along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
-<refentry id="systemd-nspawn">
+<refentry id="systemd-nspawn"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>systemd-nspawn</title>
<para>As a safety check
<command>systemd-nspawn</command> will verify the
- existence of <filename>/etc/os-release</filename> in
- the container tree before starting the container (see
+ existence of <filename>/usr/lib/os-release</filename>
+ or <filename>/etc/os-release</filename> in the
+ container tree before starting the container (see
<citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>). It
might be necessary to add this file to the container
tree manually if the OS of the container is too old to
contain this file out-of-the-box.</para>
</refsect1>
- <refsect1>
- <title>Incompatibility with Auditing</title>
-
- <para>Note that the kernel auditing subsystem is
- currently broken when used together with
- containers. We hence recommend turning it off entirely
- by booting with <literal>audit=0</literal> on the
- kernel command line, or by turning it off at kernel
- build time. If auditing is enabled in the kernel,
- operating systems booted in an nspawn container might
- refuse log-in attempts.</para>
- </refsect1>
-
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
- <varlistentry>
- <term><option>-h</option></term>
- <term><option>--help</option></term>
-
- <listitem><para>Prints a short help
- text and exits.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--version</option></term>
-
- <listitem><para>Prints a version string
- and exits.</para></listitem>
- </varlistentry>
-
<varlistentry>
<term><option>-D</option></term>
<term><option>--directory=</option></term>
<listitem><para>Directory to use as
- file system root for the namespace
- container. If omitted, the current
- directory will be
- used.</para></listitem>
+ file system root for the container. If
+ neither <option>--directory=</option>
+ nor <option>--image=</option> are
+ specified, the current directory will
+ be used. May not be specified together with
+ <option>--image=</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-i</option></term>
+ <term><option>--image=</option></term>
+
+ <listitem><para>Disk image to mount
+ the root directory for the container
+ from. Takes a path to a regular file
+ or to a block device node. The file or
+ block device must contain a GUID
+ Partition Table with a root partition
+ which is mounted as the root directory
+ of the container. Optionally, it may
+ contain a home and/or a server data
+ partition which are mounted to the
+ appropriate places in the
+ container. All these partitions must
+ be identified by the partition types
+ defined by the <ulink
+ url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
+ Partitions Specification</ulink>. Any
+ other partitions, such as foreign
+ partitions, swap partitions or EFI
+ system partitions are not mounted. May
+ not be specified together with
+ <option>--directory=</option>.</para></listitem>
</varlistentry>
<varlistentry>
<listitem><para>Automatically search
for an init binary and invoke it
instead of a shell or a user supplied
- program. If this option is used, arguments
- specified on the command line are used
- as arguments for the init binary.
+ program. If this option is used,
+ arguments specified on the command
+ line are used as arguments for the
+ init binary. This option may not be
+ combined with
+ <option>--share-system</option>.
</para></listitem>
</varlistentry>
<term><option>-u</option></term>
<term><option>--user=</option></term>
- <listitem><para>Run the command
- under specified user, create home
- directory and cd into it. As rest
- of systemd-nspawn, this is not
- the security feature and limits
- against accidental changes only.
- </para></listitem>
+ <listitem><para>After transitioning
+ into the container, change to the
+ specified user-defined in the
+ container's user database. Like all
+ other systemd-nspawn features, this is
+ not a security feature and provides
+ protection against accidental
+ destructive operations
+ only.</para></listitem>
</varlistentry>
<varlistentry>
container is used.</para></listitem>
</varlistentry>
- <varlistentry>
- <term><option>--slice=</option></term>
-
- <listitem><para>Make the container
- part of the specified slice, instead
- of the
- <filename>machine.slice</filename>.</para>
- </listitem>
- </varlistentry>
-
<varlistentry>
<term><option>--uuid=</option></term>
</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>--slice=</option></term>
+
+ <listitem><para>Make the container
+ part of the specified slice, instead
+ of the default
+ <filename>machine.slice</filename>.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>--private-network</option></term>
- <listitem><para>Turn off networking in
- the container. This makes all network
- interfaces unavailable in the
- container, with the exception of the
- loopback device.</para></listitem>
+ <listitem><para>Disconnect networking
+ of the container from the host. This
+ makes all network interfaces
+ unavailable in the container, with the
+ exception of the loopback device and
+ those specified with
