support custom API server address & CA bundle

Signed-off-by: Yang Le <[email protected]>

deploy/base/config.open-cluster-management.io_klusterletconfig.crd.yaml

@@ -36,6 +36,21 @@ spec:
           spec:
             description: Spec defines the desired state of KlusterletConfig
             properties:
+              hubKubeAPIServerCABundle:
+                description: 'HubKubeAPIServerCABundle is the CA bundle to verify
+                  the server certificate of the hub kube API against. If not present,
+                  CA bundle will be determined with the logic below: 1). Use the certificate
+                  of the named certificate configured in APIServer/cluster if FQDN
+                  matches; 2). Otherwise use the CA certificates from kube-root-ca.crt
+                  ConfigMap in the cluster namespace;'
+                format: byte
+                type: string
+              hubKubeAPIServerEndpoint:
+                description: HubKubeAPIServerURL is the URL of the hub Kube API server.
+                  If not present, the .status.apiServerURL of Infrastructure/cluster
+                  will be used as the default value. e.g. `oc get infrastructure cluster
+                  -o jsonpath='{.status.apiServerURL}'`
+                type: string
               hubKubeAPIServerProxyConfig:
                 description: HubKubeAPIServerProxyConfig holds proxy settings for
                   connections between klusterlet/add-on agents on the managed cluster

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/openshift/hive/apis v0.0.0-20230825202726-4418e43e27a3
 	github.com/openshift/library-go v0.0.0-20230809121909-d7e7beca5bae // https://github.com/openshift/library-go/tree/release-4.14
 	github.com/spf13/pflag v1.0.5
-	github.com/stolostron/cluster-lifecycle-api v0.0.0-20240109072430-f5fe6043d1f8
+	github.com/stolostron/cluster-lifecycle-api v0.0.0-20240123023750-d71a6437fb00
 	go.uber.org/zap v1.24.0
 	golang.org/x/text v0.9.0
 	k8s.io/api v0.27.4

go.sum

@@ -282,8 +282,8 @@ github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnIn
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stoewer/go-strcase v1.2.0/go.mod h1:IBiWB2sKIp3wVVQ3Y035++gc+knqhUQag1KpM8ahLw8=
-github.com/stolostron/cluster-lifecycle-api v0.0.0-20240109072430-f5fe6043d1f8 h1:DRFh4ML+WuDovJsrdgszqMQ4+qGznlYlX9/pItxWwQ8=
-github.com/stolostron/cluster-lifecycle-api v0.0.0-20240109072430-f5fe6043d1f8/go.mod h1:ZNQ3Rttgk4HEreCHfocrhXavLDaUgHbZaUqk5dP8/As=
+github.com/stolostron/cluster-lifecycle-api v0.0.0-20240123023750-d71a6437fb00 h1:q0DY1qdDPYWVrPiEeAIgzZRVt5DUCKae5f3ihBsEwkE=
+github.com/stolostron/cluster-lifecycle-api v0.0.0-20240123023750-d71a6437fb00/go.mod h1:ZNQ3Rttgk4HEreCHfocrhXavLDaUgHbZaUqk5dP8/As=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=

pkg/bootstrap/boostrapkubeconfig.go

@@ -46,12 +46,12 @@ func CreateBootstrapKubeConfig(ctx context.Context, clientHolder *helpers.Client
 		return nil, nil, err
 	}
 
-	kubeAPIServer, err := GetKubeAPIServerAddress(ctx, clientHolder.RuntimeClient)
+	kubeAPIServer, err := GetKubeAPIServerAddress(ctx, clientHolder.RuntimeClient, klusterletConfig)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	certData, err := GetBootstrapCAData(ctx, clientHolder, kubeAPIServer, ns)
+	certData, err := GetBootstrapCAData(ctx, clientHolder, kubeAPIServer, ns, klusterletConfig)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -162,8 +162,13 @@ func getBootstrapToken(ctx context.Context, kubeClient kubernetes.Interface,
 	return []byte(tokenRequest.Status.Token), expiration, nil
 }
 
