man/systemd.exec.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   4         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   5
   6 <!--
   7   This file is part of systemd.
   8
   9   Copyright 2010 Lennart Poettering
  10
  11   systemd is free software; you can redistribute it and/or modify it
  12   under the terms of the GNU General Public License as published by
  13   the Free Software Foundation; either version 2 of the License, or
  14   (at your option) any later version.
  15
  16   systemd is distributed in the hope that it will be useful, but
  17   WITHOUT ANY WARRANTY; without even the implied warranty of
  18   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19   General Public License for more details.
  20
  21   You should have received a copy of the GNU General Public License
  22   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  23 -->
  24
  25 <refentry id="systemd.exec">
  26         <refentryinfo>
  27                 <title>systemd.exec</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd.exec</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.exec</refname>
  47                 <refpurpose>systemd execution environment configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename>,
  52                 <filename>systemd.socket</filename>,
  53                 <filename>systemd.mount</filename>,
  54                 <filename>systemd.swap</filename></para>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para>Unit configuration files for services, sockets
  61                 mount points and swap devices share a subset of
  62                 configuration options which define the execution
  63                 environment of spawned processes.</para>
  64
  65                 <para>This man page lists the configuration options
  66                 shared by these three unit types. See
  67                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  68                 for the common options of all unit configuration
  69                 files, and
  70                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  71                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  72                 <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  73                 and
  74                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  75                 for more information on the specific unit
  76                 configuration files. The execution specific
  77                 configuration options are configured in the [Service],
  78                 [Socket], [Mount] resp. [Swap] section, depending on the unit
  79                 type.</para>
  80         </refsect1>
  81
  82         <refsect1>
  83                 <title>Options</title>
  84
  85                 <variablelist>
  86
  87                         <varlistentry>
  88                                 <term><varname>WorkingDirectory=</varname></term>
  89
  90                                 <listitem><para>Takes an absolute
  91                                 directory path. Sets the working
  92                                 directory for executed
  93                                 processes.</para></listitem>
  94                         </varlistentry>
  95
  96                         <varlistentry>
  97                                 <term><varname>RootDirectory=</varname></term>
  98
  99                                 <listitem><para>Takes an absolute
 100                                 directory path. Sets the root
 101                                 directory for executed processes, with
 102                                 the
 103                                 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 104                                 system call. If this is used it must
 105                                 be ensured that the process and all
 106                                 its auxiliary files are available in
 107                                 the <function>chroot()</function>
 108                                 jail.</para></listitem>
 109                         </varlistentry>
 110
 111                         <varlistentry>
 112                                 <term><varname>User=</varname></term>
 113                                 <term><varname>Group=</varname></term>
 114
 115                                 <listitem><para>Sets the Unix user
 116                                 resp. group the processes are executed
 117                                 as. Takes a single user resp. group
 118                                 name or ID as argument. If no group is
 119                                 set the default group of the user is
 120                                 chosen.</para></listitem>
 121                         </varlistentry>
 122
 123                         <varlistentry>
 124                                 <term><varname>SupplementaryGroups=</varname></term>
 125
 126                                 <listitem><para>Sets the supplementary
 127                                 Unix groups the processes are executed
 128                                 as. This takes a space separated list
 129                                 of group names or IDs. This option may
 130                                 be specified more than once in which
 131                                 case all listed groups are set as
 132                                 supplementary groups. This option does
 133                                 not override but extends the list of
 134                                 supplementary groups configured in the
 135                                 system group database for the
 136                                 user.</para></listitem>
 137                         </varlistentry>
 138
 139                         <varlistentry>
 140                                 <term><varname>Nice=</varname></term>
 141
 142                                 <listitem><para>Sets the default nice
 143                                 level (scheduling priority) for
 144                                 executed processes. Takes an integer
 145                                 between -20 (highest priority) and 19
 146                                 (lowest priority). See
 147                                 <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 148                                 for details.</para></listitem>
 149                         </varlistentry>
 150
 151                         <varlistentry>
 152                                 <term><varname>OOMScoreAdjust=</varname></term>
 153
 154                                 <listitem><para>Sets the adjustment
 155                                 level for the Out-Of-Memory killer for
 156                                 executed processes. Takes an integer
 157                                 between -1000 (to disable OOM killing
 158                                 for this process) and 1000 (to make
 159                                 killing of this process under memory
