feat: add webhook CertWatcher and flags for custom certificate config…

…uration - Introduced CertWatcher for webhook server to dynamically reload certificates. - Added CLI flags (--webhook-cert-path, --webhook-cert-name, --webhook-cert-key) to allow users to provide custom certificate paths. - Updated manager to integrate CertWatcher into webhook TLS options. - Ensured backward compatibility with default self-signed certificates if no custom certs are provided.
camilamacedo86 · Dec 14, 2024 · 1421b14 · 1421b14
1 parent d240946
commit 1421b14
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Showing 27 changed files with 512 additions and 192 deletions.
diff --git a/.github/workflows/test-e2e-samples.yml b/.github/workflows/test-e2e-samples.yml
@@ -42,8 +42,8 @@ jobs:
           KUSTOMIZATION_FILE_PATH="testdata/project-v4/config/default/kustomization.yaml"
           sed -i '25s/^#//' $KUSTOMIZATION_FILE_PATH
           # Uncomment all cert-manager injections
-          sed -i '55,168s/^#//' $KUSTOMIZATION_FILE_PATH
-          sed -i '170,185s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '57,170s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '172,187s/^#//' $KUSTOMIZATION_FILE_PATH
           cd testdata/project-v4/
           go mod tidy
 
@@ -85,10 +85,10 @@ jobs:
           # Uncomment only ValidatingWebhookConfiguration
           # from cert-manager replaces; we are leaving defaulting uncommented
           # since this sample has no defaulting webhooks
-          sed -i '55,121s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '57,123s/^#//' $KUSTOMIZATION_FILE_PATH
           # Uncomment only --conversion webhooks CA injection
-          sed -i '153,168s/^#//' $KUSTOMIZATION_FILE_PATH
-          sed -i '170,185s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '155,170s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '172,187s/^#//' $KUSTOMIZATION_FILE_PATH
           cd testdata/project-v4-with-plugins/
           go mod tidy
 
@@ -128,8 +128,8 @@ jobs:
           KUSTOMIZATION_FILE_PATH="testdata/project-v4-multigroup/config/default/kustomization.yaml"
           sed -i '25s/^#//' $KUSTOMIZATION_FILE_PATH
           # Uncomment all cert-manager injections
-          sed -i '55,168s/^#//' $KUSTOMIZATION_FILE_PATH
-          sed -i '170,185s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '57,170s/^#//' $KUSTOMIZATION_FILE_PATH
+          sed -i '172,187s/^#//' $KUSTOMIZATION_FILE_PATH
           cd testdata/project-v4-multigroup
           go mod tidy
 

diff --git a/docs/book/src/cronjob-tutorial/testdata/project/cmd/main.go b/docs/book/src/cronjob-tutorial/testdata/project/cmd/main.go
@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"flag"
 	"os"
+	"path/filepath"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
@@ -30,6 +31,7 @@ import (
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/certwatcher"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
@@ -74,6 +76,7 @@ func main() {
 	/*
 	 */
 	var metricsAddr string
+	var webhookCertPath, webhookCertName, webhookCertKey string
 	var enableLeaderElection bool
 	var probeAddr string
 	var secureMetrics bool
@@ -87,6 +90,9 @@ func main() {
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.BoolVar(&secureMetrics, "metrics-secure", true,
 		"If set, the metrics endpoint is served securely via HTTPS. Use --metrics-secure=false to use HTTP instead.")
+	flag.StringVar(&webhookCertPath, "webhook-cert-path", "", "The directory that contains the webhook certificate.")
+	flag.StringVar(&webhookCertName, "webhook-cert-name", "tls.crt", "The name of the webhook certificate file.")
+	flag.StringVar(&webhookCertKey, "webhook-cert-key", "tls.key", "The name of the webhook key file.")
 	flag.BoolVar(&enableHTTP2, "enable-http2", false,
 		"If set, HTTP/2 will be enabled for the metrics and webhook servers")
 	opts := zap.Options{
@@ -112,8 +118,33 @@ func main() {
 		tlsOpts = append(tlsOpts, disableHTTP2)
 	}
 
