Set the CSRF token for Rails when doing Ajax requests

csrf-token.js

define( ['jquery'], function ( $ ) {
  var token = $( 'meta[name="csrf-token"]' ).attr( 'content' );

  $.ajaxSetup( {
    beforeSend: function ( xhr ) {
      xhr.setRequestHeader( 'X-CSRF-Token', token );
    }
  });

  return token; 
});

Can I ask you how to create this cookie in Rails? On ApplicationController maybe? On every NON-GET action?