+ <option>--network-interface=</option>
+ and configured with
+ <option>--network-veth</option>. If
+ this option is specified, the
+ CAP_NET_ADMIN capability will be added
+ to the set of capabilities the
+ container retains. The latter may be
+ disabled by using
+ <option>--drop-capability=</option>.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--read-only</option></term>
+ <term><option>--network-interface=</option></term>
+
+ <listitem><para>Assign the specified
+ network interface to the
+ container. This will remove the
+ specified interface from the calling
+ namespace and place it in the
+ container. When the container
+ terminates, it is moved back to the
+ host namespace. Note that
+ <option>--network-interface=</option>
+ implies
+ <option>--private-network</option>. This
+ option may be used more than once to
+ add multiple network interfaces to the
+ container.</para></listitem>
+ </varlistentry>
- <listitem><para>Mount the root file
- system read-only for the
+ <varlistentry>
+ <term><option>--network-macvlan=</option></term>
+
+ <listitem><para>Create a
+ <literal>macvlan</literal> interface
+ of the specified Ethernet network
+ interface and add it to the
+ container. A
+ <literal>macvlan</literal> interface
+ is a virtual interface that adds a
+ second MAC address to an existing
+ physical Ethernet link. The interface
+ in the container will be named after
+ the interface on the host, prefixed
+ with <literal>mv-</literal>. Note that
+ <option>--network-macvlan=</option>
+ implies
+ <option>--private-network</option>. This
+ option may be used more than once to
+ add multiple network interfaces to the
container.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>--network-veth</option></term>
+
+ <listitem><para>Create a virtual
+ Ethernet link
+ (<literal>veth</literal>) between host
+ and container. The host side of the
+ Ethernet link will be available as a
+ network interface named after the
+ container's name (as specified with
+ <option>--machine=</option>), prefixed
+ with <literal>ve-</literal>. The
+ container side of the Ethernet
+ link will be named
+ <literal>host0</literal>. Note that
+ <option>--network-veth</option>
+ implies
+ <option>--private-network</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--network-bridge=</option></term>
+
+ <listitem><para>Adds the host side of
+ the Ethernet link created with
+ <option>--network-veth</option> to the
+ specified bridge. Note that
+ <option>--network-bridge=</option>
+ implies
+ <option>--network-veth</option>. If
+ this option is used, the host side of
+ the Ethernet link will use the
+ <literal>vb-</literal> prefix instead
+ of <literal>ve-</literal>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-Z</option></term>
+ <term><option>--selinux-context=</option></term>
+
+ <listitem><para>Sets the SELinux
+ security context to be used to label
+ processes in the container.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>-L</option></term>
+ <term><option>--selinux-apifs-context=</option></term>
+
+ <listitem><para>Sets the SELinux security
+ context to be used to label files in
+ the virtual API file systems in the
+ container.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>--capability=</option></term>
CAP_SYS_PTRACE, CAP_SYS_TTY_CONFIG,
CAP_SYS_RESOURCE, CAP_SYS_BOOT,
CAP_AUDIT_WRITE,
- CAP_AUDIT_CONTROL.</para></listitem>
+ CAP_AUDIT_CONTROL. Also CAP_NET_ADMIN
+ is retained if
+ <option>--private-network</option> is
+ specified. If the special value
+ <literal>all</literal> is passed, all
+ capabilities are
+ retained.</para></listitem>
</varlistentry>
<varlistentry>
<option>--link-journal=guest</option>.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>--read-only</option></term>
+
+ <listitem><para>Mount the root file
+ system read-only for the
+ container.</para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>--bind=</option></term>
<term><option>--bind-ro=</option></term>
destination in the container. The
<option>--bind-ro=</option> option
creates read-only bind
- mount.</para></listitem>
+ mounts.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--tmpfs=</option></term>
+
+ <listitem><para>Mount a tmpfs file
+ system into the container. Takes a
+ single absolute path argument that
+ specifies where to mount the tmpfs
+ instance to (in which case the
+ directory access mode will be chosen
+ as 0755, owned by root/root), or
+ optionally a colon-separated pair of
+ path and mount option string, that is
+ used for mounting (in which case the
+ kernel default for access mode and
+ owner will be chosen, unless otherwise
+ specified). This option is
+ particularly useful for mounting
+ directories such as
+ <filename>/var</filename> as tmpfs, to
+ allow state-less systems, in
+ particular when combined with
+ <option>--read-only</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--setenv=</option></term>
+
+ <listitem><para>Specifies an
+ environment variable assignment to
+ pass to the init process in the
+ container, in the format
+ <literal>NAME=VALUE</literal>. This
+ may be used to override the default
+ variables or to set additional
+ variables. This parameter may be used