+	// Create watchers for metrics certificates
+	var webhookCertWatcher *certwatcher.CertWatcher
+
+	// Initial webhook TLS options
+	webhookTLSOpts := append([]func(*tls.Config){}, tlsOpts...)
+
+	if len(webhookCertPath) > 0 {
+		setupLog.Info("Initializing webhook certificate watcher using provided certificates",
+			"webhook-cert-path", webhookCertPath, "webhook-cert-name", webhookCertName, "webhook-cert-key", webhookCertKey)
+
+		var err error
+		webhookCertWatcher, err = certwatcher.New(
+			filepath.Join(webhookCertPath, webhookCertName),
+			filepath.Join(webhookCertPath, webhookCertKey),
+		)
+		if err != nil {
+			setupLog.Error(err, "Failed to initialize webhook certificate watcher")
+			os.Exit(1)
+		}
+
+		webhookTLSOpts = append(webhookTLSOpts, func(config *tls.Config) {
+			config.GetCertificate = webhookCertWatcher.GetCertificate
+		})
+	}
+
 	webhookServer := webhook.NewServer(webhook.Options{
-		TLSOpts: tlsOpts,
+		TLSOpts: webhookTLSOpts,
 	})
 
 	// Metrics endpoint is enabled in 'config/default/kustomization.yaml'. The Metrics options configure the server.
@@ -196,6 +227,14 @@ func main() {
 	}
 	// +kubebuilder:scaffold:builder
 
+	if webhookCertWatcher != nil {
+		setupLog.Info("Adding webhook certificate watcher to manager")
+		if err := mgr.Add(webhookCertWatcher); err != nil {
+			setupLog.Error(err, "unable to add webhook certificate watcher to manager")
+			os.Exit(1)
+		}
+	}
+
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
 		setupLog.Error(err, "unable to set up health check")
 		os.Exit(1)

diff --git a/docs/book/src/cronjob-tutorial/testdata/project/config/default/kustomization.yaml b/docs/book/src/cronjob-tutorial/testdata/project/config/default/kustomization.yaml
@@ -49,6 +49,8 @@ patches:
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
 # crd/kustomization.yaml
 - path: manager_webhook_patch.yaml
+  target:
+    kind: Deployment
 
 # [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER' prefix.
 # Uncomment the following replacements to add the cert-manager CA injection annotations

diff --git a/docs/book/src/cronjob-tutorial/testdata/project/config/default/manager_webhook_patch.yaml b/docs/book/src/cronjob-tutorial/testdata/project/config/default/manager_webhook_patch.yaml
@@ -1,26 +1,32 @@
-apiVersion: apps/v1
-kind: Deployment
-metadata:
-  name: controller-manager
-  namespace: system
-  labels:
-    app.kubernetes.io/name: project
-    app.kubernetes.io/managed-by: kustomize
-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
+# This patch ensures the webhook certificates are properly mounted in the manager container.
+# It configures the necessary volume, volume mounts, and container ports.
+- op: add
+  path: /spec/template/spec/containers/0/args/-
+  value: --webhook-cert-path=/tmp/k8s-webhook-server/serving-certs
+- op: add
+  path: /spec/template/spec/containers/0/volumeMounts
+  value: []
+- op: add
+  path: /spec/template/spec/containers/0/volumeMounts/-
+  value:
+    mountPath: /tmp/k8s-webhook-server/serving-certs
+    name: webhook-certs
+    readOnly: true
+- op: add
+  path: /spec/template/spec/containers/0/ports
+  value: []
+- op: add
+  path: /spec/template/spec/containers/0/ports/-
+  value:
+    containerPort: 9443
+    name: webhook-server
+    protocol: TCP
+- op: add
+  path: /spec/template/spec/volumes
+  value: []
+- op: add
+  path: /spec/template/spec/volumes/-
+  value:
+    name: webhook-certs
+    secret:
+      secretName: webhook-server-cert
diff --git a/docs/book/src/cronjob-tutorial/testdata/project/dist/install.yaml b/docs/book/src/cronjob-tutorial/testdata/project/dist/install.yaml
@@ -4118,6 +4118,7 @@ spec:
         - --metrics-bind-address=:8443
         - --leader-elect
         - --health-probe-bind-address=:8081
+        - --webhook-cert-path=/tmp/k8s-webhook-server/serving-certs
         command:
         - /manager
         image: controller:latest
@@ -4152,7 +4153,7 @@ spec:
             - ALL
         volumeMounts:
         - mountPath: /tmp/k8s-webhook-server/serving-certs
-          name: cert
+          name: webhook-certs
           readOnly: true
       securityContext:
         runAsNonRoot: true
@@ -4161,9 +4162,8 @@ spec:
       serviceAccountName: project-controller-manager
       terminationGracePeriodSeconds: 10
       volumes:
-      - name: cert
+      - name: webhook-certs
         secret:
-          defaultMode: 420
           secretName: webhook-server-cert
 ---
 apiVersion: admissionregistration.k8s.io/v1

