man/shutdown: /etc/nologin is called /run/nologin now

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

diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index 554637d5f1919b0fc223860a3e47fe854c42fffb..8adcd946b0438e6da634576eefc780a99ada068a 100644 (file)
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -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>
 


@@ -114,7 +124,10 @@
                 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
                 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

-                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
 
                 <para><command>systemd-nspawn</command> implements the
                 <ulink


@@ -125,15 +138,21 @@
         <refsect1>
                 <title>Options</title>
 
         <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>--help</option></term>

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

+                                <term><option>--help</option></term>

 
                                 <listitem><para>Prints a short help
                                 text and exits.</para></listitem>
 
                                 <listitem><para>Prints a short help
                                 text and exits.</para></listitem>


@@ -147,8 +166,8 @@
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>

-                                <term><option>--directory=</option></term>

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

+                                <term><option>--directory=</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


@@ -158,18 +177,21 @@
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>

-                                <term><option>--boot</option></term>

                                 <term><option>-b</option></term>
                                 <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
 
                                 <listitem><para>Automatically search
                                 for an init binary and invoke it
                                 instead of a shell or a user supplied

-                                program.</para></listitem>
+                                program. If this option is used, arguments
+                                specified on the command line are used
+                                as arguments for the init binary.
+                                </para></listitem>

                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>

-                                <term><option>--user=</option></term>

                                 <term><option>-u</option></term>
                                 <term><option>-u</option></term>

+                                <term><option>--user=</option></term>

 
                                 <listitem><para>Run the command
                                 under specified user, create home
 
                                 <listitem><para>Run the command
                                 under specified user, create home


@@ -192,8 +214,8 @@
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>

-                                <term><option>--controllers=</option></term>

                                 <term><option>-C</option></term>
                                 <term><option>-C</option></term>

+                                <term><option>--controllers=</option></term>

 
                                 <listitem><para>Makes the container appear in
                                 other hierarchies than the name=systemd:/ one.
 
                                 <listitem><para>Makes the container appear in
                                 other hierarchies than the name=systemd:/ one.


@@ -262,13 +284,13 @@
                                 not linked. If <literal>host</literal>,
                                 the journal files are stored on the
                                 host file system (beneath
                                 not linked. If <literal>host</literal>,
                                 the journal files are stored on the
                                 host file system (beneath

-                                <filename>/var/log/journal/&lt;machine-id&gt;</filename>)
+                                <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
                                 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/&lt;machine-id&gt;</filename>)
+                                <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 subdirectory is symlinked into the host
                                 at the same location. If
                                 <literal>auto</literal> (the default),


@@ -292,6 +314,26 @@
                                 <listitem><para>Equivalent to
                                 <option>--link-journal=guest</option>.</para></listitem>
                         </varlistentry>
                                 <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>


@@ -318,7 +360,6 @@
                 distribution into the directory
                 <filename>~/debian-tree/</filename> and then spawns a
                 shell in a namespace container in it.</para>
                 distribution into the directory
                 <filename>~/debian-tree/</filename> and then spawns a
                 shell in a namespace container in it.</para>

-

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


@@ -332,6 +373,24 @@
                 boots an OS in a namespace container in it.</para>
         </refsect1>
 
                 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 -muinpt $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>
                 <title>Exit status</title>
 
         <refsect1>
                 <title>Exit status</title>
 


@@ -344,6 +403,7 @@
                 <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>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>
                         <citerefentry><refentrytitle>yum</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>