backup operator: fixed incorrect backup file naming convention.

When limiting the number of backups, if the revision would move to needing another digit, the logic would never select a new entry as _ is > to 9 in ascii terms.

Note that this is backwards incompatible as now files receive a correct padding and old revisions will still be incorrectly handled.

Author: kapouille

pkg/backup/backup_manager.go

@@ -73,7 +73,7 @@ func (bm *BackupManager) SaveSnap(ctx context.Context, s3Path string, isPeriodic
 	}
 	defer rc.Close()
 	if isPeriodic {
-		s3Path = fmt.Sprintf(s3Path+"_v%d_%s", rev, now.Format("2006-01-02-15:04:05"))
+		s3Path = fmt.Sprintf(s3Path+"_v%019d_%s", rev, now.Format("2006-01-02-15:04:05"))
 	}
 	_, err = bm.bw.Write(ctx, s3Path, rc)
 	if err != nil {