Support private registry in oras (#102)

Signed-off-by: Tejaswini Duggaraju <naduggar@microsoft.com>

go.mod

@@ -17,5 +17,5 @@ require (
 	github.com/sirupsen/logrus v1.8.1
 	github.com/spf13/cobra v1.2.1
 	github.com/xlab/treeprint v1.1.0
-	oras.land/oras-go v0.5.1-0.20211118233813-9ec21342ac6c
+	oras.land/oras-go v0.5.1-0.20211129233629-3b1e924da9d7
 )

go.sum

@@ -2530,8 +2530,8 @@ mvdan.cc/lint v0.0.0-20170908181259-adc824a0674b/go.mod h1:2odslEg/xrtNQqCYg2/jC
 mvdan.cc/unparam v0.0.0-20210104141923-aac4ce9116a7/go.mod h1:hBpJkZE8H/sb+VRFvw2+rBpHNsTBcvSpk61hr8mzXZE=
 nhooyr.io/websocket v1.8.6/go.mod h1:B70DZP8IakI65RVQ51MsWP/8jndNma26DVA/nFSCgW0=
 nhooyr.io/websocket v1.8.7/go.mod h1:B70DZP8IakI65RVQ51MsWP/8jndNma26DVA/nFSCgW0=
-oras.land/oras-go v0.5.1-0.20211118233813-9ec21342ac6c h1:ahEyjNEVBRqxTZglDwnUgapWmeHCZe4kDOQwN6epf6g=
-oras.land/oras-go v0.5.1-0.20211118233813-9ec21342ac6c/go.mod h1:s/Q8+g2H7MHrEImZfquIA+RpBdV7fb4CQDff10i/DQ4=
+oras.land/oras-go v0.5.1-0.20211129233629-3b1e924da9d7 h1:iCxH9uBANXN6z4OLwblnrOabOtcUnc3ylv5TpXhQ/ts=
+oras.land/oras-go v0.5.1-0.20211129233629-3b1e924da9d7/go.mod h1:s/Q8+g2H7MHrEImZfquIA+RpBdV7fb4CQDff10i/DQ4=
 pack.ag/amqp v0.11.2/go.mod h1:4/cbmt4EJXSKlG6LCfWHoqmN0uFdy5i/+YFz+fTfhV4=
 rsc.io/binaryregexp v0.2.0/go.mod h1:qTv7/COck+e2FymRvadv62gMdZztPaShugOCi3I+8D8=
 rsc.io/quote/v3 v3.1.0/go.mod h1:yEA65RcK8LyAZtP9Kv3t0HmxON59tX3rD+tICJqUlj0=

pkg/referrerstore/oras/oras.go

@@ -20,8 +20,6 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"github.com/google/go-containerregistry/pkg/name"
-	"github.com/google/go-containerregistry/pkg/v1/remote"
 	oci "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras-go/pkg/content"
 	"oras.land/oras-go/pkg/oras"
@@ -105,12 +103,13 @@ func (store *orasStore) ListReferrers(ctx context.Context, subjectReference comm
 		return referrerstore.ListReferrersResult{}, err
 	}
 
+	ref := fmt.Sprintf("%s@%s", subjectReference.Path, subjectReference.Digest)
 	var referrerDescriptors []artifactspec.Descriptor
 	if artifactTypes == nil {
 		artifactTypes = []string{""}
 	}
 	for _, artifactType := range artifactTypes {
-		_, res, err := oras.Discover(ctx, registryClient.Resolver, subjectReference.Original, artifactType)
+		_, res, err := oras.Discover(ctx, registryClient.Resolver, ref, artifactType)
 		if err != nil {
 			return referrerstore.ListReferrersResult{}, err
 		}
@@ -177,26 +176,14 @@ func (store *orasStore) GetReferenceManifest(ctx context.Context, subjectReferen
 }
 
 func (store *orasStore) GetSubjectDescriptor(ctx context.Context, subjectReference common.Reference) (*ocispecs.SubjectDescriptor, error) {
-	ref, err := name.ParseReference(subjectReference.Original)
+	registryClient, err := store.createRegistryClient(subjectReference)
 	if err != nil {
 		return nil, err
 	}
-	dig, err := remote.Head(ref)
+	_, desc, err := registryClient.Resolve(ctx, subjectReference.Original)
 	if err != nil {
 		return nil, err
 	}
-
-	dg, err := digest.Parse(dig.Digest.String())
-	if err != nil {
-		return nil, err
-	}
-
-	desc := oci.Descriptor{
-		MediaType: string(dig.MediaType),
-		Digest:    dg,
-		Size:      dig.Size,
-		URLs:      dig.URLs,
-	}
 	return &ocispecs.SubjectDescriptor{Descriptor: desc}, nil
 }