moby/server.go

package docker

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/dotcloud/docker/archive"
	"github.com/dotcloud/docker/auth"
	"github.com/dotcloud/docker/cgroups"
	"github.com/dotcloud/docker/engine"
	"github.com/dotcloud/docker/pkg/graphdb"
	"github.com/dotcloud/docker/registry"
	"github.com/dotcloud/docker/utils"
	"io"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"os"
	"os/exec"
	"os/signal"
	"path"
	"path/filepath"
	"runtime"
	"strconv"
	"strings"
	"sync"
	"syscall"
	"time"
)

func (srv *Server) Close() error {
	return srv.runtime.Close()
}

func init() {
	engine.Register("initapi", jobInitApi)
}

// jobInitApi runs the remote api server `srv` as a daemon,
// Only one api server can run at the same time - this is enforced by a pidfile.
// The signals SIGINT, SIGQUIT and SIGTERM are intercepted for cleanup.
func jobInitApi(job *engine.Job) engine.Status {
	job.Logf("Creating server")
	// FIXME: ImportEnv deprecates ConfigFromJob
	srv, err := NewServer(job.Eng, ConfigFromJob(job))
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if srv.runtime.config.Pidfile != "" {
		job.Logf("Creating pidfile")
		if err := utils.CreatePidFile(srv.runtime.config.Pidfile); err != nil {
			// FIXME: do we need fatal here instead of returning a job error?
			log.Fatal(err)
		}
	}
	job.Logf("Setting up signal traps")
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt, syscall.SIGTERM, syscall.SIGQUIT)
	go func() {
		sig := <-c
		log.Printf("Received signal '%v', exiting\n", sig)
		utils.RemovePidFile(srv.runtime.config.Pidfile)
		srv.Close()
		os.Exit(0)
	}()
	job.Eng.Hack_SetGlobalVar("httpapi.server", srv)
	job.Eng.Hack_SetGlobalVar("httpapi.runtime", srv.runtime)
	// https://github.com/dotcloud/docker/issues/2768
	if srv.runtime.networkManager.bridgeNetwork != nil {
		job.Eng.Hack_SetGlobalVar("httpapi.bridgeIP", srv.runtime.networkManager.bridgeNetwork.IP)
	}
	if err := job.Eng.Register("export", srv.ContainerExport); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("create", srv.ContainerCreate); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("stop", srv.ContainerStop); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("restart", srv.ContainerRestart); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("start", srv.ContainerStart); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("kill", srv.ContainerKill); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("serveapi", srv.ListenAndServe); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("wait", srv.ContainerWait); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("tag", srv.ImageTag); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("resize", srv.ContainerResize); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("commit", srv.ContainerCommit); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("info", srv.DockerInfo); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("container_delete", srv.ContainerDestroy); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("image_export", srv.ImageExport); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("images", srv.Images); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("history", srv.ImageHistory); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("viz", srv.ImagesViz); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("container_copy", srv.ContainerCopy); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("insert", srv.ImageInsert); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("attach", srv.ContainerAttach); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("search", srv.ImagesSearch); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if err := job.Eng.Register("changes", srv.ContainerChanges); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ListenAndServe(job *engine.Job) engine.Status {
	protoAddrs := job.Args
	chErrors := make(chan error, len(protoAddrs))
	for _, protoAddr := range protoAddrs {
		protoAddrParts := strings.SplitN(protoAddr, "://", 2)
		switch protoAddrParts[0] {
		case "unix":
			if err := syscall.Unlink(protoAddrParts[1]); err != nil && !os.IsNotExist(err) {
				log.Fatal(err)
			}
		case "tcp":
			if !strings.HasPrefix(protoAddrParts[1], "127.0.0.1") {
				log.Println("/!\\ DON'T BIND ON ANOTHER IP ADDRESS THAN 127.0.0.1 IF YOU DON'T KNOW WHAT YOU'RE DOING /!\\")
			}
		default:
			job.Errorf("Invalid protocol format.")
			return engine.StatusErr
		}
		go func() {
			// FIXME: merge Server.ListenAndServe with ListenAndServe
			chErrors <- ListenAndServe(protoAddrParts[0], protoAddrParts[1], srv, job.GetenvBool("Logging"))
		}()
	}
	for i := 0; i < len(protoAddrs); i += 1 {
		err := <-chErrors
		if err != nil {
			job.Error(err)
			return engine.StatusErr
		}
	}
	return engine.StatusOK
}

// simpleVersionInfo is a simple implementation of
// the interface VersionInfo, which is used
// to provide version information for some product,
// component, etc. It stores the product name and the version
// in string and returns them on calls to Name() and Version().
type simpleVersionInfo struct {
	name    string
	version string
}

func (v *simpleVersionInfo) Name() string {
	return v.name
}

func (v *simpleVersionInfo) Version() string {
	return v.version
}

// ContainerKill send signal to the container
// If no signal is given (sig 0), then Kill with SIGKILL and wait
// for the container to exit.
// If a signal is given, then just send it to the container and return.
func (srv *Server) ContainerKill(job *engine.Job) engine.Status {
	if n := len(job.Args); n < 1 || n > 2 {
		job.Errorf("Usage: %s CONTAINER [SIGNAL]", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	var sig uint64
	if len(job.Args) == 2 && job.Args[1] != "" {
		var err error
		// The largest legal signal is 31, so let's parse on 5 bits
		sig, err = strconv.ParseUint(job.Args[1], 10, 5)
		if err != nil {
			job.Errorf("Invalid signal: %s", job.Args[1])
			return engine.StatusErr
		}
	}
	if container := srv.runtime.Get(name); container != nil {
		// If no signal is passed, perform regular Kill (SIGKILL + wait())
		if sig == 0 {
			if err := container.Kill(); err != nil {
				job.Errorf("Cannot kill container %s: %s", name, err)
				return engine.StatusErr
			}
			srv.LogEvent("kill", container.ID, srv.runtime.repositories.ImageName(container.Image))
		} else {
			// Otherwise, just send the requested signal
			if err := container.kill(int(sig)); err != nil {
				job.Errorf("Cannot kill container %s: %s", name, err)
				return engine.StatusErr
			}
			// FIXME: Add event for signals
		}
	} else {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ContainerExport(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s container_id", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	if container := srv.runtime.Get(name); container != nil {
		data, err := container.Export()
		if err != nil {
			job.Errorf("%s: %s", name, err)
			return engine.StatusErr
		}

		// Stream the entire contents of the container (basically a volatile snapshot)
		if _, err := io.Copy(job.Stdout, data); err != nil {
			job.Errorf("%s: %s", name, err)
			return engine.StatusErr
		}
		// FIXME: factor job-specific LogEvent to engine.Job.Run()
		srv.LogEvent("export", container.ID, srv.runtime.repositories.ImageName(container.Image))
		return engine.StatusOK
	}
	job.Errorf("No such container: %s", name)
	return engine.StatusErr
}

// ImageExport exports all images with the given tag. All versions
// containing the same tag are exported. The resulting output is an
// uncompressed tar ball.
// name is the set of tags to export.
// out is the writer where the images are written to.
func (srv *Server) ImageExport(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	// get image json
	tempdir, err := ioutil.TempDir("", "docker-export-")
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	defer os.RemoveAll(tempdir)

	utils.Debugf("Serializing %s", name)

	rootRepo, err := srv.runtime.repositories.Get(name)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if rootRepo != nil {
		for _, id := range rootRepo {
			image, err := srv.ImageInspect(id)
			if err != nil {
				job.Error(err)
				return engine.StatusErr
			}

			if err := srv.exportImage(image, tempdir); err != nil {
				job.Error(err)
				return engine.StatusErr
			}
		}

