Remove the usage of deprecated functions for webhooks

Motivation: kubernetes-sigs/controller-runtime#2877

Author: camilamacedo86

docs/book/src/cronjob-tutorial/cronjob_webhook_bkp.go

@@ -0,0 +1,277 @@
+/*
+Copyright 2024 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.
+*/
+// +kubebuilder:docs-gen:collapse=Apache License
+
+package v1
+
+import (
+	"context"
+	"fmt"
+	"github.com/robfig/cron"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	validationutils "k8s.io/apimachinery/pkg/util/validation"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	ctrl "sigs.k8s.io/controller-runtime"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/webhook"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+)
+
+// +kubebuilder:docs-gen:collapse=Go imports
+
+/*
+Next, we'll setup a logger for the webhooks.
+*/
+
+var cronjoblog = logf.Log.WithName("cronjob-resource")
+
+/*
+Then, we set up the webhook with the manager.
+*/
+
+// SetupWebhookWithManager will setup the manager to manage the webhooks
+func (r *CronJob) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewWebhookManagedBy(mgr).
+		For(r).
+		WithValidator(&CronJobCustomValidator{}).
+		WithDefaulter(&CronJobCustomDefaulter{}).
+		Complete()
+}
+
+/*
+Notice that we use kubebuilder markers to generate webhook manifests.
+This marker is responsible for generating a mutating webhook manifest.
+
+The meaning of each marker can be found [here](/reference/markers/webhook.md).
+*/
+
+// +kubebuilder:webhook:path=/mutate-batch-tutorial-kubebuilder-io-v1-cronjob,mutating=true,failurePolicy=fail,groups=batch.tutorial.kubebuilder.io,resources=cronjobs,verbs=create;update,versions=v1,name=mcronjob.kb.io,sideEffects=None,admissionReviewVersions=v1
+
+/*
+We use the `webhook.Defaulter` interface to set defaults to our CRD.
+A webhook will automatically be served that calls this defaulting.
+
+The `Default` method is expected to mutate the receiver, setting the defaults.
+*/
+
+type CronJobCustomDefaulter struct{}
+
+var _ webhook.CustomDefaulter = &CronJobCustomDefaulter{}
+
+// Default implements webhook.CustomDefaulter so a webhook will be registered for the type
+func (d *CronJobCustomDefaulter) Default(ctx context.Context, obj runtime.Object) error {
+	cronjoblog.Info("CustomDefaulter for CronJob")
+	req, err := admission.RequestFromContext(ctx)
+	if err != nil {
+		return fmt.Errorf("expected admission.Request in ctx: %w", err)
+	}
+	if req.Kind.Kind != "CronJob" {
+		return fmt.Errorf("expected Kind CronJob got %q", req.Kind.Kind)
+	}
+	castedObj, ok := obj.(*CronJob)
+	if !ok {
+		return fmt.Errorf("expected a CronJob object but got %T", obj)
+	}
+	cronjoblog.Info("default", "name", castedObj.GetName())
+
+	if castedObj.Spec.ConcurrencyPolicy == "" {
+		castedObj.Spec.ConcurrencyPolicy = AllowConcurrent
+	}
+	if castedObj.Spec.Suspend == nil {
+		castedObj.Spec.Suspend = new(bool)
+	}
+	if castedObj.Spec.SuccessfulJobsHistoryLimit == nil {
+		castedObj.Spec.SuccessfulJobsHistoryLimit = new(int32)
+		*castedObj.Spec.SuccessfulJobsHistoryLimit = 3
+	}
+	if castedObj.Spec.FailedJobsHistoryLimit == nil {
+		castedObj.Spec.FailedJobsHistoryLimit = new(int32)
+		*castedObj.Spec.FailedJobsHistoryLimit = 1
+	}
+
+	return nil
+}
+
+/*
+This marker is responsible for generating a validating webhook manifest.
+*/
+
+// +kubebuilder:webhook:verbs=create;update;delete,path=/validate-batch-tutorial-kubebuilder-io-v1-cronjob,mutating=false,failurePolicy=fail,groups=batch.tutorial.kubebuilder.io,resources=cronjobs,versions=v1,name=vcronjob.kb.io,sideEffects=None,admissionReviewVersions=v1
+
+/*
+We can validate our CRD beyond what's possible with declarative
+validation. Generally, declarative validation should be sufficient, but
+sometimes more advanced use cases call for complex validation.
+
+For instance, we'll see below that we use this to validate a well-formed cron
+schedule without making up a long regular expression.
+
+If `webhook.Validator` interface is implemented, a webhook will automatically be
+served that calls the validation.
+
+The `ValidateCreate`, `ValidateUpdate` and `ValidateDelete` methods are expected
+to validate its receiver upon creation, update and deletion respectively.
+We separate out ValidateCreate from ValidateUpdate to allow behavior like making
+certain fields immutable, so that they can only be set on creation.
+ValidateDelete is also separated from ValidateUpdate to allow different
+validation behavior on deletion.
+Here, however, we just use the same shared validation for `ValidateCreate` and
+`ValidateUpdate`. And we do nothing in `ValidateDelete`, since we don't need to
+validate anything on deletion.
+*/
+
+type CronJobCustomValidator struct{}
+
+var _ webhook.CustomValidator = &CronJobCustomValidator{}
+
+// ValidateCreate implements webhook.CustomValidator so a webhook will be registered for the type
