⚠️ Deprecate admission.Validator and admission.Defaulter

`admission.Validator/Defaulter` require to import controller-runtime
into api packages. This is not recommended, as api packages should
themselves not have any dependencies except to other api packages in
order to make importing them easy without dependency issues and
possibility incompatibilities.

This change marks the two as deprecated. We are not going to remove them
yet to give folks some time to migrate off them.

examples/crd/pkg/resource.go

@@ -17,14 +17,8 @@ limitations under the License.
 package pkg
 
 import (
-	"fmt"
-	"time"
-
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime"
-	"sigs.k8s.io/controller-runtime/pkg/webhook"
-	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 )
 
 // ChaosPodSpec defines the desired state of ChaosPod
@@ -62,61 +56,6 @@ type ChaosPodList struct {
 	Items           []ChaosPod `json:"items"`
 }
 
-// +kubebuilder:webhook:path=/validate-chaosapps-metamagical-io-v1-chaospod,mutating=false,failurePolicy=fail,groups=chaosapps.metamagical.io,resources=chaospods,verbs=create;update,versions=v1,name=vchaospod.kb.io
-
-var _ webhook.Validator = &ChaosPod{}
-
-// ValidateCreate implements webhookutil.validator so a webhook will be registered for the type
-func (c *ChaosPod) ValidateCreate() (admission.Warnings, error) {
-	log.Info("validate create", "name", c.Name)
-
-	if c.Spec.NextStop.Before(&metav1.Time{Time: time.Now()}) {
-		return nil, fmt.Errorf(".spec.nextStop must be later than current time")
-	}
-	return nil, nil
-}
-
-// ValidateUpdate implements webhookutil.validator so a webhook will be registered for the type
-func (c *ChaosPod) ValidateUpdate(old runtime.Object) (admission.Warnings, error) {
-	log.Info("validate update", "name", c.Name)
-
-	if c.Spec.NextStop.Before(&metav1.Time{Time: time.Now()}) {
-		return nil, fmt.Errorf(".spec.nextStop must be later than current time")
-	}
-
-	oldC, ok := old.(*ChaosPod)
-	if !ok {
-		return nil, fmt.Errorf("expect old object to be a %T instead of %T", oldC, old)
-	}
-	if c.Spec.NextStop.After(oldC.Spec.NextStop.Add(time.Hour)) {
-		return nil, fmt.Errorf("it is not allowed to delay.spec.nextStop for more than 1 hour")
-	}
-	return nil, nil
-}
-
-// ValidateDelete implements webhookutil.validator so a webhook will be registered for the type
-func (c *ChaosPod) ValidateDelete() (admission.Warnings, error) {
-	log.Info("validate delete", "name", c.Name)
-
-	if c.Spec.NextStop.Before(&metav1.Time{Time: time.Now()}) {
-		return nil, fmt.Errorf(".spec.nextStop must be later than current time")
-	}
-	return nil, nil
-}
-
-// +kubebuilder:webhook:path=/mutate-chaosapps-metamagical-io-v1-chaospod,mutating=true,failurePolicy=fail,groups=chaosapps.metamagical.io,resources=chaospods,verbs=create;update,versions=v1,name=mchaospod.kb.io
-
-var _ webhook.Defaulter = &ChaosPod{}
-
-// Default implements webhookutil.defaulter so a webhook will be registered for the type
-func (c *ChaosPod) Default() {
-	log.Info("default", "name", c.Name)
-
-	if c.Spec.NextStop.Before(&metav1.Time{Time: time.Now()}) {
-		c.Spec.NextStop = metav1.Time{Time: time.Now().Add(time.Minute)}
-	}
-}
-
 func init() {
 	SchemeBuilder.Register(&ChaosPod{}, &ChaosPodList{})
 }

pkg/webhook/admission/defaulter.go

@@ -27,12 +27,14 @@ import (
 )
 
 // Defaulter defines functions for setting defaults on resources.
+// Deprecated: Ue CustomDefaulter instead.
 type Defaulter interface {
 	runtime.Object
 	Default()
 }
 
 // DefaultingWebhookFor creates a new Webhook for Defaulting the provided type.
+// Deprecated: Use WithCustomDefaulter instead.
 func DefaultingWebhookFor(scheme *runtime.Scheme, defaulter Defaulter) *Webhook {
 	return &Webhook{
 		Handler: &mutatingHandler{defaulter: defaulter, decoder: NewDecoder(scheme)},

pkg/webhook/admission/validator.go

@@ -33,6 +33,7 @@ type Warnings []string
 // Validator defines functions for validating an operation.
 // The custom resource kind which implements this interface can validate itself.
 // To validate the custom resource with another specific struct, use CustomValidator instead.
+// Deprecated: Use CustomValidator instead.
 type Validator interface {
 	runtime.Object
 
@@ -53,6 +54,7 @@ type Validator interface {
 }
 
 // ValidatingWebhookFor creates a new Webhook for validating the provided type.
+// Deprecated: Use WithCustomValidator instead.
 func ValidatingWebhookFor(scheme *runtime.Scheme, validator Validator) *Webhook {
 	return &Webhook{
 		Handler: &validatingHandler{validator: validator, decoder: NewDecoder(scheme)},

pkg/webhook/admission/validator_custom.go

@@ -30,7 +30,6 @@ import (
 // CustomValidator defines functions for validating an operation.
 // The object to be validated is passed into methods as a parameter.
 type CustomValidator interface {
-
 	// ValidateCreate validates the object on creation.
 	// The optional warnings will be added to the response as warning messages.
 	// Return an error if the object is invalid.

pkg/webhook/alias.go

@@ -24,9 +24,11 @@ import (
 // define some aliases for common bits of the webhook functionality
 
 // Defaulter defines functions for setting defaults on resources.
+// Deprecated: Use CustomDefaulter instead.
 type Defaulter = admission.Defaulter
 
 // Validator defines functions for validating an operation.
+// Deprecated: Use CustomValidator instead.
 type Validator = admission.Validator
 
 // CustomDefaulter defines functions for setting defaults on resources.