fix(v1alpha1): handle empty network fields (vmware-tanzu#1391)

Fix nil pointer dereference in v1alpha1 to v1alpha5 conversion when
both NetworkName and NetworkType are empty. Move Network object
initialization inside conditional check and add test case.

Author: zhangheliu

api/test/v1alpha1/virtualmachine_conversion_test.go

@@ -1758,6 +1758,30 @@ func TestVirtualMachineConversion(t *testing.T) {
 		spokeHubSpoke(g, &spoke, &vmopv1.VirtualMachine{})
 	})
 
+	t.Run("VirtualMachine spoke-hub-spoke with empty NetworkName and NetworkType", func(t *testing.T) {
+		g := NewWithT(t)
+
+		// Test the edge case where both NetworkName and NetworkType are empty strings.
+		// This is valid in v1alpha1 and should not cause a nil pointer dereference.
+		spoke := vmopv1a1.VirtualMachine{
+			Spec: vmopv1a1.VirtualMachineSpec{
+				ClassName: "best-effort-small",
+				ImageName: "vmi-d5973af773e94c1d8",
+				NetworkInterfaces: []vmopv1a1.VirtualMachineNetworkInterface{
+					{
+						NetworkName: "",
+						NetworkType: "",
+					},
+				},
+			},
+			Status: vmopv1a1.VirtualMachineStatus{
+				Phase: vmopv1a1.Unknown,
+			},
+		}
+
+		spokeHubSpoke(g, &spoke, &vmopv1.VirtualMachine{})
+	})
+
 	t.Run("VirtualMachine spoke-hub-spoke with ExtraConfig", func(t *testing.T) {
 		g := NewWithT(t)
 

api/v1alpha1/virtualmachine_conversion.go

@@ -274,23 +274,22 @@ func convert_v1alpha1_NetworkInterface_To_v1alpha5_NetworkInterfaceSpec(
 
 	if in.NetworkName != "" || in.NetworkType != "" {
 		out.Network = &vmopv1common.PartialObjectRef{}
-	}
-
-	out.Network.Name = in.NetworkName
-
-	switch in.NetworkType {
-	case "vsphere-distributed":
-		out.Network.TypeMeta.APIVersion = "netoperator.vmware.com/v1alpha1"
-		out.Network.TypeMeta.Kind = "Network"
-	case "nsx-t":
-		out.Network.TypeMeta.APIVersion = "vmware.com/v1alpha1"
-		out.Network.TypeMeta.Kind = "VirtualNetwork"
-	case "nsx-t-subnet":
-		out.Network.TypeMeta.APIVersion = "crd.nsx.vmware.com/v1alpha1"
-		out.Network.TypeMeta.Kind = "Subnet"
-	case "nsx-t-subnetset":
-		out.Network.TypeMeta.APIVersion = "crd.nsx.vmware.com/v1alpha1"
-		out.Network.TypeMeta.Kind = "SubnetSet"
+		out.Network.Name = in.NetworkName
+
+		switch in.NetworkType {
+		case "vsphere-distributed":
+			out.Network.TypeMeta.APIVersion = "netoperator.vmware.com/v1alpha1"
+			out.Network.TypeMeta.Kind = "Network"
+		case "nsx-t":
+			out.Network.TypeMeta.APIVersion = "vmware.com/v1alpha1"
+			out.Network.TypeMeta.Kind = "VirtualNetwork"
+		case "nsx-t-subnet":
+			out.Network.TypeMeta.APIVersion = "crd.nsx.vmware.com/v1alpha1"
+			out.Network.TypeMeta.Kind = "Subnet"
+		case "nsx-t-subnetset":
+			out.Network.TypeMeta.APIVersion = "crd.nsx.vmware.com/v1alpha1"
+			out.Network.TypeMeta.Kind = "SubnetSet"
+		}
 	}
 
 	return out