-// GetKubeAPIServerAddress get the kube-apiserver URL from ocp infrastructure
-func GetKubeAPIServerAddress(ctx context.Context, client client.Client) (string, error) {
+func GetKubeAPIServerAddress(ctx context.Context, client client.Client,
+	klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig) (string, error) {
+	// use the custom hub Kube APIServer URL if specified
+	if klusterletConfig != nil && len(klusterletConfig.Spec.HubKubeAPIServerURL) > 0 {
+		return klusterletConfig.Spec.HubKubeAPIServerURL, nil
+	}
+
 	infraConfig := &ocinfrav1.Infrastructure{}
 	if err := client.Get(ctx, types.NamespacedName{Name: "cluster"}, infraConfig); err != nil {
 		return "", err
@@ -172,8 +177,14 @@ func GetKubeAPIServerAddress(ctx context.Context, client client.Client) (string,
 	return infraConfig.Status.APIServerURL, nil
 }
 
-func GetBootstrapCAData(ctx context.Context, clientHolder *helpers.ClientHolder, kubeAPIServer string, caNamespace string) ([]byte, error) {
-	// get the ca cert from ocp apiserver firstly
+func GetBootstrapCAData(ctx context.Context, clientHolder *helpers.ClientHolder, kubeAPIServer string,
+	caNamespace string, klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig) ([]byte, error) {
+	// use the custom hub Kube APIServer CA bundle if specified
+	if klusterletConfig != nil && len(klusterletConfig.Spec.HubKubeAPIServerCABundle) > 0 {
+		return klusterletConfig.Spec.HubKubeAPIServerCABundle, nil
+	}
+
+	// and then get the ca cert from ocp apiserver firstly
 	if u, err := url.Parse(kubeAPIServer); err == nil {
 		apiServerCertSecretName, err := getKubeAPIServerSecretName(ctx, clientHolder.RuntimeClient, u.Hostname())
 		if err != nil {

pkg/bootstrap/bootstrapkubeconfig_test.go

@@ -407,7 +407,8 @@ func TestGetKubeAPIServerAddress(t *testing.T) {
 	}
 
 	type args struct {
-		client client.Client
+		client           client.Client
+		klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig
 	}
 	tests := []struct {
 		name    string
@@ -431,10 +432,23 @@ func TestGetKubeAPIServerAddress(t *testing.T) {
 			want:    "http://127.0.0.1:6443",
 			wantErr: false,
 		},
+		{
+			name: "use custom address",
+			args: args{
+				client: fake.NewClientBuilder().WithScheme(testscheme).WithObjects(infraConfig).Build(),
+				klusterletConfig: &klusterletconfigv1alpha1.KlusterletConfig{
+					Spec: klusterletconfigv1alpha1.KlusterletConfigSpec{
+						HubKubeAPIServerURL: "https://api.acm.example.com:6443",
+					},
+				},
+			},
+			want:    "https://api.acm.example.com:6443",
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := GetKubeAPIServerAddress(context.Background(), tt.args.client)
+			got, err := GetKubeAPIServerAddress(context.Background(), tt.args.client, tt.args.klusterletConfig)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("getKubeAPIServerAddress() error = %v, wantErr %v", err, tt.wantErr)
 				return

pkg/controller/importconfig/cluster_info.go

@@ -48,7 +48,7 @@ func getBootstrapKubeConfigDataFromImportSecret(ctx context.Context, clientHolde
 	}
 
 	// check if the kube apiserver address is changed
-	validKubeAPIServer, err := validateKubeAPIServerAddress(ctx, kubeAPIServer, clientHolder)
+	validKubeAPIServer, err := validateKubeAPIServerAddress(ctx, kubeAPIServer, klusterletConfig, clientHolder)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to validate kube apiserver address: %v", err)
 	}
@@ -58,7 +58,7 @@ func getBootstrapKubeConfigDataFromImportSecret(ctx context.Context, clientHolde
 	}
 
 	// check if the CA data is changed
-	validCAData, err := validateCAData(ctx, caData, kubeAPIServer, clientHolder, clusterName)
+	validCAData, err := validateCAData(ctx, caData, kubeAPIServer, klusterletConfig, clientHolder, clusterName)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to validate CA data: %v", err)
 	}
@@ -130,26 +130,30 @@ func parseKubeConfigData(kubeConfigData []byte) (kubeAPIServer, proxyURL string,
 	return
 }
 
