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<refentry id="systemd.exec">
- <refentryinfo>
- <title>systemd.exec</title>
- <productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
- </refentryinfo>
-
- <refmeta>
- <refentrytitle>systemd.exec</refentrytitle>
- <manvolnum>5</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>systemd.exec</refname>
- <refpurpose>Execution environment configuration</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <para><filename><replaceable>service</replaceable>.service</filename>,
- <filename><replaceable>socket</replaceable>.socket</filename>,
- <filename><replaceable>mount</replaceable>.mount</filename>,
- <filename><replaceable>swap</replaceable>.swap</filename></para>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para>Unit configuration files for services, sockets,
- mount points, and swap devices share a subset of
- configuration options which define the execution
- environment of spawned processes.</para>
-
- <para>This man page lists the configuration options
- shared by these four unit types. See
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for the common options of all unit configuration
- files, and
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- and
- <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for more information on the specific unit
- configuration files. The execution specific
- configuration options are configured in the [Service],
- [Socket], [Mount], or [Swap] sections, depending on the unit
- type.</para>
- </refsect1>
-
- <refsect1>
- <title>Options</title>
-
- <variablelist class='unit-directives'>
-
- <varlistentry>
- <term><varname>WorkingDirectory=</varname></term>
-
- <listitem><para>Takes an absolute
- directory path. Sets the working
- directory for executed processes. If
- not set, defaults to the root directory
- when systemd is running as a system
- instance and the respective user's
- home directory if run as
- user.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>RootDirectory=</varname></term>
-
- <listitem><para>Takes an absolute
- directory path. Sets the root
- directory for executed processes, with
- the
- <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- system call. If this is used, it must
- be ensured that the process and all
- its auxiliary files are available in
- the <function>chroot()</function>
- jail.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>User=</varname></term>
- <term><varname>Group=</varname></term>
-
- <listitem><para>Sets the Unix user
- or group that the processes are executed
- as, respectively. Takes a single user or group
- name or ID as argument. If no group is
- set, the default group of the user is
- chosen.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SupplementaryGroups=</varname></term>
-
- <listitem><para>Sets the supplementary
- Unix groups the processes are executed
- as. This takes a space-separated list
- of group names or IDs. This option may
- be specified more than once in which
- case all listed groups are set as
- supplementary groups. When the empty
- string is assigned the list of
- supplementary groups is reset, and all
- assignments prior to this one will
- have no effect. In any way, this
- option does not override, but extends
- the list of supplementary groups
- configured in the system group
- database for the
- user.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Nice=</varname></term>
-
- <listitem><para>Sets the default nice
- level (scheduling priority) for
- executed processes. Takes an integer
- between -20 (highest priority) and 19
- (lowest priority). See
- <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>OOMScoreAdjust=</varname></term>
-
- <listitem><para>Sets the adjustment
- level for the Out-Of-Memory killer for
- executed processes. Takes an integer
- between -1000 (to disable OOM killing
- for this process) and 1000 (to make
- killing of this process under memory
- pressure very likely). See <ulink
- url="https://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>IOSchedulingClass=</varname></term>
-
- <listitem><para>Sets the IO scheduling
- class for executed processes. Takes an
- integer between 0 and 3 or one of the
- strings <option>none</option>,
- <option>realtime</option>,
- <option>best-effort</option> or
- <option>idle</option>. See
- <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>IOSchedulingPriority=</varname></term>
-
- <listitem><para>Sets the IO scheduling
- priority for executed processes. Takes
- an integer between 0 (highest
- priority) and 7 (lowest priority). The
- available priorities depend on the
- selected IO scheduling class (see
- above). See
- <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUSchedulingPolicy=</varname></term>
-
- <listitem><para>Sets the CPU
- scheduling policy for executed
- processes. Takes one of
- <option>other</option>,
- <option>batch</option>,
- <option>idle</option>,
- <option>fifo</option> or
- <option>rr</option>. See
- <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUSchedulingPriority=</varname></term>
-
- <listitem><para>Sets the CPU
- scheduling priority for executed
- processes. The available priority
- range depends on the selected CPU
- scheduling policy (see above). For
- real-time scheduling policies an
- integer between 1 (lowest priority)
- and 99 (highest priority) can be used.
- See <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUSchedulingResetOnFork=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, elevated CPU
- scheduling priorities and policies
- will be reset when the executed
- processes fork, and can hence not leak
- into child processes. See
- <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details. Defaults to false.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUAffinity=</varname></term>
-
- <listitem><para>Controls the CPU
- affinity of the executed
- processes. Takes a space-separated
- list of CPU indices. This option may
- be specified more than once in which
- case the specified CPU affinity masks
- are merged. If the empty string is
- assigned, the mask is reset, all
- assignments prior to this will have no
- effect. See
- <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>UMask=</varname></term>
-
- <listitem><para>Controls the file mode
- creation mask. Takes an access mode in
- octal notation. See
- <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details. Defaults to
- 0022.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Environment=</varname></term>
-
- <listitem><para>Sets environment
- variables for executed
- processes. Takes a space-separated
- list of variable assignments. This
- option may be specified more than once
- in which case all listed variables
- will be set. If the same variable is
- set twice, the later setting will
- override the earlier setting. If the
- empty string is assigned to this
- option, the list of environment
- variables is reset, all prior
- assignments have no effect.
- Variable expansion is not performed
- inside the strings, however, specifier
- expansion is possible. The $ character has
- no special meaning.
- If you need to assign a value containing spaces
- to a variable, use double quotes (")
- for the assignment.</para>
-
- <para>Example:
- <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"</programlisting>
- gives three variables <literal>VAR1</literal>,
- <literal>VAR2</literal>, <literal>VAR3</literal>
- with the values <literal>word1 word2</literal>,
- <literal>word3</literal>, <literal>$word 5 6</literal>.
- </para>
-
- <para>
- See
- <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for details about environment variables.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>EnvironmentFile=</varname></term>
- <listitem><para>Similar to
- <varname>Environment=</varname> but
- reads the environment variables from a
- text file. The text file should
- contain new-line-separated variable
- assignments. Empty lines and lines
- starting with ; or # will be ignored,
- which may be used for commenting. A line
- ending with a backslash will be concatenated
- with the following one, allowing multiline variable
- definitions. The parser strips leading
- and trailing whitespace from the values
- of assignments, unless you use
- double quotes (").</para>
-
- <para>The argument passed should be an
- absolute filename or wildcard
- expression, optionally prefixed with
- <literal>-</literal>, which indicates
- that if the file does not exist, it
- will not be read and no error or warning
- message is logged. This option may be
- specified more than once in which case
- all specified files are read. If the
- empty string is assigned to this
- option, the list of file to read is
- reset, all prior assignments have no
- effect.</para>
-
- <para>The files listed with this
- directive will be read shortly before
- the process is executed (more
- specifically, after all
- processes from a previous unit state
- terminated. This means you can
- generate these files in one unit
- state, and read it with this option in
- the next). Settings from these files
- override settings made with
- <varname>Environment=</varname>. If
- the same variable is set twice from
- these files, the files will be read in
- the order they are specified and the
- later setting will override the
- earlier setting.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>StandardInput=</varname></term>
- <listitem><para>Controls where file
- descriptor 0 (STDIN) of the executed
- processes is connected to. Takes one
- of <option>null</option>,
- <option>tty</option>,
- <option>tty-force</option>,
- <option>tty-fail</option> or
- <option>socket</option>.</para>
-
- <para>If <option>null</option> is
- selected, standard input will be
- connected to
- <filename>/dev/null</filename>,
- i.e. all read attempts by the process
- will result in immediate EOF.</para>
-
- <para>If <option>tty</option> is
- selected, standard input is connected
- to a TTY (as configured by
- <varname>TTYPath=</varname>, see
- below) and the executed process
- becomes the controlling process of the
- terminal. If the terminal is already
- being controlled by another process,
- the executed process waits until the
- current controlling process releases
- the terminal.</para>
-
- <para><option>tty-force</option> is similar
- to <option>tty</option>, but the
- executed process is forcefully and
- immediately made the controlling
- process of the terminal, potentially
- removing previous controlling
- processes from the
- terminal.</para>
-
- <para><option>tty-fail</option> is
- similar to <option>tty</option> but if
- the terminal already has a controlling
- process start-up of the executed
- process fails.</para>
-
- <para>The <option>socket</option>
- option is only valid in
- socket-activated services, and only
- when the socket configuration file
- (see
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details) specifies a single socket
- only. If this option is set, standard
- input will be connected to the socket
- the service was activated from, which
- is primarily useful for compatibility
- with daemons designed for use with the
- traditional
- <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- daemon.</para>
-
- <para>This setting defaults to
- <option>null</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>StandardOutput=</varname></term>
- <listitem><para>Controls where file
- descriptor 1 (STDOUT) of the executed
- processes is connected to. Takes one
- of <option>inherit</option>,
- <option>null</option>,
- <option>tty</option>,
- <option>journal</option>,
- <option>syslog</option>,
- <option>kmsg</option>,
- <option>journal+console</option>,
- <option>syslog+console</option>,
- <option>kmsg+console</option> or
- <option>socket</option>.</para>
-
- <para><option>inherit</option>
- duplicates the file descriptor of
- standard input for standard
- output.</para>
-
- <para><option>null</option> connects
- standard output to
- <filename>/dev/null</filename>,
- i.e. everything written to it will be
- lost.</para>
-
- <para><option>tty</option> connects
- standard output to a tty (as
- configured via
- <varname>TTYPath=</varname>, see
- below). If the TTY is used for output
- only, the executed process will not
- become the controlling process of the
- terminal, and will not fail or wait
- for other processes to release the
- terminal.</para>
-
- <para><option>journal</option>
- connects standard output with the
- journal which is accessible via
- <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
- Note that everything that is written
- to syslog or kmsg (see below) is
- implicitly stored in the journal as
- well, the specific two options listed
- below are hence supersets of this
- one.</para>
-
- <para><option>syslog</option> connects
- standard output to the <citerefentry
- project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- system syslog service, in addition to
- the journal. Note that the journal
- daemon is usually configured to
- forward everything it receives to
- syslog anyway, in which case this
- option is no different from
- <option>journal</option>.</para>
-
- <para><option>kmsg</option> connects
- standard output with the kernel log
- buffer which is accessible via
- <citerefentry
- project='man-pages'><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- in addition to the journal. The
- journal daemon might be configured to
- send all logs to kmsg anyway, in which
- case this option is no different from
- <option>journal</option>.</para>
-
- <para><option>journal+console</option>,
- <option>syslog+console</option> and
- <option>kmsg+console</option> work in
- a similar way as the three options
- above but copy the output to the
- system console as well.</para>
-
- <para><option>socket</option> connects
- standard output to a socket acquired
- via socket activation. The semantics
- are similar to the same option of
- <varname>StandardInput=</varname>.</para>
-
- <para>This setting defaults to the
- value set with
- <option>DefaultStandardOutput=</option>
- in
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- which defaults to
- <option>journal</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>StandardError=</varname></term>
- <listitem><para>Controls where file
- descriptor 2 (STDERR) of the
- executed processes is connected to.
