// Copyright 2014 Google Inc. 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 manager
import (
"flag"
"fmt"
"io/ioutil"
"math"
"math/rand"
"os/exec"
"path"
"regexp"
"sort"
"strconv"
"strings"
"sync"
"time"
"github.com/google/cadvisor/cache/memory"
"github.com/google/cadvisor/collector"
"github.com/google/cadvisor/container"
info "github.com/google/cadvisor/info/v1"
"github.com/google/cadvisor/info/v2"
"github.com/google/cadvisor/summary"
"github.com/google/cadvisor/utils/cpuload"
units "github.com/docker/go-units"
"github.com/golang/glog"
)
// Housekeeping interval.
var enableLoadReader = flag.Bool("enable_load_reader", false, "Whether to enable cpu load reader")
var HousekeepingInterval = flag.Duration("housekeeping_interval", 1*time.Second, "Interval between container housekeepings")
var cgroupPathRegExp = regexp.MustCompile(`devices[^:]*:(.*?)[,;$]`)
type containerInfo struct {
info.ContainerReference
Subcontainers []info.ContainerReference
Spec info.ContainerSpec
}
type containerData struct {
handler container.ContainerHandler
info containerInfo
memoryCache *memory.InMemoryCache
lock sync.Mutex
loadReader cpuload.CpuLoadReader
summaryReader *summary.StatsSummary
loadAvg float64 // smoothed load average seen so far.
housekeepingInterval time.Duration
maxHousekeepingInterval time.Duration
allowDynamicHousekeeping bool
lastUpdatedTime time.Time
lastErrorTime time.Time
// Decay value used for load average smoothing. Interval length of 10 seconds is used.
loadDecay float64
// Whether to log the usage of this container when it is updated.
logUsage bool
// Tells the container to stop.
stop chan bool
// Runs custom metric collectors.
collectorManager collector.CollectorManager
}
// jitter returns a time.Duration between duration and duration + maxFactor * duration,
// to allow clients to avoid converging on periodic behavior. If maxFactor is 0.0, a
// suggested default value will be chosen.
func jitter(duration time.Duration, maxFactor float64) time.Duration {
if maxFactor <= 0.0 {
maxFactor = 1.0
}
wait := duration + time.Duration(rand.Float64()*maxFactor*float64(duration))
return wait
}
func (c *containerData) Start() error {
go c.housekeeping()
return nil
}
func (c *containerData) Stop() error {
err := c.memoryCache.RemoveContainer(c.info.Name)
if err != nil {
return err
}
c.stop <- true
return nil
}
func (c *containerData) allowErrorLogging() bool {
if time.Since(c.lastErrorTime) > time.Minute {
c.lastErrorTime = time.Now()
return true
}
return false
}
func (c *containerData) GetInfo() (*containerInfo, error) {
// Get spec and subcontainers.
if time.Since(c.lastUpdatedTime) > 5*time.Second {
err := c.updateSpec()
if err != nil {
return nil, err
}
err = c.updateSubcontainers()
if err != nil {
return nil, err
}
c.lastUpdatedTime = time.Now()
}
// Make a copy of the info for the user.
c.lock.Lock()
defer c.lock.Unlock()
return &c.info, nil
}
func (c *containerData) DerivedStats() (v2.DerivedStats, error) {
if c.summaryReader == nil {
return v2.DerivedStats{}, fmt.Errorf("derived stats not enabled for container %q", c.info.Name)
}
return c.summaryReader.DerivedStats()
}
func (c *containerData) getCgroupPath(cgroups string) (string, error) {
if cgroups == "-" {
return "/", nil
}
matches := cgroupPathRegExp.FindSubmatch([]byte(cgroups))
if len(matches) != 2 {
glog.V(3).Infof("failed to get devices cgroup path from %q", cgroups)
// return root in case of failures - devices hierarchy might not be enabled.
return "/", nil
}
return string(matches[1]), nil
}
// Returns contents of a file inside the container root.
// Takes in a path relative to container root.
func (c *containerData) ReadFile(filepath string, inHostNamespace bool) ([]byte, error) {
pids, err := c.getContainerPids(inHostNamespace)
if err != nil {
return nil, err
}
// TODO(rjnagal): Optimize by just reading container's cgroup.proc file when in host namespace.
rootfs := "/"
if !inHostNamespace {
rootfs = "/rootfs"
}
for _, pid := range pids {
filePath := path.Join(rootfs, "/proc", pid, "/root", filepath)
glog.V(3).Infof("Trying path %q", filePath)
data, err := ioutil.ReadFile(filePath)
if err == nil {
return data, err
}
}
// No process paths could be found. Declare config non-existent.
return nil, fmt.Errorf("file %q does not exist.", filepath)
}
// Return output for ps command in host /proc with specified format
func (c *containerData) getPsOutput(inHostNamespace bool, format string) ([]byte, error) {
args := []string{}
command := "ps"
if !inHostNamespace {
command = "/usr/sbin/chroot"
args = append(args, "/rootfs", "ps")
}
args = append(args, "-e", "-o", format)
out, err := exec.Command(command, args...).Output()
if err != nil {
return nil, fmt.Errorf("failed to execute %q command: %v", command, err)
}
return out, err
}
// Get pids of processes in this container.
