<refsect1>
<title>Description</title>
- <para>Unit configuration files for services, sockets
+ <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 three unit types. See
+ 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
octal notation. See
<citerefentry><refentrytitle>umask</refentrytitle><manvolnum>2</manvolnum></citerefentry>
for details. Defaults to
- 0002.</para></listitem>
+ 0022.</para></listitem>
</varlistentry>
<varlistentry>
assignments. Empty lines and lines
starting with ; or # will be ignored,
which may be used for commenting. The
+ parser strips leading and
+ trailing whitespace from the values
+ of assignments, unless you use
+ double quotes (").
+ The
argument passed should be an absolute
file name, optionally prefixed with
"-", which indicates that if the file
does not exist it won't be read and no
error or warning message is
- logged.</para></listitem>
+ logged. 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>
terminal. <option>syslog</option>
connects standard output to the
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- system logger. <option>kmsg</option>
+ 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>syslog+console</option>
socket activation, semantics are
similar to the respective option of
<varname>StandardInput=</varname>.
- This setting defaults to
- <option>inherit</option>.</para></listitem>
+ This setting defaults to the value set
+ with
+ <option>DefaultStandardOutput=</option>
+ in
+ <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which defaults to
+ <option>syslog</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>StandardError=</varname></term>
<option>inherit</option> the file
descriptor used for standard output is
duplicated for standard error. This
- setting defaults to
+ setting defaults to the value set with
+ <option>DefaultStandardError=</option>
+ in
+ <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ which defaults to
<option>inherit</option>.</para></listitem>
</varlistentry>
<varlistentry>
<filename>/dev/console</filename>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>SyslogIdentifer=</varname></term>
+ <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 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
various resource limits for executed
processes. See
<citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
- for details.</para></listitem>
+ for details. Use the string
+ <varname>infinity</varname> to
+ configure no limit on a specific
+ resource.</para></listitem>
</varlistentry>
<varlistentry>
</varlistentry>
<varlistentry>
- <term><varname>Capabilities=</varname></term>
- <listitem><para>Controls the
+ <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>
- set for the executed process. Take a
- capability string as described in
- <citerefentry><refentrytitle>cap_from_text</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- Note that this capability set is
- usually influenced by the capabilities
- attached to the executed
- file.</para></listitem>
+ for details. Takes a whitespace
+ separated list of capability names as
+ read by
+ <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ Capabilities listed will be included
+ in the bounding set, all others are
+ removed. If the list of capabilities
+ is prefixed with ~ all but the listed
+ capabilities will be included, the
+ effect of the assignment
+ inverted. Note that this option does
+ not actually set or unset any
+ capabilities in the effective,
+ permitted or inherited capability
+ sets. That's what
+ <varname>Capabilities=</varname> is
+ for. 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.</para></listitem>
</varlistentry>
<varlistentry>
<option>keep-caps-locked</option>,
<option>no-setuid-fixup</option>,
<option>no-setuid-fixup-locked</option>,
- <option>no-setuid-noroot</option> and/or
- <option>no-setuid-noroot-locked</option>.
+ <option>noroot</option> and/or
+ <option>noroot-locked</option>.
</para></listitem>
</varlistentry>
<varlistentry>
- <term><varname>CapabilityBoundingSetDrop=</varname></term>
-
+ <term><varname>Capabilities=</varname></term>
<listitem><para>Controls the
- capability bounding set drop set for
- the executed process. See
<citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
- for details. Takes a list of
- capability names as read by
- <citerefentry><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
- </para></listitem>
+ 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>
where "cpu" identifies the kernel
control group controller used, and
<filename>/foo/bar</filename> is the
- control group path. The controller name
- and ":" may be omitted in which case
- the named systemd control group
+ control group path. The controller
+ name and ":" may be omitted in which
+ case the named systemd control group
hierarchy is implied. Alternatively,
the path and ":" may be omitted, in
which case the default control group
path for this unit is implied. This
option may be used to place executed
processes in arbitrary groups in
- arbitrary hierachies -- which can be
- configured externally with additional execution limits. By default
- systemd will place all executed
- processes in separate per-unit control
- groups (named after the unit) in the
- systemd named hierarchy. Since every
- process can be in one group per
- hierarchy only overriding the control group
- path in the named systemd hierarchy
- will disable automatic placement in
- the default group. For details about control
- groups see <ulink
+ arbitrary hierarchies -- which can be
+ configured externally with additional
+ execution limits. By default systemd
+ will place all executed processes in
+ separate per-unit control groups
+ (named after the unit) in the systemd
+ named hierarchy. Since every process
+ can be in one group per hierarchy only
+ overriding the control group path in
+ the named systemd hierarchy will
+ disable automatic placement in the
+ default group. This option is
+ primarily intended to place executed
+ processes in specific paths in
+ specific kernel controller
+ hierarchies. It is however not
+ recommended to manipulate the service
+ control group path in the systemd
+ named hierarchy. For details about
+ control groups see <ulink
url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>ControlGroupModify=</varname></term>
+ <listitem><para>Takes a boolean
+ argument. If true, the control groups
