@@ -33,7 +33,6 @@ import (

 	"github.com/docker/docker/nat"

 	"github.com/docker/docker/opts"

 	"github.com/docker/docker/pkg/archive"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/fileutils"

 	"github.com/docker/docker/pkg/homedir"

 	flag "github.com/docker/docker/pkg/mflag"

@@ -43,6 +42,7 @@ import (

 	"github.com/docker/docker/pkg/promise"

 	"github.com/docker/docker/pkg/resolvconf"

 	"github.com/docker/docker/pkg/signal"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/symlink"

 	"github.com/docker/docker/pkg/term"

 	"github.com/docker/docker/pkg/timeutils"

@@ -1165,7 +1165,7 @@ func (cli *DockerCli) CmdHistory(args ...string) error {

 			if *noTrunc {

 				fmt.Fprintf(w, "%s\t", outID)

 			} else {

-				fmt.Fprintf(w, "%s\t", common.TruncateID(outID))

+				fmt.Fprintf(w, "%s\t", stringid.TruncateID(outID))

 			}

 			fmt.Fprintf(w, "%s ago\t", units.HumanDuration(time.Now().UTC().Sub(time.Unix(out.GetInt64("Created"), 0))))

@@ -1180,7 +1180,7 @@ func (cli *DockerCli) CmdHistory(args ...string) error {

 			if *noTrunc {

 				fmt.Fprintln(w, outID)

 			} else {

-				fmt.Fprintln(w, common.TruncateID(outID))

+				fmt.Fprintln(w, stringid.TruncateID(outID))

 			}

 		}

 	}

@@ -1479,7 +1479,7 @@ func (cli *DockerCli) CmdImages(args ...string) error {

 			}

 			if matchName != "" {

-				if matchName == image.Get("Id") || matchName == common.TruncateID(image.Get("Id")) {

+				if matchName == image.Get("Id") || matchName == stringid.TruncateID(image.Get("Id")) {

 					startImage = image

 				}

@@ -1549,7 +1549,7 @@ func (cli *DockerCli) CmdImages(args ...string) error {

 		for _, out := range outs.Data {

 			outID := out.Get("Id")

 			if !*noTrunc {

-				outID = common.TruncateID(outID)

+				outID = stringid.TruncateID(outID)

 			}

 			repoTags := out.GetList("RepoTags")

@@ -1629,8 +1629,8 @@ func (cli *DockerCli) printVizNode(noTrunc bool, image *engine.Env, prefix strin

 		imageID = image.Get("Id")

 		parentID = image.Get("ParentId")

 	} else {

-		imageID = common.TruncateID(image.Get("Id"))

-		parentID = common.TruncateID(image.Get("ParentId"))

+		imageID = stringid.TruncateID(image.Get("Id"))

+		parentID = stringid.TruncateID(image.Get("ParentId"))

 	}

 	if parentID == "" {

 		fmt.Fprintf(cli.out, " base -> \"%s\" [style=invis]\n", imageID)

@@ -1649,7 +1649,7 @@ func (cli *DockerCli) printTreeNode(noTrunc bool, image *engine.Env, prefix stri

 	if noTrunc {

 		imageID = image.Get("Id")

 	} else {

-		imageID = common.TruncateID(image.Get("Id"))

+		imageID = stringid.TruncateID(image.Get("Id"))

 	}

 	fmt.Fprintf(cli.out, "%s%s Virtual Size: %s", prefix, imageID, units.HumanSize(float64(image.GetInt64("VirtualSize"))))

@@ -1757,7 +1757,7 @@ func (cli *DockerCli) CmdPs(args ...string) error {

 		outID := out.Get("Id")

 		if !*noTrunc {

-			outID = common.TruncateID(outID)

+			outID = stringid.TruncateID(outID)

 		}

 		if *quiet {

@@ -32,8 +32,8 @@ import (

 	"github.com/docker/docker/builder/parser"

 	"github.com/docker/docker/daemon"

 	"github.com/docker/docker/engine"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/fileutils"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/symlink"

 	"github.com/docker/docker/pkg/tarsum"

 	"github.com/docker/docker/registry"

@@ -177,7 +177,7 @@ func (b *Builder) Run(context io.Reader) (string, error) {

 			}

 			return "", err

 		}

-		fmt.Fprintf(b.OutStream, " ---> %s\n", common.TruncateID(b.image))

+		fmt.Fprintf(b.OutStream, " ---> %s\n", stringid.TruncateID(b.image))

 		if b.Remove {

 			b.clearTmp()

 		}

@@ -187,7 +187,7 @@ func (b *Builder) Run(context io.Reader) (string, error) {

 		return "", fmt.Errorf("No image was generated. Is your Dockerfile empty?")

