plugin_test.go

/*
Copyright 2015 The Kubernetes Authors All rights reserved.

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 scheduler

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"sync"
	"testing"
	"time"

	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/testapi"
	"k8s.io/kubernetes/pkg/api/unversioned"
	"k8s.io/kubernetes/pkg/client/cache"
	client "k8s.io/kubernetes/pkg/client/unversioned"
	"k8s.io/kubernetes/pkg/runtime"
	"k8s.io/kubernetes/pkg/watch"

	log "github.com/golang/glog"
	mesos "github.com/mesos/mesos-go/mesosproto"
	"github.com/mesos/mesos-go/mesosutil"
	bindings "github.com/mesos/mesos-go/scheduler"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	assertext "k8s.io/kubernetes/contrib/mesos/pkg/assert"
	"k8s.io/kubernetes/contrib/mesos/pkg/executor/messages"
	"k8s.io/kubernetes/contrib/mesos/pkg/queue"
	schedcfg "k8s.io/kubernetes/contrib/mesos/pkg/scheduler/config"
	"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/ha"
	"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/meta"
	"k8s.io/kubernetes/contrib/mesos/pkg/scheduler/podtask"
	mresource "k8s.io/kubernetes/contrib/mesos/pkg/scheduler/resource"
	"k8s.io/kubernetes/pkg/util"
)

// A apiserver mock which partially mocks the pods API
type TestServer struct {
	stats map[string]uint
	nodes map[string]*api.Node
	lock  sync.Mutex // guards above fields

	server *httptest.Server
	t      *testing.T
}

func (srv *TestServer) LookupNode(name string) *api.Node {
	srv.lock.Lock()
	defer srv.lock.Unlock()

	node, _ := api.Scheme.DeepCopy(srv.nodes[name])
	return node.(*api.Node)
}

func (srv *TestServer) WaitForNode(name string) {
	assertext.EventuallyTrue(srv.t, util.ForeverTestTimeout, func() bool {
		return srv.LookupNode(name) != nil
	})
}

func NewTestServer(t *testing.T, namespace string, mockPodListWatch *MockPodsListWatch) *TestServer {
	ts := TestServer{
		stats: map[string]uint{},
		nodes: map[string]*api.Node{},
		t:     t,
	}
	mux := http.NewServeMux()

	podListHandler := func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		pods := mockPodListWatch.Pods()
		w.Write([]byte(runtime.EncodeOrDie(testapi.Default.Codec(), &pods)))
	}
	mux.HandleFunc(testapi.Default.ResourcePath("pods", namespace, ""), podListHandler)
	mux.HandleFunc(testapi.Default.ResourcePath("pods", "", ""), podListHandler)

	podsPrefix := testapi.Default.ResourcePath("pods", namespace, "") + "/"
	mux.HandleFunc(podsPrefix, func(w http.ResponseWriter, r *http.Request) {
		name := r.URL.Path[len(podsPrefix):]

		// update statistics for this pod
		ts.lock.Lock()
		defer ts.lock.Unlock()
		ts.stats[name] = ts.stats[name] + 1

		p := mockPodListWatch.Pod(name)
		if p != nil {
			w.WriteHeader(http.StatusOK)
			w.Write([]byte(runtime.EncodeOrDie(testapi.Default.Codec(), p)))
			return
		}
		w.WriteHeader(http.StatusNotFound)
	})

	mux.HandleFunc(
		testapi.Default.ResourcePath("events", namespace, ""),
		func(w http.ResponseWriter, r *http.Request) {
			w.WriteHeader(http.StatusOK)
		},
	)

	mux.HandleFunc(
		testapi.Default.ResourcePath("nodes", "", ""),
		func(w http.ResponseWriter, r *http.Request) {
			var node api.Node
			if err := json.NewDecoder(r.Body).Decode(&node); err != nil {
				w.WriteHeader(http.StatusInternalServerError)
				return
			}

			ts.lock.Lock()
			defer ts.lock.Unlock()
			ts.nodes[node.Name] = &node

			if err := json.NewEncoder(w).Encode(node); err != nil {
				w.WriteHeader(http.StatusInternalServerError)
				return
			}
			w.WriteHeader(http.StatusOK)
		},
	)