 160                                 pressure very likely). See <ulink
 161                                 url="http://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
 162                                 for details.</para></listitem>
 163                         </varlistentry>
 164
 165                         <varlistentry>
 166                                 <term><varname>IOSchedulingClass=</varname></term>
 167
 168                                 <listitem><para>Sets the IO scheduling
 169                                 class for executed processes. Takes an
 170                                 integer between 0 and 3 or one of the
 171                                 strings <option>none</option>,
 172                                 <option>realtime</option>,
 173                                 <option>best-effort</option> or
 174                                 <option>idle</option>. See
 175                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 176                                 for details.</para></listitem>
 177                         </varlistentry>
 178
 179                         <varlistentry>
 180                                 <term><varname>IOSchedulingPriority=</varname></term>
 181
 182                                 <listitem><para>Sets the IO scheduling
 183                                 priority for executed processes. Takes
 184                                 an integer between 0 (highest
 185                                 priority) and 7 (lowest priority). The
 186                                 available priorities depend on the
 187                                 selected IO scheduling class (see
 188                                 above). See
 189                                 <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 190                                 for details.</para></listitem>
 191                         </varlistentry>
 192
 193                         <varlistentry>
 194                                 <term><varname>CPUSchedulingPolicy=</varname></term>
 195
 196                                 <listitem><para>Sets the CPU
 197                                 scheduling policy for executed
 198                                 processes. Takes one of
 199                                 <option>other</option>,
 200                                 <option>batch</option>,
 201                                 <option>idle</option>,
 202                                 <option>fifo</option> or
 203                                 <option>rr</option>. See
 204                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 205                                 for details.</para></listitem>
 206                         </varlistentry>
 207
 208                         <varlistentry>
 209                                 <term><varname>CPUSchedulingPriority=</varname></term>
 210
 211                                 <listitem><para>Sets the CPU
 212                                 scheduling priority for executed
 213                                 processes. Takes an integer between 1
 214                                 (lowest priority) and 99 (highest
 215                                 priority). The available priority
 216                                 range depends on the selected CPU
 217                                 scheduling policy (see above). See
 218                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 219                                 for details.</para></listitem>
 220                         </varlistentry>
 221
 222                         <varlistentry>
 223                                 <term><varname>CPUSchedulingResetOnFork=</varname></term>
 224
 225                                 <listitem><para>Takes a boolean
 226                                 argument. If true elevated CPU
 227                                 scheduling priorities and policies
 228                                 will be reset when the executed
 229                                 processes fork, and can hence not leak
 230                                 into child processes. See
 231                                 <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 232                                 for details. Defaults to false.</para></listitem>
 233                         </varlistentry>
 234
 235                         <varlistentry>
 236                                 <term><varname>CPUAffinity=</varname></term>
 237
 238                                 <listitem><para>Controls the CPU
 239                                 affinity of the executed
 240                                 processes. Takes a space-separated
 241                                 list of CPU indexes. See
 242                                 <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 243                                 for details.</para></listitem>
 244                         </varlistentry>
 245
 246                         <varlistentry>
 247                                 <term><varname>UMask=</varname></term>
 248
 249                                 <listitem><para>Controls the file mode
 250                                 creation mask. Takes an access mode in
 251                                 octal notation. See
 252                                 <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 253                                 for details. Defaults to
 254                                 0002.</para></listitem>
 255                         </varlistentry>
 256
 257                         <varlistentry>
 258                                 <term><varname>Environment=</varname></term>
 259
 260                                 <listitem><para>Sets environment
 261                                 variables for executed
 262                                 processes. Takes a space-separated
 263                                 list of variable assignments. This
 264                                 option may be specified more than once
 265                                 in which case all listed variables
 266                                 will be set. If the same variable is
 267                                 set twice the later setting will
 268                                 override the earlier setting. See
 269                                 <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 270                                 for details.</para></listitem>
 271                         </varlistentry>
 272                         <varlistentry>
 273                                 <term><varname>EnvironmentFile=</varname></term>
 274                                 <listitem><para>Similar to
 275                                 <varname>Environment=</varname> but
 276                                 reads the environment variables from a
 277                                 text file. The text file should
 278                                 contain new-line separated variable
 279                                 assignments. Empty lines and lines
