Drop our dependency on github.com/containers/image

Drop our dependency on the image library's manifest package by requiring
that callers pass its Digest() function to us as a callback.  This makes
our CLI test/diagnostic tool calculate digests of s1 manifests
incorrectly, but that's not something that we were testing.

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

storage/cmd/containers-storage/image.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/mflag"
+	digest "github.com/opencontainers/go-digest"
 )
 
 var (
@@ -95,6 +96,10 @@ func getImageBigData(flags *mflag.FlagSet, action string, m storage.Store, args
 	return 0
 }
 
+func wrongManifestDigest(b []byte) (digest.Digest, error) {
+	return digest.Canonical.FromBytes(b), nil
+}
+
 func getImageBigDataSize(flags *mflag.FlagSet, action string, m storage.Store, args []string) int {
 	image, err := m.Image(args[0])
 	if err != nil {
@@ -149,7 +154,7 @@ func setImageBigData(flags *mflag.FlagSet, action string, m storage.Store, args
 		fmt.Fprintf(os.Stderr, "%v\n", err)
 		return 1
 	}
-	err = m.SetImageBigData(image.ID, args[1], b)
+	err = m.SetImageBigData(image.ID, args[1], b, wrongManifestDigest)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
 		return 1
@@ -207,7 +212,7 @@ func init() {
 		command{
 			names:       []string{"set-image-data", "setimagedata"},
 			optionsHelp: "[options [...]] imageNameOrID dataName",
-			usage:       "Set data that is attached to an image",
+			usage:       "Set data that is attached to an image (with sometimes wrong digest)",
 			action:      setImageBigData,
 			minArgs:     2,
 			addFlags: func(flags *mflag.FlagSet, cmd *command) {

storage/containers.go

@@ -71,7 +71,7 @@ type Container struct {
 type ContainerStore interface {
 	FileBasedStore
 	MetadataStore
-	BigDataStore
+	ContainerBigDataStore
 	FlaggableStore
 
 	// Create creates a container that has a specified ID (or generates a
@@ -456,7 +456,7 @@ func (r *containerStore) BigDataSize(id, key string) (int64, error) {
 		return size, nil
 	}
 	if data, err := r.BigData(id, key); err == nil && data != nil {
-		if r.SetBigData(id, key, data) == nil {
+		if err = r.SetBigData(id, key, data); err == nil {
 			c, ok := r.lookup(id)
 			if !ok {
 				return -1, ErrContainerUnknown
@@ -464,6 +464,8 @@ func (r *containerStore) BigDataSize(id, key string) (int64, error) {
 			if size, ok := c.BigDataSizes[key]; ok {
 				return size, nil
 			}
+		} else {
+			return -1, err
 		}
 	}
 	return -1, ErrSizeUnknown
@@ -484,7 +486,7 @@ func (r *containerStore) BigDataDigest(id, key string) (digest.Digest, error) {
 		return d, nil
 	}
 	if data, err := r.BigData(id, key); err == nil && data != nil {
-		if r.SetBigData(id, key, data) == nil {
+		if err = r.SetBigData(id, key, data); err == nil {
 			c, ok := r.lookup(id)
 			if !ok {
 				return "", ErrContainerUnknown
@@ -492,6 +494,8 @@ func (r *containerStore) BigDataDigest(id, key string) (digest.Digest, error) {
 			if d, ok := c.BigDataDigests[key]; ok {
 				return d, nil
 			}
+		} else {
+			return "", err
 		}
 	}
 	return "", ErrDigestUnknown

storage/images.go

@@ -8,7 +8,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/containers/image/manifest"
 	"github.com/containers/storage/pkg/ioutils"
 	"github.com/containers/storage/pkg/stringid"
 	"github.com/containers/storage/pkg/truncindex"
@@ -117,7 +116,7 @@ type ImageStore interface {
 	ROImageStore
 	RWFileBasedStore
 	RWMetadataStore
-	RWBigDataStore
+	RWImageBigDataStore
 	FlaggableStore
 
 	// Create creates an image that has a specified ID (or a random one) and
@@ -636,7 +635,7 @@ func imageSliceWithoutValue(slice []*Image, value *Image) []*Image {
 	return modified
 }
 
