feature: support to print snapshot info

Signed-off-by: ningmingxiao <ning.mingxiao@zte.com.cn>

Author: ningmingxiao

pkg/imageinspector/imageinspector.go

@@ -18,6 +18,10 @@ package imageinspector
 
 import (
 	"context"
+	"crypto/sha256"
+	"fmt"
+
+	"github.com/opencontainers/go-digest"
 
 	containerd "github.com/containerd/containerd/v2/client"
 	"github.com/containerd/containerd/v2/core/images"
@@ -56,6 +60,18 @@ func Inspect(ctx context.Context, client *containerd.Client, image images.Image,
 	} else {
 		n.ImageConfigDesc = imageConfigDesc
 		n.ImageConfig = imageConfig
+		diffIDS := imageConfig.RootFS.DiffIDs
+		chainIDS := calculateChainID(diffIDS)
+		snapshots := make([]snapshots.Info, len(chainIDS))
+		for i, id := range chainIDS {
+			snapInfo, err := snapshotter.Stat(ctx, id.String())
+			if err == nil {
+				snapshots[i] = snapInfo
+			} else {
+				log.G(ctx).WithError(err).WithField("id", image.Name).Warnf("failed to get snapshot %s info", id.String())
+			}
+		}
+		n.Snapshots = snapshots
 	}
 	n.Size, err = imgutil.UnpackedImageSize(ctx, snapshotter, img)
 	if err != nil {
@@ -65,3 +81,17 @@ func Inspect(ctx context.Context, client *containerd.Client, image images.Image,
 
 	return n, nil
 }
+
+func calculateChainID(diffIDs []digest.Digest) []digest.Digest {
+	if len(diffIDs) == 0 {
+		return nil
+	}
+	chainIDs := make([]digest.Digest, len(diffIDs))
+	chainIDs[0] = diffIDs[0]
+	for i := 1; i < len(diffIDs); i++ {
+		combined := chainIDs[i-1] + " " + diffIDs[i]
+		hash := sha256.Sum256([]byte(combined))
+		chainIDs[i] = digest.FromString(fmt.Sprintf("sha256:%x", hash))
+	}
+	return chainIDs
+}

pkg/inspecttypes/native/image.go

@@ -20,6 +20,7 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 
 	"github.com/containerd/containerd/v2/core/images"
+	"github.com/containerd/containerd/v2/core/snapshots"
 )
 
 // Image corresponds to a containerd-native image object.
@@ -34,4 +35,5 @@ type Image struct {
 	ImageConfigDesc ocispec.Descriptor `json:"ImageConfigDesc"`
 	ImageConfig     ocispec.Image      `json:"ImageConfig"`
 	Size            int64              `json:"size"`
+	Snapshots       []snapshots.Info   `json:"Snapshots,omitempty"`
 }