controller: refactor progress api

Refactor the progress printer creation to the caller-side of the
controller api. Then, instead of passing around status channels (and
progressMode strings), we can simply pass around the higher level
interface progress.Writer.

This has a couple of benefits:
- A simplified interface to the controller
- Allows us to correctly extract warnings out of the controller, so that
  they can be displayed correctly from the client side.

Some extra work is required to make sure that we can pass a
progress.Printer into the debug monitor. If we want to keep it
persistent, then we need a way to temporarily suspend output from it,
otherwise it will continue printing as the monitor is prompting for
input from the user, and forwarding output from debug containers.

To handle this, we add two methods to the printer, `Pause` and
`Unpause`. `Pause` acts similarly to `Wait`, closing the printer, and
cleanly shutting down the display - however, the printer does not
terminate, and can later be resumed by a call to `Unpause`. This
provides a neater interface to the caller, instead of needing to
continually reconstruct printers for every single time we want to
produce progress output.

Signed-off-by: Justin Chadwell <me@jedevc.com>

commands/build.go

@@ -1,6 +1,7 @@
 package commands
 
 import (
+	"bytes"
 	"context"
 	"encoding/base64"
 	"encoding/csv"
@@ -15,6 +16,7 @@ import (
 
 	"github.com/containerd/console"
 	"github.com/docker/buildx/build"
+	"github.com/docker/buildx/builder"
 	"github.com/docker/buildx/controller"
 	cbuild "github.com/docker/buildx/controller/build"
 	"github.com/docker/buildx/controller/control"
@@ -35,8 +37,11 @@ import (
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/exporter/containerimage/exptypes"
+	"github.com/moby/buildkit/solver/errdefs"
 	"github.com/moby/buildkit/util/appcontext"
 	"github.com/moby/buildkit/util/grpcerrors"
+	"github.com/moby/buildkit/util/progress/progressui"
+	"github.com/morikuni/aec"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -202,18 +207,44 @@ func runBuild(dockerCli command.Cli, options buildOptions) (err error) {
 		}
 	}
 
+	contextPathHash := options.contextPath
+	if absContextPath, err := filepath.Abs(contextPathHash); err == nil {
+		contextPathHash = absContextPath
+	}
+	b, err := builder.New(dockerCli,
+		builder.WithName(options.builder),
+		builder.WithContextPathHash(contextPathHash),
+	)
+	if err != nil {
+		return err
+	}
+
+	ctx2, cancel := context.WithCancel(context.TODO())
+	defer cancel()
 	progressMode, err := options.toProgress()
 	if err != nil {
 		return err
 	}
+	printer, err := progress.NewPrinter(ctx2, os.Stderr, os.Stderr, progressMode, progressui.WithDesc(
+		fmt.Sprintf("building with %q instance using %s driver", b.Name, b.Driver),
+		fmt.Sprintf("%s:%s", b.Driver, b.Name),
+	))
+	if err != nil {
+		return err
+	}
 
 	var resp *client.SolveResponse
 	var retErr error
 	if isExperimental() {
-		resp, retErr = runControllerBuild(ctx, dockerCli, options, progressMode)
+		resp, retErr = runControllerBuild(ctx, dockerCli, options, printer)
 	} else {
-		resp, retErr = runBasicBuild(ctx, dockerCli, options, progressMode)
+		resp, retErr = runBasicBuild(ctx, dockerCli, options, printer)
 	}
+
+	if err := printer.Wait(); retErr == nil {
+		retErr = err
+	}
+	printWarnings(os.Stderr, printer.Warnings(), progressMode)
 	if retErr != nil {
 		return retErr
 	}
@@ -232,17 +263,17 @@ func runBuild(dockerCli command.Cli, options buildOptions) (err error) {
 	return nil
 }
 
-func runBasicBuild(ctx context.Context, dockerCli command.Cli, options buildOptions, progressMode string) (*client.SolveResponse, error) {
+func runBasicBuild(ctx context.Context, dockerCli command.Cli, options buildOptions, printer *progress.Printer) (*client.SolveResponse, error) {
 	opts, err := options.toControllerOptions()
 	if err != nil {
 		return nil, err
 	}
 
