From 045ded60db36980079389c6714325dce134f9670 Mon Sep 17 00:00:00 2001
From: Ethan Li <lietk12@gmail.com>
Date: Wed, 15 May 2024 19:00:51 -0400
Subject: [PATCH] Fix export of symlinks from archives & OCI images (#209)

---
 CHANGELOG.md                     |  6 ++++
 internal/app/forklift/bundles.go | 54 +++++++++++++++++++++-----------
 2 files changed, 42 insertions(+), 18 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 298eed5d..64bcd6f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.7.2-alpha.5 - 2024-05-15
+
+### Fixed
+
+- (cli) Symlinks are now handled correctly when they need to be exported from downloaded archives or OCI images.
+
 ## 0.7.2-alpha.4 - 2024-05-15
 
 ### Fixed
diff --git a/internal/app/forklift/bundles.go b/internal/app/forklift/bundles.go
index d66ae07d..109ba01e 100644
--- a/internal/app/forklift/bundles.go
+++ b/internal/app/forklift/bundles.go
@@ -365,11 +365,10 @@ func determineFileType(
 	return filetype.MatchReader(archiveFile)
 }
 
-func extractFile(tarReader *tar.Reader, sourcePath string, exportPath string) error {
+func extractFile(tarReader *tar.Reader, sourcePath, exportPath string) error {
 	if sourcePath == "/" || sourcePath == "." {
 		sourcePath = ""
 	}
-	fmt.Printf("exporting into %s...\n", exportPath)
 	for {
 		header, err := tarReader.Next()
 		if err == io.EOF {
@@ -391,27 +390,21 @@ func extractFile(tarReader *tar.Reader, sourcePath string, exportPath string) er
 		case tar.TypeDir:
 			if err = EnsureExists(filepath.FromSlash(targetPath)); err != nil {
 				return errors.Wrapf(
-					err, "couldn't export %s from archive to %s", header.Name, targetPath,
+					err, "couldn't export directory %s from archive to %s", header.Name, targetPath,
 				)
 			}
 		case tar.TypeReg:
-			targetFile, err := os.OpenFile(
-				filepath.FromSlash(targetPath), os.O_RDWR|os.O_CREATE|os.O_TRUNC,
-				fs.FileMode(header.Mode&int64(fs.ModePerm)),
-			)
-			if err != nil {
-				return errors.Wrapf(err, "couldn't create export file at %s", targetPath)
+			if err = extractRegularFile(header, tarReader, sourcePath, targetPath); err != nil {
+				return errors.Wrapf(
+					err, "couldn't export regular file %s from archive to %s", header.Name, targetPath,
+				)
 			}
-			defer func(file fs.File, filePath string) {
-				if err := file.Close(); err != nil {
-					// FIXME: handle this error better
-					fmt.Printf("Error: couldn't close export file %s\n", filePath)
-				}
-			}(targetFile, targetPath)
-
-			if _, err = io.Copy(targetFile, tarReader); err != nil {
+		case tar.TypeSymlink:
+			if err = os.Symlink(
+				filepath.FromSlash(header.Linkname), filepath.FromSlash(targetPath),
+			); err != nil {
 				return errors.Wrapf(
-					err, "couldn't copy file %s in tar archive to %s", sourcePath, targetPath,
+					err, "couldn't export symlink %s from archive to %s", header.Name, targetPath,
 				)
 			}
 		}
@@ -419,6 +412,31 @@ func extractFile(tarReader *tar.Reader, sourcePath string, exportPath string) er
 	return nil
 }
 
+func extractRegularFile(
+	header *tar.Header, tarReader *tar.Reader, sourcePath, targetPath string,
+) error {
+	targetFile, err := os.OpenFile(
+		filepath.FromSlash(targetPath), os.O_RDWR|os.O_CREATE|os.O_TRUNC,
+		fs.FileMode(header.Mode&int64(fs.ModePerm)),
+	)
+	if err != nil {
+		return errors.Wrapf(err, "couldn't create export file at %s", targetPath)
+	}
+	defer func(file fs.File, filePath string) {
+		if err := file.Close(); err != nil {
+			// FIXME: handle this error better
+			fmt.Printf("Error: couldn't close export file %s\n", filePath)
+		}
+	}(targetFile, targetPath)
+
+	if _, err = io.Copy(targetFile, tarReader); err != nil {
+		return errors.Wrapf(
+			err, "couldn't copy file %s in tar archive to %s", sourcePath, targetPath,
+		)
+	}
+	return nil
+}
+
 // FSBundle: FSRepoLoader
 
 func (b *FSBundle) LoadFSRepo(repoPath string, version string) (*core.FSRepo, error) {