1. cluster-template-ci-dual-stack-with-ipv6primary.yaml

  Located at: /Users/bbarbach/dev/k8s-cluster-api-provider-gcp/test/e2e/data/infrastructure-gcp/

  This template creates a DualStack cluster with IPv6 as the primary address:
  - stackType: "DualStack"
  - addressPreferencePolicy: "IPv6Primary"

  2. dual_stack_test.go

  Located at: /Users/bbarbach/dev/k8s-cluster-api-provider-gcp/test/e2e/

  This comprehensive test file includes three test contexts:

  Test 1: DualStack with IPv4Primary (Default)

  - Uses flavor: ci-with-dual-stack
  - Verifies StackType is DualStack
  - Verifies AddressPreferencePolicy defaults to IPv4Primary
  - Validates both IPv4 and IPv6 addresses are allocated
  - Confirms control plane endpoint uses IPv4 address
  - Checks both IPv4 and IPv6 forwarding rules exist

  Test 2: DualStack with IPv6Primary

  - Uses flavor: ci-dual-stack-with-ipv6primary
  - Verifies StackType is DualStack
  - Verifies AddressPreferencePolicy is IPv6Primary
  - Validates both IPv4 and IPv6 addresses are allocated
  - Confirms control plane endpoint uses IPv6 address (key difference)
  - Checks both IPv4 and IPv6 forwarding rules exist

  Test 3: IPv4Only (Default Behavior)

  - Uses default flavor
  - Verifies StackType is IPv4Only or empty (defaults to IPv4Only)
  - Validates only IPv4 addresses are allocated
  - Confirms no IPv6 addresses or forwarding rules exist
  - Verifies control plane endpoint uses IPv4 address

  3. Updated gcp-ci.yaml

  Added the new template to the e2e configuration so it can be used in tests.

  4. Moved Dual stack tests from e2e_test.go to dual_stack_test.go

Author: barbacbd

test/e2e/config/gcp-ci.yaml

@@ -78,6 +78,7 @@ providers:
       - sourcePath: "${PWD}/test/e2e/data/infrastructure-gcp/cluster-template-ci-with-internal-lb.yaml"
       - sourcePath: "${PWD}/test/e2e/data/infrastructure-gcp/withclusterclass/cluster-template-ci-gke-autopilot-topology.yaml"
       - sourcePath: "${PWD}/test/e2e/data/infrastructure-gcp/cluster-template-ci-with-dual-stack.yaml"
+      - sourcePath: "${PWD}/test/e2e/data/infrastructure-gcp/cluster-template-ci-dual-stack-with-ipv6primary.yaml"
 
 variables:
   KUBERNETES_VERSION: "v1.33.2"

test/e2e/data/infrastructure-gcp/cluster-template-ci-dual-stack-with-ipv6primary.yaml

