Dedupe "containerd.io/uncompressed" constants and literals

Dedupe the several "containerd.io/uncompressed" constants and literals
into `github.com/containerd/containerd/labels.LabelUncompressed`

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

cache/blobs.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/containerd/containerd/diff"
 	"github.com/containerd/containerd/diff/walking"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	"github.com/containerd/containerd/mount"
 	"github.com/moby/buildkit/session"
@@ -25,8 +26,6 @@ import (
 var g flightcontrol.Group[struct{}]
 var gFileList flightcontrol.Group[[]string]
 
-const containerdUncompressed = "containerd.io/uncompressed"
-
 var ErrNoBlobs = errors.Errorf("no blobs for snapshot")
 
 // computeBlobChain ensures every ref in a parent chain has an associated blob in the content store. If
@@ -231,10 +230,10 @@ func computeBlobChain(ctx context.Context, sr *immutableRef, createIfNeeded bool
 					return struct{}{}, err
 				}
 
-				if diffID, ok := info.Labels[containerdUncompressed]; ok {
-					desc.Annotations[containerdUncompressed] = diffID
+				if diffID, ok := info.Labels[labels.LabelUncompressed]; ok {
+					desc.Annotations[labels.LabelUncompressed] = diffID
 				} else if mediaType == ocispecs.MediaTypeImageLayer {
-					desc.Annotations[containerdUncompressed] = desc.Digest.String()
+					desc.Annotations[labels.LabelUncompressed] = desc.Digest.String()
 				} else {
 					return struct{}{}, errors.Errorf("unknown layer compression type")
 				}

cache/blobs_linux.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
+	labelspkg "github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/mount"
 	"github.com/moby/buildkit/util/bklog"
 	"github.com/moby/buildkit/util/compression"
@@ -69,7 +70,7 @@ func (sr *immutableRef) tryComputeOverlayBlob(ctx context.Context, lower, upper
 		if labels == nil {
 			labels = map[string]string{}
 		}
-		labels[containerdUncompressed] = dgstr.Digest().String()
+		labels[labelspkg.LabelUncompressed] = dgstr.Digest().String()
 	} else {
 		if err = overlay.WriteUpperdir(ctx, bufW, upperdir, lower); err != nil {
 			return emptyDesc, false, errors.Wrap(err, "failed to write diff")
@@ -101,9 +102,9 @@ func (sr *immutableRef) tryComputeOverlayBlob(ctx context.Context, lower, upper
 		cinfo.Labels = make(map[string]string)
 	}
 	// Set uncompressed label if digest already existed without label
-	if _, ok := cinfo.Labels[containerdUncompressed]; !ok {
-		cinfo.Labels[containerdUncompressed] = labels[containerdUncompressed]
-		if _, err := sr.cm.ContentStore.Update(ctx, cinfo, "labels."+containerdUncompressed); err != nil {
+	if _, ok := cinfo.Labels[labelspkg.LabelUncompressed]; !ok {
+		cinfo.Labels[labelspkg.LabelUncompressed] = labels[labelspkg.LabelUncompressed]
+		if _, err := sr.cm.ContentStore.Update(ctx, cinfo, "labels."+labelspkg.LabelUncompressed); err != nil {
 			return emptyDesc, false, errors.Wrap(err, "error setting uncompressed label")
 		}
 	}

cache/compression_nydus.go

@@ -109,7 +109,7 @@ func MergeNydus(ctx context.Context, ref ImmutableRef, comp compression.Config,
 
 	compressedDgst := cw.Digest()
 	if err := cw.Commit(ctx, 0, compressedDgst, content.WithLabels(map[string]string{
-		containerdUncompressed: uncompressedDgst.Digest().String(),
+		labels.LabelUncompressed: uncompressedDgst.Digest().String(),
 	})); err != nil {
 		if !errdefs.IsAlreadyExists(err) {
 			return nil, errors.Wrap(err, "commit to content store")
@@ -129,7 +129,7 @@ func MergeNydus(ctx context.Context, ref ImmutableRef, comp compression.Config,
 		Size:      info.Size,
 		MediaType: ocispecs.MediaTypeImageLayerGzip,
 		Annotations: map[string]string{
-			containerdUncompressed: uncompressedDgst.Digest().String(),
+			labels.LabelUncompressed: uncompressedDgst.Digest().String(),
 			// Use this annotation to identify nydus bootstrap layer.
 			converter.LayerAnnotationNydusBootstrap: "true",
 		},

