build: remove --stream

--stream was always experimental and this patch removes the functionality.

Users should enable BuildKit with DOCKER_BUILDKIT=1

Signed-off-by: Tibor Vass <tibor@docker.com>

Author: Tibor Vass

cli/command/image/build.go

@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"net"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -33,7 +32,6 @@ import (
 	"github.com/docker/docker/pkg/urlutil"
 	units "github.com/docker/go-units"
 	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
@@ -165,9 +163,7 @@ func NewBuildCommand(dockerCli command.Cli) *cobra.Command {
 	flags.SetAnnotation("squash", "version", []string{"1.25"})
 
 	flags.BoolVar(&options.stream, "stream", false, "Stream attaches to server to negotiate build context")
-	flags.SetAnnotation("stream", "experimental", nil)
-	flags.SetAnnotation("stream", "version", []string{"1.31"})
-	flags.SetAnnotation("stream", "no-buildkit", nil)
+	flags.MarkHidden("stream")
 
 	flags.StringVar(&options.progress, "progress", "auto", "Set type of progress output (auto, plain, tty). Use plain to show container output")
 	flags.SetAnnotation("progress", "buildkit", nil)
@@ -224,8 +220,8 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 		remote        string
 	)
 
-	if options.compress && options.stream {
-		return errors.New("--compress conflicts with --stream options")
+	if options.stream {
+		return errors.New("Experimental flag --stream was removed, enable BuildKit instead with DOCKER_BUILDKIT=1")
 	}
 
 	if options.dockerfileFromStdin() {
@@ -284,7 +280,7 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 	}
 
 	// read from a directory into tar archive
-	if buildCtx == nil && !options.stream {
+	if buildCtx == nil {
 		excludes, err := build.ReadDockerignore(contextDir)
 		if err != nil {
 			return err
@@ -315,16 +311,6 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 		}
 	}
 
-	// if streaming and Dockerfile was not from stdin then read from file
-	// to the same reader that is usually stdin
-	if options.stream && dockerfileCtx == nil {
-		dockerfileCtx, err = os.Open(relDockerfile)
-		if err != nil {
-			return errors.Wrapf(err, "failed to open %s", relDockerfile)
-		}
-		defer dockerfileCtx.Close()
-	}
-
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -367,38 +353,11 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 		buildCtx = dockerfileCtx
 	}
 
-	s, err := trySession(dockerCli, contextDir, true)
-	if err != nil {
-		return err
-	}
-
 	var body io.Reader
-	if buildCtx != nil && !options.stream {
+	if buildCtx != nil {
 		body = progress.NewProgressReader(buildCtx, progressOutput, 0, "", "Sending build context to Docker daemon")
 	}
 
-	// add context stream to the session
-	if options.stream && s != nil {
-		syncDone := make(chan error) // used to signal first progress reporting completed.
-		// progress would also send errors but don't need it here as errors
-		// are handled by session.Run() and ImageBuild()
-		if err := addDirToSession(s, contextDir, progressOutput, syncDone); err != nil {
-			return err
-		}
-
-		buf := newBufferedWriter(syncDone, buildBuff)
-		defer func() {
-			select {
-			case <-buf.flushed:
-			case <-ctx.Done():
-			}
-		}()
-		buildBuff = buf
-
-		remote = clientSessionRemote
-		body = buildCtx
-	}
-
 	configFile := dockerCli.ConfigFile()
 	creds, _ := configFile.GetAllCredentials()
 	authConfigs := make(map[string]types.AuthConfig, len(creds))
@@ -411,20 +370,6 @@ func runBuild(dockerCli command.Cli, options buildOptions) error {
 	buildOptions.AuthConfigs = authConfigs
 	buildOptions.RemoteContext = remote
 
