./pod_informer -count=10 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=false -v=4
./pod_informer -count=20 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=false -v=4
./pod_informer -count=30 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=false -v=4
./pod_informer -count=40 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=false -v=4

./pod_informer -count=10 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=true -v=4
./pod_informer -count=20 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=true -v=4
./pod_informer -count=30 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=true -v=4
./pod_informer -count=40 -namespace=kube-system -timeout=2m -kubeconfig=/etc/kubernetes/kubeconfig -enableWatchListFeature=true -v=4

/*
Copyright 2023 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package main

import (
    "context"
    "flag"
    "os"
    "time"

    "k8s.io/apimachinery/pkg/util/wait"
    v1 "k8s.io/client-go/informers/core/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/tools/cache"
    "k8s.io/client-go/tools/clientcmd"
    "k8s.io/klog/v2"
)

var (
    kubeconfig                  string
    targetNamespace             string
    informerCount               int
    testTimeout                 time.Duration
    enableWatchListAlphaFeature bool
)

func main() {
    registerFlags()
    flag.Parse()

    klog.Info("The test binary started with the following arguments:")
    flag.VisitAll(func(f *flag.Flag) {
       klog.Infof("  -%s=%v (%s)\n", f.Name, f.Value, f.Usage)
    })

    if enableWatchListAlphaFeature {
       os.Setenv("ENABLE_CLIENT_GO_WATCH_LIST_ALPHA", "true")
    }

    ctx, cancel := context.WithTimeout(context.Background(), testTimeout)
    defer cancel()
    config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
    if err != nil {
       klog.Fatal(err)
    }
    config.AcceptContentTypes = "application/vnd.kubernetes.protobuf,application/json"
    config.ContentType = "application/vnd.kubernetes.protobuf"
	config.QPS = 100
	config.Burst = 200
    klog.Infof("The following Kubernetes client config will be used\n%v", config.String())

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


       ts := time.Now()
       ctxInformer, cancelInformers := context.WithCancel(ctx)
       defer cancelInformers()

       klog.Infof("Starting %d pod informers for targetNamespace = %s", informerCount, targetNamespace)
       informersSynced := startInformersFor(ctxInformer, client, informerCount, targetNamespace)

       klog.Info("Waiting for the pod informers to synced")
       cache.WaitForCacheSync(ctx.Done(), informersSynced...)
       klog.Infof("All %v pod informers synced, time needed = %v", len(informersSynced), time.Now().Sub(ts))


    klog.Info("Exiting the test app")
}

func registerFlags() {
    klog.InitFlags(flag.CommandLine)

    flag.StringVar(&kubeconfig, "kubeconfig", "", "path to kubeconfig.")
    flag.StringVar(&targetNamespace, "namespace", "", "namespace that host pods to list. If empty a default ('') value will be used.")
    flag.IntVar(&informerCount, "count", 4, "the number of informers per targetNamespace to run. If empty a default (4) value will be used.")
    flag.DurationVar(&testTimeout, "timeout", time.Minute, "timeout duration for the test")
    flag.BoolVar(&enableWatchListAlphaFeature, "enableWatchListFeature", false, "whether to set ENABLE_CLIENT_GO_WATCH_LIST_ALPHA env var")
}

func startInformersFor(ctx context.Context, client kubernetes.Interface, count int, namespace string) []cache.InformerSynced {
    var informersSynced []cache.InformerSynced
    for i := 0; i < count; i++ {
       inf := v1.NewPodInformer(client, namespace, time.Duration(0), cache.Indexers{})
       inf.SetTransform(func(interface{}) (interface{}, error) {
          return nil, nil
       })
       informersSynced = append(informersSynced, inf.HasSynced)
       go inf.Run(ctx.Done())
    }
    return informersSynced
}