Merge pull request #7959 from crosbymichael/update-libcontainer-sep6

Update libcontainer to 84ad9386a0240acb7475429a835

hack/vendor.sh

@@ -62,7 +62,7 @@ if [ "$1" = '--go' ]; then
 	mv tmp-tar src/code.google.com/p/go/src/pkg/archive/tar
 fi
 
-clone git github.com/docker/libcontainer 55430d0db7c6bb1198c0bb573a9700a859d5ec26
+clone git github.com/docker/libcontainer 84ad9386a0240acb7475429a835d826007032bf9
 # see src/github.com/docker/libcontainer/update-vendor.sh which is the "source of truth" for libcontainer deps (just like this file)
 rm -rf src/github.com/docker/libcontainer/vendor
 eval "$(grep '^clone ' src/github.com/docker/libcontainer/update-vendor.sh | grep -v 'github.com/codegangsta/cli')"

vendor/src/github.com/docker/libcontainer/cgroups/fs/cpuacct.go

@@ -1,26 +1,22 @@
 package fs
 
 import (
-	"bufio"
 	"fmt"
 	"io/ioutil"
-	"os"
 	"path/filepath"
-	"runtime"
 	"strconv"
 	"strings"
-	"time"
 
 	"github.com/docker/libcontainer/cgroups"
 	"github.com/docker/libcontainer/system"
 )
 
-var (
-	cpuCount   = uint64(runtime.NumCPU())
-	clockTicks = uint64(system.GetClockTicks())
+const (
+	cgroupCpuacctStat   = "cpuacct.stat"
+	nanosecondsInSecond = 1000000000
 )
 
-const nanosecondsInSecond = 1000000000
+var clockTicks = uint64(system.GetClockTicks())
 
 type CpuacctGroup struct {
 }
@@ -39,103 +35,53 @@ func (s *CpuacctGroup) Remove(d *data) error {
 }
 
 func (s *CpuacctGroup) GetStats(path string, stats *cgroups.Stats) error {
-	var (
-		err                                                                                                           error
-		startCpu, lastCpu, startSystem, lastSystem, startUsage, lastUsage, kernelModeUsage, userModeUsage, percentage uint64
-	)
-	if kernelModeUsage, userModeUsage, err = getCpuUsage(path); err != nil {
-		return err
-	}
-	startCpu = kernelModeUsage + userModeUsage
-	if startSystem, err = getSystemCpuUsage(); err != nil {
-		return err
-	}
-	startUsageTime := time.Now()
-	if startUsage, err = getCgroupParamInt(path, "cpuacct.usage"); err != nil {
-		return err
-	}
-	// sample for 100ms
-	time.Sleep(1000 * time.Millisecond)
-	if kernelModeUsage, userModeUsage, err = getCpuUsage(path); err != nil {
-		return err
-	}
-	lastCpu = kernelModeUsage + userModeUsage
-	if lastSystem, err = getSystemCpuUsage(); err != nil {
+	userModeUsage, kernelModeUsage, err := getCpuUsageBreakdown(path)
+	if err != nil {
 		return err
 	}
-	usageSampleDuration := time.Since(startUsageTime)
-	if lastUsage, err = getCgroupParamInt(path, "cpuacct.usage"); err != nil {
+
+	totalUsage, err := getCgroupParamInt(path, "cpuacct.usage")
+	if err != nil {
 		return err
 	}
 
-	var (
-		deltaProc   = lastCpu - startCpu
-		deltaSystem = lastSystem - startSystem
-		deltaUsage  = lastUsage - startUsage
-	)
-	if deltaSystem > 0.0 {
-		percentage = uint64((float64(deltaProc) / float64(deltaSystem)) * float64(clockTicks*cpuCount))
-	}
-	// NOTE: a percentage over 100% is valid for POSIX because that means the
-	// processes is using multiple cores
-	stats.CpuStats.CpuUsage.PercentUsage = percentage
-	// Delta usage is in nanoseconds of CPU time so get the usage (in cores) over the sample time.
-	stats.CpuStats.CpuUsage.CurrentUsage = deltaUsage / uint64(usageSampleDuration.Nanoseconds())
 	percpuUsage, err := getPercpuUsage(path)
 	if err != nil {
 		return err
 	}
-	stats.CpuStats.CpuUsage.TotalUsage = lastUsage
+
+	stats.CpuStats.CpuUsage.TotalUsage = totalUsage
 	stats.CpuStats.CpuUsage.PercpuUsage = percpuUsage
-	stats.CpuStats.CpuUsage.UsageInKernelmode = (kernelModeUsage * nanosecondsInSecond) / clockTicks
-	stats.CpuStats.CpuUsage.UsageInUsermode = (userModeUsage * nanosecondsInSecond) / clockTicks
+	stats.CpuStats.CpuUsage.UsageInUsermode = userModeUsage
+	stats.CpuStats.CpuUsage.UsageInKernelmode = kernelModeUsage
 	return nil
 }
 
