audit: since audit is apparently never going to be fixed for containers tell the...

[elogind.git] / man / systemd-nspawn.xml

diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index 667e75c2cd70dd131c0572ce0bef4bdd517276ca..1bc61e83a76b048e3f27582a30fc30e4aed65fbc 100644 (file)
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -8,16 +8,16 @@
   Copyright 2010 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
   Copyright 2010 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it

-  under the terms of the GNU General Public License as published by
-  the Free Software Foundation; either version 2 of the License, or
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or

   (at your option) any later version.
 
   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   (at your option) any later version.
 
   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

-  General Public License for more details.
+  Lesser General Public License for more details.

 
 

-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License

   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 


@@ -49,7 +49,17 @@
 
         <refsynopsisdiv>
                 <cmdsynopsis>
 
         <refsynopsisdiv>
                 <cmdsynopsis>

-                        <command>systemd-nspawn <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">COMMAND</arg> <arg choice="opt" rep="repeat">ARGS</arg></command>
+                        <command>systemd-nspawn</command>
+                        <arg choice="opt" rep="repeat">OPTIONS</arg>
+                        <arg choice="opt"><replaceable>COMMAND</replaceable>
+                        <arg choice="opt" rep="repeat">ARGS</arg>
+                        </arg>
+                </cmdsynopsis>
+                <cmdsynopsis>
+                        <command>systemd-nspawn</command>
+                        <arg choice="plain">-b</arg>
+                        <arg choice="opt" rep="repeat">OPTIONS</arg>
+                        <arg choice="opt" rep="repeat">ARGS</arg>

                 </cmdsynopsis>
         </refsynopsisdiv>
 
                 </cmdsynopsis>
         </refsynopsisdiv>
 


@@ -61,7 +71,7 @@
                 container. In many ways it is similar to
                 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                 but more powerful since it fully virtualizes the file
                 container. In many ways it is similar to
                 <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                 but more powerful since it fully virtualizes the file

-                system hierachy, as well as the process tree, the
+                system hierarchy, as well as the process tree, the

                 various IPC subsystems and the host and domain
                 name.</para>
 
                 various IPC subsystems and the host and domain
                 name.</para>
 


@@ -69,11 +79,12 @@
                 to various kernel interfaces in the container to
                 read-only, such as <filename>/sys</filename>,
                 <filename>/proc/sys</filename> or
                 to various kernel interfaces in the container to
                 read-only, such as <filename>/sys</filename>,
                 <filename>/proc/sys</filename> or

-                <filename>/selinux</filename>. Network interfaces and
-                the system clock may not be changed from within the
-                container. Device nodes may not be created. The host
-                system cannot be rebooted and kernel modules may not
-                be loaded from within the container.</para>
+                <filename>/sys/fs/selinux</filename>. Network
+                interfaces and the system clock may not be changed
+                from within the container. Device nodes may not be
+                created. The host system cannot be rebooted and kernel
+                modules may not be loaded from within the
+                container.</para>

 
                 <para>Note that even though these security precautions
                 are taken <command>systemd-nspawn</command> is not
 
                 <para>Note that even though these security precautions
                 are taken <command>systemd-nspawn</command> is not


@@ -92,9 +103,13 @@
                 container.</para>
 
                 <para>Use a tool like
                 container.</para>
 
                 <para>Use a tool like

-                <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry> or <citerefentry><refentrytitle>mock</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+                <citerefentry><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+                or
+                <citerefentry><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>

                 to set up an OS directory tree suitable as file system
                 to set up an OS directory tree suitable as file system

-                hierarchy for <command>systemd-nspawn</command> containers.</para>
+                hierarchy for <command>systemd-nspawn</command>
+                containers.</para>

 
                 <para>Note that <command>systemd-nspawn</command> will
                 mount file systems private to the container to
 
                 <para>Note that <command>systemd-nspawn</command> will
                 mount file systems private to the container to


@@ -106,22 +121,59 @@
                 <para>Note that running two
                 <command>systemd-nspawn</command> containers from the
                 same directory tree will not make processes in them
                 <para>Note that running two
                 <command>systemd-nspawn</command> containers from the
                 same directory tree will not make processes in them

-                see each other. The PID namespace seperation of the
+                see each other. The PID namespace separation of the

                 two containers is complete and the containers will
                 share very few runtime objects except for the
                 two containers is complete and the containers will
                 share very few runtime objects except for the

