Add volume readiness check and corresponding tests for 'CreateVolume'

This commit introduces a new function, 'waitForVolumeAvailability', to the 'CreateVolume' function of our CSI driver. This function ensures that a volume reaches the 'Available' state before the 'CreateVolume' request is completed. To validate this functionality, corresponding tests have been added. This enhancement improves reliability and provides clearer error messages for debugging.

pkg/driver/constants.go

@@ -15,6 +15,8 @@
 package driver
 
 import (
+	"time"
+
 	"github.com/onmetal/onmetal-csi-driver/pkg/utils"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
@@ -46,4 +48,10 @@ const (
 	CSIDriverName    = "csi.onmetal.de"
 	topologyKey      = "topology." + CSIDriverName + "/zone"
 	volumeFieldOwner = client.FieldOwner("csi.onmetal.de/volume")
+
+	// Constants for volume polling mechanism
+
+	waitVolumeInitDelay   = 1 * time.Second // Initial delay before starting to poll for volume status
+	waitVolumeFactor      = 1.1             // Factor by which the delay increases with each poll attempt
+	waitVolumeActiveSteps = 5               // Number of consecutive active steps to wait for volume status change
 )

pkg/driver/controller.go

@@ -31,6 +31,7 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/klog/v2"
 	"k8s.io/utils/pointer"
 	"sigs.k8s.io/controller-runtime/pkg/client"
@@ -129,7 +130,12 @@ func (d *driver) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest)
 	if err := d.onmetalClient.Patch(ctx, volume, client.Apply, volumeFieldOwner, client.ForceOwnership); err != nil {
 		return nil, status.Errorf(codes.Internal, "Failed to patch volume %s: %v", client.ObjectKeyFromObject(volume), err)
 	}
-	klog.InfoS("Applied volume", "Volume", client.ObjectKeyFromObject(volume))
+
+	if err := waitForVolumeAvailability(ctx, d.onmetalClient, volume); err != nil {
+		return nil, fmt.Errorf("failed to confirm availability of the volume: %w", err)
+	}
+
+	klog.InfoS("Volume applied and is now available", "Volume", client.ObjectKeyFromObject(volume))
 
 	return &csi.CreateVolumeResponse{
 		Volume: &csi.Volume{
@@ -148,6 +154,31 @@ func (d *driver) CreateVolume(ctx context.Context, req *csi.CreateVolumeRequest)
 	}, nil
 }
 
+// waitForVolumeAvailability is a helper function that waits for a volume to become available.
+// It uses an exponential backoff strategy to periodically check the status of the volume.
+// The function returns an error if the volume does not become available within the specified number of attempts.
+func waitForVolumeAvailability(ctx context.Context, onmetalClient client.Client, volume *storagev1alpha1.Volume) error {
+	backoff := wait.Backoff{
+		Duration: waitVolumeInitDelay,
+		Factor:   waitVolumeFactor,
+		Steps:    waitVolumeActiveSteps,
+	}
+
+	err := wait.ExponentialBackoffWithContext(ctx, backoff, func(ctx context.Context) (bool, error) {
+		err := onmetalClient.Get(ctx, client.ObjectKey{Namespace: volume.Namespace, Name: volume.Name}, volume)
+		if err == nil && volume.Status.State == storagev1alpha1.VolumeStateAvailable {
+			return true, nil
+		}
+		return false, err
+	})
+
+	if wait.Interrupted(err) {
+		return fmt.Errorf("volume %s did not reach 'Available' state within the defined timeout: %w", client.ObjectKeyFromObject(volume), err)
+	}
+
+	return err
+}
+
 func (d *driver) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest) (*csi.DeleteVolumeResponse, error) {
 	klog.InfoS("Deleting volume", "Volume", req.GetVolumeId())
 	if req.GetVolumeId() == "" {
@@ -162,7 +193,7 @@ func (d *driver) DeleteVolume(ctx context.Context, req *csi.DeleteVolumeRequest)
 	if err := d.onmetalClient.Delete(ctx, vol); err != nil {
 		return nil, status.Errorf(codes.Internal, "Failed to delete volume %s: %v", client.ObjectKeyFromObject(vol), err)
 	}
-	klog.InfoS("Deleted deleted volume", "Volume", req.GetVolumeId())
+	klog.InfoS("Deleted volume", "Volume", req.GetVolumeId())
 	return &csi.DeleteVolumeResponse{}, nil
 }