+func (v *CronJobCustomValidator) ValidateCreate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
+	cronjoblog.Info("Creation Validation for CronJob")
+
+	req, err := admission.RequestFromContext(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("expected admission.Request in ctx: %w", err)
+	}
+	if req.Kind.Kind != "CronJob" {
+		return nil, fmt.Errorf("expected Kind CronJob got %q", req.Kind.Kind)
+	}
+	castedObj, ok := obj.(*CronJob)
+	if !ok {
+		return nil, fmt.Errorf("expected a CronJob object but got %T", obj)
+	}
+	cronjoblog.Info("default", "name", castedObj.GetName())
+
+	return nil, v.validateCronJob(castedObj)
+}
+
+// ValidateUpdate implements webhook.CustomValidator so a webhook will be registered for the type
+func (v *CronJobCustomValidator) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) (admission.Warnings, error) {
+	cronjoblog.Info("Update Validation for CronJob")
+	req, err := admission.RequestFromContext(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("expected admission.Request in ctx: %w", err)
+	}
+	if req.Kind.Kind != "CronJob" {
+		return nil, fmt.Errorf("expected Kind CronJob got %q", req.Kind.Kind)
+	}
+	castedObj, ok := newObj.(*CronJob)
+	if !ok {
+		return nil, fmt.Errorf("expected a CronJob object but got %T", newObj)
+	}
+	cronjoblog.Info("default", "name", castedObj.GetName())
+
+	return nil, v.validateCronJob(castedObj)
+}
+
+// ValidateDelete implements webhook.CustomValidator so a webhook will be registered for the type
+func (v *CronJobCustomValidator) ValidateDelete(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
+	cronjoblog.Info("Deletion Validation for CronJob")
+	req, err := admission.RequestFromContext(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("expected admission.Request in ctx: %w", err)
+	}
+	if req.Kind.Kind != "CronJob" {
+		return nil, fmt.Errorf("expected Kind CronJob got %q", req.Kind.Kind)
+	}
+	castedObj, ok := obj.(*CronJob)
+	if !ok {
+		return nil, fmt.Errorf("expected a CronJob object but got %T", obj)
+	}
+	cronjoblog.Info("default", "name", castedObj.GetName())
+
+	// TODO(user): fill in your validation logic upon object deletion.
+
+	return nil, nil
+}
+
+/*
+We validate the name and the spec of the CronJob.
+*/
+
+func (v *CronJobCustomValidator) validateCronJob(castedObj *CronJob) error {
+	var allErrs field.ErrorList
+	if err := v.validateCronJobName(castedObj); err != nil {
+		allErrs = append(allErrs, err)
+	}
+	if err := v.validateCronJobSpec(castedObj); err != nil {
+		allErrs = append(allErrs, err)
+	}
+	if len(allErrs) == 0 {
+		return nil
+	}
+
+	return apierrors.NewInvalid(
+		schema.GroupKind{Group: "batch.tutorial.kubebuilder.io", Kind: "CronJob"},
+		castedObj.Name, allErrs)
+}
+
+
+/*
+Some fields are declaratively validated by OpenAPI schema.
+You can find kubebuilder validation markers (prefixed
+with `// +kubebuilder:validation`) in the
+[Designing an API](api-design.md) section.
+You can find all of the kubebuilder supported markers for
+declaring validation by running `controller-gen crd -w`,
+or [here](/reference/markers/crd-validation.md).
+*/
+
+func (v *CronJobCustomValidator) validateCronJobSpec(castedObj *CronJob) *field.Error {
+	// The field helpers from the kubernetes API machinery help us return nicely
+	// structured validation errors.
+	return validateScheduleFormat(
+		castedObj.Spec.Schedule,
+		field.NewPath("spec").Child("schedule"))
+}
+
+/*
+We'll need to validate the [cron](https://en.wikipedia.org/wiki/Cron) schedule
+is well-formatted.
+*/
+
+func validateScheduleFormat(schedule string, fldPath *field.Path) *field.Error {
+	if _, err := cron.ParseStandard(schedule); err != nil {
+		return field.Invalid(fldPath, schedule, err.Error())
+	}
+	return nil
+}
+
+/*
+Validating the length of a string field can be done declaratively by
+the validation schema.
+
+But the `ObjectMeta.Name` field is defined in a shared package under
+the apimachinery repo, so we can't declaratively validate it using
+the validation schema.
+*/
+
+func (v *CronJobCustomValidator) validateCronJobName(castedObj *CronJob) *field.Error {
+	if len(castedObj.ObjectMeta.Name) > validationutils.DNS1035LabelMaxLength-11 {
+		// The job name length is 63 characters like all Kubernetes objects
+		// (which must fit in a DNS subdomain). The cronjob controller appends
+		// a 11-character suffix to the cronjob (`-$TIMESTAMP`) when creating
+		// a job. The job name length limit is 63 characters. Therefore cronjob
+		// names must have length <= 63-11=52. If we don't validate this here,
+		// then job creation will fail later.
+		return field.Invalid(field.NewPath("metadata").Child("name"), castedObj.Name, "must be no more than 52 characters")
+	}
+	return nil
+}
+
+// +kubebuilder:docs-gen:collapse=Validate object name