/*
Copyright 2015 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 quota

import (
	"context"
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/fields"
	"k8s.io/apimachinery/pkg/labels"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/apiserver/pkg/admission/plugin/resourcequota"
	resourcequotaapi "k8s.io/apiserver/pkg/admission/plugin/resourcequota/apis/resourcequota"
	"k8s.io/apiserver/pkg/quota/v1/generic"
	"k8s.io/client-go/informers"
	clientset "k8s.io/client-go/kubernetes"
	restclient "k8s.io/client-go/rest"
	"k8s.io/client-go/tools/record"
	watchtools "k8s.io/client-go/tools/watch"
	"k8s.io/kubernetes/pkg/controller"
	replicationcontroller "k8s.io/kubernetes/pkg/controller/replication"
	resourcequotacontroller "k8s.io/kubernetes/pkg/controller/resourcequota"
	quotainstall "k8s.io/kubernetes/pkg/quota/v1/install"
	"k8s.io/kubernetes/test/integration/framework"
)

// 1.2 code gets:
// 	quota_test.go:95: Took 4.218619579s to scale up without quota
// 	quota_test.go:199: unexpected error: timed out waiting for the condition, ended with 342 pods (1 minute)
// 1.3+ code gets:
// 	quota_test.go:100: Took 4.196205966s to scale up without quota
// 	quota_test.go:115: Took 12.021640372s to scale up with quota
func TestQuota(t *testing.T) {
	// Set up a master
	h := &framework.MasterHolder{Initialized: make(chan struct{})}
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		<-h.Initialized
		h.M.GenericAPIServer.Handler.ServeHTTP(w, req)
	}))

	admissionCh := make(chan struct{})
	clientset := clientset.NewForConfigOrDie(&restclient.Config{QPS: -1, Host: s.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &schema.GroupVersion{Group: "", Version: "v1"}}})
	config := &resourcequotaapi.Configuration{}
	admission, err := resourcequota.NewResourceQuota(config, 5, admissionCh)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	admission.SetExternalKubeClientSet(clientset)
	internalInformers := informers.NewSharedInformerFactory(clientset, controller.NoResyncPeriodFunc())
	admission.SetExternalKubeInformerFactory(internalInformers)
	qca := quotainstall.NewQuotaConfigurationForAdmission()
	admission.SetQuotaConfiguration(qca)
	defer close(admissionCh)

	masterConfig := framework.NewIntegrationTestMasterConfig()
	masterConfig.GenericConfig.AdmissionControl = admission
	_, _, closeFn := framework.RunAMasterUsingServer(masterConfig, s, h)
	defer closeFn()

	ns := framework.CreateTestingNamespace("quotaed", s, t)
	defer framework.DeleteTestingNamespace(ns, s, t)
	ns2 := framework.CreateTestingNamespace("non-quotaed", s, t)
	defer framework.DeleteTestingNamespace(ns2, s, t)

	controllerCh := make(chan struct{})
	defer close(controllerCh)

	informers := informers.NewSharedInformerFactory(clientset, controller.NoResyncPeriodFunc())
	rm := replicationcontroller.NewReplicationManager(
		informers.Core().V1().Pods(),
		informers.Core().V1().ReplicationControllers(),
		clientset,
		replicationcontroller.BurstReplicas,
	)
	rm.SetEventRecorder(&record.FakeRecorder{})
	go rm.Run(3, controllerCh)

	discoveryFunc := clientset.Discovery().ServerPreferredNamespacedResources
	listerFuncForResource := generic.ListerFuncForResourceFunc(informers.ForResource)
	qc := quotainstall.NewQuotaConfigurationForControllers(listerFuncForResource)
	informersStarted := make(chan struct{})
	resourceQuotaControllerOptions := &resourcequotacontroller.ControllerOptions{
		QuotaClient:               clientset.CoreV1(),
		ResourceQuotaInformer:     informers.Core().V1().ResourceQuotas(),
		ResyncPeriod:              controller.NoResyncPeriodFunc,
		InformerFactory:           informers,
		ReplenishmentResyncPeriod: controller.NoResyncPeriodFunc,
		DiscoveryFunc:             discoveryFunc,
		IgnoredResourcesFunc:      qc.IgnoredResources,
		InformersStarted:          informersStarted,
		Registry:                  generic.NewRegistry(qc.Evaluators()),
	}
	resourceQuotaController, err := resourcequotacontroller.NewController(resourceQuotaControllerOptions)
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}
	go resourceQuotaController.Run(2, controllerCh)

