feat: moved and updated archive utility

internal/archive/archive.go

@@ -0,0 +1,103 @@
+package archive
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"io"
+	"os"
+	"strings"
+
+	makeshift "git.towk2.me/towk/makeshift/pkg"
+)
+
+func Create(filenames []string, buf io.Writer, hooks []makeshift.Hook) error {
+	// Create new Writers for gzip and tar
+	// These writers are chained. Writing to the tar writer will
+	// write to the gzip writer which in turn will write to
+	// the "buf" writer
+	gw := gzip.NewWriter(buf)
+	defer gw.Close()
+	tw := tar.NewWriter(gw)
+	defer tw.Close()
+
+	// Iterate over files and add them to the tar archive
+	for _, filename := range filenames {
+		err := addToArchive(tw, filename, hooks)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func Expand(path string) error {
+	return nil
+}
+
+func addToArchive(tw *tar.Writer, filename string, hooks []makeshift.Hook) error {
+	var (
+		hook makeshift.Hook
+		file *os.File
+		data any
+		err  error
+	)
+	// open file to write to archive
+	file, err = os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// run pre-hooks to modify the contents of the file
+	// before archiving using plugins
+	for _, hook := range hooks {
+		err = hook.Run()
+		if err != nil {
+			return err
+		}
+	}
+
+	// get FileInfo for file size, mode, etc.
+	info, err := file.Stat()
+	if err != nil {
+		return err
+	}
+
+	// skip file if it's a directory
+	if info.IsDir() {
+		return nil
+	}
+
+	// create a tar Header from the FileInfo data
+	header, err := tar.FileInfoHeader(info, info.Name())
+	if err != nil {
+		return err
+	}
+
+	// use full path as name (FileInfoHeader only takes the basename) to
+	// preserve directory structure
+	// see for more info: https://golang.org/src/archive/tar/common.go?#L626
+	header.Name = filename
+
+	// Write file header to the tar archive
+	err = tw.WriteHeader(header)
+	if err != nil {
+		return err
+	}
+
+	// take the contents from the last hook and update files
+	hook = hooks[len(hooks)-1]
+	data, err = hook.Data.Get("out")
+	if err != nil {
+		return err
+	}
+
+	// copy file content to tar archive
+	_, err = io.Copy(tw, strings.NewReader(data.(string)))
+	if err != nil {
+		return err
+	}
+
+	return nil
+}