Rails display related posts by tags with images fr

Question

postI'm trying to retrieve related posts by tags by showing the attached image per related post, uploaded by using the carrierwave gem

Tags were written from scratch but similar to acts-as-taggable-on gem. Below solution picked from Rails count article per tag and related article by tag displays the related posts by title.

<% @posts.each do |post| %>

<% post.tags.each do |tag| %>

RELATED POSTS:
<% tag.posts.each do |related_post| %>
<%= link_to related_post.title + " , ", post %>
<% end %>
<% end %>
<% end %>

Now I want related posts to be displayed by image instead of title per above. Code displaying image for post is

<%= image_tag(post.cover.url(:thumb)) if post.cover? %>

How can I fit this in the RELATED POSTS above? I tried

<%= image_tag(related_post.cover.url(:thumb)) if post.cover? %>

but this throws:

NameError: undefined local variable or method 'related_post' for #<#:0x007fb67db38fb8>

Obviously related_post is not recorded in the carrierwave uploader model since it is different from the tags model. Any help please?