in-cluster.go

package main

import (
	"fmt"
	"time"

	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
)

func main() {
	// creates the in-cluster config
	config, err := rest.InClusterConfig()
	if err != nil {
		panic(err.Error())
	}
	// creates the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}
	for {
		nodes, err := clientset.CoreV1().Nodes().List(metav1.ListOptions{})
		if err != nil {
			panic(err.Error())
		}
		fmt.Printf("There are %d pods in the cluster\n", len(nodes.Items))

		// Examples for error handling:
		// - Use helper functions like e.g. errors.IsNotFound()
		// - And/or cast to StatusError and use its properties like e.g. ErrStatus.Message
		_, err = clientset.CoreV1().Nodes().Get("example-xxxxx", metav1.GetOptions{})
		if errors.IsNotFound(err) {
			fmt.Printf("Node not found\n")
		} else if statusError, isStatus := err.(*errors.StatusError); isStatus {
			fmt.Printf("Error getting node %v\n", statusError.ErrStatus.Message)
		} else if err != nil {
			panic(err.Error())
		} else {
			fmt.Printf("Found node\n")
		}

		time.Sleep(10 * time.Second)
	}
}