man/systemd.exec.xml

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   9   Copyright 2010 Lennart Poettering
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  24
  25 <refentry id="systemd.exec">
  26         <refentryinfo>
  27                 <title>systemd.exec</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd.exec</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.exec</refname>
  47                 <refpurpose>systemd execution environment configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename>,
  52                 <filename>systemd.socket</filename>,
  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 four 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                                 0022.</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                                 parser strips leading and
 283                                 trailing whitespace from the values
 284                                 of assignments, unless you use
 285                                 double quotes (").
 286                                 The
 287                                 argument passed should be an absolute
 288                                 file name, optionally prefixed with
 289                                 "-", which indicates that if the file
 290                                 does not exist it won't be read and no
 291                                 error or warning message is
 292                                 logged. The files listed with this
 293                                 directive will be read shortly before
 294                                 the process is executed. Settings from
 295                                 these files override settings made
 296                                 with
 297                                 <varname>Environment=</varname>. If
 298                                 the same variable is set twice from
 299                                 these files the files will be read in
 300                                 the order they are specified and the
 301                                 later setting will override the
 302                                 earlier setting. </para></listitem>
 303                         </varlistentry>
 304
 305                         <varlistentry>
 306                                 <term><varname>StandardInput=</varname></term>
 307                                 <listitem><para>Controls where file
 308                                 descriptor 0 (STDIN) of the executed
 309                                 processes is connected to. Takes one
 310                                 of <option>null</option>,
 311                                 <option>tty</option>,
 312                                 <option>tty-force</option>,
 313                                 <option>tty-fail</option> or
 314                                 <option>socket</option>. If
 315                                 <option>null</option> is selected
 316                                 standard input will be connected to
 317                                 <filename>/dev/null</filename>,
 318                                 i.e. all read attempts by the process
 319                                 will result in immediate EOF. If
 320                                 <option>tty</option> is selected
 321                                 standard input is connected to a TTY
 322                                 (as configured by
 323                                 <varname>TTYPath=</varname>, see
 324                                 below) and the executed process
 325                                 becomes the controlling process of the
 326                                 terminal. If the terminal is already
 327                                 being controlled by another process the
 328                                 executed process waits until the current
 329                                 controlling process releases the
 330                                 terminal.
 331                                 <option>tty-force</option>
 332                                 is similar to <option>tty</option>,
 333                                 but the executed process is forcefully
 334                                 and immediately made the controlling
 335                                 process of the terminal, potentially
 336                                 removing previous controlling
 337                                 processes from the
 338                                 terminal. <option>tty-fail</option> is
 339                                 similar to <option>tty</option> but if
 340                                 the terminal already has a controlling
 341                                 process start-up of the executed
 342                                 process fails.  The
 343                                 <option>socket</option> option is only
 344                                 valid in socket-activated services,
 345                                 and only when the socket configuration
 346                                 file (see
 347                                 <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 348                                 for details) specifies a single socket
 349                                 only. If this option is set standard
 350                                 input will be connected to the socket
 351                                 the service was activated from, which
 352                                 is primarily useful for compatibility
 353                                 with daemons designed for use with the
 354                                 traditional
 355                                 <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 356                                 daemon. This setting defaults to
 357                                 <option>null</option>.</para></listitem>
 358                         </varlistentry>
 359                         <varlistentry>
 360                                 <term><varname>StandardOutput=</varname></term>
 361                                 <listitem><para>Controls where file
 362                                 descriptor 1 (STDOUT) of the executed
 363                                 processes is connected to. Takes one
 364                                 of <option>inherit</option>,
 365                                 <option>null</option>,
 366                                 <option>tty</option>,
 367                                 <option>syslog</option>,
 368                                 <option>kmsg</option>,
 369                                 <option>kmsg+console</option>,
 370                                 <option>syslog+console</option> or
 371                                 <option>socket</option>. If set to
 372                                 <option>inherit</option> the file
 373                                 descriptor of standard input is
 374                                 duplicated for standard output. If set
 375                                 to <option>null</option> standard
 376                                 output will be connected to
 377                                 <filename>/dev/null</filename>,
 378                                 i.e. everything written to it will be
 379                                 lost. If set to <option>tty</option>
 380                                 standard output will be connected to a
 381                                 tty (as configured via
 382                                 <varname>TTYPath=</varname>, see
 383                                 below). If the TTY is used for output
 384                                 only the executed process will not
 385                                 become the controlling process of the
 386                                 terminal, and will not fail or wait
 387                                 for other processes to release the
 388                                 terminal. <option>syslog</option>
 389                                 connects standard output to the
 390                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 391                                 system syslog
 392                                 service. <option>kmsg</option>
 393                                 connects it with the kernel log buffer
 394                                 which is accessible via
 395                                 <citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>syslog+console</option>
 396                                 and <option>kmsg+console</option> work
 397                                 similarly but copy the output to the
 398                                 system console as
 399                                 well. <option>socket</option> connects
 400                                 standard output to a socket from
 401                                 socket activation, semantics are
 402                                 similar to the respective option of
 403                                 <varname>StandardInput=</varname>.
