kubernetes/vendor/github.com/google/cadvisor/fs/fs.go
2016-06-08 11:57:20 -07:00

560 lines
16 KiB
Go

// 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.
// +build linux
// Provides Filesystem Stats
package fs
import (
"bufio"
"fmt"
"io/ioutil"
"os"
"os/exec"
"path"
"path/filepath"
"regexp"
"strconv"
"strings"
"syscall"
"time"
"github.com/docker/docker/pkg/mount"
"github.com/golang/glog"
"github.com/google/cadvisor/devicemapper"
dockerutil "github.com/google/cadvisor/utils/docker"
zfs "github.com/mistifyio/go-zfs"
)
const (
LabelSystemRoot = "root"
LabelDockerImages = "docker-images"
LabelRktImages = "rkt-images"
)
// The maximum number of `du` tasks that can be running at once.
const maxConsecutiveDus = 20
// A pool for restricting the number of consecutive `du` tasks running.
var duPool = make(chan struct{}, maxConsecutiveDus)
func init() {
for i := 0; i < maxConsecutiveDus; i++ {
releaseDuToken()
}
}
func claimDuToken() {
<-duPool
}
func releaseDuToken() {
duPool <- struct{}{}
}
type partition struct {
mountpoint string
major uint
minor uint
fsType string
blockSize uint
}
type RealFsInfo struct {
// Map from block device path to partition information.
partitions map[string]partition
// Map from label to block device path.
// Labels are intent-specific tags that are auto-detected.
labels map[string]string
// devicemapper client
dmsetup devicemapper.DmsetupClient
}
type Context struct {
// docker root directory.
Docker DockerContext
RktPath string
}
type DockerContext struct {
Root string
Driver string
DriverStatus map[string]string
}
func NewFsInfo(context Context) (FsInfo, error) {
mounts, err := mount.GetMounts()
if err != nil {
return nil, err
}
fsInfo := &RealFsInfo{
partitions: make(map[string]partition, 0),
labels: make(map[string]string, 0),
dmsetup: devicemapper.NewDmsetupClient(),
}
supportedFsType := map[string]bool{
// all ext systems are checked through prefix.
"btrfs": true,
"xfs": true,
"zfs": true,
}
for _, mount := range mounts {
var Fstype string
if !strings.HasPrefix(mount.Fstype, "ext") && !supportedFsType[mount.Fstype] {
continue
}
// Avoid bind mounts.
if _, ok := fsInfo.partitions[mount.Source]; ok {
continue
}
if mount.Fstype == "zfs" {
Fstype = mount.Fstype
}
fsInfo.partitions[mount.Source] = partition{
fsType: Fstype,
mountpoint: mount.Mountpoint,
major: uint(mount.Major),
minor: uint(mount.Minor),
}
}
fsInfo.addRktImagesLabel(context, mounts)
// need to call this before the log line below printing out the partitions, as this function may
// add a "partition" for devicemapper to fsInfo.partitions
fsInfo.addDockerImagesLabel(context, mounts)
glog.Infof("Filesystem partitions: %+v", fsInfo.partitions)
fsInfo.addSystemRootLabel(mounts)
return fsInfo, nil
}
// getDockerDeviceMapperInfo returns information about the devicemapper device and "partition" if
// docker is using devicemapper for its storage driver. If a loopback device is being used, don't
// return any information or error, as we want to report based on the actual partition where the
// loopback file resides, inside of the loopback file itself.
func (self *RealFsInfo) getDockerDeviceMapperInfo(context DockerContext) (string, *partition, error) {
if context.Driver != DeviceMapper.String() {
return "", nil, nil
}
dataLoopFile := context.DriverStatus[dockerutil.DriverStatusDataLoopFile]
if len(dataLoopFile) > 0 {
return "", nil, nil
}
dev, major, minor, blockSize, err := dockerDMDevice(context.DriverStatus, self.dmsetup)
if err != nil {
return "", nil, err
}
return dev, &partition{
fsType: DeviceMapper.String(),
major: major,
minor: minor,
blockSize: blockSize,
}, nil
}
// addSystemRootLabel attempts to determine which device contains the mount for /.
