Redis info output plugin

redis_info.rb

module Fluent
  class RedisInfo < Input
    Plugin.register_input('redisinfo', self)

    config_param :uri, :string
    config_param :stats_interval, :time, :default => 60 # every minute
    config_param :tag_prefix, :string, :default => "redisinfo"

    def initialize
      super
      require 'redis'
    end

    def configure(conf)
      super

      unless @uri
        raise ConfigError, 'uri must be specified'
      end

      @conn = Redis.new(:url => @uri)
    end

    def start
      @loop = Coolio::Loop.new
      tw = TimerWatcher.new(@stats_interval, true, @log, &method(:collect_info))
      tw.attach(@loop)
      @thread = Thread.new(&method(:run))
    end

    def run
      @loop.run
    rescue
      log.error "unexpected error", :error=>$!.to_s
      log.error_backtrace
    end

    def shutdown
      @loop.stop
      @thread.join
    end

    def collect_info
      begin

        stats = @conn.client.call([:info])
        if stats.kind_of?(String)
          stats = Hash[stats.split("\r\n").map do |line|
            line.split(":", 2) unless line =~ /^(#|$)/
          end]
        end

        Engine.emit(@tag_prefix, Engine.now, stats)

      rescue => e
        log.error "failed to collect Redis info", :error_class => e.class, :error => e
      end
    end

    class TimerWatcher < Coolio::TimerWatcher

      def initialize(interval, repeat, log, &callback)
        @callback = callback
        @log = log
        super(interval, repeat)
      end
      def on_timer
        @callback.call
      rescue
        @log.error $!.to_s
        @log.error_backtrace
      end
    end
  end
end