Read in the knife.rb configuration to pass into the Vagrant chef-client provisioner

Vagrantfile.rb

require 'chef'
require 'chef/config'
require 'chef/knife'

current_dir = File.dirname(__FILE__)
Chef::Config.from_file(File.join(current_dir, '.chef', 'knife.rb'))

Vagrant::Config.run do |config|
  config.vm.provision :chef_client do |chef|
    chef.chef_server_url = Chef::Config[:chef_server_url]
    chef.validation_key_path = "#{current_dir}/.chef/#{Chef::Config[:validation_client_name]}.pem"
    chef.validation_client_name = Chef::Config[:validation_client_name]
  end
end