new file mode 100644

@@ -0,0 +1,2 @@

+Tibor Vass <teabee89@gmail.com> (@tiborvass)

+Erik Hollensbe <github@hollensbe.org> (@erikh)

new file mode 100644

@@ -0,0 +1,911 @@

+package builder

+

+import (

+	"crypto/sha256"

+	"encoding/hex"

+	"encoding/json"

+	"errors"

+	"fmt"

+	"io"

+	"io/ioutil"

+	"net/url"

+	"os"

+	"path"

+	"path/filepath"

+	"reflect"

+	"regexp"

+	"sort"

+	"strings"

+	"syscall"

+	"time"

+

+	"github.com/docker/docker/archive"

+	"github.com/docker/docker/daemon"

+	"github.com/docker/docker/engine"

+	"github.com/docker/docker/nat"

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

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

+	"github.com/docker/docker/registry"

+	"github.com/docker/docker/runconfig"

+	"github.com/docker/docker/utils"

+)

+

+var (

+	ErrDockerfileEmpty = errors.New("Dockerfile cannot be empty")

+)

+

+type BuildFile interface {

+	Build(io.Reader) (string, error)

+	CmdFrom(string) error

+	CmdRun(string) error

+}

+

+type buildFile struct {

+	daemon *daemon.Daemon

+	eng    *engine.Engine

+

+	image      string

+	maintainer string

+	config     *runconfig.Config

+

+	contextPath string

+	context     *utils.TarSum

+

+	verbose      bool

+	utilizeCache bool

+	rm           bool

+	forceRm      bool

+

+	authConfig *registry.AuthConfig

+	configFile *registry.ConfigFile

+

+	tmpContainers map[string]struct{}

+	tmpImages     map[string]struct{}

+

+	outStream io.Writer

+	errStream io.Writer

+

+	// Deprecated, original writer used for ImagePull. To be removed.

+	outOld io.Writer

+	sf     *utils.StreamFormatter

+}

+

+func (b *buildFile) clearTmp(containers map[string]struct{}) {

+	for c := range containers {

+		tmp := b.daemon.Get(c)

+		if err := b.daemon.Destroy(tmp); err != nil {

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

+		} else {

+			delete(containers, c)

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

+		}

+	}

+}

+

+func (b *buildFile) CmdFrom(name string) error {

+	image, err := b.daemon.Repositories().LookupImage(name)

+	if err != nil {

+		if b.daemon.Graph().IsNotExist(err) {

+			remote, tag := utils.ParseRepositoryTag(name)

+			pullRegistryAuth := b.authConfig

+			if len(b.configFile.Configs) > 0 {

+				// The request came with a full auth config file, we prefer to use that

+				endpoint, _, err := registry.ResolveRepositoryName(remote)

+				if err != nil {

+					return err

+				}

+				resolvedAuth := b.configFile.ResolveAuthConfig(endpoint)

+				pullRegistryAuth = &resolvedAuth

+			}

+			job := b.eng.Job("pull", remote, tag)

+			job.SetenvBool("json", b.sf.Json())

+			job.SetenvBool("parallel", true)

+			job.SetenvJson("authConfig", pullRegistryAuth)

+			job.Stdout.Add(b.outOld)

+			if err := job.Run(); err != nil {

+				return err

+			}

+			image, err = b.daemon.Repositories().LookupImage(name)

+			if err != nil {

+				return err

+			}

+		} else {

+			return err

+		}

+	}

+	b.image = image.ID

+	b.config = &runconfig.Config{}

+	if image.Config != nil {

+		b.config = image.Config

+	}

+	if b.config.Env == nil || len(b.config.Env) == 0 {

+		b.config.Env = append(b.config.Env, "HOME=/", "PATH="+daemon.DefaultPathEnv)

+	}

+	// Process ONBUILD triggers if they exist

+	if nTriggers := len(b.config.OnBuild); nTriggers != 0 {

+		fmt.Fprintf(b.errStream, "# Executing %d build triggers\n", nTriggers)

+	}

+

+	// Copy the ONBUILD triggers, and remove them from the config, since the config will be commited.

