
1253 | are unaffected. Also, sockets created with | |
1254 | <function>socketpair()</function> (which creates connected | |
1255 | AF_UNIX sockets only) are unaffected. Note that this option | |
1256 | has no effect on 32-bit x86 and is ignored (but works | |
19c0b0b9 RC |
1257 | correctly on x86-64). If running in user mode, or in system |
1258 | mode, but without the <constant>CAP_SYS_ADMIN</constant> | |
1259 | capabiblity (e.g. setting <varname>User=nobody</varname>), | |
1260 | <varname>NoNewPrivileges=yes</varname> is implied. By | |
798d3a52 ZJS |
1261 | default, no restriction applies, all address families are |
1262 | accessible to processes. If assigned the empty string, any | |
1263 | previous list changes are undone.</para> | |
1264 | ||
1265 | <para>Use this option to limit exposure of processes to remote | |
1266 | systems, in particular via exotic network protocols. Note that | |
1267 | in most cases, the local <constant>AF_UNIX</constant> address | |
1268 | family should be included in the configured whitelist as it is | |
1269 | frequently used for local communication, including for | |
1270 | <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>2</manvolnum></citerefentry> | |
1271 | logging.</para></listitem> | |
1272 | </varlistentry> | |
1273 | ||
1274 | <varlistentry> | |
1275 | <term><varname>Personality=</varname></term> | |
1276 | ||
7882632d LP |
1277 | <listitem><para>Controls which kernel architecture <citerefentry |
1278 | project='man-pages'><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry> shall report, | |
1279 | when invoked by unit processes. Takes one of the architecture identifiers <constant>x86</constant>, | |
1280 | <constant>x86-64</constant>, <constant>ppc</constant>, <constant>ppc-le</constant>, <constant>ppc64</constant>, | |
1281 | <constant>ppc64-le</constant>, <constant>s390</constant> or <constant>s390x</constant>. Which personality | |
1282 | architectures are supported depends on the system architecture. Usually the 64bit versions of the various | |
1283 | system architectures support their immediate 32bit personality architecture counterpart, but no others. For | |
1284 | example, <constant>x86-64</constant> systems support the <constant>x86-64</constant> and | |
1285 | <constant>x86</constant> personalities but no others. The personality feature is useful when running 32-bit | |
1286 | services on a 64-bit host system. If not specified, the personality is left unmodified and thus reflects the | |
1287 | personality of the host system's kernel.</para></listitem> | |
798d3a52 ZJS |
1288 | </varlistentry> |
1289 | ||
1290 | <varlistentry> | |
1291 | <term><varname>RuntimeDirectory=</varname></term> | |
1292 | <term><varname>RuntimeDirectoryMode=</varname></term> | |
1293 | ||
1294 | <listitem><para>Takes a list of directory names. If set, one | |
1295 | or more directories by the specified names will be created | |
1296 | below <filename>/run</filename> (for system services) or below | |
1297 | <varname>$XDG_RUNTIME_DIR</varname> (for user services) when | |
1298 | the unit is started, and removed when the unit is stopped. The | |
1299 | directories will have the access mode specified in | |
1300 | <varname>RuntimeDirectoryMode=</varname>, and will be owned by | |
1301 | the user and group specified in <varname>User=</varname> and | |
1302 | <varname>Group=</varname>. Use this to manage one or more | |
1303 | runtime directories of the unit and bind their lifetime to the | |
1304 | daemon runtime. The specified directory names must be | |
1305 | relative, and may not include a <literal>/</literal>, i.e. | |
1306 | must refer to simple directories to create or remove. This is | |
1307 | particularly useful for unprivileged daemons that cannot | |
1308 | create runtime directories in <filename>/run</filename> due to | |
1309 | lack of privileges, and to make sure the runtime directory is | |
1310 | cleaned up automatically after use. For runtime directories | |
1311 | that require more complex or different configuration or | |
1312 | lifetime guarantees, please consider using | |
1313 | <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
1314 | </varlistentry> | |
1315 | ||
1316 | </variablelist> | |
1317 | </refsect1> | |
1318 | ||
1319 | <refsect1> | |
1320 | <title>Environment variables in spawned processes</title> | |
1321 | ||
1322 | <para>Processes started by the system are executed in a clean | |
1323 | environment in which select variables listed below are set. System | |
1324 | processes started by systemd do not inherit variables from PID 1, | |
1325 | but processes started by user systemd instances inherit all | |
1326 | environment variables from the user systemd instance. | |
1327 | </para> | |
1328 | ||
1329 | <variablelist class='environment-variables'> | |
1330 | <varlistentry> | |
1331 | <term><varname>$PATH</varname></term> | |
1332 | ||
1333 | <listitem><para>Colon-separated list of directories to use | |
1334 | when launching executables. Systemd uses a fixed value of | |
1335 | <filename>/usr/local/sbin</filename>:<filename>/usr/local/bin</filename>:<filename>/usr/sbin</filename>:<filename>/usr/bin</filename>:<filename>/sbin</filename>:<filename>/bin</filename>. | |
1336 | </para></listitem> | |
1337 | </varlistentry> | |
1338 | ||
1339 | <varlistentry> | |
1340 | <term><varname>$LANG</varname></term> | |
1341 | ||
1342 | <listitem><para>Locale. Can be set in | |
3ba3a79d | 1343 | <citerefentry project='man-pages'><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
798d3a52 ZJS |
1344 | or on the kernel command line (see |
1345 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1346 | and | |
1347 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>). | |
1348 | </para></listitem> | |
1349 | </varlistentry> | |
1350 | ||
1351 | <varlistentry> | |
1352 | <term><varname>$USER</varname></term> | |
