build(deps): bump github.com/vmware/govmomi from 0.23.0 to 0.26.1

Bumps [github.com/vmware/govmomi](https://github.com/vmware/govmomi) from 0.23.0 to 0.26.1.
- [Release notes](https://github.com/vmware/govmomi/releases)
- [Changelog](https://github.com/vmware/govmomi/blob/master/CHANGELOG.md)
- [Commits](https://github.com/vmware/govmomi/compare/v0.23.0...v0.26.1)

---
updated-dependencies:
- dependency-name: github.com/vmware/govmomi
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/vmware/govmomi/object/virtual_machine.go

@@ -1,5 +1,5 @@
 /*
-Copyright (c) 2015-2017 VMware, Inc. All Rights Reserved.
+Copyright (c) 2015-2021 VMware, Inc. All Rights Reserved.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@ import (
 	"fmt"
 	"net"
 	"path"
+	"strings"
 
 	"github.com/vmware/govmomi/nfc"
 	"github.com/vmware/govmomi/property"
@@ -40,6 +41,34 @@ type VirtualMachine struct {
 	Common
 }
 
+// extractDiskLayoutFiles is a helper function used to extract file keys for
+// all disk files attached to the virtual machine at the current point of
+// running.
+func extractDiskLayoutFiles(diskLayoutList []types.VirtualMachineFileLayoutExDiskLayout) []int {
+	var result []int
+
+	for _, layoutExDisk := range diskLayoutList {
+		for _, link := range layoutExDisk.Chain {
+			for i := range link.FileKey { // diskDescriptor, diskExtent pairs
+				result = append(result, int(link.FileKey[i]))
+			}
+		}
+	}
+
+	return result
+}
+
+// removeKey is a helper function for removing a specific file key from a list
+// of keys associated with disks attached to a virtual machine.
+func removeKey(l *[]int, key int) {
+	for i, k := range *l {
+		if k == key {
+			*l = append((*l)[:i], (*l)[i+1:]...)
+			break
+		}
+	}
+}
+
 func NewVirtualMachine(c *vim25.Client, ref types.ManagedObjectReference) *VirtualMachine {
 	return &VirtualMachine{
 		Common: NewCommon(c, ref),
@@ -181,6 +210,20 @@ func (v VirtualMachine) Clone(ctx context.Context, folder *Folder, name string,
 	return NewTask(v.c, res.Returnval), nil
 }
 
+func (v VirtualMachine) InstantClone(ctx context.Context, config types.VirtualMachineInstantCloneSpec) (*Task, error) {
+	req := types.InstantClone_Task{
+		This: v.Reference(),
+		Spec: config,
+	}
+
+	res, err := methods.InstantClone_Task(ctx, v.c, &req)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewTask(v.c, res.Returnval), nil
+}
+
 func (v VirtualMachine) Customize(ctx context.Context, spec types.CustomizationSpec) (*Task, error) {
 	req := types.CustomizeVM_Task{
 		This: v.Reference(),
@@ -291,7 +334,9 @@ func (v VirtualMachine) WaitForNetIP(ctx context.Context, v4 bool, device ...str
 			devices := VirtualDeviceList(c.Val.(types.ArrayOfVirtualDevice).VirtualDevice)
 			for _, d := range devices {
 				if nic, ok := d.(types.BaseVirtualEthernetCard); ok {
-					mac := nic.GetVirtualEthernetCard().MacAddress
+					// Convert to lower so that e.g. 00:50:56:83:3A:5D is treated the
+					// same as 00:50:56:83:3a:5d
+					mac := strings.ToLower(nic.GetVirtualEthernetCard().MacAddress)
 					if mac == "" {
 						return false
 					}
@@ -327,7 +372,9 @@ func (v VirtualMachine) WaitForNetIP(ctx context.Context, v4 bool, device ...str
 
 			nics := c.Val.(types.ArrayOfGuestNicInfo).GuestNicInfo
 			for _, nic := range nics {
-				mac := nic.MacAddress
+				// Convert to lower so that e.g. 00:50:56:83:3A:5D is treated the
+				// same as 00:50:56:83:3a:5d
+				mac := strings.ToLower(nic.MacAddress)
 				if mac == "" || nic.IpConfig == nil {
 					continue
 				}
@@ -469,6 +516,41 @@ func (v VirtualMachine) RemoveDevice(ctx context.Context, keepFiles bool, device
 	return v.configureDevice(ctx, types.VirtualDeviceConfigSpecOperationRemove, fop, device...)
 }
 