- The available options are identical to
- those of
- <varname>StandardOutput=</varname>,
- with one exception: if set to
- <option>inherit</option> the file
- descriptor used for standard output is
- duplicated for standard error. This
- setting defaults to the value set with
- <option>DefaultStandardError=</option>
- in
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- which defaults to
- <option>inherit</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>TTYPath=</varname></term>
- <listitem><para>Sets the terminal
- device node to use if standard input, output,
- or error are connected to a
- TTY (see above). Defaults to
- <filename>/dev/console</filename>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>TTYReset=</varname></term>
- <listitem><para>Reset the terminal
- device specified with
- <varname>TTYPath=</varname> before and
- after execution. Defaults to
- <literal>no</literal>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>TTYVHangup=</varname></term>
- <listitem><para>Disconnect all clients
- which have opened the terminal device
- specified with
- <varname>TTYPath=</varname>
- before and after execution. Defaults
- to
- <literal>no</literal>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>TTYVTDisallocate=</varname></term>
- <listitem><para>If the terminal
- device specified with
- <varname>TTYPath=</varname> is a
- virtual console terminal, try to
- deallocate the TTY before and after
- execution. This ensures that the
- screen and scrollback buffer is
- cleared. Defaults to
- <literal>no</literal>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>SyslogIdentifier=</varname></term>
- <listitem><para>Sets the process name
- to prefix log lines sent to the
- logging system or the kernel log
- buffer with. If not set, defaults to
- the process name of the executed
- process. This option is only useful
- when
- <varname>StandardOutput=</varname> or
- <varname>StandardError=</varname> are
- set to <option>syslog</option>,
- <option>journal</option> or
- <option>kmsg</option> (or to the same
- settings in combination with
- <option>+console</option>).</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>SyslogFacility=</varname></term>
- <listitem><para>Sets the syslog
- facility to use when logging to
- syslog. One of <option>kern</option>,
- <option>user</option>,
- <option>mail</option>,
- <option>daemon</option>,
- <option>auth</option>,
- <option>syslog</option>,
- <option>lpr</option>,
- <option>news</option>,
- <option>uucp</option>,
- <option>cron</option>,
- <option>authpriv</option>,
- <option>ftp</option>,
- <option>local0</option>,
- <option>local1</option>,
- <option>local2</option>,
- <option>local3</option>,
- <option>local4</option>,
- <option>local5</option>,
- <option>local6</option> or
- <option>local7</option>. See
- <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for details. This option is only
- useful when
- <varname>StandardOutput=</varname> or
- <varname>StandardError=</varname> are
- set to <option>syslog</option>.
- Defaults to
- <option>daemon</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><varname>SyslogLevel=</varname></term>
- <listitem><para>Default syslog level
- to use when logging to syslog or the
- kernel log buffer. One of
- <option>emerg</option>,
- <option>alert</option>,
- <option>crit</option>,
- <option>err</option>,
- <option>warning</option>,
- <option>notice</option>,
- <option>info</option>,
- <option>debug</option>. See
- <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for details. This option is only
- useful when
- <varname>StandardOutput=</varname> or
- <varname>StandardError=</varname> are
- set to <option>syslog</option> or
- <option>kmsg</option>. Note that
- individual lines output by the daemon
- might be prefixed with a different log
- level which can be used to override
- the default log level specified
- here. The interpretation of these
- prefixes may be disabled with
- <varname>SyslogLevelPrefix=</varname>,
- see below. For details see
- <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
-
- Defaults to
- <option>info</option>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SyslogLevelPrefix=</varname></term>
- <listitem><para>Takes a boolean
- argument. If true and
- <varname>StandardOutput=</varname> or
- <varname>StandardError=</varname> are
- set to <option>syslog</option>,
- <option>kmsg</option> or
- <option>journal</option>, log lines
- written by the executed process that
- are prefixed with a log level will be
- passed on to syslog with this log
- level set but the prefix removed. If
- set to false, the interpretation of
- these prefixes is disabled and the
- logged lines are passed on as-is. For
- details about this prefixing see
- <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- Defaults to true.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>TimerSlackNSec=</varname></term>
- <listitem><para>Sets the timer slack
- in nanoseconds for the executed
- processes. The timer slack controls
- the accuracy of wake-ups triggered by
- timers. See
- <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for more information. Note that in
- contrast to most other time span
- definitions this parameter takes an
- integer value in nano-seconds if no
- unit is specified. The usual time
- units are understood
- too.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>LimitCPU=</varname></term>
- <term><varname>LimitFSIZE=</varname></term>
- <term><varname>LimitDATA=</varname></term>
- <term><varname>LimitSTACK=</varname></term>
- <term><varname>LimitCORE=</varname></term>
- <term><varname>LimitRSS=</varname></term>
- <term><varname>LimitNOFILE=</varname></term>
- <term><varname>LimitAS=</varname></term>
- <term><varname>LimitNPROC=</varname></term>
- <term><varname>LimitMEMLOCK=</varname></term>
- <term><varname>LimitLOCKS=</varname></term>
- <term><varname>LimitSIGPENDING=</varname></term>
- <term><varname>LimitMSGQUEUE=</varname></term>
- <term><varname>LimitNICE=</varname></term>
- <term><varname>LimitRTPRIO=</varname></term>
- <term><varname>LimitRTTIME=</varname></term>
- <listitem><para>These settings set both
- soft and hard limits of various resources for
- executed processes. See
- <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details. Use the string
- <varname>infinity</varname> to
- configure no limit on a specific
- resource.</para></listitem>
-
- <table>
- <title>Limit directives and their equivalent with ulimit</title>
-
- <tgroup cols='2'>
- <colspec colname='directive' />
- <colspec colname='equivalent' />
- <thead>
- <row>
- <entry>Directive</entry>
- <entry>ulimit equivalent</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>LimitCPU</entry>
- <entry>ulimit -t</entry>
- </row>
- <row>
- <entry>LimitFSIZE</entry>
- <entry>ulimit -f</entry>
- </row>
- <row>
- <entry>LimitDATA</entry>
- <entry>ulimit -d</entry>
- </row>
- <row>
- <entry>LimitSTACK</entry>
- <entry>ulimit -s</entry>
- </row>
- <row>
- <entry>LimitCORE</entry>
- <entry>ulimit -c</entry>
- </row>
- <row>
- <entry>LimitRSS</entry>
- <entry>ulimit -m</entry>
- </row>
- <row>
- <entry>LimitNOFILE</entry>
- <entry>ulimit -n</entry>
- </row>
- <row>
- <entry>LimitAS</entry>
- <entry>ulimit -v</entry>
- </row>
- <row>
- <entry>LimitNPROC</entry>
- <entry>ulimit -u</entry>
- </row>
- <row>
- <entry>LimitMEMLOCK</entry>
- <entry>ulimit -l</entry>
- </row>
- <row>
- <entry>LimitLOCKS</entry>
- <entry>ulimit -x</entry>
- </row>
- <row>
- <entry>LimitSIGPENDING</entry>
- <entry>ulimit -i</entry>
- </row>
- <row>
- <entry>LimitMSGQUEUE</entry>
- <entry>ulimit -q</entry>
- </row>
- <row>
- <entry>LimitNICE</entry>
- <entry>ulimit -e</entry>
- </row>
- <row>
- <entry>LimitRTPRIO</entry>
- <entry>ulimit -r</entry>
- </row>
- <row>
- <entry>LimitRTTIME</entry>
- <entry>No equivalent</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </varlistentry>
-
- <varlistentry>
- <term><varname>PAMName=</varname></term>
- <listitem><para>Sets the PAM service
- name to set up a session as. If set,
- the executed process will be
- registered as a PAM session under the
- specified service name. This is only
- useful in conjunction with the
- <varname>User=</varname> setting. If
- not set, no PAM session will be opened
- for the executed processes. See
- <citerefentry project='man-pages'><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CapabilityBoundingSet=</varname></term>
-
- <listitem><para>Controls which
- capabilities to include in the
- capability bounding set for the
- executed process. See
- <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for details. Takes a whitespace-separated
- list of capability names as read by
- <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- e.g. <constant>CAP_SYS_ADMIN</constant>,
- <constant>CAP_DAC_OVERRIDE</constant>,
- <constant>CAP_SYS_PTRACE</constant>.
- Capabilities listed will be included
- in the bounding set, all others are
- removed. If the list of capabilities
- is prefixed with <literal>~</literal>,
- all but the listed capabilities will
- be included, the effect of the
- assignment inverted. Note that this
- option also affects the respective
- capabilities in the effective,
- permitted and inheritable capability
- sets, on top of what
- <varname>Capabilities=</varname>
- does. If this option is not used, the
- capability bounding set is not
- modified on process execution, hence
- no limits on the capabilities of the
- process are enforced. This option may
- appear more than once in which case
- the bounding sets are merged. If the
- empty string is assigned to this
- option, the bounding set is reset to
- the empty capability set, and all
- prior settings have no effect. If set
- to <literal>~</literal> (without any
- further argument), the bounding set is
- reset to the full set of available
- capabilities, also undoing any
- previous settings.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SecureBits=</varname></term>
- <listitem><para>Controls the secure
- bits set for the executed process.