	mux.HandleFunc("/", func(res http.ResponseWriter, req *http.Request) {
		t.Errorf("unexpected request: %v", req.RequestURI)
		res.WriteHeader(http.StatusNotFound)
	})

	ts.server = httptest.NewServer(mux)
	return &ts
}

func (ts *TestServer) Stats(name string) uint {
	ts.lock.Lock()
	defer ts.lock.Unlock()

	return ts.stats[name]
}

// Create mock of pods ListWatch, usually listening on the apiserver pods watch endpoint
type MockPodsListWatch struct {
	ListWatch   cache.ListWatch
	fakeWatcher *watch.FakeWatcher
	list        api.PodList
	lock        sync.Mutex
}

func NewMockPodsListWatch(initialPodList api.PodList) *MockPodsListWatch {
	lw := MockPodsListWatch{
		fakeWatcher: watch.NewFake(),
		list:        initialPodList,
	}
	lw.ListWatch = cache.ListWatch{
		WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
			return lw.fakeWatcher, nil
		},
		ListFunc: func() (runtime.Object, error) {
			lw.lock.Lock()
			defer lw.lock.Unlock()

			listCopy, err := api.Scheme.DeepCopy(&lw.list)
			return listCopy.(*api.PodList), err
		},
	}
	return &lw
}

func (lw *MockPodsListWatch) Pods() api.PodList {
	lw.lock.Lock()
	defer lw.lock.Unlock()

	obj, _ := api.Scheme.DeepCopy(&lw.list)
	return *(obj.(*api.PodList))
}

func (lw *MockPodsListWatch) Pod(name string) *api.Pod {
	lw.lock.Lock()
	defer lw.lock.Unlock()

	for _, p := range lw.list.Items {
		if p.Name == name {
			return &p
		}
	}

	return nil
}
func (lw *MockPodsListWatch) Add(pod *api.Pod, notify bool) {
	func() {
		lw.lock.Lock()
		defer lw.lock.Unlock()
		lw.list.Items = append(lw.list.Items, *pod)
	}()

	if notify {
		lw.fakeWatcher.Add(pod)
	}
}
func (lw *MockPodsListWatch) Modify(pod *api.Pod, notify bool) {
	found := false
	func() {
		lw.lock.Lock()
		defer lw.lock.Unlock()

		for i, otherPod := range lw.list.Items {
			if otherPod.Name == pod.Name {
				lw.list.Items[i] = *pod
				found = true
				return
			}
		}
		log.Fatalf("Cannot find pod %v to modify in MockPodsListWatch", pod.Name)
	}()

	if notify && found {
		lw.fakeWatcher.Modify(pod)
	}
}

func (lw *MockPodsListWatch) Delete(pod *api.Pod, notify bool) {
	var notifyPod *api.Pod
	func() {
		lw.lock.Lock()
		defer lw.lock.Unlock()

		for i, otherPod := range lw.list.Items {
			if otherPod.Name == pod.Name {
				lw.list.Items = append(lw.list.Items[:i], lw.list.Items[i+1:]...)
				notifyPod = &otherPod
				return
			}
		}
		log.Fatalf("Cannot find pod %v to delete in MockPodsListWatch", pod.Name)
	}()

	if notifyPod != nil && notify {
		lw.fakeWatcher.Delete(notifyPod)
	}
}

// Create a pod with a given index, requiring one port
var currentPodNum int = 0

func NewTestPod() (*api.Pod, int) {
	currentPodNum = currentPodNum + 1
	name := fmt.Sprintf("pod%d", currentPodNum)
	return &api.Pod{
		TypeMeta: unversioned.TypeMeta{APIVersion: testapi.Default.Version()},
		ObjectMeta: api.ObjectMeta{
			Name:      name,
			Namespace: api.NamespaceDefault,
			SelfLink:  fmt.Sprintf("http://1.2.3.4/api/v1beta1/pods/%s", name),
		},
		Spec: api.PodSpec{
			Containers: []api.Container{
				{
					Ports: []api.ContainerPort{
						{
							ContainerPort: 8000 + currentPodNum,
							Protocol:      api.ProtocolTCP,
						},
					},
				},
			},
		},
		Status: api.PodStatus{
			PodIP: fmt.Sprintf("1.2.3.%d", 4+currentPodNum),
			Conditions: []api.PodCondition{
				{
					Type:   api.PodReady,
					Status: api.ConditionTrue,
				},
			},
		},
	}, currentPodNum
}

