pkg/plugins/runtime/k8s/webhooks/defaulter.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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"
	"encoding/json"
	"net/http"
)

import (
	"k8s.io/apimachinery/pkg/runtime"

	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
)

import (
	core_model "github.com/apache/dubbo-kubernetes/pkg/core/resources/model"
	"github.com/apache/dubbo-kubernetes/pkg/core/resources/registry"
	k8s_common "github.com/apache/dubbo-kubernetes/pkg/plugins/common/k8s"
	"github.com/apache/dubbo-kubernetes/pkg/plugins/runtime/k8s/metadata"
)

type Defaulter interface {
	core_model.Resource
	Default() error
}

func DefaultingWebhookFor(scheme *runtime.Scheme, converter k8s_common.Converter) *admission.Webhook {
	return &admission.Webhook{
		Handler: &defaultingHandler{
			converter: converter,
			decoder:   admission.NewDecoder(scheme),
		},
	}
}

type defaultingHandler struct {
	converter k8s_common.Converter
	decoder   *admission.Decoder
}

func (h *defaultingHandler) Handle(ctx context.Context, req admission.Request) admission.Response {
	resource, err := registry.Global().NewObject(core_model.ResourceType(req.Kind.Kind))
	if err != nil {
		return admission.Errored(http.StatusBadRequest, err)
	}

	obj, err := h.converter.ToKubernetesObject(resource)
	if err != nil {
		return admission.Errored(http.StatusInternalServerError, err)
	}

	err = h.decoder.Decode(req, obj)
	if err != nil {
		return admission.Errored(http.StatusBadRequest, err)
	}

	if err := h.converter.ToCoreResource(obj, resource); err != nil {
		return admission.Errored(http.StatusInternalServerError, err)
	}

	if defaulter, ok := resource.(Defaulter); ok {
		if err := defaulter.Default(); err != nil {
			return admission.Errored(http.StatusInternalServerError, err)
		}
	}

	obj, err = h.converter.ToKubernetesObject(resource)
	if err != nil {
		return admission.Errored(http.StatusInternalServerError, err)
	}

	if resource.Descriptor().Scope == core_model.ScopeMesh {
		labels := obj.GetLabels()
		if _, ok := labels[metadata.DubboMeshLabel]; !ok {
			if len(labels) == 0 {
				labels = map[string]string{}
			}
			labels[metadata.DubboMeshLabel] = core_model.DefaultMesh
			obj.SetLabels(labels)
		}
	}

	marshaled, err := json.Marshal(obj)
	if err != nil {
		return admission.Errored(http.StatusInternalServerError, err)
	}

	return admission.PatchResponseFromRaw(req.Object.Raw, marshaled)
}