- Takes a space-separated combination of
- options from the following list:
- <option>keep-caps</option>,
- <option>keep-caps-locked</option>,
- <option>no-setuid-fixup</option>,
- <option>no-setuid-fixup-locked</option>,
- <option>noroot</option>, and
- <option>noroot-locked</option>. This
- option may appear more than once in
- which case the secure bits are ORed.
- If the empty string is assigned to
- this option, the bits are reset to 0.
- See <citerefentry
- project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Capabilities=</varname></term>
- <listitem><para>Controls the
- <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- set for the executed process. Take a
- capability string describing the
- effective, permitted and inherited
- capability sets as documented in
- <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- Note that these capability sets are
- usually influenced (and filtered) by the capabilities
- attached to the executed file. Due to
- that
- <varname>CapabilityBoundingSet=</varname>
- is probably a much more useful
- setting.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>ReadWriteDirectories=</varname></term>
- <term><varname>ReadOnlyDirectories=</varname></term>
- <term><varname>InaccessibleDirectories=</varname></term>
-
- <listitem><para>Sets up a new file
- system namespace for executed
- processes. These options may be used
- to limit access a process might have
- to the main file system
- hierarchy. Each setting takes a
- space-separated list of absolute
- directory paths. Directories listed in
- <varname>ReadWriteDirectories=</varname>
- are accessible from within the
- namespace with the same access rights
- as from outside. Directories listed in
- <varname>ReadOnlyDirectories=</varname>
- are accessible for reading only,
- writing will be refused even if the
- usual file access controls would
- permit this. Directories listed in
- <varname>InaccessibleDirectories=</varname>
- will be made inaccessible for
- processes inside the namespace. Note
- that restricting access with these
- options does not extend to submounts
- of a directory that are created later
- on. These options may be specified
- more than once in which case all
- directories listed will have limited
- access from within the namespace. If
- the empty string is assigned to this
- option, the specific list is reset,
- and all prior assignments have no
- effect.</para>
- <para>Paths in
- <varname>ReadOnlyDirectories=</varname>
- and
- <varname>InaccessibleDirectories=</varname>
- may be prefixed with
- <literal>-</literal>, in which case
- they will be ignored when they do not
- exist. Note that using this
- setting will disconnect propagation of
- mounts from the service to the host
- (propagation in the opposite direction
- continues to work). This means that
- this setting may not be used for
- services which shall be able to
- install mount points in the main mount
- namespace.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>PrivateTmp=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, sets up a new file
- system namespace for the executed
- processes and mounts private
- <filename>/tmp</filename> and
- <filename>/var/tmp</filename>
- directories inside it that is not
- shared by processes outside of the
- namespace. This is useful to secure
- access to temporary files of the
- process, but makes sharing between
- processes via
- <filename>/tmp</filename> or
- <filename>/var/tmp</filename>
- impossible. If this is enabled, all
- temporary files created by a service
- in these directories will be removed
- after the service is stopped. Defaults
- to false. It is possible to run two or
- more units within the same private
- <filename>/tmp</filename> and
- <filename>/var/tmp</filename>
- namespace by using the
- <varname>JoinsNamespaceOf=</varname>
- directive, see
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details. Note that using this
- setting will disconnect propagation of
- mounts from the service to the host
- (propagation in the opposite direction
- continues to work). This means that
- this setting may not be used for
- services which shall be able to install
- mount points in the main mount
- namespace.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>PrivateDevices=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, sets up a new /dev
- namespace for the executed processes
- and only adds API pseudo devices such
- as <filename>/dev/null</filename>,
- <filename>/dev/zero</filename> or
- <filename>/dev/random</filename> (as
- well as the pseudo TTY subsystem) to
- it, but no physical devices such as
- <filename>/dev/sda</filename>. This is
- useful to securely turn off physical
- device access by the executed
- process. Defaults to false. Enabling
- this option will also remove
- <constant>CAP_MKNOD</constant> from
- the capability bounding set for the
- unit (see above), and set
- <varname>DevicePolicy=closed</varname>
- (see
- <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details). Note that using this
- setting will disconnect propagation of
- mounts from the service to the host
- (propagation in the opposite direction
- continues to work). This means that
- this setting may not be used for
- services which shall be able to
- install mount points in the main mount
- namespace.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>PrivateNetwork=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, sets up a new
- network namespace for the executed
- processes and configures only the
- loopback network device
- <literal>lo</literal> inside it. No
- other network devices will be
- available to the executed process.
- This is useful to securely turn off
- network access by the executed
- process. Defaults to false. It is
- possible to run two or more units
- within the same private network
- namespace by using the
- <varname>JoinsNamespaceOf=</varname>
- directive, see
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details. Note that this option
- will disconnect all socket families
- from the host, this includes
- AF_NETLINK and AF_UNIX. The latter has
- the effect that AF_UNIX sockets in the
- abstract socket namespace will become
- unavailable to the processes (however,
- those located in the file system will
- continue to be
- accessible).</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>ProtectSystem=</varname></term>
-
- <listitem><para>Takes a boolean
- argument or
- <literal>full</literal>. If true,
- mounts the <filename>/usr</filename>
- and <filename>/boot</filename>
- directories read-only for processes
- invoked by this unit. If set to
- <literal>full</literal>, the
- <filename>/etc</filename> directory is
- mounted read-only, too. This setting
- ensures that any modification of the
- vendor supplied operating system (and
- optionally its configuration) is
- prohibited for the service. It is
- recommended to enable this setting for
- all long-running services, unless they
- are involved with system updates or
- need to modify the operating system in
- other ways. Note however that
- processes retaining the CAP_SYS_ADMIN
- capability can undo the effect of this
- setting. This setting is hence
- particularly useful for daemons which
- have this capability removed, for
- example with
- <varname>CapabilityBoundingSet=</varname>. Defaults
- to off.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>ProtectHome=</varname></term>
-
- <listitem><para>Takes a boolean
- argument or
- <literal>read-only</literal>. If true,
- the directories
- <filename>/home</filename> and
- <filename>/run/user</filename> are
- made inaccessible and empty for
- processes invoked by this unit. If set
- to <literal>read-only</literal>, the
- two directories are made read-only
- instead. It is recommended to enable
- this setting for all long-running
- services (in particular network-facing
- ones), to ensure they cannot get access
- to private user data, unless the
- services actually require access to
- the user's private data. Note however
- that processes retaining the
- CAP_SYS_ADMIN capability can undo the
- effect of this setting. This setting
- is hence particularly useful for
- daemons which have this capability
- removed, for example with
- <varname>CapabilityBoundingSet=</varname>. Defaults
- to off.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>MountFlags=</varname></term>
-
- <listitem><para>Takes a mount
- propagation flag:
- <option>shared</option>,
- <option>slave</option> or
- <option>private</option>, which
- control whether mounts in the file
- system namespace set up for this
- unit's processes will receive or
- propagate mounts or unmounts. See
- <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details. Defaults to
- <option>shared</option>. Use
- <option>shared</option> to ensure that
- mounts and unmounts are propagated
- from the host to the container and
- vice versa. Use <option>slave</option>
- to run processes so that none of their
- mounts and unmounts will propagate to
- the host. Use <option>private</option>
- to also ensure that no mounts and
- unmounts from the host will propagate
- into the unit processes'
- namespace. Note that
- <option>slave</option> means that file
- systems mounted on the host might stay
- mounted continuously in the unit's
- namespace, and thus keep the device
- busy. Note that the file system
- namespace related options
- (<varname>PrivateTmp=</varname>,
- <varname>PrivateDevices=</varname>,
- <varname>ProtectSystem=</varname>,
- <varname>ProtectHome=</varname>,
- <varname>ReadOnlyDirectories=</varname>,
- <varname>InaccessibleDirectories=</varname>
- and
- <varname>ReadWriteDirectories=</varname>)
- require that mount and unmount
- propagation from the unit's file
- system namespace is disabled, and
- hence downgrade
- <option>shared</option> to
- <option>slave</option>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>UtmpIdentifier=</varname></term>
-
- <listitem><para>Takes a four
- character identifier string for an
- utmp/wtmp entry for this service. This
- should only be set for services such
- as <command>getty</command>
- implementations where utmp/wtmp
- entries must be created and cleared
- before and after execution. If the
- configured string is longer than four
- characters, it is truncated and the
- terminal four characters are
- used. This setting interprets %I style
- string replacements. This setting is
- unset by default, i.e. no utmp/wtmp
- entries are created or cleaned up for
- this service.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SELinuxContext=</varname></term>
-
- <listitem><para>Set the SELinux
- security context of the executed
- process. If set, this will override
- the automated domain
- transition. However, the policy still
- needs to authorize the transition. This
- directive is ignored if SELinux is
- disabled. If prefixed by
- <literal>-</literal>, all errors will
- be ignored. See
- <citerefentry><refentrytitle>setexeccon</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for details.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>AppArmorProfile=</varname></term>
-
- <listitem><para>Takes a profile name as argument.
- The process executed by the unit will switch to
- this profile when started. Profiles must already
- be loaded in the kernel, or the unit will fail.
