fix node and kubelet start times

pkg/kubelet/server/stats/BUILD

@@ -18,6 +18,7 @@ go_library(
         "//pkg/kubelet/apis/stats/v1alpha1:go_default_library",
         "//pkg/kubelet/cm:go_default_library",
         "//pkg/kubelet/container:go_default_library",
+        "//pkg/kubelet/util:go_default_library",
         "//pkg/kubelet/util/format:go_default_library",
         "//pkg/volume:go_default_library",
         "//staging/src/k8s.io/api/core/v1:go_default_library",

pkg/kubelet/server/stats/summary.go

@@ -19,7 +19,11 @@ package stats
 import (
 	"fmt"
 
+	"k8s.io/klog"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	statsapi "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
+	"k8s.io/kubernetes/pkg/kubelet/util"
 )
 
 type SummaryProvider interface {
@@ -32,6 +36,11 @@ type SummaryProvider interface {
 
 // summaryProviderImpl implements the SummaryProvider interface.
 type summaryProviderImpl struct {
+	// kubeletCreationTime is the time at which the summaryProvider was created.
+	kubeletCreationTime metav1.Time
+	// systemBootTime is the time at which the system was started
+	systemBootTime metav1.Time
+
 	provider StatsProvider
 }
 
@@ -40,7 +49,18 @@ var _ SummaryProvider = &summaryProviderImpl{}
 // NewSummaryProvider returns a SummaryProvider using the stats provided by the
 // specified statsProvider.
 func NewSummaryProvider(statsProvider StatsProvider) SummaryProvider {
-	return &summaryProviderImpl{statsProvider}
+	kubeletCreationTime := metav1.Now()
+	bootTime, err := util.GetBootTime()
+	if err != nil {
+		// bootTime will be zero if we encounter an error getting the boot time.
+		klog.Warningf("Error getting system boot time.  Node metrics will have an incorrect start time: %v", err)
+	}
+
+	return &summaryProviderImpl{
+		kubeletCreationTime: kubeletCreationTime,
+		systemBootTime:      metav1.NewTime(bootTime),
+		provider:            statsProvider,
+	}
 }
 
 func (sp *summaryProviderImpl) Get(updateStats bool) (*statsapi.Summary, error) {
@@ -77,7 +97,7 @@ func (sp *summaryProviderImpl) Get(updateStats bool) (*statsapi.Summary, error)
 		CPU:              rootStats.CPU,
 		Memory:           rootStats.Memory,
 		Network:          networkStats,
-		StartTime:        rootStats.StartTime,
+		StartTime:        sp.systemBootTime,
 		Fs:               rootFsStats,
 		Runtime:          &statsapi.RuntimeStats{ImageFs: imageFsStats},
 		Rlimit:           rlimit,

pkg/kubelet/server/stats/summary_sys_containers.go

@@ -21,6 +21,7 @@ package stats
 import (
 	"k8s.io/klog"
 
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	statsapi "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
 	"k8s.io/kubernetes/pkg/kubelet/cm"
 )
@@ -29,11 +30,12 @@ func (sp *summaryProviderImpl) GetSystemContainersStats(nodeConfig cm.NodeConfig
 	systemContainers := map[string]struct {
 		name             string
 		forceStatsUpdate bool
+		startTime        metav1.Time
 	}{
-		statsapi.SystemContainerKubelet: {nodeConfig.KubeletCgroupsName, false},
-		statsapi.SystemContainerRuntime: {nodeConfig.RuntimeCgroupsName, false},
-		statsapi.SystemContainerMisc:    {nodeConfig.SystemCgroupsName, false},
-		statsapi.SystemContainerPods:    {sp.provider.GetPodCgroupRoot(), updateStats},
+		statsapi.SystemContainerKubelet: {name: nodeConfig.KubeletCgroupsName, forceStatsUpdate: false, startTime: sp.kubeletCreationTime},
+		statsapi.SystemContainerRuntime: {name: nodeConfig.RuntimeCgroupsName, forceStatsUpdate: false},
+		statsapi.SystemContainerMisc:    {name: nodeConfig.SystemCgroupsName, forceStatsUpdate: false},
+		statsapi.SystemContainerPods:    {name: sp.provider.GetPodCgroupRoot(), forceStatsUpdate: updateStats},
 	}
 	for sys, cont := range systemContainers {
 		// skip if cgroup name is undefined (not all system containers are required)
@@ -48,6 +50,11 @@ func (sp *summaryProviderImpl) GetSystemContainersStats(nodeConfig cm.NodeConfig
 		// System containers don't have a filesystem associated with them.
 		s.Logs, s.Rootfs = nil, nil
 		s.Name = sys
+
+		// if we know the start time of a system container, use that instead of the start time provided by cAdvisor
+		if !cont.startTime.IsZero() {
+			s.StartTime = cont.startTime
+		}
 		stats = append(stats, *s)
 	}
 