 	}

-	fmt.Fprintf(b.OutStream, "Successfully built %s\n", common.TruncateID(b.image))

+	fmt.Fprintf(b.OutStream, "Successfully built %s\n", stringid.TruncateID(b.image))

 	return b.image, nil

 }

@@ -25,10 +25,10 @@ import (

 	imagepkg "github.com/docker/docker/image"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/chrootarchive"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/ioutils"

 	"github.com/docker/docker/pkg/parsers"

 	"github.com/docker/docker/pkg/progressreader"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/symlink"

 	"github.com/docker/docker/pkg/system"

 	"github.com/docker/docker/pkg/tarsum"

@@ -557,7 +557,7 @@ func (b *Builder) create() (*daemon.Container, error) {

 	}

 	b.TmpContainers[c.ID] = struct{}{}

-	fmt.Fprintf(b.OutStream, " ---> Running in %s\n", common.TruncateID(c.ID))

+	fmt.Fprintf(b.OutStream, " ---> Running in %s\n", stringid.TruncateID(c.ID))

 	if len(config.Cmd) > 0 {

 		// override the entry point that may have been picked up from the base image

@@ -753,11 +753,11 @@ func (b *Builder) clearTmp() {

 		}

 		if err := b.Daemon.Rm(tmp); err != nil {

-			fmt.Fprintf(b.OutStream, "Error removing intermediate container %s: %v\n", common.TruncateID(c), err)

+			fmt.Fprintf(b.OutStream, "Error removing intermediate container %s: %v\n", stringid.TruncateID(c), err)

 			return

 		}

 		b.Daemon.DeleteVolumes(tmp.VolumePaths())

 		delete(b.TmpContainers, c)

-		fmt.Fprintf(b.OutStream, "Removing intermediate container %s\n", common.TruncateID(c))

+		fmt.Fprintf(b.OutStream, "Removing intermediate container %s\n", stringid.TruncateID(c))

 	}

 }

@@ -30,12 +30,12 @@ import (

 	"github.com/docker/docker/nat"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/broadcastwriter"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/directory"

 	"github.com/docker/docker/pkg/etchosts"

 	"github.com/docker/docker/pkg/ioutils"

 	"github.com/docker/docker/pkg/promise"

 	"github.com/docker/docker/pkg/resolvconf"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/symlink"

 	"github.com/docker/docker/pkg/ulimit"

 	"github.com/docker/docker/runconfig"

@@ -739,7 +739,7 @@ func (container *Container) Kill() error {

 	if _, err := container.WaitStop(10 * time.Second); err != nil {

 		// Ensure that we don't kill ourselves

 		if pid := container.GetPid(); pid != 0 {

-			log.Infof("Container %s failed to exit within 10 seconds of kill - trying direct SIGKILL", common.TruncateID(container.ID))

+			log.Infof("Container %s failed to exit within 10 seconds of kill - trying direct SIGKILL", stringid.TruncateID(container.ID))

 			if err := syscall.Kill(pid, 9); err != nil {

 				if err != syscall.ESRCH {

 					return err

@@ -31,13 +31,13 @@ import (

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/broadcastwriter"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/graphdb"

 	"github.com/docker/docker/pkg/ioutils"

 	"github.com/docker/docker/pkg/namesgenerator"

 	"github.com/docker/docker/pkg/parsers"

 	"github.com/docker/docker/pkg/parsers/kernel"

 	"github.com/docker/docker/pkg/resolvconf"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/sysinfo"

 	"github.com/docker/docker/pkg/truncindex"

 	"github.com/docker/docker/runconfig"

@@ -517,7 +517,7 @@ func (daemon *Daemon) mergeAndVerifyConfig(config *runconfig.Config, img *image.

 func (daemon *Daemon) generateIdAndName(name string) (string, string, error) {

 	var (

 		err error

-		id  = common.GenerateRandomID()

+		id  = stringid.GenerateRandomID()

 	)

 	if name == "" {

@@ -562,7 +562,7 @@ func (daemon *Daemon) reserveName(id, name string) (string, error) {

 			nameAsKnownByUser := strings.TrimPrefix(name, "/")

 			return "", fmt.Errorf(

 				"Conflict. The name %q is already in use by container %s. You have to delete (or rename) that container to be able to reuse that name.", nameAsKnownByUser,

-				common.TruncateID(conflictingContainer.ID))

+				stringid.TruncateID(conflictingContainer.ID))

 		}

 	}

 	return name, nil

@@ -585,7 +585,7 @@ func (daemon *Daemon) generateNewName(id string) (string, error) {

 		return name, nil

 	}

-	name = "/" + common.TruncateID(id)

+	name = "/" + stringid.TruncateID(id)

 	if _, err := daemon.containerGraph.Set(name, id); err != nil {

 		return "", err

 	}

@@ -12,9 +12,9 @@ import (

 	"github.com/docker/docker/daemon/execdriver/lxc"

 	"github.com/docker/docker/engine"

