ZFS auto load key and mount datasets

[runningman84]

Feature Request

It would be great if the zfs importer service would also call zfs load-key -a in order to load all keys from the disk (which could be stored for example in /var/keyname.key). Furthermore it should also autmount the datasets using zfs mount.

Description

Right now it is difficult to deal with zfs in talos because some commands can only be executed in some privileged pod. At this point it is already too late in the boot process and some other pods might crash because they cannot access the data.

Reference docs

https://arstechnica.com/gadgets/2021/06/a-quick-start-guide-to-openzfs-native-encryption/
https://wiki.archlinux.org/title/ZFS#Unlock_at_boot_time:_systemd

[runningman84]

This should do the trick siderolabs/extensions#400