@@ -58,11 +65,12 @@ func (sp *summaryProviderImpl) GetSystemContainersCPUAndMemoryStats(nodeConfig c
 	systemContainers := map[string]struct {
 		name             string
 		forceStatsUpdate bool
+		startTime        metav1.Time
 	}{
-		statsapi.SystemContainerKubelet: {nodeConfig.KubeletCgroupsName, false},
-		statsapi.SystemContainerRuntime: {nodeConfig.RuntimeCgroupsName, false},
-		statsapi.SystemContainerMisc:    {nodeConfig.SystemCgroupsName, false},
-		statsapi.SystemContainerPods:    {sp.provider.GetPodCgroupRoot(), updateStats},
+		statsapi.SystemContainerKubelet: {name: nodeConfig.KubeletCgroupsName, forceStatsUpdate: false, startTime: sp.kubeletCreationTime},
+		statsapi.SystemContainerRuntime: {name: nodeConfig.RuntimeCgroupsName, forceStatsUpdate: false},
+		statsapi.SystemContainerMisc:    {name: nodeConfig.SystemCgroupsName, forceStatsUpdate: false},
+		statsapi.SystemContainerPods:    {name: sp.provider.GetPodCgroupRoot(), forceStatsUpdate: updateStats},
 	}
 	for sys, cont := range systemContainers {
 		// skip if cgroup name is undefined (not all system containers are required)
@@ -75,6 +83,11 @@ func (sp *summaryProviderImpl) GetSystemContainersCPUAndMemoryStats(nodeConfig c
 			continue
 		}
 		s.Name = sys
+
+		// if we know the start time of a system container, use that instead of the start time provided by cAdvisor
+		if !cont.startTime.IsZero() {
+			s.StartTime = cont.startTime
+		}
 		stats = append(stats, *s)
 	}
 

pkg/kubelet/server/stats/summary_test.go

@@ -83,12 +83,14 @@ func TestSummaryProviderGetStats(t *testing.T) {
 		On("GetCgroupStats", "/kubelet", false).Return(cgroupStatsMap["/kubelet"].cs, cgroupStatsMap["/kubelet"].ns, nil).
 		On("GetCgroupStats", "/kubepods", true).Return(cgroupStatsMap["/pods"].cs, cgroupStatsMap["/pods"].ns, nil)
 
-	provider := NewSummaryProvider(mockStatsProvider)
+	kubeletCreationTime := metav1.Now()
+	systemBootTime := metav1.Now()
+	provider := summaryProviderImpl{kubeletCreationTime: kubeletCreationTime, systemBootTime: systemBootTime, provider: mockStatsProvider}
 	summary, err := provider.Get(true)
 	assert.NoError(err)
 
 	assert.Equal(summary.Node.NodeName, "test-node")
-	assert.Equal(summary.Node.StartTime, cgroupStatsMap["/"].cs.StartTime)
+	assert.Equal(summary.Node.StartTime, systemBootTime)
 	assert.Equal(summary.Node.CPU, cgroupStatsMap["/"].cs.CPU)
 	assert.Equal(summary.Node.Memory, cgroupStatsMap["/"].cs.Memory)
 	assert.Equal(summary.Node.Network, cgroupStatsMap["/"].ns)
@@ -98,7 +100,7 @@ func TestSummaryProviderGetStats(t *testing.T) {
 	assert.Equal(len(summary.Node.SystemContainers), 4)
 	assert.Contains(summary.Node.SystemContainers, statsapi.ContainerStats{
 		Name:               "kubelet",
-		StartTime:          cgroupStatsMap["/kubelet"].cs.StartTime,
+		StartTime:          kubeletCreationTime,
 		CPU:                cgroupStatsMap["/kubelet"].cs.CPU,
 		Memory:             cgroupStatsMap["/kubelet"].cs.Memory,
 		Accelerators:       cgroupStatsMap["/kubelet"].cs.Accelerators,

pkg/kubelet/util/BUILD

@@ -34,6 +34,8 @@ go_test(
 go_library(
     name = "go_default_library",
     srcs = [
+        "boottime_util_darwin.go",
+        "boottime_util_linux.go",
         "doc.go",
         "util.go",
         "util_unix.go",

pkg/kubelet/util/boottime_util_darwin.go

@@ -0,0 +1,44 @@
+// +build darwin
+
+/*
+Copyright 2018 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 util
+
+import (
+	"fmt"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// GetBootTime returns the time at which the machine was started, truncated to the nearest second
+func GetBootTime() (time.Time, error) {
+	output, err := unix.SysctlRaw("kern.boottime")
+	if err != nil {
+		return time.Time{}, err
+	}
+	var timeval syscall.Timeval
+	if len(output) != int(unsafe.Sizeof(timeval)) {
+		return time.Time{}, fmt.Errorf("unexpected output when calling syscall kern.bootime.  Expected len(output) to be %v, but got %v",
+			int(unsafe.Sizeof(timeval)), len(output))
+	}
+	timeval = *(*syscall.Timeval)(unsafe.Pointer(&output[0]))
+	sec, nsec := timeval.Unix()
+	return time.Unix(sec, nsec).Truncate(time.Second), nil
+}