-	resp, _, err := cbuild.RunBuild(ctx, dockerCli, *opts, os.Stdin, progressMode, nil, false)
+	resp, _, err := cbuild.RunBuild(ctx, dockerCli, *opts, os.Stdin, printer, false)
 	return resp, err
 }
 
-func runControllerBuild(ctx context.Context, dockerCli command.Cli, options buildOptions, progressMode string) (*client.SolveResponse, error) {
+func runControllerBuild(ctx context.Context, dockerCli command.Cli, options buildOptions, printer *progress.Printer) (*client.SolveResponse, error) {
 	if options.invoke != nil && (options.dockerfileName == "-" || options.contextPath == "-") {
 		// stdin must be usable for monitor
 		return nil, errors.Errorf("Dockerfile or context from stdin is not supported with invoke")
@@ -284,7 +315,7 @@ func runControllerBuild(ctx context.Context, dockerCli command.Cli, options buil
 			return nil
 		})
 
-		ref, resp, err = c.Build(ctx, *opts, pr, os.Stdout, os.Stderr, progressMode)
+		ref, resp, err = c.Build(ctx, *opts, pr, printer)
 		if err != nil {
 			var be *controllererrors.BuildError
 			if errors.As(err, &be) {
@@ -318,7 +349,7 @@ func runControllerBuild(ctx context.Context, dockerCli command.Cli, options buil
 			}
 			return nil, errors.Errorf("failed to configure terminal: %v", err)
 		}
-		err = monitor.RunMonitor(ctx, ref, opts, options.invoke.InvokeConfig, c, progressMode, pr2, os.Stdout, os.Stderr)
+		err = monitor.RunMonitor(ctx, ref, opts, options.invoke.InvokeConfig, c, pr2, os.Stdout, os.Stderr, printer)
 		con.Reset()
 		if err := pw2.Close(); err != nil {
 			logrus.Debug("failed to close monitor stdin pipe reader")
@@ -869,3 +900,43 @@ func resolvePaths(options *controllerapi.BuildOptions) (_ *controllerapi.BuildOp
 
 	return options, nil
 }
+
+func printWarnings(w io.Writer, warnings []client.VertexWarning, mode string) {
+	if len(warnings) == 0 || mode == progress.PrinterModeQuiet {
+		return
+	}
+	fmt.Fprintf(w, "\n ")
+	sb := &bytes.Buffer{}
+	if len(warnings) == 1 {
+		fmt.Fprintf(sb, "1 warning found")
+	} else {
+		fmt.Fprintf(sb, "%d warnings found", len(warnings))
+	}
+	if logrus.GetLevel() < logrus.DebugLevel {
+		fmt.Fprintf(sb, " (use --debug to expand)")
+	}
+	fmt.Fprintf(sb, ":\n")
+	fmt.Fprint(w, aec.Apply(sb.String(), aec.YellowF))
+
+	for _, warn := range warnings {
+		fmt.Fprintf(w, " - %s\n", warn.Short)
+		if logrus.GetLevel() < logrus.DebugLevel {
+			continue
+		}
+		for _, d := range warn.Detail {
+			fmt.Fprintf(w, "%s\n", d)
+		}
+		if warn.URL != "" {
+			fmt.Fprintf(w, "More info: %s\n", warn.URL)
+		}
+		if warn.SourceInfo != nil && warn.Range != nil {
+			src := errdefs.Source{
+				Info:   warn.SourceInfo,
+				Ranges: warn.Range,
+			}
+			src.Print(w)
+		}
+		fmt.Fprintf(w, "\n")
+
+	}
+}

commands/debug-shell.go

@@ -10,6 +10,7 @@ import (
 	"github.com/docker/buildx/controller/control"
 	controllerapi "github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/monitor"
+	"github.com/docker/buildx/util/progress"
 	"github.com/docker/cli/cli/command"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -18,7 +19,7 @@ import (
 
 func debugShellCmd(dockerCli command.Cli) *cobra.Command {
 	var options control.ControlOptions
-	var progress string
+	var progressMode string
 
