controller: remove the controller interface

The controller interface is removed and the local controller is used for
only the initial build, invoke, and rebuilds.

Process control has been moved to the monitor.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

commands/debug/root.go

@@ -5,7 +5,7 @@ import (
 	"os"
 
 	"github.com/containerd/console"
-	"github.com/docker/buildx/controller"
+	"github.com/docker/buildx/controller/local"
 	controllerapi "github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/monitor"
 	"github.com/docker/buildx/util/cobrautil"
@@ -13,7 +13,6 @@ import (
 	"github.com/docker/cli/cli/command"
 	"github.com/moby/buildkit/util/progress/progressui"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
@@ -47,12 +46,8 @@ func RootCmd(dockerCli command.Cli, children ...DebuggableCmd) *cobra.Command {
 			}
 
 			ctx := context.TODO()
-			c := controller.NewController(ctx, dockerCli)
-			defer func() {
-				if err := c.Close(); err != nil {
-					logrus.Warnf("failed to close server connection %v", err)
-				}
-			}()
+			c := local.NewController(ctx, dockerCli)
+
 			con := console.Current()
 			if err := con.SetRaw(); err != nil {
 				return errors.Errorf("failed to configure terminal: %v", err)