check-redis-list-length.rb

#!/usr/bin/env ruby
#
# Checks number of items in a Redis list key
# ===
#
# Depends on redis gem
# gem install redis
#
# Copyright (c) 2013, Piavlo <lolitushka@gmail.com>
#
# Released under the same terms as Sensu (the MIT license); see LICENSE
# for details.

require 'rubygems' if RUBY_VERSION < '1.9.0'
require 'sensu-plugin/check/cli'
require 'redis'

class RedisListLengthCheck < Sensu::Plugin::Check::CLI

  option :host,
    :short => "-h HOST",
    :long => "--host HOST",
    :description => "Redis Host to connect to",
    :required => false,
    :default => '127.0.0.1'

  option :port,
    :short => "-p PORT",
    :long => "--port PORT",
    :description => "Redis Port to connect to",
    :proc => proc {|p| p.to_i },
    :required => false,
    :default => 6379

  option :database,
    :short => "-n DATABASE",
    :long => "--dbnumber DATABASE",
    :description => "Redis database number to connect to",
    :proc => proc {|p| p.to_i },
    :required => false,
    :default => 0

  option :password,
    :short => "-P PASSWORD",
    :long => "--password PASSWORD",
    :description => "Redis Password to connect with"

  option :warn,
    :short => "-w COUNT",
    :long => "--warning COUNT",
    :description => "COUNT warning threshold for number of items in Redis list key",
    :proc => proc {|p| p.to_i },
    :required => true

  option :crit,
    :short => "-c COUNT",
    :long => "--critical COUNT",
    :description => "COUNT critical threshold for number of items in Redis list key",
    :proc => proc {|p| p.to_i },
    :required => true

  option :key,
    :short => "-k KEY",
    :long => "--key KEY",
    :description => "Redis list KEY to check",
    :required => true

  def run
    begin
      options = {:host => config[:host], :port => config[:port], :db => config[:database]}
      options[:password] = config[:password] if config[:password]
      redis = Redis.new(options)

      length = redis.llen(config[:key])

      if (length >= config[:crit])
        critical "Redis list #{config[:key]} length is above the CRITICAL limit: #{length} length / #{config[:crit]} limit"
      elsif (length >= config[:warn])
        warning "Redis list #{config[:key]} length is above the WARNING limit: #{length} length / #{config[:warn]} limit"
      else
        ok "Redis list #{config[:key]} length is below thresholds"
      end
    rescue
      unknown "Could not connect to Redis server on #{config[:host]}:#{config[:port]}"
    end
  end

end