/*
Copyright 2016 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 e2e_node

import (
	"fmt"
	"time"

	"k8s.io/kubernetes/pkg/api/resource"
	"k8s.io/kubernetes/pkg/api/v1"
	metav1 "k8s.io/kubernetes/pkg/apis/meta/v1"
	"k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/stats"
	"k8s.io/kubernetes/test/e2e/framework"

	systemdutil "github.com/coreos/go-systemd/util"
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
	"github.com/onsi/gomega/gstruct"
	"github.com/onsi/gomega/types"
)

var _ = framework.KubeDescribe("Summary API", func() {
	f := framework.NewDefaultFramework("summary-test")
	Context("when querying /stats/summary", func() {
		AfterEach(func() {
			if CurrentGinkgoTestDescription().Failed && framework.TestContext.DumpLogsOnFailure {
				framework.LogFailedContainers(f.ClientSet, f.Namespace.Name, framework.Logf)
			}
		})
		It("should report resource usage through the stats api", func() {
			const pod0 = "stats-busybox-0"
			const pod1 = "stats-busybox-1"

			By("Creating test pods")
			createSummaryTestPods(f, pod0, pod1)
			// Wait for cAdvisor to collect 2 stats points
			time.Sleep(15 * time.Second)

			// Setup expectations.
			const (
				kb int64 = 1000
				mb int64 = 1000 * kb
				gb int64 = 1000 * mb
				tb int64 = 1000 * gb

