monitor: Enable to exec into the container

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

controller/local/controller.go

@@ -3,12 +3,15 @@ package local
 import (
 	"context"
 	"io"
+	"sync/atomic"
 
 	"github.com/containerd/console"
 	"github.com/docker/buildx/build"
 	cbuild "github.com/docker/buildx/controller/build"
 	"github.com/docker/buildx/controller/control"
 	controllerapi "github.com/docker/buildx/controller/pb"
+	"github.com/docker/buildx/controller/processes"
+	"github.com/docker/buildx/util/ioset"
 	"github.com/docker/cli/cli/command"
 	"github.com/moby/buildkit/client"
 	"github.com/pkg/errors"
@@ -18,6 +21,7 @@ func NewLocalBuildxController(ctx context.Context, dockerCli command.Cli) contro
 	return &localController{
 		dockerCli: dockerCli,
 		ref:       "local",
+		processes: processes.NewManager(),
 	}
 }
 
@@ -25,9 +29,17 @@ type localController struct {
 	dockerCli command.Cli
 	ref       string
 	resultCtx *build.ResultContext
+	processes *processes.Manager
+
+	buildOnGoing atomic.Bool
 }
 
 func (b *localController) Build(ctx context.Context, options controllerapi.BuildOptions, in io.ReadCloser, w io.Writer, out console.File, progressMode string) (string, *client.SolveResponse, error) {
+	if !b.buildOnGoing.CompareAndSwap(false, true) {
+		return "", nil, errors.New("build ongoing")
+	}
+	defer b.buildOnGoing.Store(false)
+
 	resp, res, err := cbuild.RunBuild(ctx, b.dockerCli, options, in, progressMode, nil)
 	if err != nil {
 		return "", nil, err
@@ -36,38 +48,64 @@ func (b *localController) Build(ctx context.Context, options controllerapi.Build
 	return b.ref, resp, nil
 }
 
-func (b *localController) Invoke(ctx context.Context, ref string, cfg controllerapi.ContainerConfig, ioIn io.ReadCloser, ioOut io.WriteCloser, ioErr io.WriteCloser) error {
+func (b *localController) ListProcesses(ctx context.Context, ref string) (infos []*controllerapi.ProcessInfo, retErr error) {
+	if ref != b.ref {
+		return nil, errors.Errorf("unknown ref %q", ref)
+	}
+	return b.processes.ListProcesses(), nil
+}
+
+func (b *localController) DisconnectProcess(ctx context.Context, ref, pid string) error {
 	if ref != b.ref {
 		return errors.Errorf("unknown ref %q", ref)
 	}
-	if b.resultCtx == nil {
-		return errors.New("no build result is registered")
+	return b.processes.DeleteProcess(pid)
+}
+
+func (b *localController) cancelRunningProcesses() {
+	b.processes.CancelRunningProcesses()
+}
+
+func (b *localController) Invoke(ctx context.Context, ref string, pid string, cfg controllerapi.InvokeConfig, ioIn io.ReadCloser, ioOut io.WriteCloser, ioErr io.WriteCloser) error {
+	if ref != b.ref {
+		return errors.Errorf("unknown ref %q", ref)
 	}
-	ccfg := build.ContainerConfig{
-		ResultCtx:  b.resultCtx,
-		Entrypoint: cfg.Entrypoint,
-		Cmd:        cfg.Cmd,
-		Env:        cfg.Env,
-		Tty:        cfg.Tty,
-		Stdin:      ioIn,
-		Stdout:     ioOut,
-		Stderr:     ioErr,
+
+	proc, ok := b.processes.Get(pid)
+	if !ok {
+		// Start a new process.
+		if b.resultCtx == nil {
+			return errors.New("no build result is registered")
+		}
+		var err error
+		proc, err = b.processes.StartProcess(pid, b.resultCtx, &cfg)
+		if err != nil {
+			return err
+		}
 	}
-	if !cfg.NoUser {
-		ccfg.User = &cfg.User
+
+	// Attach containerIn to this process
+	ioCancelledCh := make(chan struct{})
+	proc.ForwardIO(&ioset.In{Stdin: ioIn, Stdout: ioOut, Stderr: ioErr}, func() { close(ioCancelledCh) })
+
+	select {
+	case <-ioCancelledCh:
+		return errors.Errorf("io cancelled")
+	case err := <-proc.Done():
+		return err
+	case <-ctx.Done():
+		return ctx.Err()
 	}
-	if !cfg.NoCwd {
-		ccfg.Cwd = &cfg.Cwd
-	}
-	return build.Invoke(ctx, ccfg)
 }
 
 func (b *localController) Kill(context.Context) error {
-	return nil // nop
+	b.cancelRunningProcesses()
+	return nil
 }
 
 func (b *localController) Close() error {
-	// TODO: cancel current build and invoke
+	b.cancelRunningProcesses()
+	// TODO: cancel ongoing builds?
 	return nil
 }
 
@@ -76,5 +114,6 @@ func (b *localController) List(ctx context.Context) (res []string, _ error) {
 }
 
 func (b *localController) Disconnect(ctx context.Context, key string) error {
-	return nil // nop
+	b.cancelRunningProcesses()
+	return nil
 }