blowfish/layouts/shortcodes/gallery.html

{{ $time := now.UnixNano }}
{{ $id := delimit (slice "gallery" .Ordinal $time) "-" }}

<div id="{{ $id }}">
  {{ .Inner }}
</div>

<script>
  $(document).ready(function () {
    $('#{{ $id }}').packery({
      percentPosition: true,
      gutter: 5,
      resize: true
    });
  })
</script>