+	onBuildTriggers := b.config.OnBuild

+	b.config.OnBuild = []string{}

+

+	for n, step := range onBuildTriggers {

+		splitStep := strings.Split(step, " ")

+		stepInstruction := strings.ToUpper(strings.Trim(splitStep[0], " "))

+		switch stepInstruction {

+		case "ONBUILD":

+			return fmt.Errorf("Source image contains forbidden chained `ONBUILD ONBUILD` trigger: %s", step)

+		case "MAINTAINER", "FROM":

+			return fmt.Errorf("Source image contains forbidden %s trigger: %s", stepInstruction, step)

+		}

+		if err := b.BuildStep(fmt.Sprintf("onbuild-%d", n), step); err != nil {

+			return err

+		}

+	}

+	return nil

+}

+

+// The ONBUILD command declares a build instruction to be executed in any future build

+// using the current image as a base.

+func (b *buildFile) CmdOnbuild(trigger string) error {

+	splitTrigger := strings.Split(trigger, " ")

+	triggerInstruction := strings.ToUpper(strings.Trim(splitTrigger[0], " "))

+	switch triggerInstruction {

+	case "ONBUILD":

+		return fmt.Errorf("Chaining ONBUILD via `ONBUILD ONBUILD` isn't allowed")

+	case "MAINTAINER", "FROM":

+		return fmt.Errorf("%s isn't allowed as an ONBUILD trigger", triggerInstruction)

+	}

+	b.config.OnBuild = append(b.config.OnBuild, trigger)

+	return b.commit("", b.config.Cmd, fmt.Sprintf("ONBUILD %s", trigger))

+}

+

+func (b *buildFile) CmdMaintainer(name string) error {

+	b.maintainer = name

+	return b.commit("", b.config.Cmd, fmt.Sprintf("MAINTAINER %s", name))

+}

+

+// probeCache checks to see if image-caching is enabled (`b.utilizeCache`)

+// and if so attempts to look up the current `b.image` and `b.config` pair

+// in the current server `b.daemon`. If an image is found, probeCache returns

+// `(true, nil)`. If no image is found, it returns `(false, nil)`. If there

+// is any error, it returns `(false, err)`.

+func (b *buildFile) probeCache() (bool, error) {

+	if b.utilizeCache {

+		if cache, err := b.daemon.ImageGetCached(b.image, b.config); err != nil {

+			return false, err

+		} else if cache != nil {

+			fmt.Fprintf(b.outStream, " ---> Using cache\n")

+			utils.Debugf("[BUILDER] Use cached version")

+			b.image = cache.ID

+			return true, nil

+		} else {

+			utils.Debugf("[BUILDER] Cache miss")

+		}

+	}

+	return false, nil

+}

+

+func (b *buildFile) CmdRun(args string) error {

+	if b.image == "" {

+		return fmt.Errorf("Please provide a source image with `from` prior to run")

+	}

+	config, _, _, err := runconfig.Parse(append([]string{b.image}, b.buildCmdFromJson(args)...), nil)

+	if err != nil {

+		return err

+	}

+

+	cmd := b.config.Cmd

+	b.config.Cmd = nil

+	runconfig.Merge(b.config, config)

+

+	defer func(cmd []string) { b.config.Cmd = cmd }(cmd)

+

+	utils.Debugf("Command to be executed: %v", b.config.Cmd)

+

+	hit, err := b.probeCache()

+	if err != nil {

+		return err

+	}

+	if hit {

+		return nil

+	}

+

+	c, err := b.create()

+	if err != nil {

+		return err

+	}

+	// Ensure that we keep the container mounted until the commit

+	// to avoid unmounting and then mounting directly again

+	c.Mount()

+	defer c.Unmount()

+

+	err = b.run(c)

+	if err != nil {

+		return err

+	}

+	if err := b.commit(c.ID, cmd, "run"); err != nil {

+		return err

+	}

+

+	return nil

+}

+

+func (b *buildFile) FindEnvKey(key string) int {

+	for k, envVar := range b.config.Env {

+		envParts := strings.SplitN(envVar, "=", 2)

+		if key == envParts[0] {

+			return k

+		}

+	}

+	return -1

+}

+

+func (b *buildFile) ReplaceEnvMatches(value string) (string, error) {

+	exp, err := regexp.Compile("(\\\\\\\\+|[^\\\\]|\\b|\\A)\\$({?)([[:alnum:]_]+)(}?)")

