main.go

package main

import (
	"context"
	"fmt"
	"path/filepath"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/client-go/dynamic"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/cache"
	"k8s.io/client-go/tools/clientcmd"
	"k8s.io/client-go/util/homedir"
)

func main() {
	var config *rest.Config
	var err error
	
	
	config, err = rest.InClusterConfig()
	if err != nil {
		var kubeconfig string
		if home := homedir.HomeDir(); home != "" {
			kubeconfig = filepath.Join(home, ".kube", "config")
		}
		config, err = clientcmd.BuildConfigFromFlags("", kubeconfig)
		if err != nil {
			fmt.Printf("Error building kubeconfig: %s\n", err)
			return
		}
	}

	dynClient, err := dynamic.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}

	thefoothebar := schema.GroupVersionResource{
		Group:    "myk8s.io",
		Version:  "v1",
		Resource: "thefoosthebars",
	}

	informer := cache.NewSharedIndexInformer(
		&cache.ListWatch{
			ListFunc: func(options metav1.ListOptions) (runtime.Object, error) {
				return dynClient.Resource(thefoothebar).Namespace("").List(context.TODO(), options)
			},
			WatchFunc: func(options metav1.ListOptions) (watch.Interface, error) {
				return dynClient.Resource(thefoothebar).Namespace("").Watch(context.TODO(), options)
			},
		},
		&unstructured.Unstructured{},
		0,
		cache.Indexers{},
	)

	informer.AddEventHandler(cache.ResourceEventHandlerFuncs{
		AddFunc: func(obj interface{}) {
			fmt.Println("Add event detected: obj", obj)
		},
		UpdateFunc: func(oldObj, newObj interface{}) {
			fmt.Println("Update event detected:", newObj)
		},
		DeleteFunc: func(obj interface{}) {
			fmt.Println("Update event detected:", obj)
		},
	})

	stop := make(chan struct{})
	defer close(stop)

	go informer.Run(stop)

	if !cache.WaitForCacheSync(stop, informer.HasSynced) {
		panic("Timeout waiting for cache sync")
	}

	fmt.Println("Custom Resource Controller started successfully")

	<-stop
}