added check_temperature plugin to monitor temperatures on a RaspberryPi

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