+	if err != nil {

+		return value, err

+	}

+	matches := exp.FindAllString(value, -1)

+	for _, match := range matches {

+		match = match[strings.Index(match, "$"):]

+		matchKey := strings.Trim(match, "${}")

+

+		for _, envVar := range b.config.Env {

+			envParts := strings.SplitN(envVar, "=", 2)

+			envKey := envParts[0]

+			envValue := envParts[1]

+

+			if envKey == matchKey {

+				value = strings.Replace(value, match, envValue, -1)

+				break

+			}

+		}

+	}

+	return value, nil

+}

+

+func (b *buildFile) CmdEnv(args string) error {

+	tmp := strings.SplitN(args, " ", 2)

+	if len(tmp) != 2 {

+		return fmt.Errorf("Invalid ENV format")

+	}

+	key := strings.Trim(tmp[0], " \t")

+	value := strings.Trim(tmp[1], " \t")

+

+	envKey := b.FindEnvKey(key)

+	replacedValue, err := b.ReplaceEnvMatches(value)

+	if err != nil {

+		return err

+	}

+	replacedVar := fmt.Sprintf("%s=%s", key, replacedValue)

+

+	if envKey >= 0 {

+		b.config.Env[envKey] = replacedVar

+	} else {

+		b.config.Env = append(b.config.Env, replacedVar)

+	}

+	return b.commit("", b.config.Cmd, fmt.Sprintf("ENV %s", replacedVar))

+}

+

+func (b *buildFile) buildCmdFromJson(args string) []string {

+	var cmd []string

+	if err := json.Unmarshal([]byte(args), &cmd); err != nil {

+		utils.Debugf("Error unmarshalling: %s, setting to /bin/sh -c", err)

+		cmd = []string{"/bin/sh", "-c", args}

+	}

+	return cmd

+}

+

+func (b *buildFile) CmdCmd(args string) error {

+	cmd := b.buildCmdFromJson(args)

+	b.config.Cmd = cmd

+	if err := b.commit("", b.config.Cmd, fmt.Sprintf("CMD %v", cmd)); err != nil {

+		return err

+	}

+	return nil

+}

+

+func (b *buildFile) CmdEntrypoint(args string) error {

+	entrypoint := b.buildCmdFromJson(args)

+	b.config.Entrypoint = entrypoint

+	if err := b.commit("", b.config.Cmd, fmt.Sprintf("ENTRYPOINT %v", entrypoint)); err != nil {

+		return err

+	}

+	return nil

+}

+

+func (b *buildFile) CmdExpose(args string) error {

+	portsTab := strings.Split(args, " ")

+

+	if b.config.ExposedPorts == nil {

+		b.config.ExposedPorts = make(nat.PortSet)

+	}

+	ports, _, err := nat.ParsePortSpecs(append(portsTab, b.config.PortSpecs...))

+	if err != nil {

+		return err

+	}

+	for port := range ports {

+		if _, exists := b.config.ExposedPorts[port]; !exists {

+			b.config.ExposedPorts[port] = struct{}{}

+		}

+	}

+	b.config.PortSpecs = nil

+

+	return b.commit("", b.config.Cmd, fmt.Sprintf("EXPOSE %v", ports))

+}

+

+func (b *buildFile) CmdUser(args string) error {

+	b.config.User = args

+	return b.commit("", b.config.Cmd, fmt.Sprintf("USER %v", args))

+}

+

+func (b *buildFile) CmdInsert(args string) error {

+	return fmt.Errorf("INSERT has been deprecated. Please use ADD instead")

+}

+

+func (b *buildFile) CmdCopy(args string) error {

+	return b.runContextCommand(args, false, false, "COPY")

+}

+

+func (b *buildFile) CmdWorkdir(workdir string) error {

+	if workdir[0] == '/' {

+		b.config.WorkingDir = workdir

+	} else {

+		if b.config.WorkingDir == "" {

+			b.config.WorkingDir = "/"

+		}

+		b.config.WorkingDir = filepath.Join(b.config.WorkingDir, workdir)