 	cmd := &cobra.Command{
 		Use:   "debug-shell",
@@ -38,9 +39,15 @@ func debugShellCmd(dockerCli command.Cli) *cobra.Command {
 			if err := con.SetRaw(); err != nil {
 				return errors.Errorf("failed to configure terminal: %v", err)
 			}
+
+			printer, err := progress.NewPrinter(context.TODO(), os.Stderr, os.Stderr, progressMode)
+			if err != nil {
+				return err
+			}
+
 			err = monitor.RunMonitor(ctx, "", nil, controllerapi.InvokeConfig{
 				Tty: true,
-			}, c, progress, os.Stdin, os.Stdout, os.Stderr)
+			}, c, os.Stdin, os.Stdout, os.Stderr, printer)
 			con.Reset()
 			return err
 		},
@@ -51,7 +58,7 @@ func debugShellCmd(dockerCli command.Cli) *cobra.Command {
 	flags.StringVar(&options.Root, "root", "", "Specify root directory of server to connect [experimental]")
 	flags.BoolVar(&options.Detach, "detach", runtime.GOOS == "linux", "Detach buildx server (supported only on linux) [experimental]")
 	flags.StringVar(&options.ServerConfig, "server-config", "", "Specify buildx server config file (used only when launching new server) [experimental]")
-	flags.StringVar(&progress, "progress", "auto", `Set type of progress output ("auto", "plain", "tty"). Use plain to show container output`)
+	flags.StringVar(&progressMode, "progress", "auto", `Set type of progress output ("auto", "plain", "tty"). Use plain to show container output`)
 
 	return cmd
 }

controller/build/build.go

@@ -1,12 +1,10 @@
 package build
 
 import (
-	"bytes"
 	"context"
 	"encoding/base64"
 	"encoding/csv"
 	"encoding/json"
-	"fmt"
 	"io"
 	"os"
 	"path/filepath"
@@ -30,12 +28,8 @@ import (
 	"github.com/docker/go-units"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/session/auth/authprovider"
-	"github.com/moby/buildkit/solver/errdefs"
 	"github.com/moby/buildkit/util/grpcerrors"
-	"github.com/moby/buildkit/util/progress/progressui"
-	"github.com/morikuni/aec"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"google.golang.org/grpc/codes"
 )
 
@@ -46,7 +40,7 @@ const defaultTargetName = "default"
 // NOTE: When an error happens during the build and this function acquires the debuggable *build.ResultContext,
 // this function returns it in addition to the error (i.e. it does "return nil, res, err"). The caller can
 // inspect the result and debug the cause of that error.
-func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.BuildOptions, inStream io.Reader, progressMode string, statusChan chan *client.SolveStatus, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
+func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.BuildOptions, inStream io.Reader, progress progress.Writer, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
 	if in.NoCache && len(in.NoCacheFilter) > 0 {
 		return nil, nil, errors.Errorf("--no-cache and --no-cache-filter cannot currently be used together")
 	}
@@ -164,6 +158,7 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.Build
 		contextPathHash = in.ContextPath
 	}
 
+	// TODO: this should not be loaded this side of the controller api
 	b, err := builder.New(dockerCli,
 		builder.WithName(in.Builder),
 		builder.WithContextPathHash(contextPathHash),
@@ -179,7 +174,7 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.Build
 		return nil, nil, err
 	}
 
