feat: add webhook

PROJECT

@@ -15,4 +15,8 @@ resources:
   kind: Application
   path: github.com/eminetto/k8s-operator-talk/api/v1alpha1
   version: v1alpha1
+  webhooks:
+    defaulting: true
+    validation: true
+    webhookVersion: v1
 version: "3"

api/v1alpha1/application_webhook.go

@@ -0,0 +1,75 @@
+/*
+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"
+)
+
+// log is for logging in this package.
+var applicationlog = logf.Log.WithName("application-resource")
+
+func (r *Application) SetupWebhookWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewWebhookManagedBy(mgr).
+		For(r).
+		Complete()
+}
+
+// TODO(user): EDIT THIS FILE!  THIS IS SCAFFOLDING FOR YOU TO OWN!
+
+//+kubebuilder:webhook:path=/mutate-minetto-dev-v1alpha1-application,mutating=true,failurePolicy=fail,sideEffects=None,groups=minetto.dev,resources=applications,verbs=create;update,versions=v1alpha1,name=mapplication.kb.io,admissionReviewVersions=v1
+
+var _ webhook.Defaulter = &Application{}
+
+// Default implements webhook.Defaulter so a webhook will be registered for the type
+func (r *Application) Default() {
+	applicationlog.Info("default", "name", r.Name)
+
+	// TODO(user): fill in your defaulting logic.
+}
+
+// TODO(user): change verbs to "verbs=create;update;delete" if you want to enable deletion validation.
+//+kubebuilder:webhook:path=/validate-minetto-dev-v1alpha1-application,mutating=false,failurePolicy=fail,sideEffects=None,groups=minetto.dev,resources=applications,verbs=create;update,versions=v1alpha1,name=vapplication.kb.io,admissionReviewVersions=v1
+
+var _ webhook.Validator = &Application{}
+
+// ValidateCreate implements webhook.Validator so a webhook will be registered for the type
+func (r *Application) ValidateCreate() error {
+	applicationlog.Info("validate create", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object creation.
+	return nil
+}
+
+// ValidateUpdate implements webhook.Validator so a webhook will be registered for the type
+func (r *Application) ValidateUpdate(old runtime.Object) error {
+	applicationlog.Info("validate update", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object update.
+	return nil
+}
+
+// ValidateDelete implements webhook.Validator so a webhook will be registered for the type
+func (r *Application) ValidateDelete() error {
+	applicationlog.Info("validate delete", "name", r.Name)
+
+	// TODO(user): fill in your validation logic upon object deletion.
+	return nil
+}

api/v1alpha1/webhook_suite_test.go

@@ -0,0 +1,135 @@
+/*
+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"
+	"testing"
+	"time"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	admissionv1beta1 "k8s.io/api/admission/v1beta1"
+	//+kubebuilder:scaffold:imports
+	"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"
+	"sigs.k8s.io/controller-runtime/pkg/envtest/printer"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+)
+
+// 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)
+
+	RunSpecsWithDefaultAndCustomReporters(t,
+		"Webhook Suite",
+		[]Reporter{printer.NewlineReporter{}})
+}
+
+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,
+		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 := runtime.NewScheme()
+	err = AddToScheme(scheme)
+	Expect(err).NotTo(HaveOccurred())
+
+	err = admissionv1beta1.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,
+		Host:               webhookInstallOptions.LocalServingHost,
+		Port:               webhookInstallOptions.LocalServingPort,
+		CertDir:            webhookInstallOptions.LocalServingCertDir,
+		LeaderElection:     false,
+		MetricsBindAddress: "0",
+	})
+	Expect(err).NotTo(HaveOccurred())
+
+	err = (&Application{}).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
+		}
+		conn.Close()
+		return nil
+	}).Should(Succeed())
+
+}, 60)
+
+var _ = AfterSuite(func() {
+	cancel()
+	By("tearing down the test environment")
+	err := testEnv.Stop()
+	Expect(err).NotTo(HaveOccurred())
+})

config/certmanager/certificate.yaml

@@ -0,0 +1,25 @@
+# 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:
+  name: selfsigned-issuer
+  namespace: system
+spec:
+  selfSigned: {}
+---
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  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 +1,16 @@
+# This configuration is for teaching kustomize how to update name ref and var substitution 
+nameReference:
+- kind: Issuer
+  group: cert-manager.io
+  fieldSpecs:
+  - kind: Certificate
+    group: cert-manager.io
+    path: spec/issuerRef/name
+
+varReference:
+- kind: Certificate
+  group: cert-manager.io
+  path: spec/commonName
+- kind: Certificate
+  group: cert-manager.io
+  path: spec/dnsNames

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

config/default/webhookcainjection_patch.yaml

@@ -0,0 +1,15 @@
+# This patch add annotation to admission webhook config and
+# the variables $(CERTIFICATE_NAMESPACE) and $(CERTIFICATE_NAME) will be substituted by kustomize.
+apiVersion: admissionregistration.k8s.io/v1
+kind: MutatingWebhookConfiguration
+metadata:
+  name: mutating-webhook-configuration
+  annotations:
+    cert-manager.io/inject-ca-from: $(CERTIFICATE_NAMESPACE)/$(CERTIFICATE_NAME)
+---
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingWebhookConfiguration
+metadata:
+  name: validating-webhook-configuration
+  annotations:
+    cert-manager.io/inject-ca-from: $(CERTIFICATE_NAMESPACE)/$(CERTIFICATE_NAME)

config/webhook/kustomization.yaml

@@ -0,0 +1,6 @@
+resources:
+- manifests.yaml
+- service.yaml
+
+configurations:
+- kustomizeconfig.yaml

config/webhook/kustomizeconfig.yaml

@@ -0,0 +1,25 @@
+# the following config is for teaching kustomize where to look at when substituting vars.
+# It requires kustomize v2.1.0 or newer to work properly.
+nameReference:
+- kind: Service
+  version: v1
+  fieldSpecs:
+  - kind: MutatingWebhookConfiguration
+    group: admissionregistration.k8s.io
+    path: webhooks/clientConfig/service/name
+  - kind: ValidatingWebhookConfiguration
+    group: admissionregistration.k8s.io
+    path: webhooks/clientConfig/service/name
+
+namespace:
+- kind: MutatingWebhookConfiguration
+  group: admissionregistration.k8s.io
+  path: webhooks/clientConfig/service/namespace
+  create: true
+- kind: ValidatingWebhookConfiguration
+  group: admissionregistration.k8s.io
+  path: webhooks/clientConfig/service/namespace
+  create: true
+
+varReference:
+- path: metadata/annotations

config/webhook/service.yaml

@@ -0,0 +1,13 @@
+
+apiVersion: v1
+kind: Service
+metadata:
+  name: webhook-service
+  namespace: system
+spec:
+  ports:
+    - port: 443
+      protocol: TCP
+      targetPort: 9443
+  selector:
+    control-plane: controller-manager

go.mod

@@ -3,6 +3,7 @@ module github.com/eminetto/k8s-operator-talk
 go 1.21
 
 require (
+	github.com/onsi/ginkgo v1.16.5
 	github.com/onsi/ginkgo/v2 v2.12.1
 	github.com/onsi/gomega v1.27.10
 	k8s.io/api v0.23.5
@@ -41,6 +42,7 @@ require (
 	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
+	github.com/nxadm/tail v1.4.8 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/prometheus/client_golang v1.11.0 // indirect
 	github.com/prometheus/client_model v0.2.0 // indirect
@@ -62,6 +64,7 @@ require (
 	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
+	gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/apiextensions-apiserver v0.23.5 // indirect