| # Copyright 2015 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """The discovery server used to register clients. |
| |
| The discovery server is started by the host controller and allows the clients |
| to register themselves when they start. Authentication of the client controllers |
| is based on an OTP passed to the client controller binary on startup. |
| """ |
| |
| import logging |
| import threading |
| import xmlrpclib |
| import SimpleXMLRPCServer |
| |
| #pylint: disable=relative-import |
| import common_lib |
| |
| |
| class DiscoveryServer(object): |
| """Discovery server run on the host.""" |
| |
| def __init__(self): |
| self._expected_clients = {} |
| self._rpc_server = None |
| self._thread = None |
| |
| def _RegisterClientRPC(self, otp, ip): |
| """The RPC used by a client to register with the discovery server.""" |
| assert otp in self._expected_clients |
| cb = self._expected_clients.pop(otp) |
| cb(ip) |
| |
| def RegisterClientCallback(self, otp, callback): |
| """Registers a callback associated with an OTP.""" |
| assert callable(callback) |
| self._expected_clients[otp] = callback |
| |
| def Start(self): |
| """Starts the discovery server.""" |
| logging.debug('Starting discovery server') |
| self._rpc_server = SimpleXMLRPCServer.SimpleXMLRPCServer( |
| (common_lib.SERVER_ADDRESS, common_lib.SERVER_PORT), |
| allow_none=True, logRequests=False) |
| self._rpc_server.register_function( |
| self._RegisterClientRPC, 'RegisterClient') |
| self._thread = threading.Thread(target=self._rpc_server.serve_forever) |
| self._thread.start() |
| |
| def Shutdown(self): |
| """Shuts the discovery server down.""" |
| if self._thread and self._thread.is_alive(): |
| logging.debug('Shutting down discovery server') |
| self._rpc_server.shutdown() |
