Configuring QNAP LXC containers for VPNs using TUN

Published 2018-06-24

Setting up a QNAP NAS as a VPN client is easy, but setting its containers up for VPNs is harder.

Configuring the QNAP device

The first step is to SSH into your QNAP device using the admin account.

ssh admin@NAS_IP
cat >> /share/Container/container-station-data/lib/lxc/CONTAINER_NAME/config << EOF
lxc.cgroup.devices.allow = c 10:200 rwm
EOF

Configuring the container guest

The second step is open the QNAP web-ui, open the Container Station application and enter the console of your container.

sed -i '/exit 0/d' /etc/rc.local
cat >> /etc/rc.local << EOF
if ! [ -c /dev/net/tun ]; then
    mkdir -p /dev/net
    mknod -m 666 /dev/net/tun c 10 200
fi

exit 0
EOF

Lastly the container needs to be restarted, and then your VPN application should be able to access TUN devices and work normally.