package main

import (
	"fmt"
	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	"log"
	"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() {
	config, err := rest.InClusterConfig()
	if err != nil {
		panic(err.Error())
	}
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}
	for {
		namespaces, err := clientset.CoreV1().Namespaces().List(metav1.ListOptions{})
		if err != nil {
			panic(err.Error())
		}

		for _, ns := range namespaces.Items {
			fmt.Printf("Checking for LimitRange named extreme-request-defaults in namespace '%v'\n", ns.Name)
			if limitRange, err := clientset.CoreV1().LimitRanges(ns.Name).List(metav1.ListOptions{FieldSelector:"metadata.name=extreme-request-defaults"}); err == nil && len(limitRange.Items) == 0 {
				fmt.Printf("Trying to create LimitaRange\n")
				limits := []v1.LimitRangeItem{
					{
						DefaultRequest:v1.ResourceList{"memory": *resource.NewQuantity(1024*1024*1024*1024, resource.BinarySI)},
					},
				}
				if _, err := clientset.CoreV1().LimitRanges(ns.Name).Create(&v1.LimitRange{Spec: v1.LimitRangeSpec{Limits: limits}}); err != nil {
					log.Printf("Unable to create LimitRange in namespace '%v'\n", ns.Name)
				}
			}
		}
		fmt.Printf("There are %d pods in the cluster\n", len(namespaces.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().Pods("default").Get("example-xxxxx", metav1.GetOptions{})
		if errors.IsNotFound(err) {
			fmt.Printf("Pod not found\n")
		} else if statusError, isStatus := err.(*errors.StatusError); isStatus {
			fmt.Printf("Error getting pod %v\n", statusError.ErrStatus.Message)
		} else if err != nil {
			panic(err.Error())
		} else {
			fmt.Printf("Found pod\n")
		}

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