Merge pull request #3016 from rhatdan/vendor

Vendor in latest containers/storage and containers/buildah

19 files changed, 440 insertions, 216 deletions

diff --git a/vendor.conf b/vendor.conf
index 572ae5fdb..02283beb9 100644
--- a/vendor.conf
+++ b/vendor.conf
@@ -19,7 +19,7 @@ github.com/containers/image v1.5.1
 github.com/vbauerster/mpb v3.3.4
 github.com/mattn/go-isatty v0.0.4
 github.com/VividCortex/ewma v1.1.1
-github.com/containers/storage v1.12.3
+github.com/containers/storage v1.12.5
 github.com/containers/psgo v1.2.1
 github.com/coreos/go-systemd v14
 github.com/coreos/pkg v4
@@ -94,7 +94,7 @@ k8s.io/apimachinery kubernetes-1.10.13-beta.0 https://github.com/kubernetes/apim
 k8s.io/client-go kubernetes-1.10.13-beta.0 https://github.com/kubernetes/client-go
 github.com/mrunalp/fileutils 7d4729fb36185a7c1719923406c9d40e54fb93c7
 github.com/varlink/go 3ac79db6fd6aec70924193b090962f92985fe199
-github.com/containers/buildah fcc12bdadf6a5fab77e62e1bd12663bb6fbc3eda
+github.com/containers/buildah v1.8.0
 # TODO: Gotty has not been updated since 2012. Can we find replacement?
 github.com/Nvveen/Gotty cd527374f1e5bff4938207604a14f2e38a9cf512
 github.com/fsouza/go-dockerclient v1.3.0
diff --git a/vendor/github.com/containers/buildah/add.go b/vendor/github.com/containers/buildah/add.go
index d42246d53..d67a481f1 100644
--- a/vendor/github.com/containers/buildah/add.go
+++ b/vendor/github.com/containers/buildah/add.go
@@ -292,7 +292,7 @@ func addHelper(excludes []DockerIgnore, extract bool, dest string, destfi os.Fil
 						break
 					}
 					// combine the filename with the dest directory
-					fpath := strings.TrimPrefix(path, options.ContextDir)
+					fpath := strings.TrimPrefix(path, esrc)
 					if err = copyFileWithTar(path, filepath.Join(dest, fpath)); err != nil {
 						return errors.Wrapf(err, "error copying %q to %q", path, dest)
 					}
diff --git a/vendor/github.com/containers/buildah/buildah.go b/vendor/github.com/containers/buildah/buildah.go
index 8b076630f..b6e6545ec 100644
--- a/vendor/github.com/containers/buildah/buildah.go
+++ b/vendor/github.com/containers/buildah/buildah.go
@@ -26,7 +26,7 @@ const (
 	Package = "buildah"
 	// Version for the Package.  Bump version in contrib/rpm/buildah.spec
 	// too.
-	Version = "1.8-dev"
+	Version = "1.8.0"
 	// The value we use to identify what type of information, currently a
 	// serialized Builder structure, we are using as per-container state.
 	// This should only be changed when we make incompatible changes to
@@ -282,6 +282,8 @@ type CommonBuildOptions struct {
 	CPUSetCPUs string
 	// CPUSetMems memory nodes (MEMs) in which to allow execution (0-3, 0,1). Only effective on NUMA systems.
 	CPUSetMems string
+	// HTTPProxy determines whether *_proxy env vars from the build host are passed into the container.
+	HTTPProxy bool
 	// Memory is the upper limit (in bytes) on how much memory running containers can use.
 	Memory int64
 	// DNSSearch is the list of DNS search domains to add to the build container's /etc/resolv.conf
diff --git a/vendor/github.com/containers/buildah/chroot/run.go b/vendor/github.com/containers/buildah/chroot/run.go
index ff39c2f24..1c3ac65f3 100644
--- a/vendor/github.com/containers/buildah/chroot/run.go
+++ b/vendor/github.com/containers/buildah/chroot/run.go
@@ -512,7 +512,7 @@ func runUsingChroot(spec *specs.Spec, bundlePath string, ctty *os.File, stdin io
 	logNamespaceDiagnostics(spec)
 
 	// If we have configured ID mappings, set them here so that they can apply to the child.
-	hostUidmap, hostGidmap, err := util.GetHostIDMappings("")
+	hostUidmap, hostGidmap, err := unshare.GetHostIDMappings("")
 	if err != nil {
 		return 1, err
 	}
diff --git a/vendor/github.com/containers/buildah/chroot/selinux.go b/vendor/github.com/containers/buildah/chroot/selinux.go
index 3e62d743d..08e8f998b 100644
--- a/vendor/github.com/containers/buildah/chroot/selinux.go
+++ b/vendor/github.com/containers/buildah/chroot/selinux.go
@@ -13,7 +13,7 @@ import (
 // setSelinuxLabel sets the process label for child processes that we'll start.
 func setSelinuxLabel(spec *specs.Spec) error {
 	logrus.Debugf("setting selinux label")
-	if spec.Process.SelinuxLabel != "" && selinux.EnforceMode() != selinux.Disabled {
+	if spec.Process.SelinuxLabel != "" && selinux.GetEnabled() {
 		if err := label.SetProcessLabel(spec.Process.SelinuxLabel); err != nil {
 			return errors.Wrapf(err, "error setting process label to %q", spec.Process.SelinuxLabel)
 		}
diff --git a/vendor/github.com/containers/buildah/commit.go b/vendor/github.com/containers/buildah/commit.go
index 5e73be881..05d1550b3 100644
--- a/vendor/github.com/containers/buildah/commit.go
+++ b/vendor/github.com/containers/buildah/commit.go
@@ -64,12 +64,9 @@ type CommitOptions struct {
 	// manifest of the new image will reference the blobs rather than
 	// on-disk layers.
 	BlobDirectory string
-
-	// OnBuild is a list of commands to be run by images based on this image
-	OnBuild []string
-	// Parent is the base image that this image was created by.
-	Parent string
-
+	// EmptyLayer tells the builder to omit the diff for the working
+	// container.
+	EmptyLayer bool
 	// OmitTimestamp forces epoch 0 as created timestamp to allow for
 	// deterministic, content-addressable builds.
 	OmitTimestamp bool
@@ -169,7 +166,7 @@ func (b *Builder) Commit(ctx context.Context, dest types.ImageReference, options
 		}
 	}
 	// Build an image reference from which we can copy the finished image.
-	src, err := b.makeImageRef(options.PreferredManifestType, options.Parent, exportBaseLayers, options.Squash, options.BlobDirectory, options.Compression, options.HistoryTimestamp, options.OmitTimestamp)
+	src, err := b.makeImageRef(options, exportBaseLayers)
 	if err != nil {
 		return imgID, nil, "", errors.Wrapf(err, "error computing layer digests and building metadata for container %q", b.ContainerID)
 	}
diff --git a/vendor/github.com/containers/buildah/image.go b/vendor/github.com/containers/buildah/image.go
index 1cd329c85..215920cc3 100644
--- a/vendor/github.com/containers/buildah/image.go
+++ b/vendor/github.com/containers/buildah/image.go
@@ -56,6 +56,7 @@ type containerImageRef struct {
 	preferredManifestType string
 	exporting             bool
 	squash                bool
+	emptyLayer            bool
 	tarPath               func(path string) (io.ReadCloser, error)
 	parent                string
 	blobDirectory         string
@@ -184,7 +185,7 @@ func (i *containerImageRef) createConfigsAndManifests() (v1.Image, v1.Manifest,
 	if err := json.Unmarshal(i.dconfig, &dimage); err != nil {
 		return v1.Image{}, v1.Manifest{}, docker.V2Image{}, docker.V2S2Manifest{}, err
 	}
-	dimage.Parent = docker.ID(digest.FromString(i.parent))
+	dimage.Parent = docker.ID(i.parent)
 	// Always replace this value, since we're newer than our base image.
 	dimage.Created = created
 	// Clear the list of diffIDs, since we always repopulate it.
@@ -290,6 +291,11 @@ func (i *containerImageRef) NewImageSource(ctx context.Context, sc *types.System
 		if err != nil {
 			return nil, errors.Wrapf(err, "unable to locate layer %q", layerID)
 		}
+		// If we're up to the final layer, but we don't want to include
+		// a diff for it, we're done.
+		if i.emptyLayer && layerID == i.layerID {
+			continue
+		}
 		// If we're not re-exporting the data, and we're reusing layers individually, reuse
 		// the blobsum and diff IDs.
 		if !i.exporting && !i.squash && layerID != i.layerID {
@@ -433,7 +439,7 @@ func (i *containerImageRef) NewImageSource(ctx context.Context, sc *types.System
 		CreatedBy:  i.createdBy,
 		Author:     oimage.Author,
 		Comment:    i.historyComment,
-		EmptyLayer: false,
+		EmptyLayer: i.emptyLayer,
 	}
 	oimage.History = append(oimage.History, onews)
 	dnews := docker.V2S2History{
@@ -441,11 +447,11 @@ func (i *containerImageRef) NewImageSource(ctx context.Context, sc *types.System
 		CreatedBy:  i.createdBy,
 		Author:     dimage.Author,
 		Comment:    i.historyComment,
-		EmptyLayer: false,
+		EmptyLayer: i.emptyLayer,
 	}
 	dimage.History = append(dimage.History, dnews)
 	appendHistory(i.postEmptyLayers)
-	dimage.Parent = docker.ID(digest.FromString(i.parent))
+	dimage.Parent = docker.ID(i.parent)
 
