From e6f37eab329c2d63deef76308f649e1bc59ab030 Mon Sep 17 00:00:00 2001
From: Christian Schlotter <christian.schlotter@broadcom.com>
Date: Thu, 1 Aug 2024 15:53:34 +0200
Subject: [PATCH] test: add coverage to find issues running on the next
 kubernetes release as management cluster

---
 scripts/ci-e2e-lib.sh               | 10 ++++++++++
 test/e2e/clusterctl_upgrade_test.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/scripts/ci-e2e-lib.sh b/scripts/ci-e2e-lib.sh
index 259d88193fb0..a1aeacb2863f 100644
--- a/scripts/ci-e2e-lib.sh
+++ b/scripts/ci-e2e-lib.sh
@@ -63,6 +63,16 @@ k8s::prepareKindestImagesVariables() {
     fi
   fi
 
+  # Tests not focusing on anything and skipping [Conformance] run a clusterctl upgrade test
+  # on the latest kubernetes version as management cluster.
+  if  [[ ${GINKGO_FOCUS:-} == "" ]] && [[ ${GINKGO_SKIP} == *"Conformance"* ]]; then
+    # Note: We do this because we want to specify KUBERNETES_VERSION_LATEST_CI *only* in the e2e config.
+    if [[ -z "${KUBERNETES_VERSION_LATEST_CI:-}" ]]; then
+      KUBERNETES_VERSION_LATEST_CI=$(grep KUBERNETES_VERSION_LATEST_CI: < "$E2E_CONF_FILE" | awk -F'"' '{ print $2}')
+      echo "Defaulting KUBERNETES_VERSION_LATEST_CI to ${KUBERNETES_VERSION_LATEST_CI} to trigger image build (because env var is not set)"
+    fi
+  fi
+
   # Tests not focusing on [PR-Blocking], [K8s-Install] or [K8s-Install-ci-latest],
   # also run upgrade tests so default KUBERNETES_VERSION_UPGRADE_TO and KUBERNETES_VERSION_UPGRADE_FROM
   # to the value in the e2e config if they are not set.
diff --git a/test/e2e/clusterctl_upgrade_test.go b/test/e2e/clusterctl_upgrade_test.go
index 087864997c4b..93b5dbf1839d 100644
--- a/test/e2e/clusterctl_upgrade_test.go
+++ b/test/e2e/clusterctl_upgrade_test.go
@@ -28,6 +28,7 @@ import (
 	"k8s.io/utils/ptr"
 
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+	"sigs.k8s.io/cluster-api/test/framework/kubernetesversions"
 )
 
 var (
@@ -325,3 +326,31 @@ var _ = Describe("When testing clusterctl upgrades using ClusterClass (v1.7=>cur
 		}
 	})
 })
+
+var _ = Describe("When testing clusterctl upgrades using ClusterClass (v1.7=>current) on K8S latest ci mgmt cluster [ClusterClass]", func() {
+	// Get v1.7 latest stable release
+	version := "1.7"
+	stableRelease, err := GetStableReleaseOfMinor(ctx, version)
+	Expect(err).ToNot(HaveOccurred(), "Failed to get stable version for minor release : %s", version)
+	ClusterctlUpgradeSpec(ctx, func() ClusterctlUpgradeSpecInput {
+		initKubernetesVersion, err := kubernetesversions.ResolveVersion(ctx, e2eConfig.GetVariable("KUBERNETES_VERSION_LATEST_CI"))
+		Expect(err).ToNot(HaveOccurred())
+		return ClusterctlUpgradeSpecInput{
+			E2EConfig:                 e2eConfig,
+			ClusterctlConfigPath:      clusterctlConfigPath,
+			BootstrapClusterProxy:     bootstrapClusterProxy,
+			ArtifactFolder:            artifactFolder,
+			SkipCleanup:               skipCleanup,
+			InfrastructureProvider:    ptr.To("docker"),
+			InitWithBinary:            fmt.Sprintf(clusterctlDownloadURL, stableRelease),
+			InitWithProvidersContract: "v1beta1",
+			// Note: InitWithKubernetesVersion should be the latest of the next supported kubernetes version by the target Cluster API version.
+			// Note: WorkloadKubernetesVersion should be the highest mgmt cluster version supported by the source Cluster API version.
+			InitWithKubernetesVersion:   initKubernetesVersion,
+			WorkloadKubernetesVersion:   "v1.30.0",
+			MgmtFlavor:                  "topology",
+			WorkloadFlavor:              "topology",
+			UseKindForManagementCluster: true,
+		}
+	})
+})