feat(image-build): add the ability to build images (#1672)

api/archive/tar.go

@@ -0,0 +1,36 @@
+package archive
+
+import (
+	"archive/tar"
+	"bytes"
+)
+
+// TarFileInBuffer will create a tar archive containing a single file named via fileName and using the content
+// specified in fileContent. Returns the archive as a byte array.
+func TarFileInBuffer(fileContent []byte, fileName string) ([]byte, error) {
+	var buffer bytes.Buffer
+	tarWriter := tar.NewWriter(&buffer)
+
+	header := &tar.Header{
+		Name: fileName,
+		Mode: 0600,
+		Size: int64(len(fileContent)),
+	}
+
+	err := tarWriter.WriteHeader(header)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = tarWriter.Write(fileContent)
+	if err != nil {
+		return nil, err
+	}
+
+	err = tarWriter.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	return buffer.Bytes(), nil
+}