Rails, sessions-based authentication

api_data_authenticate_user looks like...

    def api_data_authenticate_user(username, password)
      # Authenticates a user account in Infusionsoft
      Thread.current[:api_conn].api_perform('DataService', 'authenticateUser', username, password)
    end

and [the relevant lines from] api_perform look like...

    def api_perform(class_type, method, *args)
      begin
        server = XMLRPC::Client.new3({'host' => @api_url, 'path' => "/api/xmlrpc", 'port' => 443, 'use_ssl' => true})
        result = server.call("#{class_type}.#{method}", @api_key, *args)
        .
        .
        .
      end
      return result
    end