class ExtendedSimpleOption(SimpleOption):
"""
Extends the SimpleOption class to allow other checks to occur at script prologue and epilogue.
- nagios reporting
- checking if running on the designated HA host
- locking on a file
The prologue should be called at the start of the script; the epilogue at the end.
"""
def __init__(self, options, run_prologue=True, excepthook=None, **kwargs):
"""Initialise.
If run_prologue is True (default), we immediately execute the prologue.
Note that if taking a lock is requested (default), and the lock cannot be
acquire for some reason, the program will exit,
"""
options_ = _merge_options(options)
super(ExtendedSimpleOption, self).__init__(options_, **kwargs)
self.nagios_reporter = None
self.lockfile = None
if run_prologue:
self.prologue()
if not excepthook:
sys.excepthook = self.critical_exception_handler
else:
sys.excepthook = excepthook
self.log = fancylogger.getLogger()
def prologue(self):
"""Checks the options given for settings and takes appropriate action.
See _merge_options for the format.
- if nagios_report is set, creates a SimpleNagios instance and prints the report.
- if ha is set, checks if running on the correct host, set the appropriate nagios message and bail if not.
- if locking_filename is set, take a lock. If the lock fails, bork and set the nagios exit accordingly.
"""
# bail if nagios report is requested
self.nagios_reporter = SimpleNagios(
_cache=self.options.nagios_check_filename,
_report_and_exit=self.options.nagios_report,
_threshold=self.options.nagios_check_interval_threshold,
_cache_user=self.options.nagios_user,
_world_readable=self.options.nagios_world_readable_check,
)
# check for HA host
if self.options.ha and not proceed_on_ha_service(self.options.ha):
self.log.warning(
"Not running on the target host %s in the HA setup. Stopping.",
self.options.ha)
self.nagios_reporter.ok("Not running on the HA master.")
sys.exit(NAGIOS_EXIT_OK)
if not self.options.disable_locking and not self.options.dry_run:
self.lockfile = TimestampedPidLockfile(
self.options.locking_filename,
threshold=self.options.nagios_check_interval_threshold * 2)
lock_or_bork(self.lockfile, self.nagios_reporter)
self.log.info("%s has started", _script_name(sys.argv[0]))
def _epilogue(self):
if not self.options.disable_locking and not self.options.dry_run:
release_or_bork(self.lockfile, self.nagios_reporter)
def epilogue(self, nagios_message, nagios_thresholds=None):
"""Run at the end of a script, quitting gracefully if possible."""
if nagios_thresholds is None:
nagios_thresholds = {}
self._epilogue()
nagios_thresholds['message'] = nagios_message
self.nagios_reporter._eval_and_exit(**nagios_thresholds)
self.log.info("%s has finished",
_script_name(sys.argv[0])) # may not be reached
def ok(self, nagios_message):
"""Run at the end of a script and force an OK exit."""
self._epilogue()
self.nagios_reporter.ok(nagios_message)
def warning(self, nagios_message):
"""Run at the end of a script and force a Warning exit."""
self._epilogue()
self.nagios_reporter.warning(nagios_message)
def critical(self, nagios_message):
"""Run at the end of a script and force a Critical exit."""
self._epilogue()
self.nagios_reporter.critical(nagios_message)
def unknown(self, nagios_message):
"""Run at the end of a script and force a Unknown exit."""
self._epilogue()
self.nagios_reporter.unknown(nagios_message)
def make_exit_map(self, ok=0, warn=1, crit=2, unkn=3):
"""Make a mapping of exit functions."""
return {
ok: self.ok,
warn: self.warning,
crit: self.critical,
unkn: self.unknown,
}
def critical_exception_handler(self, tp, value, traceback):
"""
Run at the end of a script and force a Critical exit.
This function is meant to be used as sys.excepthook
"""
self.log.exception("unhandled exception detected: %s - %s", tp, value)
self.log.debug("traceback %s", traceback)
message = "Script failure: %s - %s" % (tp, value)
self.critical(message)
class ExtendedSimpleOption(SimpleOption):
"""
Extends the SimpleOption class to allow other checks to occur at script prologue and epilogue.
