Ask interactively values in Vagrant

Vagrantfile

# This is sample script that let user input some values interactively
# also it caches theses values in .vagrant/app_data.json so after restart
# user will not need to enter again same values
#
# To use this class you need to use DataLoader.instance.ask everywhere where you needed to have dynamic data.
#
# Syntax: DataLoader.instance.ask(VARIABLE_NAME_TO_SAVE, PROMPT_MESSAGE, DATA_TYPE)
#         VARIABLE_NAME_TO_SAVE - dictionary key name where to save value
#         PROMPT_MESSAGE - prompt message that will be displayed before input
#         DATA_TYPE - :password or :text
#
# Use this to save data:
# config.trigger.after :provision do |trigger|
#   trigger.info = "Data saved" if DataLoader.instance.save
# end

# Add this class to beginning of your Vagrantfile:
class DataLoader
  include Singleton

  @@data = {}
  @@changed = false

  def initialize
    load
  end

  def ask(name, message, type)
    return @@data[name] if @@data.key?(name)
    require 'io/console'
    case type
      when :password
        @@data[name] = STDIN.getpass(message).chomp
      else
        print message
        @@data[name] = STDIN.gets.chomp
    end
    @@changed = true
  end

  def save
    return false unless @@changed
    File.open(filename, 'w') do |file|
      file.write to_json
    end
    @@changed = false
    true
  end

  :protected

  def enc_data_org
    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
  end

  def enc_data_rnd
    "1aj6tRx7b39ASKeq5sYVOEFMoZX2N4DwyzndGJChLg0kfQPrilUTBIWpc8vHum"
  end

  def to_json
    require 'json'

    JSON.generate(@@data).tr enc_data_org, enc_data_rnd
  end

  def filename
    File.join '.vagrant', 'app_data.json'
  end

  def load
    if File.exist?(filename)
      require 'json'

      puts "Reading saved app data..."
      contents = File.read(filename)
      decoded = contents.tr(enc_data_rnd, enc_data_org)
      @@data = JSON.parse(decoded)
    end
  end
end

# Here is sample usage ('autologin to gitlab docker container registry'):
Vagrant.configure("2") do |config|
  config.vm.box = "resmas/dockerlab"
  
  config.vm.provision :docker
  config.vm.provision :docker_compose,
                      compose_version: '1.22.0'
  config.vm.provision :docker_login,
                      server: 'registry.gitlab.com',
                      username: DataLoader.instance.ask('gitlab_user', 'GitLab login: ', :text),
                      password: DataLoader.instance.ask('gitlab_password', 'GitLab password: ', :password)
  
  config.trigger.after :provision do |trigger|
    trigger.info = "Data saved" if DataLoader.instance.save
  end
end