CLI to get binaries from a docker image with multi arch support

have a look at the README.md to see how it works.

Bootstrap a CLI program to copy binaries from multi arch images

Signed-off-by: Gianluca Arbezzano <gianarb92@gmail.com>

cmd/getbinariesfromquay/tar/untar.go

@@ -0,0 +1,48 @@
+package tar
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+func Untar(dst string, r io.Reader) error {
+	gzr, err := gzip.NewReader(r)
+	if err != nil {
+		return err
+	}
+	defer gzr.Close()
+	tr := tar.NewReader(gzr)
+
+	for {
+		header, err := tr.Next()
+		switch {
+		case err == io.EOF:
+			return nil
+		case err != nil:
+			return err
+		case header == nil:
+			continue
+		}
+		target := filepath.Join(dst, header.Name)
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if _, err := os.Stat(target); err != nil {
+				if err := os.MkdirAll(target, 0755); err != nil {
+					return err
+				}
+			}
+		case tar.TypeReg:
+			f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
+			if err != nil {
+				return err
+			}
+			if _, err := io.Copy(f, tr); err != nil {
+				return err
+			}
+			f.Close()
+		}
+	}
+}