		// write repositories
		rootRepoMap := map[string]Repository{}
		rootRepoMap[name] = rootRepo
		rootRepoJson, _ := json.Marshal(rootRepoMap)

		if err := ioutil.WriteFile(path.Join(tempdir, "repositories"), rootRepoJson, os.ModeAppend); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
	} else {
		image, err := srv.ImageInspect(name)
		if err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		if err := srv.exportImage(image, tempdir); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
	}

	fs, err := archive.Tar(tempdir, archive.Uncompressed)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	if _, err := io.Copy(job.Stdout, fs); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) exportImage(image *Image, tempdir string) error {
	for i := image; i != nil; {
		// temporary directory
		tmpImageDir := path.Join(tempdir, i.ID)
		if err := os.Mkdir(tmpImageDir, os.ModeDir); err != nil {
			if os.IsExist(err) {
				return nil
			}
			return err
		}

		var version = "1.0"
		var versionBuf = []byte(version)

		if err := ioutil.WriteFile(path.Join(tmpImageDir, "VERSION"), versionBuf, os.ModeAppend); err != nil {
			return err
		}

		// serialize json
		b, err := json.Marshal(i)
		if err != nil {
			return err
		}
		if err := ioutil.WriteFile(path.Join(tmpImageDir, "json"), b, os.ModeAppend); err != nil {
			return err
		}

		// serialize filesystem
		fs, err := i.TarLayer()
		if err != nil {
			return err
		}

		fsTar, err := os.Create(path.Join(tmpImageDir, "layer.tar"))
		if err != nil {
			return err
		}
		if _, err = io.Copy(fsTar, fs); err != nil {
			return err
		}
		fsTar.Close()

		// find parent
		if i.Parent != "" {
			i, err = srv.ImageInspect(i.Parent)
			if err != nil {
				return err
			}
		} else {
			i = nil
		}
	}
	return nil
}

// Loads a set of images into the repository. This is the complementary of ImageExport.
// The input stream is an uncompressed tar ball containing images and metadata.
func (srv *Server) ImageLoad(in io.Reader) error {
	tmpImageDir, err := ioutil.TempDir("", "docker-import-")
	if err != nil {
		return err
	}
	defer os.RemoveAll(tmpImageDir)

	var (
		repoTarFile = path.Join(tmpImageDir, "repo.tar")
		repoDir     = path.Join(tmpImageDir, "repo")
	)

	tarFile, err := os.Create(repoTarFile)
	if err != nil {
		return err
	}
	if _, err := io.Copy(tarFile, in); err != nil {
		return err
	}
	tarFile.Close()

	repoFile, err := os.Open(repoTarFile)
	if err != nil {
		return err
	}
	if err := os.Mkdir(repoDir, os.ModeDir); err != nil {
		return err
	}
	if err := archive.Untar(repoFile, repoDir, nil); err != nil {
		return err
	}

	dirs, err := ioutil.ReadDir(repoDir)
	if err != nil {
		return err
	}

	for _, d := range dirs {
		if d.IsDir() {
			if err := srv.recursiveLoad(d.Name(), tmpImageDir); err != nil {
				return err
			}
		}
	}

	repositoriesJson, err := ioutil.ReadFile(path.Join(tmpImageDir, "repo", "repositories"))
	if err == nil {
		repositories := map[string]Repository{}
		if err := json.Unmarshal(repositoriesJson, &repositories); err != nil {
			return err
		}

		for imageName, tagMap := range repositories {
			for tag, address := range tagMap {
				if err := srv.runtime.repositories.Set(imageName, tag, address, true); err != nil {
					return err
				}
			}
		}
	} else if !os.IsNotExist(err) {
		return err
	}

	return nil
}

func (srv *Server) recursiveLoad(address, tmpImageDir string) error {
	if _, err := srv.ImageInspect(address); err != nil {
		utils.Debugf("Loading %s", address)

		imageJson, err := ioutil.ReadFile(path.Join(tmpImageDir, "repo", address, "json"))
		if err != nil {
			utils.Debugf("Error reading json", err)
			return err
		}

		layer, err := os.Open(path.Join(tmpImageDir, "repo", address, "layer.tar"))
		if err != nil {
			utils.Debugf("Error reading embedded tar", err)
			return err
		}
		img, err := NewImgJSON(imageJson)
		if err != nil {
			utils.Debugf("Error unmarshalling json", err)
			return err
		}
		if img.Parent != "" {
			if !srv.runtime.graph.Exists(img.Parent) {
				if err := srv.recursiveLoad(img.Parent, tmpImageDir); err != nil {
					return err
				}
			}
		}
		if err := srv.runtime.graph.Register(imageJson, layer, img); err != nil {
			return err
		}
	}
	utils.Debugf("Completed processing %s", address)

	return nil
}

func (srv *Server) ImagesSearch(job *engine.Job) engine.Status {
	if n := len(job.Args); n != 1 {
		job.Errorf("Usage: %s TERM", job.Name)
		return engine.StatusErr
	}
	term := job.Args[0]

	r, err := registry.NewRegistry(nil, srv.HTTPRequestFactory(nil), auth.IndexServerAddress())
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	results, err := r.SearchRepositories(term)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	outs := engine.NewTable("star_count", 0)
	for _, result := range results.Results {
		out := &engine.Env{}
		out.Import(result)
		outs.Add(out)
	}
	outs.ReverseSort()
	if _, err := outs.WriteTo(job.Stdout); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ImageInsert(job *engine.Job) engine.Status {
	if len(job.Args) != 3 {
		job.Errorf("Usage: %s IMAGE URL PATH\n", job.Name)
		return engine.StatusErr
	}

	var (
		name = job.Args[0]
		url  = job.Args[1]
		path = job.Args[2]
	)

	sf := utils.NewStreamFormatter(job.GetenvBool("json"))

	out := utils.NewWriteFlusher(job.Stdout)
	img, err := srv.runtime.repositories.LookupImage(name)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	file, err := utils.Download(url)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	defer file.Body.Close()

	config, _, _, err := ParseRun([]string{img.ID, "echo", "insert", url, path}, srv.runtime.capabilities)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	c, _, err := srv.runtime.Create(config, "")
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	if err := c.Inject(utils.ProgressReader(file.Body, int(file.ContentLength), out, sf, false, utils.TruncateID(img.ID), "Downloading"), path); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	// FIXME: Handle custom repo, tag comment, author
	img, err = srv.runtime.Commit(c, "", "", img.Comment, img.Author, nil)
	if err != nil {
		out.Write(sf.FormatError(err))
		return engine.StatusErr
	}
	out.Write(sf.FormatStatus("", img.ID))
	return engine.StatusOK
}

func (srv *Server) ImagesViz(job *engine.Job) engine.Status {
	images, _ := srv.runtime.graph.Map()
	if images == nil {
		return engine.StatusOK
	}
	job.Stdout.Write([]byte("digraph docker {\n"))

	var (
		parentImage *Image
		err         error
	)
	for _, image := range images {
		parentImage, err = image.GetParent()
		if err != nil {
			job.Errorf("Error while getting parent image: %v", err)
			return engine.StatusErr
		}
		if parentImage != nil {
			job.Stdout.Write([]byte(" \"" + parentImage.ID + "\" -> \"" + image.ID + "\"\n"))
		} else {
			job.Stdout.Write([]byte(" base -> \"" + image.ID + "\" [style=invis]\n"))
		}
	}

	reporefs := make(map[string][]string)

	for name, repository := range srv.runtime.repositories.Repositories {
		for tag, id := range repository {
			reporefs[utils.TruncateID(id)] = append(reporefs[utils.TruncateID(id)], fmt.Sprintf("%s:%s", name, tag))
		}
	}

	for id, repos := range reporefs {
		job.Stdout.Write([]byte(" \"" + id + "\" [label=\"" + id + "\\n" + strings.Join(repos, "\\n") + "\",shape=box,fillcolor=\"paleturquoise\",style=\"filled,rounded\"];\n"))
	}
	job.Stdout.Write([]byte(" base [style=invisible]\n}\n"))
	return engine.StatusOK
}

func (srv *Server) Images(job *engine.Job) engine.Status {
	var (
		allImages map[string]*Image
		err       error
	)
	if job.GetenvBool("all") {
		allImages, err = srv.runtime.graph.Map()
	} else {
		allImages, err = srv.runtime.graph.Heads()
	}
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	lookup := make(map[string]*engine.Env)
	for name, repository := range srv.runtime.repositories.Repositories {
		if job.Getenv("filter") != "" {
			if match, _ := path.Match(job.Getenv("filter"), name); !match {
				continue
			}
		}
		for tag, id := range repository {
			image, err := srv.runtime.graph.Get(id)
			if err != nil {
				log.Printf("Warning: couldn't load %s from %s/%s: %s", id, name, tag, err)
				continue
			}

			if out, exists := lookup[id]; exists {
				out.SetList("RepoTags", append(out.GetList("RepoTags"), fmt.Sprintf("%s:%s", name, tag)))
			} else {
				out := &engine.Env{}
				delete(allImages, id)
				out.Set("ParentId", image.Parent)
				out.SetList("RepoTags", []string{fmt.Sprintf("%s:%s", name, tag)})
				out.Set("ID", image.ID)
				out.SetInt64("Created", image.Created.Unix())
				out.SetInt64("Size", image.Size)
				out.SetInt64("VirtualSize", image.getParentsSize(0)+image.Size)
				lookup[id] = out
			}

