kubectl-lastrestarts.go

package main

import (
	"flag"
	"fmt"
	"os/user"
	"path/filepath"
	"sort"
	"time"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes"
	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp" // Import is necessary in order to support GKE
	"k8s.io/client-go/tools/clientcmd"
)

func main() {
	var kubeconfig *string

	u, err := user.Current()
	if err != nil {
		panic(err.Error())
	}

	if home := u.HomeDir; home != "" {
		kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
	} else {
		kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
	}

	filter := flag.String("l", "", "label selector, as in kubectl -l")
	namespace := flag.String("n", "default", "namespace selector, as in kubectl -n")
	allNamespaces := flag.Bool("A", false, "use all namespaces")

	flag.Parse()

	// If allNamespaces flag was provided, overwrite "namespace" flag as empty string
	if *allNamespaces {
		*namespace = ""
	}

	// use the current context in kubeconfig
	config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
	if err != nil {
		panic(err.Error())
	}

	// create the clientset
	clientset, err := kubernetes.NewForConfig(config)
	if err != nil {
		panic(err.Error())
	}

	type record struct {
		name       string
		reason     string
		finishedAt time.Time
	}

	var records []record

	// Make our Kubernetes API call based on the current context
	pods, err := clientset.CoreV1().Pods(*namespace).List(metav1.ListOptions{LabelSelector: *filter})
	if err != nil {
		panic(err.Error())
	}

	// Extract the last terminated reason and time
	for _, pod := range pods.Items {
		for _, stat := range pod.Status.ContainerStatuses {
			terminated := stat.LastTerminationState.Terminated
			if terminated == nil {
				continue
			}

			records = append(records, record{
				name:       pod.Name,
				reason:     terminated.Reason,
				finishedAt: terminated.FinishedAt.Time,
			})
		}
	}

	// Sort and output our exist reasons
	sort.Slice(records, func(i, j int) bool {
		return records[i].finishedAt.Before(records[j].finishedAt)
	})

	for _, rec := range records {
		fmt.Printf("%-40s  %-12s  %s  (%s ago)\n", rec.name, rec.reason, rec.finishedAt.Format(time.RFC3339), time.Since(rec.finishedAt))
	}
}