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><command>systemd-nspawn</command> may be used to
run a command or OS in a light-weight namespace
container. In many ways it is similar to
- <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
but more powerful since it fully virtualizes the file
system hierarchy, as well as the process tree, the
various IPC subsystems and the host and domain
involved with boot and systems management.</para>
<para>In contrast to
- <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command>
+ <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry> <command>systemd-nspawn</command>
may be used to boot full Linux-based operating systems
in a container.</para>
<para>Use a tool like
- <citerefentry><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
or
- <citerefentry><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ <citerefentry project='arch'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>
to set up an OS directory tree suitable as file system
hierarchy for <command>systemd-nspawn</command>
containers.</para>
<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>
additional capabilities to grant the
container. Takes a comma-separated
list of capability names, see
- <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
for more information. Note that the
following capabilities will be granted
in any way: CAP_CHOWN,
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>
+ <term><option>--drop-capability=</option></term>
+
+ <listitem><para>Specify one or more
+ additional capabilities to drop for
+ the container. This allows running the
+ container with fewer capabilities than
+ the default (see above).</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 project='man-pages'><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>
</para>
</refsect1>
+ <refsect1>
+ <title>Example 5</title>
+
+ <programlisting># btrfs subvolume snapshot / /.tmp
+# systemd-nspawn --private-network -D /.tmp -b</programlisting>
+
+ <para>This runs a copy of the host system in a
+ 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>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='arch'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
~ianmdlvl / elogind.git / blobdiff