Fix bug we initiate a backup when the volume has started detaching

When the volume.Spec.NodeID is different than the node ID of the backup
VA ticket, we should not initiate a backup as the volume is going to
detach soon

longhorn-7937

Signed-off-by: Phan Le <phan.le@suse.com>

controller/backup_controller.go

@@ -531,8 +531,9 @@ func (bc *BackupController) VerifyAttachment(backup *longhorn.Backup, volumeName
 	}
 
 	attachmentTicketID := longhorn.GetAttachmentTicketID(longhorn.AttacherTypeBackupController, backup.Name)
+	isVolumeStillDesiredToAttachToSameNodeAsAttachmentTicket := vol.Spec.NodeID == longhorn.GetNodeIdOfAttachmentTicket(attachmentTicketID, va)
 
-	return longhorn.IsAttachmentTicketSatisfied(attachmentTicketID, va), nil
+	return isVolumeStillDesiredToAttachToSameNodeAsAttachmentTicket && longhorn.IsAttachmentTicketSatisfied(attachmentTicketID, va), nil
 }
 
 func (bc *BackupController) isResponsibleFor(b *longhorn.Backup, defaultEngineImage string) (bool, error) {

k8s/pkg/apis/longhorn/v1beta2/volumeattachment.go

@@ -123,6 +123,18 @@ func GetAttachmentTicketID(attacherType AttacherType, id string) string {
 	return retID
 }
 
+func GetNodeIdOfAttachmentTicket(attachmentID string, va *VolumeAttachment) string {
+	if va == nil {
+		return ""
+	}
+	attachmentTicket, ok := va.Spec.AttachmentTickets[attachmentID]
+	if !ok {
+		return ""
+	}
+
+	return attachmentTicket.NodeID
+}
+
 func IsAttachmentTicketSatisfied(attachmentID string, va *VolumeAttachment) bool {
 	if va == nil {
 		return false