// A slightly lighterweight call than GetProcessList if other details are not required.
func (c *containerData) getContainerPids(inHostNamespace bool) ([]string, error) {
format := "pid,cgroup"
out, err := c.getPsOutput(inHostNamespace, format)
if err != nil {
return nil, err
}
expectedFields := 2
lines := strings.Split(string(out), "\n")
pids := []string{}
for _, line := range lines[1:] {
if len(line) == 0 {
continue
}
fields := strings.Fields(line)
if len(fields) < expectedFields {
return nil, fmt.Errorf("expected at least %d fields, found %d: output: %q", expectedFields, len(fields), line)
}
pid := fields[0]
cgroup, err := c.getCgroupPath(fields[1])
if err != nil {
return nil, fmt.Errorf("could not parse cgroup path from %q: %v", fields[1], err)
}
if c.info.Name == cgroup {
pids = append(pids, pid)
}
}
return pids, nil
}
func (c *containerData) GetProcessList(cadvisorContainer string, inHostNamespace bool) ([]v2.ProcessInfo, error) {
// report all processes for root.
isRoot := c.info.Name == "/"
format := "user,pid,ppid,stime,pcpu,pmem,rss,vsz,stat,time,comm,cgroup"
out, err := c.getPsOutput(inHostNamespace, format)
if err != nil {
return nil, err
}
expectedFields := 12
processes := []v2.ProcessInfo{}
lines := strings.Split(string(out), "\n")
for _, line := range lines[1:] {
if len(line) == 0 {
continue
}
fields := strings.Fields(line)
if len(fields) < expectedFields {
return nil, fmt.Errorf("expected at least %d fields, found %d: output: %q", expectedFields, len(fields), line)
}
pid, err := strconv.Atoi(fields[1])
if err != nil {
return nil, fmt.Errorf("invalid pid %q: %v", fields[1], err)
}
ppid, err := strconv.Atoi(fields[2])
if err != nil {
return nil, fmt.Errorf("invalid ppid %q: %v", fields[2], err)
}
percentCpu, err := strconv.ParseFloat(fields[4], 32)
if err != nil {
return nil, fmt.Errorf("invalid cpu percent %q: %v", fields[4], err)
}
percentMem, err := strconv.ParseFloat(fields[5], 32)
if err != nil {
return nil, fmt.Errorf("invalid memory percent %q: %v", fields[5], err)
}
rss, err := strconv.ParseUint(fields[6], 0, 64)
if err != nil {
return nil, fmt.Errorf("invalid rss %q: %v", fields[6], err)
}
// convert to bytes
rss *= 1024
vs, err := strconv.ParseUint(fields[7], 0, 64)
if err != nil {
return nil, fmt.Errorf("invalid virtual size %q: %v", fields[7], err)
}
// convert to bytes
vs *= 1024
cgroup, err := c.getCgroupPath(fields[11])
if err != nil {
return nil, fmt.Errorf("could not parse cgroup path from %q: %v", fields[11], err)
}
// Remove the ps command we just ran from cadvisor container.
// Not necessary, but makes the cadvisor page look cleaner.
if !inHostNamespace && cadvisorContainer == cgroup && fields[10] == "ps" {
continue
}
var cgroupPath string
if isRoot {
cgroupPath = cgroup
}
if isRoot || c.info.Name == cgroup {
processes = append(processes, v2.ProcessInfo{
User: fields[0],
Pid: pid,
Ppid: ppid,
StartTime: fields[3],
PercentCpu: float32(percentCpu),
PercentMemory: float32(percentMem),
RSS: rss,
VirtualSize: vs,
Status: fields[8],
RunningTime: fields[9],
Cmd: fields[10],
CgroupPath: cgroupPath,
})
}
}
return processes, nil
}
func newContainerData(containerName string, memoryCache *memory.InMemoryCache, handler container.ContainerHandler, logUsage bool, collectorManager collector.CollectorManager, maxHousekeepingInterval time.Duration, allowDynamicHousekeeping bool) (*containerData, error) {
if memoryCache == nil {
return nil, fmt.Errorf("nil memory storage")
}
if handler == nil {
return nil, fmt.Errorf("nil container handler")
}
ref, err := handler.ContainerReference()
if err != nil {
return nil, err
}
cont := &containerData{
handler: handler,
memoryCache: memoryCache,
housekeepingInterval: *HousekeepingInterval,
maxHousekeepingInterval: maxHousekeepingInterval,
allowDynamicHousekeeping: allowDynamicHousekeeping,
logUsage: logUsage,
loadAvg: -1.0, // negative value indicates uninitialized.
