Unify docker and oci importer

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

images/oci/importer.go

@@ -1,127 +0,0 @@
-/*
-   Copyright The containerd Authors.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-// Package oci provides the importer and the exporter for OCI Image Spec.
-package oci
-
-import (
-	"archive/tar"
-	"bytes"
-	"context"
-	"io"
-	"io/ioutil"
-	"path"
-	"strings"
-
-	"github.com/containerd/containerd/content"
-	"github.com/containerd/containerd/images"
-	"github.com/containerd/containerd/log"
-	digest "github.com/opencontainers/go-digest"
-	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
-	"github.com/pkg/errors"
-)
-
-// V1Importer implements OCI Image Spec v1.
-type V1Importer struct{}
-
-var _ images.Importer = &V1Importer{}
-
-// Import implements Importer.
-func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io.Reader) (ocispec.Descriptor, error) {
-	var (
-		desc ocispec.Descriptor
-		tr   = tar.NewReader(reader)
-	)
-	for {
-		hdr, err := tr.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return ocispec.Descriptor{}, err
-		}
-		if hdr.Typeflag != tar.TypeReg && hdr.Typeflag != tar.TypeRegA {
-			log.G(ctx).WithField("file", hdr.Name).Debug("file type ignored")
-			continue
-		}
-		hdrName := path.Clean(hdr.Name)
-		if hdrName == "index.json" {
-			if desc.Digest != "" {
-				return ocispec.Descriptor{}, errors.New("duplicated index.json")
-			}
-			desc, err = onUntarIndexJSON(ctx, tr, store, hdr.Size)
-			if err != nil {
-				return ocispec.Descriptor{}, err
-			}
-		} else if strings.HasPrefix(hdrName, "blobs/") {
-			if err := onUntarBlob(ctx, tr, store, hdrName, hdr.Size); err != nil {
-				return ocispec.Descriptor{}, err
-			}
-		} else if hdrName == ocispec.ImageLayoutFile {
-			// TODO Validate
-		} else {
-			log.G(ctx).WithField("file", hdr.Name).Debug("unknown file ignored")
-		}
-	}
-	if desc.Digest == "" {
-		return ocispec.Descriptor{}, errors.New("no index.json found")
-	}
-
-	return desc, nil
-}
-
-func onUntarIndexJSON(ctx context.Context, r io.Reader, store content.Ingester, size int64) (ocispec.Descriptor, error) {
-	b, err := ioutil.ReadAll(r)
-	if err != nil {
-		return ocispec.Descriptor{}, err
-	}
-	desc := ocispec.Descriptor{
-		MediaType: ocispec.MediaTypeImageIndex,
-		Digest:    digest.FromBytes(b),
-		Size:      size,
-	}
-	if int64(len(b)) != size {
-		return ocispec.Descriptor{}, errors.Errorf("size mismatch %d v %d", len(b), size)
-	}
-
-	if err := content.WriteBlob(ctx, store, "index-"+desc.Digest.String(), bytes.NewReader(b), desc); err != nil {
-		return ocispec.Descriptor{}, err
-	}
-
-	return desc, err
-}
-
-func onUntarBlob(ctx context.Context, r io.Reader, store content.Ingester, name string, size int64) error {
-	// name is like "blobs/sha256/deadbeef"
-	split := strings.Split(name, "/")
-	if len(split) != 3 {
-		return errors.Errorf("unexpected name: %q", name)
-	}
-	algo := digest.Algorithm(split[1])
-	if !algo.Available() {
-		return errors.Errorf("unsupported algorithm: %s", algo)
-	}
-	dgst := digest.NewDigestFromHex(algo.String(), split[2])
-	return content.WriteBlob(ctx, store, "blob-"+dgst.String(), r, ocispec.Descriptor{Size: size, Digest: dgst})
-}
-
-// DigestTranslator creates a digest reference by adding the
-// digest to an image name
-func DigestTranslator(prefix string) func(digest.Digest) string {
-	return func(dgst digest.Digest) string {
-		return prefix + "@" + dgst.String()
-	}
-}