+	}

+	return b.commit("", b.config.Cmd, fmt.Sprintf("WORKDIR %v", workdir))

+}

+

+func (b *buildFile) CmdVolume(args string) error {

+	if args == "" {

+		return fmt.Errorf("Volume cannot be empty")

+	}

+

+	var volume []string

+	if err := json.Unmarshal([]byte(args), &volume); err != nil {

+		volume = []string{args}

+	}

+	if b.config.Volumes == nil {

+		b.config.Volumes = map[string]struct{}{}

+	}

+	for _, v := range volume {

+		b.config.Volumes[v] = struct{}{}

+	}

+	if err := b.commit("", b.config.Cmd, fmt.Sprintf("VOLUME %s", args)); err != nil {

+		return err

+	}

+	return nil

+}

+

+func (b *buildFile) checkPathForAddition(orig string) error {

+	origPath := path.Join(b.contextPath, orig)

+	if p, err := filepath.EvalSymlinks(origPath); err != nil {

+		if os.IsNotExist(err) {

+			return fmt.Errorf("%s: no such file or directory", orig)

+		}

+		return err

+	} else {

+		origPath = p

+	}

+	if !strings.HasPrefix(origPath, b.contextPath) {

+		return fmt.Errorf("Forbidden path outside the build context: %s (%s)", orig, origPath)

+	}

+	_, err := os.Stat(origPath)

+	if err != nil {

+		if os.IsNotExist(err) {

+			return fmt.Errorf("%s: no such file or directory", orig)

+		}

+		return err

+	}

+	return nil

+}

+

+func (b *buildFile) addContext(container *daemon.Container, orig, dest string, decompress bool) error {

+	var (

+		err        error

+		destExists = true

+		origPath   = path.Join(b.contextPath, orig)

+		destPath   = path.Join(container.RootfsPath(), dest)

+	)

+

+	if destPath != container.RootfsPath() {

+		destPath, err = symlink.FollowSymlinkInScope(destPath, container.RootfsPath())

+		if err != nil {

+			return err

+		}

+	}

+

+	// Preserve the trailing '/'

+	if strings.HasSuffix(dest, "/") || dest == "." {

+		destPath = destPath + "/"

+	}

+

+	destStat, err := os.Stat(destPath)

+	if err != nil {

+		if !os.IsNotExist(err) {

+			return err

+		}

+		destExists = false

+	}

+

+	fi, err := os.Stat(origPath)

+	if err != nil {

+		if os.IsNotExist(err) {

+			return fmt.Errorf("%s: no such file or directory", orig)

+		}

+		return err

+	}

+

+	if fi.IsDir() {

+		return copyAsDirectory(origPath, destPath, destExists)

+	}

+

+	// If we are adding a remote file (or we've been told not to decompress), do not try to untar it

+	if decompress {

+		// First try to unpack the source as an archive

+		// to support the untar feature we need to clean up the path a little bit

+		// because tar is very forgiving.  First we need to strip off the archive's

+		// filename from the path but this is only added if it does not end in / .

+		tarDest := destPath

+		if strings.HasSuffix(tarDest, "/") {

+			tarDest = filepath.Dir(destPath)

+		}

+

+		// try to successfully untar the orig

+		if err := archive.UntarPath(origPath, tarDest); err == nil {

+			return nil

+		} else if err != io.EOF {

+			utils.Debugf("Couldn't untar %s to %s: %s", origPath, tarDest, err)

+		}

+	}

+

+	if err := os.MkdirAll(path.Dir(destPath), 0755); err != nil {

+		return err

+	}

+	if err := archive.CopyWithTar(origPath, destPath); err != nil {

+		return err

+	}

+

+	resPath := destPath

+	if destExists && destStat.IsDir() {

+		resPath = path.Join(destPath, path.Base(origPath))

+	}

+

+	return fixPermissions(resPath, 0, 0)

+}

+

+func (b *buildFile) runContextCommand(args string, allowRemote bool, allowDecompression bool, cmdName string) error {

+	if b.context == nil {

+		return fmt.Errorf("No context given. Impossible to use %s", cmdName)

+	}

+	tmp := strings.SplitN(args, " ", 2)

