Munin plugin for Virgin Media Superhub

vm_superhub.rb

#!/usr/local/bin/ruby

Host = '192.168.100.1'

require 'net/http'
require 'timeout'
def get(page)
  Timeout.timeout(5) { Net::HTTP.get(Host, page) }
rescue => e
  STDERR.puts "GET http://#{Host}/#{page} failure: #{e.class}: #{e.message}"
  nil
end

def nums_from_table(html, heading)
  if html and html =~ /#{Regexp.escape(heading)}<\/td>\s+(.+?)<\/tr>/im
    $1.scan(/(?<=<td>)\s*-?[0-9]+(?:\.[0-9]+)?/im).map(&:to_f)
  else
    []
  end
end

which = $0
category = /(?:downstream_(?:power|mer)|upstream_power)$/.match(which)[0] rescue
  abort("Invalid name '#{$0}': must be one of downstream_power, downstream_mer, upstream_power")

Value = Struct.new(:name, :type, :label, :value)
values = []

title = nil
vlabel = nil
info = nil
max_down = 8
max_up = 4

if category.start_with? 'downstream_'
  html = get('/cgi-bin/VmRouterStatusDownstreamCfgCgi')

  case category
  when 'downstream_power'
    title = "Downstream Power Levels"
    info = "Downstream power levels in dBmV. Closer to zero is better, must be within +/- 15."
    vlabel = "dBmV"

    chans = nums_from_table(html, "Power Level (dBmV)")
    max_down.times do |chan|
      val = chans[chan] || 'U'
      values << Value.new("down_dbmv#{chan+1}", 'GAUGE', "DS-#{chan+1} Power (dBmV)", val)
    end
  when 'downstream_mer'
    title = "Downstream MER"
    info = "Downstream modulation error ratio. 30dB minimum, ideally 33+." # (with 256 QAM)
    vlabel = "dB"
    chans = nums_from_table(html, "RxMER (dB)")

    max_down.times do |chan|
      val = chans[chan] || 'U'
      values << Value.new("down_mer#{chan+1}", 'GAUGE', "DS-#{chan+1} MER (dB)", val)
    end
  end
elsif category == 'upstream_power'
  title = "Upstream Power Level"
  vlabel = "dBmV"
  info = "Upstream power levels in dBmV. Lower the better, must be under 55."
  html = get('/cgi-bin/VmRouterStatusUpstreamCfgCgi')
  chans = nums_from_table(html, "Power Level (dBmV)")#.each_with_index do |val,chan|
  max_up.times do |chan|
    val = chans[chan] || 'U'
    values << Value.new("up_dbmv#{chan+1}", 'GAUGE', "US-#{chan+1} Power (dBmV)", val)
  end
end

case ARGV.first
when 'config'
  puts <<EOC
graph_title Cable Modem #{title}
graph_vlabel #{vlabel}
graph_category cablemodem
graph_info #{info}
graph_order #{values.map(&:name).join ' '}}
EOC
  values.each do |v|
    puts <<EOC
#{v.name}.label #{v.label}
#{v.name}.type #{v.type}
EOC
  end
when 'autoconfig'
  puts(values.any? ? 'yes' : 'no')
else
  exit 1 unless values.any?
  values.each {|v| puts "#{v.name}.value #{v.value}"}
end