Remove kube-rbac-proxy dependency & adopt controller-runtime native auth for metric

Author: sujeet01

.github/workflows/test-e2e.yml

@@ -0,0 +1,32 @@
+name: E2E Tests
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test-e2e:
+    name: Run on Ubuntu
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clone the code
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: go.mod
+
+      - name: Install the latest version of kind
+        run: |
+          curl -Lo ./kind https://kind.sigs.k8s.io/dl/latest/kind-linux-amd64
+          chmod +x ./kind
+          sudo mv ./kind /usr/local/bin/kind
+
+      - name: Verify kind installation
+        run: kind version
+
+      - name: Running Test e2e
+        run: |
+          go mod tidy
+          make test-e2e

Makefile

@@ -62,6 +62,29 @@ vet: ## Run go vet against code.
 test: manifests generate fmt vet setup-envtest ## Run tests.
 	KUBEBUILDER_ASSETS="$(shell $(ENVTEST) use $(ENVTEST_K8S_VERSION) --bin-dir $(LOCALBIN) -p path)" go test $$(go list ./... | grep -v /e2e) -coverprofile cover.out
 
+# TODO(user): To use a different vendor for e2e tests, modify the setup under 'tests/e2e'.
+# The default setup assumes Kind is pre-installed and builds/loads the Manager Docker image locally.
+# CertManager is installed by default; skip with:
+# - CERT_MANAGER_INSTALL_SKIP=true
+KIND_CLUSTER ?= ipam
+
+.PHONY: setup-test-e2e
+setup-test-e2e: ## Set up a Kind cluster for e2e tests if it does not exist
+	@command -v $(KIND) >/dev/null 2>&1 || { \
+		echo "Kind is not installed. Please install Kind manually."; \
+		exit 1; \
+	}
+	$(KIND) create cluster --name $(KIND_CLUSTER)
+
+.PHONY: test-e2e
+test-e2e: setup-test-e2e manifests generate fmt vet ## Run the e2e tests. Expected an isolated environment using Kind.
+	KIND_CLUSTER=$(KIND_CLUSTER) go test ./test/e2e/ -v -ginkgo.v
+	$(MAKE) cleanup-test-e2e
+
+.PHONY: cleanup-test-e2e
+cleanup-test-e2e: ## Tear down the Kind cluster used for e2e tests
+	@$(KIND) delete cluster --name $(KIND_CLUSTER)
+
 .PHONY: add-license
 add-license: addlicense ## Add license headers to all go files.
 	find . -name '*.go' -exec $(ADDLICENSE) -f hack/license-header.txt {} +
@@ -96,7 +119,7 @@ run: manifests generate fmt vet ## Run a controller from your host.
 # (i.e. docker build --platform linux/arm64 ). However, you must enable docker buildKit for it.
 # More info: https://docs.docker.com/develop/develop-images/build_enhancements/
 .PHONY: docker-build
-docker-build: test ## Build docker image with the manager.
+docker-build: ## Build docker image with the manager.
 	docker build -t ${IMG} .
 
 .PHONY: docker-push
@@ -158,6 +181,7 @@ $(LOCALBIN):
 
 ## Tool Binaries
 KUBECTL ?= kubectl
+KIND ?= kind
 KUSTOMIZE ?= $(LOCALBIN)/kustomize
 CONTROLLER_GEN ?= $(LOCALBIN)/controller-gen
 ENVTEST ?= $(LOCALBIN)/setup-envtest

cmd/main.go

@@ -4,8 +4,10 @@
 package main
 
 import (
+	"crypto/tls"
 	"flag"
 	"os"
+	"path/filepath"
 
 	"github.com/ironcore-dev/ipam/internal/webhook/v1alpha1"
 