-	if s != nil {
-		go func() {
-			logrus.Debugf("running session: %v", s.ID())
-			dialSession := func(ctx context.Context, proto string, meta map[string][]string) (net.Conn, error) {
-				return dockerCli.Client().DialHijack(ctx, "/session", proto, meta)
-			}
-			if err := s.Run(ctx, dialSession); err != nil {
-				logrus.Error(err)
-				cancel() // cancel progress context
-			}
-		}()
-		buildOptions.SessionID = s.ID()
-	}
-
 	response, err := dockerCli.Client().ImageBuild(ctx, body, buildOptions)
 	if err != nil {
 		if options.quiet {

cli/command/image/build_session.go

@@ -1,28 +1,20 @@
 package image
 
 import (
-	"bytes"
 	"context"
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
-	"io"
 	"io/ioutil"
 	"os"
 	"path/filepath"
-	"sync"
-	"time"
 
 	"github.com/docker/cli/cli/command"
-	"github.com/docker/cli/cli/command/image/build"
 	cliconfig "github.com/docker/cli/cli/config"
 	"github.com/docker/docker/api/types/versions"
-	"github.com/docker/docker/pkg/progress"
 	"github.com/moby/buildkit/session"
-	"github.com/moby/buildkit/session/filesync"
 	"github.com/pkg/errors"
-	"golang.org/x/time/rate"
 )
 
 const clientSessionRemote = "client-session"
@@ -49,87 +41,6 @@ func trySession(dockerCli command.Cli, contextDir string, forStream bool) (*sess
 	return s, nil
 }
 
-func addDirToSession(session *session.Session, contextDir string, progressOutput progress.Output, done chan error) error {
-	excludes, err := build.ReadDockerignore(contextDir)
-	if err != nil {
-		return err
-	}
-
-	p := &sizeProgress{out: progressOutput, action: "Streaming build context to Docker daemon"}
-
-	workdirProvider := filesync.NewFSSyncProvider([]filesync.SyncedDir{
-		{Dir: contextDir, Excludes: excludes},
-	})
-	session.Allow(workdirProvider)
-
-	// this will be replaced on parallel build jobs. keep the current
-	// progressbar for now
-	if snpc, ok := workdirProvider.(interface {
-		SetNextProgressCallback(func(int, bool), chan error)
-	}); ok {
-		snpc.SetNextProgressCallback(p.update, done)
-	}
-
-	return nil
-}
-
-type sizeProgress struct {
-	out     progress.Output
-	action  string
-	limiter *rate.Limiter
-}
-
-func (sp *sizeProgress) update(size int, last bool) {
-	if sp.limiter == nil {
-		sp.limiter = rate.NewLimiter(rate.Every(100*time.Millisecond), 1)
-	}
-	if last || sp.limiter.Allow() {
-		sp.out.WriteProgress(progress.Progress{Action: sp.action, Current: int64(size), LastUpdate: last})
-	}
-}
-
-type bufferedWriter struct {
-	done chan error
-	io.Writer
-	buf     *bytes.Buffer
-	flushed chan struct{}
-	mu      sync.Mutex
-}
-
-func newBufferedWriter(done chan error, w io.Writer) *bufferedWriter {
-	bw := &bufferedWriter{done: done, Writer: w, buf: new(bytes.Buffer), flushed: make(chan struct{})}
-	go func() {
-		<-done
-		bw.flushBuffer()
-	}()
-	return bw
-}
-
-func (bw *bufferedWriter) Write(dt []byte) (int, error) {
-	select {
-	case <-bw.done:
-		bw.flushBuffer()
-		return bw.Writer.Write(dt)
-	default:
-		return bw.buf.Write(dt)
-	}
-}
-
-func (bw *bufferedWriter) flushBuffer() {
-	bw.mu.Lock()
-	select {
-	case <-bw.flushed:
-	default:
-		bw.Writer.Write(bw.buf.Bytes())
-		close(bw.flushed)
-	}
-	bw.mu.Unlock()
-}
-
-func (bw *bufferedWriter) String() string {
-	return fmt.Sprintf("%s", bw.Writer)
-}
-
 func getBuildSharedKey(dir string) (string, error) {
 	// build session is hash of build dir with node based randomness
 	s := sha256.Sum256([]byte(fmt.Sprintf("%s:%s", tryNodeIdentifier(), dir)))