-                underlying file system.</para>
+                underlying file system. It is however possible to
+                enter an existing container, see
+                <link linkend='example-nsenter'>Example 4</link> below.
+                </para>
+
+                <para><command>systemd-nspawn</command> implements the
+                <ulink
+                url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container
+                Interface</ulink> specification.</para>
+
+                <para>As a safety check
+                <command>systemd-nspawn</command> will verify the
+                existance of <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>
 
         </refsect1>
 
         <refsect1>
                 <title>Options</title>
 

-                <para>If no arguments are passed the container is set
-                up and a shell started in it, otherwise the passed
-                command and arguments are executed in it. The
-                following options are understood:</para>
+                <para>If option <option>-b</option> is specified, the
+                arguments are used as arguments for the init
+                binary. Otherwise, <replaceable>COMMAND</replaceable>
+                specifies the program to launch in the container, and
+                the remaining arguments are used as arguments for this
+                program. If <option>-b</option> is not used and no
+                arguments are specifed, a shell is launched in the
+                container.</para>
+
+                <para>The following options are understood:</para>

 
                 <variablelist>
                         <varlistentry>
 
                 <variablelist>
                         <varlistentry>

+                                <term><option>-h</option></term>

                                 <term><option>--help</option></term>
 
                                 <listitem><para>Prints a short help
                                 <term><option>--help</option></term>
 
                                 <listitem><para>Prints a short help


@@ -129,8 +181,15 @@
                         </varlistentry>
 
                         <varlistentry>
                         </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>
                                 <term><option>--directory=</option></term>

-                                <term><option>--D</option></term>

 
                                 <listitem><para>Directory to use as
                                 file system root for the namespace
 
                                 <listitem><para>Directory to use as
                                 file system root for the namespace


@@ -139,6 +198,179 @@
                                 used.</para></listitem>
                         </varlistentry>
 
                                 used.</para></listitem>
                         </varlistentry>
 

+                        <varlistentry>
+                                <term><option>-b</option></term>
+                                <term><option>--boot</option></term>
+
+                                <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.
+                                </para></listitem>
+                        </varlistentry>
+
+                        <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>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>-M</option></term>
+                                <term><option>--machine=</option></term>
+
+                                <listitem><para>Sets the machine name
+                                for this container. This name may be
+                                used to identify this container on the
+                                host, and is used to initialize the
+                                container's hostname (which the
+                                container can choose to override,
+                                however). If not specified the last
+                                component of the root directory of the
+                                container is used.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>--uuid=</option></term>
+
+                                <listitem><para>Set the specified uuid
+                                for the container. The init system
+                                will initialize
+                                <filename>/etc/machine-id</filename>
+                                from this if this file is not set yet.
+                                </para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>-C</option></term>
+                                <term><option>--controllers=</option></term>
+
+                                <listitem><para>Makes the container appear in
+                                other hierarchies than the name=systemd:/ one.
+                                Takes a comma-separated list of controllers.
+                                </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>
+                        </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>--capability=</option></term>
+
+                                <listitem><para>List one or more
+                                additional capabilities to grant the
+                                container. Takes a comma separated
+                                list of capability names, see
+                                <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                                for more information. Note that the
+                                following capabilities will be granted
+                                in any way: CAP_CHOWN,
+                                CAP_DAC_OVERRIDE, CAP_DAC_READ_SEARCH,
+                                CAP_FOWNER, CAP_FSETID, CAP_IPC_OWNER,
+                                CAP_KILL, CAP_LEASE,
+                                CAP_LINUX_IMMUTABLE,
+                                CAP_NET_BIND_SERVICE,
+                                CAP_NET_BROADCAST, CAP_NET_RAW,
+                                CAP_SETGID, CAP_SETFCAP, CAP_SETPCAP,
+                                CAP_SETUID, CAP_SYS_ADMIN,
+                                CAP_SYS_CHROOT, CAP_SYS_NICE,
+                                CAP_SYS_PTRACE, CAP_SYS_TTY_CONFIG,
+                                CAP_SYS_RESOURCE, CAP_SYS_BOOT,
+                                CAP_AUDIT_WRITE,
+                                CAP_AUDIT_CONTROL.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>--link-journal=</option></term>
+
+                                <listitem><para>Control whether the
+                                container's journal shall be made
+                                visible to the host system. If enabled
+                                allows viewing the container's journal
+                                files from the host (but not vice
+                                versa). Takes one of
+                                <literal>no</literal>,
+                                <literal>host</literal>,
+                                <literal>guest</literal>,
+                                <literal>auto</literal>. If
+                                <literal>no</literal>, the journal is
+                                not linked. If <literal>host</literal>,
+                                the journal files are stored on the
+                                host file system (beneath
+                                <filename>/var/log/journal/<replaceable>machine-id</replaceable></filename>)
+                                and the subdirectory is bind-mounted
+                                into the container at the same
+                                location. If <literal>guest</literal>,
+                                the journal files are stored on the
+                                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),
+                                and the right subdirectory of
+                                <filename>/var/log/journal</filename>
+                                exists, it will be bind mounted
+                                into the container. If the
+                                subdirectory doesn't exist, no
+                                linking is performed. Effectively,
+                                booting a container once with
+                                <literal>guest</literal> or
+                                <literal>host</literal> will link the
+                                journal persistently if further on
+                                the default of <literal>auto</literal>
+                                is used.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>-j</option></term>
+
+                                <listitem><para>Equivalent to
+                                <option>--link-journal=guest</option>.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term><option>--bind=</option></term>
+                                <term><option>--bind-ro=</option></term>
+
+                                <listitem><para>Bind mount a file or
+                                directory from the host into the
+                                container. Either takes a path
+                                argument -- in which case the
+                                specified path will be mounted from
+                                the host to the same path in the
+                                container --, or a colon-separated
+                                pair of paths -- in which case the
+                                first specified path is the source in
+                                the host, and the second path is the
+                                destination in the container. The
+                                <option>--bind-ro=</option> option
+                                creates read-only bind
+                                mount.</para></listitem>
+                        </varlistentry>