+	if len(tmp) != 2 {

+		return fmt.Errorf("Invalid %s format", cmdName)

+	}

+

+	orig, err := b.ReplaceEnvMatches(strings.Trim(tmp[0], " \t"))

+	if err != nil {

+		return err

+	}

+

+	dest, err := b.ReplaceEnvMatches(strings.Trim(tmp[1], " \t"))

+	if err != nil {

+		return err

+	}

+

+	cmd := b.config.Cmd

+	b.config.Cmd = []string{"/bin/sh", "-c", fmt.Sprintf("#(nop) %s %s in %s", cmdName, orig, dest)}

+	defer func(cmd []string) { b.config.Cmd = cmd }(cmd)

+	b.config.Image = b.image

+

+	var (

+		origPath   = orig

+		destPath   = dest

+		remoteHash string

+		isRemote   bool

+		decompress = true

+	)

+

+	isRemote = utils.IsURL(orig)

+	if isRemote && !allowRemote {

+		return fmt.Errorf("Source can't be an URL for %s", cmdName)

+	} else if utils.IsURL(orig) {

+		// Initiate the download

+		resp, err := utils.Download(orig)

+		if err != nil {

+			return err

+		}

+

+		// Create a tmp dir

+		tmpDirName, err := ioutil.TempDir(b.contextPath, "docker-remote")

+		if err != nil {

+			return err

+		}

+

+		// Create a tmp file within our tmp dir

+		tmpFileName := path.Join(tmpDirName, "tmp")

+		tmpFile, err := os.OpenFile(tmpFileName, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)

+		if err != nil {

+			return err

+		}

+		defer os.RemoveAll(tmpDirName)

+

+		// Download and dump result to tmp file

+		if _, err := io.Copy(tmpFile, resp.Body); err != nil {

+			tmpFile.Close()

+			return err

+		}

+		tmpFile.Close()

+

+		// Remove the mtime of the newly created tmp file

+		if err := system.UtimesNano(tmpFileName, make([]syscall.Timespec, 2)); err != nil {

+			return err

+		}

+

+		origPath = path.Join(filepath.Base(tmpDirName), filepath.Base(tmpFileName))

+

+		// Process the checksum

+		r, err := archive.Tar(tmpFileName, archive.Uncompressed)

+		if err != nil {

+			return err

+		}

+		tarSum := &utils.TarSum{Reader: r, DisableCompression: true}

+		if _, err := io.Copy(ioutil.Discard, tarSum); err != nil {

+			return err

+		}

+		remoteHash = tarSum.Sum(nil)

+		r.Close()

+

+		// If the destination is a directory, figure out the filename.

+		if strings.HasSuffix(dest, "/") {

+			u, err := url.Parse(orig)

+			if err != nil {

+				return err

+			}

+			path := u.Path

+			if strings.HasSuffix(path, "/") {

+				path = path[:len(path)-1]

+			}

+			parts := strings.Split(path, "/")

+			filename := parts[len(parts)-1]

+			if filename == "" {

+				return fmt.Errorf("cannot determine filename from url: %s", u)

+			}

+			destPath = dest + filename

+		}

+	}

+

+	if err := b.checkPathForAddition(origPath); err != nil {

+		return err

+	}

+

+	// Hash path and check the cache

+	if b.utilizeCache {

+		var (

+			hash string

+			sums = b.context.GetSums()

+		)

+

+		if remoteHash != "" {

+			hash = remoteHash

+		} else if fi, err := os.Stat(path.Join(b.contextPath, origPath)); err != nil {

+			return err

+		} else if fi.IsDir() {

+			var subfiles []string

+			for file, sum := range sums {

+				absFile := path.Join(b.contextPath, file)

+				absOrigPath := path.Join(b.contextPath, origPath)

+				if strings.HasPrefix(absFile, absOrigPath) {

+					subfiles = append(subfiles, sum)

+				}

+			}

+			sort.Strings(subfiles)

+			hasher := sha256.New()

+			hasher.Write([]byte(strings.Join(subfiles, ",")))

+			hash = "dir:" + hex.EncodeToString(hasher.Sum(nil))

+		} else {

+			if origPath[0] == '/' && len(origPath) > 1 {

+				origPath = origPath[1:]

