<!DOCTYPE refentry PUBLIC @docdtd@ [

<!ENTITY commonoptions SYSTEM "@builddir@/common_options.sgml">

<!ENTITY seealso SYSTEM "@builddir@/see_also.sgml">

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<refentry>

<docinfo><date>@LXC_GENERATE_DATE@</date></docinfo>

<refmeta>

<refentrytitle>lxc-unshare</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>lxc-unshare</refname>

<refpurpose>

Run a task in a new set of namespaces.

</refpurpose>

</refnamediv>

<refsynopsisdiv>

<cmdsynopsis>

<command>lxc-unshare</command>

<arg choice="req">-s <replaceable>namespaces</replaceable></arg>

<arg choice="opt">-u <replaceable>user</replaceable></arg>

<arg choice="opt">-H <replaceable>hostname</replaceable></arg>

<arg choice="opt">-i <replaceable>ifname</replaceable></arg>

<arg choice="opt">-d</arg>

<arg choice="opt">-M</arg>

<arg choice="req">command</arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para>

<command>lxc-unshare</command> can be used to run a task in a cloned set

of namespaces. This command is mainly provided for testing purposes.

Despite its name, it always uses clone rather than unshare to create

the new task with fresh namespaces. Apart from testing kernel

regressions this should make no difference.

</para>

</refsect1>

<refsect1>

<title>Options</title>

<variablelist>

<varlistentry>

<term>

<option>-s <replaceable>namespaces</replaceable></option>

</term>

<listitem>

<para>

Specify the namespaces to attach to, as a pipe-separated list,

e.g. <replaceable>NETWORK|IPC</replaceable>. Allowed values are

<replaceable>MOUNT</replaceable>, <replaceable>PID</replaceable>,

<replaceable>UTSNAME</replaceable>, <replaceable>IPC</replaceable>,

<replaceable>USER </replaceable> and

<replaceable>NETWORK</replaceable>. This allows one to change

the context of the process to e.g. the network namespace of the

container while retaining the other namespaces as those of the

host. (The pipe symbol needs to be escaped, e.g.

<replaceable>MOUNT\|PID</replaceable> or quoted, e.g.

<replaceable>"MOUNT|PID"</replaceable>.)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>-u <replaceable>user</replaceable></option>

</term>

<listitem>

<para>

Specify a userid which the new task should become.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>-H <replaceable>hostname</replaceable></option>

</term>

<listitem>

<para>

Set the hostname in the new container. Only allowed if

the UTSNAME namespace is set.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>-i <replaceable>interfacename</replaceable></option>

</term>

<listitem>

<para>

Move the named interface into the container. Only allowed

if the NETWORK namespace is set. You may specify this

argument multiple times to move multiple interfaces into

container.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>-d</option>

</term>

<listitem>

<para>

Daemonize (do not wait for the container to exit before exiting)

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>-M</option>

</term>

<listitem>

<para>

Mount default filesystems (/proc /dev/shm and /dev/mqueue)

in the container. Only allowed if MOUNT namespace is set.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Examples</title>

<para>

To spawn a new shell with its own UTS (hostname) namespace,

<programlisting>

lxc-unshare -s UTSNAME /bin/bash

</programlisting>

If the hostname is changed in that shell, the change will not be

reflected on the host.

</para>

<para>

To spawn a shell in a new network, pid, and mount namespace,

<programlisting>

lxc-unshare -s "NETWORK|PID|MOUNT" /bin/bash

</programlisting>

The resulting shell will have pid 1 and will see no network interfaces.

After re-mounting /proc in that shell,

<programlisting>

mount -t proc proc /proc

</programlisting>

ps output will show there are no other processes in the namespace.

</para>

<para>

To spawn a shell in a new network, pid, mount, and hostname

namespace.

<programlisting>

lxc-unshare -s "NETWORK|PID|MOUNT|UTSNAME" -M -H slave -i veth1 /bin/bash

</programlisting>

The resulting shell will have pid 1 and will see two network

interfaces (lo and veth1). The hostname will be "slave" and

/proc will have been remounted. ps output will show there are

no other processes in the namespace.

</para>

</refsect1>

&seealso;

<refsect1>

<title>Author</title>

<para>Daniel Lezcano <email>daniel.lezcano@free.fr</email></para>

</refsect1>

</refentry>