Bump github.com/containers/image@efae299

Update the vendored copy of github.com/containers/image to revision
efae29995d4846ffa6163eb4d466fd61bda43aae.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

vendor/github.com/containers/image/docker/daemon/daemon_src.go

@@ -1,19 +1,13 @@
 package daemon
 
 import (
-	"archive/tar"
-	"bytes"
-	"encoding/json"
 	"io"
 	"io/ioutil"
 	"os"
-	"path"
 
-	"github.com/containers/image/manifest"
-	"github.com/containers/image/pkg/compression"
+	"github.com/containers/image/docker/tarfile"
 	"github.com/containers/image/types"
 	"github.com/docker/docker/client"
-	"github.com/opencontainers/go-digest"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 )
@@ -21,16 +15,9 @@ import (
 const temporaryDirectoryForBigFiles = "/var/tmp" // Do not use the system default of os.TempDir(), usually /tmp, because with systemd it could be a tmpfs.
 
 type daemonImageSource struct {
-	ref         daemonReference
-	tarCopyPath string
-	// The following data is only available after ensureCachedDataIsPresent() succeeds
-	tarManifest       *manifestItem // nil if not available yet.
-	configBytes       []byte
-	configDigest      digest.Digest
-	orderedDiffIDList []diffID
-	knownLayers       map[diffID]*layerInfo
-	// Other state
-	generatedManifest []byte // Private cache for GetManifest(), nil if not set yet.
+	ref             daemonReference
+	*tarfile.Source // Implements most of types.ImageSource
+	tarCopyPath     string
 }
 