 	"github.com/docker/docker/pkg/broadcastwriter"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/ioutils"

 	"github.com/docker/docker/pkg/promise"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/runconfig"

 )

@@ -141,7 +141,7 @@ func (d *Daemon) ContainerExecCreate(job *engine.Job) engine.Status {

 	}

 	execConfig := &execConfig{

-		ID:            common.GenerateRandomID(),

+		ID:            stringid.GenerateRandomID(),

 		OpenStdin:     config.AttachStdin,

 		OpenStdout:    config.AttachStdout,

 		OpenStderr:    config.AttachStderr,

@@ -34,9 +34,9 @@ import (

 	"github.com/docker/docker/daemon/graphdriver"

 	"github.com/docker/docker/pkg/archive"

 	"github.com/docker/docker/pkg/chrootarchive"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/directory"

 	mountpk "github.com/docker/docker/pkg/mount"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/libcontainer/label"

 )

@@ -405,7 +405,7 @@ func (a *Driver) Cleanup() error {

 	for _, id := range ids {

 		if err := a.unmount(id); err != nil {

-			log.Errorf("Unmounting %s: %s", common.TruncateID(id), err)

+			log.Errorf("Unmounting %s: %s", stringid.TruncateID(id), err)

 		}

 	}

@@ -7,8 +7,8 @@ import (

 	"github.com/docker/docker/engine"

 	"github.com/docker/docker/graph"

 	"github.com/docker/docker/image"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/parsers"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/utils"

 )

@@ -148,11 +148,11 @@ func (daemon *Daemon) canDeleteImage(imgID string, force bool) error {

 			if imgID == p.ID {

 				if container.IsRunning() {

 					if force {

-						return fmt.Errorf("Conflict, cannot force delete %s because the running container %s is using it, stop it and retry", common.TruncateID(imgID), common.TruncateID(container.ID))

+						return fmt.Errorf("Conflict, cannot force delete %s because the running container %s is using it, stop it and retry", stringid.TruncateID(imgID), stringid.TruncateID(container.ID))

 					}

-					return fmt.Errorf("Conflict, cannot delete %s because the running container %s is using it, stop it and use -f to force", common.TruncateID(imgID), common.TruncateID(container.ID))

+					return fmt.Errorf("Conflict, cannot delete %s because the running container %s is using it, stop it and use -f to force", stringid.TruncateID(imgID), stringid.TruncateID(container.ID))

 				} else if !force {

-					return fmt.Errorf("Conflict, cannot delete %s because the container %s is using it, use -f to force", common.TruncateID(imgID), common.TruncateID(container.ID))

+					return fmt.Errorf("Conflict, cannot delete %s because the container %s is using it, use -f to force", stringid.TruncateID(imgID), stringid.TruncateID(container.ID))

 				}

 			}

 			return nil

@@ -8,7 +8,7 @@ import (

 	log "github.com/Sirupsen/logrus"

 	"github.com/docker/docker/daemon/execdriver"

-	"github.com/docker/docker/pkg/common"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/runconfig"

 )

@@ -230,7 +230,7 @@ func (m *containerMonitor) shouldRestart(exitCode int) bool {

 		// the default value of 0 for MaximumRetryCount means that we will not enforce a maximum count

 		if max := m.restartPolicy.MaximumRetryCount; max != 0 && m.failureCount > max {

 			log.Debugf("stopping restart of container %s because maximum failure could of %d has been reached",

-				common.TruncateID(m.container.ID), max)

+				stringid.TruncateID(m.container.ID), max)

 			return false

 		}

@@ -10,8 +10,8 @@ import (

 	"sync"

 	"time"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/ioutils"

+	"github.com/docker/docker/pkg/stringutils"

 )

 // Installer is a standard interface for objects which can "install" themselves

@@ -78,7 +78,7 @@ func (eng *Engine) RegisterCatchall(catchall Handler) {

 func New() *Engine {

 	eng := &Engine{

 		handlers: make(map[string]Handler),

-		id:       common.RandomString(),

+		id:       stringutils.GenerateRandomString(),

 		Stdout:   os.Stdout,

 		Stderr:   os.Stderr,

 		Stdin:    os.Stdin,

@@ -3,23 +3,11 @@ package engine

 import (

 	"bytes"

 	"encoding/json"

-	"math/rand"

 	"testing"

 	"time"

-)

-

-const chars = "abcdefghijklmnopqrstuvwxyz" +

-	"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +

-	"~!@#$%^&*()-_+={}[]\\|<,>.?/\"';:` "

-// RandomString returns random string of specified length

-func RandomString(length int) string {

-	res := make([]byte, length)

-	for i := 0; i < length; i++ {

-		res[i] = chars[rand.Intn(len(chars))]

-	}

-	return string(res)

-}

+	"github.com/docker/docker/pkg/stringutils"