+// AttachDisk attaches the given disk to the VirtualMachine
+func (v VirtualMachine) AttachDisk(ctx context.Context, id string, datastore *Datastore, controllerKey int32, unitNumber int32) error {
+	req := types.AttachDisk_Task{
+		This:          v.Reference(),
+		DiskId:        types.ID{Id: id},
+		Datastore:     datastore.Reference(),
+		ControllerKey: controllerKey,
+		UnitNumber:    &unitNumber,
+	}
+
+	res, err := methods.AttachDisk_Task(ctx, v.c, &req)
+	if err != nil {
+		return err
+	}
+
+	task := NewTask(v.c, res.Returnval)
+	return task.Wait(ctx)
+}
+
+// DetachDisk detaches the given disk from the VirtualMachine
+func (v VirtualMachine) DetachDisk(ctx context.Context, id string) error {
+	req := types.DetachDisk_Task{
+		This:   v.Reference(),
+		DiskId: types.ID{Id: id},
+	}
+
+	res, err := methods.DetachDisk_Task(ctx, v.c, &req)
+	if err != nil {
+		return err
+	}
+
+	task := NewTask(v.c, res.Returnval)
+	return task.Wait(ctx)
+}
+
 // BootOptions returns the VirtualMachine's config.bootOptions property.
 func (v VirtualMachine) BootOptions(ctx context.Context) (*types.VirtualMachineBootOptions, error) {
 	var o mo.VirtualMachine
@@ -579,6 +661,63 @@ func (m snapshotMap) add(parent string, tree []types.VirtualMachineSnapshotTree)
 	}
 }
 
+// SnapshotSize calculates the size of a given snapshot in bytes. If the
+// snapshot is current, disk files not associated with any parent snapshot are
+// included in size calculations. This allows for measuring and including the
+// growth from the last fixed snapshot to the present state.
+func SnapshotSize(info types.ManagedObjectReference, parent *types.ManagedObjectReference, vmlayout *types.VirtualMachineFileLayoutEx, isCurrent bool) int {
+	var fileKeyList []int
+	var parentFiles []int
+	var allSnapshotFiles []int
+
+	diskFiles := extractDiskLayoutFiles(vmlayout.Disk)
+
+	for _, layout := range vmlayout.Snapshot {
+		diskLayout := extractDiskLayoutFiles(layout.Disk)
+		allSnapshotFiles = append(allSnapshotFiles, diskLayout...)
+
+		if layout.Key.Value == info.Value {
+			fileKeyList = append(fileKeyList, int(layout.DataKey)) // The .vmsn file
+			fileKeyList = append(fileKeyList, diskLayout...)       // The .vmdk files
+		} else if parent != nil && layout.Key.Value == parent.Value {
+			parentFiles = append(parentFiles, diskLayout...)
+		}
+	}
+
+	for _, parentFile := range parentFiles {
+		removeKey(&fileKeyList, parentFile)
+	}
+
+	for _, file := range allSnapshotFiles {
+		removeKey(&diskFiles, file)
+	}
+
+	fileKeyMap := make(map[int]types.VirtualMachineFileLayoutExFileInfo)
+	for _, file := range vmlayout.File {
+		fileKeyMap[int(file.Key)] = file
+	}
+
+	size := 0
+
+	for _, fileKey := range fileKeyList {
+		file := fileKeyMap[fileKey]
+		if parent != nil ||
+			(file.Type != string(types.VirtualMachineFileLayoutExFileTypeDiskDescriptor) &&
+				file.Type != string(types.VirtualMachineFileLayoutExFileTypeDiskExtent)) {
+			size += int(file.Size)
+		}
+	}
+
+	if isCurrent {
+		for _, diskFile := range diskFiles {
+			file := fileKeyMap[diskFile]
+			size += int(file.Size)
+		}
+	}
+
+	return size
+}
+
 // FindSnapshot supports snapshot lookup by name, where name can be:
 // 1) snapshot ManagedObjectReference.Value (unique)
 // 2) snapshot name (may not be unique)
@@ -855,8 +994,10 @@ func (v VirtualMachine) UUID(ctx context.Context) string {
 	if err != nil {
 		return ""
 	}
-
-	return o.Config.Uuid
+	if o.Config != nil {
+		return o.Config.Uuid
+	}
+	return ""
 }
 
 func (v VirtualMachine) QueryChangedDiskAreas(ctx context.Context, baseSnapshot, curSnapshot *types.ManagedObjectReference, disk *types.VirtualDisk, offset int64) (types.DiskChangeInfo, error) {