-func (r *imageStore) SetBigData(id, key string, data []byte) error {
+func (r *imageStore) SetBigData(id, key string, data []byte, digestManifest func([]byte) (digest.Digest, error)) error {
 	if key == "" {
 		return errors.Wrapf(ErrInvalidBigDataName, "can't set empty name for image big data item")
 	}
@@ -653,7 +652,10 @@ func (r *imageStore) SetBigData(id, key string, data []byte) error {
 	}
 	var newDigest digest.Digest
 	if bigDataNameIsManifest(key) {
-		if newDigest, err = manifest.Digest(data); err != nil {
+		if digestManifest == nil {
+			return errors.Wrapf(ErrDigestUnknown, "error digesting manifest: no manifest digest callback provided")
+		}
+		if newDigest, err = digestManifest(data); err != nil {
 			return errors.Wrapf(err, "error digesting manifest")
 		}
 	} else {

storage/store.go

@@ -102,19 +102,21 @@ type ROBigDataStore interface {
 	BigDataNames(id string) ([]string, error)
 }
 
-// A RWBigDataStore wraps up the read-write big-data related methods of the
-// various types of file-based lookaside stores that we implement.
-type RWBigDataStore interface {
-	// SetBigData stores a (potentially large) piece of data associated with this
-	// ID.
-	SetBigData(id, key string, data []byte) error
+// A RWImageBigDataStore wraps up how we store big-data associated with images.
+type RWImageBigDataStore interface {
+	// SetBigData stores a (potentially large) piece of data associated
+	// with this ID.
+	// Pass github.com/containers/image/manifest.Digest as digestManifest
+	// to allow ByDigest to find images by their correct digests.
+	SetBigData(id, key string, data []byte, digestManifest func([]byte) (digest.Digest, error)) error
 }
 
-// A BigDataStore wraps up the most common big-data related methods of the
-// various types of file-based lookaside stores that we implement.
-type BigDataStore interface {
+// A ContainerBigDataStore wraps up how we store big-data associated with containers.
+type ContainerBigDataStore interface {
 	ROBigDataStore
-	RWBigDataStore
+	// SetBigData stores a (potentially large) piece of data associated
+	// with this ID.
+	SetBigData(id, key string, data []byte) error
 }
 
 // A FlaggableStore can have flags set and cleared on items which it manages.
@@ -352,9 +354,11 @@ type Store interface {
 	// of named data associated with an image.
 	ImageBigDataDigest(id, key string) (digest.Digest, error)
 
-	// SetImageBigData stores a (possibly large) chunk of named data associated
-	// with an image.
-	SetImageBigData(id, key string, data []byte) error
+	// SetImageBigData stores a (possibly large) chunk of named data
+	// associated with an image.  Pass
+	// github.com/containers/image/manifest.Digest as digestManifest to
+	// allow ImagesByDigest to find images by their correct digests.
+	SetImageBigData(id, key string, data []byte, digestManifest func([]byte) (digest.Digest, error)) error
 
 	// ImageSize computes the size of the image's layers and ancillary data.
 	ImageSize(id string) (int64, error)
@@ -1485,7 +1489,7 @@ func (s *store) ImageBigData(id, key string) ([]byte, error) {
 	return nil, ErrImageUnknown
 }
 
-func (s *store) SetImageBigData(id, key string, data []byte) error {
+func (s *store) SetImageBigData(id, key string, data []byte, digestManifest func([]byte) (digest.Digest, error)) error {
 	ristore, err := s.ImageStore()
 	if err != nil {
 		return err
@@ -1499,7 +1503,7 @@ func (s *store) SetImageBigData(id, key string, data []byte) error {
 		}
 	}
 
-	return ristore.SetBigData(id, key, data)
+	return ristore.SetBigData(id, key, data, digestManifest)
 }
 
 func (s *store) ImageSize(id string) (int64, error) {

storage/tests/bigdata.bats

@@ -131,6 +131,7 @@ load helpers
 	run storage get-container-data-size $container no-such-item
 	[ "$status" -ne 0 ]
 	run storage --debug=false get-container-data-size $container big-item-1
+	echo "$output"
 	[ "$status" -eq 0 ]
 	[ "$output" -eq 1234 ]
 	run storage --debug=false get-container-data-size $container big-item-2