		}
	}

	outs := engine.NewTable("Created", len(lookup))
	for _, value := range lookup {
		outs.Add(value)
	}

	// Display images which aren't part of a repository/tag
	if job.Getenv("filter") == "" {
		for _, image := range allImages {
			out := &engine.Env{}
			out.Set("ParentId", image.Parent)
			out.SetList("RepoTags", []string{"<none>:<none>"})
			out.Set("ID", image.ID)
			out.SetInt64("Created", image.Created.Unix())
			out.SetInt64("Size", image.Size)
			out.SetInt64("VirtualSize", image.getParentsSize(0)+image.Size)
			outs.Add(out)
		}
	}

	outs.ReverseSort()
	if _, err := outs.WriteTo(job.Stdout); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) DockerInfo(job *engine.Job) engine.Status {
	images, _ := srv.runtime.graph.Map()
	var imgcount int
	if images == nil {
		imgcount = 0
	} else {
		imgcount = len(images)
	}
	lxcVersion := ""
	if output, err := exec.Command("lxc-version").CombinedOutput(); err == nil {
		outputStr := string(output)
		if len(strings.SplitN(outputStr, ":", 2)) == 2 {
			lxcVersion = strings.TrimSpace(strings.SplitN(string(output), ":", 2)[1])
		}
	}
	kernelVersion := "<unknown>"
	if kv, err := utils.GetKernelVersion(); err == nil {
		kernelVersion = kv.String()
	}

	// if we still have the original dockerinit binary from before we copied it locally, let's return the path to that, since that's more intuitive (the copied path is trivial to derive by hand given VERSION)
	initPath := utils.DockerInitPath("")
	if initPath == "" {
		// if that fails, we'll just return the path from the runtime
		initPath = srv.runtime.sysInitPath
	}

	v := &engine.Env{}
	v.SetInt("Containers", len(srv.runtime.List()))
	v.SetInt("Images", imgcount)
	v.Set("Driver", srv.runtime.driver.String())
	v.SetJson("DriverStatus", srv.runtime.driver.Status())
	v.SetBool("MemoryLimit", srv.runtime.capabilities.MemoryLimit)
	v.SetBool("SwapLimit", srv.runtime.capabilities.SwapLimit)
	v.SetBool("IPv4Forwarding", !srv.runtime.capabilities.IPv4ForwardingDisabled)
	v.SetBool("Debug", os.Getenv("DEBUG") != "")
	v.SetInt("NFd", utils.GetTotalUsedFds())
	v.SetInt("NGoroutines", runtime.NumGoroutine())
	v.Set("LXCVersion", lxcVersion)
	v.SetInt("NEventsListener", len(srv.events))
	v.Set("KernelVersion", kernelVersion)
	v.Set("IndexServerAddress", auth.IndexServerAddress())
	v.Set("InitSha1", utils.INITSHA1)
	v.Set("InitPath", initPath)
	if _, err := v.WriteTo(job.Stdout); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ImageHistory(job *engine.Job) engine.Status {
	if n := len(job.Args); n != 1 {
		job.Errorf("Usage: %s IMAGE", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	image, err := srv.runtime.repositories.LookupImage(name)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	lookupMap := make(map[string][]string)
	for name, repository := range srv.runtime.repositories.Repositories {
		for tag, id := range repository {
			// If the ID already has a reverse lookup, do not update it unless for "latest"
			if _, exists := lookupMap[id]; !exists {
				lookupMap[id] = []string{}
			}
			lookupMap[id] = append(lookupMap[id], name+":"+tag)
		}
	}

	outs := engine.NewTable("Created", 0)
	err = image.WalkHistory(func(img *Image) error {
		out := &engine.Env{}
		out.Set("ID", img.ID)
		out.SetInt64("Created", img.Created.Unix())
		out.Set("CreatedBy", strings.Join(img.ContainerConfig.Cmd, " "))
		out.SetList("Tags", lookupMap[img.ID])
		out.SetInt64("Size", img.Size)
		outs.Add(out)
		return nil
	})
	outs.ReverseSort()
	if _, err := outs.WriteTo(job.Stdout); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ContainerTop(name, psArgs string) (*APITop, error) {
	if container := srv.runtime.Get(name); container != nil {
		if !container.State.IsRunning() {
			return nil, fmt.Errorf("Container %s is not running", name)
		}
		pids, err := cgroups.GetPidsForContainer(container.ID)
		if err != nil {
			return nil, err
		}
		if len(psArgs) == 0 {
			psArgs = "-ef"
		}
		output, err := exec.Command("ps", psArgs).Output()
		if err != nil {
			return nil, fmt.Errorf("Error running ps: %s", err)
		}

		lines := strings.Split(string(output), "\n")
		header := strings.Fields(lines[0])
		procs := APITop{
			Titles: header,
		}

		pidIndex := -1
		for i, name := range header {
			if name == "PID" {
				pidIndex = i
			}
		}
		if pidIndex == -1 {
			return nil, errors.New("Couldn't find PID field in ps output")
		}

		for _, line := range lines[1:] {
			if len(line) == 0 {
				continue
			}
			fields := strings.Fields(line)
			p, err := strconv.Atoi(fields[pidIndex])
			if err != nil {
				return nil, fmt.Errorf("Unexpected pid '%s': %s", fields[pidIndex], err)
			}

			for _, pid := range pids {
				if pid == p {
					// Make sure number of fields equals number of header titles
					// merging "overhanging" fields
					processes := fields[:len(procs.Titles)-1]
					processes = append(processes, strings.Join(fields[len(procs.Titles)-1:], " "))

					procs.Processes = append(procs.Processes, processes)
				}
			}
		}
		return &procs, nil

	}
	return nil, fmt.Errorf("No such container: %s", name)
}

func (srv *Server) ContainerChanges(job *engine.Job) engine.Status {
	if n := len(job.Args); n != 1 {
		job.Errorf("Usage: %s CONTAINER", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	if container := srv.runtime.Get(name); container != nil {
		outs := engine.NewTable("", 0)
		changes, err := container.Changes()
		if err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		for _, change := range changes {
			out := &engine.Env{}
			if err := out.Import(change); err != nil {
				job.Error(err)
				return engine.StatusErr
			}
			outs.Add(out)
		}
		if _, err := outs.WriteTo(job.Stdout); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
	} else {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) Containers(all, size bool, n int, since, before string) []APIContainers {
	var foundBefore bool
	var displayed int
	out := []APIContainers{}

	names := map[string][]string{}
	srv.runtime.containerGraph.Walk("/", func(p string, e *graphdb.Entity) error {
		names[e.ID()] = append(names[e.ID()], p)
		return nil
	}, -1)

	for _, container := range srv.runtime.List() {
		if !container.State.IsRunning() && !all && n == -1 && since == "" && before == "" {
			continue
		}
		if before != "" && !foundBefore {
			if container.ID == before || utils.TruncateID(container.ID) == before {
				foundBefore = true
			}
			continue
		}
		if displayed == n {
			break
		}
		if container.ID == since || utils.TruncateID(container.ID) == since {
			break
		}
		displayed++
		c := createAPIContainer(names[container.ID], container, size, srv.runtime)
		out = append(out, c)
	}
	return out
}