diff --git a/docs/book/src/getting-started/testdata/project/cmd/main.go b/docs/book/src/getting-started/testdata/project/cmd/main.go
@@ -20,6 +20,7 @@ import (
 	"crypto/tls"
 	"flag"
 	"os"
+	"path/filepath"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
@@ -29,6 +30,7 @@ import (
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/certwatcher"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
@@ -54,6 +56,7 @@ func init() {
 
 func main() {
 	var metricsAddr string
+	var webhookCertPath, webhookCertName, webhookCertKey string
 	var enableLeaderElection bool
 	var probeAddr string
 	var secureMetrics bool
@@ -67,6 +70,9 @@ func main() {
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.BoolVar(&secureMetrics, "metrics-secure", true,
 		"If set, the metrics endpoint is served securely via HTTPS. Use --metrics-secure=false to use HTTP instead.")
+	flag.StringVar(&webhookCertPath, "webhook-cert-path", "", "The directory that contains the webhook certificate.")
+	flag.StringVar(&webhookCertName, "webhook-cert-name", "tls.crt", "The name of the webhook certificate file.")
+	flag.StringVar(&webhookCertKey, "webhook-cert-key", "tls.key", "The name of the webhook key file.")
 	flag.BoolVar(&enableHTTP2, "enable-http2", false,
 		"If set, HTTP/2 will be enabled for the metrics and webhook servers")
 	opts := zap.Options{
@@ -92,8 +98,33 @@ func main() {
 		tlsOpts = append(tlsOpts, disableHTTP2)
 	}
 
+	// Create watchers for metrics certificates
+	var webhookCertWatcher *certwatcher.CertWatcher
+
+	// Initial webhook TLS options
+	webhookTLSOpts := append([]func(*tls.Config){}, tlsOpts...)
+
+	if len(webhookCertPath) > 0 {
+		setupLog.Info("Initializing webhook certificate watcher using provided certificates",
+			"webhook-cert-path", webhookCertPath, "webhook-cert-name", webhookCertName, "webhook-cert-key", webhookCertKey)
+
+		var err error
+		webhookCertWatcher, err = certwatcher.New(
+			filepath.Join(webhookCertPath, webhookCertName),
+			filepath.Join(webhookCertPath, webhookCertKey),
+		)
+		if err != nil {
+			setupLog.Error(err, "Failed to initialize webhook certificate watcher")
+			os.Exit(1)
+		}
+
+		webhookTLSOpts = append(webhookTLSOpts, func(config *tls.Config) {
+			config.GetCertificate = webhookCertWatcher.GetCertificate
+		})
+	}
+
 	webhookServer := webhook.NewServer(webhook.Options{
-		TLSOpts: tlsOpts,
+		TLSOpts: webhookTLSOpts,
 	})
 
 	// Metrics endpoint is enabled in 'config/default/kustomization.yaml'. The Metrics options configure the server.
@@ -158,6 +189,14 @@ func main() {
 	}
 	// +kubebuilder:scaffold:builder
 
