exporter: remove wrappers for oci data types

opencontainers/image-spec now contains the MediaType field for all of
its structs. With this update, we can avoid manually wrapping the
internal data types to present this field.

This requires updating the expected digest for source-date-epoch, since
the ordering of JSON fields is now slightly different :)

Signed-off-by: Justin Chadwell <[email protected]>

Author: jedevc

exporter/containerimage/writer.go

@@ -178,19 +178,11 @@ func (ic *ImageWriter) Commit(ctx context.Context, inp *exporter.Source, session
 		return nil, err
 	}
 
-	idx := struct {
-		// MediaType is reserved in the OCI spec but
-		// excluded from go types.
-		MediaType string `json:"mediaType,omitempty"`
-
-		ocispecs.Index
-	}{
-		MediaType: ocispecs.MediaTypeImageIndex,
-		Index: ocispecs.Index{
-			Annotations: opts.Annotations.Platform(nil).Index,
-			Versioned: specs.Versioned{
-				SchemaVersion: 2,
-			},
+	idx := ocispecs.Index{
+		MediaType:   ocispecs.MediaTypeImageIndex,
+		Annotations: opts.Annotations.Platform(nil).Index,
+		Versioned: specs.Versioned{
+			SchemaVersion: 2,
 		},
 	}
 
@@ -386,24 +378,16 @@ func (ic *ImageWriter) commitDistributionManifest(ctx context.Context, opts *Ima
 		configType = images.MediaTypeDockerSchema2Config
 	}
 
-	mfst := struct {
-		// MediaType is reserved in the OCI spec but
-		// excluded from go types.
-		MediaType string `json:"mediaType,omitempty"`
-
-		ocispecs.Manifest
-	}{
-		MediaType: manifestType,
-		Manifest: ocispecs.Manifest{
-			Annotations: annotations.Manifest,
-			Versioned: specs.Versioned{
-				SchemaVersion: 2,
-			},
-			Config: ocispecs.Descriptor{
-				Digest:    configDigest,
-				Size:      int64(len(config)),
-				MediaType: configType,
-			},
+	mfst := ocispecs.Manifest{
+		MediaType:   manifestType,
+		Annotations: annotations.Manifest,
+		Versioned: specs.Versioned{
+			SchemaVersion: 2,
+		},
+		Config: ocispecs.Descriptor{
+			Digest:    configDigest,
+			Size:      int64(len(config)),
+			MediaType: configType,
 		},
 	}
 
@@ -499,23 +483,15 @@ func (ic *ImageWriter) commitAttestationsManifest(ctx context.Context, opts *Ima
 		MediaType: configType,
 	}
 
-	mfst := struct {
-		// MediaType is reserved in the OCI spec but
-		// excluded from go types.
-		MediaType string `json:"mediaType,omitempty"`
-
-		ocispecs.Manifest
-	}{
+	mfst := ocispecs.Manifest{
 		MediaType: manifestType,
-		Manifest: ocispecs.Manifest{
-			Versioned: specs.Versioned{
-				SchemaVersion: 2,
-			},
-			Config: ocispecs.Descriptor{
-				Digest:    configDigest,
-				Size:      int64(len(config)),
-				MediaType: configType,
-			},
+		Versioned: specs.Versioned{
+			SchemaVersion: 2,
+		},
+		Config: ocispecs.Descriptor{
+			Digest:    configDigest,
+			Size:      int64(len(config)),
+			MediaType: configType,
 		},
 	}
 

frontend/dockerfile/dockerfile_test.go

@@ -6518,7 +6518,7 @@ FROM scratch
 COPY --from=0 / /
 `)
 
-	const expectedDigest = "sha256:9e36395384d073e711102b13bd0ba4b779ef6afbaf5cadeb77fe77dba8967d1f"
+	const expectedDigest = "sha256:23bfe9c494f4b4ae9368d989035c70b3a34aa0bfc991618b3e54dcce2eee4bf8"
 
 	dir, err := integration.Tmpdir(
 		t,