Adding documentation for using unstructured for client and controller

pkg/client/example_test.go

@@ -0,0 +1,198 @@
+/*
+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 client_test
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/config"
+)
+
+var (
+	c client.Client
+)
+
+func ExampleNew() {
+	cl, err := client.New(config.GetConfigOrDie(), client.Options{})
+	if err != nil {
+		fmt.Println("failed to create client")
+		os.Exit(1)
+	}
+
+	podList := &corev1.PodList{}
+
+	err = cl.List(context.Background(), client.InNamespace("default"), podList)
+	if err != nil {
+		fmt.Printf("failed to list pods in namespace default: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+// This example shows how to use the client with typed and unstructured objects to retrieve a objects.
+func ExampleClient_get() {
+	// Using a typed object.
+	pod := &corev1.Pod{}
+	// c is a created client.
+	_ = c.Get(context.Background(), client.ObjectKey{
+		Namespace: "namespace",
+		Name:      "name",
+	}, pod)
+
+	// Using a unstructured object.
+	u := &unstructured.Unstructured{}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   "apps",
+		Kind:    "Deployment",
+		Version: "v1",
+	})
+	_ = c.Get(context.Background(), client.ObjectKey{
+		Namespace: "namespace",
+		Name:      "name",
+	}, u)
+}
+
+// This example shows how to use the client with typed and unstrucurted objects to create objects.
+func ExampleClient_create() {
+	// Using a typed object.
+	pod := &corev1.Pod{
+		ObjectMeta: v1.ObjectMeta{
+			Namespace: "namespace",
+			Name:      "name",
+		},
+		Spec: corev1.PodSpec{
+			Containers: []corev1.Container{
+				corev1.Container{
+					Image: "nginx",
+					Name:  "nginx",
+				},
+			},
+		},
+	}
+	// c is a created client.
+	_ = c.Create(context.Background(), pod)
+
+	// Using a unstructured object.
+	u := &unstructured.Unstructured{}
+	u.Object = map[string]interface{}{
+		"name":      "name",
+		"namespace": "namespace",
+		"spec": map[string]interface{}{
+			"replicas": 2,
+			"selector": map[string]interface{}{
+				"matchLabels": map[string]interface{}{
+					"foo": "bar",
+				},
+			},
+			"template": map[string]interface{}{
+				"labels": map[string]interface{}{
+					"foo": "bar",
+				},
+				"spec": map[string]interface{}{
+					"containers": []map[string]interface{}{
+						{
+							"name":  "nginx",
+							"image": "nginx",
+						},
+					},
+				},
+			},
+		},
+	}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   "apps",
+		Kind:    "Deployment",
+		Version: "v1",
+	})
+	_ = c.Create(context.Background(), u)
+}
+
+// This example shows how to use the client with typed and unstrucurted objects to list objects.
+func ExampleClient_list() {
+	// Using a typed object.
+	pod := &corev1.PodList{}
+	// c is a created client.
+	_ = c.List(context.Background(), nil, pod)
+
+	// Using a unstructured object.
+	u := &unstructured.UnstructuredList{}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   "apps",
+		Kind:    "DeploymentList",
+		Version: "v1",
+	})
+	_ = c.List(context.Background(), nil, u)
+}
+
+// This example shows how to use the client with typed and unstrucurted objects to update objects.
+func ExampleClient_update() {
+	// Using a typed object.
+	pod := &corev1.Pod{}
+	// c is a created client.
+	_ = c.Get(context.Background(), client.ObjectKey{
+		Namespace: "namespace",
+		Name:      "name",
+	}, pod)
+	pod.SetFinalizers(append(pod.GetFinalizers(), "new-finalizer"))
+	_ = c.Update(context.Background(), pod)
+
+	// Using a unstructured object.
+	u := &unstructured.Unstructured{}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   "apps",
+		Kind:    "Deployment",
+		Version: "v1",
+	})
+	_ = c.Get(context.Background(), client.ObjectKey{
+		Namespace: "namespace",
+		Name:      "name",
+	}, u)
+	u.SetFinalizers(append(u.GetFinalizers(), "new-finalizer"))
+	_ = c.Update(context.Background(), u)
+}
+
+// This example shows how to use the client with typed and unstrucurted objects to delete objects.
+func ExampleClient_delete() {
+	// Using a typed object.
+	pod := &corev1.Pod{
+		ObjectMeta: v1.ObjectMeta{
+			Namespace: "namespace",
+			Name:      "name",
+		},
+	}
+	// c is a created client.
+	_ = c.Delete(context.Background(), pod)
+
+	// Using a unstructured object.
+	u := &unstructured.Unstructured{}
+	u.Object = map[string]interface{}{
+		"name":      "name",
+		"namespace": "namespace",
+	}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Group:   "apps",
+		Kind:    "Deployment",
+		Version: "v1",
+	})
+	_ = c.Delete(context.Background(), u)
+}

pkg/controller/example_test.go

@@ -20,6 +20,8 @@ import (
 	"os"
 
 	"k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
 	"sigs.k8s.io/controller-runtime/pkg/controller"
 	"sigs.k8s.io/controller-runtime/pkg/handler"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
@@ -77,3 +79,37 @@ func ExampleController() {
 	// Start the Controller through the manager.
 	mgr.Start(signals.SetupSignalHandler())
 }
+
+// This example starts a new Controller named "pod-controller" to Watch Pods with the unstructured object and call a no-op Reconciler.
+func ExampleController_unstructured() {
+	// mgr is a manager.Manager
+
+	// Create a new Controller that will call the provided Reconciler function in response
+	// to events.
+	c, err := controller.New("pod-controller", mgr, controller.Options{
+		Reconciler: reconcile.Func(func(o reconcile.Request) (reconcile.Result, error) {
+			// Your business logic to implement the API by creating, updating, deleting objects goes here.
+			return reconcile.Result{}, nil
+		}),
+	})
+	if err != nil {
+		log.Error(err, "unable to create pod-controller")
+		os.Exit(1)
+	}
+
+	u := &unstructured.Unstructured{}
+	u.SetGroupVersionKind(schema.GroupVersionKind{
+		Kind:    "Pod",
+		Group:   "",
+		Version: "v1",
+	})
+	// Watch for Pod create / update / delete events and call Reconcile
+	err = c.Watch(&source.Kind{Type: u}, &handler.EnqueueRequestForObject{})
+	if err != nil {
+		log.Error(err, "unable to watch pods")
+		os.Exit(1)
+	}
+
+	// Start the Controller through the manager.
+	mgr.Start(signals.SetupSignalHandler())
+}