+	if webhookCertWatcher != nil {
+		setupLog.Info("Adding webhook certificate watcher to manager")
+		if err := mgr.Add(webhookCertWatcher); err != nil {
+			setupLog.Error(err, "unable to add webhook certificate watcher to manager")
+			os.Exit(1)
+		}
+	}
+
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
 		setupLog.Error(err, "unable to set up health check")
 		os.Exit(1)

diff --git a/docs/book/src/getting-started/testdata/project/config/default/kustomization.yaml b/docs/book/src/getting-started/testdata/project/config/default/kustomization.yaml
@@ -49,6 +49,8 @@ patches:
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix including the one in
 # crd/kustomization.yaml
 #- path: manager_webhook_patch.yaml
+#  target:
+#    kind: Deployment
 
 # [CERTMANAGER] To enable cert-manager, uncomment all sections with 'CERTMANAGER' prefix.
 # Uncomment the following replacements to add the cert-manager CA injection annotations

diff --git a/docs/book/src/multiversion-tutorial/testdata/project/cmd/main.go b/docs/book/src/multiversion-tutorial/testdata/project/cmd/main.go
@@ -21,6 +21,7 @@ import (
 	"crypto/tls"
 	"flag"
 	"os"
+	"path/filepath"
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
@@ -31,6 +32,7 @@ import (
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/certwatcher"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
@@ -73,6 +75,7 @@ func main() {
 	/*
 	 */
 	var metricsAddr string
+	var webhookCertPath, webhookCertName, webhookCertKey string
 	var enableLeaderElection bool
 	var probeAddr string
 	var secureMetrics bool
@@ -86,6 +89,9 @@ func main() {
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.BoolVar(&secureMetrics, "metrics-secure", true,
 		"If set, the metrics endpoint is served securely via HTTPS. Use --metrics-secure=false to use HTTP instead.")
+	flag.StringVar(&webhookCertPath, "webhook-cert-path", "", "The directory that contains the webhook certificate.")
+	flag.StringVar(&webhookCertName, "webhook-cert-name", "tls.crt", "The name of the webhook certificate file.")
+	flag.StringVar(&webhookCertKey, "webhook-cert-key", "tls.key", "The name of the webhook key file.")
 	flag.BoolVar(&enableHTTP2, "enable-http2", false,
 		"If set, HTTP/2 will be enabled for the metrics and webhook servers")
 	opts := zap.Options{
@@ -111,8 +117,33 @@ func main() {
 		tlsOpts = append(tlsOpts, disableHTTP2)
 	}
 
+	// Create watchers for metrics certificates
+	var webhookCertWatcher *certwatcher.CertWatcher
+
+	// Initial webhook TLS options
+	webhookTLSOpts := append([]func(*tls.Config){}, tlsOpts...)
+
+	if len(webhookCertPath) > 0 {
+		setupLog.Info("Initializing webhook certificate watcher using provided certificates",
+			"webhook-cert-path", webhookCertPath, "webhook-cert-name", webhookCertName, "webhook-cert-key", webhookCertKey)
+
+		var err error
+		webhookCertWatcher, err = certwatcher.New(
+			filepath.Join(webhookCertPath, webhookCertName),
+			filepath.Join(webhookCertPath, webhookCertKey),
+		)
+		if err != nil {
+			setupLog.Error(err, "Failed to initialize webhook certificate watcher")
+			os.Exit(1)
+		}
+
+		webhookTLSOpts = append(webhookTLSOpts, func(config *tls.Config) {
+			config.GetCertificate = webhookCertWatcher.GetCertificate
+		})
+	}
+
 	webhookServer := webhook.NewServer(webhook.Options{
-		TLSOpts: tlsOpts,
+		TLSOpts: webhookTLSOpts,
 	})
 
 	// Metrics endpoint is enabled in 'config/default/kustomization.yaml'. The Metrics options configure the server.
@@ -199,6 +230,14 @@ func main() {
 	/*
 	 */
 
+	if webhookCertWatcher != nil {
+		setupLog.Info("Adding webhook certificate watcher to manager")
+		if err := mgr.Add(webhookCertWatcher); err != nil {
+			setupLog.Error(err, "unable to add webhook certificate watcher to manager")
+			os.Exit(1)
+		}
+	}
+
 	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
 		setupLog.Error(err, "unable to set up health check")
 		os.Exit(1)