fix: always absolute paths when tarring files to a Docker container

docker_test.go

@@ -2109,11 +2109,23 @@ func TestDockerCreateContainerWithDirs(t *testing.T) {
 	ctx := context.Background()
 	hostDirName := "testresources"
 
+	abs, err := filepath.Abs("./" + hostDirName)
+	assert.Nil(t, err)
+
 	tests := []struct {
 		name     string
 		dir      ContainerFile
 		hasError bool
 	}{
+		{
+			name: "success copy directory with full path",
+			dir: ContainerFile{
+				HostFilePath:      abs,
+				ContainerFilePath: "/tmp/" + hostDirName, // the parent dir must exist
+				FileMode:          700,
+			},
+			hasError: false,
+		},
 		{
 			name: "success copy directory",
 			dir: ContainerFile{
@@ -2561,10 +2573,11 @@ func assertExtractedFiles(t *testing.T, ctx context.Context, container Container
 			require.NoError(t, err)
 		}
 
+		fp := filepath.Join(containerFilePath, srcFile.Name())
 		// copy file by file, as there is a limitation in the Docker client to copy an entiry directory from the container
 		// paths for the container files are using Linux path separators
-		fd, err := container.CopyFileFromContainer(ctx, containerFilePath+"/"+srcFile.Name())
-		require.NoError(t, err, "Path not found in container: %s", containerFilePath+"/"+srcFile.Name())
+		fd, err := container.CopyFileFromContainer(ctx, fp)
+		require.NoError(t, err, "Path not found in container: %s", fp)
 		defer fd.Close()
 
 		targetPath := filepath.Join(tmpDir, srcFile.Name())

file.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
 func isDir(path string) (bool, error) {
@@ -39,6 +40,8 @@ func tarDir(src string, fileMode int64) (*bytes.Buffer, error) {
 	zr := gzip.NewWriter(buffer)
 	tw := tar.NewWriter(zr)
 
+	parentDir, _ := filepath.Split(src)
+
 	// walk through every file in the folder
 	err := filepath.Walk(src, func(file string, fi os.FileInfo, errFn error) error {
 		if errFn != nil {
@@ -57,9 +60,8 @@ func tarDir(src string, fileMode int64) (*bytes.Buffer, error) {
 			return fmt.Errorf("error getting file info header: %w", err)
 		}
 
-		// must provide real name
-		// (see https://golang.org/src/archive/tar/common.go?#L626)
-		header.Name = filepath.ToSlash(file)
+		// keep the path relative to the parent directory
+		header.Name = filepath.ToSlash(strings.Replace(file, parentDir, "", 1))
 		header.Mode = fileMode
 
 		// write header

file_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func Test_IsDir(t *testing.T) {
@@ -53,38 +54,60 @@ func Test_IsDir(t *testing.T) {
 }
 
 func Test_TarDir(t *testing.T) {
-	src := filepath.Join(".", "testresources")
-
-	buff, err := tarDir(src, 0755)
-	if err != nil {
-		t.Fatal(err)
+	originalSrc := filepath.Join(".", "testresources")
+	tests := []struct {
+		abs bool
+	}{
+		{
+			abs: false,
+		},
+		{
+			abs: true,
+		},
 	}
 
-	tmpDir := filepath.Join(t.TempDir(), "subfolder")
-	err = untar(tmpDir, bytes.NewReader(buff.Bytes()))
-	if err != nil {
-		t.Fatal(err)
-	}
+	for _, test := range tests {
+		t.Run(fmt.Sprintf("TarDir with abs=%t", test.abs), func(t *testing.T) {
+			src := originalSrc
+			if test.abs {
+				absSrc, err := filepath.Abs(src)
+				require.Nil(t, err)
 
-	srcFiles, err := os.ReadDir(src)
-	if err != nil {
-		log.Fatal(err)
-	}
+				src = absSrc
+			}
 
-	for _, srcFile := range srcFiles {
-		if srcFile.IsDir() {
-			continue
-		}
-		srcBytes, err := os.ReadFile(filepath.Join(src, srcFile.Name()))
-		if err != nil {
-			t.Fatal(err)
-		}
+			buff, err := tarDir(src, 0755)
+			if err != nil {
+				t.Fatal(err)
+			}
 
-		untarBytes, err := os.ReadFile(filepath.Join(tmpDir, "testresources", srcFile.Name()))
-		if err != nil {
-			t.Fatal(err)
-		}
-		assert.Equal(t, srcBytes, untarBytes)
+			tmpDir := filepath.Join(t.TempDir(), "subfolder")
+			err = untar(tmpDir, bytes.NewReader(buff.Bytes()))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			srcFiles, err := os.ReadDir(src)
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			for _, srcFile := range srcFiles {
+				if srcFile.IsDir() {
+					continue
+				}
+				srcBytes, err := os.ReadFile(filepath.Join(src, srcFile.Name()))
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				untarBytes, err := os.ReadFile(filepath.Join(tmpDir, "testresources", srcFile.Name()))
+				if err != nil {
+					t.Fatal(err)
+				}
+				assert.Equal(t, srcBytes, untarBytes)
+			}
+		})
 	}
 }