Do not make hidden directory inside builder shim

pkg/build/build.go

@@ -137,8 +137,8 @@ func Build(ctx context.Context, opts *BOpts) error {
 		KeyContentStoreName: opts.ContentStore,
 	}
 
-	if opts.HiddenDirName != "" {
-		solveOpt.FrontendAttrs["filename"] = filepath.Join(opts.HiddenDirName, "Dockerfile")
+	if opts.HiddenDockerDir != "" {
+		solveOpt.FrontendAttrs["filename"] = filepath.Join(opts.HiddenDockerDir, "Dockerfile")
 	}
 
 	if opts.NoCache {

pkg/build/buildopts.go

@@ -20,12 +20,10 @@ import (
 	"bytes"
 	"context"
 	"encoding/base64"
-	"fmt"
 	"path/filepath"
 	"strings"
 
 	"github.com/containerd/platforms"
-	"github.com/google/uuid"
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
 	"github.com/moby/buildkit/util/progress/progresswriter"
@@ -43,8 +41,9 @@ const (
 	KeyContentStoreName = "container"
 	// Base64-encoded Dockerfile contents.
 	KeyDockerfile = "dockerfile"
-	// Base64-encoded docker specific ignore file contents.
-	KeyDockerignore = "dockerignore"
+	// Hidden directory for the dockerfile and dockerignore to be placed.
+	// This is provided when docker specific ignore file is found, which might live outside the build context.
+	KeyHiddenDockerDir = "hidden-docker-dir"
 	// Image reference (name:tag) to assign to the built image.
 	KeyTag = "tag"
 	// Target platforms to build the image for.
@@ -80,22 +79,22 @@ const (
 var keyBOpts = struct{}{}
 
 type BOpts struct {
-	BuildID        string
-	Dockerfile     []byte
-	Tag            string
-	ContextDir     string
-	HiddenDirName  string
-	BuildPlatforms []ocispecs.Platform
-	Platforms      []ocispecs.Platform
-	NoCache        bool
-	Target         string
-	BuildArgs      map[string]string
-	Secrets        map[string][]byte
-	CacheIn        []string
-	CacheOut       []string
-	Outputs        []string
-	Labels         map[string]string
-	ProgressWriter progresswriter.Writer
+	BuildID         string
+	Dockerfile      []byte
+	Tag             string
+	ContextDir      string
+	HiddenDockerDir string
+	BuildPlatforms  []ocispecs.Platform
+	Platforms       []ocispecs.Platform
+	NoCache         bool
+	Target          string
+	BuildArgs       map[string]string
+	Secrets         map[string][]byte
+	CacheIn         []string
+	CacheOut        []string
+	Outputs         []string
+	Labels          map[string]string
+	ProgressWriter  progresswriter.Writer
 
 	ContentStore *content.ContentStoreProxy
 	Resolver     *resolver.ResolverProxy
@@ -129,19 +128,7 @@ func NewBuildOpts(ctx context.Context, basePath string, contextMap map[string][]
 		return nil, err
 	}
 
-	var dockerignoreBytes = []byte(nil)
-	var hiddenDirName = ""
-
-	dockerignoreBase64Bytes, ok := first(KeyDockerignore)
-	if ok {
-		dockerignoreBytes, err = base64.StdEncoding.DecodeString(dockerignoreBase64Bytes)
-		if err != nil {
-			return nil, err
-		}
-
-		hiddenDirName = ".tmp-" + uuid.NewString()
-		dockerignoreBytes = append(dockerignoreBytes, fmt.Sprintf("\n%s", hiddenDirName)...)
-	}
+	hiddenDockerDir, _ := first(KeyHiddenDockerDir)
 
 	progress, ok := first(KeyProgress)
 	if !ok {
@@ -306,7 +293,7 @@ func NewBuildOpts(ctx context.Context, basePath string, contextMap map[string][]
 		}
 	}
 
-	fssyncProxy, err := fssync.NewFSSyncProxy(".", basePath, hiddenDirName, dockerfileBytes, dockerignoreBytes, addedGlobs)
+	fssyncProxy, err := fssync.NewFSSyncProxy(".", basePath, addedGlobs)
 	if err != nil {
 		return nil, err
 	}
@@ -317,27 +304,27 @@ func NewBuildOpts(ctx context.Context, basePath string, contextMap map[string][]
 	}
 
 	bopts := &BOpts{
-		BuildID:        buildID,
-		Dockerfile:     dockerfileBytes,
-		Tag:            tag,
-		BuildPlatforms: bps,
-		Platforms:      pls,
-		ContextDir:     ctxDir,
-		HiddenDirName:  hiddenDirName,
-		ContentStore:   contentProxy,
-		FSSync:         fssyncProxy,
-		NoCache:        noCache,
-		Resolver:       resolver.NewResolverProxy(),
-		ProgressWriter: pw,
-		Stdio:          stdioProxy,
-		Target:         target,
-		Labels:         labels,
-		BuildArgs:      buildArgs,
-		Secrets:        secrets,
-		CacheIn:        cacheIn,
-		CacheOut:       cacheOut,
-		Outputs:        outputs,
-		basePath:       filepath.Join(basePath, buildID),
+		BuildID:         buildID,
+		Dockerfile:      dockerfileBytes,
+		Tag:             tag,
+		BuildPlatforms:  bps,
+		Platforms:       pls,
+		ContextDir:      ctxDir,
+		HiddenDockerDir: hiddenDockerDir,
+		ContentStore:    contentProxy,
+		FSSync:          fssyncProxy,
+		NoCache:         noCache,
+		Resolver:        resolver.NewResolverProxy(),
+		ProgressWriter:  pw,
+		Stdio:           stdioProxy,
+		Target:          target,
+		Labels:          labels,
+		BuildArgs:       buildArgs,
+		Secrets:         secrets,
+		CacheIn:         cacheIn,
+		CacheOut:        cacheOut,
+		Outputs:         outputs,
+		basePath:        filepath.Join(basePath, buildID),
 	}
 
 	return bopts, nil

pkg/fileutils/tarxfer.go

@@ -40,13 +40,7 @@ func NewTarReceiver(cacheBase string, demux *stream.Demultiplexer) *Receiver {
 	return &Receiver{demux: demux, cacheBase: cacheBase}
 }
 
