babushka_provisioner.rb

class BabushkaProvisioner < Vagrant::Provisioners::Base
  class Config < Vagrant::Config::Base
    attr_accessor :args
    attr_accessor :deps

    def initialize
      @deps = []
    end

    def dep(dep_spec, args = {})
      deps << [dep_spec, args]
    end
  end

  def self.config_class
    BabushkaProvisioner::Config
  end

  def provision!
    bootstrap_babushka! unless remote_host.test('babushka --version')

    config.deps.each do |(dep_name, dep_args)|
      remote_command(
        'babushka',
        '--update --defaults --colour', [config.args].flatten(1).join(' '),
        "'#{dep_name}'",
        *arg_pairs(dep_args)
      )

      # Disconnect after running each dep, so a new session is started
      # each time, for things like setting the locale.
      disconnect!
    end
  end

  private

  def bootstrap_babushka!
    require 'net/http'
    env[:ui].info("Installing babushka on #{host_name}.")
    tmpfile = File.expand_path("/tmp/babushka_me_up")
    File.open(tmpfile, 'w') {|f| f.write `curl https://babushka.me/up` }
    remote_host.upload(tmpfile, "/tmp/babushka_me_up")
    remote_command('bash /tmp/babushka_me_up')
  end

  def remote_command *cmd
    logged_cmd = cmd.map {|i| i.sub(/^(.{50})(.{3}).*/m, '\1...').sub(/\n/, ' ') }.join(' ') # the command, with long args truncated
    env[:ui].info "#{host_name}$ #{logged_cmd}"
    remote_host.sudo(cmd.join(' ')) do |type, data|
      if [:stderr, :stdout].include?(type)
        env[:ui].info(data.chomp, :prefix => false)
      end
    end
  end

  def arg_pairs arg_hash
    arg_hash.keys.map {|k| "#{k}='#{arg_hash[k]}'" }
  end

  def disconnect!
    remote_host.instance_variable_get('@connection').close
  end

  def remote_host
    env[:vm].channel
  end

  def host_name
    env[:vm].config.vm.host_name
  end
end

Vagrantfile

require './plugins/babushka_provisioner'

Vagrant::Config.run do |config|

  config.vm.box = "precise64"
  config.vm.box_url = 'http://files.vagrantup.com/precise64.box'

  config.vm.provision BabushkaProvisioner do |babs|
    babs.dep 'benhoskings:ruby.src', :version => '1.9.3', :patchlevel => 'p327'
  end

end