// Offering some cpus and memory and the 8000-9000 port range
func NewTestOffer(id string) *mesos.Offer {
	hostname := "some_hostname"
	cpus := mesosutil.NewScalarResource("cpus", 3.75)
	mem := mesosutil.NewScalarResource("mem", 940)
	var port8000 uint64 = 8000
	var port9000 uint64 = 9000
	ports8000to9000 := mesos.Value_Range{Begin: &port8000, End: &port9000}
	ports := mesosutil.NewRangesResource("ports", []*mesos.Value_Range{&ports8000to9000})
	return &mesos.Offer{
		Id:        mesosutil.NewOfferID(id),
		Hostname:  &hostname,
		SlaveId:   mesosutil.NewSlaveID(hostname),
		Resources: []*mesos.Resource{cpus, mem, ports},
	}
}

// Add assertions to reason about event streams
type Event struct {
	Object  runtime.Object
	Reason  string
	Message string
}

type EventPredicate func(e Event) bool

type EventAssertions struct {
	assert.Assertions
}

// EventObserver implements record.EventRecorder for the purposes of validation via EventAssertions.
type EventObserver struct {
	fifo chan Event
}

func NewEventObserver() *EventObserver {
	return &EventObserver{
		fifo: make(chan Event, 1000),
	}
}

func (o *EventObserver) Event(object runtime.Object, reason, message string) {
	o.fifo <- Event{Object: object, Reason: reason, Message: message}
}

func (o *EventObserver) Eventf(object runtime.Object, reason, messageFmt string, args ...interface{}) {
	o.fifo <- Event{Object: object, Reason: reason, Message: fmt.Sprintf(messageFmt, args...)}
}
func (o *EventObserver) PastEventf(object runtime.Object, timestamp unversioned.Time, reason, messageFmt string, args ...interface{}) {
	o.fifo <- Event{Object: object, Reason: reason, Message: fmt.Sprintf(messageFmt, args...)}
}

func (a *EventAssertions) Event(observer *EventObserver, pred EventPredicate, msgAndArgs ...interface{}) bool {
	// parse msgAndArgs: first possibly a duration, otherwise a format string with further args
	timeout := util.ForeverTestTimeout
	msg := "event not received"
	msgArgStart := 0
	if len(msgAndArgs) > 0 {
		switch msgAndArgs[0].(type) {
		case time.Duration:
			timeout = msgAndArgs[0].(time.Duration)
			msgArgStart += 1
		}
	}
	if len(msgAndArgs) > msgArgStart {
		msg = fmt.Sprintf(msgAndArgs[msgArgStart].(string), msgAndArgs[msgArgStart+1:]...)
	}

	// watch events
	result := make(chan bool)
	stop := make(chan struct{})
	go func() {
		for {
			select {
			case e, ok := <-observer.fifo:
				if !ok {
					result <- false
					return
				} else if pred(e) {
					log.V(3).Infof("found asserted event for reason '%v': %v", e.Reason, e.Message)
					result <- true
					return
				} else {
					log.V(5).Infof("ignoring not-asserted event for reason '%v': %v", e.Reason, e.Message)
				}
			case _, ok := <-stop:
				if !ok {
					return
				}
			}
		}
	}()
	defer close(stop)

	// wait for watch to match or timeout
	select {
	case matched := <-result:
		return matched
	case <-time.After(timeout):
		return a.Fail(msg)
	}
}

func (a *EventAssertions) EventWithReason(observer *EventObserver, reason string, msgAndArgs ...interface{}) bool {
	return a.Event(observer, func(e Event) bool {
		return e.Reason == reason
	}, msgAndArgs...)
}

type joinableDriver struct {
	MockSchedulerDriver
	joinFunc func() (mesos.Status, error)
}

