Problems installing nrpe on Ubuntu PCs

Support forum for Nagios Core, Nagios Plugins, NCPA, NRPE, NSCA, NDOUtils and more. Engage with the community of users including those using the open source solutions.
Locked
kCyborg
Posts: 4
Joined: Tue Mar 16, 2021 7:49 am

Problems installing nrpe on Ubuntu PCs

Post by kCyborg »

Hi guys.

First of all: I did a researh before asking the question but I could not find the answer to my problem :-(

Im begun to work on this new job administrating a network, and I decided that the services can be improved, so I did a research and find Nagios (a software that I have heard a lot in my college years) and I decided to install nagios to monitorize my server and PCs's stats and their services. I have a Proxmox server where all my servers live, so all the mentioned servers are Proxmoxs VMs.

So far so good, I installed Nagios core on a Debian 10 VM, I added some Windows and Debian hosts via (obviously) nrpe and all work flawlessly, but as soon as I try to install nrpe on a Ubuntu 18.10 the problems start.

The steps to install nrpe on a host are quite simple to follow:

Code: Select all

sudo apt-get update
sudo apt-get install nagios-nrpe-server monitoring-plugins

nano /etc/nagios/nrpe.cfg
And change:

Code: Select all

server_address=127.0.0.1, 192.168.0.225 (IP of the host)
allowed_hosts=127.0.0.1,::1,192.168.0.220 (IP of the Nagios core server)

Code: Select all

nano /etc/nagios/nrpe_local.cfg
And add:

Code: Select all

command[check_root]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /
command[check_ping]=/usr/lib/nagios/plugins/check_ping -H 192.168.0.225 -w 100.0,20% -c 500.0,60% -p 5
command[check_ssh]=/usr/lib/nagios/plugins/check_ssh -4 192.168.0.225
command[check_http]=/usr/lib/nagios/plugins/check_http -I 192.168.0.225
command[check_apt]=/usr/lib/nagios/plugins/check_apt
Then just restart the nrpe service:

Code: Select all

sudo /etc/init.d/nagios-nrpe-server restart 
[ ok ] Restarting nagios-nrpe-server (via systemctl): nagios-nrpe-server.service.
But when I try on a server:

Code: Select all

sudo /etc/init.d/nagios-nrpe-server status
I get this answer:

Code: Select all

* nagios-nrpe-server.service - Nagios Remote Plugin Executor
   Loaded: loaded (/lib/systemd/system/nagios-nrpe-server.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Tue 2021-03-16 13:06:48 UTC; 32s ago
     Docs: http://www.nagios.org/documentation
  Process: 8291 ExecStopPost=/bin/rm -f /var/run/nagios/nrpe.pid (code=exited, status=0/SUCCESS)
  Process: 8273 ExecStart=/usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -f $NRPE_OPTS (code=exited, status=1/FAILURE)
 Main PID: 8273 (code=exited, status=1/FAILURE)

Mar 16 13:06:48 TeamSpeak systemd[1]: Started Nagios Remote Plugin Executor.
Mar 16 13:06:48 TeamSpeak nrpe[8273]: Starting up daemon
Mar 16 13:06:48 TeamSpeak nrpe[8273]: bad addr or host: 127.0.0.1,192.168.0.221 (Name or service not known)
Mar 16 13:06:48 TeamSpeak systemd[1]: nagios-nrpe-server.service: Main process exited, code=exited, status=1/FAILURE
Mar 16 13:06:48 TeamSpeak systemd[1]: nagios-nrpe-server.service: Failed with result 'exit-code'.
The thing is that when I edit the /etc/nagios/nrpe.cfg
And change:

Code: Select all

server_address=127.0.0.1
Letting just the local IP addres and deleting the host IP the service run flawlessly, but obviosly when from the Nagios core server I try to check I get a refuse connection error

Code: Select all

sudo /usr/lib/nagios/plugins/check_nrpe -H 192.168.0.221
connect to address 192.168.50.221 port 5666: Connection refused
connect to host 192.168.50.221 port 5666: Connection refused
I tried to not use an IP but the hostname itself, and I got the exact same anser when I try the restart and then the status check

So... What am I doing wrong? I guess it's something simple that Im not able to see, but I cant find where is my error, can you guys help me?
kCyborg
Posts: 4
Joined: Tue Mar 16, 2021 7:49 am

Re: Problems installing nrpe on Ubuntu PCs

Post by kCyborg »

It was a firewall problem...

@admins if you wanna can delete this thread
benjaminsmith
Posts: 5324
Joined: Wed Aug 22, 2018 4:39 pm
Location: saint paul

Re: Problems installing nrpe on Ubuntu PCs

Post by benjaminsmith »

It was a firewall problem...
@admins if you wanna can delete this thread
Sounds good. We'll lock this one.

Have a great weekend!

Benjamin
Nagios Support Team
As of May 25th, 2018, all communications with Nagios Enterprises and its employees are covered under our new Privacy Policy.

Be sure to check out our Knowledgebase for helpful articles and solutions!
Locked