 404                                 This setting defaults to the value set
 405                                 with
 406                                 <option>DefaultStandardOutput=</option>
 407                                 in
 408                                 <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 409                                 which defaults to
 410                                 <option>syslog</option>.</para></listitem>
 411                         </varlistentry>
 412                         <varlistentry>
 413                                 <term><varname>StandardError=</varname></term>
 414                                 <listitem><para>Controls where file
 415                                 descriptor 2 (STDERR) of the executed
 416                                 processes is connected to. The
 417                                 available options are identical to
 418                                 those of
 419                                 <varname>StandardOutput=</varname>,
 420                                 with one exception: if set to
 421                                 <option>inherit</option> the file
 422                                 descriptor used for standard output is
 423                                 duplicated for standard error. This
 424                                 setting defaults to the value set with
 425                                 <option>DefaultStandardError=</option>
 426                                 in
 427                                 <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 428                                 which defaults to
 429                                 <option>inherit</option>.</para></listitem>
 430                         </varlistentry>
 431                         <varlistentry>
 432                                 <term><varname>TTYPath=</varname></term>
 433                                 <listitem><para>Sets the terminal
 434                                 device node to use if standard input,
 435                                 output or stderr are connected to a
 436                                 TTY (see above). Defaults to
 437                                 <filename>/dev/console</filename>.</para></listitem>
 438                         </varlistentry>
 439                         <varlistentry>
 440                                 <term><varname>TTYReset=</varname></term>
 441                                 <listitem><para>Reset the terminal
 442                                 device specified with
 443                                 <varname>TTYPath=</varname> before and
 444                                 after execution. Defaults to
 445                                 <literal>no</literal>.</para></listitem>
 446                         </varlistentry>
 447                         <varlistentry>
 448                                 <term><varname>TTYVHangup=</varname></term>
 449                                 <listitem><para>Disconnect all clients
 450                                 which have opened the terminal device
 451                                 specified with
 452                                 <varname>TTYPath=</varname>
 453                                 before and after execution. Defaults
 454                                 to
 455                                 <literal>no</literal>.</para></listitem>
 456                         </varlistentry>
 457                         <varlistentry>
 458                                 <term><varname>TTYVTDisallocate=</varname></term>
 459                                 <listitem><para>If the the terminal
 460                                 device specified with
 461                                 <varname>TTYPath=</varname> is a
 462                                 virtual console terminal try to
 463                                 deallocate the TTY before and after
 464                                 execution. This ensures that the
 465                                 screen and scrollback buffer is
 466                                 cleared. Defaults to
 467                                 <literal>no</literal>.</para></listitem>
 468                         </varlistentry>
 469                         <varlistentry>
 470                                 <term><varname>SyslogIdentifier=</varname></term>
 471                                 <listitem><para>Sets the process name
 472                                 to prefix log lines sent to syslog or
 473                                 the kernel log buffer with. If not set
 474                                 defaults to the process name of the
 475                                 executed process. This option is only
 476                                 useful when
 477                                 <varname>StandardOutput=</varname> or
 478                                 <varname>StandardError=</varname> are
 479                                 set to <option>syslog</option> or
 480                                 <option>kmsg</option>.</para></listitem>
 481                         </varlistentry>
 482                         <varlistentry>
 483                                 <term><varname>SyslogFacility=</varname></term>
 484                                 <listitem><para>Sets the syslog
 485                                 facility to use when logging to
 486                                 syslog. One of <option>kern</option>,
 487                                 <option>user</option>,
 488                                 <option>mail</option>,
 489                                 <option>daemon</option>,
 490                                 <option>auth</option>,
 491                                 <option>syslog</option>,
 492                                 <option>lpr</option>,
 493                                 <option>news</option>,
 494                                 <option>uucp</option>,
 495                                 <option>cron</option>,
 496                                 <option>authpriv</option>,
 497                                 <option>ftp</option>,
 498                                 <option>local0</option>,
 499                                 <option>local1</option>,
 500                                 <option>local2</option>,
 501                                 <option>local3</option>,
 502                                 <option>local4</option>,
 503                                 <option>local5</option>,
 504                                 <option>local6</option> or
 505                                 <option>local7</option>. See
 506                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 507                                 for details. This option is only
 508                                 useful when
 509                                 <varname>StandardOutput=</varname> or
 510                                 <varname>StandardError=</varname> are
 511                                 set to <option>syslog</option>.
