configuration_utils.rb

# Encoding: utf-8
# Cloud Foundry Java Buildpack
# Copyright 2013-2015 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require 'pathname'
require 'java_buildpack/util'
require 'java_buildpack/logging/logger_factory'
require 'yaml'

module JavaBuildpack
  module Util

    # Utilities for dealing with Groovy applications
    class ConfigurationUtils

      private_class_method :new

      class << self

        # Loads a configuration file from the buildpack configuration directory.  If the configuration file does not
        # exist, returns an empty hash.
        #
        # @param [String] identifier the identifier of the configuration
        # @param [Boolean] should_log whether the contents of the configuration file should be logged.  This value
        #                             should be left to its default and exists to allow the logger to use the utility.
        # @return [Hash] the configuration or an empty hash if the configuration file does not exist
        def load(identifier, should_log = true)
          file = CONFIG_DIRECTORY + "#{identifier}.yml"

          if file.exist?
            configuration = YAML.load_file(file)
            logger.debug { "Configuration from #{file}: #{configuration}" } if should_log
          else
            logger.debug { "No configuration file #{file} found" } if should_log
          end

          configuration || {}
        end

        private

        CONFIG_DIRECTORY = Pathname.new(File.expand_path('../../../config', File.dirname(__FILE__))).freeze

        private_constant :CONFIG_DIRECTORY

        def logger
          JavaBuildpack::Logging::LoggerFactory.instance.get_logger ConfigurationUtils
        end

      end

    end

  end
end