	// Periodically the quota controller to detect new resource types
	go resourceQuotaController.Sync(discoveryFunc, 30*time.Second, controllerCh)

	internalInformers.Start(controllerCh)
	informers.Start(controllerCh)
	close(informersStarted)

	startTime := time.Now()
	scale(t, ns2.Name, clientset)
	endTime := time.Now()
	t.Logf("Took %v to scale up without quota", endTime.Sub(startTime))

	quota := &v1.ResourceQuota{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "quota",
			Namespace: ns.Name,
		},
		Spec: v1.ResourceQuotaSpec{
			Hard: v1.ResourceList{
				v1.ResourcePods: resource.MustParse("1000"),
			},
		},
	}
	waitForQuota(t, quota, clientset)

	startTime = time.Now()
	scale(t, "quotaed", clientset)
	endTime = time.Now()
	t.Logf("Took %v to scale up with quota", endTime.Sub(startTime))
}

func waitForQuota(t *testing.T, quota *v1.ResourceQuota, clientset *clientset.Clientset) {
	w, err := clientset.CoreV1().ResourceQuotas(quota.Namespace).Watch(context.TODO(), metav1.SingleObject(metav1.ObjectMeta{Name: quota.Name}))
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if _, err := clientset.CoreV1().ResourceQuotas(quota.Namespace).Create(context.TODO(), quota, metav1.CreateOptions{}); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 1*time.Minute)
	defer cancel()
	_, err = watchtools.UntilWithoutRetry(ctx, w, func(event watch.Event) (bool, error) {
		switch event.Type {
		case watch.Modified:
		default:
			return false, nil
		}
		switch cast := event.Object.(type) {
		case *v1.ResourceQuota:
			if len(cast.Status.Hard) > 0 {
				return true, nil
			}
		}

		return false, nil
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}

func scale(t *testing.T, namespace string, clientset *clientset.Clientset) {
	target := int32(100)
	rc := &v1.ReplicationController{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "foo",
			Namespace: namespace,
		},
		Spec: v1.ReplicationControllerSpec{
			Replicas: &target,
			Selector: map[string]string{"foo": "bar"},
			Template: &v1.PodTemplateSpec{
				ObjectMeta: metav1.ObjectMeta{
					Labels: map[string]string{
						"foo": "bar",
					},
				},
				Spec: v1.PodSpec{
					Containers: []v1.Container{
						{
							Name:  "container",
							Image: "busybox",
						},
					},
				},
			},
		},
	}

	w, err := clientset.CoreV1().ReplicationControllers(namespace).Watch(context.TODO(), metav1.SingleObject(metav1.ObjectMeta{Name: rc.Name}))
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if _, err := clientset.CoreV1().ReplicationControllers(namespace).Create(context.TODO(), rc, metav1.CreateOptions{}); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
	defer cancel()
	_, err = watchtools.UntilWithoutRetry(ctx, w, func(event watch.Event) (bool, error) {
		switch event.Type {
		case watch.Modified:
		default:
			return false, nil
		}

		switch cast := event.Object.(type) {
		case *v1.ReplicationController:
			fmt.Printf("Found %v of %v replicas\n", int(cast.Status.Replicas), target)
			if cast.Status.Replicas == target {
				return true, nil
			}
		}

		return false, nil
	})
	if err != nil {
		pods, _ := clientset.CoreV1().Pods(namespace).List(context.TODO(), metav1.ListOptions{LabelSelector: labels.Everything().String(), FieldSelector: fields.Everything().String()})
		t.Fatalf("unexpected error: %v, ended with %v pods", err, len(pods.Items))
	}
}

func TestQuotaLimitedResourceDenial(t *testing.T) {
	// Set up a master
	h := &framework.MasterHolder{Initialized: make(chan struct{})}
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		<-h.Initialized
		h.M.GenericAPIServer.Handler.ServeHTTP(w, req)
	}))

	admissionCh := make(chan struct{})
	clientset := clientset.NewForConfigOrDie(&restclient.Config{QPS: -1, Host: s.URL, ContentConfig: restclient.ContentConfig{GroupVersion: &schema.GroupVersion{Group: "", Version: "v1"}}})