 	// Sanity check that we didn't just create a mismatch between non-empty layers in the
 	// history and the number of diffIDs.
@@ -636,7 +642,7 @@ func (i *containerImageSource) GetBlob(ctx context.Context, blob types.BlobInfo,
 	return ioutils.NewReadCloserWrapper(layerFile, closer), size, nil
 }
 
-func (b *Builder) makeImageRef(manifestType, parent string, exporting bool, squash bool, blobDirectory string, compress archive.Compression, historyTimestamp *time.Time, omitTimestamp bool) (types.ImageReference, error) {
+func (b *Builder) makeImageRef(options CommitOptions, exporting bool) (types.ImageReference, error) {
 	var name reference.Named
 	container, err := b.store.Container(b.ContainerID)
 	if err != nil {
@@ -647,6 +653,7 @@ func (b *Builder) makeImageRef(manifestType, parent string, exporting bool, squa
 			name = parsed
 		}
 	}
+	manifestType := options.PreferredManifestType
 	if manifestType == "" {
 		manifestType = OCIv1ImageManifest
 	}
@@ -659,8 +666,8 @@ func (b *Builder) makeImageRef(manifestType, parent string, exporting bool, squa
 		return nil, errors.Wrapf(err, "error encoding docker-format image configuration %#v", b.Docker)
 	}
 	created := time.Now().UTC()
-	if historyTimestamp != nil {
-		created = historyTimestamp.UTC()
+	if options.HistoryTimestamp != nil {
+		created = options.HistoryTimestamp.UTC()
 	}
 	createdBy := b.CreatedBy()
 	if createdBy == "" {
@@ -670,13 +677,21 @@ func (b *Builder) makeImageRef(manifestType, parent string, exporting bool, squa
 		}
 	}
 
-	if omitTimestamp {
+	if options.OmitTimestamp {
 		created = time.Unix(0, 0)
 	}
 
+	parent := ""
+	if b.FromImageID != "" {
+		parentDigest := digest.NewDigestFromEncoded(digest.Canonical, b.FromImageID)
+		if parentDigest.Validate() == nil {
+			parent = parentDigest.String()
+		}
+	}
+
 	ref := &containerImageRef{
 		store:                 b.store,
-		compression:           compress,
+		compression:           options.Compression,
 		name:                  name,
 		names:                 container.Names,
 		containerID:           container.ID,
@@ -690,10 +705,11 @@ func (b *Builder) makeImageRef(manifestType, parent string, exporting bool, squa
 		annotations:           b.Annotations(),
 		preferredManifestType: manifestType,
 		exporting:             exporting,
-		squash:                squash,
+		squash:                options.Squash,
+		emptyLayer:            options.EmptyLayer,
 		tarPath:               b.tarPath(),
 		parent:                parent,
-		blobDirectory:         blobDirectory,
+		blobDirectory:         options.BlobDirectory,
 		preEmptyLayers:        b.PrependedEmptyLayers,
 		postEmptyLayers:       b.AppendedEmptyLayers,
 	}
diff --git a/vendor/github.com/containers/buildah/imagebuildah/build.go b/vendor/github.com/containers/buildah/imagebuildah/build.go
index b692d3bcf..d9909cdc8 100644
--- a/vendor/github.com/containers/buildah/imagebuildah/build.go
+++ b/vendor/github.com/containers/buildah/imagebuildah/build.go
@@ -28,7 +28,7 @@ import (
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/archive"
 	docker "github.com/fsouza/go-dockerclient"
-	"github.com/opencontainers/image-spec/specs-go/v1"
+	v1 "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/openshift/imagebuilder"
 	"github.com/openshift/imagebuilder/dockerfile/parser"
@@ -215,9 +215,12 @@ type Executor struct {
 	forceRmIntermediateCtrs        bool
 	imageMap                       map[string]string           // Used to map images that we create to handle the AS construct.
 	containerMap                   map[string]*buildah.Builder // Used to map from image names to only-created-for-the-rootfs containers.
+	baseMap                        map[string]bool             // Holds the names of every base image, as given.
+	rootfsMap                      map[string]bool             // Holds the names of every stage whose rootfs is referenced in a COPY or ADD instruction.
 	blobDirectory                  string
 	excludes                       []string
 	unusedArgs                     map[string]struct{}
+	buildArgs                      map[string]string
 }
 
 // StageExecutor bundles up what we need to know when executing one stage of a
@@ -480,6 +483,19 @@ func (s *StageExecutor) volumeCacheRestore() error {
 // imagebuilder tells us the instruction was "ADD" and not "COPY".
 func (s *StageExecutor) Copy(excludes []string, copies ...imagebuilder.Copy) error {
 	for _, copy := range copies {
+		// If the file exists, check to see if it's a symlink.
+		// If it is a symlink, convert to it's target otherwise
+		// the symlink will be overwritten.
+		fileDest, _ := os.Lstat(filepath.Join(s.mountPoint, copy.Dest))
+		if fileDest != nil {
+			if fileDest.Mode()&os.ModeSymlink != 0 {
+				if symLink, err := resolveSymlink(s.mountPoint, copy.Dest); err == nil {
+					copy.Dest = symLink
+				} else {
+					return errors.Wrapf(err, "error reading symbolic link to %q", copy.Dest)
+				}
+			}
+		}
 		if copy.Download {
 			logrus.Debugf("ADD %#v, %#v", excludes, copy)
 		} else {
@@ -590,7 +606,7 @@ func (s *StageExecutor) Run(run imagebuilder.Run, config docker.Config) error {
 // UnrecognizedInstruction is called when we encounter an instruction that the
 // imagebuilder parser didn't understand.
 func (s *StageExecutor) UnrecognizedInstruction(step *imagebuilder.Step) error {
-	errStr := fmt.Sprintf("Build error: Unknown instruction: %q ", step.Command)
+	errStr := fmt.Sprintf("Build error: Unknown instruction: %q ", strings.ToUpper(step.Command))
 	err := fmt.Sprintf(errStr+"%#v", step)
 	if s.executor.ignoreUnrecognizedInstructions {
 		logrus.Debugf(err)
@@ -610,7 +626,7 @@ func (s *StageExecutor) UnrecognizedInstruction(step *imagebuilder.Step) error {
 }
 