func createAPIContainer(names []string, container *Container, size bool, runtime *Runtime) APIContainers {
	c := APIContainers{
		ID: container.ID,
	}
	c.Names = names
	c.Image = runtime.repositories.ImageName(container.Image)
	c.Command = fmt.Sprintf("%s %s", container.Path, strings.Join(container.Args, " "))
	c.Created = container.Created.Unix()
	c.Status = container.State.String()
	c.Ports = container.NetworkSettings.PortMappingAPI()
	if size {
		c.SizeRw, c.SizeRootFs = container.GetSize()
	}
	return c
}
func (srv *Server) ContainerCommit(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Not enough arguments. Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]

	container := srv.runtime.Get(name)
	if container == nil {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}
	var config Config
	if err := job.GetenvJson("config", &config); err != nil {
		job.Error(err)
		return engine.StatusErr
	}

	img, err := srv.runtime.Commit(container, job.Getenv("repo"), job.Getenv("tag"), job.Getenv("comment"), job.Getenv("author"), &config)
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	job.Printf("%s\n", img.ID)
	return engine.StatusOK
}

func (srv *Server) ImageTag(job *engine.Job) engine.Status {
	if len(job.Args) != 2 && len(job.Args) != 3 {
		job.Errorf("Usage: %s IMAGE REPOSITORY [TAG]\n", job.Name)
		return engine.StatusErr
	}
	var tag string
	if len(job.Args) == 3 {
		tag = job.Args[2]
	}
	if err := srv.runtime.repositories.Set(job.Args[1], tag, job.Args[0], job.GetenvBool("force")); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) pullImage(r *registry.Registry, out io.Writer, imgID, endpoint string, token []string, sf *utils.StreamFormatter) error {
	history, err := r.GetRemoteHistory(imgID, endpoint, token)
	if err != nil {
		return err
	}
	out.Write(sf.FormatProgress(utils.TruncateID(imgID), "Pulling dependent layers", nil))
	// FIXME: Try to stream the images?
	// FIXME: Launch the getRemoteImage() in goroutines

	for i := len(history) - 1; i >= 0; i-- {
		id := history[i]

		// ensure no two downloads of the same layer happen at the same time
		if c, err := srv.poolAdd("pull", "layer:"+id); err != nil {
			utils.Errorf("Image (id: %s) pull is already running, skipping: %v", id, err)
			<-c
		}
		defer srv.poolRemove("pull", "layer:"+id)

		if !srv.runtime.graph.Exists(id) {
			out.Write(sf.FormatProgress(utils.TruncateID(id), "Pulling metadata", nil))
			imgJSON, imgSize, err := r.GetRemoteImageJSON(id, endpoint, token)
			if err != nil {
				out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
				// FIXME: Keep going in case of error?
				return err
			}
			img, err := NewImgJSON(imgJSON)
			if err != nil {
				out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
				return fmt.Errorf("Failed to parse json: %s", err)
			}

			// Get the layer
			out.Write(sf.FormatProgress(utils.TruncateID(id), "Pulling fs layer", nil))
			layer, err := r.GetRemoteImageLayer(img.ID, endpoint, token)
			if err != nil {
				out.Write(sf.FormatProgress(utils.TruncateID(id), "Error pulling dependent layers", nil))
				return err
			}
			defer layer.Close()
			if err := srv.runtime.graph.Register(imgJSON, utils.ProgressReader(layer, imgSize, out, sf, false, utils.TruncateID(id), "Downloading"), img); err != nil {
				out.Write(sf.FormatProgress(utils.TruncateID(id), "Error downloading dependent layers", nil))
				return err
			}
		}
		out.Write(sf.FormatProgress(utils.TruncateID(id), "Download complete", nil))

	}
	return nil
}

func (srv *Server) pullRepository(r *registry.Registry, out io.Writer, localName, remoteName, askedTag string, sf *utils.StreamFormatter, parallel bool) error {
	out.Write(sf.FormatStatus("", "Pulling repository %s", localName))

	repoData, err := r.GetRepositoryData(remoteName)
	if err != nil {
		return err
	}

	utils.Debugf("Retrieving the tag list")
	tagsList, err := r.GetRemoteTags(repoData.Endpoints, remoteName, repoData.Tokens)
	if err != nil {
		utils.Errorf("%v", err)
		return err
	}

	for tag, id := range tagsList {
		repoData.ImgList[id] = &registry.ImgData{
			ID:       id,
			Tag:      tag,
			Checksum: "",
		}
	}

	utils.Debugf("Registering tags")
	// If no tag has been specified, pull them all
	if askedTag == "" {
		for tag, id := range tagsList {
			repoData.ImgList[id].Tag = tag
		}
	} else {
		// Otherwise, check that the tag exists and use only that one
		id, exists := tagsList[askedTag]
		if !exists {
			return fmt.Errorf("Tag %s not found in repository %s", askedTag, localName)
		}
		repoData.ImgList[id].Tag = askedTag
	}

	errors := make(chan error)
	for _, image := range repoData.ImgList {
		downloadImage := func(img *registry.ImgData) {
			if askedTag != "" && img.Tag != askedTag {
				utils.Debugf("(%s) does not match %s (id: %s), skipping", img.Tag, askedTag, img.ID)
				if parallel {
					errors <- nil
				}
				return
			}

			if img.Tag == "" {
				utils.Debugf("Image (id: %s) present in this repository but untagged, skipping", img.ID)
				if parallel {
					errors <- nil
				}
				return
			}

			// ensure no two downloads of the same image happen at the same time
			if c, err := srv.poolAdd("pull", "img:"+img.ID); err != nil {
				if c != nil {
					out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))
					<-c
					out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))
				} else {
					utils.Errorf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)
				}
				if parallel {
					errors <- nil
				}
				return
			}
			defer srv.poolRemove("pull", "img:"+img.ID)

			out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s", img.Tag, localName), nil))
			success := false
			var lastErr error
			for _, ep := range repoData.Endpoints {
				out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Pulling image (%s) from %s, endpoint: %s", img.Tag, localName, ep), nil))
				if err := srv.pullImage(r, out, img.ID, ep, repoData.Tokens, sf); err != nil {
					// Its 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(utils.TruncateID(img.ID), fmt.Sprintf("Error pulling image (%s) from %s, endpoint: %s, %s", img.Tag, localName, ep, err), nil))
					continue
				}
				success = true
				break
			}
			if !success {
				out.Write(sf.FormatProgress(utils.TruncateID(img.ID), fmt.Sprintf("Error pulling image (%s) from %s, %s", img.Tag, localName, lastErr), nil))
				if parallel {
					errors <- fmt.Errorf("Could not find repository on any of the indexed registries.")
					return
				}
			}
			out.Write(sf.FormatProgress(utils.TruncateID(img.ID), "Download complete", nil))

			if parallel {
				errors <- nil
			}
		}

		if parallel {
			go downloadImage(image)
		} else {
			downloadImage(image)
		}
	}
	if parallel {
		var lastError error
		for i := 0; i < len(repoData.ImgList); i++ {
			if err := <-errors; err != nil {
				lastError = err
			}
		}
		if lastError != nil {
			return lastError
		}