 512                                 Defaults to
 513                                 <option>daemon</option>.</para></listitem>
 514                         </varlistentry>
 515                         <varlistentry>
 516                                 <term><varname>SyslogLevel=</varname></term>
 517                                 <listitem><para>Default syslog level
 518                                 to use when logging to syslog or the
 519                                 kernel log buffer. One of
 520                                 <option>emerg</option>,
 521                                 <option>alert</option>,
 522                                 <option>crit</option>,
 523                                 <option>err</option>,
 524                                 <option>warning</option>,
 525                                 <option>notice</option>,
 526                                 <option>info</option>,
 527                                 <option>debug</option>. See
 528                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 529                                 for details. This option is only
 530                                 useful when
 531                                 <varname>StandardOutput=</varname> or
 532                                 <varname>StandardError=</varname> are
 533                                 set to <option>syslog</option> or
 534                                 <option>kmsg</option>. Note that
 535                                 individual lines output by the daemon
 536                                 might be prefixed with a different log
 537                                 level which can be used to override
 538                                 the default log level specified
 539                                 here. The interpretation of these
 540                                 prefixes may be disabled with
 541                                 <varname>SyslogLevelPrefix=</varname>,
 542                                 see below. For details see
 543                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
 544
 545                                 Defaults to
 546                                 <option>info</option>.</para></listitem>
 547                         </varlistentry>
 548
 549                         <varlistentry>
 550                                 <term><varname>SyslogLevelPrefix=</varname></term>
 551                                 <listitem><para>Takes a boolean
 552                                 argument. If true and
 553                                 <varname>StandardOutput=</varname> or
 554                                 <varname>StandardError=</varname> are
 555                                 set to <option>syslog</option> or
 556                                 <option>kmsg</option> log lines
 557                                 written by the executed process that
 558                                 are prefixed with a log level will be
 559                                 passed on to syslog with this log
 560                                 level set but the prefix removed. If
 561                                 set to false, the interpretation of
 562                                 these prefixes is disabled and the
 563                                 logged lines are passed on as-is. For
 564                                 details about this prefixing see
 565                                 <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
 566                                 Defaults to true.</para></listitem>
 567                         </varlistentry>
 568
 569                         <varlistentry>
 570                                 <term><varname>TimerSlackNSec=</varname></term>
 571                                 <listitem><para>Sets the timer slack
 572                                 in nanoseconds for the executed
 573                                 processes. The timer slack controls the
 574                                 accuracy of wake-ups triggered by
 575                                 timers. See
 576                                 <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 577                                 for more information. Note that in
 578                                 contrast to most other time span
 579                                 definitions this parameter takes an
 580                                 integer value in nano-seconds and does
 581                                 not understand any other
 582                                 units.</para></listitem>
 583                         </varlistentry>
 584
 585                         <varlistentry>
 586                                 <term><varname>LimitCPU=</varname></term>
 587                                 <term><varname>LimitFSIZE=</varname></term>
 588                                 <term><varname>LimitDATA=</varname></term>
 589                                 <term><varname>LimitSTACK=</varname></term>
 590                                 <term><varname>LimitCORE=</varname></term>
 591                                 <term><varname>LimitRSS=</varname></term>
 592                                 <term><varname>LimitNOFILE=</varname></term>
 593                                 <term><varname>LimitAS=</varname></term>
 594                                 <term><varname>LimitNPROC=</varname></term>
 595                                 <term><varname>LimitMEMLOCK=</varname></term>
 596                                 <term><varname>LimitLOCKS=</varname></term>
 597                                 <term><varname>LimitSIGPENDING=</varname></term>
 598                                 <term><varname>LimitMSGQUEUE=</varname></term>
 599                                 <term><varname>LimitNICE=</varname></term>