 // NewExecutor creates a new instance of the imagebuilder.Executor interface.
-func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
+func NewExecutor(store storage.Store, options BuildOptions, mainNode *parser.Node) (*Executor, error) {
 	excludes, err := imagebuilder.ParseDockerignore(options.ContextDirectory)
 	if err != nil {
 		return nil, err
@@ -656,8 +672,11 @@ func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
 		forceRmIntermediateCtrs:        options.ForceRmIntermediateCtrs,
 		imageMap:                       make(map[string]string),
 		containerMap:                   make(map[string]*buildah.Builder),
+		baseMap:                        make(map[string]bool),
+		rootfsMap:                      make(map[string]bool),
 		blobDirectory:                  options.BlobDirectory,
 		unusedArgs:                     make(map[string]struct{}),
+		buildArgs:                      options.Args,
 	}
 	if exec.err == nil {
 		exec.err = os.Stderr
@@ -679,6 +698,25 @@ func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
 			exec.unusedArgs[arg] = struct{}{}
 		}
 	}
+	for _, line := range mainNode.Children {
+		node := line
+		for node != nil { // tokens on this line, though we only care about the first
+			switch strings.ToUpper(node.Value) { // first token - instruction
+			case "ARG":
+				arg := node.Next
+				if arg != nil {
+					// We have to be careful here - it's either an argument
+					// and value, or just an argument, since they can be
+					// separated by either "=" or whitespace.
+					list := strings.SplitN(arg.Value, "=", 2)
+					if _, stillUnused := exec.unusedArgs[list[0]]; stillUnused {
+						delete(exec.unusedArgs, list[0])
+					}
+				}
+			}
+			break
+		}
+	}
 	return &exec, nil
 }
 
@@ -845,9 +883,9 @@ func (b *Executor) resolveNameToImageRef(output string) (types.ImageReference, e
 	return imageRef, nil
 }
 
-// stepRequiresCommit indicates whether or not the step should be followed by
-// committing the in-progress container to create an intermediate image.
-func (*StageExecutor) stepRequiresCommit(step *imagebuilder.Step) bool {
+// stepRequiresLayer indicates whether or not the step should be followed by
+// committing a layer container when creating an intermediate image.
+func (*StageExecutor) stepRequiresLayer(step *imagebuilder.Step) bool {
 	switch strings.ToUpper(step.Command) {
 	case "ADD", "COPY", "RUN":
 		return true
@@ -875,6 +913,10 @@ func (s *StageExecutor) getImageRootfs(ctx context.Context, stage imagebuilder.S
 func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, base string) (imgID string, ref reference.Canonical, err error) {
 	ib := stage.Builder
 	checkForLayers := s.executor.layers && s.executor.useCache
+	moreStages := s.index < s.stages-1
+	lastStage := !moreStages
+	imageIsUsedLater := moreStages && (s.executor.baseMap[stage.Name] || s.executor.baseMap[fmt.Sprintf("%d", stage.Position)])
+	rootfsIsUsedLater := moreStages && (s.executor.rootfsMap[stage.Name] || s.executor.rootfsMap[fmt.Sprintf("%d", stage.Position)])
 
 	// If the base image's name corresponds to the result of an earlier
 	// stage, substitute that image's ID for the base image's name here.
@@ -896,7 +938,8 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 	// A helper function to only log "COMMIT" as an explicit step if it's
 	// the very last step of a (possibly multi-stage) build.
 	logCommit := func(output string, instruction int) {
-		if instruction < len(children)-1 || s.index < s.stages-1 {
+		moreInstructions := instruction < len(children)-1
+		if moreInstructions || moreStages {
 			return
 		}
 		commitMessage := "COMMIT"
@@ -921,7 +964,7 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 			// squash the contents of the base image.  Whichever is
 			// the case, we need to commit() to create a new image.
 			logCommit(s.output, -1)
-			if imgID, ref, err = s.commit(ctx, ib, getCreatedBy(nil), s.output); err != nil {
+			if imgID, ref, err = s.commit(ctx, ib, s.executor.getCreatedBy(nil), false, s.output); err != nil {
 				return "", nil, errors.Wrapf(err, "error committing base container")
 			}
 		} else {
@@ -936,6 +979,8 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 	}
 
 	for i, node := range children {
+		moreInstructions := i < len(children)-1
+		lastInstruction := !moreInstructions
 		// Resolve any arguments in this instruction.
 		step := ib.Step()
 		if err := step.Resolve(node); err != nil {
@@ -946,30 +991,19 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 			s.executor.log("%s", step.Original)
 		}
 
-		// If this instruction declares an argument, remove it from the
-		// set of arguments that we were passed but which we haven't
-		// yet seen used by the Dockerfile.
-		if step.Command == "arg" {
-			for _, Arg := range step.Args {
-				list := strings.SplitN(Arg, "=", 2)
-				if _, stillUnused := s.executor.unusedArgs[list[0]]; stillUnused {
-					delete(s.executor.unusedArgs, list[0])
-				}
-			}
-		}
-
 		// Check if there's a --from if the step command is COPY or
 		// ADD.  Set copyFrom to point to either the context directory
 		// or the root of the container from the specified stage.
 		s.copyFrom = s.executor.contextDir
 		for _, n := range step.Flags {
-			if strings.Contains(n, "--from") && (step.Command == "copy" || step.Command == "add") {
+			command := strings.ToUpper(step.Command)
+			if strings.Contains(n, "--from") && (command == "COPY" || command == "ADD") {
 				var mountPoint string
 				arr := strings.Split(n, "=")
 				otherStage, ok := s.executor.stages[arr[1]]
 				if !ok {
 					if mountPoint, err = s.getImageRootfs(ctx, stage, arr[1]); err != nil {
-						return "", nil, errors.Errorf("%s --from=%s: no stage or image found with that name", step.Command, arr[1])
+						return "", nil, errors.Errorf("%s --from=%s: no stage or image found with that name", command, arr[1])
 					}
 				} else {
 					mountPoint = otherStage.mountPoint
@@ -984,7 +1018,7 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 		// contents of any volumes declared between now and when we
 		// finish.
 		noRunsRemaining := false
-		if i < len(children)-1 {
+		if moreInstructions {
 			noRunsRemaining = !ib.RequiresStart(&parser.Node{Children: children[i+1:]})
 		}
 
@@ -996,24 +1030,29 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 				logrus.Debugf("%v", errors.Wrapf(err, "error building at step %+v", *step))
 				return "", nil, errors.Wrapf(err, "error building at STEP \"%s\"", step.Message)
 			}
-			if i < len(children)-1 {
+			if moreInstructions {
 				// There are still more instructions to process
 				// for this stage.  Make a note of the
 				// instruction in the history that we'll write
 				// for the image when we eventually commit it.
 				now := time.Now()
-				s.builder.AddPrependedEmptyLayer(&now, getCreatedBy(node), "", "")
+				s.builder.AddPrependedEmptyLayer(&now, s.executor.getCreatedBy(node), "", "")
 				continue
 			} else {
 				// This is the last instruction for this stage,
 				// so we should commit this container to create
-				// an image.
-				logCommit(s.output, i)
-				imgID, ref, err = s.commit(ctx, ib, getCreatedBy(node), s.output)
-				if err != nil {
-					return "", nil, errors.Wrapf(err, "error committing container for step %+v", *step)
+				// an image, but only if it's the last one, or
+				// if it's used as the basis for a later stage.
+				if lastStage || imageIsUsedLater {
+					logCommit(s.output, i)
+					imgID, ref, err = s.commit(ctx, ib, s.executor.getCreatedBy(node), false, s.output)
+					if err != nil {
+						return "", nil, errors.Wrapf(err, "error committing container for step %+v", *step)
+					}
+					logImageID(imgID)
+				} else {
+					imgID = ""
 				}
-				logImageID(imgID)
 				break
 			}
 		}
@@ -1028,18 +1067,14 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 
 		// If we have to commit for this instruction, only assign the
 		// stage's configured output name to the last layer.
-		if i == len(children)-1 {
+		if lastInstruction {
 			commitName = s.output
 		}
 
