Use *string for backingObjectId

BackingObjectId is an optional value which means there is a
distinction between unset and empty value.
The serialization process treats empty value as unset, which
means it is changing the content between serialize/deserialize.
Hostd differientiates between these 2 values and if it notices
it changes will reject modifications when the VM is powered on,
even though our intent was not to modify the content.

This change uses *string value to distinguish all the states.
Clients that care about this value will have to do similar changes
as I made to the tests.

BREAKING: Change backingObjectId from string to *string
Signed-off-by: Nathan Prziborowski <prziborowski@gmail.com>

Author: prziborowski

object/virtual_device_list_test.go

@@ -233,7 +233,7 @@ var devices = VirtualDeviceList([]types.BaseVirtualDevice{
 					VirtualDeviceBackingInfo: types.VirtualDeviceBackingInfo{},
 					FileName:                 "[datastore1] foo.iso",
 					Datastore:                &types.ManagedObjectReference{Type: "Datastore", Value: "53fe43cc-75dc5110-3643-000c2918dc41"},
-					BackingObjectId:          "",
+					BackingObjectId:          types.New(""),
 				},
 			},
 			Connectable: &types.VirtualDeviceConnectInfo{
@@ -262,7 +262,7 @@ var devices = VirtualDeviceList([]types.BaseVirtualDevice{
 					VirtualDeviceBackingInfo: types.VirtualDeviceBackingInfo{},
 					FileName:                 "[datastore1] bar/bar.vmdk",
 					Datastore:                &types.ManagedObjectReference{Type: "Datastore", Value: "53fe43cc-75dc5110-3643-000c2918dc41"},
-					BackingObjectId:          "3-3000-0",
+					BackingObjectId:          types.New("3-3000-0"),
 				},
 				DiskMode:        "persistent",
 				Split:           types.NewBool(false),
@@ -277,7 +277,7 @@ var devices = VirtualDeviceList([]types.BaseVirtualDevice{
 						VirtualDeviceBackingInfo: types.VirtualDeviceBackingInfo{},
 						FileName:                 "[datastore1] ttylinux.vmdk",
 						Datastore:                &types.ManagedObjectReference{Type: "Datastore", Value: "53fe43cc-75dc5110-3643-000c2918dc41"},
-						BackingObjectId:          "3-3000-1",
+						BackingObjectId:          types.New("3-3000-1"),
 					},
 					DiskMode:        "persistent",
 					Split:           types.NewBool(false),
@@ -335,7 +335,7 @@ var devices = VirtualDeviceList([]types.BaseVirtualDevice{
 					VirtualDeviceBackingInfo: types.VirtualDeviceBackingInfo{},
 					FileName:                 "[datastore1] bar/disk-201-0.vmdk",
 					Datastore:                &types.ManagedObjectReference{Type: "Datastore", Value: "53fe43cc-75dc5110-3643-000c2918dc41"},
-					BackingObjectId:          "3-3002-0",
+					BackingObjectId:          types.New("3-3002-0"),
 				},
 				DiskMode:        "persistent",
 				Split:           types.NewBool(false),

vim25/types/json_test.go

@@ -611,7 +611,7 @@ var vmInfoObjForTests = VirtualMachineConfigInfo{
 					},
 					Backing: &VirtualDiskFlatVer2BackingInfo{
 						VirtualDeviceFileBackingInfo: VirtualDeviceFileBackingInfo{
-							BackingObjectId: "1",
+							BackingObjectId: New("1"),
 							FileName:        "[datastore1] test/test.vmdk",
 							Datastore: &ManagedObjectReference{
 								Type:  "Datastore",

vim25/types/types.go

@@ -86215,7 +86215,7 @@ type VirtualDeviceFileBackingInfo struct {
 	// Backing object's durable and unmutable identifier.
 	//
 	// Each backing object has a unique identifier which is not settable.
-	BackingObjectId string `xml:"backingObjectId,omitempty" json:"backingObjectId,omitempty"`
+	BackingObjectId *string `xml:"backingObjectId,omitempty" json:"backingObjectId,omitempty"`
 }
 
 func init() {