{
  "variables": {
    "iso_url": "http://dl-cdn.alpinelinux.org/alpine/v3.9/releases/x86_64/alpine-standard-3.9.3-x86_64.iso",
    "iso_checksum": "6e28c5c902ccb6db24596dfb6a1c255c7989d0b9be4e92e87a8eff523201a459",
    "iso_checksum_type": "sha256",

    "boot_wait": "10s",

    "root_password": null,
    "ssh_timeout": "60m",

    "machine_hostname": "unifi",

    "http_directory": "http/",
    "output_directory": "output/base/"
  },
  "builders": [
    {
      "type": "virtualbox-iso",
      "guest_os_type": "Linux_64",
      "format": "ova",

      "iso_url": "{{user `iso_url`}}",
      "iso_checksum": "{{user `iso_checksum`}}",
      "iso_checksum_type": "{{user `iso_checksum_type`}}",

      "http_directory": "{{user `http_directory`}}",
      "output_directory": "{{user `output_directory`}}",

      "boot_wait": "{{user `boot_wait`}}",
      "boot_command": [
        "root<enter><wait>",

        "ifconfig eth0 up && ",
        "udhcpc -i eth0<enter>",
        "<wait5>",

        "wget http://{{ .HTTPIP }}:{{ .HTTPPort }}/answers<enter><wait>",
        "sed -i ",
        "-e \"s/:hostname:/{{user `machine_hostname`}}/g\" ",
        "answers<enter>",

        "sed -i \"s/rc-service \\$svc start/#&/\" /sbin/setup-sshd<enter>",

        "setup-alpine -f answers && ",
        "mount /dev/sda3 /mnt && ",
        "echo 'PermitRootLogin yes' >> /mnt/etc/ssh/sshd_config && ",
        "rc-update add acpid && ",
        "umount /mnt && ",
        "reboot",
        "<enter>",
        "<wait5>",

        "{{user `root_password`}}<enter><wait>",
        "{{user `root_password`}}<enter><wait20>",

        "y<enter>"
      ],

      "communicator": "ssh",
      "ssh_username": "root",
      "ssh_password": "{{user `root_password`}}",
      "ssh_timeout": "{{user `ssh_timeout`}}"
    }
  ]
}