def md5_digest_for_file_at_path(file_path) do
    File.stream!(file_path, [:read, :binary], 1024 * 1024)
    |> Stream.chunk(1)
    |> Enum.reduce(
      :crypto.hash_init(:md5),
      fn(chunk, acc) ->
        :crypto.hash_update(acc, hd(chunk))
      end)
    |> :crypto.hash_final
    |> Base.encode16
    |> String.downcase
end