 		// If we're using the cache, and we've managed to stick with
 		// cached images so far, look for one that matches what we
 		// expect to produce for this instruction.
-		// Only check at steps where we commit, so that we don't
-		// abandon the cache at this step just because we can't find an
-		// image with a history entry in it that we wouldn't have
-		// committed.
-		if checkForLayers && (s.stepRequiresCommit(step) || i == len(children)-1) && !(s.executor.squash && i == len(children)-1 && s.index == s.stages-1) {
+		if checkForLayers && !(s.executor.squash && lastInstruction && lastStage) {
 			cacheID, err = s.layerExists(ctx, node, children[:i])
 			if err != nil {
 				return "", nil, errors.Wrap(err, "error checking if cached image exists from a previous build")
@@ -1059,17 +1094,32 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 			// the last step in this stage, add the name to the
 			// image.
 			imgID = cacheID
-			if commitName != "" && (s.stepRequiresCommit(step) || i == len(children)-1) {
-				logCommit(s.output, i)
+			if commitName != "" {
+				logCommit(commitName, i)
 				if imgID, ref, err = s.copyExistingImage(ctx, cacheID, commitName); err != nil {
 					return "", nil, err
 				}
 				logImageID(imgID)
 			}
 			// Update our working container to be based off of the
-			// cached image, in case we need to read content from
-			// its root filesystem.
-			rebase = true
+			// cached image, if we might need to use it as a basis
+			// for the next instruction, or if we need the root
+			// filesystem to match the image contents for the sake
+			// of a later stage that wants to copy content from it.
+			rebase = moreInstructions || rootfsIsUsedLater
+			// If the instruction would affect our configuration,
+			// process the configuration change so that, if we fall
+			// off the cache path, the filesystem changes from the
+			// last cache image will be all that we need, since we
+			// still don't want to restart using the image's
+			// configuration blob.
+			if !s.stepRequiresLayer(step) {
+				err := ib.Run(step, s, noRunsRemaining)
+				if err != nil {
+					logrus.Debugf("%v", errors.Wrapf(err, "error building at step %+v", *step))
+					return "", nil, errors.Wrapf(err, "error building at STEP \"%s\"", step.Message)
+				}
+			}
 		} else {
 			// If we didn't find a cached image that we could just reuse,
 			// process the instruction directly.
@@ -1078,36 +1128,20 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 				logrus.Debugf("%v", errors.Wrapf(err, "error building at step %+v", *step))
 				return "", nil, errors.Wrapf(err, "error building at STEP \"%s\"", step.Message)
 			}
-			if s.stepRequiresCommit(step) || i == len(children)-1 {
-				// Either this is the last instruction, or
-				// there are more instructions and we need to
-				// create a layer from this one before
-				// continuing.
-				// TODO: only commit for the last instruction
-				// case if we need to use this stage's image as
-				// a base image later, or if we're the final
-				// stage.
-				logCommit(s.output, i)
-				imgID, ref, err = s.commit(ctx, ib, getCreatedBy(node), commitName)
-				if err != nil {
-					return "", nil, errors.Wrapf(err, "error committing container for step %+v", *step)
-				}
-				logImageID(imgID)
-				// We only need to build a new container rootfs
-				// using this image if we plan on making
-				// further changes to it.  Subsequent stages
-				// that just want to use the rootfs as a source
-				// for COPY or ADD will be content with what we
-				// already have.
-				rebase = i < len(children)-1
-			} else {
-				// There are still more instructions to process
-				// for this stage, and we don't need to commit
-				// here.  Make a note of the instruction in the
-				// history for the next commit.
-				now := time.Now()
-				s.builder.AddPrependedEmptyLayer(&now, getCreatedBy(node), "", "")
+			// Create a new image, maybe with a new layer.
+			logCommit(s.output, i)
+			imgID, ref, err = s.commit(ctx, ib, s.executor.getCreatedBy(node), !s.stepRequiresLayer(step), commitName)
+			if err != nil {
+				return "", nil, errors.Wrapf(err, "error committing container for step %+v", *step)
 			}
+			logImageID(imgID)
+			// We only need to build a new container rootfs
+			// using this image if we plan on making
+			// further changes to it.  Subsequent stages
+			// that just want to use the rootfs as a source
+			// for COPY or ADD will be content with what we
+			// already have.
+			rebase = moreInstructions
 		}
 
 		if rebase {
@@ -1122,8 +1156,6 @@ func (s *StageExecutor) Execute(ctx context.Context, stage imagebuilder.Stage, b
 			// creating a new working container with the
 			// just-committed or updated cached image as its new
 			// base image.
-			// TODO: only create a new container if we know that
-			// we'll need the updated root filesystem.
 			if _, err := s.prepare(ctx, stage, imgID, false, true); err != nil {
 				return "", nil, errors.Wrap(err, "error preparing container for next step")
 			}
@@ -1195,13 +1227,13 @@ func (s *StageExecutor) layerExists(ctx context.Context, currNode *parser.Node,
 		// it means that this image is potentially a cached intermediate image from a previous
 		// build. Next we double check that the history of this image is equivalent to the previous
 		// lines in the Dockerfile up till the point we are at in the build.
-		if layer.Parent == s.executor.topLayers[len(s.executor.topLayers)-1] {
+		if layer.Parent == s.executor.topLayers[len(s.executor.topLayers)-1] || layer.ID == s.executor.topLayers[len(s.executor.topLayers)-1] {
 			history, err := s.executor.getImageHistory(ctx, image.ID)
 			if err != nil {
 				return "", errors.Wrapf(err, "error getting history of %q", image.ID)
 			}
 			// children + currNode is the point of the Dockerfile we are currently at.
-			if historyMatches(append(children, currNode), history) {
+			if s.executor.historyMatches(append(children, currNode), history) {
 				// This checks if the files copied during build have been changed if the node is
 				// a COPY or ADD command.
 				filesMatch, err := s.copiedFilesMatch(currNode, history[len(history)-1].Created)
@@ -1225,21 +1257,26 @@ func (b *Executor) getImageHistory(ctx context.Context, imageID string) ([]v1.Hi
 	}
 	ref, err := imageRef.NewImage(ctx, nil)
 	if err != nil {
-		return nil, errors.Wrap(err, "error creating new image from reference")
+		return nil, errors.Wrapf(err, "error creating new image from reference to image %q", imageID)
 	}
+	defer ref.Close()
 	oci, err := ref.OCIConfig(ctx)
 	if err != nil {
-		return nil, errors.Wrapf(err, "error getting oci config of image %q", imageID)
+		return nil, errors.Wrapf(err, "error getting possibly-converted OCI config of image %q", imageID)
 	}
 	return oci.History, nil
 }
 
 // getCreatedBy returns the command the image at node will be created by.
-func getCreatedBy(node *parser.Node) string {
+func (b *Executor) getCreatedBy(node *parser.Node) string {
 	if node == nil {
 		return "/bin/sh"
 	}
 	if node.Value == "run" {
+		buildArgs := b.getBuildArgs()
+		if buildArgs != "" {
+			return "|" + strconv.Itoa(len(strings.Split(buildArgs, " "))) + " " + buildArgs + " /bin/sh -c " + node.Original[4:]
+		}
 		return "/bin/sh -c " + node.Original[4:]
 	}
 	return "/bin/sh -c #(nop) " + node.Original
@@ -1249,12 +1286,23 @@ func getCreatedBy(node *parser.Node) string {
 // in the Dockerfile till the point of build we are at.
 // Used to verify whether a cache of the intermediate image exists and whether
 // to run the build again.
-func historyMatches(children []*parser.Node, history []v1.History) bool {
+func (b *Executor) historyMatches(children []*parser.Node, history []v1.History) bool {
 	i := len(history) - 1
 	for j := len(children) - 1; j >= 0; j-- {
 		instruction := children[j].Original
 		if children[j].Value == "run" {
 			instruction = instruction[4:]
+			buildArgs := b.getBuildArgs()
+			// If a previous image was built with some build-args but the new build process doesn't have any build-args
+			// specified, so compare the lengths of the old instruction with the current one
+			// 11 is the length of "/bin/sh -c " that is used to run the run commands
+			if buildArgs == "" && len(history[i].CreatedBy) > len(instruction)+11 {
+				return false
+			}
+			// There are build-args, so check if anything with the build-args has changed
+			if buildArgs != "" && !strings.Contains(history[i].CreatedBy, buildArgs) {
+				return false
+			}
 		}
 		if !strings.Contains(history[i].CreatedBy, instruction) {
 			return false
@@ -1264,6 +1312,18 @@ func historyMatches(children []*parser.Node, history []v1.History) bool {
 	return true
 }
 