cache/manager.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/filters"
 	"github.com/containerd/containerd/gc"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/moby/buildkit/cache/metadata"
@@ -1657,7 +1658,7 @@ func sortDeleteRecords(toDelete []*deleteRecord) {
 }
 
 func diffIDFromDescriptor(desc ocispecs.Descriptor) (digest.Digest, error) {
-	diffIDStr, ok := desc.Annotations["containerd.io/uncompressed"]
+	diffIDStr, ok := desc.Annotations[labels.LabelUncompressed]
 	if !ok {
 		return "", errors.Errorf("missing uncompressed annotation for %s", desc.Digest)
 	}

cache/manager_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/containerd/containerd/diff/apply"
 	"github.com/containerd/containerd/diff/walking"
 	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	ctdmetadata "github.com/containerd/containerd/metadata"
 	"github.com/containerd/containerd/mount"
@@ -731,7 +732,7 @@ func TestSetBlob(t *testing.T) {
 	err = snap.(*immutableRef).setBlob(ctx, ocispecs.Descriptor{
 		Digest: digest.FromBytes([]byte("foobar")),
 		Annotations: map[string]string{
-			"containerd.io/uncompressed": digest.FromBytes([]byte("foobar2")).String(),
+			labels.LabelUncompressed: digest.FromBytes([]byte("foobar2")).String(),
 		},
 	})
 	require.Error(t, err)
@@ -742,7 +743,7 @@ func TestSetBlob(t *testing.T) {
 	require.NoError(t, err)
 
 	snapRef = snap.(*immutableRef)
-	require.Equal(t, desc.Annotations["containerd.io/uncompressed"], string(snapRef.getDiffID()))
+	require.Equal(t, desc.Annotations[labels.LabelUncompressed], string(snapRef.getDiffID()))
 	require.Equal(t, desc.Digest, snapRef.getBlob())
 	require.Equal(t, desc.MediaType, snapRef.getMediaType())
 	require.Equal(t, snapRef.getDiffID(), snapRef.getChainID())
@@ -768,7 +769,7 @@ func TestSetBlob(t *testing.T) {
 	require.NoError(t, err)
 
 	snapRef2 := snap2.(*immutableRef)
-	require.Equal(t, desc2.Annotations["containerd.io/uncompressed"], string(snapRef2.getDiffID()))
+	require.Equal(t, desc2.Annotations[labels.LabelUncompressed], string(snapRef2.getDiffID()))
 	require.Equal(t, desc2.Digest, snapRef2.getBlob())
 	require.Equal(t, desc2.MediaType, snapRef2.getMediaType())
 	require.Equal(t, digest.FromBytes([]byte(snapRef.getChainID()+" "+snapRef2.getDiffID())), snapRef2.getChainID())
@@ -786,7 +787,7 @@ func TestSetBlob(t *testing.T) {
 	require.NoError(t, err)
 
 	snapRef3 := snap3.(*immutableRef)
-	require.Equal(t, desc3.Annotations["containerd.io/uncompressed"], string(snapRef3.getDiffID()))
+	require.Equal(t, desc3.Annotations[labels.LabelUncompressed], string(snapRef3.getDiffID()))
 	require.Equal(t, desc3.Digest, snapRef3.getBlob())
 	require.Equal(t, desc3.MediaType, snapRef3.getMediaType())
 	require.Equal(t, digest.FromBytes([]byte(snapRef.getChainID()+" "+snapRef3.getDiffID())), snapRef3.getChainID())
@@ -804,7 +805,7 @@ func TestSetBlob(t *testing.T) {
 	b5, desc5, err := mapToBlob(map[string]string{"foo5": "bar5"}, true)
 	require.NoError(t, err)
 
-	desc5.Annotations["containerd.io/uncompressed"] = snapRef2.getDiffID().String()
+	desc5.Annotations[labels.LabelUncompressed] = snapRef2.getDiffID().String()
 
 	err = content.WriteBlob(ctx, co.cs, "ref5", bytes.NewBuffer(b5), desc5)
 	require.NoError(t, err)
@@ -833,7 +834,7 @@ func TestSetBlob(t *testing.T) {
 	require.NoError(t, err)
 
