fog--fog/lib/fog/core/credentials.rb

require 'yaml'
module Fog
  class << self

    def credential=(new_credential)
      @credential = new_credential
      @credentials = nil
    end

    def credential
      @credential || :default
    end

    def config_path
      ENV["FOG_RC"] || '~/.fog'
    end

    def credentials
      @credentials ||= begin
        path = File.expand_path(config_path)
        credentials = if File.exists?(path)
          File.open(path) do |file|
            YAML.load(file.read)
          end
        else
          nil
        end
        unless credentials && credentials[credential]
          print("\n  To run as '#{credential}', add the following to #{config_path}\n")
          yml = <<-YML
:#{credential}:
  :aws_access_key_id:                INTENTIONALLY_LEFT_BLANK
  :aws_secret_access_key:            INTENTIONALLY_LEFT_BLANK
  :bluebox_api_key:                  INTENTIONALLY_LEFT_BLANK
  :bluebox_customer_id:              INTENTIONALLY_LEFT_BLANK
  :brightbox_client_id:              INTENTIONALLY_LEFT_BLANK
  :brightbox_secret:                 INTENTIONALLY_LEFT_BLANK
  :go_grid_api_key:                  INTENTIONALLY_LEFT_BLANK
  :go_grid_shared_secret:            INTENTIONALLY_LEFT_BLANK
  :google_storage_access_key_id:     INTENTIONALLY_LEFT_BLANK
  :google_storage_secret_access_key: INTENTIONALLY_LEFT_BLANK
  :local_root:                       INTENTIONALLY_LEFT_BLANK
  :new_servers_password:             INTENTIONALLY_LEFT_BLANK
  :new_servers_username:             INTENTIONALLY_LEFT_BLANK
  :public_key_path:                  INTENTIONALLY_LEFT_BLANK
  :private_key_path:                 INTENTIONALLY_LEFT_BLANK
  :rackspace_api_key:                INTENTIONALLY_LEFT_BLANK
  :rackspace_username:               INTENTIONALLY_LEFT_BLANK
  :slicehost_password:               INTENTIONALLY_LEFT_BLANK
  :terremark_username:               INTENTIONALLY_LEFT_BLANK
  :terremark_password:               INTENTIONALLY_LEFT_BLANK
YML
          print("\n#{yml}\n")
          raise(ArgumentError.new("Missing Credentials"))
        end
        credentials[credential]
      end
    end

  end
end