+// getBuildArgs returns a string of the build-args specified during the build process
+// it excludes any build-args that were not used in the build process
+func (b *Executor) getBuildArgs() string {
+	var buildArgs []string
+	for k, v := range b.buildArgs {
+		if _, ok := b.unusedArgs[k]; !ok {
+			buildArgs = append(buildArgs, k+"="+v)
+		}
+	}
+	return strings.Join(buildArgs, " ")
+}
+
 // getFilesToCopy goes through node to get all the src files that are copied, added or downloaded.
 // It is possible for the Dockerfile to have src as hom*, which means all files that have hom as a prefix.
 // Another format is hom?.txt, which means all files that have that name format with the ? replaced by another character.
@@ -1348,7 +1408,7 @@ func urlContentModified(url string, historyTime *time.Time) (bool, error) {
 
 // commit writes the container's contents to an image, using a passed-in tag as
 // the name if there is one, generating a unique ID-based one otherwise.
-func (s *StageExecutor) commit(ctx context.Context, ib *imagebuilder.Builder, createdBy, output string) (string, reference.Canonical, error) {
+func (s *StageExecutor) commit(ctx context.Context, ib *imagebuilder.Builder, createdBy string, emptyLayer bool, output string) (string, reference.Canonical, error) {
 	var imageRef types.ImageReference
 	if output != "" {
 		imageRef2, err := s.executor.resolveNameToImageRef(output)
@@ -1438,8 +1498,8 @@ func (s *StageExecutor) commit(ctx context.Context, ib *imagebuilder.Builder, cr
 		PreferredManifestType: s.executor.outputFormat,
 		SystemContext:         s.executor.systemContext,
 		Squash:                s.executor.squash,
+		EmptyLayer:            emptyLayer,
 		BlobDirectory:         s.executor.blobDirectory,
-		Parent:                s.builder.FromImageID,
 	}
 	imgID, _, manifestDigest, err := s.builder.Commit(ctx, imageRef, options)
 	if err != nil {
@@ -1510,6 +1570,46 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 	}
 	defer cleanup()
 
+	// Build maps of every named base image and every referenced stage root
+	// filesystem.  Individual stages can use them to determine whether or
+	// not they can skip certain steps near the end of their stages.
+	for _, stage := range stages {
+		node := stage.Node // first line
+		for node != nil {  // each line
+			for _, child := range node.Children { // tokens on this line, though we only care about the first
+				switch strings.ToUpper(child.Value) { // first token - instruction
+				case "FROM":
+					if child.Next != nil { // second token on this line
+						base := child.Next.Value
+						if base != "scratch" {
+							// TODO: this didn't undergo variable and arg
+							// expansion, so if the AS clause in another
+							// FROM instruction uses argument values,
+							// we might not record the right value here.
+							b.baseMap[base] = true
+							logrus.Debugf("base: %q", base)
+						}
+					}
+				case "ADD", "COPY":
+					for _, flag := range child.Flags { // flags for this instruction
+						if strings.HasPrefix(flag, "--from=") {
+							// TODO: this didn't undergo variable and
+							// arg expansion, so if the previous stage
+							// was named using argument values, we might
+							// not record the right value here.
+							rootfs := flag[7:]
+							b.rootfsMap[rootfs] = true
+							logrus.Debugf("rootfs: %q", rootfs)
+						}
+					}
+				}
+				break
+			}
+			node = node.Next // next line
+		}
+	}
+
+	// Run through the build stages, one at a time.
 	for stageIndex, stage := range stages {
 		var lastErr error
 
@@ -1555,7 +1655,7 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 
 		// If this is an intermediate stage, make a note of the ID, so
 		// that we can look it up later.
-		if stageIndex < len(stages)-1 {
+		if stageIndex < len(stages)-1 && imageID != "" {
 			b.imageMap[stage.Name] = imageID
 			// We're not populating the cache with intermediate
 			// images, so add this one to the list of images that
@@ -1671,7 +1771,7 @@ func BuildDockerfiles(ctx context.Context, store storage.Store, options BuildOpt
 		}
 		mainNode.Children = append(mainNode.Children, additionalNode.Children...)
 	}
-	exec, err := NewExecutor(store, options)
+	exec, err := NewExecutor(store, options, mainNode)
 	if err != nil {
 		return "", nil, errors.Wrapf(err, "error creating build executor")
 	}
diff --git a/vendor/github.com/containers/buildah/imagebuildah/chroot_symlink.go b/vendor/github.com/containers/buildah/imagebuildah/chroot_symlink.go
index 86bf7653b..0789c2b3c 100644
--- a/vendor/github.com/containers/buildah/imagebuildah/chroot_symlink.go
+++ b/vendor/github.com/containers/buildah/imagebuildah/chroot_symlink.go
@@ -129,20 +129,20 @@ func resolveModifiedTime(rootdir, filename, historyTime string) (bool, error) {
 func modTimeIsGreater(rootdir, path string, historyTime string) (bool, error) {
 	var timeIsGreater bool
 