	// stop creation of a pod resource unless there is a quota
	config := &resourcequotaapi.Configuration{
		LimitedResources: []resourcequotaapi.LimitedResource{
			{
				Resource:      "pods",
				MatchContains: []string{"pods"},
			},
		},
	}
	qca := quotainstall.NewQuotaConfigurationForAdmission()
	admission, err := resourcequota.NewResourceQuota(config, 5, admissionCh)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	admission.SetExternalKubeClientSet(clientset)
	externalInformers := informers.NewSharedInformerFactory(clientset, controller.NoResyncPeriodFunc())
	admission.SetExternalKubeInformerFactory(externalInformers)
	admission.SetQuotaConfiguration(qca)
	defer close(admissionCh)

	masterConfig := framework.NewIntegrationTestMasterConfig()
	masterConfig.GenericConfig.AdmissionControl = admission
	_, _, closeFn := framework.RunAMasterUsingServer(masterConfig, s, h)
	defer closeFn()

	ns := framework.CreateTestingNamespace("quota", s, t)
	defer framework.DeleteTestingNamespace(ns, s, t)

	controllerCh := make(chan struct{})
	defer close(controllerCh)

	informers := informers.NewSharedInformerFactory(clientset, controller.NoResyncPeriodFunc())
	rm := replicationcontroller.NewReplicationManager(
		informers.Core().V1().Pods(),
		informers.Core().V1().ReplicationControllers(),
		clientset,
		replicationcontroller.BurstReplicas,
	)
	rm.SetEventRecorder(&record.FakeRecorder{})
	go rm.Run(3, controllerCh)

	discoveryFunc := clientset.Discovery().ServerPreferredNamespacedResources
	listerFuncForResource := generic.ListerFuncForResourceFunc(informers.ForResource)
	qc := quotainstall.NewQuotaConfigurationForControllers(listerFuncForResource)
	informersStarted := make(chan struct{})
	resourceQuotaControllerOptions := &resourcequotacontroller.ControllerOptions{
		QuotaClient:               clientset.CoreV1(),
		ResourceQuotaInformer:     informers.Core().V1().ResourceQuotas(),
		ResyncPeriod:              controller.NoResyncPeriodFunc,
		InformerFactory:           informers,
		ReplenishmentResyncPeriod: controller.NoResyncPeriodFunc,
		DiscoveryFunc:             discoveryFunc,
		IgnoredResourcesFunc:      qc.IgnoredResources,
		InformersStarted:          informersStarted,
		Registry:                  generic.NewRegistry(qc.Evaluators()),
	}
	resourceQuotaController, err := resourcequotacontroller.NewController(resourceQuotaControllerOptions)
	if err != nil {
		t.Fatalf("unexpected err: %v", err)
	}
	go resourceQuotaController.Run(2, controllerCh)

	// Periodically the quota controller to detect new resource types
	go resourceQuotaController.Sync(discoveryFunc, 30*time.Second, controllerCh)

	externalInformers.Start(controllerCh)
	informers.Start(controllerCh)
	close(informersStarted)

	// try to create a pod
	pod := &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "foo",
			Namespace: ns.Name,
		},
		Spec: v1.PodSpec{
			Containers: []v1.Container{
				{
					Name:  "container",
					Image: "busybox",
				},
			},
		},
	}
	if _, err := clientset.CoreV1().Pods(ns.Name).Create(context.TODO(), pod, metav1.CreateOptions{}); err == nil {
		t.Fatalf("expected error for insufficient quota")
	}

	// now create a covering quota
	// note: limited resource does a matchContains, so we now have "pods" matching "pods" and "count/pods"
	quota := &v1.ResourceQuota{
		ObjectMeta: metav1.ObjectMeta{
			Name:      "quota",
			Namespace: ns.Name,
		},
		Spec: v1.ResourceQuotaSpec{
			Hard: v1.ResourceList{
				v1.ResourcePods:               resource.MustParse("1000"),
				v1.ResourceName("count/pods"): resource.MustParse("1000"),
			},
		},
	}
	waitForQuota(t, quota, clientset)

	// attempt to create a new pod once the quota is propagated
	err = wait.PollImmediate(5*time.Second, time.Minute, func() (bool, error) {
		// retry until we succeed (to allow time for all changes to propagate)
		if _, err := clientset.CoreV1().Pods(ns.Name).Create(context.TODO(), pod, metav1.CreateOptions{}); err == nil {
			return true, nil
		}
		return false, nil
	})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
}
