chiark / gitweb /
nspawn: introduce --capability=all for retaining all capabilities
[elogind.git] / man / systemd-nspawn.xml
index c2be6d5446babde16ca2ddb4dbc169d65cd5ff2e..ba2c5a487b693270d03d7d2646c227278b400aca 100644 (file)
                 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>
 
                                 <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>
 
                                 </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>--uuid=</option></term>
 
                                 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>
+                                CAP_AUDIT_WRITE, CAP_AUDIT_CONTROL. 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>
                                 creates read-only bind
                                 mount.</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>-q</option></term>
+                                <term><option>--quiet</option></term>
+
+                                <listitem><para>Turns off any status
+                                output by the tool itself. When this
+                                switch is used, then the only output
+                                by nspawn will be the console output
+                                of the container OS itself.</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 in
+                                <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 an 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>
+
                 </variablelist>
 
         </refsect1>
                 boots an OS in a namespace container in it.</para>
         </refsect1>
 
+        <refsect1>
+                <title>Example 4</title>
+
+                <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>
+
+        <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>