// Join invokes joinFunc if it has been set, otherwise blocks forever
func (m *joinableDriver) Join() (mesos.Status, error) {
	if m.joinFunc != nil {
		return m.joinFunc()
	}
	select {}
}

// Create mesos.TaskStatus for a given task
func newTaskStatusForTask(task *mesos.TaskInfo, state mesos.TaskState) *mesos.TaskStatus {
	healthy := state == mesos.TaskState_TASK_RUNNING
	ts := float64(time.Now().Nanosecond()) / 1000000000.0
	source := mesos.TaskStatus_SOURCE_EXECUTOR
	return &mesos.TaskStatus{
		TaskId:     task.TaskId,
		State:      &state,
		SlaveId:    task.SlaveId,
		ExecutorId: task.Executor.ExecutorId,
		Timestamp:  &ts,
		Healthy:    &healthy,
		Source:     &source,
		Data:       task.Data,
	}
}

type LaunchedTask struct {
	offerId  mesos.OfferID
	taskInfo *mesos.TaskInfo
}

type lifecycleTest struct {
	apiServer     *TestServer
	driver        *joinableDriver
	eventObs      *EventObserver
	plugin        *schedulingPlugin
	podsListWatch *MockPodsListWatch
	scheduler     *KubernetesScheduler
	schedulerProc *ha.SchedulerProcess
	t             *testing.T
}

func newLifecycleTest(t *testing.T) lifecycleTest {
	assert := &EventAssertions{*assert.New(t)}

	// create a fake pod watch. We use that below to submit new pods to the scheduler
	podsListWatch := NewMockPodsListWatch(api.PodList{})

	// create fake apiserver
	apiServer := NewTestServer(t, api.NamespaceDefault, podsListWatch)

	// create executor with some data for static pods if set
	executor := mesosutil.NewExecutorInfo(
		mesosutil.NewExecutorID("executor-id"),
		mesosutil.NewCommandInfo("executor-cmd"),
	)
	executor.Data = []byte{0, 1, 2}

	// create scheduler
	strategy := NewAllocationStrategy(
		podtask.NewDefaultPredicate(
			mresource.DefaultDefaultContainerCPULimit,
			mresource.DefaultDefaultContainerMemLimit,
		),
		podtask.NewDefaultProcurement(
			mresource.DefaultDefaultContainerCPULimit,
			mresource.DefaultDefaultContainerMemLimit,
		),
	)

	scheduler := New(Config{
		Executor: executor,
		Client: client.NewOrDie(&client.Config{
			Host:    apiServer.server.URL,
			Version: testapi.Default.Version(),
		}),
		Scheduler:  NewFCFSPodScheduler(strategy, apiServer.LookupNode),
		Schedcfg:   *schedcfg.CreateDefaultConfig(),
		LookupNode: apiServer.LookupNode,
	})

	assert.NotNil(scheduler.client, "client is nil")
	assert.NotNil(scheduler.executor, "executor is nil")
	assert.NotNil(scheduler.offers, "offer registry is nil")

	// create scheduler process
	schedulerProc := ha.New(scheduler)

	// get plugin config from it
	config := scheduler.NewPluginConfig(
		schedulerProc.Terminal(),
		http.DefaultServeMux,
		&podsListWatch.ListWatch,
	)
	assert.NotNil(config)

	// make events observable
	eventObs := NewEventObserver()
	config.Recorder = eventObs

	// create plugin
	plugin := NewPlugin(config).(*schedulingPlugin)
	assert.NotNil(plugin)

	// create mock mesos scheduler driver
	driver := &joinableDriver{}

	return lifecycleTest{
		apiServer:     apiServer,
		driver:        driver,
		eventObs:      eventObs,
		plugin:        plugin,
		podsListWatch: podsListWatch,
		scheduler:     scheduler,
		schedulerProc: schedulerProc,
		t:             t,
	}
}

func (lt lifecycleTest) Start() <-chan LaunchedTask {
	assert := &EventAssertions{*assert.New(lt.t)}
	lt.plugin.Run(lt.schedulerProc.Terminal())

