Add remote.ClusterClient to access remote workload clusters

Signed-off-by: Vince Prignano <[email protected]>

Author: vincepri

pkg/controller/BUILD.bazel

@@ -6,6 +6,7 @@ go_library(
         "add_machinedeployment.go",
         "add_machineset.go",
         "add_node.go",
+        "add_noderef.go",
         "controller.go",
     ],
     importpath = "sigs.k8s.io/cluster-api/pkg/controller",
@@ -14,6 +15,7 @@ go_library(
         "//pkg/controller/machinedeployment:go_default_library",
         "//pkg/controller/machineset:go_default_library",
         "//pkg/controller/node:go_default_library",
+        "//vendor/sigs.k8s.io/cluster-api/pkg/controller/noderef:go_default_library",
         "//vendor/sigs.k8s.io/controller-runtime/pkg/manager:go_default_library",
     ],
 )

pkg/controller/remote/BUILD.bazel

@@ -2,22 +2,35 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["util.go"],
+    srcs = [
+        "cluster.go",
+        "util.go",
+    ],
     importpath = "sigs.k8s.io/cluster-api/pkg/controller/remote",
     visibility = ["//visibility:public"],
     deps = [
+        "//pkg/apis/cluster/v1alpha1:go_default_library",
         "//vendor/github.com/pkg/errors:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",
+        "//vendor/k8s.io/client-go/kubernetes/typed/core/v1:go_default_library",
+        "//vendor/k8s.io/client-go/rest:go_default_library",
+        "//vendor/k8s.io/client-go/tools/clientcmd:go_default_library",
         "//vendor/sigs.k8s.io/controller-runtime/pkg/client:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["util_test.go"],
+    srcs = [
+        "cluster_test.go",
+        "util_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
+        "//pkg/apis/cluster/v1alpha1:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/api/errors:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/sigs.k8s.io/controller-runtime/pkg/client/fake:go_default_library",
     ],

pkg/controller/remote/cluster.go

@@ -0,0 +1,68 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 remote
+
+import (
+	"github.com/pkg/errors"
+	corev1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	restclient "k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+	"sigs.k8s.io/cluster-api/pkg/apis/cluster/v1alpha1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// ClusterClient is a helper struct to connect to remote workload clusters.
+type ClusterClient struct {
+	restConfig *restclient.Config
+	cluster    *v1alpha1.Cluster
+}
+
+// NewClusterClient creates a new ClusterClient instance.
+func NewClusterClient(c client.Client, cluster *v1alpha1.Cluster) (*ClusterClient, error) {
+	secret, err := GetKubeConfigSecret(c, cluster.Name, cluster.Namespace)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to retrieve kubeconfig secret for Cluster %q in namespace %q",
+			cluster.Name, cluster.Namespace)
+	}
+
+	kubeconfig, err := DecodeKubeConfigSecret(secret)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to decode kubeconfig secret for Cluster %q in namespace %q",
+			cluster.Name, cluster.Namespace)
+	}
+
+	restConfig, err := clientcmd.RESTConfigFromKubeConfig(kubeconfig)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to create client configuration for Cluster %q in namespace %q",
+			cluster.Name, cluster.Namespace)
+	}
+
+	return &ClusterClient{
+		restConfig: restConfig,
+		cluster:    cluster,
+	}, nil
+}
+
+// RESTConfig returns a configuration instance to be used with a Kubernetes client.
+func (c *ClusterClient) RESTConfig() *restclient.Config {
+	return c.restConfig
+}
+
+// CoreV1 returns a new Kubernetes CoreV1 client.
+func (c *ClusterClient) CoreV1() (corev1.CoreV1Interface, error) {
+	return corev1.NewForConfig(c.RESTConfig())
+}

