rbd: add support for rbd striping

RBD supports creating rbd images with
object size, stripe unit and stripe count
to support striping. This PR adds the support
for the same.

More details about striping at
https://docs.ceph.com/en/quincy/man/8/rbd/#striping

fixes: #3124

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

e2e/rbd_helper.go

@@ -942,3 +942,69 @@ func waitToRemoveImagesFromTrash(f *framework.Framework, poolName string, t int)
 
 	return err
 }
+
+// imageInfo strongly typed JSON spec for image info.
+type imageInfo struct {
+	Name        string `json:"name"`
+	StripeUnit  int    `json:"stripe_unit"`
+	StripeCount int    `json:"stripe_count"`
+	ObjectSize  int    `json:"object_size"`
+}
+
+// getImageInfo queries rbd about the given image and returns its metadata, and returns
+// error if provided image is not found.
+func getImageInfo(f *framework.Framework, imageName, poolName string) (imageInfo, error) {
+	// rbd --format=json info [image-spec | snap-spec]
+	var imgInfo imageInfo
+
+	stdOut, stdErr, err := execCommandInToolBoxPod(
+		f,
+		fmt.Sprintf("rbd info %s %s --format json", rbdOptions(poolName), imageName),
+		rookNamespace)
+	if err != nil {
+		return imgInfo, fmt.Errorf("failed to get rbd info: %w", err)
+	}
+	if stdErr != "" {
+		return imgInfo, fmt.Errorf("failed to get rbd info: %v", stdErr)
+	}
+	err = json.Unmarshal([]byte(stdOut), &imgInfo)
+	if err != nil {
+		return imgInfo, fmt.Errorf("unmarshal failed: %w. raw buffer response: %s",
+			err, stdOut)
+	}
+
+	return imgInfo, nil
+}
+
+// validateStripe validate the stripe count, stripe unit and object size of the
+// image.
+func validateStripe(f *framework.Framework,
+	pvc *v1.PersistentVolumeClaim,
+	stripeUnit,
+	stripeCount,
+	objectSize int,
+) error {
+	imageData, err := getImageInfoFromPVC(pvc.Namespace, pvc.Name, f)
+	if err != nil {
+		return err
+	}
+
+	imgInfo, err := getImageInfo(f, imageData.imageName, defaultRBDPool)
+	if err != nil {
+		return err
+	}
+
+	if imgInfo.ObjectSize != objectSize {
+		return fmt.Errorf("objectSize %d does not match expected %d", imgInfo.ObjectSize, objectSize)
+	}
+
+	if imgInfo.StripeUnit != stripeUnit {
+		return fmt.Errorf("stripeUnit %d does not match expected %d", imgInfo.StripeUnit, stripeUnit)
+	}
+
+	if imgInfo.StripeCount != stripeCount {
+		return fmt.Errorf("stripeCount %d does not match expected %d", imgInfo.StripeCount, stripeCount)
+	}
+
+	return nil
+}