	}
	for tag, id := range tagsList {
		if askedTag != "" && tag != askedTag {
			continue
		}
		if err := srv.runtime.repositories.Set(localName, tag, id, true); err != nil {
			return err
		}
	}
	if err := srv.runtime.repositories.Save(); err != nil {
		return err
	}

	return nil
}

func (srv *Server) poolAdd(kind, key string) (chan struct{}, error) {
	srv.Lock()
	defer srv.Unlock()

	if c, exists := srv.pullingPool[key]; exists {
		return c, fmt.Errorf("pull %s is already in progress", key)
	}
	if c, exists := srv.pushingPool[key]; exists {
		return c, fmt.Errorf("push %s is already in progress", key)
	}

	c := make(chan struct{})
	switch kind {
	case "pull":
		srv.pullingPool[key] = c
	case "push":
		srv.pushingPool[key] = c
	default:
		return nil, fmt.Errorf("Unknown pool type")
	}
	return c, nil
}

func (srv *Server) poolRemove(kind, key string) error {
	srv.Lock()
	defer srv.Unlock()
	switch kind {
	case "pull":
		if c, exists := srv.pullingPool[key]; exists {
			close(c)
			delete(srv.pullingPool, key)
		}
	case "push":
		if c, exists := srv.pushingPool[key]; exists {
			close(c)
			delete(srv.pushingPool, key)
		}
	default:
		return fmt.Errorf("Unknown pool type")
	}
	return nil
}

func (srv *Server) ImagePull(localName string, tag string, out io.Writer, sf *utils.StreamFormatter, authConfig *auth.AuthConfig, metaHeaders map[string][]string, parallel bool) error {
	out = utils.NewWriteFlusher(out)

	c, err := srv.poolAdd("pull", localName+":"+tag)
	if err != nil {
		if c != nil {
			// Another pull of the same repository is already taking place; just wait for it to finish
			out.Write(sf.FormatStatus("", "Repository %s already being pulled by another client. Waiting.", localName))
			<-c
			return nil
		}
		return err
	}
	defer srv.poolRemove("pull", localName+":"+tag)

	// Resolve the Repository name from fqn to endpoint + name
	endpoint, remoteName, err := registry.ResolveRepositoryName(localName)
	if err != nil {
		return err
	}

	r, err := registry.NewRegistry(authConfig, srv.HTTPRequestFactory(metaHeaders), endpoint)
	if err != nil {
		return err
	}

	if endpoint == auth.IndexServerAddress() {
		// If pull "index.docker.io/foo/bar", it's stored locally under "foo/bar"
		localName = remoteName
	}

	if err = srv.pullRepository(r, out, localName, remoteName, tag, sf, parallel); err != nil {
		return err
	}

	return nil
}

// Retrieve the all the images to be uploaded in the correct order
// Note: we can't use a map as it is not ordered
func (srv *Server) getImageList(localRepo map[string]string) ([][]*registry.ImgData, error) {
	imgList := map[string]*registry.ImgData{}
	depGraph := utils.NewDependencyGraph()

	for tag, id := range localRepo {
		img, err := srv.runtime.graph.Get(id)
		if err != nil {
			return nil, err
		}
		depGraph.NewNode(img.ID)
		img.WalkHistory(func(current *Image) error {
			imgList[current.ID] = &registry.ImgData{
				ID:  current.ID,
				Tag: tag,
			}
			parent, err := current.GetParent()
			if err != nil {
				return err
			}
			if parent == nil {
				return nil
			}
			depGraph.NewNode(parent.ID)
			depGraph.AddDependency(current.ID, parent.ID)
			return nil
		})
	}

	traversalMap, err := depGraph.GenerateTraversalMap()
	if err != nil {
		return nil, err
	}

	utils.Debugf("Traversal map: %v", traversalMap)
	result := [][]*registry.ImgData{}
	for _, round := range traversalMap {
		dataRound := []*registry.ImgData{}
		for _, imgID := range round {
			dataRound = append(dataRound, imgList[imgID])
		}
		result = append(result, dataRound)
	}
	return result, nil
}

func flatten(slc [][]*registry.ImgData) []*registry.ImgData {
	result := []*registry.ImgData{}
	for _, x := range slc {
		result = append(result, x...)
	}
	return result
}

func (srv *Server) pushRepository(r *registry.Registry, out io.Writer, localName, remoteName string, localRepo map[string]string, sf *utils.StreamFormatter) error {
	out = utils.NewWriteFlusher(out)
	imgList, err := srv.getImageList(localRepo)
	if err != nil {
		return err
	}
	flattenedImgList := flatten(imgList)
	out.Write(sf.FormatStatus("", "Sending image list"))

	var repoData *registry.RepositoryData
	repoData, err = r.PushImageJSONIndex(remoteName, flattenedImgList, false, nil)
	if err != nil {
		return err
	}

	for _, ep := range repoData.Endpoints {
		out.Write(sf.FormatStatus("", "Pushing repository %s (%d tags)", localName, len(localRepo)))
		// This section can not be parallelized (each round depends on the previous one)
		for i, round := range imgList {
			// FIXME: This section can be parallelized
			for _, elem := range round {
				var pushTags func() error
				pushTags = func() error {
					if i < (len(imgList) - 1) {
						// Only tag the top layer in the repository
						return nil
					}

					out.Write(sf.FormatStatus("", "Pushing tags for rev [%s] on {%s}", utils.TruncateID(elem.ID), ep+"repositories/"+remoteName+"/tags/"+elem.Tag))
					if err := r.PushRegistryTag(remoteName, elem.ID, elem.Tag, ep, repoData.Tokens); err != nil {
						return err
					}
					return nil
				}
				if _, exists := repoData.ImgList[elem.ID]; exists {
					if err := pushTags(); err != nil {
						return err
					}
					out.Write(sf.FormatProgress(utils.TruncateID(elem.ID), "Image already pushed, skipping", nil))
					continue
				} else if r.LookupRemoteImage(elem.ID, ep, repoData.Tokens) {
					if err := pushTags(); err != nil {
						return err
					}
					out.Write(sf.FormatProgress(utils.TruncateID(elem.ID), "Image already pushed, skipping", nil))
					continue
				}
				checksum, err := srv.pushImage(r, out, remoteName, elem.ID, ep, repoData.Tokens, sf)
				if err != nil {
					// FIXME: Continue on error?
					return err
				}
				elem.Checksum = checksum

				if err := pushTags(); err != nil {
					return err
				}
			}
		}
	}

	if _, err := r.PushImageJSONIndex(remoteName, flattenedImgList, true, repoData.Endpoints); err != nil {
		return err
	}

	return nil
}

func (srv *Server) pushImage(r *registry.Registry, out io.Writer, remote, imgID, ep string, token []string, sf *utils.StreamFormatter) (checksum string, err error) {
	out = utils.NewWriteFlusher(out)
	jsonRaw, err := ioutil.ReadFile(path.Join(srv.runtime.graph.Root, imgID, "json"))
	if err != nil {
		return "", fmt.Errorf("Cannot retrieve the path for {%s}: %s", imgID, err)
	}
	out.Write(sf.FormatProgress(utils.TruncateID(imgID), "Pushing", nil))

	imgData := &registry.ImgData{
		ID: imgID,
	}

	// Send the json
	if err := r.PushImageJSONRegistry(imgData, jsonRaw, ep, token); err != nil {
		if err == registry.ErrAlreadyExists {
			out.Write(sf.FormatProgress(utils.TruncateID(imgData.ID), "Image already pushed, skipping", nil))
			return "", nil
		}
		return "", err
	}

	layerData, err := srv.runtime.graph.TempLayerArchive(imgID, archive.Uncompressed, sf, out)
	if err != nil {
		return "", fmt.Errorf("Failed to generate layer archive: %s", err)
	}
	defer os.RemoveAll(layerData.Name())

	// Send the layer
	checksum, err = r.PushImageLayerRegistry(imgData.ID, utils.ProgressReader(layerData, int(layerData.Size), out, sf, false, utils.TruncateID(imgData.ID), "Pushing"), ep, token, jsonRaw)
	if err != nil {
		return "", err
	}
	imgData.Checksum = checksum
	// Send the checksum
	if err := r.PushImageChecksumRegistry(imgData, ep, token); err != nil {
		return "", err
	}

	out.Write(sf.FormatProgress(utils.TruncateID(imgData.ID), "Image successfully pushed", nil))
	return imgData.Checksum, nil
}

// FIXME: Allow to interrupt current push when new push of same image is done.
func (srv *Server) ImagePush(localName string, out io.Writer, sf *utils.StreamFormatter, authConfig *auth.AuthConfig, metaHeaders map[string][]string) error {
	if _, err := srv.poolAdd("push", localName); err != nil {
		return err
	}
	defer srv.poolRemove("push", localName)

