k3s/pkg/kubelet/pleg/generic_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 pleg

import (
	"fmt"
	"reflect"
	"sort"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
	"k8s.io/kubernetes/pkg/types"
	"k8s.io/kubernetes/pkg/util"
)

const (
	testContainerRuntimeType = "fooRuntime"
)

type TestGenericPLEG struct {
	pleg    *GenericPLEG
	runtime *kubecontainer.FakeRuntime
}

func newTestGenericPLEG() *TestGenericPLEG {
	fakeRuntime := &kubecontainer.FakeRuntime{}
	// The channel capacity should be large enough to hold all events in a
	// single test.
	pleg := &GenericPLEG{
		relistPeriod: time.Hour,
		runtime:      fakeRuntime,
		eventChannel: make(chan *PodLifecycleEvent, 100),
		podRecords:   make(podRecords),
	}
	return &TestGenericPLEG{pleg: pleg, runtime: fakeRuntime}
}

func getEventsFromChannel(ch <-chan *PodLifecycleEvent) []*PodLifecycleEvent {
	events := []*PodLifecycleEvent{}
	for len(ch) > 0 {
		e := <-ch
		events = append(events, e)
	}
	return events
}

func createTestContainer(ID string, state kubecontainer.ContainerState) *kubecontainer.Container {
	return &kubecontainer.Container{
		ID:    kubecontainer.ContainerID{Type: testContainerRuntimeType, ID: ID},
		State: state,
	}
}

type sortableEvents []*PodLifecycleEvent

func (a sortableEvents) Len() int      { return len(a) }
func (a sortableEvents) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a sortableEvents) Less(i, j int) bool {
	if a[i].ID != a[j].ID {
		return a[i].ID < a[j].ID
	}
	return a[i].Data.(string) < a[j].Data.(string)
}

func verifyEvents(t *testing.T, expected, actual []*PodLifecycleEvent) {
	sort.Sort(sortableEvents(expected))
	sort.Sort(sortableEvents(actual))
	if !reflect.DeepEqual(expected, actual) {
		t.Errorf("Actual events differ from the expected; diff:\n %v", util.ObjectDiff(expected, actual))
	}
}

func TestRelisting(t *testing.T) {
	testPleg := newTestGenericPLEG()
	pleg, runtime := testPleg.pleg, testPleg.runtime
	ch := pleg.Watch()
	// The first relist should send a PodSync event to each pod.
	runtime.AllPodList = []*kubecontainer.Pod{
		{
			ID: "1234",
			Containers: []*kubecontainer.Container{
				createTestContainer("c1", kubecontainer.ContainerStateExited),
				createTestContainer("c2", kubecontainer.ContainerStateRunning),
				createTestContainer("c3", kubecontainer.ContainerStateUnknown),
			},
		},
		{
			ID: "4567",
			Containers: []*kubecontainer.Container{
				createTestContainer("c1", kubecontainer.ContainerStateExited),
			},
		},
	}
	pleg.relist()
	// Report every running/exited container if we see them for the first time.
	expected := []*PodLifecycleEvent{
		{ID: "1234", Type: ContainerStarted, Data: "c2"},
		{ID: "4567", Type: ContainerDied, Data: "c1"},
		{ID: "1234", Type: ContainerDied, Data: "c1"},
	}
	actual := getEventsFromChannel(ch)
	verifyEvents(t, expected, actual)

	// The second relist should not send out any event because no container
	// changed.
	pleg.relist()
	verifyEvents(t, expected, actual)

	runtime.AllPodList = []*kubecontainer.Pod{
		{
			ID: "1234",
			Containers: []*kubecontainer.Container{
				createTestContainer("c2", kubecontainer.ContainerStateExited),
				createTestContainer("c3", kubecontainer.ContainerStateRunning),
			},
		},
		{
			ID: "4567",
			Containers: []*kubecontainer.Container{
				createTestContainer("c4", kubecontainer.ContainerStateRunning),
			},
		},
	}
	pleg.relist()
	// Only report containers that transitioned to running or exited status.
	expected = []*PodLifecycleEvent{
		{ID: "1234", Type: ContainerDied, Data: "c2"},
		{ID: "1234", Type: ContainerStarted, Data: "c3"},
		{ID: "4567", Type: ContainerStarted, Data: "c4"},
	}

	actual = getEventsFromChannel(ch)
	verifyEvents(t, expected, actual)
}

func TestReportMissingContainers(t *testing.T) {
	testPleg := newTestGenericPLEG()
	pleg, runtime := testPleg.pleg, testPleg.runtime
	ch := pleg.Watch()
	runtime.AllPodList = []*kubecontainer.Pod{
		{
			ID: "1234",
			Containers: []*kubecontainer.Container{
				createTestContainer("c1", kubecontainer.ContainerStateRunning),
				createTestContainer("c2", kubecontainer.ContainerStateRunning),
				createTestContainer("c3", kubecontainer.ContainerStateExited),
			},
		},
	}
	// Drain the events from the channel
	pleg.relist()
	getEventsFromChannel(ch)

	// Container c2 was stopped and removed between relists. We should report
	// the event. The exited container c3 was garbage collected (i.e., removed)
	// between relists. We should ignore that event.
	runtime.AllPodList = []*kubecontainer.Pod{
		{
			ID: "1234",
			Containers: []*kubecontainer.Container{
				createTestContainer("c1", kubecontainer.ContainerStateRunning),
			},
		},
	}
	pleg.relist()
	expected := []*PodLifecycleEvent{
		{ID: "1234", Type: ContainerDied, Data: "c2"},
	}
	actual := getEventsFromChannel(ch)
	verifyEvents(t, expected, actual)
}

func TestReportMissingPods(t *testing.T) {
	testPleg := newTestGenericPLEG()
	pleg, runtime := testPleg.pleg, testPleg.runtime
	ch := pleg.Watch()
	runtime.AllPodList = []*kubecontainer.Pod{
		{
			ID: "1234",
			Containers: []*kubecontainer.Container{
				createTestContainer("c2", kubecontainer.ContainerStateRunning),
			},
		},
	}
	// Drain the events from the channel
	pleg.relist()
	getEventsFromChannel(ch)

