snippet.rb

<%= form_tag search_movies_path, :method => 'get', class: "navbar-form", role: "search" do %>
<%= text_field_tag :search, params[:search], class: "form-control" %>
<%= submit_tag "Search", name: nil, class: "btn btn-default" %>

# I needed a search method in the corresponding movies controller.rb

 def search
  @movies = Movie.search(params[:search])
 end

# Then I created a search view search.html.erb

class="row">
  <% @movies.each do |movie| %>
  
class="col-sm-6 col-md-3">
    
class="thumbnail">
     <%= link_to (image_tag movie.image.url(:poster), class: 'image'), movie %>
   </div>
  
 <% end %>
</div>