@@ -0,0 +1,169 @@
+---
+apiVersion: cluster.x-k8s.io/v1beta1
+kind: Cluster
+metadata:
+  name: "${CLUSTER_NAME}"
+  labels:
+    cni: "${CLUSTER_NAME}-crs-cni"
+    ccm: "${CLUSTER_NAME}-crs-ccm"
+spec:
+  clusterNetwork:
+    pods:
+      cidrBlocks: ["192.168.0.0/16"]
+  infrastructureRef:
+    apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+    kind: GCPCluster
+    name: "${CLUSTER_NAME}"
+  controlPlaneRef:
+    kind: KubeadmControlPlane
+    apiVersion: controlplane.cluster.x-k8s.io/v1beta1
+    name: "${CLUSTER_NAME}-control-plane"
+---
+apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+kind: GCPCluster
+metadata:
+  name: "${CLUSTER_NAME}"
+spec:
+  project: "${GCP_PROJECT}"
+  region: "${GCP_REGION}"
+  network:
+    name: "${GCP_NETWORK_NAME}"
+    internalIpv6PrefixLength: 64
+    stackType: "DualStack"
+    addressPreferencePolicy: "IPv6Primary"
+---
+apiVersion: controlplane.cluster.x-k8s.io/v1beta1
+kind: KubeadmControlPlane
+metadata:
+  name: "${CLUSTER_NAME}-control-plane"
+spec:
+  replicas: ${CONTROL_PLANE_MACHINE_COUNT}
+  machineTemplate:
+    infrastructureRef:
+      kind: GCPMachineTemplate
+      apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+      name: "${CLUSTER_NAME}-control-plane"
+  kubeadmConfigSpec:
+    initConfiguration:
+      nodeRegistration:
+        name: '{{ ds.meta_data.local_hostname.split(".")[0] }}'
+        kubeletExtraArgs:
+          cloud-provider: external
+    clusterConfiguration:
+      apiServer:
+        timeoutForControlPlane: 20m
+      controllerManager:
+        extraArgs:
+          cloud-provider: external
+          allocate-node-cidrs: "false"
+      kubernetesVersion: "${KUBERNETES_VERSION}"
+    files:
+      - content: |
+          [Global]
+
+          project-id = "${GCP_PROJECT}"
+          network-name = "${GCP_NETWORK_NAME}"
+          multizone = true
+        owner: root:root
+        path: /etc/kubernetes/cloud.config
+        permissions: "0744"
+    joinConfiguration:
+      nodeRegistration:
+        name: '{{ ds.meta_data.local_hostname.split(".")[0] }}'
+        kubeletExtraArgs:
+          cloud-provider: external
+  version: "${KUBERNETES_VERSION}"
+---
+apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+kind: GCPMachineTemplate
+metadata:
+  name: "${CLUSTER_NAME}-control-plane"
+spec:
+  template:
+    spec:
+      instanceType: "${GCP_CONTROL_PLANE_MACHINE_TYPE}"
+      image: "${IMAGE_ID}"
+---
+apiVersion: cluster.x-k8s.io/v1beta1
+kind: MachineDeployment
+metadata:
+  name: "${CLUSTER_NAME}-md-0"
+spec:
+  clusterName: "${CLUSTER_NAME}"
+  replicas: ${WORKER_MACHINE_COUNT}
+  selector:
+    matchLabels:
+  template:
+    spec:
+      clusterName: "${CLUSTER_NAME}"
+      version: "${KUBERNETES_VERSION}"
+      bootstrap:
+        configRef:
+          name: "${CLUSTER_NAME}-md-0"
+          apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
+          kind: KubeadmConfigTemplate
+      infrastructureRef:
+        name: "${CLUSTER_NAME}-md-0"
+        apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+        kind: GCPMachineTemplate
+---
+apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
+kind: GCPMachineTemplate
+metadata:
+  name: "${CLUSTER_NAME}-md-0"
+spec:
+  template:
+    spec:
+      instanceType: "${GCP_NODE_MACHINE_TYPE}"
+      image: "${IMAGE_ID}"
+---
+apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
+kind: KubeadmConfigTemplate
+metadata:
+  name: "${CLUSTER_NAME}-md-0"
+spec:
+  template:
+    spec:
+      joinConfiguration:
+        nodeRegistration:
+          name: '{{ ds.meta_data.local_hostname.split(".")[0] }}'
+          kubeletExtraArgs:
+            cloud-provider: external
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: "${CLUSTER_NAME}-crs-cni"
+data: ${CNI_RESOURCES}
+---
+apiVersion: addons.cluster.x-k8s.io/v1beta1
+kind: ClusterResourceSet
+metadata:
+  name: "${CLUSTER_NAME}-crs-cni"
+spec:
+  strategy: ApplyOnce
+  clusterSelector:
+    matchLabels:
+      cni: "${CLUSTER_NAME}-crs-cni"
+  resources:
+    - name: "${CLUSTER_NAME}-crs-cni"
+      kind: ConfigMap
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: "${CLUSTER_NAME}-crs-ccm"
+data: ${CCM_RESOURCES}
+---
+apiVersion: addons.cluster.x-k8s.io/v1beta1
+kind: ClusterResourceSet
+metadata:
+  name: "${CLUSTER_NAME}-crs-ccm"
+spec:
+  strategy: ApplyOnce
+  clusterSelector:
+    matchLabels:
+      ccm: "${CLUSTER_NAME}-crs-ccm"
+  resources:
+    - name: "${CLUSTER_NAME}-crs-ccm"
+      kind: ConfigMap