Display images from DB in a form_for RoR - ruby-on-rails

Question

I'm trying to create an update form that would modify ( add or remove ) images related to a product. Each product has many images , each image belongs to a product.
When a user wants to modify a product , the idea is that all the images related to the product displayed and the user decides whether to add more or remove them. My problem is I do not know how to make the images appear. I can only make it show the link.
edit.html.erb
<%- model_class = Product -%>
<div class="page-header">
<h1><%=t '.title', :default => [:'helpers.titles.edit', 'Edit %{model}'], :model => model_class.model_name.human.titleize %></h1>
</div>
<%= render :partial => 'form' %>
_form.html.erb
<%= form_for #product, :html => { :class => "form-horizontal product" } do |f| %>
<% if #product.errors.any? %>
<div id="error_expl" class="panel panel-danger">
<div class="panel-heading">
<h3 class="panel-title"><%= pluralize(#product.errors.count, "error") %> prohibited this product from being saved:</h3>
</div>
<div class="panel-body">
<ul>
<% #product.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
</div>
<% end %>
<div class="control-group">
<%= f.label :name, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :name, :class => 'form-control' %>
</div>
<%= error_span(#product[:name]) %>
</div>
<div class="control-group">
<%= f.label :price, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :price, :class => 'form-control' %>
</div>
<%= error_span(#product[:price]) %>
</div>
<div class="control-group">
<%= f.label :stock, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :stock, :class => 'form-control' %>
</div>
<%= error_span(#product[:stock]) %>
</div>
<div class="control-group">
<%= f.label :tipo, :class => 'control-label' %>
<div class="controls">
<%= f.text_field :tipo, :class => 'form-control' %>
</div>
<%= error_span(#product[:tipo]) %>
</div>
<p> <hr> </p>
<%= f.fields_for :images do |builder| %>
<%= render 'image_fields', f: builder %>
<% end %>
<%= link_to_add_fields "Add Question", f, :images %>
<p> <hr> </p>
<%= f.submit nil, :class => 'btn btn-primary' %>
<%= link_to t('.cancel', :default => t("helpers.links.cancel")),
products_path, :class => 'btn btn-default' %>
<% end %>
_image_fields.html.erb
<fieldset>
<%= f.label :link, "Imagen" %><br />
<div class="col-xs-6 col-md-3">
<a href="#" class="thumbnail">
<img src="<%= Here I want to introduce the link %>" alt="...">
</a>
</div>
<%= f.check_box :_destroy %>
<%= f.label :_destroy, "Remove Imagen" %>
</fieldset>
products_controller.rb
class ProductsController < ApplicationController
before_action :set_product, only: [:show, :edit, :update, :destroy]
before_action :build_image, only: [:edit]
private
# Use callbacks to share common setup or constraints between actions.
def set_product
#product = Product.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def product_params
params.require(:product).permit(:name, :price, :stock, :tipo, images_attributes: [ :link ])
end
def build_image
#images = #product.images.build
end
end