app/controllers/robots_controller.rb
# frozen_string_literal: true
class RobotsController < ApplicationController
DEFAULT_FILENAME = 'config/robots.txt'
def robots
filename = "config/robots.#{subdomain}.txt" if subdomain && subdomain != 'www'
file_to_render = File.exist?(filename.to_s) ? filename : DEFAULT_FILENAME
render file: file_to_render, layout: false, content_type: 'text/plain'
end
private
def subdomain
request.subdomain.presence
end
end