+			}

+			origPath = strings.TrimPrefix(origPath, "./")

+			if h, ok := sums[origPath]; ok {

+				hash = "file:" + h

+			}

+		}

+		b.config.Cmd = []string{"/bin/sh", "-c", fmt.Sprintf("#(nop) %s %s in %s", cmdName, hash, dest)}

+		hit, err := b.probeCache()

+		if err != nil {

+			return err

+		}

+		// If we do not have a hash, never use the cache

+		if hit && hash != "" {

+			return nil

+		}

+	}

+

+	// Create the container

+	container, _, err := b.daemon.Create(b.config, "")

+	if err != nil {

+		return err

+	}

+	b.tmpContainers[container.ID] = struct{}{}

+

+	if err := container.Mount(); err != nil {

+		return err

+	}

+	defer container.Unmount()

+

+	if !allowDecompression || isRemote {

+		decompress = false

+	}

+	if err := b.addContext(container, origPath, destPath, decompress); err != nil {

+		return err

+	}

+

+	if err := b.commit(container.ID, cmd, fmt.Sprintf("%s %s in %s", cmdName, orig, dest)); err != nil {

+		return err

+	}

+	return nil

+}

+

+func (b *buildFile) CmdAdd(args string) error {

+	return b.runContextCommand(args, true, true, "ADD")

+}

+

+func (b *buildFile) create() (*daemon.Container, error) {

+	if b.image == "" {

+		return nil, fmt.Errorf("Please provide a source image with `from` prior to run")

+	}

+	b.config.Image = b.image

+

+	// Create the container

+	c, _, err := b.daemon.Create(b.config, "")

+	if err != nil {

+		return nil, err

+	}

+	b.tmpContainers[c.ID] = struct{}{}

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

+

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

+	c.Path = b.config.Cmd[0]

+	c.Args = b.config.Cmd[1:]

+

+	return c, nil

+}

+

+func (b *buildFile) run(c *daemon.Container) error {

+	var errCh chan error

+	if b.verbose {

+		errCh = utils.Go(func() error {

+			return <-b.daemon.Attach(c, nil, nil, b.outStream, b.errStream)

+		})

+	}

+

+	//start the container

+	if err := c.Start(); err != nil {

+		return err

+	}

+

+	if errCh != nil {

+		if err := <-errCh; err != nil {

+			return err

+		}

+	}

+

+	// Wait for it to finish

+	if ret, _ := c.State.WaitStop(-1 * time.Second); ret != 0 {

+		err := &utils.JSONError{

+			Message: fmt.Sprintf("The command %v returned a non-zero code: %d", b.config.Cmd, ret),

+			Code:    ret,

+		}

+		return err

+	}

+

+	return nil

+}

+

+// Commit the container <id> with the autorun command <autoCmd>

+func (b *buildFile) commit(id string, autoCmd []string, comment string) error {

+	if b.image == "" {

+		return fmt.Errorf("Please provide a source image with `from` prior to commit")

+	}

+	b.config.Image = b.image

+	if id == "" {

+		cmd := b.config.Cmd

+		b.config.Cmd = []string{"/bin/sh", "-c", "#(nop) " + comment}

+		defer func(cmd []string) { b.config.Cmd = cmd }(cmd)

+

+		hit, err := b.probeCache()

+		if err != nil {

+			return err

+		}

+		if hit {

+			return nil

+		}

+

+		container, warnings, err := b.daemon.Create(b.config, "")

+		if err != nil {

+			return err

+		}

+		for _, warning := range warnings {

+			fmt.Fprintf(b.outStream, " ---> [Warning] %s\n", warning)

+		}

+		b.tmpContainers[container.ID] = struct{}{}

+		fmt.Fprintf(b.outStream, " ---> Running in %s\n", utils.TruncateID(container.ID))

+		id = container.ID

+

+		if err := container.Mount(); err != nil {

+			return err

+		}

+		defer container.Unmount()

+	}

+	container := b.daemon.Get(id)

+	if container == nil {

+		return fmt.Errorf("An error occured while creating the container")

+	}

+

+	// Note: Actually copy the struct

+	autoConfig := *b.config

+	autoConfig.Cmd = autoCmd

+	// Commit the container

+	image, err := b.daemon.Commit(container, "", "", "", b.maintainer, true, &autoConfig)