 600                                 <term><varname>LimitRTPRIO=</varname></term>
 601                                 <term><varname>LimitRTTIME=</varname></term>
 602                                 <listitem><para>These settings control
 603                                 various resource limits for executed
 604                                 processes. See
 605                                 <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 606                                 for details. Use the string
 607                                 <varname>infinity</varname> to
 608                                 configure no limit on a specific
 609                                 resource.</para></listitem>
 610                         </varlistentry>
 611
 612                         <varlistentry>
 613                                 <term><varname>PAMName=</varname></term>
 614                                 <listitem><para>Sets the PAM service
 615                                 name to set up a session as. If set
 616                                 the executed process will be
 617                                 registered as a PAM session under the
 618                                 specified service name. This is only
 619                                 useful in conjunction with the
 620                                 <varname>User=</varname> setting. If
 621                                 not set no PAM session will be opened
 622                                 for the executed processes. See
 623                                 <citerefentry><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 624                                 for details.</para></listitem>
 625                         </varlistentry>
 626
 627                         <varlistentry>
 628                                 <term><varname>TCPWrapName=</varname></term>
 629                                 <listitem><para>If this is a
 630                                 socket-activated service this sets the
 631                                 tcpwrap service name to check the
 632                                 permission for the current connection
 633                                 with. This is only useful in
 634                                 conjunction with socket-activated
 635                                 services, and stream sockets (TCP) in
 636                                 particular. It has no effect on other
 637                                 socket types (e.g. datagram/UDP) and on processes
 638                                 unrelated to socket-based
 639                                 activation. If the tcpwrap
 640                                 verification fails daemon start-up
 641                                 will fail and the connection is
 642                                 terminated. See
 643                                 <citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 644                                 for details.</para></listitem>
 645                         </varlistentry>
 646
 647                         <varlistentry>
 648                                 <term><varname>CapabilityBoundingSet=</varname></term>
 649
 650                                 <listitem><para>Controls which
 651                                 capabilities to include in the
 652                                 capability bounding set for the
 653                                 executed process. See
 654                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 655                                 for details. Takes a whitespace
 656                                 separated list of capability names as
 657                                 read by
 658                                 <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 659                                 Capabilities listed will be included
 660                                 in the bounding set, all others are
 661                                 removed. If the list of capabilities
 662                                 is prefixed with ~ all but the listed
 663                                 capabilities will be included, the
 664                                 effect of the assignment
 665                                 inverted. Note that this option does
 666                                 not actually set or unset any
 667                                 capabilities in the effective,
 668                                 permitted or inherited capability
 669                                 sets. That's what
 670                                 <varname>Capabilities=</varname> is
 671                                 for. If this option is not used the
 672                                 capability bounding set is not
 673                                 modified on process execution, hence
 674                                 no limits on the capabilities of the
 675                                 process are enforced.</para></listitem>
 676                         </varlistentry>
 677
 678                         <varlistentry>
 679                                 <term><varname>SecureBits=</varname></term>
 680                                 <listitem><para>Controls the secure
 681                                 bits set for the executed process. See
 682                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 683                                 for details. Takes a list of strings:
 684                                 <option>keep-caps</option>,
 685                                 <option>keep-caps-locked</option>,
 686                                 <option>no-setuid-fixup</option>,
 687                                 <option>no-setuid-fixup-locked</option>,
 688                                 <option>noroot</option> and/or
 689                                 <option>noroot-locked</option>.