 280                                 starting with ; or # will be ignored,
 281                                 which may be used for commenting. The
 282                                 argument passed should be an absolute
 283                                 file name, optionally prefixed with
 284                                 "-", which indicates that if the file
 285                                 does not exist it won't be read and no
 286                                 error or warning message is
 287                                 logged.</para></listitem>
 288                         </varlistentry>
 289
 290                         <varlistentry>
 291                                 <term><varname>StandardInput=</varname></term>
 292                                 <listitem><para>Controls where file
 293                                 descriptor 0 (STDIN) of the executed
 294                                 processes is connected to. Takes one
 295                                 of <option>null</option>,
 296                                 <option>tty</option>,
 297                                 <option>tty-force</option>,
 298                                 <option>tty-fail</option> or
 299                                 <option>socket</option>. If
 300                                 <option>null</option> is selected
 301                                 standard input will be connected to
 302                                 <filename>/dev/null</filename>,
 303                                 i.e. all read attempts by the process
 304                                 will result in immediate EOF. If
 305                                 <option>tty</option> is selected
 306                                 standard input is connected to a TTY
 307                                 (as configured by
 308                                 <varname>TTYPath=</varname>, see
 309                                 below) and the executed process
 310                                 becomes the controlling process of the
 311                                 terminal. If the terminal is already
 312                                 being controlled by another process the
 313                                 executed process waits until the current
 314                                 controlling process releases the
 315                                 terminal.
 316                                 <option>tty-force</option>
 317                                 is similar to <option>tty</option>,
 318                                 but the executed process is forcefully
 319                                 and immediately made the controlling
 320                                 process of the terminal, potentially
 321                                 removing previous controlling
 322                                 processes from the
 323                                 terminal. <option>tty-fail</option> is
 324                                 similar to <option>tty</option> but if
 325                                 the terminal already has a controlling
 326                                 process start-up of the executed
 327                                 process fails.  The
 328                                 <option>socket</option> option is only
 329                                 valid in socket-activated services,
 330                                 and only when the socket configuration
 331                                 file (see
 332                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 333                                 for details) specifies a single socket
 334                                 only. If this option is set standard
 335                                 input will be connected to the socket
 336                                 the service was activated from, which
 337                                 is primarily useful for compatibility
 338                                 with daemons designed for use with the
 339                                 traditional
 340                                 <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 341                                 daemon. This setting defaults to
 342                                 <option>null</option>.</para></listitem>
 343                         </varlistentry>
 344                         <varlistentry>
 345                                 <term><varname>StandardOutput=</varname></term>
 346                                 <listitem><para>Controls where file
 347                                 descriptor 1 (STDOUT) of the executed
 348                                 processes is connected to. Takes one
 349                                 of <option>inherit</option>,
 350                                 <option>null</option>,
 351                                 <option>tty</option>,
 352                                 <option>syslog</option>,
 353                                 <option>kmsg</option> or
 354                                 <option>socket</option>. If set to
 355                                 <option>inherit</option> the file
 356                                 descriptor of standard input is
 357                                 duplicated for standard output. If set
 358                                 to <option>null</option> standard
 359                                 output will be connected to
 360                                 <filename>/dev/null</filename>,
 361                                 i.e. everything written to it will be
 362                                 lost. If set to <option>tty</option>
 363                                 standard output will be connected to a
 364                                 tty (as configured via
 365                                 <varname>TTYPath=</varname>, see
 366                                 below). If the TTY is used for output
 367                                 only the executed process will not
 368                                 become the controlling process of the
 369                                 terminal, and will not fail or wait
 370                                 for other processes to release the
 371                                 terminal. <option>syslog</option>
 372                                 connects standard output to the
 373                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 374                                 system logger. <option>kmsg</option>
 375                                 connects it with the kernel log buffer
 376                                 which is accessible via
 377                                 <citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>socket</option>
 378                                 connects standard output to a socket
 379                                 from socket activation, semantics are
 380                                 similar to the respective option of
 381                                 <varname>StandardInput=</varname>.
