<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='archlinux'><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>
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,
versa). Takes one of
<literal>no</literal>,
<literal>host</literal>,
+ <literal>try-host</literal>,
<literal>guest</literal>,
+ <literal>try-guest</literal>,
<literal>auto</literal>. If
<literal>no</literal>, the journal is
not linked. If <literal>host</literal>,
guest file system (beneath
<filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>)
and the subdirectory is symlinked into the host
- at the same location. If
- <literal>auto</literal> (the default),
+ at the same location. <literal>try-host</literal>
+ and <literal>try-guest</literal> do the same
+ but do not fail if the host does not have
+ persistant journalling enabled.
+ If <literal>auto</literal> (the default),
and the right subdirectory of
<filename>/var/log/journal</filename>
exists, it will be bind mounted
<term><option>-j</option></term>
<listitem><para>Equivalent to
- <option>--link-journal=guest</option>.</para></listitem>
+ <option>--link-journal=try-guest</option>.</para></listitem>
</varlistentry>
<varlistentry>
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
+ <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
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 pristine 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>
<refsect1>
- <title>Example 1</title>
+ <title>Examples</title>
+ <example>
+ <title>Boot a minimal Fedora distribution in a container</title>
- <programlisting># yum -y --releasever=19 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
+
<programlisting># yum -y --releasever=19 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
# systemd-nspawn -bD /srv/mycontainer</programlisting>
- <para>This installs a minimal Fedora distribution into
- the directory <filename noindex='true'>/srv/mycontainer/</filename> and
- then boots an OS in a namespace container in
- it.</para>
- </refsect1>
+
<para>This installs a minimal Fedora distribution into
+ the directory <filename noindex='true'>/srv/mycontainer/</filename> and
+ then boots an OS in a namespace container in
+ it.</para>
+ </example>
- <refsect1>
- <title>Example 2</title>
+ <example>
+ <title>Spawn a shell in a container of a minimal Debian unstable distribution</title>
- <programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/
+
<programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/
# systemd-nspawn -D ~/debian-tree/</programlisting>
- <para>This installs a minimal Debian unstable
- distribution into the directory
- <filename>~/debian-tree/</filename> and then spawns a
- shell in a namespace container in it.</para>
- </refsect1>
+
<para>This installs a minimal Debian unstable
+ distribution into the directory
+ <filename>~/debian-tree/</filename> and then spawns a
+ shell in a namespace container in it.</para>
+ </example>
- <refsect1>
- <title>Example 3</title>
+ <example>
+ <title>Boot a minimal Arch Linux distribution in a container</title>
- <programlisting># pacstrap -c -d ~/arch-tree/ base
+
<programlisting># pacstrap -c -d ~/arch-tree/ base
# systemd-nspawn -bD ~/arch-tree/</programlisting>
- <para>This installs a mimimal Arch Linux distribution into
- the directory <filename>~/arch-tree/</filename> and then
- boots an OS in a namespace container in it.</para>
- </refsect1>
+
<para>This installs a mimimal Arch Linux distribution into
+ the directory <filename>~/arch-tree/</filename> and then
+ boots an OS in a namespace container in it.</para>
+ </example>
- <refsect1>
- <title>Example 4</title>
+ <example>
+ <title>Enable Arch Linux container on boot</title>
- <programlisting># mv ~/arch-tree /var/lib/container/arch
+
<programlisting># mv ~/arch-tree /var/lib/container/arch
# systemctl enable systemd-nspawn@arch.service
# systemctl start systemd-nspawn@arch.service</programlisting>
- <para>This makes the Arch Linux container part of the
- <filename>multi-user.target</filename> on the host.
- </para>
- </refsect1>
+
<para>This makes the Arch Linux container part of the
+ <filename>multi-user.target</filename> on the host.
+ </para>
+ </example>
- <refsect1>
- <title>Example 5</title>
+ <example>
+ <title>Boot into a btrfs snapshot of the host system</title>
- <programlisting># btrfs subvolume snapshot / /.tmp
+
<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>
+
<para>This runs a copy of the host system in a
+ btrfs snapshot.</para>
+ </example>
- <refsect1>
- <title>Example 6</title>
+ <example>
+ <title>Run a container with SELinux sandbox security contexts</title>
- <programlisting># chcon system_u:object_r:svirt_sandbox_file_t:s0:c0,c1 -R /srv/container
+
<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>
+ </example>
</refsect1>
<refsect1>
<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='archlinux'><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