 	snapRef6 := snap6.(*immutableRef)
-	require.Equal(t, desc6.Annotations["containerd.io/uncompressed"], string(snapRef6.getDiffID()))
+	require.Equal(t, desc6.Annotations[labels.LabelUncompressed], string(snapRef6.getDiffID()))
 	require.Equal(t, desc6.Digest, snapRef6.getBlob())
 	require.Equal(t, digest.FromBytes([]byte(snapRef3.getChainID()+" "+snapRef6.getDiffID())), snapRef6.getChainID())
 	require.Equal(t, digest.FromBytes([]byte(snapRef3.getBlobChainID()+" "+digest.FromBytes([]byte(snapRef6.getBlob()+" "+snapRef6.getDiffID())))), snapRef6.getBlobChainID())
@@ -843,7 +844,7 @@ func TestSetBlob(t *testing.T) {
 	_, err = cm.GetByBlob(ctx, ocispecs.Descriptor{
 		Digest: digest.FromBytes([]byte("notexist")),
 		Annotations: map[string]string{
-			"containerd.io/uncompressed": digest.FromBytes([]byte("notexist")).String(),
+			labels.LabelUncompressed: digest.FromBytes([]byte("notexist")).String(),
 		},
 	}, snap3)
 	require.Error(t, err)
@@ -1584,7 +1585,7 @@ func TestConversion(t *testing.T) {
 					}
 					require.Equal(t, recreatedDesc.Digest, orgDesc.Digest, testName)
 					require.NotNil(t, recreatedDesc.Annotations)
-					require.Equal(t, recreatedDesc.Annotations["containerd.io/uncompressed"], orgDesc.Digest.String(), testName)
+					require.Equal(t, recreatedDesc.Annotations[labels.LabelUncompressed], orgDesc.Digest.String(), testName)
 					return nil
 				})
 			}
@@ -1965,7 +1966,7 @@ func checkInfo(ctx context.Context, t *testing.T, cs content.Store, info content
 	if info.Labels == nil {
 		return
 	}
-	uncompressedDgst, ok := info.Labels[containerdUncompressed]
+	uncompressedDgst, ok := info.Labels[labels.LabelUncompressed]
 	if !ok {
 		return
 	}
@@ -1987,7 +1988,7 @@ func checkDescriptor(ctx context.Context, t *testing.T, cs content.Store, desc o
 	}
 
 	// Check annotations exist
-	uncompressedDgst, ok := desc.Annotations[containerdUncompressed]
+	uncompressedDgst, ok := desc.Annotations[labels.LabelUncompressed]
 	require.True(t, ok, "uncompressed digest annotation not found: %q", desc.Digest)
 	var uncompressedSize int64
 	if compressionType == compression.EStargz {
@@ -2579,7 +2580,7 @@ func mapToBlobWithCompression(m map[string]string, compress func(io.Writer) (io.
 		MediaType: mediaType,
 		Size:      int64(buf.Len()),
 		Annotations: map[string]string{
-			"containerd.io/uncompressed": sha.Digest().String(),
+			labels.LabelUncompressed: sha.Digest().String(),
 		},
 	}, nil
 }
@@ -2631,7 +2632,7 @@ func fileToBlob(file *os.File, compress bool) ([]byte, ocispecs.Descriptor, erro
 		MediaType: mediaType,
 		Size:      int64(buf.Len()),
 		Annotations: map[string]string{
-			"containerd.io/uncompressed": sha.Digest().String(),
+			labels.LabelUncompressed: sha.Digest().String(),
 		},
 	}, nil
 }
@@ -2688,7 +2689,7 @@ func mapToSystemTarBlob(t *testing.T, m map[string]string) ([]byte, ocispecs.Des
 		MediaType: ocispecs.MediaTypeImageLayer,
 		Size:      int64(len(tarout)),
 		Annotations: map[string]string{
-			"containerd.io/uncompressed": digest.FromBytes(tarout).String(),
+			labels.LabelUncompressed: digest.FromBytes(tarout).String(),
 		},
 	}, nil
 }

cache/refs.go

@@ -12,6 +12,7 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	"github.com/containerd/containerd/mount"
 	"github.com/containerd/containerd/pkg/userns"
@@ -39,7 +40,7 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
-var additionalAnnotations = append(compression.EStargzAnnotations, containerdUncompressed)
+var additionalAnnotations = append(compression.EStargzAnnotations, labels.LabelUncompressed)
 
