dozens_dns_update.rb

require 'dozens'
require 'resolv'

user = 'hoge'
apikey = 'fuga'

def update_a(domain, sub)
  if sub == "" then
    whole = domain
  else
    whole = "#{sub}.#{domain}"
  end

  # check if ip address is updated
  dns_ip = ""

  begin
    dns_ip = Resolv.getaddress(whole)
  rescue Resolv::ResolvError
  end

  current_ip = `curl http://ieserver.net/ipcheck.shtml`
  exit if dns_ip == current_ip


  # update DNS info
  api = Dozens::API.new(user, apikey)
  api.authenticate

  recordid = nil
  records = api.records(domain)

  if records != [] then
    for x in records["record"] do
      if x["name"] == whole && x["type"] = "A" then
        recordid = x["id"]
        break
      end
    end
  end

  if recordid then
    api.update_record(recordid, {"content" => current_ip})
  else
    api.create_record({"domain" => domain,
                       "name" => sub,
                       "type" => "A",
                       "content" => current_ip})
  end
end