pkg/kubelet/util/boottime_util_linux.go

@@ -0,0 +1,36 @@
+// +build freebsd linux
+
+/*
+Copyright 2018 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 util
+
+import (
+	"fmt"
+	"time"
+
+	"golang.org/x/sys/unix"
+)
+
+// GetBootTime returns the time at which the machine was started, truncated to the nearest second
+func GetBootTime() (time.Time, error) {
+	currentTime := time.Now()
+	var info unix.Sysinfo_t
+	if err := unix.Sysinfo(&info); err != nil {
+		return time.Time{}, fmt.Errorf("error getting system uptime: %s", err)
+	}
+	return currentTime.Add(-time.Duration(info.Uptime) * time.Second).Truncate(time.Second), nil
+}

pkg/kubelet/util/util_unsupported.go

@@ -45,3 +45,8 @@ func UnlockPath(fileHandles []uintptr) {
 func LocalEndpoint(path, file string) string {
 	return ""
 }
+
+// GetBootTime empty implementation
+func GetBootTime() (time.Time, error) {
+	return time.Time{}, fmt.Errorf("GetBootTime is unsupported in this build")
+}

pkg/kubelet/util/util_windows.go

@@ -23,6 +23,7 @@ import (
 	"net"
 	"net/url"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/Microsoft/go-winio"
@@ -112,3 +113,15 @@ func LocalEndpoint(path, file string) string {
 	}
 	return u.String() + "//./pipe/" + file
 }
+
+var tickCount = syscall.NewLazyDLL("kernel32.dll").NewProc("GetTickCount64")
+
+// GetBootTime returns the time at which the machine was started, truncated to the nearest second
+func GetBootTime() (time.Time, error) {
+	currentTime := time.Now()
+	output, _, err := tickCount.Call()
+	if errno, ok := err.(syscall.Errno); !ok || errno != 0 {
+		return time.Time{}, err
+	}
+	return currentTime.Add(-time.Duration(output) * time.Millisecond).Truncate(time.Second), nil
+}

test/e2e_node/node_problem_detector_linux.go

@@ -22,7 +22,6 @@ import (
 	"fmt"
 	"os"
 	"path"
-	"syscall"
 	"time"
 
 	"k8s.io/api/core/v1"
@@ -34,6 +33,7 @@ import (
 	clientset "k8s.io/client-go/kubernetes"
 	coreclientset "k8s.io/client-go/kubernetes/typed/core/v1"
 	nodeutil "k8s.io/kubernetes/pkg/api/v1/node"
+	"k8s.io/kubernetes/pkg/kubelet/util"
 	"k8s.io/kubernetes/test/e2e/framework"
 
 	. "github.com/onsi/ginkgo"
@@ -97,8 +97,11 @@ var _ = framework.KubeDescribe("NodeProblemDetector [NodeFeature:NodeProblemDete
 		BeforeEach(func() {
 			By("Calculate Lookback duration")
 			var err error
-			nodeTime, bootTime, err = getNodeTime()
+
+			nodeTime = time.Now()
+			bootTime, err = util.GetBootTime()
 			Expect(err).To(BeNil())
+
 			// Set lookback duration longer than node up time.
 			// Assume the test won't take more than 1 hour, in fact it usually only takes 90 seconds.
 			lookback = nodeTime.Sub(bootTime) + time.Hour
@@ -387,24 +390,6 @@ func injectLog(file string, timestamp time.Time, log string, num int) error {
 	return nil
 }
 
-// getNodeTime gets node boot time and current time.
-func getNodeTime() (time.Time, time.Time, error) {
-	// Get node current time.
-	nodeTime := time.Now()
-
-	// Get system uptime.
-	var info syscall.Sysinfo_t
-	if err := syscall.Sysinfo(&info); err != nil {
-		return time.Time{}, time.Time{}, err
-	}
-	// Get node boot time. NOTE that because we get node current time before uptime, the boot time
-	// calculated will be a little earlier than the real boot time. This won't affect the correctness
-	// of the test result.
-	bootTime := nodeTime.Add(-time.Duration(info.Uptime) * time.Second)
-
-	return nodeTime, bootTime, nil
-}
-
 // verifyEvents verifies there are num specific events generated
 func verifyEvents(e coreclientset.EventInterface, options metav1.ListOptions, num int, reason, message string) error {
 	events, err := e.List(options)