Nagios plugin to check memcached written in ruby

check_memcache.rb

#!/usr/bin/env ruby
# check_memcached.rb [email protected] 20091101 v0.1
# Copyright 2009, Dennis Kong 
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require "rubygems"
require "memcache"

ver = 0.1

if ARGV[3].nil?
	puts "#{$0} v#{ver} by Dennis Kong <[email protected]>"
	puts "Nagios plugin to check memcache and return status\r\n\r\n"
	puts "Usage: #{$0} <server> <port> <warning> <critical>"
	puts "e.g. #{$0} ./ localhost 11211 70 85"
	exit 3
end

warn 	= ARGV[2].to_i
crit 	= ARGV[3].to_i

unless (warn < crit)
	puts "<warning> must be less than <critical>"
	exit 3
end

server = "#{ARGV[0]}:#{ARGV[1]}"

stats = MemCache.new(server).stats[server]

limit_maxbytes  = stats["limit_maxbytes"].to_i 
bytes           = stats["bytes"].to_f

used = ((bytes / limit_maxbytes) * 100)

if (used > crit) 
  retval = 2
 elsif (used > warn)
  retval=  1
 else 
  retval = 0
end   

return_str = "bytes: #{bytes.to_i/1024000} MB limit_maxbytes: #{limit_maxbytes.to_i/1024000} MB"

stat_string = "usage: #{used.round}% #{return_str}" 

if ( retval == 0 )
	puts "OK - #{stat_string} \n"
	exit retval
 elsif ( retval == 1 ) 
	print "WARNING - #{stat_string} \n"
	exit retval
 elsif ( retval == 2 ) 
	print "CRITICAL - #{stat_string} \n"
	exit retval
end

exit retval