func (self *RealFsInfo) addSystemRootLabel(mounts []*mount.Info) {
for _, m := range mounts {
if m.Mountpoint == "/" {
self.partitions[m.Source] = partition{
fsType: m.Fstype,
mountpoint: m.Mountpoint,
major: uint(m.Major),
minor: uint(m.Minor),
}
self.labels[LabelSystemRoot] = m.Source
return
}
}
}
// addDockerImagesLabel attempts to determine which device contains the mount for docker images.
func (self *RealFsInfo) addDockerImagesLabel(context Context, mounts []*mount.Info) {
dockerDev, dockerPartition, err := self.getDockerDeviceMapperInfo(context.Docker)
if err != nil {
glog.Warningf("Could not get Docker devicemapper device: %v", err)
}
if len(dockerDev) > 0 && dockerPartition != nil {
self.partitions[dockerDev] = *dockerPartition
self.labels[LabelDockerImages] = dockerDev
} else {
self.updateContainerImagesPath(LabelDockerImages, mounts, getDockerImagePaths(context))
}
}
func (self *RealFsInfo) addRktImagesLabel(context Context, mounts []*mount.Info) {
if context.RktPath != "" {
rktPath := context.RktPath
rktImagesPaths := map[string]struct{}{
"/": {},
}
for rktPath != "/" && rktPath != "." {
rktImagesPaths[rktPath] = struct{}{}
rktPath = filepath.Dir(rktPath)
}
self.updateContainerImagesPath(LabelRktImages, mounts, rktImagesPaths)
}
}
// Generate a list of possible mount points for docker image management from the docker root directory.
// Right now, we look for each type of supported graph driver directories, but we can do better by parsing
// some of the context from `docker info`.
func getDockerImagePaths(context Context) map[string]struct{} {
dockerImagePaths := map[string]struct{}{
"/": {},
}
// TODO(rjnagal): Detect docker root and graphdriver directories from docker info.
dockerRoot := context.Docker.Root
for _, dir := range []string{"devicemapper", "btrfs", "aufs", "overlay", "zfs"} {
dockerImagePaths[path.Join(dockerRoot, dir)] = struct{}{}
}
for dockerRoot != "/" && dockerRoot != "." {
dockerImagePaths[dockerRoot] = struct{}{}
dockerRoot = filepath.Dir(dockerRoot)
}
return dockerImagePaths
}
// This method compares the mountpoints with possible container image mount points. If a match is found,
// the label is added to the partition.
func (self *RealFsInfo) updateContainerImagesPath(label string, mounts []*mount.Info, containerImagePaths map[string]struct{}) {
var useMount *mount.Info
for _, m := range mounts {
if _, ok := containerImagePaths[m.Mountpoint]; ok {
if useMount == nil || (len(useMount.Mountpoint) < len(m.Mountpoint)) {
useMount = m
}
}
}
if useMount != nil {
self.partitions[useMount.Source] = partition{
fsType: useMount.Fstype,
mountpoint: useMount.Mountpoint,
major: uint(useMount.Major),
minor: uint(useMount.Minor),
}
self.labels[label] = useMount.Source
}
}
func (self *RealFsInfo) GetDeviceForLabel(label string) (string, error) {
dev, ok := self.labels[label]
if !ok {
return "", fmt.Errorf("non-existent label %q", label)
}
return dev, nil
}
func (self *RealFsInfo) GetLabelsForDevice(device string) ([]string, error) {
labels := []string{}
for label, dev := range self.labels {
if dev == device {
labels = append(labels, label)
}
}
return labels, nil
}
func (self *RealFsInfo) GetMountpointForDevice(dev string) (string, error) {
p, ok := self.partitions[dev]
if !ok {
return "", fmt.Errorf("no partition info for device %q", dev)
}
return p.mountpoint, nil
}
func (self *RealFsInfo) GetFsInfoForPath(mountSet map[string]struct{}) ([]Fs, error) {
filesystems := make([]Fs, 0)
deviceSet := make(map[string]struct{})
diskStatsMap, err := getDiskStatsMap("/proc/diskstats")
if err != nil {
return nil, err
}
for device, partition := range self.partitions {
_, hasMount := mountSet[partition.mountpoint]