	// Resolve the Repository name from fqn to endpoint + name
	endpoint, remoteName, err := registry.ResolveRepositoryName(localName)
	if err != nil {
		return err
	}

	out = utils.NewWriteFlusher(out)
	img, err := srv.runtime.graph.Get(localName)
	r, err2 := registry.NewRegistry(authConfig, srv.HTTPRequestFactory(metaHeaders), endpoint)
	if err2 != nil {
		return err2
	}

	if err != nil {
		reposLen := len(srv.runtime.repositories.Repositories[localName])
		out.Write(sf.FormatStatus("", "The push refers to a repository [%s] (len: %d)", localName, reposLen))
		// If it fails, try to get the repository
		if localRepo, exists := srv.runtime.repositories.Repositories[localName]; exists {
			if err := srv.pushRepository(r, out, localName, remoteName, localRepo, sf); err != nil {
				return err
			}
			return nil
		}
		return err
	}

	var token []string
	out.Write(sf.FormatStatus("", "The push refers to an image: [%s]", localName))
	if _, err := srv.pushImage(r, out, remoteName, img.ID, endpoint, token, sf); err != nil {
		return err
	}
	return nil
}

func (srv *Server) ImageImport(src, repo, tag string, in io.Reader, out io.Writer, sf *utils.StreamFormatter) error {
	var archive io.Reader
	var resp *http.Response

	if src == "-" {
		archive = in
	} else {
		u, err := url.Parse(src)
		if err != nil {
			return err
		}
		if u.Scheme == "" {
			u.Scheme = "http"
			u.Host = src
			u.Path = ""
		}
		out.Write(sf.FormatStatus("", "Downloading from %s", u))
		// Download with curl (pretty progress bar)
		// If curl is not available, fallback to http.Get()
		resp, err = utils.Download(u.String())
		if err != nil {
			return err
		}
		archive = utils.ProgressReader(resp.Body, int(resp.ContentLength), out, sf, true, "", "Importing")
	}
	img, err := srv.runtime.graph.Create(archive, nil, "Imported from "+src, "", nil)
	if err != nil {
		return err
	}
	// Optionally register the image at REPO/TAG
	if repo != "" {
		if err := srv.runtime.repositories.Set(repo, tag, img.ID, true); err != nil {
			return err
		}
	}
	out.Write(sf.FormatStatus("", img.ID))
	return nil
}

func (srv *Server) ContainerCreate(job *engine.Job) engine.Status {
	var name string
	if len(job.Args) == 1 {
		name = job.Args[0]
	} else if len(job.Args) > 1 {
		job.Printf("Usage: %s", job.Name)
		return engine.StatusErr
	}
	var config Config
	if err := job.ExportEnv(&config); err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if config.Memory != 0 && config.Memory < 524288 {
		job.Errorf("Minimum memory limit allowed is 512k")
		return engine.StatusErr
	}
	if config.Memory > 0 && !srv.runtime.capabilities.MemoryLimit {
		config.Memory = 0
	}
	if config.Memory > 0 && !srv.runtime.capabilities.SwapLimit {
		config.MemorySwap = -1
	}
	container, buildWarnings, err := srv.runtime.Create(&config, name)
	if err != nil {
		if srv.runtime.graph.IsNotExist(err) {
			_, tag := utils.ParseRepositoryTag(config.Image)
			if tag == "" {
				tag = DEFAULTTAG
			}
			job.Errorf("No such image: %s (tag: %s)", config.Image, tag)
			return engine.StatusErr
		}
		job.Error(err)
		return engine.StatusErr
	}
	srv.LogEvent("create", container.ID, srv.runtime.repositories.ImageName(container.Image))
	// FIXME: this is necessary because runtime.Create might return a nil container
	// with a non-nil error. This should not happen! Once it's fixed we
	// can remove this workaround.
	if container != nil {
		job.Printf("%s\n", container.ID)
	}
	for _, warning := range buildWarnings {
		job.Errorf("%s\n", warning)
	}
	return engine.StatusOK
}

func (srv *Server) ContainerRestart(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	t := job.GetenvInt("t")
	if t == -1 {
		t = 10
	}
	if container := srv.runtime.Get(name); container != nil {
		if err := container.Restart(int(t)); err != nil {
			job.Errorf("Cannot restart container %s: %s\n", name, err)
			return engine.StatusErr
		}
		srv.LogEvent("restart", container.ID, srv.runtime.repositories.ImageName(container.Image))
	} else {
		job.Errorf("No such container: %s\n", name)
		return engine.StatusErr
	}
	return engine.StatusOK

}

func (srv *Server) ContainerDestroy(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Not enough arguments. Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	removeVolume := job.GetenvBool("removeVolume")
	removeLink := job.GetenvBool("removeLink")

	container := srv.runtime.Get(name)

	if removeLink {
		if container == nil {
			job.Errorf("No such link: %s", name)
			return engine.StatusErr
		}
		name, err := getFullName(name)
		if err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		parent, n := path.Split(name)
		if parent == "/" {
			job.Errorf("Conflict, cannot remove the default name of the container")
			return engine.StatusErr
		}
		pe := srv.runtime.containerGraph.Get(parent)
		if pe == nil {
			job.Errorf("Cannot get parent %s for name %s", parent, name)
			return engine.StatusErr
		}
		parentContainer := srv.runtime.Get(pe.ID())

		if parentContainer != nil && parentContainer.activeLinks != nil {
			if link, exists := parentContainer.activeLinks[n]; exists {
				link.Disable()
			} else {
				utils.Debugf("Could not find active link for %s", name)
			}
		}

		if err := srv.runtime.containerGraph.Delete(name); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		return engine.StatusOK
	}

	if container != nil {
		if container.State.IsRunning() {
			job.Errorf("Impossible to remove a running container, please stop it first")
			return engine.StatusErr
		}
		volumes := make(map[string]struct{})

		binds := make(map[string]struct{})

		for _, bind := range container.hostConfig.Binds {
			splitBind := strings.Split(bind, ":")
			source := splitBind[0]
			binds[source] = struct{}{}
		}

		// Store all the deleted containers volumes
		for _, volumeId := range container.Volumes {

			// Skip the volumes mounted from external
			if _, exists := binds[volumeId]; exists {
				continue
			}

			volumeId = strings.TrimSuffix(volumeId, "/layer")
			volumeId = filepath.Base(volumeId)
			volumes[volumeId] = struct{}{}
		}
		if err := srv.runtime.Destroy(container); err != nil {
			job.Errorf("Cannot destroy container %s: %s", name, err)
			return engine.StatusErr
		}
		srv.LogEvent("destroy", container.ID, srv.runtime.repositories.ImageName(container.Image))

		if removeVolume {
			// Retrieve all volumes from all remaining containers
			usedVolumes := make(map[string]*Container)
			for _, container := range srv.runtime.List() {
				for _, containerVolumeId := range container.Volumes {
					usedVolumes[containerVolumeId] = container
				}
			}

			for volumeId := range volumes {
				// If the requested volu
				if c, exists := usedVolumes[volumeId]; exists {
					log.Printf("The volume %s is used by the container %s. Impossible to remove it. Skipping.\n", volumeId, c.ID)
					continue
				}
				if err := srv.runtime.volumes.Delete(volumeId); err != nil {
					job.Error(err)
					return engine.StatusErr
				}
			}
		}
	} else {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}
	return engine.StatusOK
}

var ErrImageReferenced = errors.New("Image referenced by a repository")

func (srv *Server) deleteImageAndChildren(id string, imgs *[]APIRmi, byParents map[string][]*Image) error {
	// If the image is referenced by a repo, do not delete
	if len(srv.runtime.repositories.ByID()[id]) != 0 {
		return ErrImageReferenced
	}
	// If the image is not referenced but has children, go recursive
	referenced := false
	for _, img := range byParents[id] {
		if err := srv.deleteImageAndChildren(img.ID, imgs, byParents); err != nil {
			if err != ErrImageReferenced {
				return err
			}
			referenced = true
		}
	}
	if referenced {
		return ErrImageReferenced
	}