 // Ref is a reference to cacheable objects.
 type Ref interface {
@@ -733,7 +734,7 @@ func (sr *immutableRef) ociDesc(ctx context.Context, dhs DescHandlers, preferNon
 
 	diffID := sr.getDiffID()
 	if diffID != "" {
-		desc.Annotations["containerd.io/uncompressed"] = string(diffID)
+		desc.Annotations[labels.LabelUncompressed] = string(diffID)
 	}
 
 	createdAt := sr.GetCreatedAt()

cache/remotecache/azblob/exporter.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob"
 	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/labels"
 	"github.com/moby/buildkit/cache/remotecache"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
@@ -72,7 +73,7 @@ func (ce *exporter) Finalize(ctx context.Context) (map[string]string, error) {
 			return nil, errors.Errorf("invalid descriptor without annotations")
 		}
 		var diffID digest.Digest
-		v, ok := dgstPair.Descriptor.Annotations["containerd.io/uncompressed"]
+		v, ok := dgstPair.Descriptor.Annotations[labels.LabelUncompressed]
 		if !ok {
 			return nil, errors.Errorf("invalid descriptor without uncompressed annotation")
 		}

cache/remotecache/azblob/importer.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob"
 	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/labels"
 	"github.com/moby/buildkit/cache/remotecache"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
@@ -147,7 +148,7 @@ func (ci *importer) makeDescriptorProviderPair(l v1.CacheLayer) (*v1.DescriptorP
 	if l.Annotations.DiffID == "" {
 		return nil, errors.Errorf("cache layer with missing diffid")
 	}
-	annotations["containerd.io/uncompressed"] = l.Annotations.DiffID.String()
+	annotations[labels.LabelUncompressed] = l.Annotations.DiffID.String()
 	if !l.Annotations.CreatedAt.IsZero() {
 		txt, err := l.Annotations.CreatedAt.MarshalText()
 		if err != nil {

cache/remotecache/gha/gha.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/labels"
 	"github.com/moby/buildkit/cache/remotecache"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
@@ -133,7 +134,7 @@ func (ce *exporter) Finalize(ctx context.Context) (map[string]string, error) {
 			return nil, errors.Errorf("invalid descriptor without annotations")
 		}
 		var diffID digest.Digest
-		v, ok := dgstPair.Descriptor.Annotations["containerd.io/uncompressed"]
+		v, ok := dgstPair.Descriptor.Annotations[labels.LabelUncompressed]
 		if !ok {
 			return nil, errors.Errorf("invalid descriptor without uncompressed annotation")
 		}
@@ -226,7 +227,7 @@ func (ci *importer) makeDescriptorProviderPair(l v1.CacheLayer) (*v1.DescriptorP
 	if l.Annotations.DiffID == "" {
 		return nil, errors.Errorf("cache layer with missing diffid")
 	}
-	annotations["containerd.io/uncompressed"] = l.Annotations.DiffID.String()
+	annotations[labels.LabelUncompressed] = l.Annotations.DiffID.String()
 	if !l.Annotations.CreatedAt.IsZero() {
 		txt, err := l.Annotations.CreatedAt.MarshalText()
 		if err != nil {

cache/remotecache/import.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/solver"
@@ -221,7 +222,7 @@ func (ci *contentCacheImporter) importInlineCache(ctx context.Context, dt []byte
 					if createdBy := createdMsg[i]; createdBy != "" {
 						m.Annotations["buildkit/description"] = createdBy
 					}
-					m.Annotations["containerd.io/uncompressed"] = img.Rootfs.DiffIDs[i].String()
+					m.Annotations[labels.LabelUncompressed] = img.Rootfs.DiffIDs[i].String()
 					layers[m.Digest] = v1.DescriptorProviderPair{
 						Descriptor: m,
 						Provider:   ci.provider,

cache/remotecache/inline/inline.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 
+	"github.com/containerd/containerd/labels"
 	"github.com/moby/buildkit/cache/remotecache"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
@@ -67,7 +68,7 @@ func (ce *exporter) ExportForLayers(ctx context.Context, layers []digest.Digest)
 		}
 		// fallback for uncompressed digests
 		for _, v := range descs {
-			if uc := v.Descriptor.Annotations["containerd.io/uncompressed"]; uc == string(k) {
+			if uc := v.Descriptor.Annotations[labels.LabelUncompressed]; uc == string(k) {
 				descs2[v.Descriptor.Digest] = v
 				layerBlobDigests[i] = v.Descriptor.Digest
 			}

