<div class="carousel-inner">

    <% @post.gallery_images.each do |i| %>
    <div class="item">
       <%= image_tag i.image.url, class: 'img-responsive' %>
    </div>
    <% end %>

</div>

<div class="carousel-inner">

    <% @post.gallery_images.each do |i| %>
    <div class="item active">
       <%= image_tag i.image.url, class: 'img-responsive' %>
    </div>
    <% end %>

</div>