daemon: access to distribution internals

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

daemon/daemon.go

@@ -922,6 +922,10 @@ func NewDaemon(config *config.Config, registryService registry.Service, containe
 	return d, nil
 }
 
+func (daemon *Daemon) DistributionServices() images.DistributionServices {
+	return daemon.imageService.DistributionServices()
+}
+
 func (daemon *Daemon) waitForStartupDone() {
 	<-daemon.startupDone
 }

daemon/images/service.go

@@ -3,9 +3,11 @@ package images // import "github.com/docker/docker/daemon/images"
 import (
 	"context"
 	"os"
+	"runtime"
 
 	"github.com/docker/docker/container"
 	daemonevents "github.com/docker/docker/daemon/events"
+	"github.com/docker/docker/distribution"
 	"github.com/docker/docker/distribution/metadata"
 	"github.com/docker/docker/distribution/xfer"
 	"github.com/docker/docker/image"
@@ -74,6 +76,24 @@ type ImageService struct {
 	uploadManager             *xfer.LayerUploadManager
 }
 
+type DistributionServices struct {
+	DownloadManager   distribution.RootFSDownloadManager
+	V2MetadataService metadata.V2MetadataService
+	LayerStore        layer.Store // TODO: lcow
+	ImageStore        image.Store
+	ReferenceStore    dockerreference.Store
+}
+
+func (i *ImageService) DistributionServices() DistributionServices {
+	return DistributionServices{
+		DownloadManager:   i.downloadManager,
+		V2MetadataService: metadata.NewV2MetadataService(i.distributionMetadataStore),
+		LayerStore:        i.layerStores[runtime.GOOS],
+		ImageStore:        i.imageStore,
+		ReferenceStore:    i.referenceStore,
+	}
+}
+
 // CountImages returns the number of images stored by ImageService
 // called from info.go
 func (i *ImageService) CountImages() int {

layer/layer_store.go

@@ -121,6 +121,10 @@ func newStoreFromGraphDriver(root string, driver graphdriver.Driver, os string)
 	return ls, nil
 }
 
+func (ls *layerStore) Driver() graphdriver.Driver {
+	return ls.driver
+}
+
 func (ls *layerStore) loadLayer(layer ChainID) (*roLayer, error) {
 	cl, ok := ls.layerMap[layer]
 	if ok {

layer/ro_layer.go

@@ -54,6 +54,10 @@ func (rl *roLayer) TarStreamFrom(parent ChainID) (io.ReadCloser, error) {
 	return rl.layerStore.driver.Diff(rl.cacheID, parentCacheID)
 }
 
+func (rl *roLayer) CacheID() string {
+	return rl.cacheID
+}
+
 func (rl *roLayer) ChainID() ChainID {
 	return rl.chainID
 }