Munin contributed plugins

#!/usr/bin/env ruby

# encoding: utf-8

# Plugin to monitor Room Alert 11E environmental units.

# Requires ruby and the ruby SNMP library.

#

# Written by Phil Gold <phil_g@pobox.com>.

#

# Usage: Copy or link into /etc/munin/node.d/.  End word can be either

#        "temperature" or "humidity".

#

# Parameters:

#

# 	config   (required)

# 	autoconf (optional - used by munin-config)

#

# Config variables:

#

#       units     - DNS names of environmental units

#       community - Community to use to access the Room Alert unit

#                   Defaults to 'public'.

#       variables of the form label_<unit>_<num>, where dots and dashes in the

#         unit names are replaced with underscores - labels for specific sensors

#         in the unit.

#         e.g. env.label_192_168_1_115_2 Main Unit

#

# Example config:

#

#       [room_alert_*]

#       env.units unit1.example.com unit2.example.com

#       env.community private

#       env.label_unit1_example_com_2 Main Unit

#       env.label_unit1_example_com_3 Rack 2 Sensor

require 'snmp'

base_oid = "enterprises.20916.1.3.1"

case $0.match('[^_]+$')[0]

when "temperature"

  subchannel = 1

  name = "temperature"

  label = "°C"

  letter = "t"

when "humidity"

  subchannel = 3

  name = "humidity"

  label = "% Relative Humidity"

  letter = "h"

else

  exit 1

end

def is_vb_valid(vb, subchannel)

  return (vb.name[-1] == 0 and vb.name[-2] == subchannel and vb.value > 1)

end

def field_name(unit, vb, letter)

  clean_unit = unit.gsub(/[.-]/, '_')

  sensor = vb.name[-3].to_s

  return "#{clean_unit}_#{letter}#{sensor}"

end

def label(unit, vb)

  clean_unit = unit.gsub(/[.-]/, '_')

  sensor = vb.name[-3].to_s

  label = "#{unit} " + (ENV["label_#{clean_unit}_#{sensor}"] || "sensor #{sensor}")

end

units = (ENV['units'] || "").split(/\s+/)

community = ENV['community'] || "public"

case ARGV[0]

when "autoconf"

  puts "no"

  exit 0

when "config"

  puts "graph_title Room Alert 11E units (#{name} probes)"

  puts "graph_vlabel #{label}"

  puts "graph_category sensors"

  if name == "humidity"

    puts "graph_args --lower-limit 0 --upper-limit 100"

  end

  units.each do |unit|

    SNMP::Manager.open(:Host => unit,

                       :Community => community,

                       :Version => :SNMPv1) do |manager|

      manager.walk(base_oid) do |vb|

        if not is_vb_valid(vb, subchannel)

          next

        end

        puts "#{field_name(unit, vb, letter)}.label #{label(unit, vb)}"

      end

    end

  end

  exit 0

end

units.each do |unit|

  SNMP::Manager.open(:Host => unit,

                     :Community => community,

                     :Version => :SNMPv1) do |manager|

    manager.walk(base_oid) do |vb|

      if not is_vb_valid(vb, subchannel)

        next

      end

      puts "#{field_name(unit, vb, letter)}.value #{vb.value.to_f / 100}"

    end

  end

end