stop: make(chan bool, 1),
collectorManager: collectorManager,
}
cont.info.ContainerReference = ref
cont.loadDecay = math.Exp(float64(-cont.housekeepingInterval.Seconds() / 10))
if *enableLoadReader {
// Create cpu load reader.
loadReader, err := cpuload.New()
if err != nil {
// TODO(rjnagal): Promote to warning once we support cpu load inside namespaces.
glog.Infof("Could not initialize cpu load reader for %q: %s", ref.Name, err)
} else {
cont.loadReader = loadReader
}
}
err = cont.updateSpec()
if err != nil {
return nil, err
}
cont.summaryReader, err = summary.New(cont.info.Spec)
if err != nil {
cont.summaryReader = nil
glog.Warningf("Failed to create summary reader for %q: %v", ref.Name, err)
}
return cont, nil
}
// Determine when the next housekeeping should occur.
func (self *containerData) nextHousekeeping(lastHousekeeping time.Time) time.Time {
if self.allowDynamicHousekeeping {
var empty time.Time
stats, err := self.memoryCache.RecentStats(self.info.Name, empty, empty, 2)
if err != nil {
if self.allowErrorLogging() {
glog.Warningf("Failed to get RecentStats(%q) while determining the next housekeeping: %v", self.info.Name, err)
}
} else if len(stats) == 2 {
// TODO(vishnuk): Use no processes as a signal.
// Raise the interval if usage hasn't changed in the last housekeeping.
if stats[0].StatsEq(stats[1]) && (self.housekeepingInterval < self.maxHousekeepingInterval) {
self.housekeepingInterval *= 2
if self.housekeepingInterval > self.maxHousekeepingInterval {
self.housekeepingInterval = self.maxHousekeepingInterval
}
} else if self.housekeepingInterval != *HousekeepingInterval {
// Lower interval back to the baseline.
self.housekeepingInterval = *HousekeepingInterval
}
}
}
return lastHousekeeping.Add(jitter(self.housekeepingInterval, 1.0))
}
// TODO(vmarmol): Implement stats collecting as a custom collector.
func (c *containerData) housekeeping() {
// Start any background goroutines - must be cleaned up in c.handler.Cleanup().
c.handler.Start()
defer c.handler.Cleanup()
// Initialize cpuload reader - must be cleaned up in c.loadReader.Stop()
if c.loadReader != nil {
err := c.loadReader.Start()
if err != nil {
glog.Warningf("Could not start cpu load stat collector for %q: %s", c.info.Name, err)
}
defer c.loadReader.Stop()
}
// Long housekeeping is either 100ms or half of the housekeeping interval.
longHousekeeping := 100 * time.Millisecond
if *HousekeepingInterval/2 < longHousekeeping {
longHousekeeping = *HousekeepingInterval / 2
}
// Housekeep every second.
glog.V(3).Infof("Start housekeeping for container %q\n", c.info.Name)
lastHousekeeping := time.Now()
for {
select {
case <-c.stop:
// Stop housekeeping when signaled.
return
default:
// Perform housekeeping.
start := time.Now()
c.housekeepingTick()
// Log if housekeeping took too long.
duration := time.Since(start)
if duration >= longHousekeeping {
glog.V(3).Infof("[%s] Housekeeping took %s", c.info.Name, duration)
}
}
// Log usage if asked to do so.
if c.logUsage {
const numSamples = 60
var empty time.Time
stats, err := c.memoryCache.RecentStats(c.info.Name, empty, empty, numSamples)
if err != nil {
if c.allowErrorLogging() {
glog.Infof("[%s] Failed to get recent stats for logging usage: %v", c.info.Name, err)
}
} else if len(stats) < numSamples {
// Ignore, not enough stats yet.