+	if err != nil {

+		return err

+	}

+	b.tmpImages[image.ID] = struct{}{}

+	b.image = image.ID

+	return nil

+}

+

+// Long lines can be split with a backslash

+var lineContinuation = regexp.MustCompile(`\\\s*\n`)

+

+func (b *buildFile) Build(context io.Reader) (string, error) {

+	tmpdirPath, err := ioutil.TempDir("", "docker-build")

+	if err != nil {

+		return "", err

+	}

+

+	decompressedStream, err := archive.DecompressStream(context)

+	if err != nil {

+		return "", err

+	}

+

+	b.context = &utils.TarSum{Reader: decompressedStream, DisableCompression: true}

+	if err := archive.Untar(b.context, tmpdirPath, nil); err != nil {

+		return "", err

+	}

+	defer os.RemoveAll(tmpdirPath)

+

+	b.contextPath = tmpdirPath

+	filename := path.Join(tmpdirPath, "Dockerfile")

+	if _, err := os.Stat(filename); os.IsNotExist(err) {

+		return "", fmt.Errorf("Can't build a directory with no Dockerfile")

+	}

+	fileBytes, err := ioutil.ReadFile(filename)

+	if err != nil {

+		return "", err

+	}

+	if len(fileBytes) == 0 {

+		return "", ErrDockerfileEmpty

+	}

+	var (

+		dockerfile = lineContinuation.ReplaceAllString(stripComments(fileBytes), "")

+		stepN      = 0

+	)

+	for _, line := range strings.Split(dockerfile, "\n") {

+		line = strings.Trim(strings.Replace(line, "\t", " ", -1), " \t\r\n")

+		if len(line) == 0 {

+			continue

+		}

+		if err := b.BuildStep(fmt.Sprintf("%d", stepN), line); err != nil {

+			if b.forceRm {

+				b.clearTmp(b.tmpContainers)

+			}

+			return "", err

+		} else if b.rm {

+			b.clearTmp(b.tmpContainers)

+		}

+		stepN += 1

+	}

+	if b.image != "" {

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

+		return b.image, nil

+	}

+	return "", fmt.Errorf("No image was generated. This may be because the Dockerfile does not, like, do anything.\n")

+}

+

+// BuildStep parses a single build step from `instruction` and executes it in the current context.

+func (b *buildFile) BuildStep(name, expression string) error {

+	fmt.Fprintf(b.outStream, "Step %s : %s\n", name, expression)

+	tmp := strings.SplitN(expression, " ", 2)

+	if len(tmp) != 2 {

+		return fmt.Errorf("Invalid Dockerfile format")

+	}

+	instruction := strings.ToLower(strings.Trim(tmp[0], " "))

+	arguments := strings.Trim(tmp[1], " ")

+

+	method, exists := reflect.TypeOf(b).MethodByName("Cmd" + strings.ToUpper(instruction[:1]) + strings.ToLower(instruction[1:]))

+	if !exists {

+		fmt.Fprintf(b.errStream, "# Skipping unknown instruction %s\n", strings.ToUpper(instruction))

+		return nil

+	}

+

+	ret := method.Func.Call([]reflect.Value{reflect.ValueOf(b), reflect.ValueOf(arguments)})[0].Interface()

+	if ret != nil {

+		return ret.(error)

+	}

+

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

+	return nil

+}

+

+func stripComments(raw []byte) string {

+	var (

+		out   []string

+		lines = strings.Split(string(raw), "\n")

+	)

+	for _, l := range lines {

+		if len(l) == 0 || l[0] == '#' {

+			continue

+		}

+		out = append(out, l)

+	}

+	return strings.Join(out, "\n")

+}

+

+func copyAsDirectory(source, destination string, destinationExists bool) error {

+	if err := archive.CopyWithTar(source, destination); err != nil {

+		return err

+	}

+

+	if destinationExists {

+		files, err := ioutil.ReadDir(source)

+		if err != nil {

+			return err

+		}

+

+		for _, file := range files {

+			if err := fixPermissions(filepath.Join(destination, file.Name()), 0, 0); err != nil {