template.json

{
    "variables": {
        "swap_size": "",
        "disk_size": "20000",
        "memmory_size": "4096",
        "cpus": "4",
        "vm_name": "nixos-16.09-x86_64",
        "iso_url": "https://d3g5gsiof5omrk.cloudfront.net/nixos/16.09/nixos-16.09.1694.019dcc3/nixos-minimal-16.09.1694.019dcc3-x86_64-linux.iso",
        "iso_checksum_type": "sha256",
        "iso_checksum": "e44768129e7648dd590f6029162a34ba6897db9737043c7fabe7443b21de06fc"
    },
    "builders": [{
        "type": "virtualbox-iso",
        "boot_wait": "1m",
        "boot_command": [
            "root<enter>",
            "stop sshd<enter>",
            "fdisk /dev/sda<enter>",
            "n",
            "<enter><enter><enter><enter><enter>",
            "a<enter>",
            "1<enter>",
            "w<enter>",
            "<wait>",
            "mkfs.ext4 -j -L nixos /dev/sda1<enter><wait5>",
            "mount LABEL=nixos /mnt<enter><wait>",
            "nixos-generate-config --root /mnt<enter><wait>",
            "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/configuration.nix > /mnt/etc/nixos/configuration.nix<enter><wait>",
            "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/guest-virtualbox.nix > /mnt/etc/nixos/guest.nix<enter><wait>",
            "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/users-vagrant.nix > /mnt/etc/nixos/users.nix<enter><wait>",
            "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/vagrant.nix > /mnt/etc/nixos/vagrant.nix<enter><wait>",
            "curl http://{{ .HTTPIP }}:{{ .HTTPPort }}/emacs.nix > /mnt/etc/nixos/emacs.nix<enter><wait>",
            "nixos-install && reboot<enter>"
        ],
        "guest_additions_mode": "disable",
        "guest_os_type": "Linux_64",
        "http_directory": "nixos",
        "iso_checksum": "{{ user `iso_checksum` }}",
        "iso_checksum_type": "{{ user `iso_checksum_type` }}",
        "iso_url": "{{ user `iso_url` }}",
        "shutdown_command": "sudo shutdown -h now",
        "ssh_username": "root",
        "ssh_private_key_file": "keys/vagrant.key",
        "ssh_wait_timeout": "20m",
        "virtualbox_version_file": ".vbox_version",
        "vboxmanage": [
            ["modifyvm", "{{.Name}}", "--memory", "{{ user `memmory_size` }}"],
            ["modifyvm", "{{.Name}}", "--cpus", "{{ user `cpus` }}"]
        ]
    }],
    "provisioners": [{
            "type": "shell",
            "execute_command": "sudo sh '{{.Path}}'",
            "script": "scripts/postinstall.sh"
        },
        {
            "type": "file",
            "source": "provision/.emacs",
            "destination": "/home/vagrant/.emacs"
        }
    ],
    "post-processors": [{
        "type": "vagrant",
        "output": "{{ user `vm_name` }}-{{.Provider}}.box"
    }]
}