+ more than once.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--share-system</option></term>
+
+ <listitem><para>Allows the container
+ to share certain system facilities
+ with the host. More specifically, this
+ turns off PID namespacing, UTS
+ namespacing and IPC namespacing, and
+ thus allows the guest to see and
+ interact more easily with processes
+ outside of the container. Note that
+ using this option makes it impossible
+ to start up a full Operating System in
+ the container, as an init system
+ cannot operate in this mode. It is
+ only useful to run specific programs
+ or applications this way, without
+ involving an init system in the
+ container. This option implies
+ <option>--register=no</option>. This
+ option may not be combined with
+ <option>--boot</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--register=</option></term>
+
+ <listitem><para>Controls whether the
+ container is registered with
+ <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Takes
+ a boolean argument, defaults to
+ <literal>yes</literal>. This option
+ should be enabled when the container
+ runs a full Operating System (more
+ specifically: an init system), and is
+ useful to ensure that the container is
+ accessible via
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ and shown by tools such as
+ <citerefentry><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry>. If
+ the container does not run an init
+ system, it is recommended to set this
+ option to <literal>no</literal>. Note
+ that <option>--share-system</option>
+ implies
+ <option>--register=no</option>.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--keep-unit</option></term>
+
+ <listitem><para>Instead of creating a
+ transient scope unit to run the
+ container in, simply register the
+ service or scope unit
+ <command>systemd-nspawn</command> has
+ been invoked in with
+ <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This
+ has no effect if
+ <option>--register=no</option> is
+ used. This switch should be used if
+ <command>systemd-nspawn</command> is
+ invoked from within a service unit,
+ and the service unit's sole purpose
+ is to run a single
+ <command>systemd-nspawn</command>
+ container. This option is not
+ available if run from a user
+ session.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--personality=</option></term>
+
+ <listitem><para>Control the
+ architecture ("personality") reported
+ by
+ <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ in the container. Currently, only
+ <literal>x86</literal> and
+ <literal>x86-64</literal> are
+ supported. This is useful when running
+ a 32-bit container on a 64-bit
+ host. If this setting is not used,
+ the personality reported in the
+ container is the same as the one
+ reported on the
+ host.</para></listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><option>-q</option></term>
+ <term><option>--quiet</option></term>
+
+ <listitem><para>Turns off any status
+ output by the tool itself. When this
+ switch is used, the only output
+ from nspawn will be the console output
+ of the container OS itself.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--volatile</option><replaceable>=MODE</replaceable></term>
+
+ <listitem><para>Boots the container in
+ volatile (ephemeral) mode. When no
+ mode parameter is passed or when mode
+ is specified as <literal>yes</literal>
+ full volatile mode is enabled. This
+ means the root directory is mounted as
+ mostly unpopulated
+ <literal>tmpfs</literal> instance, and
+ <filename>/usr</filename> from the OS
+ tree is mounted into it, read-only
+ (the system thus starts up with
+ read-only OS resources, but pristine
+ state and configuration, any changes
+ to the either are lost on
+ shutdown). When the mode parameter is
+ specified as <literal>state</literal>
+ the OS tree is mounted read-only, but
+ <filename>/var</filename> is mounted
+ as <literal>tmpfs</literal> instance
+ into it (the system thus starts up
+ with read-only OS resources and
+ configuration, but prestine state, any
+ changes to the latter are lost on
+ shutdown). When the mode parameter is
+ specified as <literal>no</literal>
+ (the default) the whole OS tree is made
+ available writable.</para>
+
+ <para>Note that setting this to
+ <literal>yes</literal> or
+ <literal>state</literal> will only
+ work correctly with operating systems
+ in the container that can boot up with
+ only <filename>/usr</filename>
+ mounted, and are able to populate
+ <filename>/var</filename>
+ automatically, as
+ needed.</para></listitem>
+ </varlistentry>
+
+ <xi:include href="standard-options.xml" xpointer="help" />
+ <xi:include href="standard-options.xml" xpointer="version" />
</variablelist>
</refsect1>
btrfs snapshot.</para>
</refsect1>
+ <refsect1>
+ <title>Example 6</title>
+
+ <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container
+# systemd-nspawn -L system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -Z system_u:system_r:svirt_lxc_net_t:s0:c0,c1 -D /srv/container /bin/sh</programlisting>
+
+ <para>This runs a container with SELinux sandbox security contexts.</para>
+ </refsect1>
<refsect1>
<title>Exit status</title>