Add webhook Secret and ValidatingWebhookConfiguration certificate man…

…agement (#2126)

* Add webhook Secret and ValidatingWebhookConfiguration management

cmd/manager/main.go

@@ -12,10 +12,11 @@ import (
 	"strings"
 	"time"
 
-	"github.com/elastic/cloud-on-k8s/pkg/about"
 	// allow gcp authentication
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 
+	"github.com/elastic/cloud-on-k8s/pkg/about"
+	estype "github.com/elastic/cloud-on-k8s/pkg/apis/elasticsearch/v1beta1"
 	"github.com/elastic/cloud-on-k8s/pkg/controller/apmserver"
 	asesassn "github.com/elastic/cloud-on-k8s/pkg/controller/apmserverelasticsearchassociation"
 	"github.com/elastic/cloud-on-k8s/pkg/controller/common/certificates"
@@ -26,21 +27,18 @@ import (
 	kbassn "github.com/elastic/cloud-on-k8s/pkg/controller/kibanaassociation"
 	"github.com/elastic/cloud-on-k8s/pkg/controller/license"
 	licensetrial "github.com/elastic/cloud-on-k8s/pkg/controller/license/trial"
+	"github.com/elastic/cloud-on-k8s/pkg/controller/webhook"
 	"github.com/elastic/cloud-on-k8s/pkg/dev"
 	"github.com/elastic/cloud-on-k8s/pkg/dev/portforward"
 	"github.com/elastic/cloud-on-k8s/pkg/utils/net"
-
-	// TODO (sabo): re-enable when webhooks are usable
-	// "github.com/elastic/cloud-on-k8s/pkg/webhook"
-
-	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
-	ctrl "sigs.k8s.io/controller-runtime"
-
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"k8s.io/client-go/kubernetes"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/cache"
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
 	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
 )
 
@@ -56,10 +54,12 @@ const (
 	CertValidityFlag       = "cert-validity"
 	CertRotateBeforeFlag   = "cert-rotate-before"
 
-	AutoInstallWebhooksFlag = "auto-install-webhooks"
-	OperatorNamespaceFlag   = "operator-namespace"
-	WebhookSecretFlag       = "webhook-secret"
-	WebhookPodsLabelFlag    = "webhook-pods-label"
+	OperatorNamespaceFlag = "operator-namespace"
+
+	ManageWebhookCertsFlag   = "manage-webhook-certs"
+	WebhookSecretFlag        = "webhook-secret"
+	WebhookConfigurationName = "elastic-webhook.k8s.elastic.co"
+	WebhookPort              = 9443
 
 	DebugHTTPServerListenAddressFlag = "debug-http-listen"
 )
@@ -123,20 +123,15 @@ func init() {
 		"Duration representing how long before expiration TLS certificates should be reissued",
 	)
 	Cmd.Flags().Bool(
-		AutoInstallWebhooksFlag,
+		ManageWebhookCertsFlag,
 		true,
-		"enables automatic webhook installation (RBAC permission for service, secret and validatingwebhookconfigurations needed)",
+		"enables automatic certificates management for the webhook. The Secret and the ValidatingWebhookConfiguration must be created before running the operator",
 	)
 	Cmd.Flags().String(
 		OperatorNamespaceFlag,
 		"",
 		"k8s namespace the operator runs in",
 	)
-	Cmd.Flags().String(
-		WebhookPodsLabelFlag,
-		"",
-		"k8s label to select pods running the operator",
-	)
 	Cmd.Flags().String(
 		WebhookSecretFlag,
 		"",
@@ -236,6 +231,7 @@ func execute() {
 	}
 	opts.MetricsBindAddress = fmt.Sprintf(":%d", metricsPort) // 0 to disable
 
+	opts.Port = WebhookPort
 	mgr, err := ctrl.NewManager(cfg, opts)
 	if err != nil {
 		log.Error(err, "unable to create controller manager")
@@ -281,6 +277,10 @@ func execute() {
 		},
 	}
 
+	if operator.HasRole(operator.WebhookServer, roles) {
+		setupWebhook(mgr, params.CertRotation, clientset)
+	}
+
 	if operator.HasRole(operator.NamespaceOperator, roles) {
 		if err = apmserver.Add(mgr, params); err != nil {
 			log.Error(err, "unable to create controller", "controller", "ApmServer")
@@ -314,13 +314,6 @@ func execute() {
 		}
 	}
 
