layer

pkg/v1/layout/write.go

@@ -318,6 +318,23 @@ func (l Path) RemoveBlob(hash v1.Hash) error {
 	return nil
 }
 
+// BlobExists checks a blob exists at blobs/{hash.Algorithm}/{hash.Hex}
+func (l Path) BlobExists(hash v1.Hash) bool {
+	dir := l.path("blobs", hash.Algorithm)
+	_, err := os.Stat(dir)
+	return !errors.Is(err, os.ErrNotExist)
+}
+
+// BlobExists checks a blob exists at blobs/{hash.Algorithm}/{hash.Hex}
+func (l Path) BlobSize(hash v1.Hash) (int64, error) {
+	dir := l.path("blobs", hash.Algorithm)
+	stat, err := os.Stat(dir)
+	if err != nil {
+		return 0, err
+	}
+	return stat.Size(), nil
+}
+
 // WriteImage writes an image, including its manifest, config and all of its
 // layers, to the blobs directory. If any blob already exists, as determined by
 // the hash filename, does not write it.

pkg/v1/local/layer.go

@@ -0,0 +1,44 @@
+package local
+
+import (
+	"io"
+
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/layout"
+	"github.com/google/go-containerregistry/pkg/v1/partial"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+// remoteImagelayer implements partial.CompressedLayer
+type localLayer struct {
+	path   layout.Path
+	digest v1.Hash
+}
+
+// Compressed implements partial.CompressedLayer.
+func (lp *localLayer) Compressed() (io.ReadCloser, error) {
+	return lp.path.Blob(lp.digest)
+}
+
+// Digest implements partial.CompressedLayer.
+func (lp *localLayer) Digest() (v1.Hash, error) {
+	return lp.digest, nil
+}
+
+// MediaType implements partial.CompressedLayer.
+func (*localLayer) MediaType() (types.MediaType, error) {
+	// TODO
+	return types.DockerLayer, nil
+}
+
+// Size implements partial.CompressedLayer.
+func (rl *localLayer) Size() (int64, error) {
+	return rl.path.BlobSize(rl.digest)
+}
+
+// See partial.Exists.
+func (rl *localLayer) Exists() (bool, error) {
+	return rl.path.BlobExists(rl.digest), nil
+}
+
+var _ partial.CompressedLayer = (*localLayer)(nil)

pkg/v1/local/puller.go

@@ -3,49 +3,103 @@ package local
 import (
 	"context"
 	"errors"
+	"fmt"
 
 	"github.com/google/go-containerregistry/pkg/name"
 	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/layout"
 	"github.com/google/go-containerregistry/pkg/v1/partial"
 	"github.com/google/go-containerregistry/pkg/v1/remote"
+	specsv1 "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 type puller struct {
+	path layout.Path
+}
+
+func NewLocalPuller(path layout.Path) remote.Puller {
+	return &puller{
+		path,
+	}
 }
 
 var _ remote.Puller = (*puller)(nil)
 
 // Artifact implements remote.Puller.
-func (*puller) Artifact(ctx context.Context, ref name.Reference) (partial.Artifact, error) {
-	panic("unimplemented")
+func (p *puller) getDescriptor(ctx context.Context, ref name.Reference) (*v1.Descriptor, error) {
+	idx, err := p.path.ImageIndex()
+	if err != nil {
+		return nil, err
+	}
+	im, err := idx.IndexManifest()
+	if err != nil {
+		return nil, err
+	}
+	for _, manifest := range im.Manifests {
+		if rref, ok := manifest.Annotations[specsv1.AnnotationRefName]; ok {
+			if ref.String() == rref {
+				return &manifest, nil
+			}
+		}
+	}
+	return nil, fmt.Errorf("unknown image: %s", ref.String())
 }
 
-// Get implements remote.Puller.
-func (*puller) Get(ctx context.Context, ref name.Reference) (*remote.Descriptor, error) {
-	panic("unimplemented")
+// Artifact implements remote.Puller.
+func (p *puller) Artifact(ctx context.Context, ref name.Reference) (partial.Artifact, error) {
+	desc, err := p.getDescriptor(ctx, ref)
+	if err != nil {
+		return nil, err
+	}
+	if desc.MediaType.IsImage() {
+		return p.path.Image(desc.Digest)
+	} else if desc.MediaType.IsIndex() {
+		reg, err := p.path.ImageIndex()
+		if err != nil {
+			return nil, err
+		}
+		return reg.ImageIndex(desc.Digest)
+	}
+	return nil, errors.ErrUnsupported
 }
 
 // Head implements remote.Puller.
-func (*puller) Head(ctx context.Context, ref name.Reference) (*v1.Descriptor, error) {
-	panic("unimplemented")
+func (p *puller) Head(ctx context.Context, ref name.Reference) (*v1.Descriptor, error) {
+	return p.getDescriptor(ctx, ref)
 }
 
 // Layer implements remote.Puller.
-func (*puller) Layer(ctx context.Context, ref name.Digest) (v1.Layer, error) {
-	panic("unimplemented")
+func (p *puller) Layer(ctx context.Context, ref name.Digest) (v1.Layer, error) {
+	h, err := v1.NewHash(ref.Identifier())
+	if err != nil {
+		return nil, err
+	}
+	l, err := partial.CompressedToLayer(&localLayer{
+		path:   p.path,
+		digest: h,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return l, nil
 }
 
 // List implements remote.Puller.
 func (*puller) List(ctx context.Context, repo name.Repository) ([]string, error) {
-	return nil, errors.New("unimplemented")
+	return nil, errors.ErrUnsupported
+}
+
+// Get implements remote.Puller.
+func (*puller) Get(ctx context.Context, ref name.Reference) (*remote.Descriptor, error) {
+	return nil, errors.ErrUnsupported
 }
 
 // Lister implements remote.Puller.
 func (*puller) Lister(ctx context.Context, repo name.Repository) (*remote.Lister, error) {
-	return nil, errors.New("unimplemented")
+	return nil, errors.ErrUnsupported
 }
 
 // Catalogger implements remote.Puller.
 func (*puller) Catalogger(ctx context.Context, reg name.Registry) (*remote.Catalogger, error) {
-	return nil, errors.New("unimplemented")
+	return nil, errors.ErrUnsupported
 }