Custom Log Formatting - Rails 3

application.rb

    logger = Logger.new(File.join( Rails.root, "log", "my_#{ Rails.env}.log"), 'daily')
    logger.level = Logger::INFO
    logger.formatter = proc do |severity, datetime, progname, msg|
      "#{datetime.strftime("%B %d %H:%M:%S")} #{Socket.gethostname}, [#{$$}]:, #{severity}  MY_WEBAPP, #{msg}\n"
    end

    tag_log = ActiveSupport::TaggedLogging.new(logger)
    config.logger = tag_log

   # above code will produce log in format as shown below,

   <Month> <Day> <HH:MM:SS> <HostName>, [pid]:, <Level>, <Category>, <Msg>