containerd/remotes/handlers.go
Stephen J Day 39da6ff879
images: move image package to images
Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-03-21 17:36:37 -07:00

66 lines
2.3 KiB
Go

package remotes
import (
"context"
"fmt"
"github.com/Sirupsen/logrus"
"github.com/docker/containerd/content"
"github.com/docker/containerd/images"
"github.com/docker/containerd/log"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
)
// MakeRef returns a unique reference for the descriptor. This reference can be
// used to lookup ongoing processes related to the descriptor. This function
// may look to the context to namespace the reference appropriately.
func MakeRefKey(ctx context.Context, desc ocispec.Descriptor) string {
// TODO(stevvooe): Need better remote key selection here. Should be a
// product of the context, which may include information about the ongoing
// fetch process.
switch desc.MediaType {
case images.MediaTypeDockerSchema2Manifest, ocispec.MediaTypeImageManifest,
images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
return "manifest-" + desc.Digest.String()
case images.MediaTypeDockerSchema2Layer, images.MediaTypeDockerSchema2LayerGzip:
return "layer-" + desc.Digest.String()
case "application/vnd.docker.container.image.v1+json":
return "config-" + desc.Digest.String()
default:
log.G(ctx).Warnf("reference for unknown type: %s", desc.MediaType)
return "unknown-" + desc.Digest.String()
}
}
// FetchHandler returns a handler that will fetch all content into the ingester
// discovered in a call to Dispatch. Use with ChildrenHandler to do a full
// recursive fetch.
func FetchHandler(ingester content.Ingester, fetcher Fetcher) images.HandlerFunc {
return func(ctx context.Context, desc ocispec.Descriptor) (subdescs []ocispec.Descriptor, err error) {
ctx = log.WithLogger(ctx, log.G(ctx).WithFields(logrus.Fields{
"digest": desc.Digest,
"mediatype": desc.MediaType,
"size": desc.Size,
}))
switch desc.MediaType {
case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
return nil, fmt.Errorf("%v not yet supported", desc.MediaType)
default:
err := fetch(ctx, ingester, fetcher, desc)
return nil, err
}
}
}
func fetch(ctx context.Context, ingester content.Ingester, fetcher Fetcher, desc ocispec.Descriptor) error {
log.G(ctx).Debug("fetch")
ref := MakeRefKey(ctx, desc)
rc, err := fetcher.Fetch(ctx, desc)
if err != nil {
return err
}
defer rc.Close()
return content.WriteBlob(ctx, ingester, ref, rc, desc.Size, desc.Digest)
}