-	// TODO (sabo): re-enable when webhooks are usable
-	// log.Info("Setting up webhooks")
-	// if err := webhook.AddToManager(mgr, roles, newWebhookParameters); err != nil {
-	// 	log.Error(err, "unable to register webhooks to the manager")
-	// 	os.Exit(1)
-	// }
-
 	log.Info("Starting the manager", "uuid", operatorInfo.OperatorUUID,
 		"namespace", operatorNamespace, "version", operatorInfo.BuildInfo.Version,
 		"build_hash", operatorInfo.BuildInfo.Hash, "build_date", operatorInfo.BuildInfo.Date,
@@ -331,26 +324,6 @@ func execute() {
 	}
 }
 
-// TODO (sabo): re-enable when webhooks are usable
-// func newWebhookParameters() (*webhook.Parameters, error) {
-// 	autoInstall := viper.GetBool(AutoInstallWebhooksFlag)
-// 	ns := viper.GetString(OperatorNamespaceFlag)
-// 	if ns == "" && autoInstall {
-// 		return nil, fmt.Errorf("%s needs to be set for webhook auto installation", OperatorNamespaceFlag)
-// 	}
-// 	svcSelector := viper.GetString(WebhookPodsLabelFlag)
-// 	sec := viper.GetString(WebhookSecretFlag)
-// 	return &webhook.Parameters{
-// 		Bootstrap: webhook.NewBootstrapOptions(webhook.BootstrapOptionsParams{
-// 			Namespace:        ns,
-// 			ManagedNamespace: viper.GetString(NamespaceFlagName),
-// 			SecretName:       sec,
-// 			ServiceSelector:  svcSelector,
-// 		}),
-// 		AutoInstall: autoInstall,
-// 	}, nil
-// }
-
 func ValidateCertExpirationFlags(validityFlag string, rotateBeforeFlag string) (time.Duration, time.Duration) {
 	certValidity := viper.GetDuration(validityFlag)
 	certRotateBefore := viper.GetDuration(rotateBeforeFlag)
@@ -360,3 +333,33 @@ func ValidateCertExpirationFlags(validityFlag string, rotateBeforeFlag string) (
 	}
 	return certValidity, certRotateBefore
 }
+
+func setupWebhook(mgr manager.Manager, certRotation certificates.RotationParams, clientset kubernetes.Interface) {
+	manageWebhookCerts := viper.GetBool(ManageWebhookCertsFlag)
+	if manageWebhookCerts {
+		log.Info("Automatic management of the webhook certificates enabled")
+		// Ensure that all the certificates needed by the webhook server are already created
+		webhookParams := webhook.Params{
+			Namespace:                viper.GetString(OperatorNamespaceFlag),
+			SecretName:               viper.GetString(WebhookSecretFlag),
+			WebhookConfigurationName: WebhookConfigurationName,
+			Rotation:                 certRotation,
+		}
+
+		// Force a first reconciliation to create the resources before the server is started
+		if err := webhookParams.ReconcileResources(clientset); err != nil {
+			log.Error(err, "unable to setup and fill the webhook certificates")
+			os.Exit(1)
+		}
+
+		if err := webhook.Add(mgr, webhookParams, clientset); err != nil {
+			log.Error(err, "unable to create controller", "controller", webhook.ControllerName)
+			os.Exit(1)
+		}
+	}
+
+	if err := (&estype.Elasticsearch{}).SetupWebhookWithManager(mgr); err != nil {
+		log.Error(err, "unable to create webhook", "webhook", "Elasticsearch")
+		os.Exit(1)
+	}
+}

config/operator/all-in-one/operator.template.yaml

@@ -28,7 +28,7 @@ spec:
               fieldRef:
                 fieldPath: metadata.namespace
           - name: WEBHOOK_SECRET
-            value: webhook-server-secret
+            value: elastic-webhook-server-cert
           - name: WEBHOOK_PODS_LABEL
             value: elastic-operator
           - name: OPERATOR_IMAGE
@@ -41,7 +41,16 @@ spec:
             cpu: 100m
             memory: 50Mi
         ports:
-        - containerPort: 9876
+        - containerPort: 9443
           name: webhook-server
           protocol: TCP
+        volumeMounts:
+          - mountPath: /tmp/k8s-webhook-server/serving-certs
+            name: cert
+            readOnly: true
       terminationGracePeriodSeconds: 10
+      volumes:
+        - name: cert
+          secret:
+            defaultMode: 420
+            secretName: elastic-webhook-server-cert

