Fastly ESI CSRF Token for Spree

application_controller.rb

...
  def csrf_meta_tags
    render layout: false
  end
...

csrf_meta_tags.html.haml

= csrf_meta_tags

csrf_meta_tags.rb

# Replace CSRF token with ESI
Deface::Override.new(virtual_path: 'spree/shared/_head',
                     name: 'csrf_token',
                     replace: "erb[loud]:contains('csrf_meta_tags')",
                     text: '<esi:include src="/csrf_meta_tags.html" />')

routes.rb

  get '/csrf_meta_tags' => 'application#csrf_meta_tags'