 382                                 This setting defaults to
 383                                 <option>inherit</option>.</para></listitem>
 384                         </varlistentry>
 385                         <varlistentry>
 386                                 <term><varname>StandardError=</varname></term>
 387                                 <listitem><para>Controls where file
 388                                 descriptor 2 (STDERR) of the executed
 389                                 processes is connected to. The
 390                                 available options are identical to
 391                                 those of
 392                                 <varname>StandardOutput=</varname>,
 393                                 with one exception: if set to
 394                                 <option>inherit</option> the file
 395                                 descriptor used for standard output is
 396                                 duplicated for standard error. This
 397                                 setting defaults to
 398                                 <option>inherit</option>.</para></listitem>
 399                         </varlistentry>
 400                         <varlistentry>
 401                                 <term><varname>TTYPath=</varname></term>
 402                                 <listitem><para>Sets the terminal
 403                                 device node to use if standard input,
 404                                 output or stderr are connected to a
 405                                 TTY (see above). Defaults to
 406                                 <filename>/dev/console</filename>.</para></listitem>
 407                         </varlistentry>
 408                         <varlistentry>
 409                                 <term><varname>SyslogIdentifer=</varname></term>
 410                                 <listitem><para>Sets the process name
 411                                 to prefix log lines sent to syslog or
 412                                 the kernel log buffer with. If not set
 413                                 defaults to the process name of the
 414                                 executed process. This option is only
 415                                 useful when
 416                                 <varname>StandardOutput=</varname> or
 417                                 <varname>StandardError=</varname> are
 418                                 set to <option>syslog</option> or
 419                                 <option>kmsg</option>.</para></listitem>
 420                         </varlistentry>
 421                         <varlistentry>
 422                                 <term><varname>SyslogFacility=</varname></term>
 423                                 <listitem><para>Sets the syslog
 424                                 facility to use when logging to
 425                                 syslog. One of <option>kern</option>,
 426                                 <option>user</option>,
 427                                 <option>mail</option>,
 428                                 <option>daemon</option>,
 429                                 <option>auth</option>,
 430                                 <option>syslog</option>,
 431                                 <option>lpr</option>,
 432                                 <option>news</option>,
 433                                 <option>uucp</option>,
 434                                 <option>cron</option>,
 435                                 <option>authpriv</option>,
 436                                 <option>ftp</option>,
 437                                 <option>local0</option>,
 438                                 <option>local1</option>,
 439                                 <option>local2</option>,
 440                                 <option>local3</option>,
 441                                 <option>local4</option>,
 442                                 <option>local5</option>,
 443                                 <option>local6</option> or
 444                                 <option>local7</option>. See
 445                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 446                                 for details. This option is only
 447                                 useful when
 448                                 <varname>StandardOutput=</varname> or
 449                                 <varname>StandardError=</varname> are
 450                                 set to <option>syslog</option>.