                 </variablelist>
 
         </refsect1>
                 </variablelist>
 
         </refsect1>


@@ -146,28 +378,54 @@
         <refsect1>
                 <title>Example 1</title>
 
         <refsect1>
                 <title>Example 1</title>
 

-                <programlisting># debootstrap --arch=amd64 unstable debian-tree/
-# systemd-nspawn -D debian-tree/</programlisting>
+                <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>
+
+        <refsect1>
+                <title>Example 2</title>
+
+                <programlisting># debootstrap --arch=amd64 unstable ~/debian-tree/
+# systemd-nspawn -D ~/debian-tree/</programlisting>

 
                 <para>This installs a minimal Debian unstable
                 distribution into the directory
 
                 <para>This installs a minimal Debian unstable
                 distribution into the directory

-                <filename>debian-tree/</filename> and then spawns a
+                <filename>~/debian-tree/</filename> and then spawns a

                 shell in a namespace container in it.</para>
                 shell in a namespace container in it.</para>

-

         </refsect1>
 
         <refsect1>
         </refsect1>
 
         <refsect1>

-                <title>Example 2</title>
+                <title>Example 3</title>

 
 

-                <programlisting># mock --init
-# systemd-nspawn -D /var/lib/mock/fedora-rawhide-x86_64/root/ /bin/systemd systemd.log_level=debug</programlisting>
+                <programlisting># pacstrap -c -d ~/arch-tree/ base
+# systemd-nspawn -bD ~/arch-tree/</programlisting>

 
 

-                <para>This installs a minimal Fedora distribution into
-                a subdirectory of <filename>/var/lib/mock/</filename>
-                and then boots an OS in a namespace container in it,
-                with systemd as init system, configured for debug
-                logging.</para>
+                <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>
+
+        <refsect1 id='example-nsenter'>
+                <title>Example 4</title>
+
+                <para>To enter the container, PID of one of the
+                processes sharing the new namespaces must be used.
+                <command>systemd-nspawn</command> prints the PID
+                (as viewed from the outside) of the launched process,
+                and it can be used to enter the container.</para>
+
+                <programlisting># nsenter -m -u -i -n -p -t $PID</programlisting>

 
 

+                <para><citerefentry><refentrytitle>nsenter</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+                is part of
+                <ulink url="https://github.com/karelzak/util-linux">util-linux</ulink>.
+                Kernel support for entering namespaces was added in
+                Linux 3.8.</para>

         </refsect1>
 
         <refsect1>
         </refsect1>
 
         <refsect1>


@@ -182,8 +440,10 @@
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

-                        <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>
-                        <citerefentry><refentrytitle>mock</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>unshare</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>

                 </para>
         </refsect1>
 
                 </para>
         </refsect1>