pkg/controller/remote/cluster_test.go

@@ -0,0 +1,85 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+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 remote
+
+import (
+	"testing"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/cluster-api/pkg/apis/cluster/v1alpha1"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
+)
+
+var (
+	clusterWithValidKubeConfig = &v1alpha1.Cluster{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test1",
+			Namespace: "test",
+		},
+	}
+
+	clusterWithInvalidKubeConfig = &v1alpha1.Cluster{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test2",
+			Namespace: "test",
+		},
+	}
+
+	clusterWithNoKubeConfig = &v1alpha1.Cluster{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test3",
+			Namespace: "test",
+		},
+	}
+)
+
+func TestNewClusterClient(t *testing.T) {
+	t.Run("cluster with valid kubeconfig", func(t *testing.T) {
+		client := fake.NewFakeClient(validSecret)
+		c, err := NewClusterClient(client, clusterWithValidKubeConfig)
+		if err != nil {
+			t.Fatalf("Expected no errors, got %v", err)
+		}
+
+		if c == nil {
+			t.Fatal("Expected actual client, got nil")
+		}
+
+		restConfig := c.RESTConfig()
+		if restConfig.Host != "https://test-cluster-api:6443" {
+			t.Fatalf("Unexpected Host value in RESTConfig: %q", restConfig.Host)
+		}
+	})
+
+	t.Run("cluster with no kubeconfig", func(t *testing.T) {
+		client := fake.NewFakeClient()
+		_, err := NewClusterClient(client, clusterWithNoKubeConfig)
+		if err == nil || !apierrors.IsNotFound(err) {
+			t.Fatalf("Expected not found error, got %v", err)
+		}
+	})
+
+	t.Run("cluster with invalid kubeconfig", func(t *testing.T) {
+		client := fake.NewFakeClient(invalidSecret)
+		_, err := NewClusterClient(client, clusterWithInvalidKubeConfig)
+		if err == nil || apierrors.IsNotFound(err) {
+			t.Fatalf("Expected error, got %v", err)
+		}
+	})
+
+}

pkg/controller/remote/util.go

@@ -23,13 +23,19 @@ import (
 
 	"github.com/pkg/errors"
 	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
 const (
 	kubeconfigSecretKey = "value"
 )
 
+var (
+	ErrSecretNotFound     = errors.New("secret not found")
+	ErrSecretMissingValue = errors.New("missing value in secret")
+)
+
 // KubeConfigSecretName generates the expected name for the Kubeconfig secret
 // to access a remote cluster given the cluster's name.
 func KubeConfigSecretName(cluster string) string {
@@ -46,6 +52,9 @@ func GetKubeConfigSecret(c client.Client, cluster, namespace string) (*corev1.Se
 	}
 
 	if err := c.Get(context.TODO(), secretKey, secret); err != nil {
+		if apierrors.IsNotFound(err) {
+			return nil, ErrSecretNotFound
+		}
 		return nil, err
 	}
 
@@ -56,12 +65,12 @@ func GetKubeConfigSecret(c client.Client, cluster, namespace string) (*corev1.Se
 func DecodeKubeConfigSecret(secret *corev1.Secret) ([]byte, error) {
 	encodedKubeconfig, ok := secret.Data[kubeconfigSecretKey]
 	if !ok {
-		return nil, errors.Errorf("missing value in secret %s/%s", secret.Namespace, secret.Name)
+		return nil, ErrSecretMissingValue
 	}
 
 	kubeconfig, err := base64.StdEncoding.DecodeString(string(encodedKubeconfig))
 	if err != nil {
-		return nil, errors.Wrapf(err, "cannot decode kubeconfig secret %s/%s", secret.Namespace, secret.Name)
+		return nil, err
 	}
 
 	return kubeconfig, nil

pkg/controller/remote/util_test.go

@@ -45,7 +45,7 @@ users:
 - name: kubernetes-admin
   user:
     client-certificate-data: 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
-	client-key-data: 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
+    client-key-data: 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
 `
 
 	validSecret = &corev1.Secret{