#!/usr/bin/env ruby

# Gathers redis INFO statistics and submits them to Riemann.

require File.expand_path('../../lib/riemann/tools', __FILE__)

class Riemann::Tools::Redis
  include Riemann::Tools
  require 'redis'

  opt :redis_host, "Redis hostname", :default => 'localhost'
  opt :redis_port, "Redis port", :default => 6379
  opt :redis_password, "Redis password", :default => ''
  opt :redis_url, "Redis URL", :default => ''
  opt :redis_socket, "Redis socket", :default => ''
  opt :redis_section, "Redis INFO section", :default => 'default'

  STRING_VALUES = %w{ redis_version redis_git_sha1 redis_mode os
                      multiplexing_api gcc_version run_id used_memory_human
                      used_memory_peak_human mem_allocator
                      rdb_last_bgsave_status aof_last_bgrewrite_status role }

  def initialize
    options = if opts[:redis_url] != ''
                { :url => opts[:redis_url] }
              elsif opts[:redis_socket] != ''
                { :path => opts[:redis_socket] }
              else
                { :host => opts[:redis_host], :port => opts[:redis_port] }
              end
    @redis = ::Redis.new(options)
    @redis.auth(opts[:redis_password]) unless opts[:redis_password] == ''
    @section = opts[:redis_section]
  end

  def tick
    begin
      @redis.info(@section).each do |property, value|
        data = {
          :host    => opts[:redis_host].dup,
          :service => "redis #{property}",
          :metric  => value.to_f,
          :state   => value.to_s,
          :tags    => ['redis']
        }

        if STRING_VALUES.include?(property) || property.match(/^db\d+/)
          if %w{ rdb_last_bgsave_status aof_last_bgrewrite_status }.include?(property)
            data[:state] = value
          else
            data[:description] = value
          end
        end

        if property == "run_id"
          data[:metric] = 0
        end

        report(data)
      end
    rescue ::Redis::CommandError => e
      if e.message == "ERR operation not permitted"
        @redis.auth(opts[:redis_password]) unless opts[:redis_password] == ''
      end
    end

  end

end

Riemann::Tools::Redis.run