vsphere: check if volume exists before create

Sometimes, volume creation can succeed right as the request times out,
causing k8s to interpret it as a failure. When the request is retried,
we want it to succeed. When trying this in vSphere, the second create
request failed with "already exists" and it never recovered.

This adds a check to the in-tree vsphere storage plugin that checks if a
VMDK exists before trying to create it. The check is done BEFORE create.

Tested: manual only )-:

Author: Jonathan Basseri

staging/src/k8s.io/legacy-cloud-providers/vsphere/vclib/diskmanagers/vdm.go

@@ -39,18 +39,26 @@ func (diskManager virtualDiskManager) Create(ctx context.Context, datastore *vcl
 	if diskManager.volumeOptions.SCSIControllerType == "" {
 		diskManager.volumeOptions.SCSIControllerType = vclib.LSILogicControllerType
 	}
-	// Create virtual disk
-	diskFormat := vclib.DiskFormatValidType[diskManager.volumeOptions.DiskFormat]
-	// Create a virtual disk manager
-	vdm := object.NewVirtualDiskManager(datastore.Client())
+
+	// Check for existing VMDK before attempting create. Because a name collision
+	// is unlikely, "VMDK already exists" is likely from a previous attempt to
+	// create this volume.
+	if dsPath := vclib.GetPathFromVMDiskPath(diskManager.diskPath); datastore.Exists(ctx, dsPath) {
+		klog.V(2).Infof("Create: VirtualDisk already exists, returning success. Name=%q", diskManager.diskPath)
+		return diskManager.diskPath, nil
+	}
+
 	// Create specification for new virtual disk
+	diskFormat := vclib.DiskFormatValidType[diskManager.volumeOptions.DiskFormat]
 	vmDiskSpec := &types.FileBackedVirtualDiskSpec{
 		VirtualDiskSpec: types.VirtualDiskSpec{
 			AdapterType: diskManager.volumeOptions.SCSIControllerType,
 			DiskType:    diskFormat,
 		},
 		CapacityKb: int64(diskManager.volumeOptions.CapacityKB),
 	}
+
+	vdm := object.NewVirtualDiskManager(datastore.Client())
 	requestTime := time.Now()
 	// Create virtual disk
 	task, err := vdm.CreateVirtualDisk(ctx, diskManager.diskPath, datastore.Datacenter.Datacenter, vmDiskSpec)