@@ -14,6 +14,7 @@ import (

 	"github.com/docker/docker/pkg/stringid"

 	"github.com/pkg/errors"

 	"golang.org/x/sync/errgroup"

+	"google.golang.org/grpc"

 )

 // ImageComponent provides an interface for working with images

@@ -40,6 +41,13 @@ func NewBackend(components ImageComponent, builder Builder, fsCache *fscache.FSC

 	return &Backend{imageComponent: components, builder: builder, fsCache: fsCache, buildkit: buildkit}, nil

 }

+// RegisterGRPC registers buildkit controller to the grpc server.

+func (b *Backend) RegisterGRPC(s *grpc.Server) {

+	if b.buildkit != nil {

+		b.buildkit.RegisterGRPC(s)

+	}

+}

+

 // Build builds an image from a Source

 func (b *Backend) Build(ctx context.Context, config backend.BuildConfig) (string, error) {

 	options := config.Options

@@ -31,6 +31,7 @@ import (

 	"github.com/moby/buildkit/util/tracing"

 	"github.com/pkg/errors"

 	"golang.org/x/sync/errgroup"

+	"google.golang.org/grpc"

 	grpcmetadata "google.golang.org/grpc/metadata"

 )

@@ -104,6 +105,11 @@ func New(opt Opt) (*Builder, error) {

 	return b, nil

 }

+// RegisterGRPC registers controller to the grpc server.

+func (b *Builder) RegisterGRPC(s *grpc.Server) {

+	b.controller.Register(s)

+}

+

 // Cancel cancels a build using ID

 func (b *Builder) Cancel(ctx context.Context, id string) error {

 	b.mu.Lock()

@@ -21,6 +21,7 @@ import (

 	checkpointrouter "github.com/docker/docker/api/server/router/checkpoint"

 	"github.com/docker/docker/api/server/router/container"

 	distributionrouter "github.com/docker/docker/api/server/router/distribution"

+	grpcrouter "github.com/docker/docker/api/server/router/grpc"

 	"github.com/docker/docker/api/server/router/image"

 	"github.com/docker/docker/api/server/router/network"

 	pluginrouter "github.com/docker/docker/api/server/router/plugin"

@@ -481,6 +482,16 @@ func initRouter(opts routerOptions) {

 		distributionrouter.NewRouter(opts.daemon.ImageService()),

 	}

+	grpcBackends := []grpcrouter.Backend{}

+	for _, b := range []interface{}{opts.daemon, opts.buildBackend} {

+		if b, ok := b.(grpcrouter.Backend); ok {

+			grpcBackends = append(grpcBackends, b)

+		}

+	}

+	if len(grpcBackends) > 0 {

+		routers = append(routers, grpcrouter.NewRouter(grpcBackends...))

+	}

+

 	if opts.daemon.NetworkControllerEnabled() {

 		routers = append(routers, network.NewRouter(opts.daemon, opts.cluster))

 	}