Parser for Amazon EC2 Public IP Range Announcements

ec2-ip-ranger.rb

#!/usr/bin/env ruby 
# Parser for Amazon EC2 Public IP Range Announcements
# Author: Christoph Thiel <cthiel@suse.com>
# Date: 2011-09-23

require 'rubygems'
require 'bundler/setup'
require 'nokogiri'
require 'open-uri'
require 'netaddr'

regexp = /(US East|US West|EU|Singapore|Tokyo)|(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\/\d{1,2})/

if ARGV.first.nil?
  puts "Usage:\n  ./ec2-ip-ranger.rb https://forums.aws.amazon.com/ann.jspa?annID=1182"
  exit 1
end

url = ARGV.first
page = Nokogiri::HTML(open(url))

debug = ARGV.last.eql?('-d')

region_map = { 'US East' => 'us-east-1',
               'US West' => 'us-west-1',
               'EU' => 'eu-west-1',
               'Singapore' => 'ap-southeast-1',
               'Tokyo' => 'ap-northeast-1'
             }
ip_map = {}
size_map = {}
current_region = ''

page.css(".jive-body").text.strip.gsub(/\\n/,' ').scan(regexp) do |match|
  
  if match[1].nil?

    if !current_region.empty? and debug
      puts region_map[current_region] + ": " + size_map[region_map[current_region]].to_s + " hosts"
    end
    
    current_region = match[0]
    ip_map.merge!({region_map[current_region] => []})
    size_map.merge!({region_map[current_region] => 0})
  elsif match[0].nil?
    ip_map[region_map[current_region]] << match[1]
    size_map[region_map[current_region]] += NetAddr::CIDR.create(match[1]).size

    puts region_map[current_region] + ": " + match[1] if debug
  end
end

puts region_map[current_region] + ": " + size_map[region_map[current_region]].to_s + " hosts" if debug

unless debug
  ip_map.each do |region, ips|
    puts "[#{region}]"
    sorted_ips = ips.sort_by{|i| i.split('.').first.to_i }.join(' ')
    puts "public-ips=\"#{sorted_ips}\""
  end
end

Gemfile

source :rubygems

gem 'nokogiri'
gem 'netaddr'