update demo

Signed-off-by: dragonflylee <dragonflylee@outlook.com>

tests/README.md

@@ -0,0 +1,11 @@
+
+```bash
+
+docker build --network host -t devkitpro/devkita64 - << EOF
+FROM devkitpro/devkita64:20231108
+RUN sed -i 's/deb.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.list \
+  && apt-get update && apt-get install -y --no-install-recommends nodejs \
+  && rm -rf /var/lib/apt/lists/* /usr/share/man/*
+EOF
+
+```

tests/ctrl/main.go

@@ -0,0 +1,62 @@
+package tests
+
+import (
+	"context"
+	"os"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/client/config"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+	"sigs.k8s.io/controller-runtime/pkg/source"
+)
+
+type podReconcile struct {
+	client.Client
+}
+
+func (r *podReconcile) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	rs := &appsv1.ReplicaSet{}
+	err := r.Get(ctx, req.NamespacedName, rs)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+	// DoSometing
+	return ctrl.Result{}, nil
+}
+
+func (r *podReconcile) InjectClient(c client.Client) error {
+	r.Client = c
+	return nil
+}
+
+func main() {
+	log := ctrl.Log.WithName("entrypoint")
+
+	// 初始化 manager，同时生成一个默认配置的 Cache
+	mgr, err := ctrl.NewManager(config.GetConfigOrDie(), ctrl.Options{})
+	if err != nil {
+		log.Error(err, "unable to set up overall controller manager")
+	}
+	// 注册 scheme
+	if err = corev1.AddToScheme(mgr.GetScheme()); err != nil {
+		log.Error(err, "unable to add scheme")
+	}
+
+	// 创建新的 controller
+	err = ctrl.NewControllerManagedBy(mgr).For(&appsv1.ReplicaSet{}).
+		// 当 Pod 变更时，也触发 ReplicaSet
+		Watches(&source.Kind{Type: &corev1.Pod{}}, &handler.EnqueueRequestForObject{}).
+		Complete(&podReconcile{})
+	if err != nil {
+		log.Error(err, "unable to add controller")
+	}
+
+	// 启动 manager
+	if err = mgr.Start(ctrl.SetupSignalHandler()); err != nil {
+		log.Error(err, "unable to run manager")
+		os.Exit(1)
+	}
+}

tests/informer/informer.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"path/filepath"
+
+	"k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/client-go/util/homedir"
+)
+
+func main() {
+	var kubeconfig string
+
+	flag.StringVar(&kubeconfig, "kubeconfig", filepath.Join(homedir.HomeDir(), ".kube", "config"), "(optional) absolute path to the kubeconfig file")
+	flag.Parse()
+	// use the current context in kubeconfig
+	config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ctx := context.Background()
+
+	AddPod := func(obj interface{}) {
+
+	}
+	DeletePod := func(obj interface{}) {
+
+	}
+	UpdatePod := func(oldObj, newObj interface{}) {
+
+	}
+
+	clientset := kubernetes.NewForConfigOrDie(config)
+	// 基于GVK 操作资源，假设需要操作数十种不同资源时，我们需要为每一种资源实现各自的函数
+	podInformer := informers.NewSharedInformerFactory(clientset, 0).
+		Core().V1().Pods().Informer()
+	podInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
+		AddFunc:    AddPod,
+		DeleteFunc: DeletePod,
+		UpdateFunc: UpdatePod,
+	})
+	// 启动informer
+	podInformer.Run(ctx.Done())
+	cache.WaitForCacheSync(ctx.Done(), podInformer.HasSynced)
+	// 此处没有使用workqueue，但一般都是会用workqueue 增强处理逻辑的
+}

tests/watch/watch.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"path/filepath"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/watch"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/tools/clientcmd"
+	"k8s.io/client-go/util/homedir"
+)
+
+func main() {
+	var kubeconfig string
+
+	flag.StringVar(&kubeconfig, "kubeconfig", filepath.Join(homedir.HomeDir(), ".kube", "config"), "(optional) absolute path to the kubeconfig file")
+	flag.Parse()
+	// use the current context in kubeconfig
+	config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	ctx := context.Background()
+	// 创建 clientset
+	clientset, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		log.Fatal(err)
+	}
+	// 使用 clientsent 监听 kube-system 下 Pod 对象
+	list, err := clientset.CoreV1().Pods("kube-system").
+		Watch(ctx, metav1.ListOptions{Watch: true})
+	if err != nil {
+		log.Fatal(err)
+	}
+	for event := range list.ResultChan() {
+		pod := event.Object.(*corev1.Pod)
+		switch event.Type {
+		case watch.Added:
+			fmt.Printf("Pod %s added\n", pod.Name)
+			// todo: reconcile logic goes here
+		case watch.Modified:
+			fmt.Printf("Pod %s modified\n", pod.Name)
+			// todo: reconcile logic goes here
+		case watch.Deleted:
+			fmt.Printf("Pod %s deleted\n", pod.Name)
+			// todo: reconcile logic goes here
+		}
+	}
+}