Vagrantfile.rb

# -*- mode: ruby -*-
# vi: set ft=ruby :

# this works with `ruby Vagrantfile`
#   but not `vagrant up`

require 'yaml'
require 'erubis'

@cfg = YAML::load(DATA)
@boxes = @cfg.keys.map(&:to_sym)

puts @cfg.to_s

Vagrant.configure("2") do |config|
  raise @cfg.inspect  
end

__END__
---
chef:
  box: opscode_ubuntu-12.04_provisionerless.box
  host_name: chef.local
  boot_mode: headless
  net:
    mode: 
    ip: 
    mask: 
  port: 
    ssh: 2200
    http: 8800
  ssh:
    username: 
    shell: 
  share:
    type: nfs
    hostpath: 
    guestpath: 
  omnibus:
    chef_version: latest
  chef:     
    cookbooks_path: 
    recipes:
      - build_essential