Add shared content label to namespaces

Signed-off-by: Henry Wang <henwang@amazon.com>

metadata/content.go

@@ -398,7 +398,7 @@ func (cs *contentStore) Writer(ctx context.Context, opts ...content.WriterOpt) (
 				return nil
 			}
 
-			if cs.shared {
+			if cs.shared || isSharedContent(tx, wOpts.Desc.Digest) {
 				if st, err := cs.Store.Info(ctx, wOpts.Desc.Digest); err == nil {
 					// Ensure the expected size is the same, it is likely
 					// an error if the size is mismatched but the caller
@@ -706,6 +706,33 @@ func (cs *contentStore) checkAccess(ctx context.Context, dgst digest.Digest) err
 	})
 }
 
+func isSharedContent(tx *bolt.Tx, dgst digest.Digest) bool {
+	v1bkt := tx.Bucket(bucketKeyVersion)
+	if v1bkt == nil {
+		return false
+	}
+	// iterate through each namespace
+	v1c := v1bkt.Cursor()
+	for nk, _ := v1c.First(); nk != nil; nk, _ = v1c.Next() {
+		ns := string(nk)
+		lbkt := getNamespaceLabelsBucket(tx, ns)
+		if lbkt == nil {
+			continue
+		}
+		// iterate through each label
+		lbc := lbkt.Cursor()
+		for k, v := lbc.First(); k != nil; k, v = lbc.Next() {
+			if string(k) == labels.LabelSharedNamespace {
+				if string(v) == "true" && getBlobBucket(tx, ns, dgst) != nil {
+					return true
+				}
+				break
+			}
+		}
+	}
+	return false
+}
+
 func validateInfo(info *content.Info) error {
 	for k, v := range info.Labels {
 		if err := labels.Validate(k, v); err != nil {

metadata/content_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/containerd/containerd/content/local"
 	"github.com/containerd/containerd/content/testsuite"
 	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/labels"
 	"github.com/containerd/containerd/leases"
 	"github.com/containerd/containerd/namespaces"
 	digest "github.com/opencontainers/go-digest"
@@ -52,9 +53,18 @@ func createContentStore(ctx context.Context, root string, opts ...DBOpt) (contex
 		count uint64
 		name  = testsuite.Name(ctx)
 	)
-	wrap := func(ctx context.Context) (context.Context, func(context.Context) error, error) {
+	wrap := func(ctx context.Context, sharedNS bool) (context.Context, func(context.Context) error, error) {
 		n := atomic.AddUint64(&count, 1)
-		return namespaces.WithNamespace(ctx, fmt.Sprintf("%s-n%d", name, n)), func(context.Context) error {
+		ctx2 := namespaces.WithNamespace(ctx, fmt.Sprintf("%s-n%d", name, n))
+		if sharedNS {
+			db.Update(func(tx *bolt.Tx) error {
+				if ns, err := namespaces.NamespaceRequired(ctx2); err == nil {
+					return NewNamespaceStore(tx).SetLabel(ctx2, ns, labels.LabelSharedNamespace, "true")
+				}
+				return err
+			})
+		}
+		return ctx2, func(context.Context) error {
 			return nil
 		}, nil
 	}
@@ -78,6 +88,10 @@ func TestContent(t *testing.T) {
 		t, "metadata", createContentStoreWithPolicy([]DBOpt{
 			WithPolicyIsolated,
 		}...))
+	testsuite.ContentSharedNSIsolatedSuite(
+		t, "metadata", createContentStoreWithPolicy([]DBOpt{
+			WithPolicyIsolated,
+		}...))
 }
 
 func TestContentLeased(t *testing.T) {