-	resp, res, err := buildTargets(ctx, dockerCli, b.NodeGroup, nodes, map[string]build.Options{defaultTargetName: opts}, progressMode, in.MetadataFile, statusChan, generateResult)
+	resp, res, err := buildTargets(ctx, dockerCli, b.NodeGroup, nodes, map[string]build.Options{defaultTargetName: opts}, progress, in.MetadataFile, generateResult)
 	err = wrapBuildError(err, false)
 	if err != nil {
 		// NOTE: buildTargets can return *build.ResultContext even on error.
@@ -193,24 +188,14 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.Build
 // NOTE: When an error happens during the build and this function acquires the debuggable *build.ResultContext,
 // this function returns it in addition to the error (i.e. it does "return nil, res, err"). The caller can
 // inspect the result and debug the cause of that error.
-func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGroup, nodes []builder.Node, opts map[string]build.Options, progressMode string, metadataFile string, statusChan chan *client.SolveStatus, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
+func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGroup, nodes []builder.Node, opts map[string]build.Options, progress progress.Writer, metadataFile string, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
-	ctx2, cancel := context.WithCancel(context.TODO())
-	defer cancel()
-
-	printer, err := progress.NewPrinter(ctx2, os.Stderr, os.Stderr, progressMode, progressui.WithDesc(
-		fmt.Sprintf("building with %q instance using %s driver", ng.Name, ng.Driver),
-		fmt.Sprintf("%s:%s", ng.Driver, ng.Name),
-	))
-	if err != nil {
-		return nil, nil, err
-	}
-
 	var res *build.ResultContext
 	var resp map[string]*client.SolveResponse
+	var err error
 	if generateResult {
 		var mu sync.Mutex
 		var idx int
-		resp, err = build.BuildWithResultHandler(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress.Tee(printer, statusChan), func(driverIndex int, gotRes *build.ResultContext) {
+		resp, err = build.BuildWithResultHandler(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress, func(driverIndex int, gotRes *build.ResultContext) {
 			mu.Lock()
 			defer mu.Unlock()
 			if res == nil || driverIndex < idx {
@@ -218,11 +203,7 @@ func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGrou
 			}
 		})
 	} else {
-		resp, err = build.Build(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress.Tee(printer, statusChan))
+		resp, err = build.Build(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress)
-	}
-	err1 := printer.Wait()
-	if err == nil {
-		err = err1
 	}
 	if err != nil {
 		return nil, res, err
@@ -234,8 +215,6 @@ func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGrou
 		}
 	}
 
-	printWarnings(os.Stderr, printer.Warnings(), progressMode)
-
 	for k := range resp {
 		if opts[k].PrintFunc != nil {
 			if err := printResult(opts[k].PrintFunc, resp[k].ExporterResponse); err != nil {
@@ -247,46 +226,6 @@ func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGrou
 	return resp[defaultTargetName], res, err
 }
 
-func printWarnings(w io.Writer, warnings []client.VertexWarning, mode string) {
-	if len(warnings) == 0 || mode == progress.PrinterModeQuiet {
-		return
-	}
-	fmt.Fprintf(w, "\n ")
-	sb := &bytes.Buffer{}
-	if len(warnings) == 1 {
-		fmt.Fprintf(sb, "1 warning found")
-	} else {
-		fmt.Fprintf(sb, "%d warnings found", len(warnings))
-	}
-	if logrus.GetLevel() < logrus.DebugLevel {
-		fmt.Fprintf(sb, " (use --debug to expand)")
-	}
-	fmt.Fprintf(sb, ":\n")
-	fmt.Fprint(w, aec.Apply(sb.String(), aec.YellowF))
-
-	for _, warn := range warnings {
-		fmt.Fprintf(w, " - %s\n", warn.Short)
-		if logrus.GetLevel() < logrus.DebugLevel {
-			continue
-		}
-		for _, d := range warn.Detail {
-			fmt.Fprintf(w, "%s\n", d)
-		}
-		if warn.URL != "" {
-			fmt.Fprintf(w, "More info: %s\n", warn.URL)
-		}
-		if warn.SourceInfo != nil && warn.Range != nil {
-			src := errdefs.Source{
-				Info:   warn.SourceInfo,
-				Ranges: warn.Range,
-			}
-			src.Print(w)
-		}
-		fmt.Fprintf(w, "\n")
-
-	}
-}
-
 func parsePrintFunc(str string) (*build.PrintFunc, error) {
 	if str == "" {
 		return nil, nil

controller/control/controller.go

@@ -4,13 +4,13 @@ import (
 	"context"
 	"io"
 
-	"github.com/containerd/console"
 	controllerapi "github.com/docker/buildx/controller/pb"
+	"github.com/docker/buildx/util/progress"
 	"github.com/moby/buildkit/client"
 )
 
 type BuildxController interface {
-	Build(ctx context.Context, options controllerapi.BuildOptions, in io.ReadCloser, w io.Writer, out console.File, progressMode string) (ref string, resp *client.SolveResponse, err error)
+	Build(ctx context.Context, options controllerapi.BuildOptions, in io.ReadCloser, progress progress.Writer) (ref string, resp *client.SolveResponse, err error)
 	// Invoke starts an IO session into the specified process.
 	// If pid doesn't matche to any running processes, it starts a new process with the specified config.
 	// If there is no container running or InvokeConfig.Rollback is speicfied, the process will start in a newly created container.

