nydus: adjust code structure for independence

Signed-off-by: Yan Song <imeoer@linux.alibaba.com>

cache/not_nydus.go → cache/compression.go

@@ -8,18 +8,9 @@ import (
 
 	"github.com/containerd/containerd/content"
 	"github.com/moby/buildkit/cache/config"
-	"github.com/moby/buildkit/session"
-	"github.com/moby/buildkit/solver"
-	"github.com/moby/buildkit/util/compression"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-var validAnnotations = append(compression.EStargzAnnotations, containerdUncompressed)
-
 func needsForceCompression(ctx context.Context, cs content.Store, source ocispecs.Descriptor, refCfg config.RefConfig) bool {
 	return refCfg.Compression.Force
 }
-
-func PatchLayers(ctx context.Context, ref ImmutableRef, refCfg config.RefConfig, remote *solver.Remote, sg session.Group) (*solver.Remote, error) {
-	return remote, nil
-}

cache/nydus.go → cache/compression_nydus.go

@@ -14,7 +14,6 @@ import (
 	"github.com/containerd/containerd/errdefs"
 	"github.com/moby/buildkit/cache/config"
 	"github.com/moby/buildkit/session"
-	"github.com/moby/buildkit/solver"
 	"github.com/moby/buildkit/util/compression"
 	digest "github.com/opencontainers/go-digest"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
@@ -23,16 +22,32 @@ import (
 	nydusify "github.com/containerd/nydus-snapshotter/pkg/converter"
 )
 
-var validAnnotations = append(
-	compression.EStargzAnnotations, containerdUncompressed,
-	nydusify.LayerAnnotationNydusBlob, nydusify.LayerAnnotationNydusBootstrap, nydusify.LayerAnnotationNydusBlobIDs,
-)
+func init() {
+	additionalAnnotations = append(
+		additionalAnnotations,
+		nydusify.LayerAnnotationNydusBlob, nydusify.LayerAnnotationNydusBootstrap, nydusify.LayerAnnotationNydusBlobIDs,
+	)
+}
 
-// mergeNydus does two steps:
+// Nydus compression type can't be mixed with other compression types in the same image,
+// so if `source` is this kind of layer, but the target is other compression type, we
+// should do the forced compression.
+func needsForceCompression(ctx context.Context, cs content.Store, source ocispecs.Descriptor, refCfg config.RefConfig) bool {
+	if refCfg.Compression.Force {
+		return true
+	}
+	isNydusBlob, _ := compression.Nydus.Is(ctx, cs, source)
+	if refCfg.Compression.Type == compression.Nydus {
+		return !isNydusBlob
+	}
+	return isNydusBlob
+}
+
+// MergeNydus does two steps:
 // 1. Extracts nydus bootstrap from nydus format (nydus blob + nydus bootstrap) for each layer.
 // 2. Merge all nydus bootstraps into a final bootstrap (will as an extra layer).
 // The nydus bootstrap size is very small, so the merge operation is fast.
-func mergeNydus(ctx context.Context, ref ImmutableRef, comp compression.Config, s session.Group) (*ocispecs.Descriptor, error) {
+func MergeNydus(ctx context.Context, ref ImmutableRef, comp compression.Config, s session.Group) (*ocispecs.Descriptor, error) {
 	iref, ok := ref.(*immutableRef)
 	if !ok {
 		return nil, fmt.Errorf("unsupported ref")
@@ -131,34 +146,3 @@ func mergeNydus(ctx context.Context, ref ImmutableRef, comp compression.Config,
 
