Comment 4 for bug 1983041

Got it working!

I switched mbr back to gpt (I presume mbr isn't a valid option) and I set the disk size to -1 which has used all the space available so we can get away with a generic cloud-init file for my LTSP image creator script.

I would recommend adding the path to autoinstall-user-data to the autoinstall-quickstart guide with a few good tips on configuring it like setting disk size to -1 to use all the space.

#cloud-config
autoinstall:
  apt:
    disable_components: []
    geoip: true
    preserve_sources_list: false
    primary:
    - arches:
      - amd64
      - i386
      uri: http://gb.archive.ubuntu.com/ubuntu
    - arches:
      - default
      uri: http://ports.ubuntu.com/ubuntu-ports
  drivers:
    install: false
  identity:
    hostname: ltspbase
    password: GOESHERE
    realname: ubuntu
    username: ubuntu
  kernel:
    package: linux-generic
  keyboard:
    layout: gb
    toggle: null
    variant: ''
  locale: en_GB.UTF-8
  network:
    ethernets:
      enp0s3:
        dhcp4: true
    version: 2
  ssh:
    allow-pw: true
    authorized-keys: []
    install-server: false
  storage:
    config:
    - ptable: gpt
      path: /dev/sda
      wipe: superblock-recursive
      preserve: false
      name: ''
      grub_device: true
      type: disk
      id: disk-sda
    - device: disk-sda
      size: 1048576
      flag: bios_grub
      number: 1
      preserve: false
      grub_device: false
      type: partition
      id: partition-0
    - device: disk-sda
      size: -1
      wipe: superblock
      flag: ''
      number: 2
      preserve: false
      grub_device: false
      type: partition
      id: partition-1
    - fstype: ext4
      volume: partition-1
      preserve: false
      type: format
      id: format-0
    - path: /
      device: format-0
      type: mount
      id: mount-0
  updates: security
  version: 1