Fix invalid layer index error

Signed-off-by: Vlad A. Ionescu <[email protected]>

cache/remotecache/v1/utils.go

@@ -5,18 +5,13 @@ import (
 	"fmt"
 	"sort"
 
-	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	"github.com/moby/buildkit/solver"
 	digest "github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
-// EmptyLayerRemovalSupported defines if implementation supports removal of empty layers. Buildkit image exporter
-// removes empty layers, but moby layerstore based implementation does not.
-var EmptyLayerRemovalSupported = true
-
 // sortConfig sorts the config structure to make sure it is deterministic
 func sortConfig(cc *CacheConfig) {
 	type indexedLayer struct {
@@ -303,10 +298,6 @@ func marshalRemote(ctx context.Context, r *solver.Remote, state *marshalState) s
 	}
 	desc := r.Descriptors[len(r.Descriptors)-1]
 
-	if desc.Digest == exptypes.EmptyGZLayer && EmptyLayerRemovalSupported {
-		return parentID
-	}
-
 	state.descriptors[desc.Digest] = DescriptorProviderPair{
 		Descriptor: desc,
 		Provider:   r.Provider,

client/client_test.go

@@ -2798,7 +2798,7 @@ func testBuildPushAndValidate(t *testing.T, sb integration.Sandbox) {
 	require.NotEqual(t, "", ociimg.Architecture)
 	require.NotEqual(t, "", ociimg.Config.WorkingDir)
 	require.Equal(t, "layers", ociimg.RootFS.Type)
-	require.Equal(t, 2, len(ociimg.RootFS.DiffIDs))
+	require.Equal(t, 3, len(ociimg.RootFS.DiffIDs))
 	require.NotNil(t, ociimg.Created)
 	require.True(t, time.Since(*ociimg.Created) < 2*time.Minute)
 	require.Condition(t, func() bool {
@@ -2815,7 +2815,7 @@ func testBuildPushAndValidate(t *testing.T, sb integration.Sandbox) {
 	require.Contains(t, ociimg.History[1].CreatedBy, "true")
 	require.Contains(t, ociimg.History[2].CreatedBy, "foo/sub/baz")
 	require.False(t, ociimg.History[0].EmptyLayer)
-	require.True(t, ociimg.History[1].EmptyLayer)
+	require.False(t, ociimg.History[1].EmptyLayer)
 	require.False(t, ociimg.History[2].EmptyLayer)
 
 	dt, err = content.ReadBlob(ctx, img.ContentStore(), img.Target())
@@ -2830,7 +2830,7 @@ func testBuildPushAndValidate(t *testing.T, sb integration.Sandbox) {
 	require.NoError(t, err)
 
 	require.Equal(t, images.MediaTypeDockerSchema2Manifest, mfst.MediaType)
-	require.Equal(t, 2, len(mfst.Layers))
+	require.Equal(t, 3, len(mfst.Layers))
 	require.Equal(t, images.MediaTypeDockerSchema2LayerGzip, mfst.Layers[0].MediaType)
 	require.Equal(t, images.MediaTypeDockerSchema2LayerGzip, mfst.Layers[1].MediaType)
 
@@ -2857,7 +2857,7 @@ func testBuildPushAndValidate(t *testing.T, sb integration.Sandbox) {
 	_, ok = m["foo/sub/baz"]
 	require.False(t, ok)
 
-	dt, err = content.ReadBlob(ctx, img.ContentStore(), ocispecs.Descriptor{Digest: mfst.Layers[1].Digest})
+	dt, err = content.ReadBlob(ctx, img.ContentStore(), ocispecs.Descriptor{Digest: mfst.Layers[2].Digest})
 	require.NoError(t, err)
 
 	m, err = testutil.ReadTarToMap(dt, true)

exporter/containerimage/exptypes/types.go

@@ -1,7 +1,6 @@
 package exptypes
 
 import (
-	digest "github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
@@ -16,8 +15,6 @@ const (
 	ExporterPlatformsKey         = "refs.platforms"
 )
 
-const EmptyGZLayer = digest.Digest("sha256:4f4fb700ef54461cfa02571ae0db9a0dc1e0cdb5577484a6d75e68dc38e8acc1")
-
 type Platforms struct {
 	Platforms []Platform
 }

exporter/containerimage/writer.go

@@ -476,15 +476,10 @@ func normalizeLayersAndHistory(ctx context.Context, remote *solver.Remote, histo
 	var layerIndex int
 	for i, h := range history {
 		if !h.EmptyLayer {
-			if remote.Descriptors[layerIndex].Digest == exptypes.EmptyGZLayer {
-				h.EmptyLayer = true
-				remote.Descriptors = append(remote.Descriptors[:layerIndex], remote.Descriptors[layerIndex+1:]...)
-			} else {
-				if h.Created == nil {
-					h.Created = refMeta[layerIndex].createdAt
-				}
-				layerIndex++
+			if h.Created == nil {
+				h.Created = refMeta[layerIndex].createdAt
 			}
+			layerIndex++
 		}
 		history[i] = h
 	}

frontend/dockerfile/dockerfile_test.go

@@ -2946,7 +2946,7 @@ RUN ["ls"]
 
 	require.Equal(t, "layers", ociimg.RootFS.Type)
 	// this depends on busybox. should be ok after freezing images
-	require.Equal(t, 3, len(ociimg.RootFS.DiffIDs))
+	require.Equal(t, 4, len(ociimg.RootFS.DiffIDs))
 
 	require.Equal(t, 7, len(ociimg.History))
 	require.Contains(t, ociimg.History[2].CreatedBy, "lbl=val")
@@ -2962,7 +2962,7 @@ RUN ["ls"]
 	require.Equal(t, false, ociimg.History[5].EmptyLayer)
 	require.NotNil(t, ociimg.History[5].Created)
 	require.Contains(t, ociimg.History[6].CreatedBy, "RUN ls")
-	require.Equal(t, true, ociimg.History[6].EmptyLayer)
+	require.Equal(t, false, ociimg.History[6].EmptyLayer)
 	require.NotNil(t, ociimg.History[6].Created)
 }
 

snapshot/imagerefchecker/checker.go

@@ -9,7 +9,6 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/images"
 	"github.com/moby/buildkit/cache"
-	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	digest "github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
@@ -90,9 +89,7 @@ func toDigests(layers []ocispecs.Descriptor) []digest.Digest {
 func layerKey(layers []digest.Digest) string {
 	b := &strings.Builder{}
 	for _, l := range layers {
-		if l != exptypes.EmptyGZLayer {
-			b.Write([]byte(l))
-		}
+		b.Write([]byte(l))
 	}
 	return b.String()
 }