-	// the Walk below doesn't work if rootdir and path are equal
-	if rootdir == path {
-		return false, nil
-	}
-
 	// Convert historyTime from string to time.Time for comparison
 	histTime, err := time.Parse(time.RFC3339Nano, historyTime)
 	if err != nil {
 		return false, errors.Wrapf(err, "error converting string to time.Time %q", historyTime)
 	}
+
+	// Since we are chroot in rootdir, we want a relative path, i.e (path - rootdir)
+	relPath, err := filepath.Rel(rootdir, path)
+	if err != nil {
+		return false, errors.Wrapf(err, "error making path %q relative to %q", path, rootdir)
+	}
+
 	// Walk the file tree and check the time stamps.
-	// Since we are chroot in rootdir, only want the path of the actual filename, i.e path - rootdir.
-	// +1 to account for the extra "/" (e.g rootdir=/home/user/mydir, path=/home/user/mydir/myfile.json)
-	err = filepath.Walk(path[len(rootdir)+1:], func(path string, info os.FileInfo, err error) error {
+	err = filepath.Walk(relPath, func(path string, info os.FileInfo, err error) error {
 		// If using cached images, it is possible for files that are being copied to come from
 		// previous build stages. But if using cached images, then the copied file won't exist
 		// since a container won't have been created for the previous build stage and info will be nil.
@@ -154,6 +154,9 @@ func modTimeIsGreater(rootdir, path string, historyTime string) (bool, error) {
 		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
 			// Evaluate any symlink that occurs to get updated modified information
 			resolvedPath, err := filepath.EvalSymlinks(path)
+			if err != nil && os.IsNotExist(err) {
+				return errors.Wrapf(errDanglingSymlink, "%q", path)
+			}
 			if err != nil {
 				return errors.Wrapf(err, "error evaluating symlink %q", path)
 			}
@@ -169,7 +172,12 @@ func modTimeIsGreater(rootdir, path string, historyTime string) (bool, error) {
 		}
 		return nil
 	})
+
 	if err != nil {
+		// if error is due to dangling symlink, ignore error and return nil
+		if errors.Cause(err) == errDanglingSymlink {
+			return false, nil
+		}
 		return false, errors.Wrapf(err, "error walking file tree %q", path)
 	}
 	return timeIsGreater, err
diff --git a/vendor/github.com/containers/buildah/imagebuildah/errors.go b/vendor/github.com/containers/buildah/imagebuildah/errors.go
new file mode 100644
index 000000000..cf299656b
--- /dev/null
+++ b/vendor/github.com/containers/buildah/imagebuildah/errors.go
@@ -0,0 +1,7 @@
+package imagebuildah
+
+import "errors"
+
+var (
+	errDanglingSymlink = errors.New("error evaluating dangling symlink")
+)
diff --git a/vendor/github.com/containers/buildah/pkg/cli/common.go b/vendor/github.com/containers/buildah/pkg/cli/common.go
index 6c4d14303..7fa0a7777 100644
--- a/vendor/github.com/containers/buildah/pkg/cli/common.go
+++ b/vendor/github.com/containers/buildah/pkg/cli/common.go
@@ -89,6 +89,7 @@ type FromAndBudResults struct {
 	DNSSearch    []string
 	DNSServers   []string
 	DNSOptions   []string
+	HttpProxy    bool
 	Isolation    string
 	Memory       string
 	MemorySwap   string
@@ -182,6 +183,7 @@ func GetFromAndBudFlags(flags *FromAndBudResults, usernsResults *UserNSResults,
 	fs.StringSliceVar(&flags.DNSSearch, "dns-search", []string{}, "Set custom DNS search domains")
 	fs.StringSliceVar(&flags.DNSServers, "dns", []string{}, "Set custom DNS servers")
 	fs.StringSliceVar(&flags.DNSOptions, "dns-option", []string{}, "Set custom DNS options")
+	fs.BoolVar(&flags.HttpProxy, "http-proxy", true, "pass thru HTTP Proxy environment variables")
 	fs.StringVar(&flags.Isolation, "isolation", DefaultIsolation(), "`type` of process isolation to use. Use BUILDAH_ISOLATION environment variable to override.")
 	fs.StringVarP(&flags.Memory, "memory", "m", "", "memory limit (format: <number>[<unit>], where unit = b, k, m or g)")
 	fs.StringVar(&flags.MemorySwap, "memory-swap", "", "swap limit equal to memory plus swap: '-1' to enable unlimited swap")
diff --git a/vendor/github.com/containers/buildah/pkg/parse/parse.go b/vendor/github.com/containers/buildah/pkg/parse/parse.go
index c4e3e4264..cc85136fd 100644
--- a/vendor/github.com/containers/buildah/pkg/parse/parse.go
+++ b/vendor/github.com/containers/buildah/pkg/parse/parse.go
@@ -86,6 +86,7 @@ func CommonBuildOptions(c *cobra.Command) (*buildah.CommonBuildOptions, error) {
 	cpuPeriod, _ := c.Flags().GetUint64("cpu-period")
 	cpuQuota, _ := c.Flags().GetInt64("cpu-quota")
 	cpuShares, _ := c.Flags().GetUint64("cpu-shared")
+	httpProxy, _ := c.Flags().GetBool("http-proxy")
 	ulimit, _ := c.Flags().GetStringSlice("ulimit")
 	commonOpts := &buildah.CommonBuildOptions{
 		AddHost:      addHost,
@@ -98,6 +99,7 @@ func CommonBuildOptions(c *cobra.Command) (*buildah.CommonBuildOptions, error) {
 		DNSSearch:    dnsSearch,
 		DNSServers:   dnsServers,
 		DNSOptions:   dnsOptions,
+		HTTPProxy:    httpProxy,
 		Memory:       memoryLimit,
 		MemorySwap:   memorySwap,
 		ShmSize:      c.Flag("shm-size").Value.String(),
diff --git a/vendor/github.com/containers/buildah/pkg/unshare/unshare.go b/vendor/github.com/containers/buildah/pkg/unshare/unshare.go
index 5b2e7d7d1..33232740e 100644
--- a/vendor/github.com/containers/buildah/pkg/unshare/unshare.go
+++ b/vendor/github.com/containers/buildah/pkg/unshare/unshare.go
@@ -3,6 +3,7 @@
 package unshare
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
 	"io"
@@ -15,7 +16,7 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/containers/buildah/util"
+	"github.com/containers/storage/pkg/idtools"
 	"github.com/containers/storage/pkg/reexec"
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
@@ -157,7 +158,7 @@ func (c *Cmd) Start() error {
 		}
 
 		if len(c.UidMappings) == 0 || len(c.GidMappings) == 0 {
-			uidmap, gidmap, err := util.GetHostIDMappings("")
+			uidmap, gidmap, err := GetHostIDMappings("")
 			if err != nil {
 				fmt.Fprintf(continueWrite, "error reading ID mappings in parent: %v", err)
 				return errors.Wrapf(err, "error reading ID mappings in parent")
@@ -352,7 +353,7 @@ func MaybeReexecUsingUserNamespace(evenForRoot bool) {
 		// Read the set of ID mappings that we're allowed to use.  Each
 		// range in /etc/subuid and /etc/subgid file is a starting host
 		// ID and a range size.
-		uidmap, gidmap, err = util.GetSubIDMappings(me.Username, me.Username)
+		uidmap, gidmap, err = GetSubIDMappings(me.Username, me.Username)
 		bailOnError(err, "error reading allowed ID mappings")
 		if len(uidmap) == 0 {
 			logrus.Warnf("Found no UID ranges set aside for user %q in /etc/subuid.", me.Username)
@@ -384,7 +385,7 @@ func MaybeReexecUsingUserNamespace(evenForRoot bool) {
 			return
 		}
 		// Read the set of ID mappings that we're currently using.
-		uidmap, gidmap, err = util.GetHostIDMappings("")
+		uidmap, gidmap, err = GetHostIDMappings("")
 		bailOnError(err, "error reading current ID mappings")
 		// Just reuse them.
 		for i := range uidmap {
@@ -404,6 +405,16 @@ func MaybeReexecUsingUserNamespace(evenForRoot bool) {
 	err = os.Setenv(UsernsEnvName, "1")
 	bailOnError(err, "error setting %s=1 in environment", UsernsEnvName)
 
+	// Set the default isolation type to use the "rootless" method.
+	if _, present := os.LookupEnv("BUILDAH_ISOLATION"); !present {
+		if err = os.Setenv("BUILDAH_ISOLATION", "rootless"); err != nil {
+			if err := os.Setenv("BUILDAH_ISOLATION", "rootless"); err != nil {
+				logrus.Errorf("error setting BUILDAH_ISOLATION=rootless in environment: %v", err)
+				os.Exit(1)
+			}
+		}
+	}
+
 	// Reuse our stdio.
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
@@ -446,3 +457,89 @@ func ExecRunnable(cmd Runnable) {
 	}
 	os.Exit(0)
 }
+
+// getHostIDMappings reads mappings from the named node under /proc.
+func getHostIDMappings(path string) ([]specs.LinuxIDMapping, error) {
+	var mappings []specs.LinuxIDMapping
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, errors.Wrapf(err, "error reading ID mappings from %q", path)
+	}
+	defer f.Close()
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		line := scanner.Text()
+		fields := strings.Fields(line)
+		if len(fields) != 3 {
+			return nil, errors.Errorf("line %q from %q has %d fields, not 3", line, path, len(fields))
+		}
+		cid, err := strconv.ParseUint(fields[0], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing container ID value %q from line %q in %q", fields[0], line, path)
+		}
+		hid, err := strconv.ParseUint(fields[1], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing host ID value %q from line %q in %q", fields[1], line, path)
+		}
+		size, err := strconv.ParseUint(fields[2], 10, 32)
+		if err != nil {
+			return nil, errors.Wrapf(err, "error parsing size value %q from line %q in %q", fields[2], line, path)
+		}
+		mappings = append(mappings, specs.LinuxIDMapping{ContainerID: uint32(cid), HostID: uint32(hid), Size: uint32(size)})
+	}
+	return mappings, nil
+}
+
+// GetHostIDMappings reads mappings for the specified process (or the current
+// process if pid is "self" or an empty string) from the kernel.
+func GetHostIDMappings(pid string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
+	if pid == "" {
+		pid = "self"
+	}
+	uidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/uid_map", pid))
+	if err != nil {
+		return nil, nil, err
+	}
+	gidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/gid_map", pid))
+	if err != nil {
+		return nil, nil, err
+	}
+	return uidmap, gidmap, nil
+}
+
+// GetSubIDMappings reads mappings from /etc/subuid and /etc/subgid.
+func GetSubIDMappings(user, group string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
+	mappings, err := idtools.NewIDMappings(user, group)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "error reading subuid mappings for user %q and subgid mappings for group %q", user, group)
+	}
+	var uidmap, gidmap []specs.LinuxIDMapping
+	for _, m := range mappings.UIDs() {
+		uidmap = append(uidmap, specs.LinuxIDMapping{
+			ContainerID: uint32(m.ContainerID),
+			HostID:      uint32(m.HostID),
+			Size:        uint32(m.Size),
+		})
+	}
+	for _, m := range mappings.GIDs() {
+		gidmap = append(gidmap, specs.LinuxIDMapping{
+			ContainerID: uint32(m.ContainerID),
+			HostID:      uint32(m.HostID),
+			Size:        uint32(m.Size),
+		})
+	}
+	return uidmap, gidmap, nil
+}
+
+// ParseIDMappings parses mapping triples.
+func ParseIDMappings(uidmap, gidmap []string) ([]idtools.IDMap, []idtools.IDMap, error) {
+	uid, err := idtools.ParseIDMap(uidmap, "userns-uid-map")
+	if err != nil {
+		return nil, nil, err
+	}
+	gid, err := idtools.ParseIDMap(gidmap, "userns-gid-map")
+	if err != nil {
+		return nil, nil, err
+	}
+	return uid, gid, nil
+}
diff --git a/vendor/github.com/containers/buildah/pkg/unshare/unshare_unsupported.go b/vendor/github.com/containers/buildah/pkg/unshare/unshare_unsupported.go
index d8d5f6f7a..bf4d567b8 100644
--- a/vendor/github.com/containers/buildah/pkg/unshare/unshare_unsupported.go
+++ b/vendor/github.com/containers/buildah/pkg/unshare/unshare_unsupported.go
@@ -4,6 +4,9 @@ package unshare
 
