Validate OpenStackMachineTemplate spec.template.spec immutability

Signed-off-by: Johannes Frey <[email protected]>

Author: Johannes Frey

api/v1alpha4/openstackmachinetemplate_webhook.go

@@ -17,7 +17,6 @@ limitations under the License.
 package v1alpha4
 
 import (
-	"errors"
 	"reflect"
 
 	"k8s.io/apimachinery/pkg/runtime"
@@ -27,6 +26,9 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 )
 
+// OpenStackMachineTemplateImmutableMsg ...
+const OpenStackMachineTemplateImmutableMsg = "OpenStackMachineTemplate spec.template.spec field is immutable. Please create a new resource instead. Ref doc: https://cluster-api.sigs.k8s.io/tasks/change-machine-template.html"
+
 func (r *OpenStackMachineTemplate) SetupWebhookWithManager(mgr manager.Manager) error {
 	return builder.WebhookManagedBy(mgr).
 		For(r).
@@ -51,9 +53,17 @@ func (r *OpenStackMachineTemplate) ValidateCreate() error {
 
 // ValidateUpdate implements webhook.Validator so a webhook will be registered for the type.
 func (r *OpenStackMachineTemplate) ValidateUpdate(old runtime.Object) error {
+	var allErrs field.ErrorList
 	oldOpenStackMachineTemplate := old.(*OpenStackMachineTemplate)
-	if !reflect.DeepEqual(r.Spec, oldOpenStackMachineTemplate.Spec) {
-		return errors.New("openstackMachineTemplateSpec is immutable")
+
+	if !reflect.DeepEqual(r.Spec.Template.Spec, oldOpenStackMachineTemplate.Spec.Template.Spec) {
+		allErrs = append(allErrs,
+			field.Invalid(field.NewPath("spec", "template", "spec"), r, OpenStackMachineTemplateImmutableMsg),
+		)
+	}
+
+	if len(allErrs) != 0 {
+		return aggregateObjErrors(r.GroupVersionKind().GroupKind(), r.Name, allErrs)
 	}
 
 	return nil

api/v1alpha4/openstackmachinetemplate_webhook_test.go

@@ -0,0 +1,100 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha4
+
+import (
+	"testing"
+
+	. "github.com/onsi/gomega"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestOpenStackMachineTemplate_ValidateUpdate(t *testing.T) {
+	g := NewWithT(t)
+
+	tests := []struct {
+		name        string
+		oldTemplate *OpenStackMachineTemplate
+		newTemplate *OpenStackMachineTemplate
+		wantErr     bool
+	}{
+		{
+			name: "OpenStackMachineTemplate with immutable spec",
+			oldTemplate: &OpenStackMachineTemplate{
+				Spec: OpenStackMachineTemplateSpec{
+					Template: OpenStackMachineTemplateResource{
+						Spec: OpenStackMachineSpec{
+							Flavor: "foo",
+							Image:  "bar",
+						},
+					},
+				},
+			},
+			newTemplate: &OpenStackMachineTemplate{
+				Spec: OpenStackMachineTemplateSpec{
+					Template: OpenStackMachineTemplateResource{
+						Spec: OpenStackMachineSpec{
+							Flavor: "foo",
+							Image:  "NewImage",
+						},
+					},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "OpenStackMachineTemplate with mutable metadata",
+			oldTemplate: &OpenStackMachineTemplate{
+				Spec: OpenStackMachineTemplateSpec{
+					Template: OpenStackMachineTemplateResource{
+						Spec: OpenStackMachineSpec{
+							Flavor: "foo",
+							Image:  "bar",
+						},
+					},
+				},
+				ObjectMeta: v1.ObjectMeta{
+					Name: "foo",
+				},
+			},
+			newTemplate: &OpenStackMachineTemplate{
+				Spec: OpenStackMachineTemplateSpec{
+					Template: OpenStackMachineTemplateResource{
+						Spec: OpenStackMachineSpec{
+							Flavor: "foo",
+							Image:  "bar",
+						},
+					},
+				},
+				ObjectMeta: v1.ObjectMeta{
+					Name: "bar",
+				},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			err := tt.newTemplate.ValidateUpdate(tt.oldTemplate)
+			if tt.wantErr {
+				g.Expect(err).To(HaveOccurred())
+			} else {
+				g.Expect(err).NotTo(HaveOccurred())
+			}
+		})
+	}
+}