} else {
usageCpuNs := uint64(0)
for i := range stats {
if i > 0 {
usageCpuNs += (stats[i].Cpu.Usage.Total - stats[i-1].Cpu.Usage.Total)
}
}
usageMemory := stats[numSamples-1].Memory.Usage
instantUsageInCores := float64(stats[numSamples-1].Cpu.Usage.Total-stats[numSamples-2].Cpu.Usage.Total) / float64(stats[numSamples-1].Timestamp.Sub(stats[numSamples-2].Timestamp).Nanoseconds())
usageInCores := float64(usageCpuNs) / float64(stats[numSamples-1].Timestamp.Sub(stats[0].Timestamp).Nanoseconds())
usageInHuman := units.HumanSize(float64(usageMemory))
glog.Infof("[%s] %.3f cores (average: %.3f cores), %s of memory", c.info.Name, instantUsageInCores, usageInCores, usageInHuman)
}
}
next := c.nextHousekeeping(lastHousekeeping)
// Schedule the next housekeeping. Sleep until that time.
if time.Now().Before(next) {
time.Sleep(next.Sub(time.Now()))
} else {
next = time.Now()
}
lastHousekeeping = next
}
}
func (c *containerData) housekeepingTick() {
err := c.updateStats()
if err != nil {
if c.allowErrorLogging() {
glog.Infof("Failed to update stats for container \"%s\": %s", c.info.Name, err)
}
}
}
func (c *containerData) updateSpec() error {
spec, err := c.handler.GetSpec()
if err != nil {
// Ignore errors if the container is dead.
if !c.handler.Exists() {
return nil
}
return err
}
customMetrics, err := c.collectorManager.GetSpec()
if err != nil {
return err
}
if len(customMetrics) > 0 {
spec.HasCustomMetrics = true
spec.CustomMetrics = customMetrics
}
c.lock.Lock()
defer c.lock.Unlock()
c.info.Spec = spec
return nil
}
// Calculate new smoothed load average using the new sample of runnable threads.
// The decay used ensures that the load will stabilize on a new constant value within
// 10 seconds.
func (c *containerData) updateLoad(newLoad uint64) {
if c.loadAvg < 0 {
c.loadAvg = float64(newLoad) // initialize to the first seen sample for faster stabilization.
} else {
c.loadAvg = c.loadAvg*c.loadDecay + float64(newLoad)*(1.0-c.loadDecay)
}
}
func (c *containerData) updateStats() error {
stats, statsErr := c.handler.GetStats()
if statsErr != nil {
// Ignore errors if the container is dead.
if !c.handler.Exists() {
return nil
}
// Stats may be partially populated, push those before we return an error.
statsErr = fmt.Errorf("%v, continuing to push stats", statsErr)
}
if stats == nil {
return statsErr
}
if c.loadReader != nil {
// TODO(vmarmol): Cache this path.
path, err := c.handler.GetCgroupPath("cpu")
if err == nil {
loadStats, err := c.loadReader.GetCpuLoad(c.info.Name, path)
if err != nil {
return fmt.Errorf("failed to get load stat for %q - path %q, error %s", c.info.Name, path, err)
}
stats.TaskStats = loadStats
c.updateLoad(loadStats.NrRunning)
// convert to 'milliLoad' to avoid floats and preserve precision.
stats.Cpu.LoadAverage = int32(c.loadAvg * 1000)
}
}
if c.summaryReader != nil {
err := c.summaryReader.AddSample(*stats)
if err != nil {
// Ignore summary errors for now.
glog.V(2).Infof("Failed to add summary stats for %q: %v", c.info.Name, err)
}
}
var customStatsErr error
cm := c.collectorManager.(*collector.GenericCollectorManager)
if len(cm.Collectors) > 0 {
if cm.NextCollectionTime.Before(time.Now()) {
customStats, err := c.updateCustomStats()
if customStats != nil {
stats.CustomMetrics = customStats
}
if err != nil {
customStatsErr = err
}
}
}
ref, err := c.handler.ContainerReference()
if err != nil {
// Ignore errors if the container is dead.
if !c.handler.Exists() {
return nil
}
return err
}
err = c.memoryCache.AddStats(ref, stats)
if err != nil {
return err
}
if statsErr != nil {
return statsErr
}
return customStatsErr
}
func (c *containerData) updateCustomStats() (map[string][]info.MetricVal, error) {
_, customStats, customStatsErr := c.collectorManager.Collect()
if customStatsErr != nil {
if !c.handler.Exists() {
return customStats, nil
}
customStatsErr = fmt.Errorf("%v, continuing to push custom stats", customStatsErr)
}
return customStats, customStatsErr
}
func (c *containerData) updateSubcontainers() error {
var subcontainers info.ContainerReferenceSlice
subcontainers, err := c.handler.ListContainers(container.ListSelf)
if err != nil {
// Ignore errors if the container is dead.
if !c.handler.Exists() {
return nil
}
return err
}
sort.Sort(subcontainers)
c.lock.Lock()
defer c.lock.Unlock()
c.info.Subcontainers = subcontainers
return nil
}