_, hasDevice := deviceSet[device]
if mountSet == nil || (hasMount && !hasDevice) {
var (
err error
fs Fs
)
switch partition.fsType {
case DeviceMapper.String():
fs.Capacity, fs.Free, fs.Available, err = getDMStats(device, partition.blockSize)
glog.V(5).Infof("got devicemapper fs capacity stats: capacity: %v free: %v available: %v:", fs.Capacity, fs.Free, fs.Available)
fs.Type = DeviceMapper
case ZFS.String():
fs.Capacity, fs.Free, fs.Available, err = getZfstats(device)
fs.Type = ZFS
default:
fs.Capacity, fs.Free, fs.Available, fs.Inodes, fs.InodesFree, err = getVfsStats(partition.mountpoint)
fs.Type = VFS
}
if err != nil {
glog.Errorf("Stat fs failed. Error: %v", err)
} else {
deviceSet[device] = struct{}{}
fs.DeviceInfo = DeviceInfo{
Device: device,
Major: uint(partition.major),
Minor: uint(partition.minor),
}
fs.DiskStats = diskStatsMap[device]
filesystems = append(filesystems, fs)
}
}
}
return filesystems, nil
}
var partitionRegex = regexp.MustCompile(`^(?:(?:s|xv)d[a-z]+\d*|dm-\d+)$`)
func getDiskStatsMap(diskStatsFile string) (map[string]DiskStats, error) {
diskStatsMap := make(map[string]DiskStats)
file, err := os.Open(diskStatsFile)
if err != nil {
if os.IsNotExist(err) {
glog.Infof("not collecting filesystem statistics because file %q was not available", diskStatsFile)
return diskStatsMap, nil
}
return nil, err
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
words := strings.Fields(line)
if !partitionRegex.MatchString(words[2]) {
continue
}
// 8 50 sdd2 40 0 280 223 7 0 22 108 0 330 330
deviceName := path.Join("/dev", words[2])
wordLength := len(words)
offset := 3
var stats = make([]uint64, wordLength-offset)
if len(stats) < 11 {
return nil, fmt.Errorf("could not parse all 11 columns of /proc/diskstats")
}
var error error
for i := offset; i < wordLength; i++ {
stats[i-offset], error = strconv.ParseUint(words[i], 10, 64)
if error != nil {
return nil, error
}
}
diskStats := DiskStats{
ReadsCompleted: stats[0],
ReadsMerged: stats[1],
SectorsRead: stats[2],
ReadTime: stats[3],
WritesCompleted: stats[4],
WritesMerged: stats[5],
SectorsWritten: stats[6],
WriteTime: stats[7],
IoInProgress: stats[8],
IoTime: stats[9],
WeightedIoTime: stats[10],
}
diskStatsMap[deviceName] = diskStats
}
return diskStatsMap, nil
}
func (self *RealFsInfo) GetGlobalFsInfo() ([]Fs, error) {
return self.GetFsInfoForPath(nil)
}
func major(devNumber uint64) uint {
return uint((devNumber >> 8) & 0xfff)
}
func minor(devNumber uint64) uint {
return uint((devNumber & 0xff) | ((devNumber >> 12) & 0xfff00))
}
func (self *RealFsInfo) GetDirFsDevice(dir string) (*DeviceInfo, error) {
buf := new(syscall.Stat_t)
err := syscall.Stat(dir, buf)
if err != nil {
return nil, fmt.Errorf("stat failed on %s with error: %s", dir, err)
}
major := major(buf.Dev)
minor := minor(buf.Dev)
for device, partition := range self.partitions {
if partition.major == major && partition.minor == minor {
return &DeviceInfo{device, major, minor}, nil
}
}
return nil, fmt.Errorf("could not find device with major: %d, minor: %d in cached partitions map", major, minor)
}
func (self *RealFsInfo) GetDirUsage(dir string, timeout time.Duration) (uint64, error) {
if dir == "" {
return 0, fmt.Errorf("invalid directory")
}
claimDuToken()
defer releaseDuToken()
cmd := exec.Command("nice", "-n", "19", "du", "-s", dir)
stdoutp, err := cmd.StdoutPipe()
if err != nil {
return 0, fmt.Errorf("failed to setup stdout for cmd %v - %v", cmd.Args, err)
}
stderrp, err := cmd.StderrPipe()
if err != nil {
return 0, fmt.Errorf("failed to setup stderr for cmd %v - %v", cmd.Args, err)
}
if err := cmd.Start(); err != nil {
return 0, fmt.Errorf("failed to exec du - %v", err)