config/operator/all-in-one/webhook.template.yaml

@@ -0,0 +1 @@
+../global/webhook.template.yaml

config/operator/global/operator.template.yaml

@@ -28,7 +28,7 @@ spec:
               fieldRef:
                 fieldPath: metadata.namespace
           - name: WEBHOOK_SECRET
-            value: webhook-server-secret
+            value: elastic-webhook-server-cert
           - name: WEBHOOK_PODS_LABEL
             value: elastic-global-operator
           - name: OPERATOR_IMAGE
@@ -41,8 +41,17 @@ spec:
             cpu: 100m
             memory: 20Mi
         ports:
-        - containerPort: 9876
+        - containerPort: 9443
           name: webhook-server
           protocol: TCP
+        volumeMounts:
+          - mountPath: /tmp/k8s-webhook-server/serving-certs
+            name: cert
+            readOnly: true
       terminationGracePeriodSeconds: 10
+      volumes:
+        - name: cert
+          secret:
+            defaultMode: 420
+            secretName: elastic-webhook-server-cert
 

config/operator/global/webhook.template.yaml

@@ -0,0 +1,42 @@
+apiVersion: admissionregistration.k8s.io/v1beta1
+kind: ValidatingWebhookConfiguration
+metadata:
+  name: elastic-webhook.k8s.elastic.co
+webhooks:
+  - clientConfig:
+      caBundle: Cg==
+      service:
+        name: elastic-webhook-server
+        namespace: <NAMESPACE>
+        # this is the path controller-runtime automatically generates
+        path: /validate-elasticsearch-k8s-elastic-co-v1beta1-elasticsearch
+    failurePolicy: Ignore
+    name: elastic-es-validation.k8s.elastic.co
+    rules:
+      - apiGroups:
+          - elasticsearch.k8s.elastic.co
+        apiVersions:
+          - v1beta1
+        operations:
+          - CREATE
+          - UPDATE
+        resources:
+          - elasticsearches
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: elastic-webhook-server
+  namespace: <NAMESPACE>
+spec:
+  ports:
+    - port: 443
+      targetPort: 9443
+  selector:
+    control-plane: elastic-operator
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: elastic-webhook-server-cert
+  namespace: <NAMESPACE>

config/webhook/manifests.yaml

@@ -13,7 +13,7 @@ webhooks:
       namespace: system
       path: /validate-elasticsearch
   failurePolicy: Ignore
-  name: elastic-es-validation
+  name: elastic-es-validation.k8s.elastic.co
   rules:
   - apiGroups:
     - elasticsearch.k8s.elastic.co

pkg/apis/elasticsearch/v1beta1/webhook.go

@@ -16,7 +16,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 )
 
-// +kubebuilder:webhook:path=/validate-elasticsearch,mutating=false,failurePolicy=ignore,groups=elasticsearch.k8s.elastic.co,resources=elasticsearches,verbs=create;update,versions=v1beta1,name=elastic-es-validation
+// +kubebuilder:webhook:path=/validate-elasticsearch,mutating=false,failurePolicy=ignore,groups=elasticsearch.k8s.elastic.co,resources=elasticsearches,verbs=create;update,versions=v1beta1,name=elastic-es-validation.k8s.elastic.co
 
 func (r *Elasticsearch) SetupWebhookWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewWebhookManagedBy(mgr).

pkg/controller/common/certificates/ca_reconcile.go

@@ -70,14 +70,14 @@ func ReconcileCAForOwner(
 	}
 
 	// build CA
-	ca := buildCAFromSecret(caInternalSecret)
+	ca := BuildCAFromSecret(caInternalSecret)
 	if ca == nil {
 		log.Info("Cannot build CA from secret, creating a new one", "owner_namespace", owner.GetNamespace(), "owner_name", owner.GetName(), "ca_type", caType)
 		return renewCA(cl, namer, owner, labels, rotationParams.Validity, scheme, caType)
 	}
 
