Initial v1.0.0 commit

vendor/sigs.k8s.io/controller-runtime/pkg/builder/webhook.go

@@ -0,0 +1,167 @@
+/*
+Copyright 2019 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 builder
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/rest"
+	"sigs.k8s.io/controller-runtime/pkg/client/apiutil"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/conversion"
+)
+
+// WebhookBuilder builds a Webhook.
+type WebhookBuilder struct {
+	apiType runtime.Object
+	gvk     schema.GroupVersionKind
+	mgr     manager.Manager
+	config  *rest.Config
+}
+
+// WebhookManagedBy allows inform its manager.Manager
+func WebhookManagedBy(m manager.Manager) *WebhookBuilder {
+	return &WebhookBuilder{mgr: m}
+}
+
+// TODO(droot): update the GoDoc for conversion.
+
+// For takes a runtime.Object which should be a CR.
+// If the given object implements the admission.Defaulter interface, a MutatingWebhook will be wired for this type.
+// If the given object implements the admission.Validator interface, a ValidatingWebhook will be wired for this type.
+func (blder *WebhookBuilder) For(apiType runtime.Object) *WebhookBuilder {
+	blder.apiType = apiType
+	return blder
+}
+
+// Complete builds the webhook.
+func (blder *WebhookBuilder) Complete() error {
+	// Set the Config
+	blder.loadRestConfig()
+
+	// Set the Webhook if needed
+	return blder.registerWebhooks()
+}
+
+func (blder *WebhookBuilder) loadRestConfig() {
+	if blder.config == nil {
+		blder.config = blder.mgr.GetConfig()
+	}
+}
+
+func (blder *WebhookBuilder) registerWebhooks() error {
+	// Create webhook(s) for each type
+	var err error
+	blder.gvk, err = apiutil.GVKForObject(blder.apiType, blder.mgr.GetScheme())
+	if err != nil {
+		return err
+	}
+
+	blder.registerDefaultingWebhook()
+	blder.registerValidatingWebhook()
+
+	err = blder.registerConversionWebhook()
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// registerDefaultingWebhook registers a defaulting webhook if th
+func (blder *WebhookBuilder) registerDefaultingWebhook() {
+	defaulter, isDefaulter := blder.apiType.(admission.Defaulter)
+	if !isDefaulter {
+		log.Info("skip registering a mutating webhook, admission.Defaulter interface is not implemented", "GVK", blder.gvk)
+		return
+	}
+	mwh := admission.DefaultingWebhookFor(defaulter)
+	if mwh != nil {
+		path := generateMutatePath(blder.gvk)
+
+		// Checking if the path is already registered.
+		// If so, just skip it.
+		if !blder.isAlreadyHandled(path) {
+			log.Info("Registering a mutating webhook",
+				"GVK", blder.gvk,
+				"path", path)
+			blder.mgr.GetWebhookServer().Register(path, mwh)
+		}
+	}
+}
+
+func (blder *WebhookBuilder) registerValidatingWebhook() {
+	validator, isValidator := blder.apiType.(admission.Validator)
+	if !isValidator {
+		log.Info("skip registering a validating webhook, admission.Validator interface is not implemented", "GVK", blder.gvk)
+		return
+	}
+	vwh := admission.ValidatingWebhookFor(validator)
+	if vwh != nil {
+		path := generateValidatePath(blder.gvk)
+
+		// Checking if the path is already registered.
+		// If so, just skip it.
+		if !blder.isAlreadyHandled(path) {
+			log.Info("Registering a validating webhook",
+				"GVK", blder.gvk,
+				"path", path)
+			blder.mgr.GetWebhookServer().Register(path, vwh)
+		}
+	}
+}
+
+func (blder *WebhookBuilder) registerConversionWebhook() error {
+	ok, err := conversion.IsConvertible(blder.mgr.GetScheme(), blder.apiType)
+	if err != nil {
+		log.Error(err, "conversion check failed", "object", blder.apiType)
+		return err
+	}
+	if ok {
+		if !blder.isAlreadyHandled("/convert") {
+			blder.mgr.GetWebhookServer().Register("/convert", &conversion.Webhook{})
+		}
+		log.Info("conversion webhook enabled", "object", blder.apiType)
+	}
+
+	return nil
+}
+
+func (blder *WebhookBuilder) isAlreadyHandled(path string) bool {
+	if blder.mgr.GetWebhookServer().WebhookMux == nil {
+		return false
+	}
+	h, p := blder.mgr.GetWebhookServer().WebhookMux.Handler(&http.Request{URL: &url.URL{Path: path}})
+	if p == path && h != nil {
+		return true
+	}
+	return false
+}
+
+func generateMutatePath(gvk schema.GroupVersionKind) string {
+	return "/mutate-" + strings.Replace(gvk.Group, ".", "-", -1) + "-" +
+		gvk.Version + "-" + strings.ToLower(gvk.Kind)
+}
+
+func generateValidatePath(gvk schema.GroupVersionKind) string {
+	return "/validate-" + strings.Replace(gvk.Group, ".", "-", -1) + "-" +
+		gvk.Version + "-" + strings.ToLower(gvk.Kind)
+}