neonvm-controller: implement migration webhooks (#1295)

Not much we need to check for, but it guards us from creating a
migration for the wrong VM.

Closes #719.

---------

Signed-off-by: Oleg Vasilev <[email protected]>

Author: Omrigan

neonvm/apis/neonvm/v1/virtualmachinemigration_types.go

@@ -28,6 +28,7 @@ const MigrationPort int32 = 20187
 
 // VirtualMachineMigrationSpec defines the desired state of VirtualMachineMigration
 type VirtualMachineMigrationSpec struct {
+	// +kubebuilder:validation:MinLength=1
 	VmName string `json:"vmName"`
 
 	// TODO: not implemented

neonvm/apis/neonvm/v1/virtualmachinemigration_webhook.go

@@ -17,6 +17,9 @@ limitations under the License.
 package v1
 
 import (
+	"fmt"
+	"reflect"
+
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
@@ -42,22 +45,24 @@ var _ webhook.Validator = &VirtualMachineMigration{}
 //
 // The controller wraps this logic so it can inject extra control in the webhook.
 func (r *VirtualMachineMigration) ValidateCreate() (admission.Warnings, error) {
-	// TODO: implement creation validation webhook (?)
 	return nil, nil
 }
 
 // ValidateUpdate implements webhook.Validator
 //
 // The controller wraps this logic so it can inject extra control in the webhook.
 func (r *VirtualMachineMigration) ValidateUpdate(old runtime.Object) (admission.Warnings, error) {
-	// TODO: implement update validation webhook
+	oldVMM := old.(*VirtualMachineMigration)
+	if !reflect.DeepEqual(r.Spec, oldVMM.Spec) {
+		return nil, fmt.Errorf("updating migration spec is not allowed")
+	}
 	return nil, nil
 }
 
 // ValidateDelete implements webhook.Validator
 //
 // The controller wraps this logic so it can inject extra control in the webhook.
 func (r *VirtualMachineMigration) ValidateDelete() (admission.Warnings, error) {
-	// TODO: implement deletion validation webhook (?)
+	// No validation needed - we have a finalizer that prevents deletion
 	return nil, nil
 }

neonvm/config/crd/bases/vm.neon.tech_virtualmachinemigrations.yaml

@@ -300,6 +300,7 @@ spec:
                 default: true
                 type: boolean
               vmName:
+                minLength: 1
                 type: string
             required:
             - vmName

pkg/neonvm/controllers/functests/vm_controller_test.go

@@ -149,3 +149,25 @@ var _ = Describe("VirtualMachine controller", func() {
 		})
 	})
 })
+
+var _ = Describe("VirtualMachineMigration controller", func() {
+	It("should reject invalid VirtualMachineMigration", func() {
+		ctx := context.Background()
+
+		By("Creating the custom resource for the Kind VirtualMachineMigration")
+		virtualmachinemigration := &vmv1.VirtualMachineMigration{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test-migration",
+				Namespace: "default",
+			},
+		}
+		err := k8sClient.Create(ctx, virtualmachinemigration)
+		Expect(err).To(HaveOccurred())
+		Expect(err.Error()).To(ContainSubstring("spec.vmName in body should be at least 1 chars long"))
+
+		// Now fix it
+		virtualmachinemigration.Spec.VmName = "test-vm"
+		err = k8sClient.Create(ctx, virtualmachinemigration)
+		Expect(err).To(Not(HaveOccurred()))
+	})
+})