Proxmox Containers: Manage network interfaces file yourself

Proxmox will manage the network interfaces file (/etc/network/interfaces on Debian) for you, on containers. This is sometimes annoying – for example when you want to add static routes with a post-up.

If you simply touch /etc/network/.pve-ignore.interfaces inside the container then it will let you manage it yourself and will thus obey any post-up lines that you add.