go run watchers.go -kubeconfig ~/.kube/config

watchers.go

package main

import (
	"flag"
	"fmt"
	"log"

	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/pkg/api/v1"
	"k8s.io/client-go/pkg/watch"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/clientcmd"
)

var config *rest.Config

func buildConfig(kubeconfig string) (*rest.Config, error) {
	if kubeconfig != "" {
		return clientcmd.BuildConfigFromFlags("", kubeconfig)
	}
	return rest.InClusterConfig()
}

func main() {
	kubeconfig := flag.String("f", "", "Path to a kube config (usually: ~/.kube/config). Only required if out-of-cluster.")
	flag.Parse()

	config, err := buildConfig(*kubeconfig)
	if err != nil {
		log.Fatal(err)
	}

	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		log.Fatal(err)
	}

	eventsCh := make(chan watch.Event, 1)

	nsWatcher, err := clientset.Core().Namespaces().Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	nsEventsCh := nsWatcher.ResultChan()

	nodesWatcher, err := clientset.Core().Nodes().Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	nodesEventsCh := nodesWatcher.ResultChan()

	podsWatcher, err := clientset.Core().Pods("").Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	podsEventsCh := podsWatcher.ResultChan()

	secretsWatcher, err := clientset.Core().Secrets("").Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	secretsEventsCh := secretsWatcher.ResultChan()

	serviceWatcher, err := clientset.Core().Services("").Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	serviceEventsCh := serviceWatcher.ResultChan()

	eventsWatcher, err := clientset.Core().Events("").Watch(v1.ListOptions{})
	if err != nil {
		log.Fatal(err)
	}
	evEventsCh := eventsWatcher.ResultChan()

	go func(podsEventsCh, secretsEventsCh, nsEventsCh, serviceEventsCh, evEventsCh, nodesEventsCh <-chan watch.Event) {
		for {
			select {
			case event := <-evEventsCh:
				eventsCh <- event
			case event := <-podsEventsCh:
				eventsCh <- event
			case event := <-serviceEventsCh:
				eventsCh <- event
			case event := <-secretsEventsCh:
				eventsCh <- event
			case event := <-nsEventsCh:
				eventsCh <- event
			}
		}
	}(podsEventsCh, secretsEventsCh, nsEventsCh, serviceEventsCh, evEventsCh, nodesEventsCh)

	for {
		e := <-eventsCh
		if e.Type == watch.Added {
			fmt.Printf("%+v", e)
		}
	}
}