| # The source code is from following Python documentation: |
| # https://docs.python.org/2/howto/logging-cookbook.html#network-logging |
| |
| # Classes in this file are used to create a simple TCP socket-based logging |
| # receiver. The receiver listens to default logging port (9020) and save log to |
| # any given log configuration, e.g., a local file. Once the receiver is running, |
| # client can add a logging handler to write log to the receiver with following |
| # sample code: |
| # socketHandler = logging.handlers.SocketHandler('localhost', |
| # logging.handlers.DEFAULT_TCP_LOGGING_PORT) |
| # logging.getLogger().addHandler(socketHandler) |
| |
| import ctypes |
| import pickle |
| import logging |
| import multiprocessing |
| import select |
| import SocketServer |
| import struct |
| import time |
| |
| import common |
| from autotest_lib.client.bin import utils |
| |
| class LogRecordStreamHandler(SocketServer.StreamRequestHandler): |
| """Handler for a streaming logging request. |
| |
| This basically logs the record using whatever logging policy is |
| configured locally. |
| """ |
| |
| def handle(self): |
| """ |
| Handle multiple requests - each expected to be a 4-byte length, |
| followed by the LogRecord in pickle format. Logs the record |
| according to whatever policy is configured locally. |
| """ |
| while True: |
| chunk = self.connection.recv(4) |
| if len(chunk) < 4: |
| return |
| slen = struct.unpack('>L', chunk)[0] |
| chunk = self.connection.recv(slen) |
| while len(chunk) < slen: |
| chunk = chunk + self.connection.recv(slen - len(chunk)) |
| obj = self.unpickle(chunk) |
| record = logging.makeLogRecord(obj) |
| self.handle_log_record(record) |
| |
| |
| def unpickle(self, data): |
| """Unpickle data received. |
| |
| @param data: Received data. |
| @returns: unpickled data. |
| """ |
| return pickle.loads(data) |
| |
| |
| def handle_log_record(self, record): |
| """Process log record. |
| |
| @param record: log record. |
| """ |
| # if a name is specified, we use the named logger rather than the one |
| # implied by the record. |
| if self.server.logname is not None: |
| name = self.server.logname |
| else: |
| name = record.name |
| logger = logging.getLogger(name) |
| # N.B. EVERY record gets logged. This is because Logger.handle |
| # is normally called AFTER logger-level filtering. If you want |
| # to do filtering, do it at the client end to save wasting |
| # cycles and network bandwidth! |
| logger.handle(record) |
| |
| |
| class LogRecordSocketReceiver(SocketServer.ThreadingTCPServer): |
| """Simple TCP socket-based logging receiver. |
| """ |
| |
| allow_reuse_address = 1 |
| |
| def __init__(self, host='localhost', port=None, |
| handler=LogRecordStreamHandler): |
| if not port: |
| port = utils.get_unused_port() |
| SocketServer.ThreadingTCPServer.__init__(self, (host, port), handler) |
| self.abort = 0 |
| self.timeout = 1 |
| self.logname = None |
| self.port = port |
| |
| |
| def serve_until_stopped(self): |
| """Run the socket receiver until aborted.""" |
| print 'Log Record Socket Receiver is started.' |
| abort = 0 |
| while not abort: |
| rd, wr, ex = select.select([self.socket.fileno()], [], [], |
| self.timeout) |
| if rd: |
| self.handle_request() |
| abort = self.abort |
| print 'Log Record Socket Receiver is stopped.' |
| |
| |
| class LogSocketServer: |
| """A wrapper class to start and stop a TCP server for logging.""" |
| |
| process = None |
| port = None |
| |
| @staticmethod |
| def start(**kwargs): |
| """Start Log Record Socket Receiver in a new process. |
| |
| @param kwargs: log configuration, e.g., format, filename. |
| |
| @raise Exception: if TCP server is already running. |
| """ |
| if LogSocketServer.process: |
| raise Exception('Log Record Socket Receiver is already running.') |
| server_started = multiprocessing.Value(ctypes.c_bool, False) |
| port = multiprocessing.Value(ctypes.c_int, 0) |
| LogSocketServer.process = multiprocessing.Process( |
| target=LogSocketServer._start_server, |
| args=(server_started, port), |
| kwargs=kwargs) |
| LogSocketServer.process.start() |
| while not server_started.value: |
| time.sleep(0.1) |
| LogSocketServer.port = port.value |
| print 'Log Record Socket Server is started at port %d.' % port.value |
| |
| |
| @staticmethod |
| def _start_server(server_started, port, **kwargs): |
| """Start the TCP server to receive log. |
| |
| @param server_started: True if socket log server is started. |
| @param port: Port used by socket log server. |
| @param kwargs: log configuration, e.g., format, filename. |
| """ |
| # Clear all existing log handlers. |
| logging.getLogger().handlers = [] |
| if not kwargs: |
| logging.basicConfig( |
| format='%(asctime)s - %(levelname)s - %(message)s') |
| else: |
| logging.basicConfig(**kwargs) |
| |
| tcp_server = LogRecordSocketReceiver() |
| print('Starting TCP server...') |
| server_started.value = True |
| port.value = tcp_server.port |
| tcp_server.serve_until_stopped() |
| |
| |
| @staticmethod |
| def stop(): |
| """Stop Log Record Socket Receiver. |
| """ |
| if LogSocketServer.process: |
| LogSocketServer.process.terminate() |
| LogSocketServer.process = None |
| LogSocketServer.port = None |