[kangsterizer]

I've a more or less similar script that uses overlayfs. More less than more... since it uses machined really. But it's easy to to grab commands from there and put in bocker for ex. You just need to replace the btrfs commands by the overlayfs mount, it's almost nothing :)

https://github.com/gdestuynder/mctl/ See also this terrible draft https://www.insecure.ws/linux/systemd_nspawn.html