+)

 func TestEnvLenZero(t *testing.T) {

 	env := &Env{}

@@ -197,7 +185,7 @@ func TestMultiMap(t *testing.T) {

 func testMap(l int) [][2]string {

 	res := make([][2]string, l)

 	for i := 0; i < l; i++ {

-		t := [2]string{RandomString(5), RandomString(20)}

+		t := [2]string{stringutils.GenerateRandomAsciiString(5), stringutils.GenerateRandomAsciiString(20)}

 		res[i] = t

 	}

 	return res

@@ -17,8 +17,8 @@ import (

 	"github.com/docker/docker/daemon/graphdriver"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/pkg/archive"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/progressreader"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/truncindex"

 	"github.com/docker/docker/runconfig"

 	"github.com/docker/docker/utils"

@@ -118,7 +118,7 @@ func (graph *Graph) Get(name string) (*image.Image, error) {

 // Create creates a new image and registers it in the graph.

 func (graph *Graph) Create(layerData archive.ArchiveReader, containerID, containerImage, comment, author string, containerConfig, config *runconfig.Config) (*image.Image, error) {

 	img := &image.Image{

-		ID:            common.GenerateRandomID(),

+		ID:            stringid.GenerateRandomID(),

 		Comment:       comment,

 		Created:       time.Now().UTC(),

 		DockerVersion: dockerversion.VERSION,

@@ -217,7 +217,7 @@ func (graph *Graph) TempLayerArchive(id string, sf *utils.StreamFormatter, outpu

 		Formatter: sf,

 		Size:      0,

 		NewLines:  false,

-		ID:        common.TruncateID(id),

+		ID:        stringid.TruncateID(id),

 		Action:    "Buffering to disk",

 	})

 	defer progressReader.Close()

@@ -226,7 +226,7 @@ func (graph *Graph) TempLayerArchive(id string, sf *utils.StreamFormatter, outpu

 // Mktemp creates a temporary sub-directory inside the graph's filesystem.

 func (graph *Graph) Mktemp(id string) (string, error) {

-	dir := path.Join(graph.Root, "_tmp", common.GenerateRandomID())

+	dir := path.Join(graph.Root, "_tmp", stringid.GenerateRandomID())

 	if err := os.MkdirAll(dir, 0700); err != nil {

 		return "", err

 	}

@@ -14,8 +14,8 @@ import (

 	"github.com/docker/distribution/digest"

 	"github.com/docker/docker/engine"

 	"github.com/docker/docker/image"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/progressreader"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/registry"

 	"github.com/docker/docker/utils"

 )

@@ -172,9 +172,9 @@ func (s *TagStore) pullRepository(r *registry.Session, out io.Writer, repoInfo *

 			// ensure no two downloads of the same image happen at the same time

 			if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {

 				if c != nil {

-					out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))

 					<-c

-					out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Download complete", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))

 				} else {

 					log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)

 				}

@@ -185,12 +185,12 @@ func (s *TagStore) pullRepository(r *registry.Session, out io.Writer, repoInfo *

 			}

 			defer s.poolRemove("pull", "img:"+img.ID)

-			out.Write(sf.FormatProgress(common.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s", img.Tag, repoInfo.CanonicalName), nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s", img.Tag, repoInfo.CanonicalName), nil))

 			success := false

 			var lastErr, err error

 			var is_downloaded bool

 			for _, ep := range repoInfo.Index.Mirrors {

-				out.Write(sf.FormatProgress(common.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, mirror: %s", img.Tag, repoInfo.CanonicalName, ep), nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, mirror: %s", img.Tag, repoInfo.CanonicalName, ep), nil))

 				if is_downloaded, err = s.pullImage(r, out, img.ID, ep, repoData.Tokens, sf); err != nil {

 					// Don't report errors when pulling from mirrors.

 					log.Debugf("Error pulling image (%s) from %s, mirror: %s, %s", img.Tag, repoInfo.CanonicalName, ep, err)

@@ -202,12 +202,12 @@ func (s *TagStore) pullRepository(r *registry.Session, out io.Writer, repoInfo *

 			}

 			if !success {

 				for _, ep := range repoData.Endpoints {

-					out.Write(sf.FormatProgress(common.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, endpoint: %s", img.Tag, repoInfo.CanonicalName, ep), nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, endpoint: %s", img.Tag, repoInfo.CanonicalName, ep), nil))

 					if is_downloaded, err = s.pullImage(r, out, img.ID, ep, repoData.Tokens, sf); err != nil {

 						// It's not ideal that only the last error is returned, it would be better to concatenate the errors.