-// TODO(vmarmol): Use cgroups stats.
-func getSystemCpuUsage() (uint64, error) {
-
-	f, err := os.Open("/proc/stat")
-	if err != nil {
-		return 0, err
-	}
-	defer f.Close()
-
-	sc := bufio.NewScanner(f)
-	for sc.Scan() {
-		parts := strings.Fields(sc.Text())
-		switch parts[0] {
-		case "cpu":
-			if len(parts) < 8 {
-				return 0, fmt.Errorf("invalid number of cpu fields")
-			}
-
-			var total uint64
-			for _, i := range parts[1:8] {
-				v, err := strconv.ParseUint(i, 10, 64)
-				if err != nil {
-					return 0.0, fmt.Errorf("Unable to convert value %s to int: %s", i, err)
-				}
-				total += v
-			}
-			return total, nil
-		default:
-			continue
-		}
-	}
-	return 0, fmt.Errorf("invalid stat format")
-}
-
-func getCpuUsage(path string) (uint64, uint64, error) {
-	kernelModeUsage := uint64(0)
+// Returns user and kernel usage breakdown in nanoseconds.
+func getCpuUsageBreakdown(path string) (uint64, uint64, error) {
 	userModeUsage := uint64(0)
-	data, err := ioutil.ReadFile(filepath.Join(path, "cpuacct.stat"))
+	kernelModeUsage := uint64(0)
+	const (
+		userField   = "user"
+		systemField = "system"
+	)
+
+	// Expected format:
+	// user <usage in ticks>
+	// system <usage in ticks>
+	data, err := ioutil.ReadFile(filepath.Join(path, cgroupCpuacctStat))
 	if err != nil {
 		return 0, 0, err
 	}
 	fields := strings.Fields(string(data))
 	if len(fields) != 4 {
-		return 0, 0, fmt.Errorf("Failure - %s is expected to have 4 fields", filepath.Join(path, "cpuacct.stat"))
+		return 0, 0, fmt.Errorf("failure - %s is expected to have 4 fields", filepath.Join(path, cgroupCpuacctStat))
+	}
+	if fields[0] != userField {
+		return 0, 0, fmt.Errorf("unexpected field %q in %q, expected %q", fields[0], cgroupCpuacctStat, userField)
+	}
+	if fields[2] != systemField {
+		return 0, 0, fmt.Errorf("unexpected field %q in %q, expected %q", fields[2], cgroupCpuacctStat, systemField)
 	}
 	if userModeUsage, err = strconv.ParseUint(fields[1], 10, 64); err != nil {
 		return 0, 0, err
@@ -144,7 +90,7 @@ func getCpuUsage(path string) (uint64, uint64, error) {
 		return 0, 0, err
 	}
 
-	return kernelModeUsage, userModeUsage, nil
+	return (userModeUsage * nanosecondsInSecond) / clockTicks, (kernelModeUsage * nanosecondsInSecond) / clockTicks, nil
 }
 
 func getPercpuUsage(path string) ([]uint64, error) {

vendor/src/github.com/docker/libcontainer/cgroups/stats.go

@@ -9,17 +9,19 @@ type ThrottlingData struct {
 	ThrottledTime uint64 `json:"throttled_time,omitempty"`
 }
 
+// All CPU stats are aggregate since container inception.
 type CpuUsage struct {
-	// percentage of available CPUs currently being used.
-	PercentUsage uint64 `json:"percent_usage,omitempty"`
-	// nanoseconds of cpu time consumed over the last 100 ms.
-	CurrentUsage uint64 `json:"current_usage,omitempty"`
-	// total nanoseconds of cpu time consumed
-	TotalUsage  uint64   `json:"total_usage,omitempty"`
+	// Total CPU time consumed.
+	// Units: nanoseconds.
+	TotalUsage uint64 `json:"total_usage,omitempty"`
+	// Total CPU time consumed per core.
+	// Units: nanoseconds.
 	PercpuUsage []uint64 `json:"percpu_usage,omitempty"`
-	// Time spent by tasks of the cgroup in kernel mode. Units: nanoseconds.
+	// Time spent by tasks of the cgroup in kernel mode.
+	// Units: nanoseconds.
 	UsageInKernelmode uint64 `json:"usage_in_kernelmode"`
-	// Time spent by tasks of the cgroup in user mode. Units: nanoseconds.
+	// Time spent by tasks of the cgroup in user mode.
+	// Units: nanoseconds.
 	UsageInUsermode uint64 `json:"usage_in_usermode"`
 }
 