@@ -19,8 +21,10 @@ 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"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
 
 	ipamv1alpha1 "github.com/ironcore-dev/ipam/api/ipam/v1alpha1"
@@ -41,13 +45,28 @@ func init() {
 
 func main() {
 	var metricsAddr string
+	var secureMetrics bool
+	var metricsCertPath, metricsCertName, metricsCertKey string
+	var enableHTTP2 bool
 	var enableLeaderElection bool
 	var probeAddr string
-	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
+	var tlsOpts []func(*tls.Config)
+
+	flag.StringVar(&metricsAddr, "metrics-bind-address", "0", "The address the metrics endpoint binds to. "+
+		"Use :8443 for HTTPS or :8080 for HTTP, or leave as 0 to disable the metrics service.")
+	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(&metricsCertPath, "metrics-cert-path", "",
+		"The directory that contains the metrics server certificate.")
+	flag.StringVar(&metricsCertName, "metrics-cert-name", "tls.crt", "The name of the metrics server certificate file.")
+	flag.StringVar(&metricsCertKey, "metrics-cert-key", "tls.key", "The name of the metrics server key file.")
+	flag.BoolVar(&enableHTTP2, "enable-http2", false,
+		"If set, HTTP/2 will be enabled for the metrics server")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
+
 	opts := zap.Options{
 		Development: true,
 	}
@@ -56,11 +75,72 @@ func main() {
 
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
 
+	// if the enable-http2 flag is false (the default), http/2 should be disabled
+	// due to its vulnerabilities. More specifically, disabling http/2 will
+	// prevent from being vulnerable to the HTTP/2 Stream Cancellation and
+	// Rapid Reset CVEs. For more information see:
+	// - https://github.com/advisories/GHSA-qppj-fm5r-hxr3
+	// - https://github.com/advisories/GHSA-4374-p667-p6c8
+	disableHTTP2 := func(c *tls.Config) {
+		setupLog.Info("disabling http/2")
+		c.NextProtos = []string{"http/1.1"}
+	}
+
+	if !enableHTTP2 {
+		tlsOpts = append(tlsOpts, disableHTTP2)
+	}
+
+	// Create watchers for metrics and webhooks certificates
+	var metricsCertWatcher *certwatcher.CertWatcher
+
+	// Metrics endpoint is enabled in 'config/default/kustomization.yaml'. The Metrics options configure the server.
+	// More info:
+	// - https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.20.4/pkg/metrics/server
+	// - https://book.kubebuilder.io/reference/metrics.html
+	metricsServerOptions := metricsserver.Options{
+		BindAddress:   metricsAddr,
+		SecureServing: secureMetrics,
+		TLSOpts:       tlsOpts,
+	}
+
+	if secureMetrics {
+		// FilterProvider is used to protect the metrics endpoint with authn/authz.
+		// These configurations ensure that only authorized users and service accounts
+		// can access the metrics endpoint. The RBAC are configured in 'config/rbac/kustomization.yaml'. More info:
+		// https://pkg.go.dev/sigs.k8s.io/controller-runtime@v0.20.4/pkg/metrics/filters#WithAuthenticationAndAuthorization
+		metricsServerOptions.FilterProvider = filters.WithAuthenticationAndAuthorization
+	}
+
+	// If the certificate is not specified, controller-runtime will automatically
+	// generate self-signed certificates for the metrics server. While convenient for development and testing,
+	// this setup is not recommended for production.
+	//
+	// TODO(user): If you enable certManager, uncomment the following lines:
+	// - [METRICS-WITH-CERTS] at config/default/kustomization.yaml to generate and use certificates
+	// managed by cert-manager for the metrics server.
+	// - [PROMETHEUS-WITH-CERTS] at config/prometheus/kustomization.yaml for TLS certification.
+	if len(metricsCertPath) > 0 {
+		setupLog.Info("Initializing metrics certificate watcher using provided certificates",
+			"metrics-cert-path", metricsCertPath, "metrics-cert-name", metricsCertName, "metrics-cert-key", metricsCertKey)
+
+		var err error
+		metricsCertWatcher, err = certwatcher.New(
+			filepath.Join(metricsCertPath, metricsCertName),
+			filepath.Join(metricsCertPath, metricsCertKey),
+		)
+		if err != nil {
+			setupLog.Error(err, "to initialize metrics certificate watcher", "error", err)
+			os.Exit(1)
+		}
+
+		metricsServerOptions.TLSOpts = append(metricsServerOptions.TLSOpts, func(config *tls.Config) {
+			config.GetCertificate = metricsCertWatcher.GetCertificate
+		})
+	}
+
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
-		Scheme: scheme,
-		Metrics: metricsserver.Options{
-			BindAddress: metricsAddr,
-		},
+		Scheme:                 scheme,
+		Metrics:                metricsServerOptions,
 		HealthProbeBindAddress: probeAddr,
 		LeaderElection:         enableLeaderElection,
 		LeaderElectionID:       "f42c18d5.ironcore.dev",
@@ -122,6 +202,14 @@ func main() {
 	}
 	// +kubebuilder:scaffold:builder
 