 						// As the error is also given to the output stream the user will see the error.

 						lastErr = err

-						out.Write(sf.FormatProgress(common.TruncateID(img.ID), fmt.Sprintf("Error pulling image (%s) from %s, endpoint: %s, %s", img.Tag, repoInfo.CanonicalName, ep, err), nil))

+						out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), fmt.Sprintf("Error pulling image (%s) from %s, endpoint: %s, %s", img.Tag, repoInfo.CanonicalName, ep, err), nil))

 						continue

 					}

 					layers_downloaded = layers_downloaded || is_downloaded

@@ -217,13 +217,13 @@ func (s *TagStore) pullRepository(r *registry.Session, out io.Writer, repoInfo *

 			}

 			if !success {

 				err := fmt.Errorf("Error pulling image (%s) from %s, %v", img.Tag, repoInfo.CanonicalName, lastErr)

-				out.Write(sf.FormatProgress(common.TruncateID(img.ID), err.Error(), nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), err.Error(), nil))

 				if parallel {

 					errors <- err

 					return

 				}

 			}

-			out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Download complete", nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))

 			if parallel {

 				errors <- nil

@@ -270,7 +270,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 	if err != nil {

 		return false, err

 	}

-	out.Write(sf.FormatProgress(common.TruncateID(imgID), "Pulling dependent layers", nil))

+	out.Write(sf.FormatProgress(stringid.TruncateID(imgID), "Pulling dependent layers", nil))

 	// FIXME: Try to stream the images?

 	// FIXME: Launch the getRemoteImage() in goroutines

@@ -286,7 +286,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 		defer s.poolRemove("pull", "layer:"+id)

 		if !s.graph.Exists(id) {

-			out.Write(sf.FormatProgress(common.TruncateID(id), "Pulling metadata", nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(id), "Pulling metadata", nil))

 			var (

 				imgJSON []byte

 				imgSize int

@@ -297,7 +297,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 			for j := 1; j <= retries; j++ {

 				imgJSON, imgSize, err = r.GetRemoteImageJSON(id, endpoint, token)

 				if err != nil && j == retries {

-					out.Write(sf.FormatProgress(common.TruncateID(id), "Error pulling dependent layers", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(id), "Error pulling dependent layers", nil))

 					return layers_downloaded, err

 				} else if err != nil {

 					time.Sleep(time.Duration(j) * 500 * time.Millisecond)

@@ -306,7 +306,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 				img, err = image.NewImgJSON(imgJSON)

 				layers_downloaded = true

 				if err != nil && j == retries {

-					out.Write(sf.FormatProgress(common.TruncateID(id), "Error pulling dependent layers", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(id), "Error pulling dependent layers", nil))

 					return layers_downloaded, fmt.Errorf("Failed to parse json: %s", err)

 				} else if err != nil {

 					time.Sleep(time.Duration(j) * 500 * time.Millisecond)

@@ -322,7 +322,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 				if j > 1 {

 					status = fmt.Sprintf("Pulling fs layer [retries: %d]", j)

 				}

-				out.Write(sf.FormatProgress(common.TruncateID(id), status, nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(id), status, nil))

 				layer, err := r.GetRemoteImageLayer(img.ID, endpoint, token, int64(imgSize))

 				if uerr, ok := err.(*url.Error); ok {

 					err = uerr.Err

@@ -331,7 +331,7 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 					time.Sleep(time.Duration(j) * 500 * time.Millisecond)

 					continue

 				} else if err != nil {

-					out.Write(sf.FormatProgress(common.TruncateID(id), "Error pulling dependent layers", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(id), "Error pulling dependent layers", nil))

 					return layers_downloaded, err

 				}

 				layers_downloaded = true

@@ -344,21 +344,21 @@ func (s *TagStore) pullImage(r *registry.Session, out io.Writer, imgID, endpoint

 						Formatter: sf,

 						Size:      imgSize,

 						NewLines:  false,

-						ID:        common.TruncateID(id),

+						ID:        stringid.TruncateID(id),

 						Action:    "Downloading",

 					}))

 				if terr, ok := err.(net.Error); ok && terr.Timeout() && j < retries {

 					time.Sleep(time.Duration(j) * 500 * time.Millisecond)

 					continue

 				} else if err != nil {

-					out.Write(sf.FormatProgress(common.TruncateID(id), "Error downloading dependent layers", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(id), "Error downloading dependent layers", nil))

 					return layers_downloaded, err

 				} else {

 					break

 				}

 			}

 		}

-		out.Write(sf.FormatProgress(common.TruncateID(id), "Download complete", nil))

+		out.Write(sf.FormatProgress(stringid.TruncateID(id), "Download complete", nil))

 	}

 	return layers_downloaded, nil

 }

@@ -478,16 +478,16 @@ func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Wri

 		}

 		downloads[i].digest = dgst

-		out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Pulling fs layer", nil))

+		out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Pulling fs layer", nil))

 		downloadFunc := func(di *downloadInfo) error {

 			log.Debugf("pulling blob %q to V1 img %s", sumStr, img.ID)

 			if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {

 				if c != nil {

-					out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))