	// If the image is not referenced and has no children, remove it
	byParents, err := srv.runtime.graph.ByParent()
	if err != nil {
		return err
	}
	if len(byParents[id]) == 0 && srv.canDeleteImage(id) == nil {
		if err := srv.runtime.repositories.DeleteAll(id); err != nil {
			return err
		}
		err := srv.runtime.graph.Delete(id)
		if err != nil {
			return err
		}
		*imgs = append(*imgs, APIRmi{Deleted: id})
		srv.LogEvent("delete", id, "")
		return nil
	}
	return nil
}

func (srv *Server) deleteImageParents(img *Image, imgs *[]APIRmi) error {
	if img.Parent != "" {
		parent, err := srv.runtime.graph.Get(img.Parent)
		if err != nil {
			return err
		}
		byParents, err := srv.runtime.graph.ByParent()
		if err != nil {
			return err
		}
		// Remove all children images
		if err := srv.deleteImageAndChildren(img.Parent, imgs, byParents); err != nil {
			return err
		}
		return srv.deleteImageParents(parent, imgs)
	}
	return nil
}

func (srv *Server) deleteImage(img *Image, repoName, tag string) ([]APIRmi, error) {
	var (
		imgs = []APIRmi{}
		tags = []string{}
	)

	//If delete by id, see if the id belong only to one repository
	if repoName == "" {
		for _, repoAndTag := range srv.runtime.repositories.ByID()[img.ID] {
			parsedRepo, parsedTag := utils.ParseRepositoryTag(repoAndTag)
			if repoName == "" || repoName == parsedRepo {
				repoName = parsedRepo
				if parsedTag != "" {
					tags = append(tags, parsedTag)
				}
			} else if repoName != parsedRepo {
				// the id belongs to multiple repos, like base:latest and user:test,
				// in that case return conflict
				return nil, fmt.Errorf("Conflict, cannot delete image %s because it is tagged in multiple repositories", utils.TruncateID(img.ID))
			}
		}
	} else {
		tags = append(tags, tag)
	}

	//Untag the current image
	for _, tag := range tags {
		tagDeleted, err := srv.runtime.repositories.Delete(repoName, tag)
		if err != nil {
			return nil, err
		}
		if tagDeleted {
			imgs = append(imgs, APIRmi{Untagged: img.ID})
			srv.LogEvent("untag", img.ID, "")
		}
	}

	if len(srv.runtime.repositories.ByID()[img.ID]) == 0 {
		if err := srv.deleteImageAndChildren(img.ID, &imgs, nil); err != nil {
			if err != ErrImageReferenced {
				return imgs, err
			}
		} else if err := srv.deleteImageParents(img, &imgs); err != nil {
			if err != ErrImageReferenced {
				return imgs, err
			}
		}
	}
	return imgs, nil
}

func (srv *Server) ImageDelete(name string, autoPrune bool) ([]APIRmi, error) {
	var (
		repository, tag string
		img, err        = srv.runtime.repositories.LookupImage(name)
	)
	if err != nil {
		return nil, fmt.Errorf("No such image: %s", name)
	}

	// FIXME: What does autoPrune mean ?
	if !autoPrune {
		if err := srv.runtime.graph.Delete(img.ID); err != nil {
			return nil, fmt.Errorf("Cannot delete image %s: %s", name, err)
		}
		return nil, nil
	}

	if !strings.Contains(img.ID, name) {
		repository, tag = utils.ParseRepositoryTag(name)
	}

	// If we have a repo and the image is not referenced anywhere else
	// then just perform an untag and do not validate.
	//
	// i.e. only validate if we are performing an actual delete and not
	// an untag op
	if repository != "" && len(srv.runtime.repositories.ByID()[img.ID]) == 1 {
		// Prevent deletion if image is used by a container
		if err := srv.canDeleteImage(img.ID); err != nil {
			return nil, err
		}
	}
	return srv.deleteImage(img, repository, tag)
}

func (srv *Server) canDeleteImage(imgID string) error {
	for _, container := range srv.runtime.List() {
		parent, err := srv.runtime.repositories.LookupImage(container.Image)
		if err != nil {
			return err
		}

		if err := parent.WalkHistory(func(p *Image) error {
			if imgID == p.ID {
				return fmt.Errorf("Conflict, cannot delete %s because the container %s is using it", utils.TruncateID(imgID), utils.TruncateID(container.ID))
			}
			return nil
		}); err != nil {
			return err
		}
	}
	return nil
}

func (srv *Server) ImageGetCached(imgID string, config *Config) (*Image, error) {

	// Retrieve all images
	images, err := srv.runtime.graph.Map()
	if err != nil {
		return nil, err
	}

	// Store the tree in a map of map (map[parentId][childId])
	imageMap := make(map[string]map[string]struct{})
	for _, img := range images {
		if _, exists := imageMap[img.Parent]; !exists {
			imageMap[img.Parent] = make(map[string]struct{})
		}
		imageMap[img.Parent][img.ID] = struct{}{}
	}

	// Loop on the children of the given image and check the config
	var match *Image
	for elem := range imageMap[imgID] {
		img, err := srv.runtime.graph.Get(elem)
		if err != nil {
			return nil, err
		}
		if CompareConfig(&img.ContainerConfig, config) {
			if match == nil || match.Created.Before(img.Created) {
				match = img
			}
		}
	}
	return match, nil
}

func (srv *Server) RegisterLinks(container *Container, hostConfig *HostConfig) error {
	runtime := srv.runtime

	if hostConfig != nil && hostConfig.Links != nil {
		for _, l := range hostConfig.Links {
			parts, err := parseLink(l)
			if err != nil {
				return err
			}
			child, err := srv.runtime.GetByName(parts["name"])
			if err != nil {
				return err
			}
			if child == nil {
				return fmt.Errorf("Could not get container for %s", parts["name"])
			}
			if err := runtime.RegisterLink(container, child, parts["alias"]); err != nil {
				return err
			}
		}

		// After we load all the links into the runtime
		// set them to nil on the hostconfig
		hostConfig.Links = nil
		if err := container.writeHostConfig(); err != nil {
			return err
		}
	}
	return nil
}

func (srv *Server) ContainerStart(job *engine.Job) engine.Status {
	if len(job.Args) < 1 {
		job.Errorf("Usage: %s container_id", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	runtime := srv.runtime
	container := runtime.Get(name)

	if container == nil {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}
	// If no environment was set, then no hostconfig was passed.
	if len(job.Environ()) > 0 {
		var hostConfig HostConfig
		if err := job.ExportEnv(&hostConfig); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		// Validate the HostConfig binds. Make sure that:
		// 1) the source of a bind mount isn't /
		//         The bind mount "/:/foo" isn't allowed.
		// 2) Check that the source exists
		//        The source to be bind mounted must exist.
		for _, bind := range hostConfig.Binds {
			splitBind := strings.Split(bind, ":")
			source := splitBind[0]

			// refuse to bind mount "/" to the container
			if source == "/" {
				job.Errorf("Invalid bind mount '%s' : source can't be '/'", bind)
				return engine.StatusErr
			}