1353 | <term><varname>$LOGNAME</varname></term> | |
1354 | <term><varname>$HOME</varname></term> | |
1355 | <term><varname>$SHELL</varname></term> | |
1356 | ||
1357 | <listitem><para>User name (twice), home directory, and the | |
1358 | login shell. The variables are set for the units that have | |
1359 | <varname>User=</varname> set, which includes user | |
1360 | <command>systemd</command> instances. See | |
3ba3a79d | 1361 | <citerefentry project='die-net'><refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum></citerefentry>. |
798d3a52 ZJS |
1362 | </para></listitem> |
1363 | </varlistentry> | |
1364 | ||
1365 | <varlistentry> | |
1366 | <term><varname>$XDG_RUNTIME_DIR</varname></term> | |
1367 | ||
1368 | <listitem><para>The directory for volatile state. Set for the | |
1369 | user <command>systemd</command> instance, and also in user | |
1370 | sessions. See | |
1371 | <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>. | |
1372 | </para></listitem> | |
1373 | </varlistentry> | |
1374 | ||
1375 | <varlistentry> | |
1376 | <term><varname>$XDG_SESSION_ID</varname></term> | |
1377 | <term><varname>$XDG_SEAT</varname></term> | |
1378 | <term><varname>$XDG_VTNR</varname></term> | |
1379 | ||
1380 | <listitem><para>The identifier of the session, the seat name, | |
1381 | and virtual terminal of the session. Set by | |
1382 | <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1383 | for login sessions. <varname>$XDG_SEAT</varname> and | |
1384 | <varname>$XDG_VTNR</varname> will only be set when attached to | |
1385 | a seat and a tty.</para></listitem> | |
1386 | </varlistentry> | |
1387 | ||
1388 | <varlistentry> | |
1389 | <term><varname>$MAINPID</varname></term> | |
1390 | ||
1391 | <listitem><para>The PID of the units main process if it is | |
1392 | known. This is only set for control processes as invoked by | |
1393 | <varname>ExecReload=</varname> and similar. </para></listitem> | |
1394 | </varlistentry> | |
1395 | ||
1396 | <varlistentry> | |
1397 | <term><varname>$MANAGERPID</varname></term> | |
1398 | ||
1399 | <listitem><para>The PID of the user <command>systemd</command> | |
1400 | instance, set for processes spawned by it. </para></listitem> | |
1401 | </varlistentry> | |
1402 | ||
1403 | <varlistentry> | |
1404 | <term><varname>$LISTEN_FDS</varname></term> | |
1405 | <term><varname>$LISTEN_PID</varname></term> | |
5c019cf2 | 1406 | <term><varname>$LISTEN_FDNAMES</varname></term> |
798d3a52 ZJS |
1407 | |
1408 | <listitem><para>Information about file descriptors passed to a | |
1409 | service for socket activation. See | |
1410 | <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
1411 | </para></listitem> | |
1412 | </varlistentry> | |
1413 | ||
5c019cf2 EV |
1414 | <varlistentry> |
1415 | <term><varname>$NOTIFY_SOCKET</varname></term> | |
1416 | ||
1417 | <listitem><para>The socket | |
1418 | <function>sd_notify()</function> talks to. See | |
1419 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
1420 | </para></listitem> | |
1421 | </varlistentry> | |
1422 | ||
1423 | <varlistentry> | |
1424 | <term><varname>$WATCHDOG_PID</varname></term> | |
1425 | <term><varname>$WATCHDOG_USEC</varname></term> | |
1426 | ||
1427 | <listitem><para>Information about watchdog keep-alive notifications. See | |
1428 | <citerefentry><refentrytitle>sd_watchdog_enabled</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
1429 | </para></listitem> | |
1430 | </varlistentry> | |
1431 | ||
798d3a52 ZJS |
1432 | <varlistentry> |
1433 | <term><varname>$TERM</varname></term> | |
1434 | ||
1435 | <listitem><para>Terminal type, set only for units connected to | |
1436 | a terminal (<varname>StandardInput=tty</varname>, | |
1437 | <varname>StandardOutput=tty</varname>, or | |
1438 | <varname>StandardError=tty</varname>). See | |
1439 | <citerefentry project='man-pages'><refentrytitle>termcap</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
1440 | </para></listitem> | |
1441 | </varlistentry> | |
1442 | </variablelist> | |
1443 | ||
1444 | <para>Additional variables may be configured by the following | |
1445 | means: for processes spawned in specific units, use the | |
5c019cf2 EV |
1446 | <varname>Environment=</varname>, <varname>EnvironmentFile=</varname> |
1447 | and <varname>PassEnvironment=</varname> options above; to specify | |
798d3a52 ZJS |
1448 | variables globally, use <varname>DefaultEnvironment=</varname> |
1449 | (see | |
1450 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>) | |
1451 | or the kernel option <varname>systemd.setenv=</varname> (see | |
1452 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>). | |
1453 | Additional variables may also be set through PAM, | |
1454 | cf. <citerefentry project='man-pages'><refentrytitle>pam_env</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para> | |
1455 | </refsect1> | |
1456 | ||
1457 | <refsect1> | |
1458 | <title>See Also</title> | |
1459 | <para> | |
1460 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1461 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1462 | <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
1463 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1464 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1465 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1466 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1467 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1468 | <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1469 | <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
a4c18002 | 1470 | <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
798d3a52 ZJS |
1471 | <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
1472 | <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1473 | <citerefentry project='man-pages'><refentrytitle>exec</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
1474 | </para> | |
1475 | </refsect1> | |
dd1eb43b LP |
1476 | |
1477 | </refentry> |