Logging to multiple destinations in Ruby

multi_logger.rb

class MultiLogger
  attr_reader :level

  def initialize(args={})
    @level = args[:level] || Logger::Severity::DEBUG
    @loggers = []

    Array(args[:loggers]).each { |logger| add_logger(logger) }
  end

  def add_logger(logger)
    logger.level = level
    @loggers << logger
  end

  def level=(level)
    @level = level
    @loggers.each { |logger| logger.level = level }
  end

  def close
    @loggers.map(&:close)
  end

  def add(level, *args)
    @loggers.each { |logger| logger.add(level, args) }
  end

  Logger::Severity.constants.each do |level|
    define_method(level.downcase) do |*args|                
      @loggers.each { |logger| logger.send(level.downcase, args) }
    end

    define_method("#{ level.downcase }?".to_sym) do
      @level <= Logger::Severity.const_get(level)
    end
  end
end

usage.rb

log_1 = Logger.new(STDOUT)
log_2 = Logger.new(File.open('/tmp/foo'))

multi_logger = MultiLogger.new(:level => Logger::WARN, :loggers => log_1)
multi_logger.add_logger(log_2)

multi_logger.warn('Something interesting happened.')