A sample plugin to collect data from squid

squid_collectd.rb

#!/usr/bin/env ruby
require 'getoptlong'
require 'yaml'

#need to sync stdout with collectd execs!
$stdout.sync = true

if File.readable? '/etc/mcollective/facts.yaml'
  facts=YAML::load(File.open('/etc/mcollective/facts.yaml'))
else
  exit! 1
end

args = {  :interval => 30, 
          :hostname => facts['hostname'],
          :path => '/usr/local/squid/bin/squidclient',
          :port => 3128 }

opts = GetoptLong.new(
  [ '--interval', '-i', GetoptLong::OPTIONAL_ARGUMENT ],
  [ '--port', '-p', GetoptLong::OPTIONAL_ARGUMENT ],
  [ '--host', '-h', GetoptLong::OPTIONAL_ARGUMENT ],
  [ '--path', '-u', GetoptLong::OPTIONAL_ARGUMENT ],
)

opts.each do |opt, arg|
  case opt
    when '--interval'
      args[:interval] = arg.to_i
    when '--port'
      args[:port] = arg.to_i
    when '--host'
      args[:host] = arg
    when '--path'
      args[:path] = arg
  end
end


@@regexps = {
            :all_requests_service_median => { :exp => Regexp.compile(/HTTP Requests \(All\):   ([0-9\.]+)/), :type => 'gauge' },
            :all_cache_hit_rate => { :exp => Regexp.compile(/Hits as \% of all requests:\s+5min:\s+([0-9\.]+)/), :type => 'gauge' },
            :cache_memory_hit_rate => { :exp => Regexp.compile(/Memory hits as \% of hit requests:\s+5min:\s+([0-9\.]+)/), :type => 'gauge' },
            :cache_disk_hit_rate => { :exp => Regexp.compile(/Disk hits as \% of hit requests:\s+5min:\s+([0-9\.]+)/), :type => 'gauge' },
            :storage_swap_capcity => { :exp => Regexp.compile(/Storage Swap capacity:\s+([0-9\.]+)\% used/), :type => 'gauge' },
            :cache_miss_service_median => { :exp => Regexp.compile(/Cache Misses:\s+([0-9\.]+)/), :type => 'gauge' },
            :cache_hits_service_median => { :exp => Regexp.compile(/Cache Hits:\s+([0-9\.]+)/), :type => 'gauge' },
            :cache_dns_service_median => { :exp => Regexp.compile(/DNS Lookups:\s+([0-9\.]+)/), :type => 'gauge' },
            :all_requests => { :exp => Regexp.compile(/Number of HTTP requests received:\s+(\d+)/), :type => 'counter' },
            :all_clients => { :exp => Regexp.compile(/Number of clients accessing cache:\s+(\d+)/), :type => 'gauge' },
          }


def collect_data(start_run, args)
  cmdrun = IO.popen("#{args[:path]} -p #{args[:port]} mgr:info")
  stats = cmdrun.read.split("\n")
  cmdrun.close
  stats.each do |line|
    @@regexps.each do |k, v|
      if line =~ v[:exp]
        puts "PUTVAL #{args[:hostname]}/squid/#{v[:type]}-#{k}_#{args[:port]} #{start_run}:#{$1}"
      end
    end
  end
end

while true do
  start_run = Time.now.to_i
  next_run = start_run + args[:interval]
  collect_data(start_run, args)
  while((time_left = (next_run - Time.now.to_i)) > 0) do
    sleep(time_left)
  end
end