 451                                 Defaults to
 452                                 <option>daemon</option>.</para></listitem>
 453                         </varlistentry>
 454                         <varlistentry>
 455                                 <term><varname>SyslogLevel=</varname></term>
 456                                 <listitem><para>Default syslog level
 457                                 to use when logging to syslog or the
 458                                 kernel log buffer. One of
 459                                 <option>emerg</option>,
 460                                 <option>alert</option>,
 461                                 <option>crit</option>,
 462                                 <option>err</option>,
 463                                 <option>warning</option>,
 464                                 <option>notice</option>,
 465                                 <option>info</option>,
 466                                 <option>debug</option>. See
 467                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 468                                 for details. This option is only
 469                                 useful when
 470                                 <varname>StandardOutput=</varname> or
 471                                 <varname>StandardError=</varname> are
 472                                 set to <option>syslog</option> or
 473                                 <option>kmsg</option>. Note that
 474                                 individual lines output by the daemon
 475                                 might be prefixed with a different log
 476                                 level which can be used to override
 477                                 the default log level specified
 478                                 here. The interpretation of these
 479                                 prefixes may be disabled with
 480                                 <varname>SyslogLevelPrefix=</varname>,
 481                                 see below. For details see
 482                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
 483
 484                                 Defaults to
 485                                 <option>info</option>.</para></listitem>
 486                         </varlistentry>
 487
 488                         <varlistentry>
 489                                 <term><varname>SyslogLevelPrefix=</varname></term>
 490                                 <listitem><para>Takes a boolean
 491                                 argument. If true and
 492                                 <varname>StandardOutput=</varname> or
 493                                 <varname>StandardError=</varname> are
 494                                 set to <option>syslog</option> or
 495                                 <option>kmsg</option> log lines
 496                                 written by the executed process that
 497                                 are prefixed with a log level will be
 498                                 passed on to syslog with this log
 499                                 level set but the prefix removed. If
 500                                 set to false, the interpretation of
 501                                 these prefixes is disabled and the
 502                                 logged lines are passed on as-is. For
 503                                 details about this prefixing see
 504                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
 505                                 Defaults to true.</para></listitem>
 506                         </varlistentry>
 507
 508                         <varlistentry>
 509                                 <term><varname>TimerSlackNSec=</varname></term>
 510                                 <listitem><para>Sets the timer slack
 511                                 in nanoseconds for the executed
 512                                 processes. The timer slack controls the
 513                                 accuracy of wake-ups triggered by
 514                                 timers. See
 515                                 <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 516                                 for more information. Note that in
 517                                 contrast to most other time span
 518                                 definitions this parameter takes an
 519                                 integer value in nano-seconds and does
 520                                 not understand any other
 521                                 units.</para></listitem>
 522                         </varlistentry>
 523
 524                         <varlistentry>
 525                                 <term><varname>LimitCPU=</varname></term>
 526                                 <term><varname>LimitFSIZE=</varname></term>
 527                                 <term><varname>LimitDATA=</varname></term>
 528                                 <term><varname>LimitSTACK=</varname></term>
 529                                 <term><varname>LimitCORE=</varname></term>
 530                                 <term><varname>LimitRSS=</varname></term>
 531                                 <term><varname>LimitNOFILE=</varname></term>
 532                                 <term><varname>LimitAS=</varname></term>
 533                                 <term><varname>LimitNPROC=</varname></term>
 534                                 <term><varname>LimitMEMLOCK=</varname></term>
 535                                 <term><varname>LimitLOCKS=</varname></term>
 536                                 <term><varname>LimitSIGPENDING=</varname></term>
 537                                 <term><varname>LimitMSGQUEUE=</varname></term>
 538                                 <term><varname>LimitNICE=</varname></term>
 539                                 <term><varname>LimitRTPRIO=</varname></term>
 540                                 <term><varname>LimitRTTIME=</varname></term>
 541                                 <listitem><para>These settings control
 542                                 various resource limits for executed
 543                                 processes. See
 544                                 <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 545                                 for details.</para></listitem>
 546                         </varlistentry>
 547
 548                         <varlistentry>
 549                                 <term><varname>PAMName=</varname></term>
 550                                 <listitem><para>Sets the PAM service
 551                                 name to set up a session as. If set
 552                                 the executed process will be
 553                                 registered as a PAM session under the
 554                                 specified service name. This is only
 555                                 useful in conjunction with the
