chore: minor refactoring

       - typo in autoscaling docs
       - drop the Decoder field in md, ms struct in webhook alias
       - change the decoder field to be set internally

docs/book/src/tasks/automated-machine-management/autoscaling.md

@@ -23,6 +23,6 @@ The defaulting logic is as follows:
   * if it's a new MachineDeployment or MachineSet, use min size
   * if the replicas field of the old MachineDeployment or MachineSet is < min size, use min size
   * if the replicas field of the old MachineDeployment or MachineSet is > max size, use max size
-  * if the replicas field of the old MachineDeployment or MachineSet is in the (min size, max size) range, keep the value from the oldMD and oldMS
+  * if the replicas field of the old MachineDeployment or MachineSet is in the (min size, max size) range, keep the value from the oldMD or oldMS
 * otherwise, use 1
 </aside>

internal/controllers/topology/cluster/reconcile_state_test.go

@@ -3241,9 +3241,8 @@ func newFakeMachineDeploymentTopologyState(name string, infrastructureMachineTem
 
 	scheme := runtime.NewScheme()
 	_ = clusterv1.AddToScheme(scheme)
-	if err := (&webhooks.MachineDeployment{
-		Decoder: admission.NewDecoder(scheme),
-	}).Default(admission.NewContextWithRequest(ctx, admission.Request{}), mdState.Object); err != nil {
+	if err := (&webhooks.MachineDeployment{}).
+		Default(admission.NewContextWithRequest(ctx, admission.Request{}), mdState.Object); err != nil {
 		panic(err)
 	}
 	return mdState

internal/webhooks/machinedeployment.go

@@ -42,8 +42,8 @@ import (
 )
 
 func (webhook *MachineDeployment) SetupWebhookWithManager(mgr ctrl.Manager) error {
-	if webhook.Decoder == nil {
-		webhook.Decoder = admission.NewDecoder(mgr.GetScheme())
+	if webhook.decoder == nil {
+		webhook.decoder = admission.NewDecoder(mgr.GetScheme())
 	}
 
 	return ctrl.NewWebhookManagedBy(mgr).
@@ -58,7 +58,7 @@ func (webhook *MachineDeployment) SetupWebhookWithManager(mgr ctrl.Manager) erro
 
 // MachineDeployment implements a validation and defaulting webhook for MachineDeployment.
 type MachineDeployment struct {
-	Decoder *admission.Decoder
+	decoder *admission.Decoder
 }
 
 var _ webhook.CustomDefaulter = &MachineDeployment{}
@@ -83,7 +83,7 @@ func (webhook *MachineDeployment) Default(ctx context.Context, obj runtime.Objec
 	var oldMD *clusterv1.MachineDeployment
 	if req.Operation == v1.Update {
 		oldMD = &clusterv1.MachineDeployment{}
-		if err := webhook.Decoder.DecodeRaw(req.OldObject, oldMD); err != nil {
+		if err := webhook.decoder.DecodeRaw(req.OldObject, oldMD); err != nil {
 			return errors.Wrapf(err, "failed to decode oldObject to MachineDeployment")
 		}
 	}

internal/webhooks/machinedeployment_test.go

@@ -52,7 +52,7 @@ func TestMachineDeploymentDefault(t *testing.T) {
 	scheme := runtime.NewScheme()
 	g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 	webhook := &MachineDeployment{
-		Decoder: admission.NewDecoder(scheme),
+		decoder: admission.NewDecoder(scheme),
 	}
 
 	reqCtx := admission.NewContextWithRequest(ctx, admission.Request{
@@ -403,7 +403,7 @@ func TestMachineDeploymentValidation(t *testing.T) {
 			scheme := runtime.NewScheme()
 			g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 			webhook := MachineDeployment{
-				Decoder: admission.NewDecoder(scheme),
+				decoder: admission.NewDecoder(scheme),
 			}
 
 			if tt.expectErr {
@@ -475,7 +475,7 @@ func TestMachineDeploymentVersionValidation(t *testing.T) {
 			scheme := runtime.NewScheme()
 			g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 			webhook := MachineDeployment{
-				Decoder: admission.NewDecoder(scheme),
+				decoder: admission.NewDecoder(scheme),
 			}
 
 			if tt.expectErr {
@@ -537,7 +537,7 @@ func TestMachineDeploymentClusterNameImmutable(t *testing.T) {
 			scheme := runtime.NewScheme()
 			g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 			webhook := MachineDeployment{
-				Decoder: admission.NewDecoder(scheme),
+				decoder: admission.NewDecoder(scheme),
 			}
 