vendor/src/github.com/docker/libcontainer/devices/devices.go

@@ -24,6 +24,8 @@ type Device struct {
 	MinorNumber       int64       `json:"minor_number,omitempty"`       // Use the wildcard constant for wildcards.
 	CgroupPermissions string      `json:"cgroup_permissions,omitempty"` // Typically just "rwm"
 	FileMode          os.FileMode `json:"file_mode,omitempty"`          // The permission bits of the file's mode
+	Uid               uint32      `json:"uid,omitempty"`
+	Gid               uint32      `json:"gid,omitempty"`
 }
 
 func GetDeviceNumberString(deviceNumber int64) string {
@@ -75,6 +77,8 @@ func GetDevice(path, cgroupPermissions string) (*Device, error) {
 		MinorNumber:       Minor(devNumber),
 		CgroupPermissions: cgroupPermissions,
 		FileMode:          fileModePermissionBits,
+		Uid:               stat_t.Uid,
+		Gid:               stat_t.Gid,
 	}, nil
 }
 

vendor/src/github.com/docker/libcontainer/factory.go

@@ -1,14 +1,20 @@
 package libcontainer
 
 type Factory interface {
-	// Creates a new container in the given path. A unique ID is generated for the container and
-	// starts the initial process inside the container.
+
+	// Creates a new container with the given id and starts the initial process inside it.
+	// id must be a string containing only letters, digits and underscores and must contain
+	// between 1 and 1024 characters, inclusive.
+	//
+	// The id must not already be in use by an existing container. Containers created using
+	// a factory with the same path (and file system) must have distinct ids.
 	//
 	// Returns the new container with a running process.
 	//
 	// Errors:
-	// Path already exists
-	// Config or initialConfig is invalid
+	// id is already in use by a container
+	// id has incorrect format
+	// config is invalid
 	// System error
 	//
 	// On error, any partially created container parts are cleaned up (the operation is atomic).

vendor/src/github.com/docker/libcontainer/mount/mount.go

@@ -17,6 +17,7 @@ type Mount struct {
 	Writable    bool   `json:"writable,omitempty"`
 	Relabel     string `json:"relabel,omitempty"` // Relabel source if set, "z" indicates shared, "Z" indicates unshared
 	Private     bool   `json:"private,omitempty"`
+	Slave       bool   `json:"slave,omitempty"`
 }
 
 func (m *Mount) Mount(rootfs, mountLabel string) error {
@@ -40,6 +41,10 @@ func (m *Mount) bindMount(rootfs, mountLabel string) error {
 		flags = flags | syscall.MS_RDONLY
 	}
 
+	if m.Slave {
+		flags = flags | syscall.MS_SLAVE
+	}
+
 	stat, err := os.Stat(m.Source)
 	if err != nil {
 		return err

vendor/src/github.com/docker/libcontainer/mount/nodes/nodes.go

@@ -48,5 +48,10 @@ func CreateDeviceNode(rootfs string, node *devices.Device) error {
 	if err := syscall.Mknod(dest, uint32(fileMode), devices.Mkdev(node.MajorNumber, node.MinorNumber)); err != nil && !os.IsExist(err) {
 		return fmt.Errorf("mknod %s %s", node.Path, err)
 	}
+
+	if err := syscall.Chown(dest, int(node.Uid), int(node.Gid)); err != nil {
+		return fmt.Errorf("chown %s to %d:%d", node.Path, node.Uid, node.Gid)
+	}
+
 	return nil
 }

vendor/src/github.com/docker/libcontainer/syncpipe/sync_pipe.go

@@ -77,6 +77,10 @@ func (s *SyncPipe) ReadFromParent(v interface{}) error {
 }
 
 func (s *SyncPipe) ReportChildError(err error) {
+	// ensure that any data sent from the parent is consumed so it doesn't
+	// receive ECONNRESET when the child writes to the pipe.
+	ioutil.ReadAll(s.child)
+
 	s.child.Write([]byte(err.Error()))
 	s.CloseChild()
 }

vendor/src/github.com/docker/libcontainer/syncpipe/sync_pipe_test.go

@@ -2,6 +2,7 @@ package syncpipe
 
 import (
 	"fmt"
+	"syscall"
 	"testing"
 )
 
@@ -20,9 +21,17 @@ func TestSendErrorFromChild(t *testing.T) {
 		}
 	}()
 
-	expected := "something bad happened"
+	childfd, err := syscall.Dup(int(pipe.Child().Fd()))
+	if err != nil {
+		t.Fatal(err)
+	}
+	childPipe, _ := NewSyncPipeFromFd(0, uintptr(childfd))
+
+	pipe.CloseChild()
+	pipe.SendToChild(nil)
 
-	pipe.ReportChildError(fmt.Errorf(expected))
+	expected := "something bad happened"
+	childPipe.ReportChildError(fmt.Errorf(expected))
 
 	childError := pipe.ReadFromChild()
 	if childError == nil {