overlaybd build

Signed-off-by: liulanzheng <[email protected]>

cache/blobs.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path"
 	"strconv"
 
 	"github.com/containerd/containerd/content"
@@ -123,7 +124,7 @@ func computeBlobChain(ctx context.Context, sr *immutableRef, createIfNeeded bool
 					lowerRef = sr.layerParent
 				}
 				var lower []mount.Mount
-				if lowerRef != nil {
+				if sr.cm.Snapshotter.Name() != "overlaybd" && lowerRef != nil {
 					m, err := lowerRef.Mount(ctx, true, s)
 					if err != nil {
 						return nil, err
@@ -146,7 +147,20 @@ func computeBlobChain(ctx context.Context, sr *immutableRef, createIfNeeded bool
 					upperRef = sr
 				}
 				var upper []mount.Mount
-				if upperRef != nil {
+				if sr.cm.Snapshotter.Name() == "overlaybd" {
+					snStat, err := sr.cm.Snapshotter.Stat(ctx, sr.getSnapshotID())
+					if err != nil {
+						return nil, err
+					}
+					fsPath := path.Dir(snStat.Labels[LabelLocalOverlayBDPath])
+					upper = []mount.Mount{
+						{
+							Source:  fsPath,
+							Type:    "bind",
+							Options: []string{"ro", "rbind"},
+						},
+					}
+				} else if upperRef != nil {
 					m, err := upperRef.Mount(ctx, true, s)
 					if err != nil {
 						return nil, err
@@ -234,6 +248,10 @@ func computeBlobChain(ctx context.Context, sr *immutableRef, createIfNeeded bool
 				if desc.Annotations == nil {
 					desc.Annotations = map[string]string{}
 				}
+				if sr.cm.Snapshotter.Name() == "overlaybd" {
+					desc.Annotations[labelKeyOverlayBDBlobDigest] = string(desc.Digest)
+					desc.Annotations[labelKeyOverlayBDBlobSize] = fmt.Sprintf("%d", desc.Size)
+				}
 				if finalize != nil {
 					a, err := finalize(ctx, sr.cm.ContentStore)
 					if err != nil {

cache/manager.go

@@ -14,6 +14,7 @@ import (
 	"github.com/containerd/containerd/filters"
 	"github.com/containerd/containerd/gc"
 	"github.com/containerd/containerd/leases"
+	"github.com/containerd/containerd/snapshots"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/moby/buildkit/cache/metadata"
 	"github.com/moby/buildkit/client"
@@ -611,6 +612,11 @@ func (cm *cacheManager) New(ctx context.Context, s ImmutableRef, sess session.Gr
 		}); rerr != nil {
 			return nil, rerr
 		}
+	} else if cm.Snapshotter.Name() == "overlaybd" && parent != nil {
+		rwLabels := make(map[string]string)
+		rwLabels["containerd.io/snapshot/overlaybd.writable"] = "dev"
+		logrus.Infof("Prepare writable dev")
+		err = cm.Snapshotter.Prepare(ctx, snapshotID, parentSnapshotID, snapshots.WithLabels(rwLabels))
 	} else {
 		err = cm.Snapshotter.Prepare(ctx, snapshotID, parentSnapshotID)
 	}

cache/refs.go

@@ -36,6 +36,15 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+const (
+	LabelLocalOverlayBDPath     = "containerd.io/snapshot/overlaybd.localcommitpath"
+	labelKeyOverlayBDBlobDigest = "containerd.io/snapshot/overlaybd/blob-digest"
+	labelKeyOverlayBDBlobSize   = "containerd.io/snapshot/overlaybd/blob-size"
+	labelKeyOverlayBDBlobFsType = "containerd.io/snapshot/overlaybd/blob-fs-type"
+)
+
+var overlaybdAnnotations = []string{labelKeyOverlayBDBlobFsType, labelKeyOverlayBDBlobSize, labelKeyOverlayBDBlobDigest}
+
 // Ref is a reference to cacheable objects.
 type Ref interface {
 	Mountable
@@ -881,7 +890,10 @@ func filterAnnotationsForSave(a map[string]string) (b map[string]string) {
 	if a == nil {
 		return nil
 	}
-	for _, k := range append(eStargzAnnotations, containerdUncompressed) {
+	annotations := eStargzAnnotations
+	annotations = append(annotations, containerdUncompressed)
+	annotations = append(annotations, overlaybdAnnotations...)
+	for _, k := range annotations {
 		v, ok := a[k]
 		if !ok {
 			continue
@@ -957,6 +969,10 @@ func (sr *immutableRef) Extract(ctx context.Context, s session.Group) (rerr erro
 			return err
 		}
 		return rerr
+	} else if sr.cm.Snapshotter.Name() == "overlaybd" {
+		if rerr = sr.prepareRemoteSnapshotsOverlaybdMode(ctx, s); rerr == nil {
+			return nil
+		}
 	}
 
