[kubebuilder] Create validating admission webhook

PROJECT

@@ -17,4 +17,7 @@ resources:
   kind: Password
   path: example.com/password-operator/api/v1alpha1
   version: v1alpha1
+  webhooks:
+    validation: true
+    webhookVersion: v1
 version: "3"

api/v1alpha1/password_webhook.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2023.
+
+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 v1alpha1
+
+import (
+	"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"
+)
+
+// log is for logging in this package.
+var passwordlog = logf.Log.WithName("password-resource")
+
+// SetupWebhookWithManager will setup the manager to manage the webhooks
+func (r *Password) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewWebhookManagedBy(mgr).
+		For(r).
+		Complete()
+}
+
+// TODO(user): EDIT THIS FILE!  THIS IS SCAFFOLDING FOR YOU TO OWN!
+
+// TODO(user): change verbs to "verbs=create;update;delete" if you want to enable deletion validation.
+//+kubebuilder:webhook:path=/validate-secret-example-com-v1alpha1-password,mutating=false,failurePolicy=fail,sideEffects=None,groups=secret.example.com,resources=passwords,verbs=create;update,versions=v1alpha1,name=vpassword.kb.io,admissionReviewVersions=v1
+
+var _ webhook.Validator = &Password{}
+
+// ValidateCreate implements webhook.Validator so a webhook will be registered for the type
+func (r *Password) ValidateCreate() (admission.Warnings, error) {
+	passwordlog.Info("validate create", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object creation.
+	return nil, nil
+}
+
+// ValidateUpdate implements webhook.Validator so a webhook will be registered for the type
+func (r *Password) ValidateUpdate(old runtime.Object) (admission.Warnings, error) {
+	passwordlog.Info("validate update", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object update.
+	return nil, nil
+}
+
+// ValidateDelete implements webhook.Validator so a webhook will be registered for the type
+func (r *Password) ValidateDelete() (admission.Warnings, error) {
+	passwordlog.Info("validate delete", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object deletion.
+	return nil, nil
+}