 import (
 	"os"
+
+	"github.com/containers/storage/pkg/idtools"
+	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
 const (
@@ -29,3 +32,14 @@ func RootlessEnv() []string {
 // MaybeReexecUsingUserNamespace re-exec the process in a new namespace
 func MaybeReexecUsingUserNamespace(evenForRoot bool) {
 }
+
+// GetHostIDMappings reads mappings for the specified process (or the current
+// process if pid is "self" or an empty string) from the kernel.
+func GetHostIDMappings(pid string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
+	return nil, nil, nil
+}
+
+// ParseIDMappings parses mapping triples.
+func ParseIDMappings(uidmap, gidmap []string) ([]idtools.IDMap, []idtools.IDMap, error) {
+	return nil, nil, nil
+}
diff --git a/vendor/github.com/containers/buildah/run.go b/vendor/github.com/containers/buildah/run.go
index 5d28644d7..00eac8e39 100644
--- a/vendor/github.com/containers/buildah/run.go
+++ b/vendor/github.com/containers/buildah/run.go
@@ -865,7 +865,7 @@ func setupNamespaces(g *generate.Generator, namespaceOptions NamespaceOptions, i
 		if err := g.AddOrReplaceLinuxNamespace(specs.UserNamespace, ""); err != nil {
 			return false, nil, false, errors.Wrapf(err, "error adding new %q namespace for run", string(specs.UserNamespace))
 		}
-		hostUidmap, hostGidmap, err := util.GetHostIDMappings("")
+		hostUidmap, hostGidmap, err := unshare.GetHostIDMappings("")
 		if err != nil {
 			return false, nil, false, err
 		}
@@ -983,6 +983,24 @@ func (b *Builder) configureUIDGID(g *generate.Generator, mountPoint string, opti
 
 func (b *Builder) configureEnvironment(g *generate.Generator, options RunOptions) {
 	g.ClearProcessEnv()
+	if b.CommonBuildOpts.HTTPProxy {
+		for _, envSpec := range []string{
+			"http_proxy",
+			"HTTP_PROXY",
+			"https_proxy",
+			"HTTPS_PROXY",
+			"ftp_proxy",
+			"FTP_PROXY",
+			"no_proxy",
+			"NO_PROXY",
+		} {
+			envVal := os.Getenv(envSpec)
+			if envVal != "" {
+				g.AddProcessEnv(envSpec, envVal)
+			}
+		}
+	}
+
 	for _, envSpec := range append(b.Env(), options.Env...) {
 		env := strings.SplitN(envSpec, "=", 2)
 		if len(env) > 1 {
diff --git a/vendor/github.com/containers/buildah/selinux.go b/vendor/github.com/containers/buildah/selinux.go
index 2b850cf9f..e64eb6112 100644
--- a/vendor/github.com/containers/buildah/selinux.go
+++ b/vendor/github.com/containers/buildah/selinux.go
@@ -4,9 +4,12 @@ package buildah
 
 import (
 	"github.com/opencontainers/runtime-tools/generate"
+	selinux "github.com/opencontainers/selinux/go-selinux"
 )
 
 func setupSelinux(g *generate.Generator, processLabel, mountLabel string) {
-	g.SetProcessSelinuxLabel(processLabel)
-	g.SetLinuxMountLabel(mountLabel)
+	if processLabel != "" && selinux.GetEnabled() {
+		g.SetProcessSelinuxLabel(processLabel)
+		g.SetLinuxMountLabel(mountLabel)
+	}
 }
diff --git a/vendor/github.com/containers/buildah/util/util.go b/vendor/github.com/containers/buildah/util/util.go
index 7f3bbaef4..698d79a81 100644
--- a/vendor/github.com/containers/buildah/util/util.go
+++ b/vendor/github.com/containers/buildah/util/util.go
@@ -1,13 +1,11 @@
 package util
 
 import (
-	"bufio"
 	"fmt"
 	"io"
 	"net/url"
 	"os"
 	"path"
-	"strconv"
 	"strings"
 	"syscall"
 
@@ -18,7 +16,6 @@ import (
 	"github.com/containers/image/transports"
 	"github.com/containers/image/types"
 	"github.com/containers/storage"
-	"github.com/containers/storage/pkg/idtools"
 	"github.com/docker/distribution/registry/api/errcode"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
@@ -299,92 +296,6 @@ func GetHostRootIDs(spec *specs.Spec) (uint32, uint32, error) {
 	return GetHostIDs(spec.Linux.UIDMappings, spec.Linux.GIDMappings, 0, 0)
 }
 