-func validateKubeAPIServerAddress(ctx context.Context, kubeAPIServer string, clientHolder *helpers.ClientHolder) (bool, error) {
+func validateKubeAPIServerAddress(ctx context.Context, kubeAPIServer string,
+	klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig,
+	clientHolder *helpers.ClientHolder) (bool, error) {
 	if len(kubeAPIServer) == 0 {
 		return false, nil
 	}
 
-	currentKubeAPIServer, err := bootstrap.GetKubeAPIServerAddress(ctx, clientHolder.RuntimeClient)
+	currentKubeAPIServer, err := bootstrap.GetKubeAPIServerAddress(ctx, clientHolder.RuntimeClient, klusterletConfig)
 	if err != nil {
 		return false, err
 	}
 
 	return kubeAPIServer == currentKubeAPIServer, nil
 }
 
-func validateCAData(ctx context.Context, caData []byte, kubeAPIServer string, clientHolder *helpers.ClientHolder, clusterName string) (bool, error) {
+func validateCAData(ctx context.Context, caData []byte, kubeAPIServer string,
+	klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig,
+	clientHolder *helpers.ClientHolder, clusterName string) (bool, error) {
 	if len(caData) == 0 {
 		// CA data is empty
 		return false, nil
 	}
 
-	currentCAData, err := bootstrap.GetBootstrapCAData(ctx, clientHolder, kubeAPIServer, clusterName)
+	currentCAData, err := bootstrap.GetBootstrapCAData(ctx, clientHolder, kubeAPIServer, clusterName, klusterletConfig)
 	if err != nil {
 		return false, err
 	}

pkg/controller/importconfig/cluster_info_test.go

@@ -264,6 +264,7 @@ func TestValidateKubeAPIServerAddress(t *testing.T) {
 		name               string
 		kubeAPIServer      string
 		infraKubeAPIServer string
+		klusterletConfig   *klusterletconfigv1alpha1.KlusterletConfig
 		valid              bool
 	}{
 		{
@@ -274,6 +275,15 @@ func TestValidateKubeAPIServerAddress(t *testing.T) {
 			kubeAPIServer:      "https://api.my-cluster.example.com:6443",
 			infraKubeAPIServer: "https://api-int.my-cluster.example.com:6443",
 		},
+		{
+			name:          "address overridden",
+			kubeAPIServer: "https://api.my-cluster.example.com:6443",
+			klusterletConfig: &klusterletconfigv1alpha1.KlusterletConfig{
+				Spec: klusterletconfigv1alpha1.KlusterletConfigSpec{
+					HubKubeAPIServerURL: "https://api.acm.example.com:6443",
+				},
+			},
+		},
 		{
 			name:               "no change",
 			kubeAPIServer:      "https://api.my-cluster.example.com:6443",
@@ -298,7 +308,7 @@ func TestValidateKubeAPIServerAddress(t *testing.T) {
 				}).Build(),
 			}
 
-			valid, err := validateKubeAPIServerAddress(context.TODO(), c.kubeAPIServer, clientHolder)
+			valid, err := validateKubeAPIServerAddress(context.TODO(), c.kubeAPIServer, c.klusterletConfig, clientHolder)
 			if err != nil {
 				t.Errorf("unexpected error: %v", err)
 			}
@@ -311,11 +321,12 @@ func TestValidateKubeAPIServerAddress(t *testing.T) {
 
 func TestValidateCAData(t *testing.T) {
 	cases := []struct {
-		name            string
-		clusterName     string
-		bootstrapCAData []byte
-		currentCAData   []byte
-		valid           bool
+		name             string
+		clusterName      string
+		bootstrapCAData  []byte
+		currentCAData    []byte
+		klusterletConfig *klusterletconfigv1alpha1.KlusterletConfig
+		valid            bool
 	}{
 		{
 			name: "CA data is empty",
@@ -325,6 +336,15 @@ func TestValidateCAData(t *testing.T) {
 			bootstrapCAData: []byte("my-ca-bundle"),
 			currentCAData:   []byte("my-new-ca-bundle"),
 		},
+		{
+			name:            "cert overridden",
+			bootstrapCAData: []byte("my-ca-bundle"),
+			klusterletConfig: &klusterletconfigv1alpha1.KlusterletConfig{
+				Spec: klusterletconfigv1alpha1.KlusterletConfigSpec{
+					HubKubeAPIServerCABundle: []byte("my-custom-ca-bundle"),
+				},
+			},
+		},
 		{
 			name:            "no cert change",
 			bootstrapCAData: []byte("my-ca-bundle"),
@@ -370,7 +390,7 @@ func TestValidateCAData(t *testing.T) {
 				KubeClient: fakeKubeClient,
 			}
 