cache/remotecache/s3/s3.go

@@ -17,6 +17,7 @@ import (
 	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/aws/smithy-go"
 	"github.com/containerd/containerd/content"
+	"github.com/containerd/containerd/labels"
 	"github.com/moby/buildkit/cache/remotecache"
 	v1 "github.com/moby/buildkit/cache/remotecache/v1"
 	"github.com/moby/buildkit/session"
@@ -185,7 +186,7 @@ func (e *exporter) Finalize(ctx context.Context) (map[string]string, error) {
 		if dgstPair.Descriptor.Annotations == nil {
 			return nil, errors.Errorf("invalid descriptor without annotations")
 		}
-		v, ok := dgstPair.Descriptor.Annotations["containerd.io/uncompressed"]
+		v, ok := dgstPair.Descriptor.Annotations[labels.LabelUncompressed]
 		if !ok {
 			return nil, errors.Errorf("invalid descriptor without uncompressed annotation")
 		}
@@ -274,7 +275,7 @@ func (i *importer) makeDescriptorProviderPair(l v1.CacheLayer) (*v1.DescriptorPr
 		return nil, errors.Errorf("cache layer with missing diffid")
 	}
 	annotations := map[string]string{}
-	annotations["containerd.io/uncompressed"] = l.Annotations.DiffID.String()
+	annotations[labels.LabelUncompressed] = l.Annotations.DiffID.String()
 	if !l.Annotations.CreatedAt.IsZero() {
 		txt, err := l.Annotations.CreatedAt.MarshalText()
 		if err != nil {

exporter/containerimage/export.go

@@ -12,6 +12,7 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	"github.com/containerd/containerd/pkg/epoch"
 	"github.com/containerd/containerd/platforms"
@@ -454,7 +455,7 @@ func getLayers(ctx context.Context, descs []ocispecs.Descriptor, manifest ocispe
 	for i, desc := range descs {
 		layers[i].Diff = ocispecs.Descriptor{
 			MediaType: ocispecs.MediaTypeImageLayer,
-			Digest:    digest.Digest(desc.Annotations["containerd.io/uncompressed"]),
+			Digest:    digest.Digest(desc.Annotations[labels.LabelUncompressed]),
 		}
 		layers[i].Blob = manifest.Layers[i]
 	}

exporter/containerimage/writer.go

@@ -12,6 +12,7 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/diff"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/platforms"
 	intoto "github.com/in-toto/in-toto-golang/in_toto"
 	"github.com/moby/buildkit/cache"
@@ -443,8 +444,8 @@ func (ic *ImageWriter) commitAttestationsManifest(ctx context.Context, opts *Ima
 			Digest:    digest,
 			Size:      int64(len(data)),
 			Annotations: map[string]string{
-				"containerd.io/uncompressed": digest.String(),
-				"in-toto.io/predicate-type":  statement.PredicateType,
+				labels.LabelUncompressed:    digest.String(),
+				"in-toto.io/predicate-type": statement.PredicateType,
 			},
 		}
 
@@ -552,7 +553,7 @@ func attestationsConfig(layers []ocispecs.Descriptor) ([]byte, error) {
 	img.Variant = intotoPlatform.Variant
 	img.RootFS.Type = "layers"
 	for _, layer := range layers {
-		img.RootFS.DiffIDs = append(img.RootFS.DiffIDs, digest.Digest(layer.Annotations["containerd.io/uncompressed"]))
+		img.RootFS.DiffIDs = append(img.RootFS.DiffIDs, digest.Digest(layer.Annotations[labels.LabelUncompressed]))
 	}
 	dt, err := json.Marshal(img)
 	return dt, errors.Wrap(err, "failed to create attestations image config")
@@ -577,7 +578,7 @@ func patchImageConfig(dt []byte, descs []ocispecs.Descriptor, history []ocispecs
 	var rootFS ocispecs.RootFS
 	rootFS.Type = "layers"
 	for _, desc := range descs {
-		rootFS.DiffIDs = append(rootFS.DiffIDs, digest.Digest(desc.Annotations["containerd.io/uncompressed"]))
+		rootFS.DiffIDs = append(rootFS.DiffIDs, digest.Digest(desc.Annotations[labels.LabelUncompressed]))
 	}
 	dt, err := json.Marshal(rootFS)
 	if err != nil {
@@ -735,7 +736,7 @@ func RemoveInternalLayerAnnotations(in map[string]string, oci bool) map[string]s
 	for k, v := range in {
 		// oci supports annotations but don't export internal annotations
 		switch k {
-		case "containerd.io/uncompressed", "buildkit/createdat":
+		case labels.LabelUncompressed, "buildkit/createdat":
 			continue
 		default:
 			if strings.HasPrefix(k, "containerd.io/distribution.source.") {