-func (r *Receiver) Receive(
-	ctx context.Context,
-	hiddenDirName string,
-	dockerfileBytes []byte,
-	dockerignoreBytes []byte,
-	fn fs.WalkDirFunc) (string, error) {
-
+func (r *Receiver) Receive(ctx context.Context, fn fs.WalkDirFunc) (string, error) {
 	errCh := make(chan error, 1)
 	hashCh := make(chan string, 1)
 	dataCh := make(chan []byte)
@@ -91,36 +85,6 @@ func (r *Receiver) Receive(
 		_ = os.Remove(tarFile)
 	}
 
-	if hiddenDirName != "" {
-		dockerfilePath := filepath.Join(cacheDir, filepath.Join(hiddenDirName, "Dockerfile"))
-		dockerignorePath := filepath.Join(cacheDir, filepath.Join(hiddenDirName, "Dockerfile.dockerignore"))
-
-		if err := os.MkdirAll(filepath.Dir(dockerfilePath), 0o755); err != nil {
-			return "", err
-		}
-
-		dockerfile, err := os.OpenFile(dockerfilePath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o644)
-		if err != nil {
-			return "", err
-		}
-		if _, err := dockerfile.Write(dockerfileBytes); err != nil {
-			_ = dockerfile.Close()
-			return "", err
-		}
-		defer dockerfile.Close()
-
-		dockerignore, err := os.OpenFile(dockerignorePath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o644)
-		if err != nil {
-			return "", err
-		}
-		defer dockerignore.Close()
-
-		if _, err := dockerignore.Write(dockerignoreBytes); err != nil {
-			_ = dockerignore.Close()
-			return "", err
-		}
-	}
-
 	return checksum, filepath.Walk(cacheDir, func(p string, info os.FileInfo, _ error) error {
 		rel, err := filepath.Rel(cacheDir, p)
 		if err != nil || rel == "." {

pkg/fileutils/tarxfer_test.go

@@ -95,7 +95,7 @@ func TestReceiver_Receive_Success(t *testing.T) {
 		return nil
 	}
 
-	checksum, err := r.Receive(ctx, "", nil, nil, walkFn)
+	checksum, err := r.Receive(ctx, walkFn)
 	if err != nil {
 		t.Fatalf("Receive returned error: %v", err)
 	}
@@ -125,7 +125,7 @@ func TestReceiver_Receive_ServerError(t *testing.T) {
 	tmpDir := t.TempDir()
 	r := NewTarReceiver(tmpDir, demux)
 
-	_, err := r.Receive(ctx, "", nil, nil, func(string, fs.DirEntry, error) error { return nil })
+	_, err := r.Receive(ctx, func(string, fs.DirEntry, error) error { return nil })
 	if err == nil {
 		t.Fatalf("expected server error, got nil")
 	}

pkg/fssync/fssync.go

@@ -45,23 +45,14 @@ type FSSyncProxy struct {
 	contextDir string
 	basePath   string
 
-	hiddenDirName string
-	dockerfile    []byte
-	dockerignore  []byte
-
 	addedGlobs []string
 }
 
-func NewFSSyncProxy(
-	contextDir string, basePath string, hiddenDirName string,
-	dockerfile []byte, dockerignore []byte, addedGlobs []string) (*FSSyncProxy, error) {
+func NewFSSyncProxy(contextDir string, basePath string, addedGlobs []string) (*FSSyncProxy, error) {
 
 	f := new(FSSyncProxy)
 	f.contextDir = contextDir
 	f.basePath = filepath.Join(basePath, f.String())
-	f.hiddenDirName = hiddenDirName
-	f.dockerfile = dockerfile
-	f.dockerignore = dockerignore
 	f.addedGlobs = addedGlobs
 	return f, nil
 }

pkg/fssync/walk.go

@@ -124,15 +124,14 @@ func (f *FS) Walk(ctx context.Context, target string, fn fs.WalkDirFunc) error {
 	switch walkMeta.Mode {
 	case ModeTAR:
 		receiver := fileutils.NewTarReceiver(f.fsPath, demux)
-		checksum, err := receiver.Receive(ctx, f.proxy.hiddenDirName, f.proxy.dockerfile, f.proxy.dockerignore,
-			func(path string, d fs.DirEntry, err error) error {
-				excluded, err := excludeMatcher.MatchesOrParentMatches(path)
-				if excluded {
-					return nil
-				}
-
-				return fn(path, d, err)
-			})
+		checksum, err := receiver.Receive(ctx, func(path string, d fs.DirEntry, err error) error {
+			excluded, err := excludeMatcher.MatchesOrParentMatches(path)
+			if excluded {
+				return nil
+			}
+
+			return fn(path, d, err)
+		})
 		if err != nil {
 			return err
 		}