SKS-1573: Add DeleteMachineAnnotation to the failed CP Machine when s…

…caling down KCP after a failed rolling update (#128)

controllers/elfmachine_controller_test.go

@@ -1465,6 +1465,7 @@ var _ = Describe("ElfMachineReconciler", func() {
 				kcp.Spec.Replicas = pointer.Int32(1)
 				kcp.Status.Replicas = 2
 				kcp.Status.UpdatedReplicas = kcp.Status.Replicas
+				conditions.MarkFalse(kcp, controlplanev1.ResizedCondition, controlplanev1.ScalingDownReason, clusterv1.ConditionSeverityWarning, "")
 				host := fake.NewTowerHost()
 				elfMachine1, machine1 := fake.NewMachineObjects(elfCluster, cluster)
 				fake.ToControlPlaneMachine(machine1, kcp)

pkg/util/kcp/kcp.go

@@ -17,7 +17,9 @@ limitations under the License.
 */
 
 import (
+	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
 	controlplanev1 "sigs.k8s.io/cluster-api/controlplane/kubeadm/api/v1beta1"
+	"sigs.k8s.io/cluster-api/util/conditions"
 )
 
 // IsKCPRollingUpdateFirstMachine returns true if KCP is in rolling update and creating the first CP Machine.
@@ -41,10 +43,12 @@ func IsKCPRollingUpdateFirstMachine(kcp *controlplanev1.KubeadmControlPlane) boo
 
 // IsKCPInScalingDown returns whether KCP is in scaling down.
 //
-// When KCP is in scaling down, machines managed by KCP is greater than kcp.Spec.Replicas,
-// and these machines are up to date with the control plane's configuration.
+// When KCP is in scaling down/rolling update, KCP controller marks
+// ResizedCondition to false and ScalingDownReason as Reason.
 //
-// For more information about KCP replicas, refer to https://github.com/kubernetes-sigs/cluster-api/blob/main/controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_types.go
+// For more information about KCP ResizedCondition and ScalingDownReason, refer to https://github.com/kubernetes-sigs/cluster-api/blob/main/api/v1beta1/condition_consts.go
 func IsKCPInScalingDown(kcp *controlplanev1.KubeadmControlPlane) bool {
-	return *kcp.Spec.Replicas < kcp.Status.Replicas && kcp.Status.Replicas == kcp.Status.UpdatedReplicas
+	return conditions.IsFalse(kcp, clusterv1.ResizedCondition) &&
+		conditions.GetReason(kcp, controlplanev1.ResizedCondition) == controlplanev1.ScalingDownReason &&
+		*kcp.Spec.Replicas < kcp.Status.UpdatedReplicas
 }