app.rb

require 'bundler'
Bundler.require
API_KEY = ""
CF_API_KEY = ''

exit unless Time.now.hour == 3 or Time.now.hour == 15

heroku = PlatformAPI.connect_oauth(API_KEY)
cf = CloudFlare::connection(CF_API_KEY, '[email protected]')

pairs = {
  "kanekure.ssig33.com" => ['kanekure', 'kanekure2'], 
  "music.ssig33.com" => ['ssig33-music', 'ssig33-music2'],
  "ssig33.com" => ['ssig33-site', 'ssig33-site2']
}

pairs.each do |hostname, pair|
  now = nil
  pair.each_with_index{|host, i|
    now = i if heroku.domain.list(host).count == 2
  }
  now = 0 if now == nil
  puts "Now #{hostname}'s Active == #{pair[now]}"
  
  old_heroku = pair[now]
  new_heroku = pair.reject{|x| x == pair[now]}.first

  domain_name = hostname

  heroku.domain.delete(old_heroku, domain_name) rescue nil
  heroku.domain.create(new_heroku, {"hostname" => domain_name})
  
  rec_id = nil
  cf.rec_load_all("ssig33.com")['response']['recs']['objs'].each do |obj|
    rec_id = obj['rec_id'] if obj['name'] == domain_name and obj['type'] == 'CNAME'
  end
  puts "CF Record ID == #{rec_id}"

  cf.rec_edit("ssig33.com", 'CNAME', rec_id, domain_name, "#{new_heroku}.herokuapp.com", 1) 
end

system "wget http://ssig33.com > /dev/null"

Not sure if anything in here is sensitive, but keep in mind this is publicly listed.