 type layerInfo struct {
@@ -81,6 +68,7 @@ func newImageSource(ctx *types.SystemContext, ref daemonReference) (types.ImageS
 	succeeded = true
 	return &daemonImageSource{
 		ref:         ref,
+		Source:      tarfile.NewSource(tarCopyFile.Name()),
 		tarCopyPath: tarCopyFile.Name(),
 	}, nil
 }
@@ -95,310 +83,3 @@ func (s *daemonImageSource) Reference() types.ImageReference {
 func (s *daemonImageSource) Close() error {
 	return os.Remove(s.tarCopyPath)
 }
-
-// tarReadCloser is a way to close the backing file of a tar.Reader when the user no longer needs the tar component.
-type tarReadCloser struct {
-	*tar.Reader
-	backingFile *os.File
-}
-
-func (t *tarReadCloser) Close() error {
-	return t.backingFile.Close()
-}
-
-// openTarComponent returns a ReadCloser for the specific file within the archive.
-// This is linear scan; we assume that the tar file will have a fairly small amount of files (~layers),
-// and that filesystem caching will make the repeated seeking over the (uncompressed) tarCopyPath cheap enough.
-// The caller should call .Close() on the returned stream.
-func (s *daemonImageSource) openTarComponent(componentPath string) (io.ReadCloser, error) {
-	f, err := os.Open(s.tarCopyPath)
-	if err != nil {
-		return nil, err
-	}
-	succeeded := false
-	defer func() {
-		if !succeeded {
-			f.Close()
-		}
-	}()
-
-	tarReader, header, err := findTarComponent(f, componentPath)
-	if err != nil {
-		return nil, err
-	}
-	if header == nil {
-		return nil, os.ErrNotExist
-	}
-	if header.FileInfo().Mode()&os.ModeType == os.ModeSymlink { // FIXME: untested
-		// We follow only one symlink; so no loops are possible.
-		if _, err := f.Seek(0, os.SEEK_SET); err != nil {
-			return nil, err
-		}
-		// The new path could easily point "outside" the archive, but we only compare it to existing tar headers without extracting the archive,
-		// so we don't care.
-		tarReader, header, err = findTarComponent(f, path.Join(path.Dir(componentPath), header.Linkname))
-		if err != nil {
-			return nil, err
-		}
-		if header == nil {
-			return nil, os.ErrNotExist
-		}
-	}
-
-	if !header.FileInfo().Mode().IsRegular() {
-		return nil, errors.Errorf("Error reading tar archive component %s: not a regular file", header.Name)
-	}
-	succeeded = true
-	return &tarReadCloser{Reader: tarReader, backingFile: f}, nil
-}
-
-// findTarComponent returns a header and a reader matching path within inputFile,
-// or (nil, nil, nil) if not found.
-func findTarComponent(inputFile io.Reader, path string) (*tar.Reader, *tar.Header, error) {
-	t := tar.NewReader(inputFile)
-	for {
-		h, err := t.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return nil, nil, err
-		}
-		if h.Name == path {
-			return t, h, nil
-		}
-	}
-	return nil, nil, nil
-}
-
-// readTarComponent returns full contents of componentPath.
-func (s *daemonImageSource) readTarComponent(path string) ([]byte, error) {
-	file, err := s.openTarComponent(path)
-	if err != nil {
-		return nil, errors.Wrapf(err, "Error loading tar component %s", path)
-	}
-	defer file.Close()
-	bytes, err := ioutil.ReadAll(file)
-	if err != nil {
-		return nil, err
-	}
-	return bytes, nil
-}
-
-// ensureCachedDataIsPresent loads data necessary for any of the public accessors.
-func (s *daemonImageSource) ensureCachedDataIsPresent() error {
-	if s.tarManifest != nil {
-		return nil
-	}
-
-	// Read and parse manifest.json
-	tarManifest, err := s.loadTarManifest()
-	if err != nil {
-		return err
-	}
-
-	// Read and parse config.
-	configBytes, err := s.readTarComponent(tarManifest.Config)
-	if err != nil {
-		return err
-	}
-	var parsedConfig dockerImage // Most fields ommitted, we only care about layer DiffIDs.
-	if err := json.Unmarshal(configBytes, &parsedConfig); err != nil {
-		return errors.Wrapf(err, "Error decoding tar config %s", tarManifest.Config)
-	}
-
-	knownLayers, err := s.prepareLayerData(tarManifest, &parsedConfig)
-	if err != nil {
-		return err
-	}
-
-	// Success; commit.
-	s.tarManifest = tarManifest
-	s.configBytes = configBytes
-	s.configDigest = digest.FromBytes(configBytes)
-	s.orderedDiffIDList = parsedConfig.RootFS.DiffIDs
-	s.knownLayers = knownLayers
-	return nil
-}
-
-// loadTarManifest loads and decodes the manifest.json.
-func (s *daemonImageSource) loadTarManifest() (*manifestItem, error) {
-	// FIXME? Do we need to deal with the legacy format?
-	bytes, err := s.readTarComponent(manifestFileName)
-	if err != nil {
-		return nil, err
-	}
-	var items []manifestItem
-	if err := json.Unmarshal(bytes, &items); err != nil {
-		return nil, errors.Wrap(err, "Error decoding tar manifest.json")
-	}
-	if len(items) != 1 {
-		return nil, errors.Errorf("Unexpected tar manifest.json: expected 1 item, got %d", len(items))
-	}
-	return &items[0], nil
-}
-
-func (s *daemonImageSource) prepareLayerData(tarManifest *manifestItem, parsedConfig *dockerImage) (map[diffID]*layerInfo, error) {
-	// Collect layer data available in manifest and config.
-	if len(tarManifest.Layers) != len(parsedConfig.RootFS.DiffIDs) {
-		return nil, errors.Errorf("Inconsistent layer count: %d in manifest, %d in config", len(tarManifest.Layers), len(parsedConfig.RootFS.DiffIDs))
-	}
-	knownLayers := map[diffID]*layerInfo{}
-	unknownLayerSizes := map[string]*layerInfo{} // Points into knownLayers, a "to do list" of items with unknown sizes.
-	for i, diffID := range parsedConfig.RootFS.DiffIDs {
-		if _, ok := knownLayers[diffID]; ok {
