template.json

{
  "builders": [
    {
      "boot_wait": "4s",
       "cpus": "{{ user `cpus` }}",
       "disk_size": "{{user `disk_size`}}",
       "guest_additions_path": "VBoxGuestAdditions_{{.Version}}.iso",
       "guest_os_type": "Ubuntu_64",
       "hard_drive_interface": "sata",
       "headless": "{{ user `headless` }}",
       "http_directory": "{{user `http_directory`}}",
      "iso_checksum": "file:{{ user `iso_checksum_url` }}",
      "iso_url": "{{ user `iso_url` }}",
       "memory": "{{ user `memory` }}",
      "output_directory": "{{ user `build_directory` }}/{{ user `box_basename` }}-{{ user `iso_version` }}-VirtualBox",
       "shutdown_command": "echo 'vm4dev' | sudo -S shutdown -P now",
       "ssh_password": "pw",
       "ssh_port": 22,
       "ssh_timeout": "10000s",
       "ssh_username": "user",
       "type": "virtualbox-iso",
       "virtualbox_version_file": ".vbox_version",
       "vm_name": "{{ user `box_basename` }}-{{ user `iso_version` }}"
    }
],
  "variables": {
    "boot_command": "c<wait>set gfxpayload=keep<enter><wait>linux /casper/vmlinuz<wait> debug-ubiquity DEBCONF_DEBUG=5 automatic-ubiquity noprompt url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg<wait> ---<enter><wait>initrd /casper/initrd<enter><wait>boot<enter><wait>",
    "boot_wait": "4s",
    "box_basename": "Ubuntu-Desktop",
    "build_directory": "build",
    "compression_level": "9",
    "cpus": "2",
    "description": "Ubuntu Desktop 22.04",
    "disk_size_root": "20000",
    "disk_size_home": "20000",
    "headless": "false",
    "http_directory": "http",
    "iso_checksum_url": "https://releases.ubuntu.com/22.04/SHA256SUMS",
    "iso_url": "https://releases.ubuntu.com/22.04/ubuntu-22.04-desktop-amd64.iso",
    "iso_version": "22.04",
    "latestos_tag": "ubuntu",
    "memory": "4096",
    "shutdown_command": "echo '{{ user `ssh_password` }}' | sudo -S shutdown -P now",
    "ssh_password": "pw",
    "ssh_port": "22",
    "ssh_timeout": "230m",
    "ssh_username": "user"
  }
}