data_bag_common.rb

require "chef/config"
require "chef/knife"
require "chef/log"
require "chef/mixin/convert_to_class_name"

module DataBagCommon

  def self.included(base)
    base.module_eval do
      def read_secret
        if locate_config_value(:secret)
          locate_config_value(:secret)
        else
          Chef::EncryptedDataBagItem.load_secret(locate_config_value(:secret_file))
        end
      end

      def use_encryption
        if locate_config_value(:secret) && locate_config_value(:secret_file)
          stdout.puts "please specify only one of --secret, --secret-file"
          exit(1)
        end
        locate_config_value(:secret) || locate_config_value(:secret_file)
      end
    end
  end

  def locate_config_value(key)
    key = key.to_sym
    Chef::Config[:knife][key] || config[key]
  end

end

%w[data_bag_create data_bag_show data_bag_edit data_bag_from_file].each do |k|
  class_name = Chef::Mixin::ConvertToClassName.convert_to_class_name(k)
  super_class = Chef::Knife.const_get(class_name)

  eval <<-EOH
class #{super_class}
  include DataBagCommon
end
EOH

end