}
stdoutb, souterr := ioutil.ReadAll(stdoutp)
stderrb, _ := ioutil.ReadAll(stderrp)
timer := time.AfterFunc(timeout, func() {
glog.Infof("killing cmd %v due to timeout(%s)", cmd.Args, timeout.String())
cmd.Process.Kill()
})
err = cmd.Wait()
timer.Stop()
if err != nil {
return 0, fmt.Errorf("du command failed on %s with output stdout: %s, stderr: %s - %v", dir, string(stdoutb), string(stderrb), err)
}
stdout := string(stdoutb)
if souterr != nil {
glog.Errorf("failed to read from stdout for cmd %v - %v", cmd.Args, souterr)
}
usageInKb, err := strconv.ParseUint(strings.Fields(stdout)[0], 10, 64)
if err != nil {
return 0, fmt.Errorf("cannot parse 'du' output %s - %s", stdout, err)
}
return usageInKb * 1024, nil
}
func getVfsStats(path string) (total uint64, free uint64, avail uint64, inodes uint64, inodesFree uint64, err error) {
var s syscall.Statfs_t
if err = syscall.Statfs(path, &s); err != nil {
return 0, 0, 0, 0, 0, err
}
total = uint64(s.Frsize) * s.Blocks
free = uint64(s.Frsize) * s.Bfree
avail = uint64(s.Frsize) * s.Bavail
inodes = uint64(s.Files)
inodesFree = uint64(s.Ffree)
return total, free, avail, inodes, inodesFree, nil
}
// Devicemapper thin provisioning is detailed at
// https://www.kernel.org/doc/Documentation/device-mapper/thin-provisioning.txt
func dockerDMDevice(driverStatus map[string]string, dmsetup devicemapper.DmsetupClient) (string, uint, uint, uint, error) {
poolName, ok := driverStatus[dockerutil.DriverStatusPoolName]
if !ok || len(poolName) == 0 {
return "", 0, 0, 0, fmt.Errorf("Could not get dm pool name")
}
out, err := dmsetup.Table(poolName)
if err != nil {
return "", 0, 0, 0, err
}
major, minor, dataBlkSize, err := parseDMTable(string(out))
if err != nil {
return "", 0, 0, 0, err
}
return poolName, major, minor, dataBlkSize, nil
}
// parseDMTable parses a single line of `dmsetup table` output and returns the
// major device, minor device, block size, and an error.
func parseDMTable(dmTable string) (uint, uint, uint, error) {
dmTable = strings.Replace(dmTable, ":", " ", -1)
dmFields := strings.Fields(dmTable)
if len(dmFields) < 8 {
return 0, 0, 0, fmt.Errorf("Invalid dmsetup status output: %s", dmTable)
}
major, err := strconv.ParseUint(dmFields[5], 10, 32)
if err != nil {
return 0, 0, 0, err
}
minor, err := strconv.ParseUint(dmFields[6], 10, 32)
if err != nil {
return 0, 0, 0, err
}
dataBlkSize, err := strconv.ParseUint(dmFields[7], 10, 32)
if err != nil {
return 0, 0, 0, err
}
return uint(major), uint(minor), uint(dataBlkSize), nil
}
func getDMStats(poolName string, dataBlkSize uint) (uint64, uint64, uint64, error) {
out, err := exec.Command("dmsetup", "status", poolName).Output()
if err != nil {
return 0, 0, 0, err
}
used, total, err := parseDMStatus(string(out))
if err != nil {
return 0, 0, 0, err
}
used *= 512 * uint64(dataBlkSize)
total *= 512 * uint64(dataBlkSize)
free := total - used
return total, free, free, nil
}
func parseDMStatus(dmStatus string) (uint64, uint64, error) {
dmStatus = strings.Replace(dmStatus, "/", " ", -1)
dmFields := strings.Fields(dmStatus)
if len(dmFields) < 8 {
return 0, 0, fmt.Errorf("Invalid dmsetup status output: %s", dmStatus)
}
used, err := strconv.ParseUint(dmFields[6], 10, 64)
if err != nil {
return 0, 0, err
}
total, err := strconv.ParseUint(dmFields[7], 10, 64)
if err != nil {
return 0, 0, err
}
return used, total, nil
}
// getZfstats returns ZFS mount stats using zfsutils
func getZfstats(poolName string) (uint64, uint64, uint64, error) {
dataset, err := zfs.GetDataset(poolName)
if err != nil {
return 0, 0, 0, err
}
total := dataset.Used + dataset.Avail + dataset.Usedbydataset
return total, dataset.Avail, dataset.Avail, nil
}