builder: remove legacy build's session handling

This feature was used by docker build --stream and it was kept experimental.

Users of this endpoint should enable BuildKit anyway by setting Version to BuilderBuildKit.

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

api/server/backend/build/backend.go

@@ -9,11 +9,9 @@ import (
 	"github.com/docker/docker/api/types/backend"
 	"github.com/docker/docker/builder"
 	buildkit "github.com/docker/docker/builder/builder-next"
-	"github.com/docker/docker/builder/fscache"
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/pkg/errors"
-	"golang.org/x/sync/errgroup"
 	"google.golang.org/grpc"
 )
 
@@ -31,14 +29,13 @@ type Builder interface {
 // Backend provides build functionality to the API router
 type Backend struct {
 	builder        Builder
-	fsCache        *fscache.FSCache
 	imageComponent ImageComponent
 	buildkit       *buildkit.Builder
 }
 
 // NewBackend creates a new build backend from components
-func NewBackend(components ImageComponent, builder Builder, fsCache *fscache.FSCache, buildkit *buildkit.Builder) (*Backend, error) {
-	return &Backend{imageComponent: components, builder: builder, fsCache: fsCache, buildkit: buildkit}, nil
+func NewBackend(components ImageComponent, builder Builder, buildkit *buildkit.Builder) (*Backend, error) {
+	return &Backend{imageComponent: components, builder: builder, buildkit: buildkit}, nil
 }
 
 // RegisterGRPC registers buildkit controller to the grpc server.
@@ -99,34 +96,11 @@ func (b *Backend) Build(ctx context.Context, config backend.BuildConfig) (string
 
 // PruneCache removes all cached build sources
 func (b *Backend) PruneCache(ctx context.Context, opts types.BuildCachePruneOptions) (*types.BuildCachePruneReport, error) {
-	eg, ctx := errgroup.WithContext(ctx)
-
-	var fsCacheSize uint64
-	eg.Go(func() error {
-		var err error
-		fsCacheSize, err = b.fsCache.Prune(ctx)
-		if err != nil {
-			return errors.Wrap(err, "failed to prune fscache")
-		}
-		return nil
-	})
-
-	var buildCacheSize int64
-	var cacheIDs []string
-	eg.Go(func() error {
-		var err error
-		buildCacheSize, cacheIDs, err = b.buildkit.Prune(ctx, opts)
-		if err != nil {
-			return errors.Wrap(err, "failed to prune build cache")
-		}
-		return nil
-	})
-
-	if err := eg.Wait(); err != nil {
-		return nil, err
+	buildCacheSize, cacheIDs, err := b.buildkit.Prune(ctx, opts)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to prune build cache")
 	}
-
-	return &types.BuildCachePruneReport{SpaceReclaimed: fsCacheSize + uint64(buildCacheSize), CachesDeleted: cacheIDs}, nil
+	return &types.BuildCachePruneReport{SpaceReclaimed: uint64(buildCacheSize), CachesDeleted: cacheIDs}, nil
 }
 
 // Cancel cancels the build by ID

api/server/router/system/system.go

@@ -3,7 +3,6 @@ package system // import "github.com/docker/docker/api/server/router/system"
 import (
 	"github.com/docker/docker/api/server/router"
 	buildkit "github.com/docker/docker/builder/builder-next"
-	"github.com/docker/docker/builder/fscache"
 )
 
 // systemRouter provides information about the Docker system overall.
@@ -12,17 +11,15 @@ type systemRouter struct {
 	backend  Backend
 	cluster  ClusterBackend
 	routes   []router.Route
-	fscache  *fscache.FSCache // legacy
 	builder  *buildkit.Builder
 	features *map[string]bool
 }
 
 // NewRouter initializes a new system router
-func NewRouter(b Backend, c ClusterBackend, fscache *fscache.FSCache, builder *buildkit.Builder, features *map[string]bool) router.Router {
+func NewRouter(b Backend, c ClusterBackend, builder *buildkit.Builder, features *map[string]bool) router.Router {
 	r := &systemRouter{
 		backend:  b,
 		cluster:  c,
-		fscache:  fscache,
 		builder:  builder,
 		features: features,
 	}

api/server/router/system/system_routes.go

@@ -101,16 +101,6 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		return err
 	})
 