- This result in a non operation if AppArmor is not
- enabled. If prefixed by <literal>-</literal>, all errors
- will be ignored.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SmackProcessLabel=</varname></term>
-
- <listitem><para>Takes a
- <option>SMACK64</option> security
- label as argument. The process
- executed by the unit will be started
- under this label and SMACK will decide
- whether the processes is allowed to
- run or not based on it. The process
- will continue to run under the label
- specified here unless the executable
- has its own
- <option>SMACK64EXEC</option> label, in
- which case the process will transition
- to run under that label. When not
- specified, the label that systemd is
- running under is used. This directive
- is ignored if SMACK is
- disabled.</para>
-
- <para>The value may be prefixed by
- <literal>-</literal>, in which case
- all errors will be ignored. An empty
- value may be specified to unset
- previous assignments.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>IgnoreSIGPIPE=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, causes <constant>SIGPIPE</constant> to be
- ignored in the executed
- process. Defaults to true because
- <constant>SIGPIPE</constant> generally is useful only in
- shell pipelines.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>NoNewPrivileges=</varname></term>
-
- <listitem><para>Takes a boolean
- argument. If true, ensures that the
- service process and all its children
- can never gain new privileges. This
- option is more powerful than the respective
- secure bits flags (see above), as it
- also prohibits UID changes of any
- kind. This is the simplest, most
- effective way to ensure that a process
- and its children can never elevate
- privileges again.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SystemCallFilter=</varname></term>
-
- <listitem><para>Takes a
- space-separated list of system call
- names. If this setting is used, all
- system calls executed by the unit
- processes except for the listed ones
- will result in immediate process
- termination with the
- <constant>SIGSYS</constant> signal
- (whitelisting). If the first character
- of the list is <literal>~</literal>,
- the effect is inverted: only the
- listed system calls will result in
- immediate process termination
- (blacklisting). If running in user
- mode and this option is used,
- <varname>NoNewPrivileges=yes</varname>
- is implied. This feature makes use of the
- Secure Computing Mode 2 interfaces of
- the kernel ('seccomp filtering') and
- is useful for enforcing a minimal
- sandboxing environment. Note that the
- <function>execve</function>,
- <function>rt_sigreturn</function>,
- <function>sigreturn</function>,
- <function>exit_group</function>,
- <function>exit</function> system calls
- are implicitly whitelisted and do not
- need to be listed explicitly. This
- option may be specified more than once
- in which case the filter masks are
- merged. If the empty string is
- assigned, the filter is reset, all
- prior assignments will have no
- effect.</para>
-
- <para>If you specify both types of
- this option (i.e. whitelisting and
- blacklisting), the first encountered
- will take precedence and will dictate
- the default action (termination or
- approval of a system call). Then the
- next occurrences of this option will
- add or delete the listed system calls
- from the set of the filtered system
- calls, depending of its type and the
- default action. (For example, if you have started
- with a whitelisting of
- <function>read</function> and
- <function>write</function>, and right
- after it add a blacklisting of
- <function>write</function>, then
- <function>write</function> will be
- removed from the set.)
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SystemCallErrorNumber=</varname></term>
-
- <listitem><para>Takes an
- <literal>errno</literal> error number
- name to return when the system call
- filter configured with
- <varname>SystemCallFilter=</varname>
- is triggered, instead of terminating
- the process immediately. Takes an
- error name such as
- <constant>EPERM</constant>,
- <constant>EACCES</constant> or
- <constant>EUCLEAN</constant>. When this
- setting is not used, or when the empty
- string is assigned, the process will be
- terminated immediately when the filter
- is triggered.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>SystemCallArchitectures=</varname></term>
-
- <listitem><para>Takes a space
- separated list of architecture
- identifiers to include in the system
- call filter. The known architecture
- identifiers are
- <constant>x86</constant>,
- <constant>x86-64</constant>,
- <constant>x32</constant>,
- <constant>arm</constant> as well as
- the special identifier
- <constant>native</constant>. Only
- system calls of the specified
- architectures will be permitted to
- processes of this unit. This is an
- effective way to disable compatibility
- with non-native architectures for
- processes, for example to prohibit
- execution of 32-bit x86 binaries on
- 64-bit x86-64 systems. The special
- <constant>native</constant> identifier
- implicitly maps to the native
- architecture of the system (or more
- strictly: to the architecture the
- system manager is compiled for). If
- running in user mode and this option
- is used,
- <varname>NoNewPrivileges=yes</varname>
- is implied. Note that setting this
- option to a non-empty list implies
- that <constant>native</constant> is
- included too. By default, this option
- is set to the empty list, i.e. no
- architecture system call filtering is
- applied.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>RestrictAddressFamilies=</varname></term>
-
- <listitem><para>Restricts the set of
- socket address families accessible to
- the processes of this unit. Takes a
- space-separated list of address family
- names to whitelist, such as
- <constant>AF_UNIX</constant>,
- <constant>AF_INET</constant> or
- <constant>AF_INET6</constant>. When
- prefixed with <constant>~</constant>
- the listed address families will be
- applied as blacklist, otherwise as
- whitelist. Note that this restricts
- access to the
- <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- system call only. Sockets passed into
- the process by other means (for
- example, by using socket activation
- with socket units, see
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
- are unaffected. Also, sockets created
- with <function>socketpair()</function>
- (which creates connected AF_UNIX
- sockets only) are unaffected. Note
- that this option has no effect on
- 32-bit x86 and is ignored (but works
- correctly on x86-64). If running in user
- mode and this option is used,
- <varname>NoNewPrivileges=yes</varname>
- is implied. By default, no
- restriction applies, all address
- families are accessible to
- processes. If assigned the empty
- string, any previous list changes are
- undone.</para>
-
- <para>Use this option to limit
- exposure of processes to remote
- systems, in particular via exotic
- network protocols. Note that in most
- cases, the local
- <constant>AF_UNIX</constant> address
- family should be included in the
- configured whitelist as it is
- frequently used for local
- communication, including for
- <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- logging.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>Personality=</varname></term>
-
- <listitem><para>Controls which
- kernel architecture
- <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- shall report, when invoked by unit
- processes. Takes one of
- <constant>x86</constant> and
- <constant>x86-64</constant>. This is
- useful when running 32-bit services on
- a 64-bit host system. If not specified,
- the personality is left unmodified and
- thus reflects the personality of the
- host system's
- kernel.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>RuntimeDirectory=</varname></term>
- <term><varname>RuntimeDirectoryMode=</varname></term>
-
- <listitem><para>Takes a list of
- directory names. If set, one or more
- directories by the specified names
- will be created below
- <filename>/run</filename> (for system
- services) or below
- <varname>$XDG_RUNTIME_DIR</varname>
- (for user services) when the unit is
- started, and removed when the unit is
- stopped. The directories will have the
- access mode specified in
- <varname>RuntimeDirectoryMode=</varname>,
- and will be owned by the user and
- group specified in
- <varname>User=</varname> and
- <varname>Group=</varname>. Use this to
- manage one or more runtime directories
- of the unit and bind their lifetime to
- the daemon runtime. The specified
- directory names must be relative, and
- may not include a
- <literal>/</literal>, i.e. must refer
- to simple directories to create or
- remove. This is particularly useful
- for unprivileged daemons that cannot
- create runtime directories in
- <filename>/run</filename> due to lack
- of privileges, and to make sure the
- runtime directory is cleaned up
- automatically after use. For runtime
- directories that require more complex
- or different configuration or lifetime
- guarantees, please consider using
- <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
- </varlistentry>
-
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>Environment variables in spawned processes</title>
-
- <para>Processes started by the system are executed in
- a clean environment in which select variables
- listed below are set. System processes started by systemd
- do not inherit variables from PID 1, but processes
- started by user systemd instances inherit all
- environment variables from the user systemd instance.
- </para>
-
- <variablelist class='environment-variables'>
- <varlistentry>
- <term><varname>$PATH</varname></term>
-
- <listitem><para>Colon-separated list
- of directories to use when launching
- executables. Systemd uses a fixed
- value of
- <filename>/usr/local/sbin</filename>:<filename>/usr/local/bin</filename>:<filename>/usr/sbin</filename>:<filename>/usr/bin</filename>:<filename>/sbin</filename>:<filename>/bin</filename>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$LANG</varname></term>
-
- <listitem><para>Locale. Can be set in
- <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- or on the kernel command line (see
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- and
- <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>).
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$USER</varname></term>
- <term><varname>$LOGNAME</varname></term>
- <term><varname>$HOME</varname></term>
- <term><varname>$SHELL</varname></term>
-
- <listitem><para>User name (twice), home
- directory, and the login shell.
- The variables are set for the units that
- have <varname>User=</varname> set,
- which includes user
- <command>systemd</command> instances.
- See
- <citerefentry><refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$XDG_RUNTIME_DIR</varname></term>
-
- <listitem><para>The directory for volatile
- state. Set for the user <command>systemd</command>
- instance, and also in user sessions.
- See
- <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$XDG_SESSION_ID</varname></term>
- <term><varname>$XDG_SEAT</varname></term>
- <term><varname>$XDG_VTNR</varname></term>
-
- <listitem><para>The identifier of the
- session, the seat name, and
- virtual terminal of the session. Set
- by
- <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- for login sessions.
- <varname>$XDG_SEAT</varname> and
- <varname>$XDG_VTNR</varname> will
- only be set when attached to a seat and a
- tty.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$MAINPID</varname></term>
-
- <listitem><para>The PID of the units
- main process if it is known. This is
- only set for control processes as
- invoked by
- <varname>ExecReload=</varname> and
- similar. </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$MANAGERPID</varname></term>
-
- <listitem><para>The PID of the user
- <command>systemd</command> instance,
- set for processes spawned by it.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$LISTEN_FDS</varname></term>
- <term><varname>$LISTEN_PID</varname></term>
-
- <listitem><para>Information about file
- descriptors passed to a service for
- socket activation. See
- <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- </para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>$TERM</varname></term>
-
- <listitem><para>Terminal type, set
- only for units connected to a terminal
- (<varname>StandardInput=tty</varname>,
- <varname>StandardOutput=tty</varname>,
- or
- <varname>StandardError=tty</varname>).
