From a1eeb872bfc97d8d856c164b2f79e6a7a83d47c6 Mon Sep 17 00:00:00 2001
From: Frederik Lindenaar <frederik@lindenaar.nl>
Date: Mon, 17 Oct 2016 18:44:33 +0200
Subject: [PATCH] added check_temperature plugin to monitor temperatures on a RaspberryPi
---
README.md | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
plugins/check_temperature | 272 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 331 insertions(+), 0 deletions(-)
create mode 100755 plugins/check_temperature
diff --git a/README.md b/README.md
index 0f5e5c8..46e93a9 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,8 @@ This repository contains the following scripts:
monitor multi-home and dual-stack (i.e. ipv4 and ipv6) servers.
* [check_otp](#check_otp)
plugin to monitor PrivacyIDEA (and LinOTP) OTP validation
+ * [check_temperature](#check_temperature)
+ plugin to monitor the temperature of a 1-wire sensor on a RaspberryPi
* [nagiosstatus](#nagiosstatus)
CGI-BIN script to report the status of nagios (to monitor nagios itself)
@@ -233,6 +235,63 @@ define service {
~~~
+<a name=check_temperature>plugins/check_temperature</a>
+-------------------------------------------------------
+Plugin (check) to monitor monitor the temperature using a sensor connected to a
+RaspberryPi. This implementation is specifically for the DS18B20 1-wire
+temperature sensor. Other methods and interfaces can be plugged in easily (just
+raise a request or provide a patch). For information on how to connect sensor
+to the RaspberryPi and to get it working please see [this Adafruit tutorial](
+https://learn.adafruit.com/adafruits-raspberry-pi-lesson-11-ds18b20-temperature-sensing).
+
+To enable the 1-wire interface support on the RaspberryPi one can use the
+command:
+~~~
+ sudo raspi-config nonint do_onewire 0
+~~~
+or use `raspi-config` in interactive mode (9. Advanced Options --> A9. 1-Wire).
+Please note that changing this requires a reboot.
+
+Installation for is straightforward, after installing the script on the server
+add the following to your Nagios `commands.cmd` configuration file:
+
+~~~
+# 'check_temperature' command definition to monitor a single temperature in C
+# parameters: warning (ARG1) and critical (ARG2) temperature in Celcius
+define command {
+ command_name check_temperature
+ command_line [install_path]/plugins/check_temperature -w $ARG1$ -c $ARG2$
+}
+
+# 'check_ftemperature' command definition to monitor a single temperature in F
+# parameters: warning (ARG1) and critical (ARG2) temperature in Farenheit
+define command {
+ command_name check_ftemperature
+ command_line [install_path]/plugins/check_temperature -F -w $ARG1$ -c $ARG2$
+}
+
+# 'check_temperature_sensor' command definition to monitor a single temperature in C
+# parameters: sensor serial (ARG1), warning (ARG2) and critical (ARG3) temperature in Celcius
+define command {
+ command_name check_temperature_sensor
+ command_line [install_path]/plugins/check_temperature -s $ARG1$ -w $ARG2$ -c $ARG3$
+}
+
+# 'check_ftemperature_sensor' command definition to monitor a single temperature in F
+# parameters: sensor serial (ARG1), warning (ARG2) and critical (ARG3) temperature in Farenheit
+define command {
+ command_name check_ftemperature_sensor
+ command_line [install_path]/plugins/check_temperature -F -s $ARG1$ -w $ARG2$ -c $ARG3$
+}
+
+~~~
+
+Make sure to replace `[install_path]/plugins` with the location of the script.
+
+Please run `check_temperature -h` after installation for an overview of the
+available command line options (e.g. to enable logging to a file).
+
+
<a name=nagiosstatus>cgi-bin/nagiosstatus.sh</a>
------------------------------------------------
Very simplistic CGI-BIN script that checkes whether nagios is still running and
diff --git a/plugins/check_temperature b/plugins/check_temperature
new file mode 100755
index 0000000..6d87bba
--- /dev/null
+++ b/plugins/check_temperature
@@ -0,0 +1,272 @@
+#! /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 <http://www.gnu.org/licenses/> 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]
+ })
--
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