Install talos nocloud and add CIDATA with config

talos_nocloud_cidata.bash

#!/usr/bin/env bash
# This assumes a booted rescue system, copies the installation media to the destination disk
# it'll then add a CIDATA partition to the end of the disk, and prepare it with user-data
# used in a terraform ssh provisioner, but extracted to here for now.

destination_disk=/dev/nvme0n1
talos_version=v0.14.3

wipefs -af $destination_disk
wget https://github.com/talos-systems/talos/releases/download/${talos_version}/nocloud-amd64.raw.xz
xzcat nocloud-amd64_.raw.xz | dd of=${destination_disk} bs=1M
sgdisk --move-second-header ${destination_disk}
# create new CIDATA partition at the end of the disk
sgdisk --new 0:-100M:0 --typecode 0:8300 ${destination_disk} --change-name=0:'CIDATA' ${destination_disk}

apt install -y genisoimage
# write config as user-data
echo CONFIG_GOES_HERE > user-data

# assemble a ISO
genisoimage -output cidata.iso -V cidata -r -J user-data

# write to partition
dd if=cidata.iso of=/dev/disk/by-partlabel/CIDATA bs=1M