Nagios Plugin for the OneWire temperature sensors

This is a working, but super simple Nagios plugin to monitor a single OneWire temperature sensor.

In order to make sure this plugin works, you will need to make sure digitemp is configured and can connect to a sensor.

• First install digitemp: #> yum install digitemp
• Second, connect your USB OneWire sensor to your nagios box. I am using VMware and used USB pass-though to expose it to my nagios server
• Run digitemp to init a config file. My USB adapter is a DS9097U so this is the syntax: #> digitemp_DS9097U -i -s /dev/ttyUSB0 -c digitemp.conf
• Your sensors should be found and listed both in the command output and in the newly created config file
• Check to see what sensor is the one you want to verify on - you can have several but the check_onewire_temp only supports one
• Once you identify the sensor, test getting the temperature for it: #> digitemp_DS9097U -t 0 -q -c ./digitemp.conf
• Move your config file to /etc/digitemp.conf
• Edit check_onewire_temp to have the correct sensor
• Run check_onewire_temp as root to verify it works: #> ./check_onewire_temp OK: Current Temp: 73.40 | temp=73.40,75,80
• Copy check_onewire_temp to your plugins directory (e.g. /usr/lib64/nagios/plugins)
• Create a nagios service and command to run the plugin: define service { use generic-service host_name localhost service_description Room Temp check_command check_onewire_temp notification_period workhours } define command { command_name check_onewire_temp command_line $USER1$/check_onewire_temp }
• Add the user nagios is running as to the dialup group; this group has access to the USB devices. This is probably probably the user "nagios".
• Check nagios to verify your new config is working: #> nagios -v nagios.conf
• Restart nagios. This is required because we updated the user's group membership and that change needs to available for the current nagios process. #> service nagios restart
• Check the nagios web portal for the results.

Items To Do:

• Take the sensor as a command-line argument
• Take the warning and critical temperatures as command-line arguments