mirror of
https://github.com/systemd/systemd.git
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82adf6af7c
Let's always call the security labels the same way: SMACK: "Smack Label" SELINUX: "SELinux Security Context" And the low-level encapsulation is called "seclabel". Now let's hope we stick to this vocabulary in future, too, and don't mix "label"s and "security contexts" and so on wildly.
1186 lines
70 KiB
XML
1186 lines
70 KiB
XML
<?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
|
||
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
||
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
||
|
||
<!--
|
||
This file is part of systemd.
|
||
|
||
Copyright 2010 Lennart Poettering
|
||
|
||
systemd is free software; you can redistribute it and/or modify it
|
||
under the terms of the GNU Lesser General Public License as published by
|
||
the Free Software Foundation; either version 2.1 of the License, or
|
||
(at your option) any later version.
|
||
|
||
systemd is distributed in the hope that it will be useful, but
|
||
WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public License
|
||
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
||
-->
|
||
|
||
<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><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 indexes. This option may
|
||
be specified more than once in which
|
||
case the specificed CPU affinity masks
|
||
are merged. If the empty string is
|
||
assigned, the mask is reset, all
|
||
assignments prior to this will have no
|
||
effect. See
|
||
<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><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. 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>. 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. 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.
|
||
<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. <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. 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. 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>syslog</option>,
|
||
<option>kmsg</option>,
|
||
<option>journal</option>,
|
||
<option>syslog+console</option>,
|
||
<option>kmsg+console</option>,
|
||
<option>journal+console</option> or
|
||
<option>socket</option>. If set to
|
||
<option>inherit</option>, the file
|
||
descriptor of standard input is
|
||
duplicated for standard output. If set
|
||
to <option>null</option>, standard
|
||
output will be connected to
|
||
<filename>/dev/null</filename>,
|
||
i.e. everything written to it will be
|
||
lost. If set to <option>tty</option>,
|
||
standard output will be connected 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. <option>syslog</option>
|
||
connects standard output to the
|
||
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
||
system syslog
|
||
service. <option>kmsg</option>
|
||
connects it with the kernel log buffer
|
||
which is accessible via
|
||
<citerefentry><refentrytitle>dmesg</refentrytitle><manvolnum>1</manvolnum></citerefentry>. <option>journal</option>
|
||
connects it 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 is implicitly stored
|
||
in the journal as well, those options
|
||
are hence supersets of this
|
||
one). <option>syslog+console</option>,
|
||
<option>journal+console</option> and
|
||
<option>kmsg+console</option> work
|
||
similarly but copy the output to the
|
||
system console as
|
||
well. <option>socket</option> connects
|
||
standard output to a socket from
|
||
socket activation, semantics are
|
||
similar to the respective option of
|
||
<varname>StandardInput=</varname>.
|
||
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 stderr 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 syslog or
|
||
the kernel log buffer with. If not set,
|
||
defaults to the process name of the
|
||
executed process. This option is only
|
||
useful when
|
||
<varname>StandardOutput=</varname> or
|
||
<varname>StandardError=</varname> are
|
||
set to <option>syslog</option> or
|
||
<option>kmsg</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><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><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 control
|
||
various resource limits 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>
|
||
</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><refentrytitle>pam</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
for details.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>TCPWrapName=</varname></term>
|
||
<listitem><para>If this is a
|
||
socket-activated service, this sets the
|
||
tcpwrap service name to check the
|
||
permission for the current connection
|
||
with. This is only useful in
|
||
conjunction with socket-activated
|
||
services, and stream sockets (TCP) in
|
||
particular. It has no effect on other
|
||
socket types (e.g. datagram/UDP) and
|
||
on processes unrelated to socket-based
|
||
activation. If the tcpwrap
|
||
verification fails, daemon start-up
|
||
will fail and the connection is
|
||
terminated. See
|
||
<citerefentry><refentrytitle>tcpd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
for details. Note that this option may
|
||
be used to do access control checks
|
||
only. Shell commands and commands
|
||
described in
|
||
<citerefentry><refentrytitle>hosts_options</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
are not supported.</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><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. See
|
||
<citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||
for details. Takes a list of strings:
|
||
<option>keep-caps</option>,
|
||
<option>keep-caps-locked</option>,
|
||
<option>no-setuid-fixup</option>,
|
||
<option>no-setuid-fixup-locked</option>,
|
||
<option>noroot</option> and/or
|
||
<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.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Capabilities=</varname></term>
|
||
<listitem><para>Controls the
|
||
<citerefentry><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 by the capabilities
|
||
attached to the executed file. Due to
|
||
that
|
||
<varname>CapabilityBoundingSet=</varname>
|
||
is probably the 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. You must list
|
||
submounts separately in these settings
|
||
to ensure the same limited
|
||
access. 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.</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. All temporary data created
|
||
by service will be removed after
|
||
the service is stopped. Defaults to
|
||
false. Note that 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.</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. Note that
|
||
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.</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> 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.</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 the file system
|
||
namespace set up for this unit's
|
||
processes will receive or propagate
|
||
new mounts. See
|
||
<citerefentry><refentrytitle>mount</refentrytitle><manvolnum>2</manvolnum></citerefentry>
|
||
for details. Default to
|
||
<option>shared</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 autorize 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>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
|
||
process 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 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></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>$PATH</varname></term>
|
||
|
||
<listitem><para>Colon-separated list
|
||
of directiories to use when launching
|
||
executables. Systemd uses a fixed
|
||
value of
|
||
<filename>/usr/local/sbin</filename>:<filename>/usr/local/bin</filename>:<filename>/usr/sbin</filename>:<filename>/usr/bin</filename>:<filename>/sbin</filename>:<filename>/bin</filename>.
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>$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>$MANAGERPID</varname></term>
|
||
|
||
<listitem><para>The PID of the user
|
||
<command>systemd</command> instance,
|
||
set for processes spawned by it.
|
||
</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>$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><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,
|
||
c.f. <citerefentry><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>8</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>exec</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|