 	// renew if cannot reuse
-	if !canReuseCA(ca, rotationParams.RotateBefore) {
+	if !CanReuseCA(ca, rotationParams.RotateBefore) {
 		log.Info("Cannot reuse existing CA, creating a new one", "owner_namespace", owner.GetNamespace(), "owner_name", owner.GetName(), "ca_type", caType)
 		return renewCA(cl, namer, owner, labels, rotationParams.Validity, scheme, caType)
 	}
@@ -125,14 +125,14 @@ func renewCA(
 	return ca, nil
 }
 
-// canReuseCA returns true if the given CA is valid for reuse
-func canReuseCA(ca *CA, expirationSafetyMargin time.Duration) bool {
-	return PrivateMatchesPublicKey(ca.Cert.PublicKey, *ca.PrivateKey) && certIsValid(*ca.Cert, expirationSafetyMargin)
+// CanReuseCA returns true if the given CA is valid for reuse
+func CanReuseCA(ca *CA, expirationSafetyMargin time.Duration) bool {
+	return PrivateMatchesPublicKey(ca.Cert.PublicKey, *ca.PrivateKey) && CertIsValid(*ca.Cert, expirationSafetyMargin)
 }
 
-// certIsValid returns true if the given cert is valid,
+// CertIsValid returns true if the given cert is valid,
 // according to a safety time margin.
-func certIsValid(cert x509.Certificate, expirationSafetyMargin time.Duration) bool {
+func CertIsValid(cert x509.Certificate, expirationSafetyMargin time.Duration) bool {
 	now := time.Now()
 	if now.Before(cert.NotBefore) {
 		log.Info("CA cert is not valid yet", "subject", cert.Subject)
@@ -166,9 +166,9 @@ func internalSecretForCA(
 	}
 }
 
-// buildCAFromSecret parses the given secret into a CA.
+// BuildCAFromSecret parses the given secret into a CA.
 // It returns nil if the secrets could not be parsed into a CA.
-func buildCAFromSecret(caInternalSecret corev1.Secret) *CA {
+func BuildCAFromSecret(caInternalSecret corev1.Secret) *CA {
 	if caInternalSecret.Data == nil {
 		return nil
 	}

pkg/controller/common/certificates/ca_reconcile_test.go

@@ -87,8 +87,8 @@ func Test_certIsValid(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := certIsValid(tt.cert, tt.safetyMargin); got != tt.want {
-				t.Errorf("certIsValid() = %v, want %v", got, tt.want)
+			if got := CertIsValid(tt.cert, tt.safetyMargin); got != tt.want {
+				t.Errorf("CertIsValid() = %v, want %v", got, tt.want)
 			}
 		})
 	}
@@ -134,8 +134,8 @@ func Test_canReuseCA(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := canReuseCA(tt.ca(), DefaultRotateBefore); got != tt.want {
-				t.Errorf("canReuseCA() = %v, want %v", got, tt.want)
+			if got := CanReuseCA(tt.ca(), DefaultRotateBefore); got != tt.want {
+				t.Errorf("CanReuseCA() = %v, want %v", got, tt.want)
 			}
 		})
 	}
@@ -152,7 +152,7 @@ func checkCASecrets(
 	expectedExpiration time.Duration,
 ) {
 	// ca cert should be valid
-	require.True(t, certIsValid(*ca.Cert, DefaultRotateBefore))
+	require.True(t, CertIsValid(*ca.Cert, DefaultRotateBefore))
 
 	// expiration date should be correctly set
 	require.True(t, ca.Cert.NotBefore.After(time.Now().Add(-1*time.Hour)))
@@ -181,7 +181,7 @@ func checkCASecrets(
 	require.NotEmpty(t, internalCASecret.Data[KeyFileName])
 
 	// secret should be ok to parse as a CA
-	parsedCa := buildCAFromSecret(internalCASecret)
+	parsedCa := BuildCAFromSecret(internalCASecret)
 	require.NotNil(t, parsedCa)
 	// and return the ca
 	require.True(t, ca.Cert.Equal(parsedCa.Cert))
@@ -377,7 +377,7 @@ func Test_buildCAFromSecret(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			ca := buildCAFromSecret(tt.internalSecret)
+			ca := BuildCAFromSecret(tt.internalSecret)
 			if !reflect.DeepEqual(ca, tt.wantCa) {
 				t.Errorf("CaFromSecrets() got = %v, want %v", ca, tt.wantCa)
 			}