-// getHostIDMappings reads mappings from the named node under /proc.
-func getHostIDMappings(path string) ([]specs.LinuxIDMapping, error) {
-	var mappings []specs.LinuxIDMapping
-	f, err := os.Open(path)
-	if err != nil {
-		return nil, errors.Wrapf(err, "error reading ID mappings from %q", path)
-	}
-	defer f.Close()
-	scanner := bufio.NewScanner(f)
-	for scanner.Scan() {
-		line := scanner.Text()
-		fields := strings.Fields(line)
-		if len(fields) != 3 {
-			return nil, errors.Errorf("line %q from %q has %d fields, not 3", line, path, len(fields))
-		}
-		cid, err := strconv.ParseUint(fields[0], 10, 32)
-		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing container ID value %q from line %q in %q", fields[0], line, path)
-		}
-		hid, err := strconv.ParseUint(fields[1], 10, 32)
-		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing host ID value %q from line %q in %q", fields[1], line, path)
-		}
-		size, err := strconv.ParseUint(fields[2], 10, 32)
-		if err != nil {
-			return nil, errors.Wrapf(err, "error parsing size value %q from line %q in %q", fields[2], line, path)
-		}
-		mappings = append(mappings, specs.LinuxIDMapping{ContainerID: uint32(cid), HostID: uint32(hid), Size: uint32(size)})
-	}
-	return mappings, nil
-}
-
-// GetHostIDMappings reads mappings for the specified process (or the current
-// process if pid is "self" or an empty string) from the kernel.
-func GetHostIDMappings(pid string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
-	if pid == "" {
-		pid = "self"
-	}
-	uidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/uid_map", pid))
-	if err != nil {
-		return nil, nil, err
-	}
-	gidmap, err := getHostIDMappings(fmt.Sprintf("/proc/%s/gid_map", pid))
-	if err != nil {
-		return nil, nil, err
-	}
-	return uidmap, gidmap, nil
-}
-
-// GetSubIDMappings reads mappings from /etc/subuid and /etc/subgid.
-func GetSubIDMappings(user, group string) ([]specs.LinuxIDMapping, []specs.LinuxIDMapping, error) {
-	mappings, err := idtools.NewIDMappings(user, group)
-	if err != nil {
-		return nil, nil, errors.Wrapf(err, "error reading subuid mappings for user %q and subgid mappings for group %q", user, group)
-	}
-	var uidmap, gidmap []specs.LinuxIDMapping
-	for _, m := range mappings.UIDs() {
-		uidmap = append(uidmap, specs.LinuxIDMapping{
-			ContainerID: uint32(m.ContainerID),
-			HostID:      uint32(m.HostID),
-			Size:        uint32(m.Size),
-		})
-	}
-	for _, m := range mappings.GIDs() {
-		gidmap = append(gidmap, specs.LinuxIDMapping{
-			ContainerID: uint32(m.ContainerID),
-			HostID:      uint32(m.HostID),
-			Size:        uint32(m.Size),
-		})
-	}
-	return uidmap, gidmap, nil
-}
-
-// ParseIDMappings parses mapping triples.
-func ParseIDMappings(uidmap, gidmap []string) ([]idtools.IDMap, []idtools.IDMap, error) {
-	uid, err := idtools.ParseIDMap(uidmap, "userns-uid-map")
-	if err != nil {
-		return nil, nil, err
-	}
-	gid, err := idtools.ParseIDMap(gidmap, "userns-gid-map")
-	if err != nil {
-		return nil, nil, err
-	}
-	return uid, gid, nil
-}
-
 // GetPolicyContext sets up, initializes and returns a new context for the specified policy
 func GetPolicyContext(ctx *types.SystemContext) (*signature.PolicyContext, error) {
 	policy, err := signature.DefaultPolicy(ctx)
diff --git a/vendor/github.com/containers/buildah/vendor.conf b/vendor/github.com/containers/buildah/vendor.conf
index a77130acb..bec681e5c 100644
--- a/vendor/github.com/containers/buildah/vendor.conf
+++ b/vendor/github.com/containers/buildah/vendor.conf
@@ -8,7 +8,7 @@ github.com/vbauerster/mpb v3.3.4
 github.com/mattn/go-isatty v0.0.4
 github.com/VividCortex/ewma v1.1.1
 github.com/boltdb/bolt v1.3.1
-github.com/containers/storage v1.12.2
+github.com/containers/storage v1.12.3
 github.com/docker/distribution 5f6282db7d65e6d72ad7c2cc66310724a57be716
 github.com/docker/docker 54dddadc7d5d89fe0be88f76979f6f6ab0dede83
 github.com/docker/docker-credential-helpers v0.6.1
diff --git a/vendor/github.com/containers/storage/drivers/overlay/overlay.go b/vendor/github.com/containers/storage/drivers/overlay/overlay.go
index 69036a5c1..5d667d8c6 100644
--- a/vendor/github.com/containers/storage/drivers/overlay/overlay.go
+++ b/vendor/github.com/containers/storage/drivers/overlay/overlay.go
@@ -16,7 +16,7 @@ import (
 	"sync"
 	"syscall"
 
-	"github.com/containers/storage/drivers"
+	graphdriver "github.com/containers/storage/drivers"
 	"github.com/containers/storage/drivers/overlayutils"
 	"github.com/containers/storage/drivers/quota"
 	"github.com/containers/storage/pkg/archive"
@@ -320,6 +320,8 @@ func supportsOverlay(home string, homeMagic graphdriver.FsMagic, rootUID, rootGI
 		mergedDir := filepath.Join(layerDir, "merged")
 		lower1Dir := filepath.Join(layerDir, "lower1")
 		lower2Dir := filepath.Join(layerDir, "lower2")
+		upperDir := filepath.Join(layerDir, "upper")
+		workDir := filepath.Join(layerDir, "work")
 		defer func() {
 			// Permitted to fail, since the various subdirectories
 			// can be empty or not even there, and the home might
@@ -331,7 +333,9 @@ func supportsOverlay(home string, homeMagic graphdriver.FsMagic, rootUID, rootGI
 		_ = idtools.MkdirAs(mergedDir, 0700, rootUID, rootGID)
 		_ = idtools.MkdirAs(lower1Dir, 0700, rootUID, rootGID)
 		_ = idtools.MkdirAs(lower2Dir, 0700, rootUID, rootGID)
-		flags := fmt.Sprintf("lowerdir=%s:%s", lower1Dir, lower2Dir)
+		_ = idtools.MkdirAs(upperDir, 0700, rootUID, rootGID)
+		_ = idtools.MkdirAs(workDir, 0700, rootUID, rootGID)
+		flags := fmt.Sprintf("lowerdir=%s:%s,upperdir=%s,workdir=%s", lower1Dir, lower2Dir, upperDir, workDir)
 		if len(flags) < unix.Getpagesize() {
 			err := mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags)
 			if err == nil {
@@ -341,7 +345,7 @@ func supportsOverlay(home string, homeMagic graphdriver.FsMagic, rootUID, rootGI
 				logrus.Debugf("overlay test mount with multiple lowers failed %v", err)
 			}
 		}
-		flags = fmt.Sprintf("lowerdir=%s", lower1Dir)
+		flags = fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lower1Dir, upperDir, workDir)
 		if len(flags) < unix.Getpagesize() {
 			err := mountFrom(filepath.Dir(home), "overlay", mergedDir, "overlay", 0, flags)
 			if err == nil {
@@ -677,6 +681,40 @@ func (d *Driver) Remove(id string) error {
 	return nil
 }
 
+// recreateSymlinks goes through the driver's home directory and checks if the diff directory
+// under each layer has a symlink created for it under the linkDir. If the symlink does not
+// exist, it creates them
+func (d *Driver) recreateSymlinks() error {
+	// List all the directories under the home directory
+	dirs, err := ioutil.ReadDir(d.home)
+	if err != nil {
+		return fmt.Errorf("error reading driver home directory %q: %v", d.home, err)
+	}
+	for _, dir := range dirs {
+		// Skip over the linkDir
+		if dir.Name() == linkDir || dir.Mode().IsRegular() {
+			continue
+		}
+		// Read the "link" file under each layer to get the name of the symlink
+		data, err := ioutil.ReadFile(path.Join(d.dir(dir.Name()), "link"))
+		if err != nil {
+			return fmt.Errorf("error reading name of symlink for %q: %v", dir, err)
+		}
+		linkPath := path.Join(d.home, linkDir, strings.Trim(string(data), "\n"))
+		// Check if the symlink exists, and if it doesn't create it again with the name we
+		// got from the "link" file
+		_, err = os.Stat(linkPath)
+		if err != nil && os.IsNotExist(err) {
+			if err := os.Symlink(path.Join("..", dir.Name(), "diff"), linkPath); err != nil {
+				return err
+			}
+		} else if err != nil {
+			return fmt.Errorf("error trying to stat %q: %v", linkPath, err)
+		}
+	}
+	return nil
+}
+
 // Get creates and mounts the required file system for the given id and returns the mount path.
 func (d *Driver) Get(id string, options graphdriver.MountOpts) (_ string, retErr error) {
 	return d.get(id, false, options)
@@ -732,7 +770,16 @@ func (d *Driver) get(id string, disableShifting bool, options graphdriver.MountO
 				}
 				lower = ""
 			}
-			if lower == "" {
+			// if it is a "not found" error, that means the symlinks were lost in a sudden reboot
+			// so call the recreateSymlinks function to go through all the layer dirs and recreate
+			// the symlinks with the name from their respective "link" files
+			if lower == "" && os.IsNotExist(err) {
+				logrus.Warnf("Can't stat lower layer %q because it does not exist. Going through storage to recreate the missing symlinks.", newpath)
+				if err := d.recreateSymlinks(); err != nil {
+					return "", fmt.Errorf("error recreating the missing symlinks: %v", err)
+				}
+				lower = newpath
+			} else if lower == "" {
 				return "", fmt.Errorf("Can't stat lower layer %q: %v", newpath, err)
 			}
 		} else {