				maxStartAge = time.Hour * 24 * 365 // 1 year
				maxStatsAge = time.Minute
			)
			fsCapacityBounds := bounded(100*mb, 100*gb)
			// Expectations for system containers.
			sysContExpectations := gstruct.MatchAllFields(gstruct.Fields{
				"Name":      gstruct.Ignore(),
				"StartTime": recent(maxStartAge),
				"CPU": ptrMatchAllFields(gstruct.Fields{
					"Time":                 recent(maxStatsAge),
					"UsageNanoCores":       bounded(100000, 2E9),
					"UsageCoreNanoSeconds": bounded(10000000, 1E15),
				}),
				"Memory": ptrMatchAllFields(gstruct.Fields{
					"Time": recent(maxStatsAge),
					// We don't limit system container memory.
					"AvailableBytes":  BeNil(),
					"UsageBytes":      bounded(1*mb, 10*gb),
					"WorkingSetBytes": bounded(1*mb, 10*gb),
					"RSSBytes":        bounded(1*mb, 1*gb),
					"PageFaults":      bounded(1000, 1E9),
					"MajorPageFaults": bounded(0, 100000),
				}),
				"Rootfs":             BeNil(),
				"Logs":               BeNil(),
				"UserDefinedMetrics": BeEmpty(),
			})
			systemContainers := gstruct.Elements{
				"kubelet": sysContExpectations,
				"runtime": sysContExpectations,
			}
			// The Kubelet only manages the 'misc' system container if the host is not running systemd.
			if !systemdutil.IsRunningSystemd() {
				framework.Logf("Host not running systemd; expecting 'misc' system container.")
				systemContainers["misc"] = sysContExpectations
			}
			// Expectations for pods.
			podExpectations := gstruct.MatchAllFields(gstruct.Fields{
				"PodRef":    gstruct.Ignore(),
				"StartTime": recent(maxStartAge),
				"Containers": gstruct.MatchAllElements(summaryObjectID, gstruct.Elements{
					"busybox-container": gstruct.MatchAllFields(gstruct.Fields{
						"Name":      Equal("busybox-container"),
						"StartTime": recent(maxStartAge),
						"CPU": ptrMatchAllFields(gstruct.Fields{
							"Time":                 recent(maxStatsAge),
							"UsageNanoCores":       bounded(100000, 100000000),
							"UsageCoreNanoSeconds": bounded(10000000, 1000000000),
						}),
						"Memory": ptrMatchAllFields(gstruct.Fields{
							"Time":            recent(maxStatsAge),
							"AvailableBytes":  bounded(1*mb, 10*mb),
							"UsageBytes":      bounded(10*kb, 5*mb),
							"WorkingSetBytes": bounded(10*kb, mb),
							"RSSBytes":        bounded(1*kb, mb),
							"PageFaults":      bounded(100, 100000),
							"MajorPageFaults": bounded(0, 10),
						}),
						"Rootfs": ptrMatchAllFields(gstruct.Fields{
							"AvailableBytes": fsCapacityBounds,
							"CapacityBytes":  fsCapacityBounds,
							"UsedBytes":      bounded(kb, 10*mb),
							"InodesFree":     bounded(1E4, 1E8),
							"Inodes":         bounded(1E4, 1E8),
							"InodesUsed":     bounded(0, 1E8),
						}),
						"Logs": ptrMatchAllFields(gstruct.Fields{
							"AvailableBytes": fsCapacityBounds,
							"CapacityBytes":  fsCapacityBounds,
							"UsedBytes":      bounded(kb, 10*mb),
							"InodesFree":     bounded(1E4, 1E8),
							"Inodes":         bounded(1E4, 1E8),
							"InodesUsed":     bounded(0, 1E8),
						}),
						"UserDefinedMetrics": BeEmpty(),
					}),
				}),
				"Network": ptrMatchAllFields(gstruct.Fields{
					"Time":     recent(maxStatsAge),
					"RxBytes":  bounded(10, 10*mb),
					"RxErrors": bounded(0, 1000),
					"TxBytes":  bounded(10, 10*mb),
					"TxErrors": bounded(0, 1000),
				}),
				"VolumeStats": gstruct.MatchAllElements(summaryObjectID, gstruct.Elements{
					"test-empty-dir": gstruct.MatchAllFields(gstruct.Fields{
						"Name": Equal("test-empty-dir"),
						"FsStats": gstruct.MatchAllFields(gstruct.Fields{
							"AvailableBytes": fsCapacityBounds,
							"CapacityBytes":  fsCapacityBounds,
							"UsedBytes":      bounded(kb, 1*mb),
							"InodesFree":     bounded(1E4, 1E8),
							"Inodes":         bounded(1E4, 1E8),
							"InodesUsed":     bounded(0, 1E8),
						}),
					}),
				}),
			})
			matchExpectations := ptrMatchAllFields(gstruct.Fields{
				"Node": gstruct.MatchAllFields(gstruct.Fields{
					"NodeName":         Equal(framework.TestContext.NodeName),
					"StartTime":        recent(maxStartAge),
					"SystemContainers": gstruct.MatchAllElements(summaryObjectID, systemContainers),
					"CPU": ptrMatchAllFields(gstruct.Fields{
						"Time":                 recent(maxStatsAge),
						"UsageNanoCores":       bounded(100E3, 2E9),
						"UsageCoreNanoSeconds": bounded(1E9, 1E15),
					}),
					"Memory": ptrMatchAllFields(gstruct.Fields{
						"Time":            recent(maxStatsAge),
						"AvailableBytes":  bounded(100*mb, 100*gb),
						"UsageBytes":      bounded(10*mb, 10*gb),
						"WorkingSetBytes": bounded(10*mb, 10*gb),
						"RSSBytes":        bounded(1*kb, 1*gb),
						"PageFaults":      bounded(1000, 1E9),
						"MajorPageFaults": bounded(0, 100000),
					}),
					// TODO(#28407): Handle non-eth0 network interface names.
					"Network": Or(BeNil(), ptrMatchAllFields(gstruct.Fields{
						"Time":     recent(maxStatsAge),
						"RxBytes":  bounded(1*mb, 100*gb),
						"RxErrors": bounded(0, 100000),
						"TxBytes":  bounded(10*kb, 10*gb),
						"TxErrors": bounded(0, 100000),
					})),
					"Fs": ptrMatchAllFields(gstruct.Fields{
						"AvailableBytes": fsCapacityBounds,
						"CapacityBytes":  fsCapacityBounds,
						"UsedBytes":      bounded(kb, 10*gb),
						"InodesFree":     bounded(1E4, 1E8),
						"Inodes":         bounded(1E4, 1E8),
						"InodesUsed":     bounded(0, 1E8),
					}),
					"Runtime": ptrMatchAllFields(gstruct.Fields{
						"ImageFs": ptrMatchAllFields(gstruct.Fields{
							"AvailableBytes": fsCapacityBounds,
							"CapacityBytes":  fsCapacityBounds,
							"UsedBytes":      bounded(kb, 10*gb),
							"InodesFree":     bounded(1E4, 1E8),
							"Inodes":         bounded(1E4, 1E8),
							"InodesUsed":     bounded(0, 1E8),
						}),
					}),
				}),
				// Ignore extra pods since the tests run in parallel.
				"Pods": gstruct.MatchElements(summaryObjectID, gstruct.IgnoreExtras, gstruct.Elements{
					fmt.Sprintf("%s::%s", f.Namespace.Name, pod0): podExpectations,
					fmt.Sprintf("%s::%s", f.Namespace.Name, pod1): podExpectations,
				}),
			})

