docs: def update_dns(config, record, sa_version):
      "Update the DNS record"
      try:
          domain = config.get('domain_name', 'sa.baruwa.com.')
          dns_key = config.get('domain_key')
          dns_ip = config.get('domain_ip', '127.0.0.1')
          keyring = tsigkeyring.from_text({domain: dns_key})
          transaction = update.Update(
              domain,
              keyring=keyring,
              keyalgorithm=tsig.HMAC_SHA512)
          txtrecord = '%s.%s' % (sa_version, domain)
          transaction.replace(txtrecord, 120, 'txt', record)
          query.tcp(transaction, dns_ip)
          return True
      except DNSException, msg:
          raise SaChannelUpdateDNSError(msg)