Workaround for Vagrant #2733

Vagrantfile

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

# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
VAGRANTFILE_API_VERSION = "2"

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  config.vm.box = "dummy"

  config.vm.provider :rackspace do |rs|
    rs.username = ENV['RAX_USERNAME']
    rs.api_key  = ENV['RAX_API_KEY']
    rs.rackspace_region   = :ord
  end

  supported_providers = %w(virtualbox rackspace)
  active_provider = ENV['VAGRANT_ACTIVE_PROVIDER'] # it'd be better to get this from the CLI --provider option
  supported_providers.each do |provider|
    next unless active_provider.nil? || active_provider == provider

    config.vm.define "exact_name_#{provider}" do |box|
      box.vm.provider :rackspace do |rs|
        rs.flavor = '1 GB Performance'
        rs.image  = 'Ubuntu 14.04 LTS (Trusty Tahr) (PVHVM)'
      end
    end

    config.vm.define "regex_#{provider}" do |box|
      box.vm.provider :rackspace do |rs|
        rs.flavor = /1\s+GB\s+Performance/
        rs.image  = /Ubuntu.*Trusty Tahr.*(PVHVM)/
      end
    end

    config.vm.define "id_#{provider}" do |box|
      box.vm.provider :rackspace do |rs|
        rs.flavor = 'performance1-1'
        rs.image  = 'bb02b1a3-bc77-4d17-ab5b-421d89850fca'
      end
    end

    config.vm.define "unlisted_#{provider}" do |box|
      box.vm.provider :rackspace do |rs|
        rs.flavor = 'performance1-1'
        rs.image = '547a46bd-d913-4bf7-ac35-2f24f25f1b7a'
      end
    end
  end
end

It'd be better to get this from the CLI --provider option.

require 'getoptlong'
opts = GetoptLong.new(
  [ '--provider', GetoptLong::OPTIONAL_ARGUMENT ]
)

provider=ENV['PROVIDER'] || 'virtualbox'
opts.each do |opt, arg|
  case opt
    when '--provider'
      provider=arg
  end
end

Vagrant.configure(2) do |config|
  config.vm.define "default-#{provider}"
  # ...
end