controller/local/controller.go

@@ -5,7 +5,6 @@ import (
 	"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"
@@ -13,6 +12,7 @@ import (
 	controllerapi "github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/controller/processes"
 	"github.com/docker/buildx/util/ioset"
+	"github.com/docker/buildx/util/progress"
 	"github.com/docker/cli/cli/command"
 	"github.com/moby/buildkit/client"
 	"github.com/pkg/errors"
@@ -42,13 +42,13 @@ type localController struct {
 	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) {
+func (b *localController) Build(ctx context.Context, options controllerapi.BuildOptions, in io.ReadCloser, progress progress.Writer) (string, *client.SolveResponse, error) {
 	if !b.buildOnGoing.CompareAndSwap(false, true) {
 		return "", nil, errors.New("build ongoing")
 	}
 	defer b.buildOnGoing.Store(false)
 
-	resp, res, buildErr := cbuild.RunBuild(ctx, b.dockerCli, options, in, progressMode, nil, true)
+	resp, res, buildErr := cbuild.RunBuild(ctx, b.dockerCli, options, in, progress, true)
 	// NOTE: RunBuild can return *build.ResultContext even on error.
 	if res != nil {
 		b.buildConfig = buildConfig{

controller/pb/progress.go

@@ -1,10 +1,30 @@
 package pb
 
 import (
+	"github.com/docker/buildx/util/progress"
 	control "github.com/moby/buildkit/api/services/control"
 	"github.com/moby/buildkit/client"
+	"github.com/opencontainers/go-digest"
 )
 
+type writer struct {
+	ch chan<- *StatusResponse
+}
+
+func NewProgressWriter(ch chan<- *StatusResponse) progress.Writer {
+	return &writer{ch: ch}
+}
+
+func (w *writer) Write(status *client.SolveStatus) {
+	w.ch <- ToControlStatus(status)
+}
+
+func (w *writer) ValidateLogSource(digest.Digest, interface{}) bool {
+	return true
+}
+
+func (w *writer) ClearLogSource(interface{}) {}
+
 func ToControlStatus(s *client.SolveStatus) *StatusResponse {
 	resp := StatusResponse{}
 	for _, v := range s.Vertexes {

controller/remote/client.go

@@ -6,7 +6,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/containerd/console"
 	"github.com/containerd/containerd/defaults"
 	"github.com/containerd/containerd/pkg/dialer"
 	"github.com/docker/buildx/controller/pb"
@@ -114,14 +113,9 @@ func (c *Client) Inspect(ctx context.Context, ref string) (*pb.InspectResponse,
 	return c.client().Inspect(ctx, &pb.InspectRequest{Ref: ref})
 }
 
-func (c *Client) Build(ctx context.Context, options pb.BuildOptions, in io.ReadCloser, w io.Writer, out console.File, progressMode string) (string, *client.SolveResponse, error) {
+func (c *Client) Build(ctx context.Context, options pb.BuildOptions, in io.ReadCloser, progress progress.Writer) (string, *client.SolveResponse, error) {
 	ref := identity.NewID()
-	pw, err := progress.NewPrinter(context.TODO(), w, out, progressMode)
-	if err != nil {
-		return "", nil, err
-	}
 	statusChan := make(chan *client.SolveStatus)
-	statusDone := make(chan struct{})
 	eg, egCtx := errgroup.WithContext(ctx)
 	var resp *client.SolveResponse
 	eg.Go(func() error {
@@ -131,17 +125,12 @@ func (c *Client) Build(ctx context.Context, options pb.BuildOptions, in io.ReadC
 		return err
 	})
 	eg.Go(func() error {
-		defer close(statusDone)
 		for s := range statusChan {
 			st := s
-			pw.Write(st)
+			progress.Write(st)
 		}
 		return nil
 	})
-	eg.Go(func() error {
-		<-statusDone
-		return pw.Wait()
-	})
 	return ref, resp, eg.Wait()
 }
 

controller/remote/controller.go

@@ -21,6 +21,7 @@ import (
 	"github.com/docker/buildx/controller/control"
 	controllerapi "github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/util/confutil"
+	"github.com/docker/buildx/util/progress"
 	"github.com/docker/buildx/version"
 	"github.com/docker/cli/cli/command"
 	"github.com/moby/buildkit/client"
@@ -142,8 +143,8 @@ func serveCmd(dockerCli command.Cli) *cobra.Command {
 			}()
 