-	var builderSize int64 // legacy
-	eg.Go(func() error {
-		var err error
-		builderSize, err = s.fscache.DiskUsage(ctx)
-		if err != nil {
-			return pkgerrors.Wrap(err, "error getting fscache build cache usage")
-		}
-		return nil
-	})
-
 	var buildCache []*types.BuildCache
 	eg.Go(func() error {
 		var err error
@@ -125,6 +115,7 @@ func (s *systemRouter) getDiskUsage(ctx context.Context, w http.ResponseWriter,
 		return err
 	}
 
+	var builderSize int64
 	for _, b := range buildCache {
 		builderSize += b.Size
 	}

builder/dockerfile/builder.go

@@ -8,14 +8,12 @@ import (
 	"io/ioutil"
 	"sort"
 	"strings"
-	"time"
 
 	"github.com/containerd/containerd/platforms"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/backend"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/builder"
-	"github.com/docker/docker/builder/fscache"
 	"github.com/docker/docker/builder/remotecontext"
 	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/pkg/idtools"
@@ -25,7 +23,6 @@ import (
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
 	"github.com/moby/buildkit/frontend/dockerfile/shell"
-	"github.com/moby/buildkit/session"
 	specs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -49,31 +46,19 @@ const (
 	stepFormat = "Step %d/%d : %v"
 )
 
-// SessionGetter is object used to get access to a session by uuid
-type SessionGetter interface {
-	Get(ctx context.Context, uuid string) (session.Caller, error)
-}
-
 // BuildManager is shared across all Builder objects
 type BuildManager struct {
 	idMapping *idtools.IdentityMapping
 	backend   builder.Backend
 	pathCache pathCache // TODO: make this persistent
-	sg        SessionGetter
-	fsCache   *fscache.FSCache
 }
 
 // NewBuildManager creates a BuildManager
-func NewBuildManager(b builder.Backend, sg SessionGetter, fsCache *fscache.FSCache, identityMapping *idtools.IdentityMapping) (*BuildManager, error) {
+func NewBuildManager(b builder.Backend, identityMapping *idtools.IdentityMapping) (*BuildManager, error) {
 	bm := &BuildManager{
 		backend:   b,
 		pathCache: &syncmap.Map{},
-		sg:        sg,
 		idMapping: identityMapping,
-		fsCache:   fsCache,
-	}
-	if err := fsCache.RegisterTransport(remotecontext.ClientSessionRemote, NewClientSessionTransport()); err != nil {
-		return nil, err
 	}
 	return bm, nil
 }
@@ -100,10 +85,8 @@ func (bm *BuildManager) Build(ctx context.Context, config backend.BuildConfig) (
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	if src, err := bm.initializeClientSession(ctx, cancel, config.Options); err != nil {
-		return nil, err
-	} else if src != nil {
-		source = src
+	if config.Options.SessionID != "" {
+		return nil, errors.New("experimental session with v1 builder is no longer supported, use builder version v2 (BuildKit) instead")
 	}
 
 	builderOptions := builderOptions{
@@ -120,39 +103,6 @@ func (bm *BuildManager) Build(ctx context.Context, config backend.BuildConfig) (
 	return b.build(source, dockerfile)
 }
 
-func (bm *BuildManager) initializeClientSession(ctx context.Context, cancel func(), options *types.ImageBuildOptions) (builder.Source, error) {
-	if options.SessionID == "" || bm.sg == nil {
-		return nil, nil
-	}
-	logrus.Debug("client is session enabled")
-
-	connectCtx, cancelCtx := context.WithTimeout(ctx, sessionConnectTimeout)
-	defer cancelCtx()
-
-	c, err := bm.sg.Get(connectCtx, options.SessionID)
-	if err != nil {
-		return nil, err
-	}
-	go func() {
-		<-c.Context().Done()
-		cancel()
-	}()
-	if options.RemoteContext == remotecontext.ClientSessionRemote {
-		st := time.Now()
-		csi, err := NewClientSessionSourceIdentifier(ctx, bm.sg, options.SessionID)
-		if err != nil {
-			return nil, err
-		}
-		src, err := bm.fsCache.SyncFrom(ctx, csi)
-		if err != nil {
-			return nil, err
-		}
-		logrus.Debugf("sync-time: %v", time.Since(st))
-		return src, nil
-	}
-	return nil, nil
-}
-
 // builderOptions are the dependencies required by the builder
 type builderOptions struct {
 	Options        *types.ImageBuildOptions