- See
- <citerefentry project='man-pages'><refentrytitle>termcap</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
- </para></listitem>
- </varlistentry>
- </variablelist>
-
- <para>Additional variables may be configured by the
- following means: for processes spawned in specific
- units, use the <varname>Environment=</varname> and
- <varname>EnvironmentFile=</varname> options above; to
- specify variables globally, use
- <varname>DefaultEnvironment=</varname> (see
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
- or the kernel option
- <varname>systemd.setenv=</varname> (see
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>). Additional
- variables may also be set through PAM,
- cf. <citerefentry project='man-pages'><refentrytitle>pam_env</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
- </refsect1>
-
- <refsect1>
- <title>See Also</title>
- <para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>exec</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- </para>
- </refsect1>
+ <refentryinfo>
+ <title>systemd.exec</title>
+ <productname>systemd</productname>
+
+ <authorgroup>
+ <author>
+ <contrib>Developer</contrib>
+ <firstname>Lennart</firstname>
+ <surname>Poettering</surname>
+ <email>lennart@poettering.net</email>
+ </author>
+ </authorgroup>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>systemd.exec</refentrytitle>
+ <manvolnum>5</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>systemd.exec</refname>
+ <refpurpose>Execution environment configuration</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <para><filename><replaceable>service</replaceable>.service</filename>,
+ <filename><replaceable>socket</replaceable>.socket</filename>,
+ <filename><replaceable>mount</replaceable>.mount</filename>,
+ <filename><replaceable>swap</replaceable>.swap</filename></para>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para>Unit configuration files for services, sockets, mount
+ points, and swap devices share a subset of configuration options
+ which define the execution environment of spawned
+ processes.</para>
+
+ <para>This man page lists the configuration options shared by
+ these four unit types. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for the common options of all unit configuration files, and
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ and
+ <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for more information on the specific unit configuration files. The
+ execution specific configuration options are configured in the
+ [Service], [Socket], [Mount], or [Swap] sections, depending on the
+ unit type.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Options</title>
+
+ <variablelist class='unit-directives'>
+
+ <varlistentry>
+ <term><varname>WorkingDirectory=</varname></term>
+
+ <listitem><para>Takes an absolute directory path. Sets the
+ working directory for executed processes. If not set, defaults
+ to the root directory when systemd is running as a system
+ instance and the respective user's home directory if run as
+ user.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RootDirectory=</varname></term>
+
+ <listitem><para>Takes an absolute directory path. Sets the
+ root directory for executed processes, with the
+ <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ system call. If this is used, it must be ensured that the
+ process and all its auxiliary files are available in the
+ <function>chroot()</function> jail.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>User=</varname></term>
+ <term><varname>Group=</varname></term>
+
+ <listitem><para>Sets the Unix user or group that the processes
+ are executed as, respectively. Takes a single user or group
+ name or ID as argument. If no group is set, the default group
+ of the user is chosen.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SupplementaryGroups=</varname></term>
+
+ <listitem><para>Sets the supplementary Unix groups the
+ processes are executed as. This takes a space-separated list
+ of group names or IDs. This option may be specified more than
+ once in which case all listed groups are set as supplementary
+ groups. When the empty string is assigned the list of
+ supplementary groups is reset, and all assignments prior to
+ this one will have no effect. In any way, this option does not
+ override, but extends the list of supplementary groups
+ configured in the system group database for the
+ user.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Nice=</varname></term>
+
+ <listitem><para>Sets the default nice level (scheduling
+ priority) for executed processes. Takes an integer between -20
+ (highest priority) and 19 (lowest priority). See
+ <citerefentry><refentrytitle>setpriority</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>OOMScoreAdjust=</varname></term>
+
+ <listitem><para>Sets the adjustment level for the
+ Out-Of-Memory killer for executed processes. Takes an integer
+ between -1000 (to disable OOM killing for this process) and
+ 1000 (to make killing of this process under memory pressure
+ very likely). See <ulink
+ url="https://www.kernel.org/doc/Documentation/filesystems/proc.txt">proc.txt</ulink>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>IOSchedulingClass=</varname></term>
+
+ <listitem><para>Sets the IO scheduling class for executed
+ processes. Takes an integer between 0 and 3 or one of the
+ strings <option>none</option>, <option>realtime</option>,
+ <option>best-effort</option> or <option>idle</option>. See
+ <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>IOSchedulingPriority=</varname></term>
+
+ <listitem><para>Sets the IO scheduling priority for executed
+ processes. Takes an integer between 0 (highest priority) and 7
+ (lowest priority). The available priorities depend on the
+ selected IO scheduling class (see above). See
+ <citerefentry><refentrytitle>ioprio_set</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CPUSchedulingPolicy=</varname></term>
+
+ <listitem><para>Sets the CPU scheduling policy for executed
+ processes. Takes one of
+ <option>other</option>,
+ <option>batch</option>,
+ <option>idle</option>,
+ <option>fifo</option> or
+ <option>rr</option>. See
+ <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CPUSchedulingPriority=</varname></term>
+
+ <listitem><para>Sets the CPU scheduling priority for executed
+ processes. The available priority range depends on the
+ selected CPU scheduling policy (see above). For real-time
+ scheduling policies an integer between 1 (lowest priority) and
+ 99 (highest priority) can be used. See
+ <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CPUSchedulingResetOnFork=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, elevated
+ CPU scheduling priorities and policies will be reset when the
+ executed processes fork, and can hence not leak into child
+ processes. See
+ <citerefentry><refentrytitle>sched_setscheduler</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. Defaults to false.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CPUAffinity=</varname></term>
+
+ <listitem><para>Controls the CPU affinity of the executed
+ processes. Takes a space-separated list of CPU indices. This
+ option may be specified more than once in which case the
+ specified CPU affinity masks are merged. If the empty string
+ is assigned, the mask is reset, all assignments prior to this
+ will have no effect. See
+ <citerefentry><refentrytitle>sched_setaffinity</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>UMask=</varname></term>
+
+ <listitem><para>Controls the file mode creation mask. Takes an
+ access mode in octal notation. See
+ <citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. Defaults to 0022.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Environment=</varname></term>
+
+ <listitem><para>Sets environment variables for executed
+ processes. Takes a space-separated list of variable
+ assignments. This option may be specified more than once in
+ which case all listed variables will be set. If the same
+ variable is set twice, the later setting will override the
+ earlier setting. If the empty string is assigned to this
+ option, the list of environment variables is reset, all prior
+ assignments have no effect. Variable expansion is not
+ performed inside the strings, however, specifier expansion is
+ possible. The $ character has no special meaning. If you need
+ to assign a value containing spaces to a variable, use double
+ quotes (") for the assignment.</para>
+
+ <para>Example:
+ <programlisting>Environment="VAR1=word1 word2" VAR2=word3 "VAR3=$word 5 6"</programlisting>
+ gives three variables <literal>VAR1</literal>,
+ <literal>VAR2</literal>, <literal>VAR3</literal>
+ with the values <literal>word1 word2</literal>,
+ <literal>word3</literal>, <literal>$word 5 6</literal>.
+ </para>
+
+ <para>
+ See
+ <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details about environment variables.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>EnvironmentFile=</varname></term>
+ <listitem><para>Similar to <varname>Environment=</varname> but
+ reads the environment variables from a text file. The text
+ file should contain new-line-separated variable assignments.
+ Empty lines and lines starting with ; or # will be ignored,
+ which may be used for commenting. A line ending with a
+ backslash will be concatenated with the following one,
+ allowing multiline variable definitions. The parser strips
+ leading and trailing whitespace from the values of
+ assignments, unless you use double quotes (").</para>
+
+ <para>The argument passed should be an absolute filename or
+ wildcard expression, optionally prefixed with
+ <literal>-</literal>, which indicates that if the file does
+ not exist, it will not be read and no error or warning message
+ is logged. This option may be specified more than once in
+ which case all specified files are read. If the empty string
+ is assigned to this option, the list of file to read is reset,
+ all prior assignments have no effect.</para>
+
+ <para>The files listed with this directive will be read
+ shortly before the process is executed (more specifically,
+ after all processes from a previous unit state terminated.
+ This means you can generate these files in one unit state, and
+ read it with this option in the next). Settings from these
+ files override settings made with
+ <varname>Environment=</varname>. If the same variable is set
+ twice from these files, the files will be read in the order
+ they are specified and the later setting will override the
+ earlier setting.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>StandardInput=</varname></term>
+ <listitem><para>Controls where file descriptor 0 (STDIN) of
+ the executed processes is connected to. Takes one of
+ <option>null</option>,
+ <option>tty</option>,
+ <option>tty-force</option>,
+ <option>tty-fail</option> or
+ <option>socket</option>.</para>
+
+ <para>If <option>null</option> is selected, standard input
+ will be connected to <filename>/dev/null</filename>, i.e. all
+ read attempts by the process will result in immediate
+ EOF.</para>
+
+ <para>If <option>tty</option> is selected, standard input is
+ connected to a TTY (as configured by
+ <varname>TTYPath=</varname>, see below) and the executed
+ process becomes the controlling process of the terminal. If
+ the terminal is already being controlled by another process,
+ the executed process waits until the current controlling
+ process releases the terminal.</para>
+
+ <para><option>tty-force</option> is similar to
+ <option>tty</option>, but the executed process is forcefully
+ and immediately made the controlling process of the terminal,
+ potentially removing previous controlling processes from the
+ terminal.</para>
+
+ <para><option>tty-fail</option> is similar to
+ <option>tty</option> but if the terminal already has a
+ controlling process start-up of the executed process
+ fails.</para>
+
+ <para>The <option>socket</option> option is only valid in
+ socket-activated services, and only when the socket
+ configuration file (see
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details) specifies a single socket only. If this option is
+ set, standard input will be connected to the socket the
+ service was activated from, which is primarily useful for
+ compatibility with daemons designed for use with the
+ traditional
+ <citerefentry><refentrytitle>inetd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ daemon.</para>
+
+ <para>This setting defaults to
+ <option>null</option>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>StandardOutput=</varname></term>
+ <listitem><para>Controls where file descriptor 1 (STDOUT) of
+ the executed processes is connected to. Takes one of
+ <option>inherit</option>,
+ <option>null</option>,
+ <option>tty</option>,
+ <option>journal</option>,
+ <option>syslog</option>,
+ <option>kmsg</option>,
+ <option>journal+console</option>,
+ <option>syslog+console</option>,
+ <option>kmsg+console</option> or
+ <option>socket</option>.</para>
+
+ <para><option>inherit</option> duplicates the file descriptor
+ of standard input for standard output.</para>
+
+ <para><option>null</option> connects standard output to
+ <filename>/dev/null</filename>, i.e. everything written to it
+ will be lost.</para>
+
+ <para><option>tty</option> connects standard output to a tty
+ (as configured via <varname>TTYPath=</varname>, see below). If
+ the TTY is used for output only, the executed process will not
+ become the controlling process of the terminal, and will not
+ fail or wait for other processes to release the
+ terminal.</para>
+
+ <para><option>journal</option> connects standard output with
+ the journal which is accessible via
+ <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
+ Note that everything that is written to syslog or kmsg (see
+ below) is implicitly stored in the journal as well, the
+ specific two options listed below are hence supersets of this
+ one.</para>
+
+ <para><option>syslog</option> connects standard output to the
+ <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ system syslog service, in addition to the journal. Note that
+ the journal daemon is usually configured to forward everything
+ it receives to syslog anyway, in which case this option is no
+ different from <option>journal</option>.</para>
+
+ <para><option>kmsg</option> connects standard output with the
+ kernel log buffer which is accessible via
+ <citerefentry project='man-pages'><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ in addition to the journal. The journal daemon might be
+ configured to send all logs to kmsg anyway, in which case this
+ option is no different from <option>journal</option>.</para>
+
+ <para><option>journal+console</option>,
+ <option>syslog+console</option> and
+ <option>kmsg+console</option> work in a similar way as the
+ three options above but copy the output to the system console
+ as well.</para>
+
+ <para><option>socket</option> connects standard output to a
+ socket acquired via socket activation. The semantics are
+ similar to the same option of
+ <varname>StandardInput=</varname>.</para>
+
+ <para>This setting defaults to the value set with
+ <option>DefaultStandardOutput=</option> in
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which defaults to <option>journal</option>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>StandardError=</varname></term>
+ <listitem><para>Controls where file descriptor 2 (STDERR) of
+ the executed processes is connected to. The available options
+ are identical to those of <varname>StandardOutput=</varname>,
+ with one exception: if set to <option>inherit</option> the
+ file descriptor used for standard output is duplicated for
+ standard error. This setting defaults to the value set with
+ <option>DefaultStandardError=</option> in
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which defaults to <option>inherit</option>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TTYPath=</varname></term>
+ <listitem><para>Sets the terminal device node to use if
+ standard input, output, or error are connected to a TTY (see
+ above). Defaults to
+ <filename>/dev/console</filename>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TTYReset=</varname></term>
+ <listitem><para>Reset the terminal device specified with
+ <varname>TTYPath=</varname> before and after execution.
