custom logger wrapping slogger gem

caller.rb

CustomLogger.info 'here is info'
CustomLogger.debug'here is debug'
CustomLogger.warn 'here is warn'
CustomLogger.error 'here is error'
# and this will record the execution time of the block and inject it into the message
CustomLogger.info 'here is a timing item.  i wonder how long it will take' do
    sleep 10
end

custom_logger.rb

class CustomLogger
  LOG_LEVELS = ['debug', 'info', 'warn', 'error']

  def self.log(level, *args, &block)
    setup_logger unless @logger
    @logger.send level.to_sym, *args, &block
  end

  class << self
    LOG_LEVELS.each do |level|
      define_method level do |*args, &block|
        self.log level, *args, &block
      end
    end
  end

  private
  def self.setup_logger
    @logger = Slogger::CommonLogger.new determine_app_name,
                                        determine_level,
                                        determine_facility
  end

  def self.determine_app_name
    default_app_name = 'custom_logger'

    app_name = ENV['LOGGER_APP_NAME'] || default_app_name

    if app_name == default_app_name && (Object.const_defined? :Rails)
      app_name = Rails.application.config.app_name
    end

    app_name
  end

  def self.determine_level
    ENV['LOGGER_LEVEL'] || :info
  end

  def self.determine_facility
    ENV['LOGGER_FACILITY'] || :local2
  end

end