rbd: check for volume group existence

Signed-off-by: Praveen M <m.praveen@ibm.com>

Author: iPraveenParihar

internal/rbd/group/util.go

@@ -85,7 +85,9 @@ func (cvg *commonVolumeGroup) generateVolumeGroup(csiID util.CSIIdentifier) erro
 	cvg.namespace = namespace
 	cvg.pool = pool
 
-	return nil
+	_, err = cvg.Exists(context.Background())
+
+	return err
 }
 
 // generateVolumeGroupFromMapping checks the clusterID and poolID mapping and
@@ -229,7 +231,7 @@ func (cvg *commonVolumeGroup) getVolumeGroupAttributes(ctx context.Context) (*jo
 	if attrs.GroupName == "" {
 		log.ErrorLog(ctx, "volume group with id %v not found", cvg.id)
 
-		return nil, ErrRBDGroupNotFound
+		return nil, util.ErrRBDGroupNotFound
 	}
 
 	cvg.requestName = attrs.RequestName
@@ -356,12 +358,12 @@ func (cvg *commonVolumeGroup) GetIOContext(ctx context.Context) (*rados.IOContex
 
 	conn, err := cvg.getConnection(ctx)
 	if err != nil {
-		return nil, fmt.Errorf("%w: failed to connect: %w", ErrRBDGroupNotConnected, err)
+		return nil, fmt.Errorf("%w: failed to connect: %w", util.ErrRBDGroupNotConnected, err)
 	}
 
 	ioctx, err := conn.GetIoctx(cvg.pool)
 	if err != nil {
-		return nil, fmt.Errorf("%w: failed to get IOContext: %w", ErrRBDGroupNotConnected, err)
+		return nil, fmt.Errorf("%w: failed to get IOContext: %w", util.ErrRBDGroupNotConnected, err)
 	}
 
 	if cvg.namespace != "" {
@@ -417,3 +419,13 @@ func (cvg *commonVolumeGroup) GetCreationTime(ctx context.Context) (*time.Time,
 
 	return cvg.creationTime, nil
 }
+
+// Exists checks if the volume group exists in the journal.
+func (cvg *commonVolumeGroup) Exists(ctx context.Context) (bool, error) {
+	_, err := cvg.getVolumeGroupAttributes(context.Background())
+	if err != nil {
+		return false, err
+	}
+
+	return true, nil
+}