api/v1alpha1/webhook_suite_test.go

@@ -0,0 +1,145 @@
+/*
+Copyright 2023.
+
+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 v1alpha1
+
+import (
+	"context"
+	"crypto/tls"
+	"fmt"
+	"net"
+	"path/filepath"
+	"runtime"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	admissionv1 "k8s.io/api/admission/v1"
+	//+kubebuilder:scaffold:imports
+	apimachineryruntime "k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/rest"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/envtest"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
+	"sigs.k8s.io/controller-runtime/pkg/webhook"
+)
+
+// These tests use Ginkgo (BDD-style Go testing framework). Refer to
+// http://onsi.github.io/ginkgo/ to learn more about Ginkgo.
+
+var cfg *rest.Config
+var k8sClient client.Client
+var testEnv *envtest.Environment
+var ctx context.Context
+var cancel context.CancelFunc
+
+func TestAPIs(t *testing.T) {
+	RegisterFailHandler(Fail)
+
+	RunSpecs(t, "Webhook Suite")
+}
+
+var _ = BeforeSuite(func() {
+	logf.SetLogger(zap.New(zap.WriteTo(GinkgoWriter), zap.UseDevMode(true)))
+
+	ctx, cancel = context.WithCancel(context.TODO())
+
+	By("bootstrapping test environment")
+	testEnv = &envtest.Environment{
+		CRDDirectoryPaths:     []string{filepath.Join("..", "..", "config", "crd", "bases")},
+		ErrorIfCRDPathMissing: false,
+
+		// The BinaryAssetsDirectory is only required if you want to run the tests directly
+		// without call the makefile target test. If not informed it will look for the
+		// default path defined in controller-runtime which is /usr/local/kubebuilder/.
+		// Note that you must have the required binaries setup under the bin directory to perform
+		// the tests directly. When we run make test it will be setup and used automatically.
+		BinaryAssetsDirectory: filepath.Join("..", "..", "bin", "k8s",
+			fmt.Sprintf("1.28.3-%s-%s", runtime.GOOS, runtime.GOARCH)),
+
+		WebhookInstallOptions: envtest.WebhookInstallOptions{
+			Paths: []string{filepath.Join("..", "..", "config", "webhook")},
+		},
+	}
+
+	var err error
+	// cfg is defined in this file globally.
+	cfg, err = testEnv.Start()
+	Expect(err).NotTo(HaveOccurred())
+	Expect(cfg).NotTo(BeNil())
+
+	scheme := apimachineryruntime.NewScheme()
+	err = AddToScheme(scheme)
+	Expect(err).NotTo(HaveOccurred())
+
+	err = admissionv1.AddToScheme(scheme)
+	Expect(err).NotTo(HaveOccurred())
+
+	//+kubebuilder:scaffold:scheme
+
+	k8sClient, err = client.New(cfg, client.Options{Scheme: scheme})
+	Expect(err).NotTo(HaveOccurred())
+	Expect(k8sClient).NotTo(BeNil())
+
+	// start webhook server using Manager
+	webhookInstallOptions := &testEnv.WebhookInstallOptions
+	mgr, err := ctrl.NewManager(cfg, ctrl.Options{
+		Scheme: scheme,
+		WebhookServer: webhook.NewServer(webhook.Options{
+			Host:    webhookInstallOptions.LocalServingHost,
+			Port:    webhookInstallOptions.LocalServingPort,
+			CertDir: webhookInstallOptions.LocalServingCertDir,
+		}),
+		LeaderElection: false,
+		Metrics:        metricsserver.Options{BindAddress: "0"},
+	})
+	Expect(err).NotTo(HaveOccurred())
+
+	err = (&Password{}).SetupWebhookWithManager(mgr)
+	Expect(err).NotTo(HaveOccurred())
+
+	//+kubebuilder:scaffold:webhook
+
+	go func() {
+		defer GinkgoRecover()
+		err = mgr.Start(ctx)
+		Expect(err).NotTo(HaveOccurred())
+	}()
+
+	// wait for the webhook server to get ready
+	dialer := &net.Dialer{Timeout: time.Second}
+	addrPort := fmt.Sprintf("%s:%d", webhookInstallOptions.LocalServingHost, webhookInstallOptions.LocalServingPort)
+	Eventually(func() error {
+		conn, err := tls.DialWithDialer(dialer, "tcp", addrPort, &tls.Config{InsecureSkipVerify: true})
+		if err != nil {
+			return err
+		}
+		return conn.Close()
+	}).Should(Succeed())
+
+})
+
+var _ = AfterSuite(func() {
+	cancel()
+	By("tearing down the test environment")
+	err := testEnv.Stop()
+	Expect(err).NotTo(HaveOccurred())
+})

cmd/main.go

@@ -96,6 +96,12 @@ func main() {
 		setupLog.Error(err, "unable to create controller", "controller", "Password")
 		os.Exit(1)
 	}
+	if os.Getenv("ENABLE_WEBHOOKS") != "false" {
+		if err = (&secretv1alpha1.Password{}).SetupWebhookWithManager(mgr); err != nil {
+			setupLog.Error(err, "unable to create webhook", "webhook", "Password")
+			os.Exit(1)
+		}
+	}
 	//+kubebuilder:scaffold:builder
 
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {

config/certmanager/certificate.yaml

@@ -0,0 +1,39 @@
+# The following manifests contain a self-signed issuer CR and a certificate CR.
+# More document can be found at https://docs.cert-manager.io
+# WARNING: Targets CertManager v1.0. Check https://cert-manager.io/docs/installation/upgrading/ for breaking changes.
+apiVersion: cert-manager.io/v1
+kind: Issuer
+metadata:
+  labels:
+    app.kubernetes.io/name: certificate
+    app.kubernetes.io/instance: serving-cert
+    app.kubernetes.io/component: certificate
+    app.kubernetes.io/created-by: password-operator
+    app.kubernetes.io/part-of: password-operator
+    app.kubernetes.io/managed-by: kustomize
+  name: selfsigned-issuer
+  namespace: system
+spec:
+  selfSigned: {}
+---
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  labels:
+    app.kubernetes.io/name: certificate
+    app.kubernetes.io/instance: serving-cert
+    app.kubernetes.io/component: certificate
+    app.kubernetes.io/created-by: password-operator
+    app.kubernetes.io/part-of: password-operator
+    app.kubernetes.io/managed-by: kustomize
+  name: serving-cert  # this name should match the one appeared in kustomizeconfig.yaml
+  namespace: system
+spec:
+  # SERVICE_NAME and SERVICE_NAMESPACE will be substituted by kustomize
+  dnsNames:
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc.cluster.local
+  issuerRef:
+    kind: Issuer
+    name: selfsigned-issuer
+  secretName: webhook-server-cert # this secret will not be prefixed, since it's not managed by kustomize