-			valid, err := validateCAData(context.TODO(), c.bootstrapCAData, kubeAPIServer, clientHolder, "cluster")
+			valid, err := validateCAData(context.TODO(), c.bootstrapCAData, kubeAPIServer, c.klusterletConfig, clientHolder, "cluster")
 			if err != nil {
 				t.Errorf("unexpected error: %v", err)
 			}

test/e2e/e2e_suite_test.go

@@ -17,15 +17,19 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/onsi/ginkgo/v2"
 	"github.com/onsi/gomega"
+	ocinfrav1 "github.com/openshift/api/config/v1"
 	"github.com/openshift/library-go/pkg/operator/events"
 	corev1 "k8s.io/api/core/v1"
 	apiextensionsclient "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
 	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	k8sruntime "k8s.io/apimachinery/pkg/runtime"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	k8sscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 	certutil "k8s.io/client-go/util/cert"
@@ -58,8 +62,15 @@ var (
 	hubRuntimeClient       crclient.Client
 	hubRecorder            events.Recorder
 	hubMapper              meta.RESTMapper
+
+	scheme = k8sruntime.NewScheme()
 )
 
+func init() {
+	utilruntime.Must(k8sscheme.AddToScheme(scheme))
+	utilruntime.Must(ocinfrav1.AddToScheme(scheme))
+}
+
 func TestE2E(t *testing.T) {
 	gomega.RegisterFailHandler(ginkgo.Fail)
 	ginkgo.RunSpecs(t, "End-to-end Test Suite")
@@ -98,7 +109,9 @@ var _ = ginkgo.BeforeSuite(func() {
 	klusterletconfigClient, err = klusterletconfigclient.NewForConfig(clusterCfg)
 	gomega.Expect(err).Should(gomega.BeNil())
 
-	hubRuntimeClient, err = crclient.New(clusterCfg, crclient.Options{})
+	hubRuntimeClient, err = crclient.New(clusterCfg, crclient.Options{
+		Scheme: scheme,
+	})
 	gomega.Expect(err).Should(gomega.BeNil())
 
 	hubRecorder = helpers.NewEventRecorder(hubKubeClient, "e2e-test")
@@ -739,6 +752,40 @@ func assertBootstrapKubeconfigWithProxyConfig(proxyURL string, caDataIncluded, c
 	})
 }
 
+func assertBootstrapKubeconfigServerURLAndCABundle(serverURL string, caData []byte) {
+	ginkgo.By("Klusterlet should have bootstrap kubeconfig with expected serverURL & CA bundle", func() {
+		var bootstrapKubeconfigSecret *corev1.Secret
+		gomega.Eventually(func() error {
+			var err error
+			bootstrapKubeconfigSecret, err = hubKubeClient.CoreV1().Secrets("open-cluster-management-agent").Get(context.TODO(), "bootstrap-hub-kubeconfig", metav1.GetOptions{})
+			if err != nil {
+				return err
+			}
+
+			config, err := clientcmd.Load(bootstrapKubeconfigSecret.Data["kubeconfig"])
+			if err != nil {
+				return err
+			}
+
+			// check server url
+			cluster, ok := config.Clusters["default-cluster"]
+			if !ok {
+				return fmt.Errorf("default-cluster not found")
+			}
+			if cluster.Server != serverURL {
+				return fmt.Errorf("expected server url %q but got: %s", serverURL, cluster.Server)
+			}
+
+			// check ca data
+			if !reflect.DeepEqual(cluster.CertificateAuthorityData, caData) {
+				return fmt.Errorf("unexpected CA bundle is included in the bootstrap kubeconfig: open-cluster-management-agent/bootstrap-hub-kubeconfig")
+			}
+
+			return nil
+		}, 60*time.Second, 1*time.Second).Should(gomega.Succeed())
+	})
+}
+
 func hasCertificate(certs []*x509.Certificate, cert *x509.Certificate) bool {
 	if cert == nil {
 		return true