<para>The files listed with this
directive will be read shortly before
- the process is executed. Settings from
- these files override settings made
- with
+ the process is executed (more
+ specifically, this means 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
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>
may be prefixed with
<literal>-</literal>, in which case
they will be ignored when they do not
- exist.</para></listitem>
+ 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>
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
+ 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.</para></listitem>
+ 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>
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
+ 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.</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. Note that
- enabling this option implies that
- <constant>CAP_MKNOD</constant> is
- removed from the capability bounding
- set for the unit.</para></listitem>
+ 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>
<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
+ 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. Default to
- <option>shared</option>.</para></listitem>
+ 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 continously 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>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>
~ianmdlvl / elogind.git / blobdiff