util.go

package main

import (
	"errors"
	"fmt"
	"os"
	"os/exec"
	"slices"
	"time"
)

var filesystems []string = []string{
	"btrfs",
	"ext2",
	"ext3",
	"ext4",
	"fat",
	"fat32",
	"ntfs",
	"xfs",
}

func getFilesystemType(dev string) (string, error) {
	out, err := exec.Command("blkid", "-s", "TYPE", "-o", "value", dev).CombinedOutput()

	if err != nil {
		if len(out) == 0 {
			return "", nil
		}

		return "", errors.New(string(out))
	}

	return string(out), nil
}

func formatFilesystem(dev, label, filesystem string) error {
	_, err := exec.LookPath("mkfs." + filesystem)
	if err != nil || !slices.Contains(filesystems, filesystem) {
		return errors.New(fmt.Sprintf("filesystem '%s' does not exist", filesystem))
	}

	out, err := exec.Command(fmt.Sprintf("mkfs.%s", filesystem), "-L", label, dev).CombinedOutput()
	if err != nil {
		return errors.New(string(out))
	}

	return nil
}

func findDeviceWithTimeout(volId string) (string, error) {
	devicePaths := []string{
		"/dev/disk/by-id/scsi-0QEMU_QEMU_HARDDISK_%s",
		"/dev/disk/by-id/virtio-%.20s",
	}

	for i := 1; i <= 10; i++ {
		time.Sleep(500 * time.Millisecond)
		for _, devicePath := range devicePaths {
			dev := fmt.Sprintf(devicePath, volId)
			if _, err := os.Stat(dev); err != nil {
				if !os.IsNotExist(err) {
					return "", err
				}
			} else {
				return dev, nil
			}
		}
	}

	return "", fmt.Errorf("Block device not found")
}

func isDirectoryPresent(path string) (bool, error) {
	stat, err := os.Stat(path)

	if os.IsNotExist(err) {
		return false, nil
	} else if err != nil {
		return false, err
	} else {
		return stat.IsDir(), nil
	}
}