+ Defaults to <literal>no</literal>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TTYVHangup=</varname></term>
+ <listitem><para>Disconnect all clients which have opened the
+ terminal device specified with <varname>TTYPath=</varname>
+ before and after execution. Defaults to
+ <literal>no</literal>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>TTYVTDisallocate=</varname></term>
+ <listitem><para>If the terminal device specified with
+ <varname>TTYPath=</varname> is a virtual console terminal, try
+ to deallocate the TTY before and after execution. This ensures
+ that the screen and scrollback buffer is cleared. Defaults to
+ <literal>no</literal>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>SyslogIdentifier=</varname></term>
+ <listitem><para>Sets the process name to prefix log lines sent
+ to the logging system or the kernel log buffer with. If not
+ set, defaults to the process name of the executed process.
+ This option is only useful when
+ <varname>StandardOutput=</varname> or
+ <varname>StandardError=</varname> are set to
+ <option>syslog</option>, <option>journal</option> or
+ <option>kmsg</option> (or to the same settings in combination
+ with <option>+console</option>).</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>SyslogFacility=</varname></term>
+ <listitem><para>Sets the syslog facility to use when logging
+ to syslog. One of <option>kern</option>,
+ <option>user</option>, <option>mail</option>,
+ <option>daemon</option>, <option>auth</option>,
+ <option>syslog</option>, <option>lpr</option>,
+ <option>news</option>, <option>uucp</option>,
+ <option>cron</option>, <option>authpriv</option>,
+ <option>ftp</option>, <option>local0</option>,
+ <option>local1</option>, <option>local2</option>,
+ <option>local3</option>, <option>local4</option>,
+ <option>local5</option>, <option>local6</option> or
+ <option>local7</option>. See
+ <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for details. This option is only useful when
+ <varname>StandardOutput=</varname> or
+ <varname>StandardError=</varname> are set to
+ <option>syslog</option>. Defaults to
+ <option>daemon</option>.</para></listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><varname>SyslogLevel=</varname></term>
+ <listitem><para>Default syslog level to use when logging to
+ syslog or the kernel log buffer. One of
+ <option>emerg</option>,
+ <option>alert</option>,
+ <option>crit</option>,
+ <option>err</option>,
+ <option>warning</option>,
+ <option>notice</option>,
+ <option>info</option>,
+ <option>debug</option>. See
+ <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for details. This option is only useful when
+ <varname>StandardOutput=</varname> or
+ <varname>StandardError=</varname> are set to
+ <option>syslog</option> or <option>kmsg</option>. Note that
+ individual lines output by the daemon might be prefixed with a
+ different log level which can be used to override the default
+ log level specified here. The interpretation of these prefixes
+ may be disabled with <varname>SyslogLevelPrefix=</varname>,
+ see below. For details see
+ <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+
+ Defaults to
+ <option>info</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SyslogLevelPrefix=</varname></term>
+ <listitem><para>Takes a boolean argument. If true and
+ <varname>StandardOutput=</varname> or
+ <varname>StandardError=</varname> are set to
+ <option>syslog</option>, <option>kmsg</option> or
+ <option>journal</option>, log lines written by the executed
+ process that are prefixed with a log level will be passed on
+ to syslog with this log level set but the prefix removed. If
+ set to false, the interpretation of these prefixes is disabled
+ and the logged lines are passed on as-is. For details about
+ this prefixing see
+ <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ Defaults to true.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>TimerSlackNSec=</varname></term>
+ <listitem><para>Sets the timer slack in nanoseconds for the
+ executed processes. The timer slack controls the accuracy of
+ wake-ups triggered by timers. See
+ <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for more information. Note that in contrast to most other time
+ span definitions this parameter takes an integer value in
+ nano-seconds if no unit is specified. The usual time units are
+ understood too.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>LimitCPU=</varname></term>
+ <term><varname>LimitFSIZE=</varname></term>
+ <term><varname>LimitDATA=</varname></term>
+ <term><varname>LimitSTACK=</varname></term>
+ <term><varname>LimitCORE=</varname></term>
+ <term><varname>LimitRSS=</varname></term>
+ <term><varname>LimitNOFILE=</varname></term>
+ <term><varname>LimitAS=</varname></term>
+ <term><varname>LimitNPROC=</varname></term>
+ <term><varname>LimitMEMLOCK=</varname></term>
+ <term><varname>LimitLOCKS=</varname></term>
+ <term><varname>LimitSIGPENDING=</varname></term>
+ <term><varname>LimitMSGQUEUE=</varname></term>
+ <term><varname>LimitNICE=</varname></term>
+ <term><varname>LimitRTPRIO=</varname></term>
+ <term><varname>LimitRTTIME=</varname></term>
+ <listitem><para>These settings set both soft and hard limits
+ of various resources for executed processes. See
+ <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. Use the string <varname>infinity</varname> to
+ configure no limit on a specific resource.</para></listitem>
+
+ <table>
+ <title>Limit directives and their equivalent with ulimit</title>
+
+ <tgroup cols='2'>
+ <colspec colname='directive' />
+ <colspec colname='equivalent' />
+ <thead>
+ <row>
+ <entry>Directive</entry>
+ <entry>ulimit equivalent</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>LimitCPU</entry>
+ <entry>ulimit -t</entry>
+ </row>
+ <row>
+ <entry>LimitFSIZE</entry>
+ <entry>ulimit -f</entry>
+ </row>
+ <row>
+ <entry>LimitDATA</entry>
+ <entry>ulimit -d</entry>
+ </row>
+ <row>
+ <entry>LimitSTACK</entry>
+ <entry>ulimit -s</entry>
+ </row>
+ <row>
+ <entry>LimitCORE</entry>
+ <entry>ulimit -c</entry>
+ </row>
+ <row>
+ <entry>LimitRSS</entry>
+ <entry>ulimit -m</entry>
+ </row>
+ <row>
+ <entry>LimitNOFILE</entry>
+ <entry>ulimit -n</entry>
+ </row>
+ <row>
+ <entry>LimitAS</entry>
+ <entry>ulimit -v</entry>
+ </row>
+ <row>
+ <entry>LimitNPROC</entry>
+ <entry>ulimit -u</entry>
+ </row>
+ <row>
+ <entry>LimitMEMLOCK</entry>
+ <entry>ulimit -l</entry>
+ </row>
+ <row>
+ <entry>LimitLOCKS</entry>
+ <entry>ulimit -x</entry>
+ </row>
+ <row>
+ <entry>LimitSIGPENDING</entry>
+ <entry>ulimit -i</entry>
+ </row>
+ <row>
+ <entry>LimitMSGQUEUE</entry>
+ <entry>ulimit -q</entry>
+ </row>
+ <row>
+ <entry>LimitNICE</entry>
+ <entry>ulimit -e</entry>
+ </row>
+ <row>
+ <entry>LimitRTPRIO</entry>
+ <entry>ulimit -r</entry>
+ </row>
+ <row>
+ <entry>LimitRTTIME</entry>
+ <entry>No equivalent</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PAMName=</varname></term>
+ <listitem><para>Sets the PAM service name to set up a session
+ as. If set, the executed process will be registered as a PAM
+ session under the specified service name. This is only useful
+ in conjunction with the <varname>User=</varname> setting. If
+ not set, no PAM session will be opened for the executed
+ processes. See
+ <citerefentry project='man-pages'><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CapabilityBoundingSet=</varname></term>
+
+ <listitem><para>Controls which capabilities to include in the
+ capability bounding set for the executed process. See
+ <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details. Takes a whitespace-separated list of capability
+ names as read by
+ <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ e.g. <constant>CAP_SYS_ADMIN</constant>,
+ <constant>CAP_DAC_OVERRIDE</constant>,
+ <constant>CAP_SYS_PTRACE</constant>. Capabilities listed will
+ be included in the bounding set, all others are removed. If
+ the list of capabilities is prefixed with
+ <literal>~</literal>, all but the listed capabilities will be
+ included, the effect of the assignment inverted. Note that
+ this option also affects the respective capabilities in the
+ effective, permitted and inheritable capability sets, on top
+ of what <varname>Capabilities=</varname> does. If this option
+ is not used, the capability bounding set is not modified on
+ process execution, hence no limits on the capabilities of the
+ process are enforced. This option may appear more than once in
+ which case the bounding sets are merged. If the empty string
+ is assigned to this option, the bounding set is reset to the
+ empty capability set, and all prior settings have no effect.
