auto-mount external storage

[haaber]

I would like a specific appVM (say "private") to auto-mount an encrypted
container. So, the wanted behaviour is: I plug in a usb / hard drive,
attach it to my appVM (private) and then see it opened and mounted in
(say) /home/user/data without any further action, typing passwords etc.
On std linux this would be done using a LUKS keyfile, and by editing
/etc/crypttab and /etc/fstab/

Question: Where do I have to locate these files in qubes-os to have them
survive a reboot? Do I need an extra template "just for that" ? Cheers!