Add storage.Transport.NewStoreReference

To allow callers to create storage reference without having to
parse strings.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

storage/storage_reference.go

@@ -30,6 +30,14 @@ func newReference(transport storageTransport, named reference.Named, id string)
 	if named == nil && id == "" {
 		return nil, ErrInvalidReference
 	}
+	if named != nil && reference.IsNameOnly(named) {
+		return nil, errors.Wrapf(ErrInvalidReference, "reference %s has neither a tag nor a digest", named.String())
+	}
+	if id != "" {
+		if err := validateImageID(id); err != nil {
+			return nil, errors.Wrapf(ErrInvalidReference, "invalid ID value %q: %v", id, err)
+		}
+	}
 	// We take a copy of the transport, which contains a pointer to the
 	// store that it used for resolving this reference, so that the
 	// transport that we'll return from Transport() won't be affected by

storage/storage_reference_test.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/containers/image/v5/docker/reference"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -18,6 +19,12 @@ func TestNewReference(t *testing.T) {
 	// Success is tested throughout; test only the failure
 	_, err := newReference(*st, nil, "")
 	assert.Error(t, err)
+	_, err = newReference(*st, nil, "ab")
+	assert.Error(t, err)
+	ref, err := reference.ParseNormalizedNamed("busybox")
+	require.NoError(t, err)
+	_, err = newReference(*st, ref, "")
+	assert.Error(t, err)
 }
 
 func TestStorageReferenceTransport(t *testing.T) {

storage/storage_transport.go

@@ -54,6 +54,9 @@ type StoreTransport interface {
 	// ParseStoreReference parses a reference, overriding any store
 	// specification that it may contain.
 	ParseStoreReference(store storage.Store, reference string) (*storageReference, error)
+	// NewStoreReference creates a reference for (named@ID) in store.
+	// either of name or ID can be unset; named must not be a reference.IsNameOnly.
+	NewStoreReference(store storage.Store, named reference.Named, id string) (*storageReference, error)
 	// SetDefaultUIDMap sets the default UID map to use when opening stores.
 	SetDefaultUIDMap(idmap []idtools.IDMap)
 	// SetDefaultGIDMap sets the default GID map to use when opening stores.
@@ -174,14 +177,20 @@ func (s storageTransport) ParseStoreReference(store storage.Store, ref string) (
 		named = reference.TagNameOnly(named)
 	}
 
-	result, err := newReference(storageTransport{store: store, defaultUIDMap: s.defaultUIDMap, defaultGIDMap: s.defaultGIDMap}, named, id)
+	result, err := s.NewStoreReference(store, named, id)
 	if err != nil {
 		return nil, err
 	}
 	logrus.Debugf("parsed reference into %q", result.StringWithinTransport())
 	return result, nil
 }
 
+// NewStoreReference creates a reference for (named@ID) in store.
+// either of name or ID can be unset; named must not be a reference.IsNameOnly.
+func (s *storageTransport) NewStoreReference(store storage.Store, named reference.Named, id string) (*storageReference, error) {
+	return newReference(storageTransport{store: store, defaultUIDMap: s.defaultUIDMap, defaultGIDMap: s.defaultGIDMap}, named, id)
+}
+
 func (s *storageTransport) GetStore() (storage.Store, error) {
 	// Return the transport's previously-set store.  If we don't have one
 	// of those, initialize one now.