Libvirt lxc configurations

userns-with-vpn.xml

<domain type='lxc'>
  <name>vpntest</name>
  <uuid>ffee008c-ec6b-48ab-af6d-4aba830847a1</uuid>
  <memory unit='GiB'>8</memory> <!-- The container can use at most 8G of memory -->
  <idmap>
    <uid start='0' target='300000' count='65536'/>
    <gid start='0' target='300000' count='65536'/>
  </idmap>
  <os>
    <type arch='x86_64'>exe</type>
    <init>/sbin/init</init>
  </os>
  <devices>
    <emulator>/usr/lib/libvirt/libvirt_lxc</emulator>
    <filesystem type='mount' accessmode='passthrough'>
      <source dir='/var/lib/libvirt/lxc/vpntest'/>  <!-- this directory must have uids/gids starting from 300000 -->
      <target dir='/'/>
    </filesystem>
    <filesystem type='mount' accessmode='passthrough'> <!-- passthrough /dev/net/tun from the host -->
      <source dir='/dev/net'/>
      <target dir='/dev/net'/>
    </filesystem>    
    <hostdev mode='capabilities' type='misc'> <!-- give the necessary cgroup permission to access /dev/net/tun -->
      <source>
        <char>/dev/net/tun</char>
      </source>
    </hostdev>
    <interface type='network'>
      <mac address='52:54:00:3e:59:e9'/>
      <source network='default'/>
    </interface>
    <console type='pty'>
      <target type='lxc' port='0'/>
    </console>
  </devices>
</domain>