 					<-c

-					out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Download complete", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))

 				} else {

 					log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)

 				}

@@ -515,20 +515,20 @@ func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Wri

 					Formatter: sf,

 					Size:      int(l),

 					NewLines:  false,

-					ID:        common.TruncateID(img.ID),

+					ID:        stringid.TruncateID(img.ID),

 					Action:    "Downloading",

 				})); err != nil {

 					return fmt.Errorf("unable to copy v2 image blob data: %s", err)

 				}

-				out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Verifying Checksum", nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Verifying Checksum", nil))

 				if !verifier.Verified() {

 					log.Infof("Image verification failed: checksum mismatch for %q", di.digest.String())

 					verified = false

 				}

-				out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Download complete", nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))

 				log.Debugf("Downloaded %s to tempfile %s", img.ID, tmpFile.Name())

 				di.tmpFile = tmpFile

@@ -574,7 +574,7 @@ func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Wri

 						Out:       out,

 						Formatter: sf,

 						Size:      int(d.length),

-						ID:        common.TruncateID(d.img.ID),

+						ID:        stringid.TruncateID(d.img.ID),

 						Action:    "Extracting",

 					}))

 				if err != nil {

@@ -583,10 +583,10 @@ func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Wri

 				// FIXME: Pool release here for parallel tag pull (ensures any downloads block until fully extracted)

 			}

-			out.Write(sf.FormatProgress(common.TruncateID(d.img.ID), "Pull complete", nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(d.img.ID), "Pull complete", nil))

 			tagUpdated = true

 		} else {

-			out.Write(sf.FormatProgress(common.TruncateID(d.img.ID), "Already exists", nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(d.img.ID), "Already exists", nil))

 		}

 	}

@@ -16,8 +16,8 @@ import (

 	"github.com/docker/distribution/digest"

 	"github.com/docker/docker/engine"

 	"github.com/docker/docker/image"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/progressreader"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/registry"

 	"github.com/docker/docker/runconfig"

 	"github.com/docker/docker/utils"

@@ -139,7 +139,7 @@ func lookupImageOnEndpoint(wg *sync.WaitGroup, r *registry.Session, out io.Write

 			imagesToPush <- image.id

 			continue

 		}

-		out.Write(sf.FormatStatus("", "Image %s already pushed, skipping", common.TruncateID(image.id)))

+		out.Write(sf.FormatStatus("", "Image %s already pushed, skipping", stringid.TruncateID(image.id)))

 	}

 }

@@ -191,7 +191,7 @@ func (s *TagStore) pushImageToEndpoint(endpoint string, out io.Writer, remoteNam

 			}

 		}

 		for _, tag := range tags[id] {

-			out.Write(sf.FormatStatus("", "Pushing tag for rev [%s] on {%s}", common.TruncateID(id), endpoint+"repositories/"+remoteName+"/tags/"+tag))

+			out.Write(sf.FormatStatus("", "Pushing tag for rev [%s] on {%s}", stringid.TruncateID(id), endpoint+"repositories/"+remoteName+"/tags/"+tag))

 			if err := r.PushRegistryTag(remoteName, id, tag, endpoint, repo.Tokens); err != nil {

 				return err

 			}

@@ -244,7 +244,7 @@ func (s *TagStore) pushImage(r *registry.Session, out io.Writer, imgID, ep strin

 	if err != nil {

 		return "", fmt.Errorf("Cannot retrieve the path for {%s}: %s", imgID, err)

 	}

-	out.Write(sf.FormatProgress(common.TruncateID(imgID), "Pushing", nil))

+	out.Write(sf.FormatProgress(stringid.TruncateID(imgID), "Pushing", nil))

 	imgData := &registry.ImgData{

 		ID: imgID,

@@ -253,7 +253,7 @@ func (s *TagStore) pushImage(r *registry.Session, out io.Writer, imgID, ep strin

 	// Send the json

 	if err := r.PushImageJSONRegistry(imgData, jsonRaw, ep, token); err != nil {

 		if err == registry.ErrAlreadyExists {

-			out.Write(sf.FormatProgress(common.TruncateID(imgData.ID), "Image already pushed, skipping", nil))

+			out.Write(sf.FormatProgress(stringid.TruncateID(imgData.ID), "Image already pushed, skipping", nil))

 			return "", nil

 		}

 		return "", err

@@ -275,7 +275,7 @@ func (s *TagStore) pushImage(r *registry.Session, out io.Writer, imgID, ep strin

 			Formatter: sf,

 			Size:      int(layerData.Size),

 			NewLines:  false,

-			ID:        common.TruncateID(imgData.ID),

+			ID:        stringid.TruncateID(imgData.ID),

 			Action:    "Pushing",

 		}), ep, token, jsonRaw)

 	if err != nil {

@@ -288,7 +288,7 @@ func (s *TagStore) pushImage(r *registry.Session, out io.Writer, imgID, ep strin

 		return "", err

 	}

-	out.Write(sf.FormatProgress(common.TruncateID(imgData.ID), "Image successfully pushed", nil))