- nagios reporting
- checking if running on the designated HA host
- locking on a file
The prologue should be called at the start of the script; the epilogue at the end.
"""
def __init__(self, options, run_prologue=True, excepthook=None, **kwargs):
"""Initialise.
If run_prologue is True (default), we immediately execute the prologue.
Note that if taking a lock is requested (default), and the lock cannot be
acquire for some reason, the program will exit,
"""
options_ = _merge_options(options)
super(ExtendedSimpleOption, self).__init__(options_, **kwargs)
self.nagios_reporter = None
self.lockfile = None
if run_prologue:
self.prologue()
if not excepthook:
sys.excepthook = self.critical_exception_handler
else:
sys.excepthook = excepthook
self.log = fancylogger.getLogger()
def prologue(self):
"""Checks the options given for settings and takes appropriate action.
See _merge_options for the format.
- if nagios_report is set, creates a SimpleNagios instance and prints the report.
- if ha is set, checks if running on the correct host, set the appropriate nagios message and bail if not.
- if locking_filename is set, take a lock. If the lock fails, bork and set the nagios exit accordingly.
"""
# bail if nagios report is requested
self.nagios_reporter = SimpleNagios(_cache=self.options.nagios_check_filename,
_report_and_exit=self.options.nagios_report,
_threshold=self.options.nagios_check_interval_threshold,
_cache_user=self.options.nagios_user,
_world_readable=self.options.nagios_world_readable_check,
)
# check for HA host
if self.options.ha and not proceed_on_ha_service(self.options.ha):
self.log.warning("Not running on the target host %s in the HA setup. Stopping." % (self.options.ha,))
self.nagios_reporter.ok("Not running on the HA master.")
sys.exit(NAGIOS_EXIT_OK)
if not self.options.disable_locking and not self.options.dry_run:
self.lockfile = TimestampedPidLockfile(self.options.locking_filename,
threshold=self.options.nagios_check_interval_threshold * 2)
lock_or_bork(self.lockfile, self.nagios_reporter)
self.log.info("%s has started" % (_script_name(sys.argv[0])))
def _epilogue(self):
if not self.options.disable_locking and not self.options.dry_run:
release_or_bork(self.lockfile, self.nagios_reporter)
def epilogue(self, nagios_message, nagios_thresholds=None):
"""Run at the end of a script, quitting gracefully if possible."""
if nagios_thresholds is None:
nagios_thresholds = {}
self._epilogue()
nagios_thresholds['message'] = nagios_message
self.nagios_reporter._eval_and_exit(**nagios_thresholds)
self.log.info("%s has finished" % (_script_name(sys.argv[0]))) # may not be reached
def ok(self, nagios_message):
"""Run at the end of a script and force an OK exit."""
self._epilogue()
self.nagios_reporter.ok(nagios_message)
def warning(self, nagios_message):
"""Run at the end of a script and force a Warning exit."""
self._epilogue()
self.nagios_reporter.warning(nagios_message)
def critical(self, nagios_message):
"""Run at the end of a script and force a Critical exit."""
self._epilogue()
self.nagios_reporter.critical(nagios_message)
def unknown(self, nagios_message):
"""Run at the end of a script and force a Unknown exit."""
self._epilogue()
self.nagios_reporter.unknown(nagios_message)
def make_exit_map(self, ok=0, warn=1, crit=2, unkn=3):
"""Make a mapping of exit functions."""
return {
ok: self.ok,
warn: self.warning,
crit: self.critical,
unkn: self.unknown,
}
def critical_exception_handler(self, tp, value, traceback):
"""
Run at the end of a script and force a Critical exit.
This function is meant to be used as sys.excepthook
"""
self.log.exception("unhandled exception detected: %s - %s", tp, value)
self.log.debug("traceback %s", traceback)
message = "Script failure: %s - %s" % (tp, value)
sys.exc_clear()
self.critical(message)
