OpenStackVersion: ensure there is only one

Jira: OSPRH-6874

Author: dprince

apis/core/v1beta1/openstackversion_webhook.go

@@ -17,18 +17,24 @@ limitations under the License.
 package v1beta1
 
 import (
+	"context"
+
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 
 	"github.com/openstack-k8s-operators/lib-common/modules/common/util"
 	"k8s.io/apimachinery/pkg/runtime"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	goClient "sigs.k8s.io/controller-runtime/pkg/client"
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 )
 
+var versionWebhookClient goClient.Client
+
 // OpenStackVersionDefaults -
 type OpenStackVersionDefaults struct {
 	availableVersion string
@@ -47,13 +53,16 @@ func SetupOpenStackVersionDefaults(defaults OpenStackVersionDefaults) {
 
 // SetupWebhookWithManager - register OpenStackVersion with the controller manager
 func (r *OpenStackVersion) SetupWebhookWithManager(mgr ctrl.Manager) error {
+
+	if versionWebhookClient == nil {
+		versionWebhookClient = mgr.GetClient()
+	}
+
 	return ctrl.NewWebhookManagedBy(mgr).
 		For(r).
 		Complete()
 }
 
-// TODO(user): EDIT THIS FILE!  THIS IS SCAFFOLDING FOR YOU TO OWN!
-
 //+kubebuilder:webhook:path=/mutate-core-openstack-org-v1beta1-openstackversion,mutating=true,failurePolicy=fail,sideEffects=None,groups=core.openstack.org,resources=openstackversions,verbs=create;update,versions=v1beta1,name=mopenstackversion.kb.io,admissionReviewVersions=v1
 
 var _ webhook.Defaulter = &OpenStackVersion{}
@@ -91,6 +100,43 @@ func (r *OpenStackVersion) ValidateCreate() (admission.Warnings, error) {
 		)
 	}
 
+	versionList := &OpenStackVersionList{}
+
+	listOpts := []client.ListOption{
+		client.InNamespace(r.Namespace),
+	}
+
+	if err := versionWebhookClient.List(context.TODO(), versionList, listOpts...); err != nil {
+
+		return nil, apierrors.NewForbidden(
+			schema.GroupResource{
+				Group:    GroupVersion.WithKind("OpenStackVersion").Group,
+				Resource: GroupVersion.WithKind("OpenStackVersion").Kind,
+			}, r.GetName(), &field.Error{
+				Type:     field.ErrorTypeForbidden,
+				Field:    "",
+				BadValue: r.Spec.TargetVersion,
+				Detail:   err.Error(),
+			},
+		)
+
+	}
+
+	if len(versionList.Items) >= 1 {
+
+		return nil, apierrors.NewForbidden(
+			schema.GroupResource{
+				Group:    GroupVersion.WithKind("OpenStackVersion").Group,
+				Resource: GroupVersion.WithKind("OpenStackVersion").Kind,
+			}, r.GetName(), &field.Error{
+				Type:     field.ErrorTypeForbidden,
+				Field:    "",
+				BadValue: r.Spec.TargetVersion,
+				Detail:   "Only one OpenStackVersion instance is supported at this time.",
+			},
+		)
+	}
+
 	return nil, nil
 }
 

tests/functional/openstackversion_controller_test.go

@@ -52,6 +52,18 @@ var _ = Describe("OpenStackOperator controller", func() {
 				names.OpenStackVersionName,
 			)
 		})
+
+		It("should fail to create more than one OpenStackVersion", func() {
+
+			instance := &corev1.OpenStackVersion{}
+			instance.ObjectMeta.Namespace = names.Namespace
+			instance.Name = "foo"
+			Eventually(func(g Gomega) {
+				g.Expect(k8sClient.Create(ctx, instance)).Should(Not(Succeed()))
+			}, timeout, interval).Should(Succeed())
+
+		})
+
 		It("should initialize container images", func() {
 			Eventually(func(g Gomega) {