add max volume size feature

README.md

@@ -23,7 +23,7 @@
 ## Description
 CSI Driver for Unity XT is part of the [CSM (Container Storage Modules)](https://github.com/dell/csm) open-source suite of Kubernetes storage enablers for Dell products. CSI Driver for Unity XT is a Container Storage Interface (CSI) driver that provides support for provisioning persistent storage using Dell Unity XT storage array. 
 
-It supports CSI specification version 1.5.
+It supports CSI specification version 1.6.
 
 This project may be compiled as a stand-alone binary using Golang that, when run, provides a valid CSI endpoint. It also can be used as a precompiled container image.
 

service/controller.go

@@ -31,6 +31,7 @@ import (
 	"golang.org/x/net/context"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/wrapperspb"
 )
 
 const (
@@ -523,20 +524,41 @@ func (s *service) GetCapacity(
 
 	metricsAPI := gounity.NewMetrics(unity)
 
-	resp, err := metricsAPI.GetCapacity(ctx)
+	capacity, err := metricsAPI.GetCapacity(ctx)
 
 	if err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 
-	log.Infof("Available capacity from the Array: %d", resp.Entries[0].Content.SizeFree)
+	log.Infof("Available capacity from the Array: %d", capacity.Entries[0].Content.SizeFree)
+
+	maxVolSize := s.getMaximumVolumeSize(ctx, arrayID)
+
+	if maxVolSize == 0 {
+		return &csi.GetCapacityResponse{
+			AvailableCapacity: int64(capacity.Entries[0].Content.SizeFree),
+		}, nil
+	}
 
 	return &csi.GetCapacityResponse{
-		AvailableCapacity: int64(resp.Entries[0].Content.SizeFree),
+		AvailableCapacity: int64(capacity.Entries[0].Content.SizeFree),
+		MaximumVolumeSize: wrapperspb.Int64(maxVolSize),
 	}, nil
 
 }
 
+func (s *service) getMaximumVolumeSize(ctx context.Context, arrayID string) int64 {
+	ctx, log, _ := GetRunidLog(ctx)
+	unity, err := s.getUnityClient(ctx, arrayID)
+	volumeAPI := gounity.NewVolume(unity)
+	maxVolumeSize, err := volumeAPI.GetMaxVolumeSize(ctx, "Limit_MaxLUNSize")
+	if err != nil {
+		log.Debugf("GetMaxVolumeSize returning: %v for Array having GlobalId %s", err, arrayID)
+		return 0
+	}
+	return maxVolumeSize
+}
+
 func (s *service) CreateSnapshot(ctx context.Context, req *csi.CreateSnapshotRequest) (*csi.CreateSnapshotResponse, error) {
 	ctx, log, rid := GetRunidLog(ctx)
 	log.Debugf("Executing CreateSnapshot with args: %+v", *req)