add optional check that snapshotter supports the image platform when unpacking

Signed-off-by: Kathryn Baldauf <kabaldau@microsoft.com>

unpacker.go

@@ -31,6 +31,7 @@ import (
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/snapshots"
 	"github.com/opencontainers/go-digest"
 	"github.com/opencontainers/image-spec/identity"
@@ -93,6 +94,17 @@ func (u *unpacker) unpack(
 		return errors.Errorf("number of layers and diffIDs don't match: %d != %d", len(layers), len(diffIDs))
 	}
 
+	if u.config.CheckPlatformSupported {
+		imgPlatform := platforms.Normalize(ocispec.Platform{OS: i.OS, Architecture: i.Architecture})
+		snapshotterPlatformMatcher, err := u.c.GetSnapshotterSupportedPlatforms(ctx, u.snapshotter)
+		if err != nil {
+			return errors.Wrapf(err, "failed to find supported platforms for snapshotter %s", u.snapshotter)
+		}
+		if !snapshotterPlatformMatcher.Match(imgPlatform) {
+			return fmt.Errorf("snapshotter %s does not support platform %s for image %s", u.snapshotter, imgPlatform, config.Digest)
+		}
+	}
+
 	var (
 		sn = u.c.SnapshotService(u.snapshotter)
 		a  = u.c.DiffService()