test: add Flatcar e2e test

Signed-off-by: Mathieu Tortuyaux <mtortuyaux@microsoft.com>

Author: tormath1

test/e2e/config/gcp-ci.yaml

@@ -86,6 +86,10 @@ variables:
   KUBERNETES_VERSION_UPGRADE_TO: "${KUBERNETES_VERSION_UPGRADE_TO:-v1.30.5}"
   KUBERNETES_VERSION_UPGRADE_FROM: "${KUBERNETES_VERSION_UPGRADE_FROM:-v1.29.5}"
   EXP_CLUSTER_RESOURCE_SET: "true"
+  # Required for Ignition based images (e.g Flatcar)
+  EXP_KUBEADM_BOOTSTRAP_FORMAT_IGNITION: "true"
+  # TODO: Set this based on latest available image
+  FLATCAR_IMAGE_ID: "projects/kinvolk-public/global/images/flatcar-stable-4081-2-0"
   CLUSTER_TOPOLOGY: "true"
   # Cluster Addons
   CNI: "${PWD}/test/e2e/data/cni/calico/calico.yaml"

test/e2e/e2e_test.go

@@ -206,4 +206,50 @@ var _ = Describe("Workload cluster creation", func() {
 			}, result)
 		})
 	})
+
+	Context("Creating a single Flatcar control-plane cluster", func() {
+		It("Should create a cluster with 1 Flatcar worker node and can be scaled", func() {
+			By("Initializes with 1 Flatcar worker node")
+			clusterctl.ApplyClusterTemplateAndWait(ctx, clusterctl.ApplyClusterTemplateAndWaitInput{
+				ClusterProxy: bootstrapClusterProxy,
+				ConfigCluster: clusterctl.ConfigClusterInput{
+					LogFolder:                clusterctlLogFolder,
+					ClusterctlConfigPath:     clusterctlConfigPath,
+					KubeconfigPath:           bootstrapClusterProxy.GetKubeconfigPath(),
+					InfrastructureProvider:   clusterctl.DefaultInfrastructureProvider,
+					Flavor:                   "flatcar",
+					Namespace:                namespace.Name,
+					ClusterName:              clusterName,
+					KubernetesVersion:        e2eConfig.GetVariable(KubernetesVersion),
+					ControlPlaneMachineCount: ptr.To[int64](1),
+					WorkerMachineCount:       ptr.To[int64](1),
+					ClusterctlVariables:      map[string]string{"IMAGE_ID": e2eConfig.GetVariable(FlatcarImageID)},
+				},
+				WaitForClusterIntervals:      e2eConfig.GetIntervals(specName, "wait-cluster"),
+				WaitForControlPlaneIntervals: e2eConfig.GetIntervals(specName, "wait-control-plane"),
+				WaitForMachineDeployments:    e2eConfig.GetIntervals(specName, "wait-worker-nodes"),
+			}, result)
+
+			By("Scaling Flatcar worker node to 3")
+			clusterctl.ApplyClusterTemplateAndWait(ctx, clusterctl.ApplyClusterTemplateAndWaitInput{
+				ClusterProxy: bootstrapClusterProxy,
+				ConfigCluster: clusterctl.ConfigClusterInput{
+					LogFolder:                clusterctlLogFolder,
+					ClusterctlConfigPath:     clusterctlConfigPath,
+					KubeconfigPath:           bootstrapClusterProxy.GetKubeconfigPath(),
+					InfrastructureProvider:   clusterctl.DefaultInfrastructureProvider,
+					Flavor:                   "flatcar",
+					Namespace:                namespace.Name,
+					ClusterName:              clusterName,
+					KubernetesVersion:        e2eConfig.GetVariable(KubernetesVersion),
+					ControlPlaneMachineCount: ptr.To[int64](1),
+					WorkerMachineCount:       ptr.To[int64](3),
+					ClusterctlVariables:      map[string]string{"IMAGE_ID": e2eConfig.GetVariable(FlatcarImageID)},
+				},
+				WaitForClusterIntervals:      e2eConfig.GetIntervals(specName, "wait-cluster"),
+				WaitForControlPlaneIntervals: e2eConfig.GetIntervals(specName, "wait-control-plane"),
+				WaitForMachineDeployments:    e2eConfig.GetIntervals(specName, "wait-worker-nodes"),
+			}, result)
+		})
+	})
 })

test/e2e/suite_test.go

@@ -43,6 +43,7 @@ import (
 )
 
 const (
+	FlatcarImageID              = "FLATCAR_IMAGE_ID"
 	KubernetesVersion           = "KUBERNETES_VERSION"
 	KubernetesVersionManagement = "KUBERNETES_VERSION_MANAGEMENT"