 	return sr.unlazy(ctx, sr.descHandlers, sr.progress, s, true)
@@ -1073,6 +1089,60 @@ func (sr *immutableRef) prepareRemoteSnapshotsStargzMode(ctx context.Context, s
 	return err
 }
 
+func (sr *immutableRef) prepareRemoteSnapshotsOverlaybdMode(ctx context.Context, s session.Group) error {
+	_, err := sr.sizeG.Do(ctx, sr.ID()+"-prepare-remote-snapshot", func(ctx context.Context) (_ interface{}, rerr error) {
+		dhs := sr.descHandlers
+		for _, r := range sr.layerChain() {
+			r := r
+			snapshotID := r.getSnapshotID()
+			if _, err := r.cm.Snapshotter.Stat(ctx, snapshotID); err == nil {
+				continue
+			}
+
+			dh := dhs[digest.Digest(r.getBlob())]
+			if dh == nil {
+				// We cannot prepare remote snapshots without descHandler.
+				return nil, nil
+			}
+
+			defaultLabels := snapshots.FilterInheritedLabels(dh.SnapshotLabels)
+			if defaultLabels == nil {
+				defaultLabels = make(map[string]string)
+			}
+			defaultLabels["containerd.io/snapshot.ref"] = snapshotID
+
+			// Prepare remote snapshots
+			var (
+				key  = fmt.Sprintf("tmp-%s %s", identity.NewID(), r.getChainID())
+				opts = []snapshots.Opt{
+					snapshots.WithLabels(defaultLabels),
+				}
+			)
+			parentID := ""
+			if r.layerParent != nil {
+				parentID = r.layerParent.getSnapshotID()
+			}
+			if err := r.cm.Snapshotter.Prepare(ctx, key, parentID, opts...); err != nil {
+				if errdefs.IsAlreadyExists(err) {
+					// Check if the targeting snapshot ID has been prepared as
+					// a remote snapshot in the snapshotter.
+					_, err := r.cm.Snapshotter.Stat(ctx, snapshotID)
+					if err == nil { // usable as remote snapshot without unlazying.
+						// Try the next layer as well.
+						continue
+					}
+				}
+			}
+
+			// This layer and all upper layers cannot be prepared without unlazying.
+			break
+		}
+
+		return nil, nil
+	})
+	return err
+}
+
 func makeTmpLabelsStargzMode(labels map[string]string, s session.Group) (fields []string, res map[string]string) {
 	res = make(map[string]string)
 	// Append unique ID to labels for avoiding collision of labels among calls

test/Dockerfile

@@ -0,0 +1,2 @@
+FROM docker.io/overlaybd/redis:6.2.6_obd
+RUN dd if=/dev/urandom of=/opt/x bs=1M count=1

util/estargz/labels.go

@@ -19,6 +19,7 @@ func SnapshotLabels(ref string, descs []ocispecs.Descriptor, targetIndex int) ma
 		labels[k] = desc.Annotations[k]
 	}
 	labels["containerd.io/snapshot/remote/stargz.reference"] = ref
+	labels["containerd.io/snapshot/image-ref"] = ref
 	labels["containerd.io/snapshot/remote/stargz.digest"] = desc.Digest.String()
 	var (
 		layersKey = "containerd.io/snapshot/remote/stargz.layers"