preseed.cfg

### Localization
d-i locale string en_US
d-i keymap select US

### Network
d-i interface select auto
d-i hostname string unassigned-hostname
d-i domain string unassigned-domain

### Accounts
d-i passwd/root-login boolean false
d-i passwd/root-password password vagrant
d-i passwd/root-password-again password vagrant
d-i passwd/username string vagrant
d-i passwd/user-fullname string vagrant
d-i passwd/user-password password vagrant
d-i passwd/user-password-again password vagrant

### Clock/Timezone
d-i clock-setup/utc boolean true
d-i time/zone string UTC
d-i clock-setup/ntp boolean true

### Partition
d-i partman-auto/method string lvm
d-i partman-lvm/confirm boolean true
d-i partman-lvm/confirm_nooverwrite boolean true
d-i partman-auto/choose_recipe select atomic
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true


### Mirror settings
d-i mirror/http/proxy string

### Packages
popularity-contest popularity-contest/participate boolean false
d-i pkgsel/install-language-support boolean false
d-i pkgsel/include string build-essential ssh sudo curl wget locate nfs-common
d-i pkgsel/update-policy select unattended-upgrades
d-i pkgsel/upgrade select safe-upgrade

### Grub
d-i grub-installer/only_debian boolean true

### Finish
d-i cdrom-detect/eject boolean false
d-i finish-install/reboot_in_progress note

template.json

{
  "builders": [
    {
      "type": "virtualbox-iso",
      "iso_checksum": "9792020579824057723446a92ab97d50fdb7af15d265ff4be9081a963e36b3e3e6f44127766219320bc863c6a7ec378388a9d6faa7b51c3f74b259dc9049e071",
      "iso_checksum_type": "sha512",
      "iso_url": "http://cdimage.debian.org/cdimage/archive/7.8.0/amd64/iso-cd/debian-7.8.0-amd64-netinst.iso",
      "ssh_username": "vagrant",
      "ssh_password": "vagrant",
      "boot_command": [
        "<esc><wait>",
        "auto url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg <wait>",
        "<enter><wait>"
      ],
      "boot_wait": "5s",
      "disk_size": 20480,
      "guest_additions_mode": "disable",
      "guest_os_type": "Debian_64",
      "hard_drive_interface": "sata",
      "headless": false,
      "http_directory": "http",
      "iso_interface": "sata",
      "shutdown_command": "echo vagrant | sudo -S /sbin/shutdown -hP now",
      "vboxmanage": [
        ["modifyvm", "{{ .Name }}", "--memory", 512],
        ["modifyvm", "{{ .Name }}", "--cpus", 2],
        ["modifyvm", "{{ .Name }}", "--vram", 8]
      ]
    }
  ],
  "description": "Debian 7.8 (Wheezy) x64"
}