UUID generation for disks in NDM

uuid.go

// gets the uuid of the provided disk
func getUid(device *udev.UdevDevice) string {
	uid := device.GetPropertyValue(udev.UDEV_WWN) +
		device.GetPropertyValue(udev.UDEV_MODEL) +
		device.GetPropertyValue(udev.UDEV_SERIAL) +
		device.GetPropertyValue(udev.UDEV_VENDOR)


	idtype := device.GetPropertyValue(udev.UDEV_TYPE)

	model := device.GetPropertyValue(udev.UDEV_MODEL)

	// in case of virtual of ephemeral we go with the gpt label (partition label in general),
	// if it is also not available check for filesystem label. Or should we?
	localDiskModels := make([]string, 0)
	localDiskModels = append(localDiskModels, "EphemeralDisk")
	localDiskModels = append(localDiskModels, "Virtual_disk")
	if len(idtype) == 0 || util.Contains(localDiskModels, model) {
		
		gptLabel := device.GetPropertyValue(udev.UDEV_PART_TABLE)
		fsLabel := device.GetPropertyValue(udev.UDEV_FS_UUID)
		if gptLabel == "" {
			if fsLabel == "" {
				// we have no way to uniquely identify the disk.
			} else {
				uid = fsLabel
			}
		} else {
			uid = gptLabel
		}
	}
  
  // take an md5 hash of the uid and return
	return util.Hash(uid)
}