test: add basic integration tests

Signed-off-by: Justin Chadwell <me@jedevc.com>

vendor/github.com/moby/buildkit/util/testutil/imageinfo.go

@@ -0,0 +1,130 @@
+package testutil
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/platforms"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+type ImageInfo struct {
+	Desc         ocispecs.Descriptor
+	Manifest     ocispecs.Manifest
+	Img          ocispecs.Image
+	Layers       []map[string]*TarItem
+	LayersRaw    [][]byte
+	descPlatform string
+}
+
+type ImagesInfo struct {
+	Desc   ocispecs.Descriptor
+	Index  ocispecs.Index
+	Images []*ImageInfo
+}
+
+func (idx ImagesInfo) Find(platform string) *ImageInfo {
+	result := idx.Filter(platform)
+	if len(result.Images) == 0 {
+		return nil
+	}
+	return result.Images[0]
+}
+
+func (idx ImagesInfo) Filter(platform string) *ImagesInfo {
+	result := &ImagesInfo{Desc: idx.Desc}
+	for _, info := range idx.Images {
+		if info.descPlatform == platform {
+			result.Images = append(result.Images, info)
+		}
+	}
+	return result
+}
+
+func (idx ImagesInfo) FindAttestation(platform string) *ImageInfo {
+	img := idx.Find(platform)
+	if img == nil {
+		return nil
+	}
+	for _, info := range idx.Images {
+		if info.Desc.Annotations["vnd.docker.reference.digest"] == string(img.Desc.Digest) {
+			return info
+		}
+	}
+	return nil
+}
+
+func ReadImages(ctx context.Context, p content.Provider, desc ocispecs.Descriptor) (*ImagesInfo, error) {
+	idx := &ImagesInfo{Desc: desc}
+
+	dt, err := content.ReadBlob(ctx, p, desc)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(dt, &idx.Index); err != nil {
+		return nil, err
+	}
+	if !images.IsIndexType(idx.Index.MediaType) {
+		img, err := ReadImage(ctx, p, desc)
+		if err != nil {
+			return nil, err
+		}
+		img.descPlatform = platforms.Format(img.Img.Platform)
+		idx.Images = append(idx.Images, img)
+		return idx, nil
+	}
+
+	for _, m := range idx.Index.Manifests {
+		img, err := ReadImage(ctx, p, m)
+		if err != nil {
+			return nil, err
+		}
+		img.descPlatform = platforms.Format(*m.Platform)
+		idx.Images = append(idx.Images, img)
+	}
+	return idx, nil
+}
+
+func ReadImage(ctx context.Context, p content.Provider, desc ocispecs.Descriptor) (*ImageInfo, error) {
+	ii := &ImageInfo{Desc: desc}
+
+	dt, err := content.ReadBlob(ctx, p, desc)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(dt, &ii.Manifest); err != nil {
+		return nil, err
+	}
+	if !images.IsManifestType(ii.Manifest.MediaType) {
+		return nil, errors.Errorf("invalid manifest type %s", ii.Manifest.MediaType)
+	}
+
+	dt, err = content.ReadBlob(ctx, p, ii.Manifest.Config)
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(dt, &ii.Img); err != nil {
+		return nil, err
+	}
+
+	ii.Layers = make([]map[string]*TarItem, len(ii.Manifest.Layers))
+	ii.LayersRaw = make([][]byte, len(ii.Manifest.Layers))
+	for i, l := range ii.Manifest.Layers {
+		dt, err := content.ReadBlob(ctx, p, l)
+		if err != nil {
+			return nil, err
+		}
+		ii.LayersRaw[i] = dt
+		if images.IsLayerType(l.MediaType) {
+			m, err := ReadTarToMap(dt, true)
+			if err != nil {
+				return nil, err
+			}
+			ii.Layers[i] = m
+		}
+	}
+	return ii, nil
+}