Category: Blog

A quick guide to install the normal Nagios via apt-get on an Raspberry PI using the standard Raspbian OS.

– Preliminary; I have bought 2 Raspberry PI’s version B with 512MB RAM. The first is going to be used for Nagios monitoring of my home appliances which has grown to an incredible 45 devices. I’ve been reading through a lot of blogs describing how to compile the Nagios from bottom-up. The 1st RPI also servers as a portal server for my guest wifi, not that I have that many guests, but I wanted to make som fun to. The second RPI is going to be used as an Ubiquiti Unifi server compiled from scratch with the soft-floating Raspbian image and Mongodb, more on this in a later article.

I took a different approach, as I wanted to make the install as simple as possible, so I’ve used the common software found through apt-get. And yes I do know Nagios is not the latest version, but I do not care about as it is running a decent version 3.4.1.

Some things to consider before going down this path:

• Make an static IP, this makes it easier to reach.
• Enable SSH from the install screen

Now let’s install (all this is done via SSH as my RP is headless), I do assume you have installed the Raspbian image on the SD-card, plugged in the network cable,SD-card and power)

1. apt-get update
2. apt-get upgrade (now the RPI is up to date but might take some time)
3. apt-get install nagios
4. It will ask you for an password for nagiosadmin.

Now all done 🙂 You can login to http://ip-of-your-server/nagios3  using nagiosadmin and the password you issued.

If you have encountered some Nagios installations before, be aware the files you need to use are not in the usual spots as described on Nagios.org

• /etc/nagios3 – this is your primary folder  where e.g. commands.cfg resides.
• /etc/nagios3/conf.d/ – this is the folder for all your config files. I used these for the basic monitoring tasks.
• /etc/nagios-plugins  – home of all the native plugins like http_check

I needed to check http status of some surveillance cams which I have choosen to monitor on other ports than the normal port 80 (web).
For this to be succesfull you will have to edit /etc/nagios-plugins/config/http.cfg and insert following $ARG$ to the end of the line like this;

# ‘check_http’ command definition
define command{
        command_name    check_http
        command_line    /usr/lib/nagios/plugins/check_http -H ‘$HOSTADDRESS$’ -I ‘$HOSTADDRESS$’ ‘$ARG1$’
        }

Then make another file for these devices, I’ve used services.cfg

define service{
        use             generic-service         ; Inherit default values from a template
        host_name               name-of-your-machine
        service_description     HTTP:PORT
        check_command   check_http!-p 10000 ;with 10000 as the port you want to monitor for http service
}

Presumably you have a host file named hostname.cfg with following basic input

define host {
use             generic-host
host_name      name-of-your-machine
address         192.168.1.2
}

Then save all your work and service nagios3 restart and refresh your browser.