	// init scheduler
	err := lt.scheduler.Init(
		lt.schedulerProc.Master(),
		lt.plugin,
		http.DefaultServeMux,
	)
	assert.NoError(err)

	lt.driver.On("Start").Return(mesos.Status_DRIVER_RUNNING, nil).Once()
	started := lt.driver.Upon()

	lt.driver.On("ReconcileTasks",
		mock.AnythingOfType("[]*mesosproto.TaskStatus"),
	).Return(mesos.Status_DRIVER_RUNNING, nil)

	lt.driver.On("SendFrameworkMessage",
		mock.AnythingOfType("*mesosproto.ExecutorID"),
		mock.AnythingOfType("*mesosproto.SlaveID"),
		mock.AnythingOfType("string"),
	).Return(mesos.Status_DRIVER_RUNNING, nil)

	launchedTasks := make(chan LaunchedTask, 1)
	launchTasksFunc := func(args mock.Arguments) {
		offerIDs := args.Get(0).([]*mesos.OfferID)
		taskInfos := args.Get(1).([]*mesos.TaskInfo)
		assert.Equal(1, len(offerIDs))
		assert.Equal(1, len(taskInfos))

		launchedTasks <- LaunchedTask{
			offerId:  *offerIDs[0],
			taskInfo: taskInfos[0],
		}
	}

	lt.driver.On("LaunchTasks",
		mock.AnythingOfType("[]*mesosproto.OfferID"),
		mock.AnythingOfType("[]*mesosproto.TaskInfo"),
		mock.AnythingOfType("*mesosproto.Filters"),
	).Return(mesos.Status_DRIVER_RUNNING, nil).Run(launchTasksFunc)

	lt.driver.On("DeclineOffer",
		mock.AnythingOfType("*mesosproto.OfferID"),
		mock.AnythingOfType("*mesosproto.Filters"),
	).Return(mesos.Status_DRIVER_RUNNING, nil)

	// elect master with mock driver
	driverFactory := ha.DriverFactory(func() (bindings.SchedulerDriver, error) {
		return lt.driver, nil
	})
	lt.schedulerProc.Elect(driverFactory)
	elected := lt.schedulerProc.Elected()

	// driver will be started
	<-started

	// tell scheduler to be registered
	lt.scheduler.Registered(
		lt.driver,
		mesosutil.NewFrameworkID("kubernetes-id"),
		mesosutil.NewMasterInfo("master-id", (192<<24)+(168<<16)+(0<<8)+1, 5050),
	)

	// wait for being elected
	<-elected
	return launchedTasks
}

func (lt lifecycleTest) Close() {
	lt.apiServer.server.Close()
}

func (lt lifecycleTest) End() <-chan struct{} {
	return lt.schedulerProc.End()
}

// Test to create the scheduler plugin with an empty plugin config
func TestPlugin_New(t *testing.T) {
	assert := assert.New(t)

	c := PluginConfig{}
	p := NewPlugin(&c)
	assert.NotNil(p)
}

// TestPlugin_LifeCycle creates a scheduler plugin with the config returned by the scheduler,
// and plays through the whole life cycle of the plugin while creating pods, deleting
// and failing them.
func TestPlugin_LifeCycle(t *testing.T) {
	assert := &EventAssertions{*assert.New(t)}
	lt := newLifecycleTest(t)
	defer lt.Close()

	// run plugin
	launchedTasks := lt.Start()
	defer lt.End()

	// fake new, unscheduled pod
	pod, i := NewTestPod()
	lt.podsListWatch.Add(pod, true) // notify watchers

	// wait for failedScheduling event because there is no offer
	assert.EventWithReason(lt.eventObs, FailedScheduling, "failedScheduling event not received")

	// add some matching offer
	offers := []*mesos.Offer{NewTestOffer(fmt.Sprintf("offer%d", i))}
	lt.scheduler.ResourceOffers(nil, offers)

	// first offer is declined because node is not available yet
	lt.apiServer.WaitForNode("some_hostname")

	// add one more offer
	lt.scheduler.ResourceOffers(nil, offers)