+ created for this unit will be owned by
+ the user specified with
+ <varname>User=</varname> (and the
+ appropriate group), and he/she can create
+ subgroups as well as add processes to
+ the group.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ControlGroupAttribute=</varname></term>
+
+ <listitem><para>Set a specific control
+ group attribute for executed
+ processes, and (if needed) add the the
+ executed processes to a cgroup in the
+ hierarchy of the controller the
+ attribute belongs to. Takes two
+ space-separated arguments: the
+ attribute name (syntax is
+ <literal>cpu.shares</literal> where
+ <literal>cpu</literal> refers to a
+ specific controller and
+ <literal>shares</literal> to the
+ attribute name), and the attribute
+ value. Example:
+ <literal>ControlGroupAttribute=cpu.shares
+ 512</literal>. If this option is used
+ for an attribute that belongs to a
+ kernel controller hierarchy the unit
+ is not already configured to be added
+ to (for example via the
+ <literal>ControlGroup=</literal>
+ option) then the unit will be added to
+ the controller and the default unit
+ cgroup path is implied. Thus, using
+ <varname>ControlGroupAttribute=</varname>
+ is in most case sufficient to make use
+ of control group enforcements,
+ explicit
+ <varname>ControlGroup=</varname> are
+ only necessary in case the implied
+ default control group path for a
+ service is not desirable. For details
+ about control group attributes see
+ <ulink
+ url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink>. This
+ option may appear more than once, in
+ order to set multiple control group
+ attributes.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>CPUShares=</varname></term>
+
+ <listitem><para>Assign the specified
+ overall CPU time shares to the
+ processes executed. Takes an integer
+ value. This controls the
+ <literal>cpu.shares</literal> control
+ group attribute, which defaults to
+ 1024. For details about this control
+ group attribute see <ulink
+ url="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>MemoryLimit=</varname></term>
+ <term><varname>MemorySoftLimit=</varname></term>
+
+ <listitem><para>Limit the overall memory usage
+ of the executed processes to a certain
+ size. Takes a memory size in bytes. If
+ the value is suffixed with K, M, G or
+ T the specified memory size is parsed
+ as Kilobytes, Megabytes, Gigabytes,
+ resp. Terabytes (to the base
+ 1024). This controls the
+ <literal>memory.limit_in_bytes</literal>
+ and
+ <literal>memory.soft_limit_in_bytes</literal>
+ control group attributes. For details
+ about these control group attributes
+ see <ulink
+ url="http://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>DeviceAllow=</varname></term>
+ <term><varname>DeviceDeny=</varname></term>
+
+ <listitem><para>Control access to
+ specific device nodes by the executed processes. Takes two
+ space separated strings: a device node
+ path (such as
+ <filename>/dev/null</filename>)
+ followed by a combination of r, w, m
+ to control reading, writing resp.
+ creating of the specific device node
+ by the unit. This controls the
+ <literal>devices.allow</literal>
+ and
+ <literal>devices.deny</literal>
+ control group attributes. For details
+ about these control group attributes
+ see <ulink
+ url="http://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>BlockIOWeight=</varname></term>
+
+ <listitem><para>Set the default or
+ per-device overall block IO weight
+ value for the executed
+ processes. Takes either a single
+ weight value (between 10 and 1000) to
+ set the default block IO weight, or a
+ space separated pair of a file path
+ and a weight value to specify the
+ device specific weight value (Example:
+ "/dev/sda 500"). The file path may be
+ specified as path to a block device
+ node or as any other file in which
+ case the backing block device of the
+ file system of the file is
+ determined. This controls the
+ <literal>blkio.weight</literal> and
+ <literal>blkio.weight_device</literal>
+ control group attributes, which
+ default to 1000. Use this option
+ multiple times to set weights for
+ multiple devices. For details about
+ these control group attributes see
+ <ulink
+ url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>BlockIOReadBandwidth=</varname></term>
+ <term><varname>BlockIOWriteBandwidth=</varname></term>
+
+ <listitem><para>Set the per-device
+ overall block IO bandwith limit for
+ the executed processes. Takes a space
+ separated pair of a file path and a
+ bandwith value (in bytes per second)
+ to specify the device specific
+ bandwidth. The file path may be
+ specified as path to a block device
+ node or as any other file in which
+ case the backing block device of the
+ file system of the file is determined.
+ If the bandwith is suffixed with K, M,
+ G, or T the specified bandwith is
+ parsed as Kilobytes, Megabytes,
+ Gigabytes, resp. Terabytes (Example:
+ "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
+ 5M"). This controls the
+ <literal>blkio.read_bps_device</literal>
+ and
+ <literal>blkio.write_bps_device</literal>
+ control group attributes. Use this
+ option multiple times to set bandwith
+ limits for multiple devices. For
+ details about these control group
+ attributes see <ulink
+ url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>ReadWriteDirectories=</varname></term>
<term><varname>ReadOnlyDirectories=</varname></term>
usual file access controls would
permit this. Directories listed in
<varname>InaccessibleDirectories=</varname>
- will be made inaccesible for processes
+ will be made inaccessible for processes
inside the namespace. Note that
restricting access with these options
does not extend to submounts of a
<term><varname>PrivateTmp=</varname></term>
<listitem><para>Takes a boolean
- argument. If true sets up a new
- namespace for the executed processes
- and mounts a private
+ argument. If true sets up a new file
+ system namespace for the executed
+ processes and mounts a private
<filename>/tmp</filename> directory
inside it, that is not shared by
processes outside of the
process, but makes sharing between
processes via
<filename>/tmp</filename>
- impossible. Defaults to false.</para></listitem>
+ impossible. Defaults to
+ false.</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.</para></listitem>
</varlistentry>
<varlistentry>
~ianmdlvl / elogind.git / blobdiff