 	return &desc, nil
 }
-
-// Nydus compression type can't be mixed with other compression types in the same image,
-// so if `source` is this kind of layer, but the target is other compression type, we
-// should do the forced compression.
-func needsForceCompression(ctx context.Context, cs content.Store, source ocispecs.Descriptor, refCfg config.RefConfig) bool {
-	if refCfg.Compression.Force {
-		return true
-	}
-	isNydusBlob, _ := compression.Nydus.Is(ctx, cs, source)
-	if refCfg.Compression.Type == compression.Nydus {
-		return !isNydusBlob
-	}
-	return isNydusBlob
-}
-
-// PatchLayers appends an extra nydus bootstrap layer
-// to the manifest of nydus image, this layer represents the
-// whole metadata of filesystem view for the entire image.
-func PatchLayers(ctx context.Context, ref ImmutableRef, refCfg config.RefConfig, remote *solver.Remote, sg session.Group) (*solver.Remote, error) {
-	if refCfg.Compression.Type != compression.Nydus {
-		return remote, nil
-	}
-
-	desc, err := mergeNydus(ctx, ref, refCfg.Compression, sg)
-	if err != nil {
-		return nil, errors.Wrap(err, "merge nydus layer")
-	}
-	remote.Descriptors = append(remote.Descriptors, *desc)
-
-	return remote, nil
-}

cache/refs.go

@@ -36,6 +36,8 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+var additionalAnnotations = append(compression.EStargzAnnotations, containerdUncompressed)
+
 // Ref is a reference to cacheable objects.
 type Ref interface {
 	Mountable
@@ -878,7 +880,7 @@ func filterAnnotationsForSave(a map[string]string) (b map[string]string) {
 	if a == nil {
 		return nil
 	}
-	for _, k := range validAnnotations {
+	for _, k := range additionalAnnotations {
 		v, ok := a[k]
 		if !ok {
 			continue

exporter/containerimage/patch.go

@@ -0,0 +1,18 @@
+//go:build !nydus
+// +build !nydus
+
+package containerimage
+
+import (
+	"context"
+
+	"github.com/moby/buildkit/cache"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/solver"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func patchImageLayers(ctx context.Context, remote *solver.Remote, history []ocispecs.History, ref cache.ImmutableRef, opts *ImageCommitOpts, sg session.Group) (*solver.Remote, []ocispecs.History, error) {
+	remote, history = normalizeLayersAndHistory(ctx, remote, history, ref, opts.OCITypes)
+	return remote, history, nil
+}

exporter/containerimage/patch_nydus.go

@@ -0,0 +1,35 @@
+//go:build nydus
+// +build nydus
+
+package containerimage
+
+import (
+	"context"
+
+	"github.com/moby/buildkit/cache"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/solver"
+	"github.com/moby/buildkit/util/compression"
+	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+// patchImageLayers appends an extra nydus bootstrap layer
+// to the manifest of nydus image, normalizes layers and
+// history. The nydus bootstrap layer represents the whole
+// metadata of filesystem view for the entire image.
+func patchImageLayers(ctx context.Context, remote *solver.Remote, history []ocispecs.History, ref cache.ImmutableRef, opts *ImageCommitOpts, sg session.Group) (*solver.Remote, []ocispecs.History, error) {
+	if opts.RefCfg.Compression.Type != compression.Nydus {
+		remote, history = normalizeLayersAndHistory(ctx, remote, history, ref, opts.OCITypes)
+		return remote, history, nil
+	}
+
+	desc, err := cache.MergeNydus(ctx, ref, opts.RefCfg.Compression, sg)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "merge nydus layer")
+	}
+	remote.Descriptors = append(remote.Descriptors, *desc)
+
+	remote, history = normalizeLayersAndHistory(ctx, remote, history, ref, opts.OCITypes)
+	return remote, history, nil
+}

exporter/containerimage/writer.go

@@ -432,13 +432,11 @@ func (ic *ImageWriter) commitDistributionManifest(ctx context.Context, opts *Ima
 		return nil, nil, err
 	}
 
-	remote, err = cache.PatchLayers(ctx, ref, opts.RefCfg, remote, sg)
+	remote, history, err = patchImageLayers(ctx, remote, history, ref, opts, sg)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	remote, history = normalizeLayersAndHistory(ctx, remote, history, ref, opts.OCITypes)
-
 	config, err = patchImageConfig(config, remote.Descriptors, history, inlineCache, buildInfo, epoch)
 	if err != nil {
 		return nil, nil, err