Validate MachineSet and MachineDeployment labels (#739)

Signed-off-by: Vince Prignano <[email protected]>

cmd/clusterctl/clusterdeployer/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
         "//cmd/clusterctl/phases:go_default_library",
         "//cmd/clusterctl/providercomponents:go_default_library",
         "//pkg/apis/cluster/v1alpha1:go_default_library",
+        "//pkg/util:go_default_library",
         "//vendor/github.com/pkg/errors:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
         "//vendor/k8s.io/klog:go_default_library",

cmd/clusterctl/clusterdeployer/clusterdeployer.go

@@ -109,7 +109,7 @@ func (d *ClusterDeployer) Create(cluster *clusterv1.Cluster, machines []*cluster
 		}
 	}
 
-	klog.Info("Creating namespace %q on target cluster", cluster.Namespace)
+	klog.Infof("Creating namespace %q on target cluster", cluster.Namespace)
 	addNamespaceToTarget := func() (bool, error) {
 		err = targetClient.EnsureNamespace(cluster.Namespace)
 		if err != nil {

pkg/controller/machinedeployment/controller.go

@@ -161,6 +161,17 @@ func (r *ReconcileMachineDeployment) Reconcile(request reconcile.Request) (recon
 		return reconcile.Result{}, nil
 	}
 
+	// Make sure that label selector can match template's labels.
+	// TODO(vincepri): Move to a validation (admission) webhook when supported.
+	selector, err := metav1.LabelSelectorAsSelector(&d.Spec.Selector)
+	if err != nil {
+		return reconcile.Result{}, errors.Wrapf(err, "failed to parse MachineDeployment %q label selector", d.Name)
+	}
+
+	if !selector.Matches(labels.Set(d.Spec.Template.Labels)) {
+		return reconcile.Result{}, errors.Errorf("failed validation on MachineDeployment %q label selector, cannot match any machines ", d.Name)
+	}
+
 	msList, err := r.getMachineSetsForDeployment(d)
 	if err != nil {
 		return reconcile.Result{}, err

pkg/controller/machineset/controller.go

@@ -26,6 +26,7 @@ import (
 	"github.com/pkg/errors"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/klog"
 	clusterv1alpha1 "sigs.k8s.io/cluster-api/pkg/apis/cluster/v1alpha1"
@@ -158,6 +159,17 @@ func (r *ReconcileMachineSet) Reconcile(request reconcile.Request) (reconcile.Re
 		return reconcile.Result{}, errors.Wrap(err, "failed to list machines")
 	}
 
+	// Make sure that label selector can match template's labels.
+	// TODO(vincepri): Move to a validation (admission) webhook when supported.
+	selector, err := metav1.LabelSelectorAsSelector(&machineSet.Spec.Selector)
+	if err != nil {
+		return reconcile.Result{}, errors.Wrapf(err, "failed to parse MachineSet %q label selector", machineSet.Name)
+	}
+
+	if !selector.Matches(labels.Set(machineSet.Spec.Template.Labels)) {
+		return reconcile.Result{}, errors.Errorf("failed validation on MachineSet %q label selector, cannot match any machines ", machineSet.Name)
+	}
+
 	// Filter out irrelevant machines (deleting/mismatch labels) and claim orphaned machines.
 	filteredMachines := make([]*clusterv1alpha1.Machine, 0, len(allMachines.Items))
 	for idx := range allMachines.Items {