 690                                 </para></listitem>
 691                         </varlistentry>
 692
 693                         <varlistentry>
 694                                 <term><varname>Capabilities=</varname></term>
 695                                 <listitem><para>Controls the
 696                                 <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 697                                 set for the executed process. Take a
 698                                 capability string describing the
 699                                 effective, permitted and inherited
 700                                 capability sets as documented in
 701                                 <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 702                                 Note that these capability sets are
 703                                 usually influenced by the capabilities
 704                                 attached to the executed file. Due to
 705                                 that
 706                                 <varname>CapabilityBoundingSet=</varname>
 707                                 is probably the much more useful
 708                                 setting.</para></listitem>
 709                         </varlistentry>
 710
 711                         <varlistentry>
 712                                 <term><varname>ControlGroup=</varname></term>
 713
 714                                 <listitem><para>Controls the control
 715                                 groups the executed processes shall be
 716                                 made members of. Takes a
 717                                 space-separated list of cgroup
 718                                 identifiers. A cgroup identifier has a
 719                                 format like
 720                                 <filename>cpu:/foo/bar</filename>,
 721                                 where "cpu" identifies the kernel
 722                                 control group controller used, and
 723                                 <filename>/foo/bar</filename> is the
 724                                 control group path. The controller
 725                                 name and ":" may be omitted in which
 726                                 case the named systemd control group
 727                                 hierarchy is implied. Alternatively,
 728                                 the path and ":" may be omitted, in
 729                                 which case the default control group
 730                                 path for this unit is implied. This
 731                                 option may be used to place executed
 732                                 processes in arbitrary groups in
 733                                 arbitrary hierarchies -- which can be
 734                                 configured externally with additional
 735                                 execution limits. By default systemd
 736                                 will place all executed processes in
 737                                 separate per-unit control groups
 738                                 (named after the unit) in the systemd
 739                                 named hierarchy. Since every process
 740                                 can be in one group per hierarchy only
 741                                 overriding the control group path in
 742                                 the named systemd hierarchy will
 743                                 disable automatic placement in the
 744                                 default group. This option is
 745                                 primarily intended to place executed
 746                                 processes in specific paths in
 747                                 specific kernel controller
 748                                 hierarchies. It is however not
 749                                 recommended to manipulate the service
 750                                 control group path in the systemd
 751                                 named hierarchy. For details about
 752                                 control groups see <ulink
 753                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
 754                         </varlistentry>
 755
 756                         <varlistentry>
 757                                 <term><varname>ControlGroupModify=</varname></term>
 758                                 <listitem><para>Takes a boolean
 759                                 argument. If true, the control groups
 760                                 created for this unit will be owned by
 761                                 the user specified with
 762                                 <varname>User=</varname> (and the
 763                                 appropriate group), and he/she can create
 764                                 subgroups as well as add processes to
 765                                 the group.</para></listitem>
 766                         </varlistentry>
 767
 768                         <varlistentry>
 769                                 <term><varname>ControlGroupAttribute=</varname></term>
 770
 771                                 <listitem><para>Set a specific control
 772                                 group attribute for executed
 773                                 processes, and (if needed) add the the
 774                                 executed processes to a cgroup in the
 775                                 hierarchy of the controller the
 776                                 attribute belongs to. Takes two
 777                                 space-separated arguments: the
 778                                 attribute name (syntax is
 779                                 <literal>cpu.shares</literal> where
 780                                 <literal>cpu</literal> refers to a
 781                                 specific controller and
 782                                 <literal>shares</literal> to the
 783                                 attribute name), and the attribute
 784                                 value. Example:
 785                                 <literal>ControlGroupAttribute=cpu.shares
 786                                 512</literal>. If this option is used
 787                                 for an attribute that belongs to a
 788                                 kernel controller hierarchy the unit
 789                                 is not already configured to be added
 790                                 to (for example via the
 791                                 <literal>ControlGroup=</literal>
 792                                 option) then the unit will be added to
 793                                 the controller and the default unit
 794                                 cgroup path is implied. Thus, using
 795                                 <varname>ControlGroupAttribute=</varname>
 796                                 is in most case sufficient to make use
 797                                 of control group enforcements,
 798                                 explicit
 799                                 <varname>ControlGroup=</varname> are
 800                                 only necessary in case the implied
 801                                 default control group path for a
 802                                 service is not desirable. For details
 803                                 about control group attributes see
 804                                 <ulink
 805                                 url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>. This
 806                                 option may appear more than once, in
 807                                 order to set multiple control group
 808                                 attributes.</para></listitem>
 809                         </varlistentry>
 810
 811                         <varlistentry>
 812                                 <term><varname>CPUShares=</varname></term>
 813
 814                                 <listitem><para>Assign the specified
 815                                 overall CPU time shares to the
 816                                 processes executed. Takes an integer
 817                                 value. This controls the
 818                                 <literal>cpu.shares</literal> control
 819                                 group attribute, which defaults to
 820                                 1024. For details about this control
 821                                 group attribute see <ulink
 822                                 url="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para></listitem>
 823                         </varlistentry>
 824
 825                         <varlistentry>
 826                                 <term><varname>MemoryLimit=</varname></term>
 827                                 <term><varname>MemorySoftLimit=</varname></term>
 828
 829                                 <listitem><para>Limit the overall memory usage
 830                                 of the executed processes to a certain
 831                                 size. Takes a memory size in bytes. If
 832                                 the value is suffixed with K, M, G or
 833                                 T the specified memory size is parsed
 834                                 as Kilobytes, Megabytes, Gigabytes,
 835                                 resp. Terabytes (to the base
 836                                 1024). This controls the
 837                                 <literal>memory.limit_in_bytes</literal>
 838                                 and
 839                                 <literal>memory.soft_limit_in_bytes</literal>
 840                                 control group attributes. For details
 841                                 about these control group attributes
 842                                 see <ulink
 843                                 url="http://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para></listitem>
 844                         </varlistentry>
 845
 846                         <varlistentry>
 847                                 <term><varname>DeviceAllow=</varname></term>
 848                                 <term><varname>DeviceDeny=</varname></term>
 849
 850                                 <listitem><para>Control access to
 851                                 specific device nodes by the executed processes. Takes two
 852                                 space separated strings: a device node
 853                                 path (such as
 854                                 <filename>/dev/null</filename>)
 855                                 followed by a combination of r, w, m
 856                                 to control reading, writing resp.
