resources :people do
    collection do
      get 'image/:id', :to => "people#image", :as => 'image'
      get 'ranks', :to => "people#ranks", :as => 'ranks'
      get 'search/:search(.:format)', to: 'people#search'
    end
  end

<%= form_tag(people_search_path) do %>
  <%= text_field_tag :search %>
  <%= submit_tag 'Search' %>
<% end %>

undefined local variable or method `people_search_path' for #<#<Class:0x00007ff2afc59168>:0x00007ff2afc50f68>