#! /usr/bin/env python # # check_temperature - Nagios temperature check for DS18B20 sensor on RaspberryPi # # Version 1.0, latest version, documentation and bugtracker available at: # https://gitlab.lindenaar.net/scripts/nagios-plugins # # Copyright (c) 2016 Frederik Lindenaar # # This script is free software: you can redistribute and/or modify it under the # terms of version 3 of the GNU General Public License as published by the Free # Software Foundation, or (at your option) any later version of the license. # # This script is distributed in the hope that it will be useful but WITHOUT ANY # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR # A PARTICULAR PURPOSE. See the GNU General Public License for more details. # # You should have received a copy of the GNU General Public License along with # this program. If not, visit to download it. from sys import exit from os.path import basename, splitext from glob import glob from time import time, sleep from argparse import ArgumentParser as StandardArgumentParser, FileType, \ _StoreAction as StoreAction, _StoreConstAction as StoreConstAction import logging # Constants (no need to change but allows for easy customization) VERSION="1.0" PROG_NAME=splitext(basename(__file__))[0] PROG_VERSION=PROG_NAME + ' ' + VERSION SENSOR_SCALE=1000 SENSOR_DEV_DIR = '/sys/bus/w1/devices/' SENSOR_DEV_PREFIX = '28-' SENSOR_DEV_SUFFIX = '/w1_slave' SENSOR_READ_RETRIES=10 LOG_FORMAT='%(levelname)s - %(message)s' LOG_FORMAT_FILE='%(asctime)s - ' + LOG_FORMAT LOGGING_NONE=logging.CRITICAL + 10 NAGIOS_OK = ( 'OK', 0) NAGIOS_WARN = ( 'WARNING', 1) NAGIOS_CRITICAL = ( 'CRITICAL', 2 ) NAGIOS_UNKNOWN = ( 'UNKNOWN', 3 ) # Setup logging logging.basicConfig(format=LOG_FORMAT) logging.addLevelName(LOGGING_NONE, 'NONE') logger = logging.getLogger(PROG_NAME) logger.setLevel(logging.CRITICAL) ################[ wrapper to stop ArgumentParser from exiting ]################ # based on http://stackoverflow.com/questions/14728376/i-want-python-argparse-to-throw-an-exception-rather-than-usage/14728477#14728477 # the only way to do this is overriding the error method and throw and Exception class ArgumentParserError(Exception): pass class ArgumentParser(StandardArgumentParser): """ArgumentParser not exiting with non-Nagios format message upon errors""" def error(self, message): raise ArgumentParserError(message) ##################[ Action to immediately set the log level ]################## class SetLogLevel(StoreConstAction): """ArgumentParser action to set log level to provided const value""" def __call__(self, parser, namespace, values, option_string=None): logging.getLogger(PROG_NAME).setLevel(self.const) ####################[ Action to immediately log to a file ]#################### class SetLogFile(StoreAction): """ArgumentParser action to log to file (sets up FileHandler accordingly)""" def __call__(self, parser, namespace, values, option_string=None): super(SetLogFile, self).__call__(parser,namespace,values,option_string) formatter = logging.Formatter(LOG_FORMAT_FILE) handler = logging.FileHandler(values) handler.setFormatter(formatter) logger = logging.getLogger(PROG_NAME) logger.propagate = False logger.addHandler(handler) ############################################################################### def convert_celcius(temp_read): """Converts raw temperature sensore value to degrees Celcius""" return float(temp_read) / float(SENSOR_SCALE) CONVERT_CELCIUS = ( convert_celcius, 'C', 'Celcius' ) def convert_farenheit(temp_read): """Converts raw temperature sensore value to degrees Farenheit""" return float(temp_read * 9) / float(5 * SENSOR_SCALE) + 32.0 CONVERT_FARENHEIT = ( convert_farenheit, 'F', 'Farenheit' ) def isempty(string): """Checks whether string 'str' provided is unset or empty""" return string is None or len(string) == 0 def parse_args(): """Parse command line and get parameters from environment, if present""" # Setup argument parser, the workhorse gluing it all together parser = ArgumentParser( epilog='(*) by default the script will look for the first device that ' 'matches %s* in %s, if multiple entries are found -s or -f must ' 'be used to specify which sensor to read.' % (SENSOR_DEV_PREFIX, SENSOR_DEV_DIR), description='Nagios check plugin for 1-wire temp. sensor on RaspberryPi' ) parser.add_argument('-V', '--version',action="version",version=PROG_VERSION) pgroup = parser.add_mutually_exclusive_group(required=False) pgroup.add_argument('-C', '--celcius', action='store_const', dest='converter', const=CONVERT_CELCIUS, help='measure, critical and warn values in Celcius ' '(default)', default=CONVERT_CELCIUS) pgroup.add_argument('-F', '--farenheit',action='store_const', dest='converter', const=CONVERT_FARENHEIT, help='measure, critical and warn values in Farenheit') parser.add_argument('-w', '--warn', type=float, help='temperature for warning status') parser.add_argument('-c','--critical', type=float, help='temperature for critical