haproxy.rb

#!/usr/bin/env ruby
## Rackspace Cloud Monitoring Plug-In
## HAProxy Stats
#
# ----------------------------------------------------------------------------
# "THE BEER-WARE LICENSE" (Revision 42):
# <lo@petalphile.com> wrote this file. As long as you retain this notice you
# can do whatever you want with this stuff. If we meet some day, and you think
# this stuff is worth it, you can buy me a beer in return
# ----------------------------------------------------------------------------
#
# haproxy.rb
#  - Takes HAProxy stats and grabs connections, rate, and check time
#    for every listener and every backend server, and prints it using
#    Rackspace Cloud Montioring metric lines
#
# Usage:
# Place plug-in in /usr/lib/rackspace-monitoring-agent/plugins
#
# The following is an example 'criteria' for a Rackspace Monitoring Alarm:
#
# if (metric['connections'] == 0) {
#   return new AlarmStatus(CRITICAL, 'No connections to your HAProxy!
#
# if (metric['connections'] < '10') {
#   return new AlarmStatus(WARNING, 'Less than 10 connections to your HAProxy!');
# }
#
# return new AlarmStatus(OK, 'HAProxy connections normal');
#
# Please note that you will need to adjust the thresholds based on workload.
# Also, there are other metrics this plugin reports you may find useful, but
# the metricnames for these will vary based on your HAProxy cluster name.
#

def fail(status = 'Unknown failure')
  puts "status #{status}"
  exit 1
end

def metric(name, type, value)
  @metrics[name] = {
    :type => type,
    :value => value
  }
end

def output_success
  puts 'status HAProxy is running and reporting metrics'
  @metrics.each do |name, v|
    puts "metric #{name} #{v[:type]} #{v[:value]}"
  end
end

begin
  require 'optparse'
  require 'socket'
rescue
  fail 'Failed to load required ruby gems'
end

@metrics = {}
options = {
    :limit => 10
}

args = ARGV.dup

OptionParser.new do |o|
  o.banner = "Usage: #{$PROGRAM_NAME} [options]"
  o.on('-s', '--stats-socket SOCKET', 'Specify the HAProxy stats socket') do |s|
    options[:sock] = s
  end
  o.on('-l', '--limit BACKEND_COUNT', 'Specify a limit of how many backends to report. Default is 10.') do |l|
    options[:limit] = l.to_i
  end
  o.on_tail('-h', '--help', 'Show this message') { puts o; exit }
  o.parse!(args)
end

fail 'You must specify the haproxy stats socket' if options[:sock].nil?

pid = `pidof haproxy`.chomp.to_i || fail('HAProxy is not running')

# get global frontend stats
begin
  ctl = UNIXSocket.new(options[:sock])
  ctl.puts 'show info'

  while (line = ctl.gets)
    if line =~ /^CurrConns:/
      line = line.split(':')
      metric('connections', 'int', line[1].to_i)
    end
    if line =~ /^ConnRate:/
      line = line.split(':')
      metric('connection_rate', 'int', line[1].to_i)
    end
  end
  ctl.close
rescue
  fail "Problem reading global stats from #{options[:sock]}"
end

# get per-backend stats
begin
  ctl = UNIXSocket.new(options[:sock])
  ctl.puts 'show stat'

  i = 0
  while (line = ctl.gets)
    next unless line =~ /^[^#]\w+/
    line = line.split(',')
    host = "#{line[0]}_#{line[1]}".tr('-', '_').tr('.', '_')
    if i < options[:limit]
      metric("#{host}_request_rate", 'int', line[47].to_i)
      metric("#{host}_total_requests", 'gauge', line[49].to_i)
      metric("#{host}_current_queue", 'int', line[3].to_i)
      metric("#{host}_health_check_duration","int",line[35].to_i)
      i += 1
    end
  end
  ctl.close
rescue
  fail "Problem reading backend stats from #{options[:sock]}"
end

output_success