[fix] Make ID the source of truth for vpc and subnet names

internal/controller/linodevpc_controller_helpers.go

@@ -44,9 +44,8 @@ func reconcileVPC(ctx context.Context, vpcScope *scope.VPCScope, logger logr.Log
 
 	createConfig.Label = vpcScope.LinodeVPC.Name
 	listFilter := util.Filter{
-		ID:    vpcScope.LinodeVPC.Spec.VPCID,
-		Label: createConfig.Label,
-		Tags:  nil,
+		ID:   vpcScope.LinodeVPC.Spec.VPCID,
+		Tags: nil,
 	}
 	filter, err := listFilter.String()
 	if err != nil {
@@ -78,23 +77,35 @@ func reconcileVPC(ctx context.Context, vpcScope *scope.VPCScope, logger logr.Log
 func reconcileExistingVPC(ctx context.Context, vpcScope *scope.VPCScope, vpc *linodego.VPC) error {
 	setVPCFields(&vpcScope.LinodeVPC.Spec, vpc)
 
-	// build a map of existing subnets to easily check for existence
-	existingSubnets := make(map[string]int, len(vpc.Subnets))
-	existingSubnetsIPv6 := make(map[string][]linodego.VPCIPv6Range, len(vpc.Subnets))
+	// Build a map of VPC subnets by both label and ID. We check for
+	// the subnet ID but fallback to the label because the ID is not guaranteed
+	// to be set until we've processed the subnet at least once.
+	type SubnetConfig struct {
+		ID    int
+		Label string
+		IPv6  []linodego.VPCIPv6Range
+	}
+	subnetsByLabel := make(map[string]SubnetConfig, len(vpc.Subnets))
+	subnetsById := make(map[int]SubnetConfig, len(vpc.Subnets))
 	for _, subnet := range vpc.Subnets {
-		existingSubnets[subnet.Label] = subnet.ID
-		existingSubnetsIPv6[subnet.Label] = subnet.IPv6
+		config := SubnetConfig{subnet.ID, subnet.Label, subnet.IPv6}
+		subnetsByLabel[subnet.Label], subnetsById[subnet.ID] = config, config
 	}
 
 	// adopt or create subnets
 	for idx, subnet := range vpcScope.LinodeVPC.Spec.Subnets {
 		if subnet.SubnetID != 0 {
-			continue
-		}
-		if id, ok := existingSubnets[subnet.Label]; ok {
-			vpcScope.LinodeVPC.Spec.Subnets[idx].SubnetID = id
-			vpcScope.LinodeVPC.Spec.Subnets[idx].IPv6 = existingSubnetsIPv6[subnet.Label]
+			if config, ok := subnetsById[subnet.SubnetID]; ok {
+				vpcScope.LinodeVPC.Spec.Subnets[idx].Label = config.Label
+				vpcScope.LinodeVPC.Spec.Subnets[idx].IPv6 = config.IPv6
+			}
+		} else if config, ok := subnetsByLabel[subnet.Label]; ok {
+			// Handle subnets that exist in the Linode API but have not had their
+			// ID set on the LinodeVPC yet.
+			vpcScope.LinodeVPC.Spec.Subnets[idx].SubnetID = config.ID
+			vpcScope.LinodeVPC.Spec.Subnets[idx].IPv6 = config.IPv6
 		} else {
+			// Handle subnets that we need to create in the Linode API.
 			ipv6 := []linodego.VPCSubnetCreateOptionsIPv6{}
 			for _, ipv6Range := range subnet.IPv6Range {
 				ipv6 = append(ipv6, linodego.VPCSubnetCreateOptionsIPv6{

internal/controller/linodevpc_controller_test.go

@@ -510,3 +510,78 @@ var _ = Describe("adopt existing VPC", Label("vpc", "lifecycle"), func() {
 		),
 	)
 })
+
+var _ = Describe("name changing VPC", Label("vpc", "lifecycle"), func() {
+	suite := NewControllerSuite(GinkgoT(), mock.MockLinodeClient{})
+
+	var reconciler LinodeVPCReconciler
+	var vpcScope scope.VPCScope
+	var linodeVPC infrav1alpha2.LinodeVPC
+
+	suite.BeforeEach(func(ctx context.Context, mck Mock) {
+		vpcScope.Client = k8sClient
+		linodeVPC = infrav1alpha2.LinodeVPC{
+			ObjectMeta: metav1.ObjectMeta{
+				GenerateName: "changing-vpc-",
+				Namespace:    "default",
+			},
+			Spec: infrav1alpha2.LinodeVPCSpec{
+				Region: "us-east",
+				Subnets: []infrav1alpha2.VPCSubnetCreateOptions{
+					{Label: "changing-subnet", SubnetID: 1, IPv4: "10.0.0.0/8"},
+				},
+			},
+		}
+		Expect(k8sClient.Create(ctx, &linodeVPC)).To(Succeed())
+
+		vpcScope.LinodeClient = mck.LinodeClient
+
+		reconciler = LinodeVPCReconciler{
+			Recorder: mck.Recorder(),
+		}
+
+		Expect(k8sClient.Get(ctx, client.ObjectKeyFromObject(&linodeVPC), &linodeVPC)).To(Succeed())
+		vpcScope.LinodeVPC = &linodeVPC
+
+		patchHelper, err := patch.NewHelper(&linodeVPC, k8sClient)
+		Expect(err).NotTo(HaveOccurred())
+		vpcScope.PatchHelper = patchHelper
+	})
+
+	AfterEach(func(ctx SpecContext) {
+		err := k8sClient.Delete(ctx, &linodeVPC)
+		if err != nil {
+			Expect(apierrors.IsNotFound(err)).To(BeTrue())
+		}
+	})
+
+	suite.Run(
+		Path(
+			Call("get existing VPC and adapt to name changes", func(ctx context.Context, mck Mock) {
+				mck.LinodeClient.EXPECT().ListVPCs(ctx, gomock.Any()).Return([]linodego.VPC{
+					{
+						ID:     1,
+						Label:  "changed-vpc-",
+						Region: "us-east",
+						Subnets: []linodego.VPCSubnet{
+							{
+								ID:    1,
+								Label: "changed-subnet-",
+								IPv4:  "10.0.0.0/8",
+							},
+						},
+					},
+				}, nil)
+			}),
+			Result("reconcile VPC with changed name and create success", func(ctx context.Context, mck Mock) {
+				_, err := reconciler.reconcile(ctx, mck.Logger(), &vpcScope)
+				Expect(err).NotTo(HaveOccurred())
+
+				Expect(k8sClient.Get(ctx, client.ObjectKeyFromObject(&linodeVPC), &linodeVPC)).To(Succeed())
+				Expect(len(linodeVPC.Spec.Subnets)).To(Equal(1))
+				Expect(linodeVPC.Spec.Subnets[0].SubnetID).To(Equal(1))
+				Expect(linodeVPC.Spec.Subnets[0].Label).To(Equal("changed-subnet-"))
+			}),
+		),
+	)
+})