My default minimal Vagrantfile. Better than the huge thing 'vagrant init' generates.

Vagrantfile

Vagrant.configure("2") do |config|
  config.vm.box = "quantal64"
  config.vm.hostname = "give-this-a-name"
  config.vm.box_url = "http://cloud-images.ubuntu.com/quantal/current/quantal-server-cloudimg-vagrant-amd64-disk1.box"

  config.vm.provision :shell, :inline =>
    "sudo mkdir -p /root/.ssh && sudo cp /home/vagrant/.ssh/authorized_keys /root/.ssh/"

  # config.vm.network :forwarded_port, guest: 80, host: 8080
  # config.vm.synced_folder "../data", "/vagrant_data"
end