config/certmanager/kustomization.yaml

@@ -0,0 +1,5 @@
+resources:
+- certificate.yaml
+
+configurations:
+- kustomizeconfig.yaml

config/certmanager/kustomizeconfig.yaml

@@ -0,0 +1,8 @@
+# This configuration is for teaching kustomize how to update name ref substitution
+nameReference:
+- kind: Issuer
+  group: cert-manager.io
+  fieldSpecs:
+  - kind: Certificate
+    group: cert-manager.io
+    path: spec/issuerRef/name

config/crd/kustomization.yaml

@@ -8,7 +8,7 @@ resources:
 patches:
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix.
 # patches here are for enabling the conversion webhook for each CRD
-#- path: patches/webhook_in_passwords.yaml
+- path: patches/webhook_in_passwords.yaml
 #+kubebuilder:scaffold:crdkustomizewebhookpatch
 
 # [CERTMANAGER] To enable cert-manager, uncomment all the sections with [CERTMANAGER] prefix.
@@ -19,5 +19,5 @@ patches:
 # [WEBHOOK] To enable webhook, uncomment the following section
 # the following config is for teaching kustomize how to do kustomization for CRDs.
 
-#configurations:
-#- kustomizeconfig.yaml
+configurations:
+- kustomizeconfig.yaml

config/crd/patches/cainjection_in_passwords.yaml

@@ -0,0 +1,7 @@
+# The following patch adds a directive for certmanager to inject CA into the CRD
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    cert-manager.io/inject-ca-from: CERTIFICATE_NAMESPACE/CERTIFICATE_NAME
+  name: passwords.secret.example.com

config/crd/patches/webhook_in_passwords.yaml

@@ -0,0 +1,16 @@
+# The following patch enables a conversion webhook for the CRD
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  name: passwords.secret.example.com
+spec:
+  conversion:
+    strategy: Webhook
+    webhook:
+      clientConfig:
+        service:
+          namespace: system
+          name: webhook-service
+          path: /convert
+      conversionReviewVersions:
+      - v1

config/default/kustomization.yaml

@@ -20,7 +20,7 @@ resources:
 - ../manager
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
 # crd/kustomization.yaml
-#- ../webhook
+- ../webhook
 # [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER'. 'WEBHOOK' components are required.
 #- ../certmanager
 # [PROMETHEUS] To enable prometheus monitor, uncomment all sections with 'PROMETHEUS'.
@@ -34,7 +34,7 @@ patches:
 
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
 # crd/kustomization.yaml
-#- path: manager_webhook_patch.yaml
+- path: manager_webhook_patch.yaml
 
 # [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER'.
 # Uncomment 'CERTMANAGER' sections in crd/kustomization.yaml to enable the CA injection in the admission webhooks.

config/default/manager_webhook_patch.yaml

@@ -0,0 +1,23 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: controller-manager
+  namespace: system
+spec:
+  template:
+    spec:
+      containers:
+      - name: manager
+        ports:
+        - containerPort: 9443
+          name: webhook-server
+          protocol: TCP
+        volumeMounts:
+        - mountPath: /tmp/k8s-webhook-server/serving-certs
+          name: cert
+          readOnly: true
+      volumes:
+      - name: cert
+        secret:
+          defaultMode: 420
+          secretName: webhook-server-cert