status') parser.add_argument('-r', '--retries', type=int,default=SENSOR_READ_RETRIES, help='number of times to retry reading sensor data when' ' unstable (defaults to %d)' % SENSOR_READ_RETRIES) pgroup = parser.add_mutually_exclusive_group(required=False) pgroup.add_argument('-s', '--serial', help='(unique part of) temperature sensor serial (*)') pgroup.add_argument('-f', '--file', help='input file (or device) to obtain data from (*)') pgroup = parser.add_mutually_exclusive_group(required=False) pgroup.add_argument('-q', '--quiet', default=logging.CRITICAL, action=SetLogLevel, const=LOGGING_NONE, help='quiet (no output, only exit with exit code)') pgroup.add_argument('-v', '--verbose', help='more verbose output', action=SetLogLevel, const=logging.INFO) pgroup.add_argument('-d', '--debug', help='debug output (more verbose)', action=SetLogLevel, const=logging.DEBUG) parser.add_argument('-l', '--logfile', action=SetLogFile, help='send logging output to logfile') # parse arguments and post-process command line options args = parser.parse_args() # if we got here all seems OK return args def get_sensor_device_filename(args, dev_dir=SENSOR_DEV_DIR, prefix=SENSOR_DEV_PREFIX, suffix=SENSOR_DEV_SUFFIX): """Auto-determine sensor datafile name (unless args.file is set)""" if isempty(args.file): search_pat = dev_dir + ('/' if dev_dir[-1]!='/' else '') search_pat+= prefix + '*' if isempty(args.serial) else '*' + args.serial logger.debug('looking for sensors with search pattern %s', search_pat) device_folders = glob(search_pat) if len(device_folders) == 1: filename = device_folders[0] + suffix else: if len(device_folders) == 0: errmsg = 'no supported temperature sensors in %s' % dev_dir else: serials=map(lambda x: basename(x) if x.find(prefix)<0 else basename(x)[len(prefix):], device_folders) errmsg = 'found multiple temperature sensors (%s), please '\ 'specify which one to use' % ', '.join(serials) logger.critical(errmsg) raise ValueError(errmsg) else: filename = args.file logger.debug('using temperature sensor at %s', filename) return filename def read_sensor_raw(device_file): """Reads the raw data from the sensor device file, returns array of lines""" with open(device_file, 'r') as f: lines = f.readlines() logger.debug('Temperature sensor data read from %s: %s', f.name, lines) return lines def read_temp(device_file, converter=CONVERT_CELCIUS, maxretries=10): """Reads sensor data and converts it to desired unit, returns temperature""" lines = read_sensor_raw(device_file) tries = 1 while lines[0].strip()[-3:] != 'YES' and tries <= maxretries: tries += 1 sleep(0.2) logger.warn('Temperature sensor data not stable, reading once more') lines = read_temp_raw(device_file) if lines[0].strip()[-3:] != 'YES': errmsg = 'no stable temperature sensor data after %d tries' % tries else: equals_pos = lines[1].find('t=') if equals_pos == -1: errmsg = 'temperature sensor data format is not supported' else: temp_read = int(lines[1][equals_pos+2:]) temp = converter[0](temp_read) logger.debug('Temperature sensor value %d is %.2f%s', temp_read, temp, converter[1]) return temp, tries logger.critical(errmsg) raise ValueError(errmsg) def nagios_exit(status, message, data=None): """exit 'nagios-style', print status and message followed by perf. data""" if logger.isEnabledFor(logging.CRITICAL): if data is not None and len(data) > 0: perfdata=map(lambda (k,v): "'%s'=%s" %(k,v if not isinstance(v,list) else ';'.join(map(lambda x:'' if x is None else str(x),v))) ,data.iteritems()) perfstr = ' | ' + ' '.join(perfdata) else: perfstr = '' print 'Temperature %s: %s%s' % (status[0], message, perfstr) exit(status[1]) if __name__ == '__main__': try: args = parse_args() except ArgumentParserError as e: nagios_exit(NAGIOS_UNKNOWN,'error with setup: ' + e.message) except (KeyboardInterrupt, EOFError) as e: print nagios_exit(NAGIOS_UNKNOWN,'initialization aborted') try: starttime = time() devicefile = get_sensor_device_filename(args) temperature, tries = read_temp(devicefile, args.converter, args.retries) endtime = time() except (KeyboardInterrupt) as e: nagios_exit(NAGIOS_UNKNOWN,'temperature sensor read aborted by user') except (IOError, ValueError) as e: nagios_exit(NAGIOS_UNKNOWN,'temperature sensor read failed: %s' % e) elapse = endtime-starttime logger.info('Got temperature reading of %.2f degrees %s in %fs', temperature, args.converter[2], elapse) temp_unit = args.converter[1] message = 'current temperature is %.2f%s' % (temperature, temp_unit) if args.critical is not None and temperature > args.critical: nagiosresult = NAGIOS_CRITICAL message += ', above critical threshold %.2f%s'%(args.critical,temp_unit) elif args.warn is not None and temperature > args.warn: nagiosresult = NAGIOS_WARN message += ', above warning threshold %.2f%s' % (args.warn, temp_unit) else: nagiosresult = NAGIOS_OK nagios_exit(nagiosresult, message, { 'temperature': [ temperature, args.warn, args.critical, None, None], 'retries': [ tries-1, None, args.retries, 0, None ], 'time': [ '%f' % elapse, None, None, 0, None] })