	// Container c2 was stopped and removed between relists. We should report
	// the event.
	runtime.AllPodList = []*kubecontainer.Pod{}
	pleg.relist()
	expected := []*PodLifecycleEvent{
		{ID: "1234", Type: ContainerDied, Data: "c2"},
	}
	actual := getEventsFromChannel(ch)
	verifyEvents(t, expected, actual)
}

func newTestGenericPLEGWithRuntimeMock() (*GenericPLEG, *kubecontainer.Mock) {
	runtimeMock := &kubecontainer.Mock{}
	pleg := &GenericPLEG{
		relistPeriod: time.Hour,
		runtime:      runtimeMock,
		eventChannel: make(chan *PodLifecycleEvent, 100),
		podRecords:   make(podRecords),
		cache:        kubecontainer.NewCache(),
	}
	return pleg, runtimeMock
}

func createTestPodsStatusesAndEvents(num int) ([]*kubecontainer.Pod, []*kubecontainer.PodStatus, []*PodLifecycleEvent) {
	var pods []*kubecontainer.Pod
	var statuses []*kubecontainer.PodStatus
	var events []*PodLifecycleEvent
	for i := 0; i < num; i++ {
		id := types.UID(fmt.Sprintf("test-pod-%d", i))
		cState := kubecontainer.ContainerStateRunning
		container := createTestContainer(fmt.Sprintf("c%d", i), cState)
		pod := &kubecontainer.Pod{
			ID:         id,
			Containers: []*kubecontainer.Container{container},
		}
		status := &kubecontainer.PodStatus{
			ID:                id,
			ContainerStatuses: []*kubecontainer.ContainerStatus{{ID: container.ID, State: cState}},
		}
		event := &PodLifecycleEvent{ID: pod.ID, Type: ContainerStarted, Data: container.ID.ID}
		pods = append(pods, pod)
		statuses = append(statuses, status)
		events = append(events, event)

	}
	return pods, statuses, events
}

func TestRelistWithCache(t *testing.T) {
	pleg, runtimeMock := newTestGenericPLEGWithRuntimeMock()
	ch := pleg.Watch()

	pods, statuses, events := createTestPodsStatusesAndEvents(2)
	runtimeMock.On("GetPods", true).Return(pods, nil)
	runtimeMock.On("GetPodStatus", pods[0].ID, "", "").Return(statuses[0], nil).Once()
	// Inject an error when querying runtime for the pod status for pods[1].
	statusErr := fmt.Errorf("unable to get status")
	runtimeMock.On("GetPodStatus", pods[1].ID, "", "").Return(&kubecontainer.PodStatus{}, statusErr).Once()

	pleg.relist()
	actualEvents := getEventsFromChannel(ch)
	cases := []struct {
		pod    *kubecontainer.Pod
		status *kubecontainer.PodStatus
		error  error
	}{
		{pod: pods[0], status: statuses[0], error: nil},
		{pod: pods[1], status: &kubecontainer.PodStatus{}, error: statusErr},
	}
	for i, c := range cases {
		testStr := fmt.Sprintf("test[%d]", i)
		actualStatus, actualErr := pleg.cache.Get(c.pod.ID)
		assert.Equal(t, c.status, actualStatus, testStr)
		assert.Equal(t, c.error, actualErr, testStr)
	}
	// pleg should not generate any event for pods[1] because of the error.
	assert.Exactly(t, []*PodLifecycleEvent{events[0]}, actualEvents)

	// Return normal status for pods[1].
	runtimeMock.On("GetPodStatus", pods[1].ID, "", "").Return(statuses[1], nil).Once()
	pleg.relist()
	actualEvents = getEventsFromChannel(ch)
	cases = []struct {
		pod    *kubecontainer.Pod
		status *kubecontainer.PodStatus
		error  error
	}{
		{pod: pods[0], status: statuses[0], error: nil},
		{pod: pods[1], status: statuses[1], error: nil},
	}
	for i, c := range cases {
		testStr := fmt.Sprintf("test[%d]", i)
		actualStatus, actualErr := pleg.cache.Get(c.pod.ID)
		assert.Equal(t, c.status, actualStatus, testStr)
		assert.Equal(t, c.error, actualErr, testStr)
	}
	// Now that we are able to query status for pods[1], pleg should generate an event.
	assert.Exactly(t, []*PodLifecycleEvent{events[1]}, actualEvents)
}

func TestRemoveCacheEntry(t *testing.T) {
	pleg, runtimeMock := newTestGenericPLEGWithRuntimeMock()
	pods, statuses, _ := createTestPodsStatusesAndEvents(1)
	runtimeMock.On("GetPods", true).Return(pods, nil).Once()
	runtimeMock.On("GetPodStatus", pods[0].ID, "", "").Return(statuses[0], nil).Once()
	// Does a relist to populate the cache.
	pleg.relist()
	// Delete the pod from runtime. Verify that the cache entry has been
	// removed after relisting.
	runtimeMock.On("GetPods", true).Return([]*kubecontainer.Pod{}, nil).Once()
	pleg.relist()
	actualStatus, actualErr := pleg.cache.Get(pods[0].ID)
	assert.Equal(t, &kubecontainer.PodStatus{ID: pods[0].ID}, actualStatus)
	assert.Equal(t, nil, actualErr)
}