	// and wait for scheduled pod
	assert.EventWithReason(lt.eventObs, Scheduled)
	select {
	case launchedTask := <-launchedTasks:
		// report back that the task has been staged, and then started by mesos
		lt.scheduler.StatusUpdate(
			lt.driver,
			newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_STAGING),
		)

		lt.scheduler.StatusUpdate(
			lt.driver,
			newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_RUNNING),
		)

		// check that ExecutorInfo.data has the static pod data
		assert.Len(launchedTask.taskInfo.Executor.Data, 3)

		// report back that the task has been lost
		lt.driver.AssertNumberOfCalls(t, "SendFrameworkMessage", 0)

		lt.scheduler.StatusUpdate(
			lt.driver,
			newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_LOST),
		)

		// and wait that framework message is sent to executor
		lt.driver.AssertNumberOfCalls(t, "SendFrameworkMessage", 1)

	case <-time.After(util.ForeverTestTimeout):
		t.Fatalf("timed out waiting for launchTasks call")
	}

	offeredNodes := make(map[string]struct{})

	// Launch a pod and wait until the scheduler driver is called
	schedulePodWithOffers := func(pod *api.Pod, offers []*mesos.Offer) (*api.Pod, *LaunchedTask, *mesos.Offer) {
		// wait for failedScheduling event because there is no offer
		assert.EventWithReason(lt.eventObs, FailedScheduling, "failedScheduling event not received")

		// supply a matching offer
		lt.scheduler.ResourceOffers(lt.driver, offers)
		for _, offer := range offers {
			if _, ok := offeredNodes[offer.GetHostname()]; !ok {
				offeredNodes[offer.GetHostname()] = struct{}{}
				lt.apiServer.WaitForNode(offer.GetHostname())

				// reoffer since it must have been declined above
				lt.scheduler.ResourceOffers(lt.driver, []*mesos.Offer{offer})
			}
		}

		// and wait to get scheduled
		assert.EventWithReason(lt.eventObs, Scheduled)

		// wait for driver.launchTasks call
		select {
		case launchedTask := <-launchedTasks:
			for _, offer := range offers {
				if offer.Id.GetValue() == launchedTask.offerId.GetValue() {
					return pod, &launchedTask, offer
				}
			}
			t.Fatalf("unknown offer used to start a pod")
			return nil, nil, nil
		case <-time.After(util.ForeverTestTimeout):
			t.Fatal("timed out waiting for launchTasks")
			return nil, nil, nil
		}
	}

	// Launch a pod and wait until the scheduler driver is called
	launchPodWithOffers := func(pod *api.Pod, offers []*mesos.Offer) (*api.Pod, *LaunchedTask, *mesos.Offer) {
		lt.podsListWatch.Add(pod, true)
		return schedulePodWithOffers(pod, offers)
	}

	// Launch a pod, wait until the scheduler driver is called and report back that it is running
	startPodWithOffers := func(pod *api.Pod, offers []*mesos.Offer) (*api.Pod, *LaunchedTask, *mesos.Offer) {
		// notify about pod, offer resources and wait for scheduling
		pod, launchedTask, offer := launchPodWithOffers(pod, offers)
		if pod != nil {
			// report back status
			lt.scheduler.StatusUpdate(
				lt.driver,
				newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_STAGING),
			)
			lt.scheduler.StatusUpdate(
				lt.driver,
				newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_RUNNING),
			)

			return pod, launchedTask, offer
		}

		return nil, nil, nil
	}

	startTestPod := func() (*api.Pod, *LaunchedTask, *mesos.Offer) {
		pod, i := NewTestPod()
		offers := []*mesos.Offer{NewTestOffer(fmt.Sprintf("offer%d", i))}
		return startPodWithOffers(pod, offers)
	}

	// start another pod
	pod, launchedTask, _ := startTestPod()

	// mock driver.KillTask, should be invoked when a pod is deleted
	lt.driver.On("KillTask",
		mock.AnythingOfType("*mesosproto.TaskID"),
	).Return(mesos.Status_DRIVER_RUNNING, nil).Run(func(args mock.Arguments) {
		killedTaskId := *(args.Get(0).(*mesos.TaskID))
		assert.Equal(*launchedTask.taskInfo.TaskId, killedTaskId, "expected same TaskID as during launch")
	})
	killTaskCalled := lt.driver.Upon()

