renamed the createRepository function and fixed digest resolve

api/tech/oras/client.go

@@ -51,26 +51,20 @@ func New(opts ClientOptions) *Client {
 }
 
 func (c *Client) Resolve(ctx context.Context, ref string) (string, ociv1.Descriptor, error) {
-	src, err := c.resolveRef(ref)
+	src, err := c.createRepository(ref)
 	if err != nil {
 		return "", ociv1.Descriptor{}, err
 	}
 
 	// We try to first resolve a manifest.
+	// _Note_: If there is an error like not found, but we know that the digest exists
+	// we can add src.Blobs().Resolve in here. If we do that, note that
+	// for Blobs().Resolve `not found` is actually `invalid checksum digest format`.
+	// Meaning it will throw that error instead of not found.
 	desc, err := src.Resolve(ctx, ref)
 	if err != nil {
 		if strings.Contains(err.Error(), "not found") {
-			// Then we use the blob store to resolve.
-			desc, err := src.Blobs().Resolve(ctx, ref)
-			if err != nil {
-				if strings.Contains(err.Error(), "not found") {
-					return "", ociv1.Descriptor{}, errdefs.ErrNotFound
-				}
-
-				return "", ociv1.Descriptor{}, fmt.Errorf("failed to resolve blob: %w", err)
-			}
-
-			return ref, desc, nil
+			return "", ociv1.Descriptor{}, errdefs.ErrNotFound
 		}
 
 		return "", ociv1.Descriptor{}, fmt.Errorf("failed to resolve manifest %q: %w", ref, err)
@@ -100,15 +94,16 @@ func (c *Client) Push(ctx context.Context, d ociv1.Descriptor, src regclient.Sou
 		return nil, err
 	}
 
-	repository, err := c.resolveRef(c.Ref)
+	repository, err := c.createRepository(c.Ref)
 	if err != nil {
 		return nil, err
 	}
 
 	if split := strings.Split(c.Ref, ":"); len(split) == 2 {
 		// Once we get a reference that contains a tag, we need to re-push that
-		// layer with the reference included. PushReference pushes a blob or a
-		// manifest.
+		// layer with the reference included. PushReference then will tag
+		// that layer resulting in the created tag pointing to the right
+		// blob data.
 		if err := repository.PushReference(ctx, d, reader, c.Ref); err != nil {
 			return nil, fmt.Errorf("failed to push tag: %w", err)
 		}
@@ -126,14 +121,17 @@ func (c *Client) Push(ctx context.Context, d ociv1.Descriptor, src regclient.Sou
 }
 
 func (c *Client) Fetch(ctx context.Context, desc ociv1.Descriptor) (io.ReadCloser, error) {
-	src, err := c.resolveRef(c.Ref)
+	src, err := c.createRepository(c.Ref)
 	if err != nil {
 		return nil, fmt.Errorf("failed to resolve ref %q: %w", c.Ref, err)
 	}
 
+	// oras requires a Resolve to happen before a fetch because
+	// -1 is an invalid size.
 	// manifest is not set in the descriptor
-	// src.Resolve is a manifest().resolve
-	rdesc, err := src.Resolve(ctx, desc.Digest.String())
+	// We explicitly call resolve on manifest first because it might be
+	// that the mediatype is not set at this point.
+	rdesc, err := src.Manifests().Resolve(ctx, desc.Digest.String())
 	if err != nil {
 		if strings.Contains(err.Error(), "not found") {
 			rdesc, err = src.Blobs().Resolve(ctx, desc.Digest.String())
@@ -150,6 +148,7 @@ func (c *Client) Fetch(ctx context.Context, desc ociv1.Descriptor) (io.ReadClose
 		return nil, fmt.Errorf("failed to resolve fetch manifest %q: %w", desc.Digest.String(), err)
 	}
 
+	// lastly, try a manifest fetch.
 	fetch, err := src.Fetch(ctx, rdesc)
 	if err != nil {
 		return nil, fmt.Errorf("failed to fetch manifest: %w", err)
@@ -160,7 +159,7 @@ func (c *Client) Fetch(ctx context.Context, desc ociv1.Descriptor) (io.ReadClose
 
 func (c *Client) List(ctx context.Context) ([]string, error) {
 	var result []string
-	src, err := c.resolveRef(c.Ref)
+	src, err := c.createRepository(c.Ref)
 	if err != nil {
 		return nil, fmt.Errorf("failed to resolve ref %q: %w", c.Ref, err)
 	}
@@ -175,7 +174,7 @@ func (c *Client) List(ctx context.Context) ([]string, error) {
 	return result, nil
 }
 
-func (c *Client) resolveRef(ref string) (*remote.Repository, error) {
+func (c *Client) createRepository(ref string) (*remote.Repository, error) {
 	src, err := remote.NewRepository(ref)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create new repository: %w", err)