Gets list of currently included packages in the Cedar-14 stack

get_cedar_packages.rb

require 'mechanize'

mechanize = Mechanize.new

page = mechanize.get('https://devcenter.heroku.com/articles/cedar-ubuntu-packages')
rows = page.xpath('/html/body/div/div/div/article/table/tr')
pkgs = rows.map {|r| r.xpath('td').map {|e| e.text.strip}}

pkgs.each do |pkg|
  if pkg[2] != "absent"
    puts pkg[0]
  end
end