 			// prepare server
-			b := NewServer(func(ctx context.Context, options *controllerapi.BuildOptions, stdin io.Reader, statusChan chan *client.SolveStatus) (*client.SolveResponse, *build.ResultContext, error) {
+			b := NewServer(func(ctx context.Context, options *controllerapi.BuildOptions, stdin io.Reader, progress progress.Writer) (*client.SolveResponse, *build.ResultContext, error) {
-				return cbuild.RunBuild(ctx, dockerCli, *options, stdin, "quiet", statusChan, true)
+				return cbuild.RunBuild(ctx, dockerCli, *options, stdin, progress, true)
 			})
 			defer b.Close()
 

controller/remote/server.go

@@ -12,13 +12,14 @@ import (
 	"github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/controller/processes"
 	"github.com/docker/buildx/util/ioset"
+	"github.com/docker/buildx/util/progress"
 	"github.com/docker/buildx/version"
 	"github.com/moby/buildkit/client"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 )
 
-type BuildFunc func(ctx context.Context, options *pb.BuildOptions, stdin io.Reader, statusChan chan *client.SolveStatus) (resp *client.SolveResponse, res *build.ResultContext, err error)
+type BuildFunc func(ctx context.Context, options *pb.BuildOptions, stdin io.Reader, progress progress.Writer) (resp *client.SolveResponse, res *build.ResultContext, err error)
 
 func NewServer(buildFunc BuildFunc) *Server {
 	return &Server{
@@ -34,7 +35,7 @@ type Server struct {
 
 type session struct {
 	buildOnGoing atomic.Bool
-	statusChan   chan *client.SolveStatus
+	statusChan   chan *pb.StatusResponse
 	cancelBuild  func()
 	buildOptions *pb.BuildOptions
 	inputPipe    *io.PipeWriter
@@ -176,8 +177,9 @@ func (m *Server) Build(ctx context.Context, req *pb.BuildRequest) (*pb.BuildResp
 		s = &session{}
 		s.buildOnGoing.Store(true)
 	}
+
 	s.processes = processes.NewManager()
-	statusChan := make(chan *client.SolveStatus)
+	statusChan := make(chan *pb.StatusResponse)
 	s.statusChan = statusChan
 	inR, inW := io.Pipe()
 	defer inR.Close()
@@ -195,10 +197,12 @@ func (m *Server) Build(ctx context.Context, req *pb.BuildRequest) (*pb.BuildResp
 		m.sessionMu.Unlock()
 	}()
 
+	pw := pb.NewProgressWriter(statusChan)
+
 	// Build the specified request
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
-	resp, res, buildErr := m.buildFunc(ctx, req.Options, inR, statusChan)
+	resp, res, buildErr := m.buildFunc(ctx, req.Options, inR, pw)
 	m.sessionMu.Lock()
 	if s, ok := m.session[ref]; ok {
 		// NOTE: buildFunc can return *build.ResultContext even on error (e.g. when it's implemented using (github.com/docker/buildx/controller/build).RunBuild).
@@ -236,7 +240,7 @@ func (m *Server) Status(req *pb.StatusRequest, stream pb.Controller_StatusServer
 	}
 
 	// Wait and get status channel prepared by Build()
-	var statusChan <-chan *client.SolveStatus
+	var statusChan <-chan *pb.StatusResponse
 	for {
 		// TODO: timeout?
 		m.sessionMu.Lock()
@@ -255,7 +259,7 @@ func (m *Server) Status(req *pb.StatusRequest, stream pb.Controller_StatusServer
 		if ss == nil {
 			break
 		}
-		if err := stream.Send(pb.ToControlStatus(ss)); err != nil {
+		if err := stream.Send(ss); err != nil {
 			return err
 		}
 	}

monitor/monitor.go

@@ -15,6 +15,7 @@ import (
 	controllererrors "github.com/docker/buildx/controller/errdefs"
 	controllerapi "github.com/docker/buildx/controller/pb"
 	"github.com/docker/buildx/util/ioset"
+	"github.com/docker/buildx/util/progress"
 	"github.com/moby/buildkit/identity"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -36,12 +37,18 @@ Available commands are:
 `
 