	// stop it again via the apiserver mock
	lt.podsListWatch.Delete(pod, true) // notify watchers

	// and wait for the driver killTask call with the correct TaskId
	select {
	case <-killTaskCalled:
		// report back that the task is finished
		lt.scheduler.StatusUpdate(
			lt.driver,
			newTaskStatusForTask(launchedTask.taskInfo, mesos.TaskState_TASK_FINISHED),
		)

	case <-time.After(util.ForeverTestTimeout):
		t.Fatal("timed out waiting for KillTask")
	}

	// start a pod with on a given NodeName and check that it is scheduled to the right host
	pod, i = NewTestPod()
	pod.Spec.NodeName = "hostname1"
	offers = []*mesos.Offer{}
	for j := 0; j < 3; j++ {
		offer := NewTestOffer(fmt.Sprintf("offer%d_%d", i, j))
		hostname := fmt.Sprintf("hostname%d", j)
		offer.Hostname = &hostname
		offers = append(offers, offer)
	}

	_, _, usedOffer := startPodWithOffers(pod, offers)

	assert.Equal(offers[1].Id.GetValue(), usedOffer.Id.GetValue())
	assert.Equal(pod.Spec.NodeName, *usedOffer.Hostname)

	lt.scheduler.OfferRescinded(lt.driver, offers[0].Id)
	lt.scheduler.OfferRescinded(lt.driver, offers[2].Id)

	// start pods:
	// - which are failing while binding,
	// - leading to reconciliation
	// - with different states on the apiserver

	failPodFromExecutor := func(task *mesos.TaskInfo) {
		beforePodLookups := lt.apiServer.Stats(pod.Name)
		status := newTaskStatusForTask(task, mesos.TaskState_TASK_FAILED)
		message := messages.CreateBindingFailure
		status.Message = &message
		lt.scheduler.StatusUpdate(lt.driver, status)

		// wait until pod is looked up at the apiserver
		assertext.EventuallyTrue(t, util.ForeverTestTimeout, func() bool {
			return lt.apiServer.Stats(pod.Name) == beforePodLookups+1
		}, "expect that reconcileTask will access apiserver for pod %v", pod.Name)
	}

	launchTestPod := func() (*api.Pod, *LaunchedTask, *mesos.Offer) {
		pod, i := NewTestPod()
		offers := []*mesos.Offer{NewTestOffer(fmt.Sprintf("offer%d", i))}
		return launchPodWithOffers(pod, offers)
	}

	// 1. with pod deleted from the apiserver
	//    expected: pod is removed from internal task registry
	pod, launchedTask, _ = launchTestPod()
	lt.podsListWatch.Delete(pod, false) // not notifying the watchers
	failPodFromExecutor(launchedTask.taskInfo)

	podKey, _ := podtask.MakePodKey(api.NewDefaultContext(), pod.Name)
	assertext.EventuallyTrue(t, util.ForeverTestTimeout, func() bool {
		t, _ := lt.plugin.api.tasks().ForPod(podKey)
		return t == nil
	})

	// 2. with pod still on the apiserver, not bound
	//    expected: pod is rescheduled
	pod, launchedTask, _ = launchTestPod()
	failPodFromExecutor(launchedTask.taskInfo)

	retryOffers := []*mesos.Offer{NewTestOffer("retry-offer")}
	schedulePodWithOffers(pod, retryOffers)

