Source code for faucet.valve_util

"""Utility functions for FAUCET."""

# Copyright (C) 2015 Brad Cowie, Christopher Lorier and Joe Stringer.
# Copyright (C) 2015 Research and Education Advanced Network New Zealand Ltd.
# Copyright (C) 2015--2019 The Contributors
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

import logging
from logging.handlers import WatchedFileHandler
import os
import signal
import sys
from functools import wraps

[docs]def kill_on_exception(logname): """decorator to ensure functions will kill ryu when an unhandled exception occurs""" def _koe(func): @wraps(func) def __koe(*args, **kwargs): try: func(*args, **kwargs) except: logging.getLogger(logname).exception( 'Unhandled exception, killing RYU') logging.shutdown() os.kill(os.getpid(), signal.SIGTERM) return __koe return _koe
[docs]def utf8_decode(msg_str): """Gracefully decode a possibly UTF-8 string.""" return msg_str.decode('utf-8', errors='replace')
[docs]def get_sys_prefix(): """Returns an additional prefix for log and configuration files when used in a virtual environment""" # Find the appropriate prefix for config and log file default locations # in case Faucet is run in a virtual environment. virtualenv marks the # original path in sys.real_prefix. If this value exists, and is # different from sys.prefix, then we are most likely running in a # virtualenv. Also check for Py3.3+ pyvenv. sysprefix = '' if (getattr(sys, 'real_prefix', sys.prefix) != sys.prefix or getattr(sys, 'base_prefix', sys.prefix) != sys.prefix): sysprefix = sys.prefix return sysprefix
_PREFIX = get_sys_prefix() # To specify a boolean-only setting, set the default value to a bool type. DEFAULTS = { 'FAUCET_CONFIG': ''.join(( _PREFIX, '/etc/faucet/faucet.yaml', ':', _PREFIX, '/etc/ryu/faucet/faucet.yaml')), 'FAUCET_CONFIG_STAT_RELOAD': False, 'FAUCET_LOG_LEVEL': 'INFO', 'FAUCET_LOG': _PREFIX + '/var/log/faucet/faucet.log', 'FAUCET_EVENT_SOCK': '', # Special-case, see get_setting(). 'FAUCET_EXCEPTION_LOG': _PREFIX + '/var/log/faucet/faucet_exception.log', 'FAUCET_PROMETHEUS_PORT': '9302', 'FAUCET_PROMETHEUS_ADDR': '', 'GAUGE_CONFIG': ''.join(( _PREFIX, '/etc/faucet/gauge.yaml', ':', _PREFIX, '/etc/ryu/faucet/gauge.yaml')), 'GAUGE_CONFIG_STAT_RELOAD': False, 'GAUGE_LOG_LEVEL': 'INFO', 'GAUGE_PROMETHEUS_ADDR': '', 'GAUGE_EXCEPTION_LOG': _PREFIX + '/var/log/faucet/gauge_exception.log', 'GAUGE_LOG': _PREFIX + '/var/log/faucet/gauge.log' } def _cast_bool(value): """Return True if value is a non-zero int.""" try: return int(value) != 0 except ValueError: return False
[docs]def get_setting(name, path_eval=False): """Returns value of specified configuration setting.""" default_value = DEFAULTS[name] result = os.getenv(name, default_value) # split on ':' and find the first suitable path if (path_eval and isinstance(result, str) and isinstance(default_value, str) and not isinstance(default_value, bool)): locations = result.split(":") result = None for loc in locations: if os.path.isfile(loc): result = loc break if result is None: result = locations[0] # Check for setting that expects a boolean result. if isinstance(default_value, bool): return _cast_bool(result) # Special default for FAUCET_EVENT_SOCK. if name == 'FAUCET_EVENT_SOCK': if result == '0': return '' if _cast_bool(result): return _PREFIX + '/var/run/faucet/faucet.sock' return result
[docs]def get_logger(logname, logfile, loglevel, propagate): """Create and return a logger object.""" stream_handlers = { 'STDOUT': sys.stdout, 'STDERR': sys.stderr, } try: if logfile in stream_handlers: logger_handler = logging.StreamHandler(stream_handlers[logfile]) else: logger_handler = WatchedFileHandler(logfile) except (PermissionError, FileNotFoundError) as err: # pytype: disable=name-error print(err) sys.exit(-1) logger = logging.getLogger(logname) log_fmt = '%(asctime)s %(name)-6s %(levelname)-8s %(message)s' logger_handler.setFormatter( logging.Formatter(log_fmt, '%b %d %H:%M:%S')) logger.addHandler(logger_handler) logger.propagate = propagate logger.setLevel(loglevel) return logger
[docs]def close_logger(logger): """Close all handlers on logger object.""" if logger is None: return for handler in list(logger.handlers): handler.close() logger.removeHandler(handler)
[docs]def dpid_log(dpid): """Log a DP ID as hex/decimal.""" return 'DPID %u (0x%x)' % (dpid, dpid)
[docs]def stat_config_files(config_hashes): """Return dict of a subset of stat attributes on config files.""" config_files_stats = {} for config_file in list(config_hashes.keys()): try: config_file_stat = os.stat(config_file) except OSError: continue config_files_stats[config_file] = ( config_file_stat.st_size, config_file_stat.st_mtime, config_file_stat.st_ctime) return config_files_stats