image: set MediaType in OCI manifests

In image-spec 1.0.2, the MediaType field is now available in OCI
manifests, so set it.

Update the imgtype helper to output the MediaType field as-is from OCI
image manifests instead of just always supplying the expected value.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/onsi/ginkgo v1.16.5
 	github.com/onsi/gomega v1.17.0
 	github.com/opencontainers/go-digest v1.0.0
-	github.com/opencontainers/image-spec v1.0.2-0.20210819154149-5ad6f50d6283
+	github.com/opencontainers/image-spec v1.0.2-0.20211123152302-43a7dee1ec31
 	github.com/opencontainers/runc v1.0.2
 	github.com/opencontainers/runtime-spec v1.0.3-0.20210326190908-1c3f411f0417
 	github.com/opencontainers/runtime-tools v0.9.0

go.sum

@@ -686,6 +686,8 @@ github.com/opencontainers/image-spec v1.0.0/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zM
 github.com/opencontainers/image-spec v1.0.1/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
 github.com/opencontainers/image-spec v1.0.2-0.20210819154149-5ad6f50d6283 h1:TVzvdjOalkJBNkbpPVMAr4KV9QRf2IjfxdyxwAK78Gs=
 github.com/opencontainers/image-spec v1.0.2-0.20210819154149-5ad6f50d6283/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
+github.com/opencontainers/image-spec v1.0.2-0.20211123152302-43a7dee1ec31 h1:Wh4aR2I6JFwySre9m3iHJYuMnvUFE/HT6qAXozRWi/E=
+github.com/opencontainers/image-spec v1.0.2-0.20211123152302-43a7dee1ec31/go.mod h1:BtxoFyWECRxE4U/7sNtV5W15zMzWCbyJoFRP3s7yZA0=
 github.com/opencontainers/runc v0.0.0-20190115041553-12f6a991201f/go.mod h1:qT5XzbpPznkRYVz/mWwUaVBUv2rmF59PVA73FjuZG0U=
 github.com/opencontainers/runc v0.1.1/go.mod h1:qT5XzbpPznkRYVz/mWwUaVBUv2rmF59PVA73FjuZG0U=
 github.com/opencontainers/runc v1.0.0-rc8.0.20190926000215-3e425f80a8c9/go.mod h1:qT5XzbpPznkRYVz/mWwUaVBUv2rmF59PVA73FjuZG0U=

image.go

@@ -239,6 +239,7 @@ func (i *containerImageRef) createConfigsAndManifests() (v1.Image, v1.Manifest,
 		Versioned: specs.Versioned{
 			SchemaVersion: 2,
 		},
+		MediaType: v1.MediaTypeImageManifest,
 		Config: v1.Descriptor{
 			MediaType: v1.MediaTypeImageConfig,
 		},

internal/source/create.go

@@ -54,6 +54,7 @@ func Create(ctx context.Context, sourcePath string, options CreateOptions) error
 	// Create and write the manifest.
 	manifest := specV1.Manifest{
 		Versioned: spec.Versioned{SchemaVersion: 2},
+		MediaType: specV1.MediaTypeImageManifest,
 		Config: specV1.Descriptor{
 			MediaType: MediaTypeSourceImageConfig,
 			Digest:    configBlob.Digest,

pkg/blobcache/blobcache_test.go

@@ -102,6 +102,7 @@ func TestBlobCache(t *testing.T) {
 					Versioned: specs.Versioned{
 						SchemaVersion: 2,
 					},
+					MediaType: v1.MediaTypeImageManifest,
 					Config: v1.Descriptor{
 						MediaType: v1.MediaTypeImageConfig,
 						Digest:    configInfo.Digest,

tests/imgtype/imgtype.go

@@ -159,7 +159,7 @@ func main() {
 				errors = true
 				continue
 			}
-			manifestType = v1.MediaTypeImageManifest
+			manifestType = oManifest.MediaType
 			configType = oManifest.Config.MediaType
 		case define.Dockerv2ImageManifest:
 			err = json.Unmarshal(manifest, &dManifest)

vendor/modules.txt

@@ -384,7 +384,7 @@ github.com/onsi/gomega/matchers/support/goraph/util
 github.com/onsi/gomega/types
 # github.com/opencontainers/go-digest v1.0.0
 github.com/opencontainers/go-digest
-# github.com/opencontainers/image-spec v1.0.2-0.20210819154149-5ad6f50d6283
+# github.com/opencontainers/image-spec v1.0.2-0.20211123152302-43a7dee1ec31
 github.com/opencontainers/image-spec/specs-go
 github.com/opencontainers/image-spec/specs-go/v1
 # github.com/opencontainers/runc v1.0.2