+ If set to <literal>~</literal> (without any further argument),
+ the bounding set is reset to the full set of available
+ capabilities, also undoing any previous
+ settings.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SecureBits=</varname></term>
+ <listitem><para>Controls the secure bits set for the executed
+ process. Takes a space-separated combination of options from
+ the following list:
+ <option>keep-caps</option>,
+ <option>keep-caps-locked</option>,
+ <option>no-setuid-fixup</option>,
+ <option>no-setuid-fixup-locked</option>,
+ <option>noroot</option>, and
+ <option>noroot-locked</option>.
+ This option may appear more than once in which case the secure
+ bits are ORed. If the empty string is assigned to this option,
+ the bits are reset to 0. See
+ <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Capabilities=</varname></term>
+ <listitem><para>Controls the
+ <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ set for the executed process. Take a capability string
+ describing the effective, permitted and inherited capability
+ sets as documented in
+ <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ Note that these capability sets are usually influenced (and
+ filtered) by the capabilities attached to the executed file.
+ Due to that <varname>CapabilityBoundingSet=</varname> is
+ probably a much more useful setting.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ReadWriteDirectories=</varname></term>
+ <term><varname>ReadOnlyDirectories=</varname></term>
+ <term><varname>InaccessibleDirectories=</varname></term>
+
+ <listitem><para>Sets up a new file system namespace for
+ executed processes. These options may be used to limit access
+ a process might have to the main file system hierarchy. Each
+ setting takes a space-separated list of absolute directory
+ paths. Directories listed in
+ <varname>ReadWriteDirectories=</varname> are accessible from
+ within the namespace with the same access rights as from
+ outside. Directories listed in
+ <varname>ReadOnlyDirectories=</varname> are accessible for
+ reading only, writing will be refused even if the usual file
+ access controls would permit this. Directories listed in
+ <varname>InaccessibleDirectories=</varname> will be made
+ inaccessible for processes inside the namespace. Note that
+ restricting access with these options does not extend to
+ submounts of a directory that are created later on. These
+ options may be specified more than once in which case all
+ directories listed will have limited access from within the
+ namespace. If the empty string is assigned to this option, the
+ specific list is reset, and all prior assignments have no
+ effect.</para>
+ <para>Paths in
+ <varname>ReadOnlyDirectories=</varname>
+ and
+ <varname>InaccessibleDirectories=</varname>
+ may be prefixed with
+ <literal>-</literal>, in which case
+ they will be ignored when they do not
+ exist. Note that using this
+ setting will disconnect propagation of
+ mounts from the service to the host
+ (propagation in the opposite direction
+ continues to work). This means that
+ this setting may not be used for
+ services which shall be able to
+ install mount points in the main mount
+ namespace.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PrivateTmp=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, sets up a
+ new file system namespace for the executed processes and
+ mounts private <filename>/tmp</filename> and
+ <filename>/var/tmp</filename> directories inside it that is
+ not shared by processes outside of the namespace. This is
+ useful to secure access to temporary files of the process, but
+ makes sharing between processes via <filename>/tmp</filename>
+ or <filename>/var/tmp</filename> impossible. If this is
+ enabled, all temporary files created by a service in these
+ directories will be removed after the service is stopped.
+ Defaults to false. It is possible to run two or more units
+ within the same private <filename>/tmp</filename> and
+ <filename>/var/tmp</filename> namespace by using the
+ <varname>JoinsNamespaceOf=</varname> directive, see
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details. Note that using this setting will disconnect
+ propagation of mounts from the service to the host
+ (propagation in the opposite direction continues to work).
+ This means that this setting may not be used for services
+ which shall be able to install mount points in the main mount
+ namespace.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PrivateDevices=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, sets up a
+ new /dev namespace for the executed processes and only adds
+ API pseudo devices such as <filename>/dev/null</filename>,
+ <filename>/dev/zero</filename> or
+ <filename>/dev/random</filename> (as well as the pseudo TTY
+ subsystem) to it, but no physical devices such as
+ <filename>/dev/sda</filename>. This is useful to securely turn
+ off physical device access by the executed process. Defaults
+ to false. Enabling this option will also remove
+ <constant>CAP_MKNOD</constant> from the capability bounding
+ set for the unit (see above), and set
+ <varname>DevicePolicy=closed</varname> (see
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details). Note that using this setting will disconnect
+ propagation of mounts from the service to the host
+ (propagation in the opposite direction continues to work).
+ This means that this setting may not be used for services
+ which shall be able to install mount points in the main mount
+ namespace.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PrivateNetwork=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, sets up a
+ new network namespace for the executed processes and
+ configures only the loopback network device
+ <literal>lo</literal> inside it. No other network devices will
+ be available to the executed process. This is useful to
+ securely turn off network access by the executed process.
+ Defaults to false. It is possible to run two or more units
+ within the same private network namespace by using the
+ <varname>JoinsNamespaceOf=</varname> directive, see
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details. Note that this option will disconnect all socket
+ families from the host, this includes AF_NETLINK and AF_UNIX.
+ The latter has the effect that AF_UNIX sockets in the abstract
+ socket namespace will become unavailable to the processes
+ (however, those located in the file system will continue to be
+ accessible).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ProtectSystem=</varname></term>
+
+ <listitem><para>Takes a boolean argument or
+ <literal>full</literal>. If true, mounts the
+ <filename>/usr</filename> and <filename>/boot</filename>
+ directories read-only for processes invoked by this unit. If
+ set to <literal>full</literal>, the <filename>/etc</filename>
+ directory is mounted read-only, too. This setting ensures that
+ any modification of the vendor supplied operating system (and
+ optionally its configuration) is prohibited for the service.
+ It is recommended to enable this setting for all long-running
+ services, unless they are involved with system updates or need
+ to modify the operating system in other ways. Note however
+ that processes retaining the CAP_SYS_ADMIN capability can undo
+ the effect of this setting. This setting is hence particularly
+ useful for daemons which have this capability removed, for
+ example with <varname>CapabilityBoundingSet=</varname>.
+ Defaults to off.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ProtectHome=</varname></term>
+
+ <listitem><para>Takes a boolean argument or
+ <literal>read-only</literal>. If true, the directories
+ <filename>/home</filename> and <filename>/run/user</filename>
+ are made inaccessible and empty for processes invoked by this
+ unit. If set to <literal>read-only</literal>, the two
+ directories are made read-only instead. It is recommended to
+ enable this setting for all long-running services (in
+ particular network-facing ones), to ensure they cannot get
+ access to private user data, unless the services actually
+ require access to the user's private data. Note however that
+ processes retaining the CAP_SYS_ADMIN capability can undo the
+ effect of this setting. This setting is hence particularly
+ useful for daemons which have this capability removed, for
+ example with <varname>CapabilityBoundingSet=</varname>.
+ Defaults to off.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>MountFlags=</varname></term>
+
+ <listitem><para>Takes a mount propagation flag:
+ <option>shared</option>, <option>slave</option> or
+ <option>private</option>, which control whether mounts in the
+ file system namespace set up for this unit's processes will
+ receive or propagate mounts or unmounts. See
+ <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details. Defaults to <option>shared</option>. Use
+ <option>shared</option> to ensure that mounts and unmounts are
+ propagated from the host to the container and vice versa. Use
+ <option>slave</option> to run processes so that none of their
+ mounts and unmounts will propagate to the host. Use
+ <option>private</option> to also ensure that no mounts and
+ unmounts from the host will propagate into the unit processes'
+ namespace. Note that <option>slave</option> means that file
+ systems mounted on the host might stay mounted continuously in
+ the unit's namespace, and thus keep the device busy. Note that
+ the file system namespace related options
+ (<varname>PrivateTmp=</varname>,
+ <varname>PrivateDevices=</varname>,
+ <varname>ProtectSystem=</varname>,
+ <varname>ProtectHome=</varname>,
+ <varname>ReadOnlyDirectories=</varname>,
+ <varname>InaccessibleDirectories=</varname> and
+ <varname>ReadWriteDirectories=</varname>) require that mount
+ and unmount propagation from the unit's file system namespace
+ is disabled, and hence downgrade <option>shared</option> to
+ <option>slave</option>. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>UtmpIdentifier=</varname></term>
+
+ <listitem><para>Takes a four character identifier string for
+ an utmp/wtmp entry for this service. This should only be set
+ for services such as <command>getty</command> implementations
+ where utmp/wtmp entries must be created and cleared before and
+ after execution. If the configured string is longer than four
+ characters, it is truncated and the terminal four characters
+ are used. This setting interprets %I style string
+ replacements. This setting is unset by default, i.e. no
+ utmp/wtmp entries are created or cleaned up for this
+ service.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SELinuxContext=</varname></term>
+
+ <listitem><para>Set the SELinux security context of the
+ executed process. If set, this will override the automated
+ domain transition. However, the policy still needs to
+ authorize the transition. This directive is ignored if SELinux
+ is disabled. If prefixed by <literal>-</literal>, all errors
+ will be ignored. See
+ <citerefentry><refentrytitle>setexeccon</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>AppArmorProfile=</varname></term>
+
+ <listitem><para>Takes a profile name as argument. The process
+ executed by the unit will switch to this profile when started.