-			// Apparently it really can happen that a single image contains the same layer diff more than once.
-			// In that case, the diffID validation ensures that both layers truly are the same, and it should not matter
-			// which of the tarManifest.Layers paths is used; (docker save) actually makes the duplicates symlinks to the original.
-			continue
-		}
-		layerPath := tarManifest.Layers[i]
-		if _, ok := unknownLayerSizes[layerPath]; ok {
-			return nil, errors.Errorf("Layer tarfile %s used for two different DiffID values", layerPath)
-		}
-		li := &layerInfo{ // A new element in each iteration
-			path: layerPath,
-			size: -1,
-		}
-		knownLayers[diffID] = li
-		unknownLayerSizes[layerPath] = li
-	}
-
-	// Scan the tar file to collect layer sizes.
-	file, err := os.Open(s.tarCopyPath)
-	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-	t := tar.NewReader(file)
-	for {
-		h, err := t.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return nil, err
-		}
-		if li, ok := unknownLayerSizes[h.Name]; ok {
-			li.size = h.Size
-			delete(unknownLayerSizes, h.Name)
-		}
-	}
-	if len(unknownLayerSizes) != 0 {
-		return nil, errors.Errorf("Some layer tarfiles are missing in the tarball") // This could do with a better error reporting, if this ever happened in practice.
-	}
-
-	return knownLayers, nil
-}
-
-// GetManifest returns the image's manifest along with its MIME type (which may be empty when it can't be determined but the manifest is available).
-// It may use a remote (= slow) service.
-func (s *daemonImageSource) GetManifest() ([]byte, string, error) {
-	if s.generatedManifest == nil {
-		if err := s.ensureCachedDataIsPresent(); err != nil {
-			return nil, "", err
-		}
-		m := schema2Manifest{
-			SchemaVersion: 2,
-			MediaType:     manifest.DockerV2Schema2MediaType,
-			Config: distributionDescriptor{
-				MediaType: manifest.DockerV2Schema2ConfigMediaType,
-				Size:      int64(len(s.configBytes)),
-				Digest:    s.configDigest,
-			},
-			Layers: []distributionDescriptor{},
-		}
-		for _, diffID := range s.orderedDiffIDList {
-			li, ok := s.knownLayers[diffID]
-			if !ok {
-				return nil, "", errors.Errorf("Internal inconsistency: Information about layer %s missing", diffID)
-			}
-			m.Layers = append(m.Layers, distributionDescriptor{
-				Digest:    digest.Digest(diffID), // diffID is a digest of the uncompressed tarball
-				MediaType: manifest.DockerV2Schema2LayerMediaType,
-				Size:      li.size,
-			})
-		}
-		manifestBytes, err := json.Marshal(&m)
-		if err != nil {
-			return nil, "", err
-		}
-		s.generatedManifest = manifestBytes
-	}
-	return s.generatedManifest, manifest.DockerV2Schema2MediaType, nil
-}
-
-// GetTargetManifest returns an image's manifest given a digest. This is mainly used to retrieve a single image's manifest
-// out of a manifest list.
-func (s *daemonImageSource) GetTargetManifest(digest digest.Digest) ([]byte, string, error) {
-	// How did we even get here? GetManifest() above has returned a manifest.DockerV2Schema2MediaType.
-	return nil, "", errors.Errorf(`Manifest lists are not supported by "docker-daemon:"`)
-}
-
-type readCloseWrapper struct {
-	io.Reader
-	closeFunc func() error
-}
-
-func (r readCloseWrapper) Close() error {
-	if r.closeFunc != nil {
-		return r.closeFunc()
-	}
-	return nil
-}
-
-// GetBlob returns a stream for the specified blob, and the blob’s size (or -1 if unknown).
-func (s *daemonImageSource) GetBlob(info types.BlobInfo) (io.ReadCloser, int64, error) {
-	if err := s.ensureCachedDataIsPresent(); err != nil {
-		return nil, 0, err
-	}
-
-	if info.Digest == s.configDigest { // FIXME? Implement a more general algorithm matching instead of assuming sha256.
-		return ioutil.NopCloser(bytes.NewReader(s.configBytes)), int64(len(s.configBytes)), nil
-	}
-
-	if li, ok := s.knownLayers[diffID(info.Digest)]; ok { // diffID is a digest of the uncompressed tarball,
-		stream, err := s.openTarComponent(li.path)
-		if err != nil {
-			return nil, 0, err
-		}
-
-		// In order to handle the fact that digests != diffIDs (and thus that a
-		// caller which is trying to verify the blob will run into problems),
-		// we need to decompress blobs. This is a bit ugly, but it's a
-		// consequence of making everything addressable by their DiffID rather
-		// than by their digest...
-		//
-		// In particular, because the v2s2 manifest being generated uses
-		// DiffIDs, any caller of GetBlob is going to be asking for DiffIDs of
-		// layers not their _actual_ digest. The result is that copy/... will
-		// be verifing a "digest" which is not the actual layer's digest (but
-		// is instead the DiffID).
-
-		decompressFunc, reader, err := compression.DetectCompression(stream)
-		if err != nil {
-			return nil, 0, errors.Wrapf(err, "Detecting compression in blob %s", info.Digest)
-		}
-
-		if decompressFunc != nil {
-			reader, err = decompressFunc(reader)
-			if err != nil {
-				return nil, 0, errors.Wrapf(err, "Decompressing blob %s stream", info.Digest)
-			}
-		}
-
-		newStream := readCloseWrapper{
-			Reader:    reader,
-			closeFunc: stream.Close,
-		}
-
-		return newStream, li.size, nil
-	}
-
-	return nil, 0, errors.Errorf("Unknown blob %s", info.Digest)
-}
-
-// GetSignatures returns the image's signatures.  It may use a remote (= slow) service.
-func (s *daemonImageSource) GetSignatures() ([][]byte, error) {
-	return [][]byte{}, nil
-}