distribution/registry/proxy/proxytagservice.go
Richard Scothern 56af60ad24 To avoid any network use unless necessary, delay establishing authorization
challenges with the upstream until any proxied data is found not to be local.

Implement auth challenges behind an interface and add to unit tests.  Also,
remove a non-sensical unit test.

Signed-off-by: Richard Scothern <richard.scothern@docker.com>
2016-02-16 11:53:42 -08:00

65 lines
1.7 KiB
Go

package proxy
import (
"github.com/docker/distribution"
"github.com/docker/distribution/context"
)
// proxyTagService supports local and remote lookup of tags.
type proxyTagService struct {
localTags distribution.TagService
remoteTags distribution.TagService
authChallenger authChallenger
}
var _ distribution.TagService = proxyTagService{}
// Get attempts to get the most recent digest for the tag by checking the remote
// tag service first and then caching it locally. If the remote is unavailable
// the local association is returned
func (pt proxyTagService) Get(ctx context.Context, tag string) (distribution.Descriptor, error) {
err := pt.authChallenger.tryEstablishChallenges(ctx)
if err == nil {
desc, err := pt.remoteTags.Get(ctx, tag)
if err == nil {
err := pt.localTags.Tag(ctx, tag, desc)
if err != nil {
return distribution.Descriptor{}, err
}
return desc, nil
}
}
desc, err := pt.localTags.Get(ctx, tag)
if err != nil {
return distribution.Descriptor{}, err
}
return desc, nil
}
func (pt proxyTagService) Tag(ctx context.Context, tag string, desc distribution.Descriptor) error {
return distribution.ErrUnsupported
}
func (pt proxyTagService) Untag(ctx context.Context, tag string) error {
err := pt.localTags.Untag(ctx, tag)
if err != nil {
return err
}
return nil
}
func (pt proxyTagService) All(ctx context.Context) ([]string, error) {
err := pt.authChallenger.tryEstablishChallenges(ctx)
if err == nil {
tags, err := pt.remoteTags.All(ctx)
if err == nil {
return tags, err
}
}
return pt.localTags.All(ctx)
}
func (pt proxyTagService) Lookup(ctx context.Context, digest distribution.Descriptor) ([]string, error) {
return []string{}, distribution.ErrUnsupported
}