	// 3. with pod still on the apiserver, bound, notified via ListWatch
	// expected: nothing, pod updates not supported, compare ReconcileTask function
	pod, launchedTask, usedOffer = startTestPod()
	pod.Annotations = map[string]string{
		meta.BindingHostKey: *usedOffer.Hostname,
	}
	pod.Spec.NodeName = *usedOffer.Hostname
	lt.podsListWatch.Modify(pod, true) // notifying the watchers
	time.Sleep(time.Second / 2)
	failPodFromExecutor(launchedTask.taskInfo)
}

func TestDeleteOne_NonexistentPod(t *testing.T) {
	assert := assert.New(t)
	obj := &MockScheduler{}
	reg := podtask.NewInMemoryRegistry()
	obj.On("tasks").Return(reg)

	qr := newQueuer(nil)
	assert.Equal(0, len(qr.podQueue.List()))
	d := &deleter{
		api: obj,
		qr:  qr,
	}
	pod := &Pod{Pod: &api.Pod{
		ObjectMeta: api.ObjectMeta{
			Name:      "foo",
			Namespace: api.NamespaceDefault,
		}}}
	err := d.deleteOne(pod)
	assert.Equal(err, noSuchPodErr)
	obj.AssertExpectations(t)
}

func TestDeleteOne_PendingPod(t *testing.T) {
	assert := assert.New(t)
	obj := &MockScheduler{}
	reg := podtask.NewInMemoryRegistry()
	obj.On("tasks").Return(reg)

	pod := &Pod{Pod: &api.Pod{
		ObjectMeta: api.ObjectMeta{
			Name:      "foo",
			UID:       "foo0",
			Namespace: api.NamespaceDefault,
		}}}

	task, err := podtask.New(api.NewDefaultContext(), "bar", *pod.Pod, &mesos.ExecutorInfo{})
	if err != nil {
		t.Fatalf("failed to create task: %v", err)
	}

	_, err = reg.Register(task)
	if err != nil {
		t.Fatalf("failed to register task: %v", err)
	}

	// preconditions
	qr := newQueuer(nil)
	qr.podQueue.Add(pod, queue.ReplaceExisting)
	assert.Equal(1, len(qr.podQueue.List()))
	_, found := qr.podQueue.Get("default/foo")
	assert.True(found)

	// exec & post conditions
	d := &deleter{
		api: obj,
		qr:  qr,
	}
	err = d.deleteOne(pod)
	assert.Nil(err)
	_, found = qr.podQueue.Get("foo0")
	assert.False(found)
	assert.Equal(0, len(qr.podQueue.List()))
	obj.AssertExpectations(t)
}

func TestDeleteOne_Running(t *testing.T) {
	assert := assert.New(t)
	obj := &MockScheduler{}
	reg := podtask.NewInMemoryRegistry()
	obj.On("tasks").Return(reg)

	pod := &Pod{Pod: &api.Pod{
		ObjectMeta: api.ObjectMeta{
			Name:      "foo",
			UID:       "foo0",
			Namespace: api.NamespaceDefault,
		}}}

	task, err := podtask.New(api.NewDefaultContext(), "bar", *pod.Pod, &mesos.ExecutorInfo{})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	task, err = reg.Register(task)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	task.Set(podtask.Launched)
	err = reg.Update(task)
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	// preconditions
	qr := newQueuer(nil)
	qr.podQueue.Add(pod, queue.ReplaceExisting)
	assert.Equal(1, len(qr.podQueue.List()))
	_, found := qr.podQueue.Get("default/foo")
	assert.True(found)

	obj.On("killTask", task.ID).Return(nil)

	// exec & post conditions
	d := &deleter{
		api: obj,
		qr:  qr,
	}
	err = d.deleteOne(pod)
	assert.Nil(err)
	_, found = qr.podQueue.Get("foo0")
	assert.False(found)
	assert.Equal(0, len(qr.podQueue.List()))
	obj.AssertExpectations(t)
}

func TestDeleteOne_badPodNaming(t *testing.T) {
	assert := assert.New(t)
	obj := &MockScheduler{}
	pod := &Pod{Pod: &api.Pod{}}
	d := &deleter{
		api: obj,
		qr:  newQueuer(nil),
	}

	err := d.deleteOne(pod)
	assert.NotNil(err)

	pod.Pod.ObjectMeta.Name = "foo"
	err = d.deleteOne(pod)
	assert.NotNil(err)

	pod.Pod.ObjectMeta.Name = ""
	pod.Pod.ObjectMeta.Namespace = "bar"
	err = d.deleteOne(pod)
	assert.NotNil(err)

	obj.AssertExpectations(t)
}