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Unify docker and oci importer

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Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This commit is contained in:
Derek McGowan
2018-09-12 16:58:22 -07:00
parent bce20b75da
commit a62be324b7
7 changed files with 64 additions and 203 deletions
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42
images/docker/importer.go → images/archive/importer.go
View File

@@ -14,9 +14,8 @@
limitations under the License.
*/
// Package docker provides a Docker compatible importer capable of
// importing both Docker and OCI formats.
package docker
// Package archive provides a Docker and OCI compatible importer
package archive
import (
"archive/tar"
@@ -37,19 +36,15 @@ import (
"github.com/pkg/errors"
)
// V1Importer implements Docker v1.1, v1.2 and OCI v1.
type V1Importer struct {
// SkipOCI prevent interpretting OCI files
SkipOCI bool
// TODO: Add option to compress layers on ingest
}
var _ images.Importer = &V1Importer{}
// Import implements Importer.
func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io.Reader) (ocispec.Descriptor, error) {
// ImportIndex imports an index from a tar achive image bundle
// - implements Docker v1.1, v1.2 and OCI v1.
// - prefers OCI v1 when provided
// - creates OCI index for Docker formats
// - normalizes Docker references and adds as OCI ref name
// e.g. alpine:latest -> docker.io/library/alpine:latest
// - existing OCI reference names are untouched
// - TODO: support option to compress layers on ingest
func ImportIndex(ctx context.Context, store content.Store, reader io.Reader) (ocispec.Descriptor, error) {
var (
tr = tar.NewReader(reader)
@@ -82,7 +77,7 @@ func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io
}
hdrName := path.Clean(hdr.Name)
if hdrName == ocispec.ImageLayoutFile && !oi.SkipOCI {
if hdrName == ocispec.ImageLayoutFile {
if err = onUntarJSON(tr, &ociLayout); err != nil {
return ocispec.Descriptor{}, errors.Wrapf(err, "untar oci layout %q", hdr.Name)
}
@@ -103,6 +98,9 @@ func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io
}
}
// If OCI layout was given, interpret the tar as an OCI layout.
// When not provided, the layout of the tar will be interpretted
// as Docker v1.1 or v1.2.
if ociLayout.Version != "" {
if ociLayout.Version != ocispec.ImageLayoutVersion {
return ocispec.Descriptor{}, errors.Errorf("unsupported OCI version %s", ociLayout.Version)
@@ -156,7 +154,9 @@ func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io
return ocispec.Descriptor{}, errors.Wrap(err, "unable to resolve platform")
}
if len(platforms) > 0 {
// Only one platform can be resolved from non-index manifest
// Only one platform can be resolved from non-index manifest,
// The platform can only come from the config included above,
// if the config has no platform it can be safely ommitted.
desc.Platform = &platforms[0]
}
@@ -165,18 +165,18 @@ func (oi *V1Importer) Import(ctx context.Context, store content.Store, reader io
} else {
// Add descriptor per tag
for _, ref := range mfst.RepoTags {
msftdesc := desc
mfstdesc := desc
normalized, err := normalizeReference(ref)
if err != nil {
return ocispec.Descriptor{}, err
}
msftdesc.Annotations = map[string]string{
mfstdesc.Annotations = map[string]string{
ocispec.AnnotationRefName: normalized,
}
idx.Manifests = append(idx.Manifests, msftdesc)
idx.Manifests = append(idx.Manifests, mfstdesc)
}
}
}

27
images/docker/reference.go → images/archive/reference.go
View File

@@ -14,18 +14,31 @@
limitations under the License.
*/
package docker
package archive
import (
"strings"
"github.com/containerd/cri/pkg/util"
digest "github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
// RefTranslator creates a reference which only has a tag or verifies
// FilterRefPrefix restricts references to having the given image
// prefix. Tag-only references will have the prefix prepended.
func FilterRefPrefix(image string) func(string) string {
return refTranslator(image, true)
}
// AddRefPrefix prepends the given image prefix to tag-only references,
// while leaving returning full references unmodified.
func AddRefPrefix(image string) func(string) string {
return refTranslator(image, false)
}
// refTranslator creates a reference which only has a tag or verifies
// a full reference.
func RefTranslator(image string, checkPrefix bool) func(string) string {
func refTranslator(image string, checkPrefix bool) func(string) string {
return func(ref string) string {
// Check if ref is full reference
if strings.ContainsAny(ref, "/:@") {
@@ -63,3 +76,11 @@ func normalizeReference(ref string) (string, error) {
return normalized.String(), nil
}
// 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()
}
}

127
images/oci/importer.go
View File

@@ -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()
}
}