func getDefaultCNINetwork(confDir string) (string, error) {
	files, err := libcni.ConfFiles(confDir, []string{".conf", ".conflist"})
	switch {
	case err != nil:
		return "", err
	case len(files) == 0:
		return "", fmt.Errorf("no networks found in %s", confDir)
	}

	sort.Strings(files)
	for _, confFile := range files {
		var confList *libcni.NetworkConfigList