 			warnings, err := webhook.ValidateUpdate(ctx, oldMD, newMD)
@@ -589,7 +589,7 @@ func TestMachineDeploymentTemplateMetadataValidation(t *testing.T) {
 			scheme := runtime.NewScheme()
 			g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 			webhook := MachineDeployment{
-				Decoder: admission.NewDecoder(scheme),
+				decoder: admission.NewDecoder(scheme),
 			}
 
 			if tt.expectErr {

internal/webhooks/machineset.go

@@ -43,8 +43,8 @@ import (
 )
 
 func (webhook *MachineSet) SetupWebhookWithManager(mgr ctrl.Manager) error {
-	if webhook.Decoder == nil {
-		webhook.Decoder = admission.NewDecoder(mgr.GetScheme())
+	if webhook.decoder == nil {
+		webhook.decoder = admission.NewDecoder(mgr.GetScheme())
 	}
 
 	return ctrl.NewWebhookManagedBy(mgr).
@@ -59,7 +59,7 @@ func (webhook *MachineSet) SetupWebhookWithManager(mgr ctrl.Manager) error {
 
 // MachineSet implements a validation and defaulting webhook for MachineSet.
 type MachineSet struct {
-	Decoder *admission.Decoder
+	decoder *admission.Decoder
 }
 
 var _ webhook.CustomDefaulter = &MachineSet{}
@@ -85,7 +85,7 @@ func (webhook *MachineSet) Default(ctx context.Context, obj runtime.Object) erro
 	var oldMS *clusterv1.MachineSet
 	if req.Operation == v1.Update {
 		oldMS = &clusterv1.MachineSet{}
-		if err := webhook.Decoder.DecodeRaw(req.OldObject, oldMS); err != nil {
+		if err := webhook.decoder.DecodeRaw(req.OldObject, oldMS); err != nil {
 			return errors.Wrapf(err, "failed to decode oldObject to MachineSet")
 		}
 	}

internal/webhooks/machineset_test.go

@@ -49,7 +49,7 @@ func TestMachineSetDefault(t *testing.T) {
 	scheme := runtime.NewScheme()
 	g.Expect(clusterv1.AddToScheme(scheme)).To(Succeed())
 	webhook := &MachineSet{
-		Decoder: admission.NewDecoder(scheme),
+		decoder: admission.NewDecoder(scheme),
 	}
 
 	reqCtx := admission.NewContextWithRequest(ctx, admission.Request{})

webhooks/alias.go

@@ -17,11 +17,9 @@ limitations under the License.
 package webhooks
 
 import (
+	"sigs.k8s.io/cluster-api/internal/webhooks"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
-	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
-
-	"sigs.k8s.io/cluster-api/internal/webhooks"
 )
 
 // Cluster implements a validating and defaulting webhook for Cluster.
@@ -57,27 +55,19 @@ func (webhook *Machine) SetupWebhookWithManager(mgr ctrl.Manager) error {
 }
 
 // MachineDeployment implements a validating and defaulting webhook for MachineDeployment.
-type MachineDeployment struct {
-	Decoder *admission.Decoder
-}
+type MachineDeployment struct{}
 
 // SetupWebhookWithManager sets up MachineDeployment webhooks.
 func (webhook *MachineDeployment) SetupWebhookWithManager(mgr ctrl.Manager) error {
-	return (&webhooks.MachineDeployment{
-		Decoder: webhook.Decoder,
-	}).SetupWebhookWithManager(mgr)
+	return (&webhooks.MachineDeployment{}).SetupWebhookWithManager(mgr)
 }
 
 // MachineSet implements a validating and defaulting webhook for MachineSet.
-type MachineSet struct {
-	Decoder *admission.Decoder
-}
+type MachineSet struct{}
 
 // SetupWebhookWithManager sets up MachineSet webhooks.
 func (webhook *MachineSet) SetupWebhookWithManager(mgr ctrl.Manager) error {
-	return (&webhooks.MachineSet{
-		Decoder: webhook.Decoder,
-	}).SetupWebhookWithManager(mgr)
+	return (&webhooks.MachineSet{}).SetupWebhookWithManager(mgr)
 }
 
 // MachineHealthCheck implements a validating and defaulting webhook for MachineHealthCheck.