template.json

{
    "builders": [{
        "type": "virtualbox-iso",
        "iso_url": "boot2docker.iso",
        "iso_checksum": "681c3aae0c54bb003fe1175f62697662",
        "iso_checksum_type": "none",
        "boot_wait": "5s",
        "ssh_username": "docker",
        "ssh_password": "tcuser",
        "shutdown_command": "sudo poweroff",
        "guest_additions_mode": "disable",
        "guest_os_type": "Linux_64",
        "vboxmanage": [
            ["storageattach", "{{.Name}}", "--storagectl", "IDE Controller",
                "--port", "0", "--device", "0",
                "--type", "hdd", "--medium", "persistent2.vmdk"]
        ]
    }],

    "provisioners": [{
        "type": "file",
        "source": "files/",
        "destination": "/tmp"
    }, {
        "type": "shell",
        "inline": [
            "sudo cp /tmp/sshd_config /var/lib/docker/vm/ssh/sshd_config",
            "sudo cp /tmp/vagrant_key.pub /var/lib/docker/vm/ssh/docker_authorized_keys",
            "sudo chown docker:docker /var/lib/docker/vm/ssh/docker_authorized_keys",
            "sudo chmod 0600 /var/lib/docker/vm/ssh/docker_authorized_keys"
        ]
    }],

    "post-processors": [{
        "type": "vagrant",
        "include": ["boot2docker.iso"],
        "vagrantfile_template": "vagrantfile_virtualbox.tpl",
        "output": "boot2docker.box"
    }]
}