+	out.Write(sf.FormatProgress(stringid.TruncateID(imgData.ID), "Image successfully pushed", nil))

 	return imgData.Checksum, nil

 }

@@ -385,7 +385,7 @@ func (s *TagStore) pushV2Repository(r *registry.Session, localRepo Repository, o

 				// Call mount blob

 				exists, err = r.HeadV2ImageBlob(endpoint, repoInfo.RemoteName, sumParts[0], sumParts[1], auth)

 				if err != nil {

-					out.Write(sf.FormatProgress(common.TruncateID(layer.ID), "Image push failed", nil))

+					out.Write(sf.FormatProgress(stringid.TruncateID(layer.ID), "Image push failed", nil))

 					return err

 				}

 			}

@@ -400,7 +400,7 @@ func (s *TagStore) pushV2Repository(r *registry.Session, localRepo Repository, o

 					checksum = cs

 				}

 			} else {

-				out.Write(sf.FormatProgress(common.TruncateID(layer.ID), "Image already exists", nil))

+				out.Write(sf.FormatProgress(stringid.TruncateID(layer.ID), "Image already exists", nil))

 			}

 			m.FSLayers[i] = &registry.FSLayer{BlobSum: checksum}

 			m.History[i] = &registry.ManifestHistory{V1Compatibility: string(jsonData)}

@@ -443,7 +443,7 @@ func (s *TagStore) pushV2Repository(r *registry.Session, localRepo Repository, o

 // PushV2Image pushes the image content to the v2 registry, first buffering the contents to disk

 func (s *TagStore) pushV2Image(r *registry.Session, img *image.Image, endpoint *registry.Endpoint, imageName string, sf *utils.StreamFormatter, out io.Writer, auth *registry.RequestAuthorization) (string, error) {

-	out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Buffering to Disk", nil))

+	out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Buffering to Disk", nil))

 	image, err := s.graph.Get(img.ID)

 	if err != nil {

@@ -481,13 +481,13 @@ func (s *TagStore) pushV2Image(r *registry.Session, img *image.Image, endpoint *

 			Formatter: sf,

 			Size:      int(size),

 			NewLines:  false,

-			ID:        common.TruncateID(img.ID),

+			ID:        stringid.TruncateID(img.ID),

 			Action:    "Pushing",

 		}), auth); err != nil {

-		out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Image push failed", nil))

+		out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Image push failed", nil))

 		return "", err

 	}

-	out.Write(sf.FormatProgress(common.TruncateID(img.ID), "Image successfully pushed", nil))

+	out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Image successfully pushed", nil))

 	return dgst.String(), nil

 }

@@ -13,8 +13,8 @@ import (

 	"sync"

 	"github.com/docker/docker/image"

-	"github.com/docker/docker/pkg/common"

 	"github.com/docker/docker/pkg/parsers"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/registry"

 	"github.com/docker/docker/utils"

 	"github.com/docker/libtrust"

@@ -163,7 +163,7 @@ func (store *TagStore) ImageName(id string) string {

 	if names, exists := store.ByID()[id]; exists && len(names) > 0 {

 		return names[0]

 	}

-	return common.TruncateID(id)

+	return stringid.TruncateID(id)

 }

 func (store *TagStore) DeleteAll(id string) error {

@@ -331,7 +331,7 @@ func (store *TagStore) GetRepoRefs() map[string][]string {

 	for name, repository := range store.Repositories {

 		for tag, id := range repository {

-			shortID := common.TruncateID(id)

+			shortID := stringid.TruncateID(id)

 			reporefs[shortID] = append(reporefs[shortID], utils.ImageReference(name, tag))

 		}

 	}

@@ -22,6 +22,7 @@ import (

 	"github.com/docker/docker/builder/command"

 	"github.com/docker/docker/pkg/archive"

+	"github.com/docker/docker/pkg/stringutils"

 )

 func TestBuildJSONEmptyRun(t *testing.T) {

@@ -4420,7 +4421,7 @@ func TestBuildOnBuildOutput(t *testing.T) {

 }

 func TestBuildInvalidTag(t *testing.T) {

-	name := "abcd:" + makeRandomString(200)

+	name := "abcd:" + stringutils.GenerateRandomAlphaOnlyString(200)

 	defer deleteImages(name)

 	_, out, err := buildImageWithOut(name, "FROM scratch\nMAINTAINER quux\n", true)

 	// if the error doesnt check for illegal tag name, or the image is built

@@ -9,7 +9,7 @@ import (

 	"testing"

 	"time"

-	"github.com/docker/docker/pkg/common"

+	"github.com/docker/docker/pkg/stringid"

