def initialize(config):
"""Do various initilization things.
:param config: a :class:`plumd.config.conf` instance
:type config: plumd.config.conf
"""
# set the configured timezone, from:
# http://stackoverflow.com/questions/6321160/python-logging-how-to-set-time-to-gmt
tz = config.get('tz')
if tz:
try:
os.environ['TZ'] = tz
time.tzset()
except Exception as e:
err = "unable to set timezone: {0} : {1}\n"
sys.stderr.write(err.format(tz, e))
sys.exit(1)
# add hostname metadata
if config.get('meta.hostname'):
meta = config.get('meta')
# meta is a list of single item {'key': 'value'} dicts
for entry in meta:
for key, val in entry.items():
if key == 'hostname':
err = "meta.hostname: hostname in meta already: {0} : {1}\n"
sys.stderr.write(err.format(val, config.path))
sys.exit(1)
meta.append({'hostname': plumd.util.get_hostname()})
config.set_conf('meta', meta)
return config
def get_config():
"""Returns a conf object - either from the default file or cmd line arg.
:rtype: plumd.config.conf
"""
descr = """plumd: measures system and service metrics."""
# get cli options - currently just the path to this instances config file
argp = argparse.ArgumentParser(description=descr)
argp.add_argument('--config', metavar='config', type=str,
nargs='?', default=plumd.DEFAULT_CONFIG_FILE,
help='main configuration file in yaml format')
args = argp.parse_args()
# get a simple configuration helper object
config = None
try:
config = plumd.config.Conf(args.config).defaults(plumd.DEFAULT_CONFIG)
except plumd.ConfigError as e:
sys.stderr.write("configuration failed to load: {0}\n".format(e))
sys.exit(1)
# ensure log level is known
llevel = config.get('log.level')
if llevel not in plumd.LOG_LEVELS:
llevels = " ".join(list(plumd.LOG_LEVELS.keys()))
sys.stderr.write("unkonwn log level: {0}\n".format(llevel))
sys.stderr.write("valid log levels are: {0}\n".format(llevels))
sys.exit(1)
# all done, return our config
return config
def get_plugins(config, log):
"""Returns a plugin loader object with plugins already started.
:param config: a :class:`plumd.config.conf` instance
:type config: plumd.config.conf
:param log: a structlog logging instance
:type log: structlog
:rtype: plumd.load.PluginLoader"""
# load reader and writer plugins and start
log.info("loading plugins")
psys = None
# several things can go wrong loading plugins
try:
psys = plumd.PluginLoader(log, config)
except plumd.PluginLoadError as e:
log.critical("plugin load failed: {0}".format(e))
sys.exit(1)
except plumd.ConfigError as e:
log.critical("invalid plugin config: {0}".format(e))
sys.exit(1)
except plumd.DuplicatePlugin as e:
log.critical("duplicate plugin: {0}".format(e))
sys.exit(1)
else:
log.info("plugins loaded")
time.sleep(random.randrange(int(config.get('delay.startup'))))
psys.start()
log.debug("main: plugins: {0}".format(psys))
# all done, return the PluginLoader object
return psys
def get_log(config):
"""Returns a configured logger.
:param config: a :class:`plumd.config.conf` instance
:type config: plumd.config.conf
:param src: all log entries generated are tagged with src=<src>
:type src: str
:rtype: structlog.logger
"""
# create logger
handler = logging.StreamHandler(sys.stdout)
formatter = logging.Formatter(config.get('log.format'))
handler.setFormatter(formatter)
stdlog = logging.getLogger()
stdlog.addHandler(handler)
stdlog.setLevel(plumd.LOG_LEVELS[config.get('log.level')])
return stdlog