 857                                 creating of the specific device node
 858                                 by the unit. This controls the
 859                                 <literal>devices.allow</literal>
 860                                 and
 861                                 <literal>devices.deny</literal>
 862                                 control group attributes. For details
 863                                 about these control group attributes
 864                                 see <ulink
 865                                 url="http://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para></listitem>
 866                         </varlistentry>
 867
 868                         <varlistentry>
 869                                 <term><varname>BlockIOWeight=</varname></term>
 870
 871                                 <listitem><para>Set the default or
 872                                 per-device overall block IO weight
 873                                 value for the executed
 874                                 processes. Takes either a single
 875                                 weight value (between 10 and 1000) to
 876                                 set the default block IO weight, or a
 877                                 space separated pair of a file path
 878                                 and a weight value to specify the
 879                                 device specific weight value (Example:
 880                                 "/dev/sda 500"). The file path may be
 881                                 specified as path to a block device
 882                                 node or as any other file in which
 883                                 case the backing block device of the
 884                                 file system of the file is
 885                                 determined. This controls the
 886                                 <literal>blkio.weight</literal> and
 887                                 <literal>blkio.weight_device</literal>
 888                                 control group attributes, which
 889                                 default to 1000. Use this option
 890                                 multiple times to set weights for
 891                                 multiple devices. For details about
 892                                 these control group attributes see
 893                                 <ulink
 894                                 url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
 895                         </varlistentry>
 896
 897                         <varlistentry>
 898                                 <term><varname>BlockIOReadBandwidth=</varname></term>
 899                                 <term><varname>BlockIOWriteBandwidth=</varname></term>
 900
 901                                 <listitem><para>Set the per-device
 902                                 overall block IO bandwith limit for
 903                                 the executed processes. Takes a space
 904                                 separated pair of a file path and a
 905                                 bandwith value (in bytes per second)
 906                                 to specify the device specific
 907                                 bandwidth. The file path may be
 908                                 specified as path to a block device
 909                                 node or as any other file in which
 910                                 case the backing block device of the
 911                                 file system of the file is determined.
