adds support for oci manifests and manifestlists

Signed-off-by: Mike Brown <brownwm@us.ibm.com>

manifest/ocischema/manifest_test.go

@@ -0,0 +1,111 @@
+package ocischema
+
+import (
+	"bytes"
+	"encoding/json"
+	"reflect"
+	"testing"
+
+	"github.com/docker/distribution"
+)
+
+var expectedManifestSerialization = []byte(`{
+   "schemaVersion": 2,
+   "mediaType": "application/vnd.oci.image.manifest.v1+json",
+   "config": {
+      "mediaType": "application/vnd.oci.image.config.v1+json",
+      "size": 985,
+      "digest": "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b"
+   },
+   "layers": [
+      {
+         "mediaType": "application/vnd.oci.image.layer.v1.tar+gzip",
+         "size": 153263,
+         "digest": "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b"
+      }
+   ]
+}`)
+
+func TestManifest(t *testing.T) {
+	manifest := Manifest{
+		Versioned: SchemaVersion,
+		Config: distribution.Descriptor{
+			Digest:    "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b",
+			Size:      985,
+			MediaType: MediaTypeConfig,
+		},
+		Layers: []distribution.Descriptor{
+			{
+				Digest:    "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b",
+				Size:      153263,
+				MediaType: MediaTypeLayer,
+			},
+		},
+	}
+
+	deserialized, err := FromStruct(manifest)
+	if err != nil {
+		t.Fatalf("error creating DeserializedManifest: %v", err)
+	}
+
+	mediaType, canonical, err := deserialized.Payload()
+
+	if mediaType != MediaTypeManifest {
+		t.Fatalf("unexpected media type: %s", mediaType)
+	}
+
+	// Check that the canonical field is the same as json.MarshalIndent
+	// with these parameters.
+	p, err := json.MarshalIndent(&manifest, "", "   ")
+	if err != nil {
+		t.Fatalf("error marshaling manifest: %v", err)
+	}
+	if !bytes.Equal(p, canonical) {
+		t.Fatalf("manifest bytes not equal: %q != %q", string(canonical), string(p))
+	}
+
+	// Check that canonical field matches expected value.
+	if !bytes.Equal(expectedManifestSerialization, canonical) {
+		t.Fatalf("manifest bytes not equal: %q != %q", string(canonical), string(expectedManifestSerialization))
+	}
+
+	var unmarshalled DeserializedManifest
+	if err := json.Unmarshal(deserialized.canonical, &unmarshalled); err != nil {
+		t.Fatalf("error unmarshaling manifest: %v", err)
+	}
+
+	if !reflect.DeepEqual(&unmarshalled, deserialized) {
+		t.Fatalf("manifests are different after unmarshaling: %v != %v", unmarshalled, *deserialized)
+	}
+
+	target := deserialized.Target()
+	if target.Digest != "sha256:1a9ec845ee94c202b2d5da74a24f0ed2058318bfa9879fa541efaecba272e86b" {
+		t.Fatalf("unexpected digest in target: %s", target.Digest.String())
+	}
+	if target.MediaType != MediaTypeConfig {
+		t.Fatalf("unexpected media type in target: %s", target.MediaType)
+	}
+	if target.Size != 985 {
+		t.Fatalf("unexpected size in target: %d", target.Size)
+	}
+
+	references := deserialized.References()
+	if len(references) != 2 {
+		t.Fatalf("unexpected number of references: %d", len(references))
+	}
+
+	if !reflect.DeepEqual(references[0], target) {
+		t.Fatalf("first reference should be target: %v != %v", references[0], target)
+	}
+
+	// Test the second reference
+	if references[1].Digest != "sha256:62d8908bee94c202b2d35224a221aaa2058318bfa9879fa541efaecba272331b" {
+		t.Fatalf("unexpected digest in reference: %s", references[0].Digest.String())
+	}
+	if references[1].MediaType != MediaTypeLayer {
+		t.Fatalf("unexpected media type in reference: %s", references[0].MediaType)
+	}
+	if references[1].Size != 153263 {
+		t.Fatalf("unexpected size in reference: %d", references[0].Size)
+	}
+}