🐛 Fix a Machine -> KubeadmConfig mapping bug

controllers/kubeadmconfig_controller.go

@@ -73,7 +73,7 @@ func (r *KubeadmConfigReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Watches(
 			&source.Kind{Type: &clusterv1.Machine{}},
 			&handler.EnqueueRequestsFromMapFunc{
-				ToRequests: util.MachineToInfrastructureMapFunc(bootstrapv1.GroupVersion.WithKind("KubeadmConfig")),
+				ToRequests: handler.ToRequestsFunc(r.MachineToBootstrapMapFunc),
 			},
 		).
 		Watches(
@@ -136,7 +136,6 @@ func (r *KubeadmConfigReconciler) Reconcile(req ctrl.Request) (_ ctrl.Result, re
 			log.Info("Cluster does not exist yet , waiting until it is created")
 			return ctrl.Result{}, nil
 		}
-
 		log.Error(err, "could not get cluster by machine metadata")
 		return ctrl.Result{}, err
 	}
@@ -400,6 +399,22 @@ func (r *KubeadmConfigReconciler) ClusterToKubeadmConfigs(o handler.MapObject) [
 	return result
 }
 
+// MachineToBootstrapMapFunc is a handler.ToRequestsFunc to be used to enqeue
+// request for reconciliation of KubeadmConfig.
+func (r *KubeadmConfigReconciler) MachineToBootstrapMapFunc(o handler.MapObject) []ctrl.Request {
+	result := []ctrl.Request{}
+
+	m, ok := o.Object.(*clusterv1.Machine)
+	if !ok {
+		return nil
+	}
+	if m.Spec.Bootstrap.ConfigRef != nil && m.Spec.Bootstrap.ConfigRef.GroupVersionKind() == bootstrapv1.GroupVersion.WithKind("KubeadmConfig") {
+		name := client.ObjectKey{Namespace: m.Namespace, Name: m.Spec.Bootstrap.ConfigRef.Name}
+		result = append(result, ctrl.Request{NamespacedName: name})
+	}
+	return result
+}
+
 // reconcileDiscovery ensures that config.JoinConfiguration.Discovery is properly set for the joining node.
 // The implementation func respect user provided discovery configurations, but in case some of them are missing, a valid BootstrapToken object
 // is automatically injected into config.JoinConfiguration.Discovery.

controllers/kubeadmconfig_controller_test.go

@@ -56,6 +56,46 @@ func setupScheme() *runtime.Scheme {
 	return scheme
 }
 
+// MachineToBootstrapMapFunc return kubeadm bootstrap configref name when configref exists
+func TestKubeadmConfigReconciler_MachineToBootstrapMapFuncReturn(t *testing.T) {
+	cluster := newCluster("my-cluster")
+	objs := []runtime.Object{cluster}
+	machineObjs := []runtime.Object{}
+	var expectedConfigName string
+	for i := 0; i < 3; i++ {
+		m := newMachine(cluster, fmt.Sprintf("my-machine-%d", i))
+		configName := fmt.Sprintf("my-config-%d", i)
+		if i == 1 {
+			c := newKubeadmConfig(m, configName)
+			objs = append(objs, m, c)
+			expectedConfigName = configName
+		} else {
+			objs = append(objs, m)
+		}
+		machineObjs = append(machineObjs, m)
+	}
+	fakeClient := fake.NewFakeClientWithScheme(setupScheme(), objs...)
+	reconciler := &KubeadmConfigReconciler{
+		Log:    log.Log,
+		Client: fakeClient,
+	}
+	for i := 0; i < 3; i++ {
+		o := handler.MapObject{
+			Object: machineObjs[i],
+		}
+		configs := reconciler.MachineToBootstrapMapFunc(o)
+		if i == 1 {
+			if configs[0].Name != expectedConfigName {
+				t.Fatalf("unexpected config name: %s", configs[0].Name)
+			}
+		} else {
+			if configs[0].Name != "" {
+				t.Fatalf("unexpected config name: %s", configs[0].Name)
+			}
+		}
+	}
+}
+
 // Reconcile returns early if the kubeadm config is ready because it should never re-generate bootstrap data.
 func TestKubeadmConfigReconciler_Reconcile_ReturnEarlyIfKubeadmConfigIsReady(t *testing.T) {
 	config := newKubeadmConfig(nil, "cfg")