Transform ActiveMQ config files into a connection diagram for Graphviz

amq-mapper.rb

#!/usr/bin/env ruby

# Generate a DOT file showing links between ActiveMQ brokers using
# a list of activemq.xml files passed as ARGV.

require 'rexml/document'
require 'erb'

broker_map = Hash.new

ARGV.each do |f|
  doc = REXML::Document.new(File.read(f))

  broker = REXML::XPath.first(doc, '//broker').attribute('brokerName').value
  connections = REXML::XPath.match(doc, '//networkConnector')

  connection_map = connections.inject(Hash.new) do |map, entry|
    dest = entry.attribute('uri').value.match(/([^\/]+):61616/).captures.first
    duplex = if entry.attribute('duplex').value == 'true'
      true
    else
      false
    end
    
    map[dest] = duplex
    map
  end

  broker_map[broker] = connection_map
end

dot_template = ERB.new(<<-EOT, nil, '<>')
digraph amq_broker_map {
  overlap=scale;
  concentrate=false;
  splines=true;

<% broker_map.each do |source, target_hash| %>
<% target_hash.each do |target, duplex| %>
<% if duplex %>
  "<%= source %>" -> "<%= target %>" [dir="both"]
<% else %>
  "<%= source %>" -> "<%= target %>"
<% end %>
<% end %>

<% end %>
}
EOT

File.write('amq_broker_map.dot', dot_template.result(binding))