 912                                 If the bandwith is suffixed with K, M,
 913                                 G, or T the specified bandwith is
 914                                 parsed as Kilobytes, Megabytes,
 915                                 Gigabytes, resp. Terabytes (Example:
 916                                 "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
 917                                 5M"). This controls the
 918                                 <literal>blkio.read_bps_device</literal>
 919                                 and
 920                                 <literal>blkio.write_bps_device</literal>
 921                                 control group attributes. Use this
 922                                 option multiple times to set bandwith
 923                                 limits for multiple devices. For
 924                                 details about these control group
 925                                 attributes see <ulink
 926                                 url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
 927                         </varlistentry>
 928
 929                         <varlistentry>
 930                                 <term><varname>ReadWriteDirectories=</varname></term>
 931                                 <term><varname>ReadOnlyDirectories=</varname></term>
 932                                 <term><varname>InaccessibleDirectories=</varname></term>
 933
 934                                 <listitem><para>Sets up a new
 935                                 file-system name space for executed
 936                                 processes. These options may be used
 937                                 to limit access a process might have
 938                                 to the main file-system
 939                                 hierarchy. Each setting takes a
 940                                 space-separated list of absolute
 941                                 directory paths. Directories listed in
 942                                 <varname>ReadWriteDirectories=</varname>
 943                                 are accessible from within the
 944                                 namespace with the same access rights
 945                                 as from outside. Directories listed in
 946                                 <varname>ReadOnlyDirectories=</varname>
 947                                 are accessible for reading only,
 948                                 writing will be refused even if the
 949                                 usual file access controls would
 950                                 permit this. Directories listed in
 951                                 <varname>InaccessibleDirectories=</varname>
 952                                 will be made inaccessible for processes
 953                                 inside the namespace. Note that
 954                                 restricting access with these options
 955                                 does not extend to submounts of a
 956                                 directory. You must list submounts
 957                                 separately in these settings to
 958                                 ensure the same limited access. These
 959                                 options may be specified more than
 960                                 once in which case all directories
 961                                 listed will have limited access from
 962                                 within the
 963                                 namespace.</para></listitem>
 964                         </varlistentry>
 965
 966                         <varlistentry>
 967                                 <term><varname>PrivateTmp=</varname></term>
 968
 969                                 <listitem><para>Takes a boolean
 970                                 argument. If true sets up a new file
 971                                 system namespace for the executed
 972                                 processes and mounts a private
 973                                 <filename>/tmp</filename> directory
 974                                 inside it, that is not shared by
 975                                 processes outside of the
 976                                 namespace. This is useful to secure
 977                                 access to temporary files of the
 978                                 process, but makes sharing between
 979                                 processes via
 980                                 <filename>/tmp</filename>
 981                                 impossible. Defaults to
 982                                 false.</para></listitem>
 983                         </varlistentry>
 984
 985                         <varlistentry>
 986                                 <term><varname>PrivateNetwork=</varname></term>
 987
 988                                 <listitem><para>Takes a boolean
 989                                 argument. If true sets up a new
 990                                 network namespace for the executed
 991                                 processes and configures only the
 992                                 loopback network device
 993                                 <literal>lo</literal> inside it. No
 994                                 other network devices will be
 995                                 available to the executed process.
 996                                 This is useful to securely turn off
 997                                 network access by the executed
 998                                 process. Defaults to
 999                                 false.</para></listitem>
1000                         </varlistentry>
1001
1002                         <varlistentry>
1003                                 <term><varname>MountFlags=</varname></term>
1004
1005                                 <listitem><para>Takes a mount
1006                                 propagation flag:
1007                                 <option>shared</option>,
1008                                 <option>slave</option> or
1009                                 <option>private</option>, which
1010                                 control whether namespaces set up with
1011                                 <varname>ReadWriteDirectories=</varname>,
1012                                 <varname>ReadOnlyDirectories=</varname>
1013                                 and
1014                                 <varname>InaccessibleDirectories=</varname>
1015                                 receive or propagate new mounts
1016                                 from/to the main namespace. See
1017                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
1018                                 for details. Defaults to
1019                                 <option>shared</option>, i.e. the new
1020                                 namespace will both receive new mount
1021                                 points from the main namespace as well
1022                                 as propagate new mounts to
1023                                 it.</para></listitem>
1024                         </varlistentry>
1025
1026                         <varlistentry>
1027                                 <term><varname>UtmpIdentifier=</varname></term>
1028
1029                                 <listitem><para>Takes a a four
1030                                 character identifier string for an
1031                                 utmp/wtmp entry for this service. This
1032                                 should only be set for services such
1033                                 as <command>getty</command>
1034                                 implementations where utmp/wtmp
1035                                 entries must be created and cleared
1036                                 before and after execution. If the
1037                                 configured string is longer than four
1038                                 characters it is truncated and the
1039                                 terminal four characters are
1040                                 used. This setting interprets %I style
1041                                 string replacements. This setting is
1042                                 unset by default, i.e. no utmp/wtmp
1043                                 entries are created or cleaned up for
1044                                 this service.</para></listitem>
1045                         </varlistentry>
1046
1047                 </variablelist>
1048         </refsect1>
1049
1050         <refsect1>
1051                   <title>See Also</title>
1052                   <para>
1053                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1054                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
1055                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1056                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1057                           <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1058                           <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1059                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
1060                   </para>
1061         </refsect1>
1062
1063 </refentry>