 // RunMonitor provides an interactive session for running and managing containers via specified IO.
-func RunMonitor(ctx context.Context, curRef string, options *controllerapi.BuildOptions, invokeConfig controllerapi.InvokeConfig, c control.BuildxController, progressMode string, stdin io.ReadCloser, stdout io.WriteCloser, stderr console.File) error {
+func RunMonitor(ctx context.Context, curRef string, options *controllerapi.BuildOptions, invokeConfig controllerapi.InvokeConfig, c control.BuildxController, stdin io.ReadCloser, stdout io.WriteCloser, stderr console.File, progress *progress.Printer) error {
 	defer func() {
 		if err := c.Disconnect(ctx, curRef); err != nil {
 			logrus.Warnf("disconnect error: %v", err)
 		}
 	}()
+
+	if err := progress.Pause(); err != nil {
+		return err
+	}
+	defer progress.Unpause()
+
 	monitorIn, monitorOut := ioset.Pipe()
 	defer func() {
 		monitorIn.Close()
@@ -145,7 +152,9 @@ func RunMonitor(ctx context.Context, curRef string, options *controllerapi.Build
 						}
 					}
 					var resultUpdated bool
-					ref, _, err := c.Build(ctx, *bo, nil, stdout, stderr, progressMode) // TODO: support stdin, hold build ref
+					progress.Unpause()
+					ref, _, err := c.Build(ctx, *bo, nil, progress) // TODO: support stdin, hold build ref
+					progress.Pause()
 					if err != nil {
 						var be *controllererrors.BuildError
 						if errors.As(err, &be) {

util/progress/printer.go

@@ -24,7 +24,11 @@ const (
 
 type Printer struct {
 	status chan *client.SolveStatus
-	done         <-chan struct{}
+
+	ready  chan struct{}
+	done   chan struct{}
+	paused chan struct{}
+
 	err          error
 	warnings     []client.VertexWarning
 	logMu        sync.Mutex
@@ -37,6 +41,16 @@ func (p *Printer) Wait() error {
 	return p.err
 }
 
+func (p *Printer) Pause() error {
+	p.paused = make(chan struct{})
+	return p.Wait()
+}
+
+func (p *Printer) Unpause() {
+	close(p.paused)
+	<-p.ready
+}
+
 func (p *Printer) Write(s *client.SolveStatus) {
 	p.status <- s
 }
@@ -71,15 +85,6 @@ func (p *Printer) ClearLogSource(v interface{}) {
 }
 
 func NewPrinter(ctx context.Context, w io.Writer, out console.File, mode string, solveStatusOpt ...progressui.DisplaySolveStatusOpt) (*Printer, error) {
-	statusCh := make(chan *client.SolveStatus)
-	doneCh := make(chan struct{})
-
-	pw := &Printer{
-		status:       statusCh,
-		done:         doneCh,
-		logSourceMap: map[digest.Digest]interface{}{},
-	}
-
 	if v := os.Getenv("BUILDKIT_PROGRESS"); v != "" && mode == PrinterModeAuto {
 		mode = v
 	}
@@ -98,12 +103,35 @@ func NewPrinter(ctx context.Context, w io.Writer, out console.File, mode string,
 		}
 	}
 
+	pw := &Printer{
+		ready: make(chan struct{}),
+	}
 	go func() {
+		for {
+			pw.status = make(chan *client.SolveStatus)
+			pw.done = make(chan struct{})
+
+			pw.logMu.Lock()
+			pw.logSourceMap = map[digest.Digest]interface{}{}
+			pw.logMu.Unlock()
+
+			close(pw.ready)
+
 			resumeLogs := logutil.Pause(logrus.StandardLogger())
 			// not using shared context to not disrupt display but let is finish reporting errors
-		pw.warnings, pw.err = progressui.DisplaySolveStatus(ctx, c, w, statusCh, solveStatusOpt...)
+			pw.warnings, pw.err = progressui.DisplaySolveStatus(ctx, c, w, pw.status, solveStatusOpt...)
 			resumeLogs()
-		close(doneCh)
+			close(pw.done)
+
+			if pw.paused == nil {
+				break
+			}
+
+			pw.ready = make(chan struct{})
+			<-pw.paused
+			pw.paused = nil
+		}
 	}()
+	<-pw.ready
 	return pw, nil
 }