updated hash.go and tar.go

Signed-off-by: Suleiman Dibirov <idsulik@gmail.com>

pkg/compose/hash.go

@@ -20,12 +20,10 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"os"
-	"path/filepath"
+	"github.com/docker/compose/v2/pkg/utils"
 	"time"
 
 	"github.com/compose-spec/compose-go/v2/types"
-	"github.com/docker/compose/v2/pkg/utils"
 	"github.com/opencontainers/go-digest"
 )
 
@@ -88,10 +86,13 @@ func createTarForConfig(
 ) (*bytes.Buffer, error) {
 	// fixed time to ensure the tarball is deterministic
 	modTime := time.Unix(0, 0)
-	content := make([]byte, 0)
+
+	if serviceConfig.Target == "" {
+		serviceConfig.Target = "/" + serviceConfig.Source
+	}
 
 	if file.Content != "" {
-		content = []byte(file.Content)
+		return bytes.NewBuffer([]byte(file.Content)), nil
 	} else if file.Environment != "" {
 		env, ok := project.Environment[file.Environment]
 		if !ok {
@@ -101,67 +102,10 @@ func createTarForConfig(
 				file.Name,
 			)
 		}
-		content = []byte(env)
+		return bytes.NewBuffer([]byte(env)), nil
 	} else if file.File != "" {
-		var err error
-		content, err = readPathContent(file.File)
-
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if len(content) == 0 {
-		return nil, fmt.Errorf("config %q is empty", file.Name)
-	}
-
-	if serviceConfig.Target == "" {
-		serviceConfig.Target = "/" + serviceConfig.Source
-	}
-
-	b, err := utils.CreateTar(content, serviceConfig, modTime)
-	if err != nil {
-		return nil, err
-	}
-
-	return &b, nil
-}
-
-func readPathContent(path string) ([]byte, error) {
-	content := make([]byte, 0)
-
-	// Check if the path is a directory
-	info, err := os.Stat(path)
-	if err != nil {
-		return nil, fmt.Errorf("error accessing path %q: %v", path, err)
-	}
-
-	if info.IsDir() {
-		// If it's a directory, read all files and concatenate their contents
-		err = filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
-			if err != nil {
-				return err
-			}
-			if !info.IsDir() {
-				fileContent, err := os.ReadFile(path)
-				if err != nil {
-					return err
-				}
-				content = append(content, fileContent...)
-			}
-			return nil
-		})
-		if err != nil {
-			return nil, fmt.Errorf("error reading directory %q: %v", path, err)
-		}
-	} else {
-		// If it's a file, read its content
-		fileContent, err := os.ReadFile(path)
-		if err != nil {
-			return nil, fmt.Errorf("error reading file %q: %v", path, err)
-		}
-		content = fileContent
+		return utils.CreateTarByPath(file.File, modTime)
 	}
 
-	return content, nil
+	return nil, fmt.Errorf("config %q is empty", file.Name)
 }

pkg/utils/tar.go

@@ -19,6 +19,9 @@ package utils
 import (
 	"archive/tar"
 	"bytes"
+	"io"
+	"os"
+	"path/filepath"
 	"strconv"
 	"time"
 
@@ -68,3 +71,58 @@ func CreateTar(content []byte, config types.FileReferenceConfig, modTime time.Ti
 	err = tarWriter.Close()
 	return b, err
 }
+
+func CreateTarByPath(path string, modTime time.Time) (*bytes.Buffer, error) {
+	b := new(bytes.Buffer)
+	tw := tar.NewWriter(b)
+	defer tw.Close()
+
+	// Walk the directory or file tree at the given path
+	err := filepath.Walk(path, func(file string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Create tar header
+		header, err := tar.FileInfoHeader(fi, fi.Name())
+		if err != nil {
+			return err
+		}
+
+		// Preserve folder structure by using relative paths
+		header.Name, err = filepath.Rel(filepath.Dir(path), file)
+		if err != nil {
+			return err
+		}
+
+		// Set custom modification time
+		header.ModTime = modTime
+
+		// Write header to the tarball
+		if err := tw.WriteHeader(header); err != nil {
+			return err
+		}
+
+		// If it's a directory, we don't need to write file content
+		if fi.Mode().IsRegular() {
+			// Open the file and write its contents
+			f, err := os.Open(file)
+			if err != nil {
+				return err
+			}
+			defer f.Close()
+
+			if _, err := io.Copy(tw, f); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return b, nil
+}