+ Profiles must already be loaded in the kernel, or the unit
+ will fail. This result in a non operation if AppArmor is not
+ enabled. If prefixed by <literal>-</literal>, all errors will
+ be ignored. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SmackProcessLabel=</varname></term>
+
+ <listitem><para>Takes a <option>SMACK64</option> security
+ label as argument. The process executed by the unit will be
+ started under this label and SMACK will decide whether the
+ processes is allowed to run or not based on it. The process
+ will continue to run under the label specified here unless the
+ executable has its own <option>SMACK64EXEC</option> label, in
+ which case the process will transition to run under that
+ label. When not specified, the label that systemd is running
+ under is used. This directive is ignored if SMACK is
+ disabled.</para>
+
+ <para>The value may be prefixed by <literal>-</literal>, in
+ which case all errors will be ignored. An empty value may be
+ specified to unset previous assignments.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>IgnoreSIGPIPE=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, causes
+ <constant>SIGPIPE</constant> to be ignored in the executed
+ process. Defaults to true because <constant>SIGPIPE</constant>
+ generally is useful only in shell pipelines.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>NoNewPrivileges=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If true, ensures
+ that the service process and all its children can never gain
+ new privileges. This option is more powerful than the
+ respective secure bits flags (see above), as it also prohibits
+ UID changes of any kind. This is the simplest, most effective
+ way to ensure that a process and its children can never
+ elevate privileges again.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SystemCallFilter=</varname></term>
+
+ <listitem><para>Takes a space-separated list of system call
+ names. If this setting is used, all system calls executed by
+ the unit processes except for the listed ones will result in
+ immediate process termination with the
+ <constant>SIGSYS</constant> signal (whitelisting). If the
+ first character of the list is <literal>~</literal>, the
+ effect is inverted: only the listed system calls will result
+ in immediate process termination (blacklisting). If running in
+ user mode and this option is used,
+ <varname>NoNewPrivileges=yes</varname> is implied. This
+ feature makes use of the Secure Computing Mode 2 interfaces of
+ the kernel ('seccomp filtering') and is useful for enforcing a
+ minimal sandboxing environment. Note that the
+ <function>execve</function>,
+ <function>rt_sigreturn</function>,
+ <function>sigreturn</function>,
+ <function>exit_group</function>, <function>exit</function>
+ system calls are implicitly whitelisted and do not need to be
+ listed explicitly. This option may be specified more than once
+ in which case the filter masks are merged. If the empty string
+ is assigned, the filter is reset, all prior assignments will
+ have no effect.</para>
+
+ <para>If you specify both types of this option (i.e.
+ whitelisting and blacklisting), the first encountered will
+ take precedence and will dictate the default action
+ (termination or approval of a system call). Then the next
+ occurrences of this option will add or delete the listed
+ system calls from the set of the filtered system calls,
+ depending of its type and the default action. (For example, if
+ you have started with a whitelisting of
+ <function>read</function> and <function>write</function>, and
+ right after it add a blacklisting of
+ <function>write</function>, then <function>write</function>
+ will be removed from the set.) </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SystemCallErrorNumber=</varname></term>
+
+ <listitem><para>Takes an <literal>errno</literal> error number
+ name to return when the system call filter configured with
+ <varname>SystemCallFilter=</varname> is triggered, instead of
+ terminating the process immediately. Takes an error name such
+ as <constant>EPERM</constant>, <constant>EACCES</constant> or
+ <constant>EUCLEAN</constant>. When this setting is not used,
+ or when the empty string is assigned, the process will be
+ terminated immediately when the filter is
+ triggered.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SystemCallArchitectures=</varname></term>
+
+ <listitem><para>Takes a space separated list of architecture
+ identifiers to include in the system call filter. The known
+ architecture identifiers are <constant>x86</constant>,
+ <constant>x86-64</constant>, <constant>x32</constant>,
+ <constant>arm</constant> as well as the special identifier
+ <constant>native</constant>. Only system calls of the
+ specified architectures will be permitted to processes of this
+ unit. This is an effective way to disable compatibility with
+ non-native architectures for processes, for example to
+ prohibit execution of 32-bit x86 binaries on 64-bit x86-64
+ systems. The special <constant>native</constant> identifier
+ implicitly maps to the native architecture of the system (or
+ more strictly: to the architecture the system manager is
+ compiled for). If running in user mode and this option is
+ used, <varname>NoNewPrivileges=yes</varname> is implied. Note
+ that setting this option to a non-empty list implies that
+ <constant>native</constant> is included too. By default, this
+ option is set to the empty list, i.e. no architecture system
+ call filtering is applied.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RestrictAddressFamilies=</varname></term>
+
+ <listitem><para>Restricts the set of socket address families
+ accessible to the processes of this unit. Takes a
+ space-separated list of address family names to whitelist,
+ such as
+ <constant>AF_UNIX</constant>,
+ <constant>AF_INET</constant> or
+ <constant>AF_INET6</constant>. When
+ prefixed with <constant>~</constant> the listed address
+ families will be applied as blacklist, otherwise as whitelist.
+ Note that this restricts access to the
+ <citerefentry><refentrytitle>socket</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ system call only. Sockets passed into the process by other
+ means (for example, by using socket activation with socket
+ units, see
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
+ are unaffected. Also, sockets created with
+ <function>socketpair()</function> (which creates connected
+ AF_UNIX sockets only) are unaffected. Note that this option
+ has no effect on 32-bit x86 and is ignored (but works
+ correctly on x86-64). If running in user mode and this option
+ is used, <varname>NoNewPrivileges=yes</varname> is implied. By
+ default, no restriction applies, all address families are
+ accessible to processes. If assigned the empty string, any
+ previous list changes are undone.</para>
+
+ <para>Use this option to limit exposure of processes to remote
+ systems, in particular via exotic network protocols. Note that
+ in most cases, the local <constant>AF_UNIX</constant> address
+ family should be included in the configured whitelist as it is
+ frequently used for local communication, including for
+ <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ logging.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Personality=</varname></term>
+
+ <listitem><para>Controls which kernel architecture
+ <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ shall report, when invoked by unit processes. Takes one of
+ <constant>x86</constant> and <constant>x86-64</constant>. This
+ is useful when running 32-bit services on a 64-bit host
+ system. If not specified, the personality is left unmodified
+ and thus reflects the personality of the host system's
+ kernel.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RuntimeDirectory=</varname></term>
+ <term><varname>RuntimeDirectoryMode=</varname></term>
+
+ <listitem><para>Takes a list of directory names. If set, one
+ or more directories by the specified names will be created
+ below <filename>/run</filename> (for system services) or below
+ <varname>$XDG_RUNTIME_DIR</varname> (for user services) when
+ the unit is started, and removed when the unit is stopped. The
+ directories will have the access mode specified in
+ <varname>RuntimeDirectoryMode=</varname>, and will be owned by
+ the user and group specified in <varname>User=</varname> and
+ <varname>Group=</varname>. Use this to manage one or more
+ runtime directories of the unit and bind their lifetime to the
+ daemon runtime. The specified directory names must be
+ relative, and may not include a <literal>/</literal>, i.e.
+ must refer to simple directories to create or remove. This is
+ particularly useful for unprivileged daemons that cannot
+ create runtime directories in <filename>/run</filename> due to
+ lack of privileges, and to make sure the runtime directory is
+ cleaned up automatically after use. For runtime directories
+ that require more complex or different configuration or
+ lifetime guarantees, please consider using
+ <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
+ </varlistentry>
+
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Environment variables in spawned processes</title>
+
+ <para>Processes started by the system are executed in a clean
+ environment in which select variables listed below are set. System
+ processes started by systemd do not inherit variables from PID 1,
+ but processes started by user systemd instances inherit all
+ environment variables from the user systemd instance.
+ </para>
+
+ <variablelist class='environment-variables'>
+ <varlistentry>
+ <term><varname>$PATH</varname></term>
+
+ <listitem><para>Colon-separated list of directories to use
+ when launching executables. Systemd uses a fixed value of
+ <filename>/usr/local/sbin</filename>:<filename>/usr/local/bin</filename>:<filename>/usr/sbin</filename>:<filename>/usr/bin</filename>:<filename>/sbin</filename>:<filename>/bin</filename>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$LANG</varname></term>
+
+ <listitem><para>Locale. Can be set in
+ <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ or on the kernel command line (see
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ and
+ <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>).
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$USER</varname></term>
+ <term><varname>$LOGNAME</varname></term>
+ <term><varname>$HOME</varname></term>
+ <term><varname>$SHELL</varname></term>
+
+ <listitem><para>User name (twice), home directory, and the
+ login shell. The variables are set for the units that have
+ <varname>User=</varname> set, which includes user
+ <command>systemd</command> instances. See
+ <citerefentry><refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$XDG_RUNTIME_DIR</varname></term>
+
+ <listitem><para>The directory for volatile state. Set for the
+ user <command>systemd</command> instance, and also in user
+ sessions. See
+ <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$XDG_SESSION_ID</varname></term>
+ <term><varname>$XDG_SEAT</varname></term>
+ <term><varname>$XDG_VTNR</varname></term>
+
+ <listitem><para>The identifier of the session, the seat name,
+ and virtual terminal of the session. Set by
+ <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ for login sessions. <varname>$XDG_SEAT</varname> and
+ <varname>$XDG_VTNR</varname> will only be set when attached to
+ a seat and a tty.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$MAINPID</varname></term>
+
+ <listitem><para>The PID of the units main process if it is
+ known. This is only set for control processes as invoked by
+ <varname>ExecReload=</varname> and similar. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$MANAGERPID</varname></term>
+
+ <listitem><para>The PID of the user <command>systemd</command>
+ instance, set for processes spawned by it. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$LISTEN_FDS</varname></term>
+ <term><varname>$LISTEN_PID</varname></term>
+
+ <listitem><para>Information about file descriptors passed to a
+ service for socket activation. See
+ <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$TERM</varname></term>
+
+ <listitem><para>Terminal type, set only for units connected to
+ a terminal (<varname>StandardInput=tty</varname>,
+ <varname>StandardOutput=tty</varname>, or
+ <varname>StandardError=tty</varname>). See
+ <citerefentry project='man-pages'><refentrytitle>termcap</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para></listitem>
+ </varlistentry>
+ </variablelist>
+
+ <para>Additional variables may be configured by the following
+ means: for processes spawned in specific units, use the
+ <varname>Environment=</varname> and
+ <varname>EnvironmentFile=</varname> options above; to specify
+ variables globally, use <varname>DefaultEnvironment=</varname>
+ (see
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
+ or the kernel option <varname>systemd.setenv=</varname> (see
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>).
+ Additional variables may also be set through PAM,
+ cf. <citerefentry project='man-pages'><refentrytitle>pam_env</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>exec</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
</refentry>
~ianmdlvl / elogind.git / blobdiff