app/views/comments/_comments.html.erb
<hr>
<h2>Comments</h2>
<% @post.comments.each do |comment| %>
<div class='panel panel-default'>
<div class='panel-body'>
<%= comment.body %>
<div class='author'>
Commented by: <%= comment.user.email %>
</div>
</div>
</div>
<% end %>
<%= form_for [@post, @post.comments.build] do |f| %>
<div class='form-group'>
<%= f.text_area :body, class: 'form-control' %>
</div>
<div class='actions'>
<%= f.submit "Save", class: 'btn btn-success' %>
</div>
<% end %>