 )

 func TestImagesEnsureImageIsListed(t *testing.T) {

@@ -196,7 +196,7 @@ func TestImagesEnsureDanglingImageOnlyListedOnce(t *testing.T) {

 	if err != nil {

 		t.Fatalf("error tagging foobox: %s", err)

 	}

-	imageId := common.TruncateID(strings.TrimSpace(out))

+	imageId := stringid.TruncateID(strings.TrimSpace(out))

 	defer deleteImages(imageId)

 	// overwrite the tag, making the previous image dangling

@@ -5,6 +5,8 @@ import (

 	"os/exec"

 	"strings"

 	"testing"

+

+	"github.com/docker/docker/pkg/stringutils"

 )

 // tagging a named image in a new unprefixed repo should work

@@ -59,7 +61,7 @@ func TestTagInvalidUnprefixedRepo(t *testing.T) {

 // ensure we don't allow the use of invalid tags; these tag operations should fail

 func TestTagInvalidPrefixedRepo(t *testing.T) {

-	long_tag := makeRandomString(121)

+	long_tag := stringutils.GenerateRandomAlphaOnlyString(121)

 	invalidTags := []string{"repo:fo$z$", "repo:Foo@3cc", "repo:Foo$3", "repo:Foo*3", "repo:Fo^3", "repo:Foo!3", "repo:%goodbye", "repo:#hashtagit", "repo:F)xcz(", "repo:-foo", "repo:..", long_tag}

@@ -22,6 +22,7 @@ import (

 	"time"

 	"github.com/docker/docker/api"

+	"github.com/docker/docker/pkg/stringutils"

 )

 // Daemon represents a Docker daemon for the testing framework.

@@ -695,8 +696,8 @@ func (f *remoteFileServer) Close() error {

 func newRemoteFileServer(ctx *FakeContext) (*remoteFileServer, error) {

 	var (

-		image     = fmt.Sprintf("fileserver-img-%s", strings.ToLower(makeRandomString(10)))

-		container = fmt.Sprintf("fileserver-cnt-%s", strings.ToLower(makeRandomString(10)))

+		image     = fmt.Sprintf("fileserver-img-%s", strings.ToLower(stringutils.GenerateRandomAlphaOnlyString(10)))

+		container = fmt.Sprintf("fileserver-cnt-%s", strings.ToLower(stringutils.GenerateRandomAlphaOnlyString(10)))

 	)

 	// Build the image

@@ -6,7 +6,6 @@ import (

 	"errors"

 	"fmt"

 	"io"

-	"math/rand"

 	"net/http"

 	"net/http/httptest"

 	"os"

@@ -17,6 +16,7 @@ import (

 	"syscall"

 	"time"

+	"github.com/docker/docker/pkg/stringutils"

 	"github.com/docker/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"

 )

@@ -301,21 +301,10 @@ func copyWithCP(source, target string) error {

 	return nil

 }

-func makeRandomString(n int) string {

-	// make a really long string

-	letters := []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

-	b := make([]byte, n)

-	r := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))

-	for i := range b {

-		b[i] = letters[r.Intn(len(letters))]

-	}

-	return string(b)

-}

-

 // randomUnixTmpDirPath provides a temporary unix path with rand string appended.

 // does not create or checks if it exists.

 func randomUnixTmpDirPath(s string) string {

-	return path.Join("/tmp", fmt.Sprintf("%s.%s", s, makeRandomString(10)))

+	return path.Join("/tmp", fmt.Sprintf("%s.%s", s, stringutils.GenerateRandomAlphaOnlyString(10)))

 }

 // Reads chunkSize bytes from reader after every interval.

@@ -12,7 +12,7 @@ import (

 	log "github.com/Sirupsen/logrus"

 	"github.com/docker/docker/api/client"

 	"github.com/docker/docker/daemon"

-	"github.com/docker/docker/pkg/common"

+	"github.com/docker/docker/pkg/stringid"

 	"github.com/docker/docker/pkg/term"

 	"github.com/kr/pty"

 )

@@ -286,7 +286,7 @@ func TestAttachDetachTruncatedID(t *testing.T) {

 	ch := make(chan struct{})

 	go func() {

 		defer close(ch)

-		if err := cli.CmdAttach(common.TruncateID(container.ID)); err != nil {

+		if err := cli.CmdAttach(stringid.TruncateID(container.ID)); err != nil {

 			if err != io.ErrClosedPipe {

 				t.Fatal(err)

 			}

@@ -2,19 +2,20 @@ package docker

 import (

 	"errors"

-	"github.com/docker/docker/autogen/dockerversion"

-	"github.com/docker/docker/daemon/graphdriver"

-	"github.com/docker/docker/graph"

-	"github.com/docker/docker/image"

-	"github.com/docker/docker/pkg/archive"

-	"github.com/docker/docker/pkg/common"

-	"github.com/docker/docker/utils"