			// ensure the source exists on the host
			_, err := os.Stat(source)
			if err != nil && os.IsNotExist(err) {
				job.Errorf("Invalid bind mount '%s' : source doesn't exist", bind)
				return engine.StatusErr
			}
		}
		// Register any links from the host config before starting the container
		if err := srv.RegisterLinks(container, &hostConfig); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		container.hostConfig = &hostConfig
		container.ToDisk()
	}
	if err := container.Start(); err != nil {
		job.Errorf("Cannot start container %s: %s", name, err)
		return engine.StatusErr
	}
	srv.LogEvent("start", container.ID, runtime.repositories.ImageName(container.Image))

	return engine.StatusOK
}

func (srv *Server) ContainerStop(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	t := job.GetenvInt("t")
	if t == -1 {
		t = 10
	}
	if container := srv.runtime.Get(name); container != nil {
		if err := container.Stop(int(t)); err != nil {
			job.Errorf("Cannot stop container %s: %s\n", name, err)
			return engine.StatusErr
		}
		srv.LogEvent("stop", container.ID, srv.runtime.repositories.ImageName(container.Image))
	} else {
		job.Errorf("No such container: %s\n", name)
		return engine.StatusErr
	}
	return engine.StatusOK
}

func (srv *Server) ContainerWait(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	if container := srv.runtime.Get(name); container != nil {
		status := container.Wait()
		job.Printf("%d\n", status)
		return engine.StatusOK
	}
	job.Errorf("%s: no such container: %s", job.Name, name)
	return engine.StatusErr
}

func (srv *Server) ContainerResize(job *engine.Job) engine.Status {
	if len(job.Args) != 3 {
		job.Errorf("Not enough arguments. Usage: %s CONTAINER HEIGHT WIDTH\n", job.Name)
		return engine.StatusErr
	}
	name := job.Args[0]
	height, err := strconv.Atoi(job.Args[1])
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	width, err := strconv.Atoi(job.Args[2])
	if err != nil {
		job.Error(err)
		return engine.StatusErr
	}
	if container := srv.runtime.Get(name); container != nil {
		if err := container.Resize(height, width); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		return engine.StatusOK
	}
	job.Errorf("No such container: %s", name)
	return engine.StatusErr
}

func (srv *Server) ContainerAttach(job *engine.Job) engine.Status {
	if len(job.Args) != 1 {
		job.Errorf("Usage: %s CONTAINER\n", job.Name)
		return engine.StatusErr
	}

	var (
		name   = job.Args[0]
		logs   = job.GetenvBool("logs")
		stream = job.GetenvBool("stream")
		stdin  = job.GetenvBool("stdin")
		stdout = job.GetenvBool("stdout")
		stderr = job.GetenvBool("stderr")
	)

	container := srv.runtime.Get(name)
	if container == nil {
		job.Errorf("No such container: %s", name)
		return engine.StatusErr
	}

	//logs
	if logs {
		cLog, err := container.ReadLog("json")
		if err != nil && os.IsNotExist(err) {
			// Legacy logs
			utils.Debugf("Old logs format")
			if stdout {
				cLog, err := container.ReadLog("stdout")
				if err != nil {
					utils.Errorf("Error reading logs (stdout): %s", err)
				} else if _, err := io.Copy(job.Stdout, cLog); err != nil {
					utils.Errorf("Error streaming logs (stdout): %s", err)
				}
			}
			if stderr {
				cLog, err := container.ReadLog("stderr")
				if err != nil {
					utils.Errorf("Error reading logs (stderr): %s", err)
				} else if _, err := io.Copy(job.Stderr, cLog); err != nil {
					utils.Errorf("Error streaming logs (stderr): %s", err)
				}
			}
		} else if err != nil {
			utils.Errorf("Error reading logs (json): %s", err)
		} else {
			dec := json.NewDecoder(cLog)
			for {
				l := &utils.JSONLog{}

				if err := dec.Decode(l); err == io.EOF {
					break
				} else if err != nil {
					utils.Errorf("Error streaming logs: %s", err)
					break
				}
				if l.Stream == "stdout" && stdout {
					fmt.Fprintf(job.Stdout, "%s", l.Log)
				}
				if l.Stream == "stderr" && stderr {
					fmt.Fprintf(job.Stderr, "%s", l.Log)
				}
			}
		}
	}

	//stream
	if stream {
		if container.State.IsGhost() {
			job.Errorf("Impossible to attach to a ghost container")
			return engine.StatusErr
		}

		var (
			cStdin           io.ReadCloser
			cStdout, cStderr io.Writer
			cStdinCloser     io.Closer
		)

		if stdin {
			r, w := io.Pipe()
			go func() {
				defer w.Close()
				defer utils.Debugf("Closing buffered stdin pipe")
				io.Copy(w, job.Stdin)
			}()
			cStdin = r
			cStdinCloser = job.Stdin
		}
		if stdout {
			cStdout = job.Stdout
		}
		if stderr {
			cStderr = job.Stderr
		}

		<-container.Attach(cStdin, cStdinCloser, cStdout, cStderr)

		// If we are in stdinonce mode, wait for the process to end
		// otherwise, simply return
		if container.Config.StdinOnce && !container.Config.Tty {
			container.Wait()
		}
	}
	return engine.StatusOK
}

func (srv *Server) ContainerInspect(name string) (*Container, error) {
	if container := srv.runtime.Get(name); container != nil {
		return container, nil
	}
	return nil, fmt.Errorf("No such container: %s", name)
}

func (srv *Server) ImageInspect(name string) (*Image, error) {
	if image, err := srv.runtime.repositories.LookupImage(name); err == nil && image != nil {
		return image, nil
	}
	return nil, fmt.Errorf("No such image: %s", name)
}

func (srv *Server) ContainerCopy(job *engine.Job) engine.Status {
	if len(job.Args) != 2 {
		job.Errorf("Usage: %s CONTAINER RESOURCE\n", job.Name)
		return engine.StatusErr
	}

	var (
		name     = job.Args[0]
		resource = job.Args[1]
	)

	if container := srv.runtime.Get(name); container != nil {

		data, err := container.Copy(resource)
		if err != nil {
			job.Error(err)
			return engine.StatusErr
		}

		if _, err := io.Copy(job.Stdout, data); err != nil {
			job.Error(err)
			return engine.StatusErr
		}
		return engine.StatusOK
	}
	job.Errorf("No such container: %s", name)
	return engine.StatusErr

}

func NewServer(eng *engine.Engine, config *DaemonConfig) (*Server, error) {
	runtime, err := NewRuntime(config)
	if err != nil {
		return nil, err
	}
	srv := &Server{
		Eng:         eng,
		runtime:     runtime,
		pullingPool: make(map[string]chan struct{}),
		pushingPool: make(map[string]chan struct{}),
		events:      make([]utils.JSONMessage, 0, 64), //only keeps the 64 last events
		listeners:   make(map[string]chan utils.JSONMessage),
	}
	runtime.srv = srv
	return srv, nil
}

func (srv *Server) HTTPRequestFactory(metaHeaders map[string][]string) *utils.HTTPRequestFactory {
	srv.Lock()
	defer srv.Unlock()
	v := dockerVersion()
	httpVersion := make([]utils.VersionInfo, 0, 4)
	httpVersion = append(httpVersion, &simpleVersionInfo{"docker", v.Get("Version")})
	httpVersion = append(httpVersion, &simpleVersionInfo{"go", v.Get("GoVersion")})
	httpVersion = append(httpVersion, &simpleVersionInfo{"git-commit", v.Get("GitCommit")})
	httpVersion = append(httpVersion, &simpleVersionInfo{"kernel", v.Get("KernelVersion")})
	httpVersion = append(httpVersion, &simpleVersionInfo{"os", v.Get("Os")})
	httpVersion = append(httpVersion, &simpleVersionInfo{"arch", v.Get("Arch")})
	ud := utils.NewHTTPUserAgentDecorator(httpVersion...)
	md := &utils.HTTPMetaHeadersDecorator{
		Headers: metaHeaders,
	}
	factory := utils.NewHTTPRequestFactory(ud, md)
	return factory
}

func (srv *Server) LogEvent(action, id, from string) *utils.JSONMessage {
	now := time.Now().UTC().Unix()
	jm := utils.JSONMessage{Status: action, ID: id, From: from, Time: now}
	srv.AddEvent(jm)
	for _, c := range srv.listeners {
		select { // non blocking channel
		case c <- jm:
		default:
		}
	}
	return &jm
}

func (srv *Server) AddEvent(jm utils.JSONMessage) {
	srv.Lock()
	defer srv.Unlock()
	srv.events = append(srv.events, jm)
}

func (srv *Server) GetEvents() []utils.JSONMessage {
	srv.RLock()
	defer srv.RUnlock()
	return srv.events
}

type Server struct {
	sync.RWMutex
	runtime     *Runtime
	pullingPool map[string]chan struct{}
	pushingPool map[string]chan struct{}
	events      []utils.JSONMessage
	listeners   map[string]chan utils.JSONMessage
	Eng         *engine.Engine
}