Maybe/app/controllers/concerns/authentication.rb

module Authentication
  extend ActiveSupport::Concern

  included do
    before_action :set_request_details
    before_action :authenticate_user!
  end

  class_methods do
    def skip_authentication(**options)
      skip_before_action :authenticate_user!, **options
    end
  end

  private
    def authenticate_user!
      if session_record = Session.find_by_id(cookies.signed[:session_token])
        Current.session = session_record
      else
        if self_hosted_first_login?
          redirect_to new_registration_url
        else
          redirect_to new_session_url
        end
      end
    end

    def create_session_for(user)
      session = user.sessions.create!
      cookies.signed.permanent[:session_token] = { value: session.id, httponly: true }
      session
    end

    def self_hosted_first_login?
      Rails.application.config.app_mode.self_hosted? && User.count.zero?
    end

    def set_request_details
      Current.user_agent = request.user_agent
      Current.ip_address = request.ip
    end
end