dockermachinetemplate_webhook.go

/*
Copyright 2021 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.
*/

package webhooks

import (
	"context"
	"fmt"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/validation/field"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/webhook"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"

	"sigs.k8s.io/cluster-api/internal/util/compare"
	infrav1 "sigs.k8s.io/cluster-api/test/infrastructure/docker/api/v1beta1"
	"sigs.k8s.io/cluster-api/util/topology"
)

func (webhook *DockerMachineTemplate) SetupWebhookWithManager(mgr ctrl.Manager) error {
	return ctrl.NewWebhookManagedBy(mgr).
		For(&infrav1.DockerMachineTemplate{}).
		WithValidator(webhook).
		Complete()
}

// +kubebuilder:webhook:verbs=create;update,path=/validate-infrastructure-cluster-x-k8s-io-v1beta1-dockermachinetemplate,mutating=false,failurePolicy=fail,matchPolicy=Equivalent,groups=infrastructure.cluster.x-k8s.io,resources=dockermachinetemplates,versions=v1beta1,name=validation.dockermachinetemplate.infrastructure.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1

// DockerMachineTemplate implements a custom validation webhook for DockerMachineTemplate.
// +kubebuilder:object:generate=false
type DockerMachineTemplate struct{}

var _ webhook.CustomValidator = &DockerMachineTemplate{}

// ValidateCreate implements webhook.Validator so a webhook will be registered for the type.
func (webhook *DockerMachineTemplate) ValidateCreate(_ context.Context, raw runtime.Object) (admission.Warnings, error) {
	obj, ok := raw.(*infrav1.DockerMachineTemplate)
	if !ok {
		return nil, apierrors.NewBadRequest(fmt.Sprintf("expected a DockerMachineTemplate but got a %T", raw))
	}
	// Validate the metadata of the template.
	allErrs := obj.Spec.Template.ObjectMeta.Validate(field.NewPath("spec", "template", "metadata"))
	if len(allErrs) > 0 {
		return nil, apierrors.NewInvalid(infrav1.GroupVersion.WithKind("DockerClusterTemplate").GroupKind(), obj.Name, allErrs)
	}
	return nil, nil
}

// ValidateUpdate implements webhook.Validator so a webhook will be registered for the type.
func (webhook *DockerMachineTemplate) ValidateUpdate(ctx context.Context, oldRaw runtime.Object, newRaw runtime.Object) (admission.Warnings, error) {
	newObj, ok := newRaw.(*infrav1.DockerMachineTemplate)
	if !ok {
		return nil, apierrors.NewBadRequest(fmt.Sprintf("expected a DockerMachineTemplate but got a %T", newRaw))
	}
	oldObj, ok := oldRaw.(*infrav1.DockerMachineTemplate)
	if !ok {
		return nil, apierrors.NewBadRequest(fmt.Sprintf("expected a DockerMachineTemplate but got a %T", oldRaw))
	}

	req, err := admission.RequestFromContext(ctx)
	if err != nil {
		return nil, apierrors.NewBadRequest(fmt.Sprintf("expected a admission.Request inside context: %v", err))
	}

	var allErrs field.ErrorList
	if !topology.ShouldSkipImmutabilityChecks(req, newObj) {
		equal, diff, err := compare.Diff(oldObj.Spec.Template.Spec, newObj.Spec.Template.Spec)
		if err != nil {
			return nil, apierrors.NewBadRequest(fmt.Sprintf("failed to compare old and new DockerMachineTemplate: %v", err))
		}
		if !equal {
			allErrs = append(allErrs,
				field.Invalid(field.NewPath("spec", "template", "spec"), newObj, fmt.Sprintf("DockerMachineTemplate spec.template.spec field is immutable. Please create a new resource instead. Diff: %s", diff)),
			)
		}
	}

	// Validate the metadata of the template.
	allErrs = append(allErrs, newObj.Spec.Template.ObjectMeta.Validate(field.NewPath("spec", "template", "metadata"))...)

	if len(allErrs) == 0 {
		return nil, nil
	}
	return nil, apierrors.NewInvalid(infrav1.GroupVersion.WithKind("DockerMachineTemplate").GroupKind(), newObj.Name, allErrs)
}

// ValidateDelete implements webhook.Validator so a webhook will be registered for the type.
func (webhook *DockerMachineTemplate) ValidateDelete(_ context.Context, _ runtime.Object) (admission.Warnings, error) {
	return nil, nil
}