Ansible playbook that implements https://github.com/zfsonlinux/zfs/wiki/Ubuntu-18.04-Root-on-ZFS

• Edit ansible/vars.yml with your desired settings.
• Run packer build -on-error=ask ubuntu-zfs-{{ mbr || efi }}.json to test the playbook in a Virtualbox machine.
• The last provisioner is simply a shell provisioner that runs false, so you can examine the resulting system once the playbook has completed.
• Playbook hasn't yet been tested on real hardware, will report back with more commits
  • it should go without saying, but trying to run this on real hardware will result in data loss

• zfsprep_zap_disks: true - forcibly nuke any partitions on existing disks
• zfsprep_legacy_device_nodes - set to true to use /dev/sdX device names instead of by-id
• zfsprep_root_pool - root pool name
• zfsprep_data_pool - data pool name (separate from root pool)
• zfsprep_efi: true - Use EFI layout, install grub-efi instead of grub-pc. Set to false to install grub-pc instead
• zfsprep_luks - LUKS support
• zfsprep_luks_flags - flags to pass to luksFormat
• zfsprep_luks_passphrase - passphrase for luksFormat/luksOpen
• zfsprep_hostname - short and FQDN hostnames to configure in the target OS
• zfsprep_root_disks - target disks for root pool
• zfsprep_data_disks - target disks for data pool
• zfsprep_root_pool_type - pool type for root pool
• zfsprep_data_pool_type - pool type for data pool
• zfsprep_extra_locales - list of extra locales to install alongside en_US.UTF-8
• zfsprep_lang - LANG to set in /etc/default/locale
• zfsprep_timezone - timezone to set in resulting OS (defaults to UTC)

a few more in ansible/roles/01-system-prep/defaults/main.yml