func netifKey(key string, n int) string {
	return fmt.Sprintf("%s.%d.%s", cNetifKeyPrefix, n, key)
}
func netifKey(key string, n int) string {
	return fmt.Sprintf("%s.%d.%s", cNetifKeyPrefix, n, key)
}
// netifKey renders a specific network_interface key for a specific resource
// index.