+	if metricsCertWatcher != nil {
+		setupLog.Info("Adding metrics certificate watcher to manager")
+		if err := mgr.Add(metricsCertWatcher); err != nil {
+			setupLog.Error(err, "unable to add metrics 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)

config/certmanager/certificate-metrics.yaml

@@ -0,0 +1,17 @@
+# The following manifests contain a self-signed issuer CR and a metrics certificate CR.
+# More document can be found at https://docs.cert-manager.io
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: metrics-certs  # this name should match the one appeared in kustomizeconfig.yaml
+  namespace: system
+spec:
+  dnsNames:
+  # SERVICE_NAME and SERVICE_NAMESPACE will be substituted by kustomize
+  # replacements in the config/default/kustomization.yaml file.
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc.cluster.local
+  issuerRef:
+    kind: Issuer
+    name: selfsigned-issuer
+  secretName: metrics-server-cert

config/certmanager/certificate-webhook.yaml

@@ -0,0 +1,17 @@
+# The following manifests contain a self-signed issuer CR and a certificate CR.
+# More document can be found at https://docs.cert-manager.io
+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
+  # replacements in the config/default/kustomization.yaml file.
+  dnsNames:
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc
+  - SERVICE_NAME.SERVICE_NAMESPACE.svc.cluster.local
+  issuerRef:
+    kind: Issuer
+    name: selfsigned-issuer
+  secretName: webhook-server-cert

config/certmanager/certificate.yaml

@@ -0,0 +1,10 @@
+# The following manifest contains a self-signed issuer CR.
+# More information 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: {}

config/certmanager/issuer.yaml

@@ -1,5 +1,7 @@
 resources:
-- certificate.yaml
+- issuer.yaml
+- certificate-webhook.yaml
+- certificate-metrics.yaml
 
 configurations:
 - kustomizeconfig.yaml

config/certmanager/kustomization.yaml

@@ -1,16 +1,8 @@
-# This configuration is for teaching kustomize how to update name ref and var substitution 
+# 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
-
-varReference:
-- kind: Certificate
-  group: cert-manager.io
-  path: spec/commonName
-- kind: Certificate
-  group: cert-manager.io
-  path: spec/dnsNames

config/certmanager/kustomizeconfig.yaml

@@ -8,15 +8,15 @@ resources:
 - bases/ipam.metal.ironcore.dev_networkcounters.yaml
 #+kubebuilder:scaffold:crdkustomizeresource
 
-patchesStrategicMerge:
+patches:
 # [WEBHOOK] To enable webhook, uncomment all the sections with [WEBHOOK] prefix.
 # patches here are for enabling the conversion webhook for each CRD
 #- patches/webhook_in_ips.yaml
 #+kubebuilder:scaffold:crdkustomizewebhookpatch
 
 # [CERTMANAGER] To enable webhook, uncomment all the sections with [CERTMANAGER] prefix.
 # patches here are for enabling the CA injection for each CRD
-- patches/cainjection_in_ips.yaml
+- path: patches/cainjection_in_ips.yaml
 #+kubebuilder:scaffold:crdkustomizecainjectionpatch
 
 # the following config is for teaching kustomize how to do kustomization for CRDs.