 556                                 <varname>User=</varname> setting. If
 557                                 not set no PAM session will be opened
 558                                 for the executed processes. See
 559                                 <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 560                                 for details.</para></listitem>
 561                         </varlistentry>
 562
 563                         <varlistentry>
 564                                 <term><varname>TCPWrapName=</varname></term>
 565                                 <listitem><para>If this is a
 566                                 socket-activated service this sets the
 567                                 tcpwrap service name to check the
 568                                 permission for the current connection
 569                                 with. This is only useful in
 570                                 conjunction with socket-activated
 571                                 services, and stream sockets (TCP) in
 572                                 particular. It has no effect on other
 573                                 socket types (e.g. datagram/UDP) and on processes
 574                                 unrelated to socket-based
 575                                 activation. If the tcpwrap
 576                                 verification fails daemon start-up
 577                                 will fail and the connection is
 578                                 terminated. See
 579                                 <citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 580                                 for details.</para></listitem>
 581                         </varlistentry>
 582
 583                         <varlistentry>
 584                                 <term><varname>Capabilities=</varname></term>
 585                                 <listitem><para>Controls the
 586                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 587                                 set for the executed process. Take a
 588                                 capability string as described in
 589                                 <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 590                                 Note that this capability set is
 591                                 usually influenced by the capabilities
 592                                 attached to the executed
 593                                 file.</para></listitem>
 594                         </varlistentry>
 595
 596                         <varlistentry>
 597                                 <term><varname>SecureBits=</varname></term>
 598                                 <listitem><para>Controls the secure
 599                                 bits set for the executed process. See
 600                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 601                                 for details. Takes a list of strings:
 602                                 <option>keep-caps</option>,
 603                                 <option>keep-caps-locked</option>,
 604                                 <option>no-setuid-fixup</option>,
 605                                 <option>no-setuid-fixup-locked</option>,
 606                                 <option>no-setuid-noroot</option> and/or
 607                                 <option>no-setuid-noroot-locked</option>.
 608                                 </para></listitem>
 609                         </varlistentry>
 610
 611                         <varlistentry>
 612                                 <term><varname>CapabilityBoundingSetDrop=</varname></term>
 613
 614                                 <listitem><para>Controls the
 615                                 capability bounding set drop set for
 616                                 the executed process. See
 617                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 618                                 for details. Takes a list of
 619                                 capability names as read by
 620                                 <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 621                                 </para></listitem>
 622                         </varlistentry>
 623
 624                         <varlistentry>
 625                                 <term><varname>ControlGroup=</varname></term>
 626
 627                                 <listitem><para>Controls the control
 628                                 groups the executed processes shall be
 629                                 made members of. Takes a
 630                                 space-separated list of cgroup
 631                                 identifiers. A cgroup identifier has a
 632                                 format like
 633                                 <filename>cpu:/foo/bar</filename>,
 634                                 where "cpu" identifies the kernel
 635                                 control group controller used, and
 636                                 <filename>/foo/bar</filename> is the
 637                                 control group path. The controller name
 638                                 and ":" may be omitted in which case
 639                                 the named systemd control group
 640                                 hierarchy is implied. Alternatively,
 641                                 the path and ":" may be omitted, in
 642                                 which case the default control group
 643                                 path for this unit is implied. This
 644                                 option may be used to place executed
 645                                 processes in arbitrary groups in
 646                                 arbitrary hierachies -- which can be
 647                                 configured externally with additional execution limits. By default
 648                                 systemd will place all executed
 649                                 processes in separate per-unit control
 650                                 groups (named after the unit) in the
 651                                 systemd named hierarchy. Since every
 652                                 process can be in one group per
 653                                 hierarchy only overriding the control group
 654                                 path in the named systemd hierarchy
 655                                 will disable automatic placement in
 656                                 the default group. For details about control
 657                                 groups see <ulink
 658                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
 659                         </varlistentry>
 660
 661                         <varlistentry>
 662                                 <term><varname>ReadWriteDirectories=</varname></term>
 663                                 <term><varname>ReadOnlyDirectories=</varname></term>