			By("Validating /stats/summary")
			// Give pods a minute to actually start up.
			Eventually(getNodeSummary, 1*time.Minute, 15*time.Second).Should(matchExpectations)
			// Then the summary should match the expectations a few more times.
			Consistently(getNodeSummary, 30*time.Second, 15*time.Second).Should(matchExpectations)
		})
	})
})

func createSummaryTestPods(f *framework.Framework, names ...string) {
	pods := make([]*v1.Pod, 0, len(names))
	for _, name := range names {
		pods = append(pods, &v1.Pod{
			ObjectMeta: v1.ObjectMeta{
				Name: name,
			},
			Spec: v1.PodSpec{
				RestartPolicy: v1.RestartPolicyAlways,
				Containers: []v1.Container{
					{
						Name:    "busybox-container",
						Image:   "gcr.io/google_containers/busybox:1.24",
						Command: []string{"sh", "-c", "ping -c 1 google.com; while true; do echo 'hello world' >> /test-empty-dir-mnt/file ; sleep 1; done"},
						Resources: v1.ResourceRequirements{
							Limits: v1.ResourceList{
								// Must set memory limit to get MemoryStats.AvailableBytes
								v1.ResourceMemory: resource.MustParse("10M"),
							},
						},
						VolumeMounts: []v1.VolumeMount{
							{MountPath: "/test-empty-dir-mnt", Name: "test-empty-dir"},
						},
					},
				},
				SecurityContext: &v1.PodSecurityContext{
					SELinuxOptions: &v1.SELinuxOptions{
						Level: "s0",
					},
				},
				Volumes: []v1.Volume{
					// TODO(#28393): Test secret volumes
					// TODO(#28394): Test hostpath volumes
					{Name: "test-empty-dir", VolumeSource: v1.VolumeSource{EmptyDir: &v1.EmptyDirVolumeSource{}}},
				},
			},
		})
	}
	f.PodClient().CreateBatch(pods)
}

// Mapping function for gstruct.MatchAllElements
func summaryObjectID(element interface{}) string {
	switch el := element.(type) {
	case stats.PodStats:
		return fmt.Sprintf("%s::%s", el.PodRef.Namespace, el.PodRef.Name)
	case stats.ContainerStats:
		return el.Name
	case stats.VolumeStats:
		return el.Name
	case stats.UserDefinedMetric:
		return el.Name
	default:
		framework.Failf("Unknown type: %T", el)
		return "???"
	}
}

// Convenience functions for common matcher combinations.
func ptrMatchAllFields(fields gstruct.Fields) types.GomegaMatcher {
	return gstruct.PointTo(gstruct.MatchAllFields(fields))
}

func bounded(lower, upper interface{}) types.GomegaMatcher {
	return gstruct.PointTo(And(
		BeNumerically(">=", lower),
		BeNumerically("<=", upper)))
}

func recent(d time.Duration) types.GomegaMatcher {
	return WithTransform(func(t metav1.Time) time.Time {
		return t.Time
	}, And(
		BeTemporally(">=", time.Now().Add(-d)),
		// Now() is the test start time, not the match time, so permit a few extra minutes.
		BeTemporally("<", time.Now().Add(2*time.Minute))))
}
