feat: support blk UUID in preset

blk/blk.go

@@ -98,8 +98,11 @@ type Mounter struct {
 
 func NewMounterFromPreset(p *mnt.Preset) (mnt.Mounter, error) {
 	preset := *p
-	if preset.Path == "" {
-		return nil, errors.New("preset path is empty")
+	if preset.Path == "" && preset.UUID == "" {
+		return nil, errors.New("preset path and uuid cannot be both empty")
+	}
+	if preset.UUID != "" && !IsValidUUID(preset.UUID) {
+		return nil, errors.New("invalid UUID")
 	}
 	if !util.IsValidMountPoint(preset.MountPoint) {
 		return nil, errors.Errorf("invalid mount point %q", preset.MountPoint)
@@ -114,7 +117,12 @@ func NewMounterFromPreset(p *mnt.Preset) (mnt.Mounter, error) {
 }
 
 func (m *Mounter) refresh() error {
-	devs, err := List(m.preset.Path)
+	queryPath := m.preset.Path
+	if m.preset.UUID != "" {
+		queryPath = "/dev/disk/by-uuid/" + m.preset.UUID
+	}
+
+	devs, err := List(queryPath)
 	if err != nil {
 		return errors.Wrap(err, 0)
 	}

blk/uuid.go

@@ -0,0 +1,9 @@
+package blk
+
+import "regexp"
+
+var blkUuidPattern = regexp.MustCompile("^[0-9a-zA-Z-]+$")
+
+func IsValidUUID(uuid string) bool {
+	return blkUuidPattern.MatchString(uuid)
+}

mnt/preset.go

@@ -16,6 +16,7 @@ type Preset struct {
 	Name       string `yaml:"name"`
 	Type       string `yaml:"type"`
 	Path       string `yaml:"path"`
+	UUID       string `yaml:"uuid"`
 	MountPoint string `yaml:"mountpoint"`
 
 	AuthCmd  string `yaml:"auth_cmd"` // e.g. for loading the encryption key