 664                                 <term><varname>InaccessibleDirectories=</varname></term>
 665
 666                                 <listitem><para>Sets up a new
 667                                 file-system name space for executed
 668                                 processes. These options may be used
 669                                 to limit access a process might have
 670                                 to the main file-system
 671                                 hierarchy. Each setting takes a
 672                                 space-separated list of absolute
 673                                 directory paths. Directories listed in
 674                                 <varname>ReadWriteDirectories=</varname>
 675                                 are accessible from within the
 676                                 namespace with the same access rights
 677                                 as from outside. Directories listed in
 678                                 <varname>ReadOnlyDirectories=</varname>
 679                                 are accessible for reading only,
 680                                 writing will be refused even if the
 681                                 usual file access controls would
 682                                 permit this. Directories listed in
 683                                 <varname>InaccessibleDirectories=</varname>
 684                                 will be made inaccesible for processes
 685                                 inside the namespace. Note that
 686                                 restricting access with these options
 687                                 does not extend to submounts of a
 688                                 directory. You must list submounts
 689                                 separately in these settings to
 690                                 ensure the same limited access. These
 691                                 options may be specified more than
 692                                 once in which case all directories
 693                                 listed will have limited access from
 694                                 within the
 695                                 namespace.</para></listitem>
 696                         </varlistentry>
 697
 698                         <varlistentry>
 699                                 <term><varname>PrivateTmp=</varname></term>
 700
 701                                 <listitem><para>Takes a boolean
 702                                 argument. If true sets up a new
 703                                 namespace for the executed processes
 704                                 and mounts a private
 705                                 <filename>/tmp</filename> directory
 706                                 inside it, that is not shared by
 707                                 processes outside of the
 708                                 namespace. This is useful to secure
 709                                 access to temporary files of the
 710                                 process, but makes sharing between
 711                                 processes via
 712                                 <filename>/tmp</filename>
 713                                 impossible. Defaults to false.</para></listitem>
 714                         </varlistentry>
 715
 716                         <varlistentry>
 717                                 <term><varname>MountFlags=</varname></term>
 718
 719                                 <listitem><para>Takes a mount
 720                                 propagation flag:
 721                                 <option>shared</option>,
 722                                 <option>slave</option> or
 723                                 <option>private</option>, which
 724                                 control whether namespaces set up with
 725                                 <varname>ReadWriteDirectories=</varname>,
 726                                 <varname>ReadOnlyDirectories=</varname>
 727                                 and
 728                                 <varname>InaccessibleDirectories=</varname>
 729                                 receive or propagate new mounts
 730                                 from/to the main namespace. See
 731                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 732                                 for details. Defaults to
 733                                 <option>shared</option>, i.e. the new
 734                                 namespace will both receive new mount
 735                                 points from the main namespace as well
 736                                 as propagate new mounts to
 737                                 it.</para></listitem>
 738                         </varlistentry>
 739
 740                         <varlistentry>
 741                                 <term><varname>UtmpIdentifier=</varname></term>
 742
 743                                 <listitem><para>Takes a a four
 744                                 character identifier string for an
 745                                 utmp/wtmp entry for this service. This
 746                                 should only be set for services such
 747                                 as <command>getty</command>
 748                                 implementations where utmp/wtmp
 749                                 entries must be created and cleared
 750                                 before and after execution. If the
 751                                 configured string is longer than four
 752                                 characters it is truncated and the
 753                                 terminal four characters are
 754                                 used. This setting interprets %I style
 755                                 string replacements. This setting is
 756                                 unset by default, i.e. no utmp/wtmp
 757                                 entries are created or cleaned up for
 758                                 this service.</para></listitem>
 759                         </varlistentry>
 760
 761                 </variablelist>
 762         </refsect1>
 763
 764         <refsect1>
 765                   <title>See Also</title>
 766                   <para>
 767                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 768                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 769                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 770                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 771                           <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 772                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 773                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 774                   </para>
 775         </refsect1>
 776
 777 </refentry>