util/compression/estargz.go

@@ -12,6 +12,7 @@ import (
 	cdcompression "github.com/containerd/containerd/archive/compression"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/stargz-snapshotter/estargz"
 	"github.com/moby/buildkit/util/iohelper"
 	digest "github.com/opencontainers/go-digest"
@@ -21,7 +22,6 @@ import (
 
 var EStargzAnnotations = []string{estargz.TOCJSONDigestAnnotation, estargz.StoreUncompressedSizeAnnotation}
 
-const containerdUncompressed = "containerd.io/uncompressed"
 const estargzLabel = "buildkit.io/compression/estargz"
 
 func (c estargzType) Compress(ctx context.Context, comp Config) (compressorFunc Compressor, finalize Finalizer) {
@@ -105,8 +105,8 @@ func (c estargzType) Compress(ctx context.Context, comp Config) (compressorFunc
 			if info.Labels == nil {
 				info.Labels = make(map[string]string)
 			}
-			info.Labels[containerdUncompressed] = cInfo.uncompressedDigest.String()
-			if _, err := cs.Update(ctx, info, "labels."+containerdUncompressed); err != nil {
+			info.Labels[labels.LabelUncompressed] = cInfo.uncompressedDigest.String()
+			if _, err := cs.Update(ctx, info, "labels."+labels.LabelUncompressed); err != nil {
 				return nil, err
 			}
 
@@ -114,7 +114,7 @@ func (c estargzType) Compress(ctx context.Context, comp Config) (compressorFunc
 			a := make(map[string]string)
 			a[estargz.TOCJSONDigestAnnotation] = cInfo.tocDigest.String()
 			a[estargz.StoreUncompressedSizeAnnotation] = fmt.Sprintf("%d", cInfo.uncompressedSize)
-			a[containerdUncompressed] = cInfo.uncompressedDigest.String()
+			a[labels.LabelUncompressed] = cInfo.uncompressedDigest.String()
 			return a, nil
 		}
 }

util/compression/nydus.go

@@ -56,14 +56,14 @@ func (c nydusType) Compress(ctx context.Context, comp Config) (compressorFunc Co
 			if info.Labels == nil {
 				info.Labels = make(map[string]string)
 			}
-			info.Labels[containerdUncompressed] = uncompressedDgst
-			if _, err := cs.Update(ctx, info, "labels."+containerdUncompressed); err != nil {
+			info.Labels[labels.LabelUncompressed] = uncompressedDgst
+			if _, err := cs.Update(ctx, info, "labels."+labels.LabelUncompressed); err != nil {
 				return nil, errors.Wrap(err, "update info to content store")
 			}
 
 			// Fill annotations
 			annotations := map[string]string{
-				containerdUncompressed: uncompressedDgst,
+				labels.LabelUncompressed: uncompressedDgst,
 				// Use this annotation to identify nydus blob layer.
 				nydusify.LayerAnnotationNydusBlob: "true",
 			}

util/pull/pull.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/reference"
 	"github.com/containerd/containerd/remotes"
@@ -273,7 +274,7 @@ func getLayers(ctx context.Context, provider content.Provider, desc ocispecs.Des
 		if desc.Annotations == nil {
 			desc.Annotations = map[string]string{}
 		}
-		desc.Annotations["containerd.io/uncompressed"] = diffIDs[i].String()
+		desc.Annotations[labels.LabelUncompressed] = diffIDs[i].String()
 		layers[i] = desc
 	}
 	return layers, nil

util/winlayers/differ.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/diff"
 	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/mount"
 	log "github.com/moby/buildkit/util/bklog"
 	digest "github.com/opencontainers/go-digest"
@@ -121,7 +122,7 @@ func (s *winDiffer) Compare(ctx context.Context, lower, upper []mount.Mount, opt
 				if config.Labels == nil {
 					config.Labels = map[string]string{}
 				}
-				config.Labels["containerd.io/uncompressed"] = dgstr.Digest().String()
+				config.Labels[labels.LabelUncompressed] = dgstr.Digest().String()
 			} else {
 				w, discard, done := makeWindowsLayer(ctx, cw)
 				if err = archive.WriteDiff(ctx, w, lowerRoot, upperRoot); err != nil {