NRPE (Nagios Remote Plugin Executor) is used for executing Nagios plugins on remote client systems. In previous article we had described about installation of Nagios Server on Ubuntu operating system. This article will help you to install NRPE on Ubuntu 17.10, 16.04 LTS, 14.04, 12.04 & LinuxMint 18/17 systems.
Step 1 – Install NRPE and Plugins
NRPE is available under default apt repositories of Ubuntu systems. Execute the following command to install it
sudo apt-get update sudo apt-get install nagios-nrpe-server nagios-plugins
Step 2 – Configure NRPE Client
In NRPE configuration, first we need to nrpe to which nagios servers it accepts requests, For example your nagios server ip is 192.168.1.100, then add this ip to allowed hosts list. Edit NRPE configuration file /etc/nagios/nrpe.cfg and make changes like
allowed_hosts=127.0.0.1,192.168.1.100
we can add more Nagios servers in allowed hosts by comma separated list.
Now restart NRPE service. Now its ready to listen to requests from Nagios server
sudo /etc/init.d/nagios-nrpe-server restart
Step 3 – Verify Connection to NRPE from Nagios
Let’s log in to your Nagios server and verify that your Nagios server can communicate with NRPE service properly. Execute following command from Nagios server plugin directory, and we are assuming that your nrpe client-server IP is 192.168.1.11.
check_nrpe -H 192.168.1.11 NRPE v2.15
The output “NRPE v2.15” shows that Nagios server successfully communicated with NRPE.
Step 4 – Add Check Commands in NRPE
All the services check commands with the nagios plugins packages, which is by default installed in /usr/lib/nagios/plugins/ for 32 bit systems. Default installation adds few commands in configuration file. Add more commands as per your requirements like below
vim /etc/nagios/nrpe.cfg
command[check_users ]=/usr/lib/nagios/plugins/check_users -w 5 -c 10 command[check_load ]=/usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20 command[check_hda1 ]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1 command[check_zombie_procs ]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z command[check_total_procs ]=/usr/lib/nagios/plugins/check_procs -w 150 -c 200
Step 5 – Start/Stop NRPE Service
Use following commands to start, stop or restart NRPE service. Each time we make any changes in configuration file required to restart service
sudo /etc/init.d/nagios-nrpe-server stop sudo /etc/init.d/nagios-nrpe-server start sudo /etc/init.d/nagios-nrpe-server restart
Hello,
I have a 2 Ubuntu 17.04 Server, 1 with nagios installed and NRPE client (plugin) installed, the other with NRPE Server installed.
When I run check nrpe from the NRPE client, I have this result.
[email protected]:/etc/nagios3/conf.d$ /usr/lib/nagios/plugins/check_nrpe -H 192.168.36.144 -c check_load
CHECK_NRPE: Error – Could not connect to 192.168.36.144: Connection reset by peer
[email protected]:/etc/nagios3/conf.d$ tail /var/log/syslog
Aug 8 05:39:06 Server1 systemd[1]: Started Clean php session files.
Aug 8 05:46:38 Server1 dhclient[948]: DHCPREQUEST of 192.168.36.137 on ens33 to 192.168.36.254 port 67 (xid=0x483d61d1)
Aug 8 05:46:38 Server1 dhclient[948]: DHCPACK of 192.168.36.137 from 192.168.36.254
Aug 8 05:46:38 Server1 dhclient[948]: bound to 192.168.36.137 — renewal in 807 seconds.
Aug 8 05:49:55 Server1 check_nrpe: Error: Could not complete SSL handshake with 192.168.36.144: rc=-1 SSL-error=5
Aug 8 05:54:15 Server1 systemd[1682]: Time has been changed
Aug 8 05:54:15 Server1 systemd[1]: Time has been changed
Aug 8 05:54:15 Server1 systemd[1]: apt-daily.timer: Adding 7h 35min 17.413926s random time.
Aug 8 05:54:15 Server1 systemd[1]: snapd.refresh.timer: Adding 3h 28min 6.371800s random time.
Aug 8 05:56:09 Server1 check_nrpe: Error: Could not complete SSL handshake with 192.168.36.144: rc=-1 SSL-error=5
On the NRPE Server side, these are the logs that are shown.
[email protected]:~$ tail /var/log/syslog
Aug 8 05:35:23 Server3 dhclient[878]: DHCPACK of 192.168.36.144 from 192.168.36.254
Aug 8 05:35:23 Server3 dhclient[878]: bound to 192.168.36.144 — renewal in 770 seconds.
Aug 8 05:46:07 Server3 kernel: [28496.550944] perf: interrupt took too long (3452 > 3148), lowering kernel.perf_event_max_sample_rate to 57750
Aug 8 05:48:13 Server3 dhclient[878]: DHCPREQUEST of 192.168.36.144 on ens33 to 192.168.36.254 port 67 (xid=0x2aed808)
Aug 8 05:48:13 Server3 dhclient[878]: DHCPACK of 192.168.36.144 from 192.168.36.254
Aug 8 05:48:13 Server3 dhclient[878]: bound to 192.168.36.144 — renewal in 824 seconds.
Aug 8 05:49:55 Server3 nrpe[15350]: Error: Request packet version was invalid!
Aug 8 05:49:55 Server3 nrpe[15350]: Could not read request from client 192.168.36.137, bailing out…
Aug 8 05:56:09 Server3 nrpe[15357]: Error: Request packet version was invalid!
Aug 8 05:56:09 Server3 nrpe[15357]: Could not read request from client 192.168.36.137, bailing out…
Any ideas why the SSL Handshake is failing? I’m just started to learn linux nagios and I’m quite lost.
It looks you didn’t allowed Nagios server in NRPE configuration. Please check Step 2.
Also, make sure NRPE port is accessible to Nagios server.
Hi Rahul,
Actually, I did.
I have added the server address where the “nagios-nrpe-server” is installed (which is the target server).
192.168.36.137 – Is the server where nagios is and the “nagios-nrpe-plugin” is installed.
Please see image below via link, I am being blocked by your website when posting the content of the nrpe.cfg
!ApePyXZrHH4NhvETTo34dpVlLigTcg
Hi Rahul,
For Nagios Server I am choosing ” Amazon Linux AMI 2017.03.0 (HVM), SSD Volume Type – ami-c58c1dd3 ”
And I try to add CentOs, Ubuntu, Windows Servers. It taking only Centos and AWS Linux servers, But I try to ADD Ubuntu And Window I am getting Error:
[[email protected] nagios]# vim nagios.cfg
[[email protected] nagios]# service nagios restart
Running configuration check… CONFIG ERROR! Restart aborted. Check your Nagios configuration.
If I uncomment the Ubuntu Path in Nagios.cfg file (Ubuntu Server :#cfg_file=/etc/nagios/servers/ProdAppEmpi.cfg), It’s Working.
[[email protected] nagios]# vim nagios.cfg
[[email protected] nagios]# service nagios restart
Running configuration check…done.
Stopping nagios: done.
Starting nagios: done.
Here My question is, does we choosing Centos for Nagios server it Accept only centos Server for Remote monitoring. And If we choose Ubuntu Does it accept only Ubuntu servers.
We do have any Option to add all types of NRPE (Remote Monitor Servers) to one Nagios Server(either centos r Ubuntu r windows..etc..) ?????
Hi Prabhu,
You can install Nagios on any OS and it will monitor everything. There will be some issue with ProdAppEmpi.cfg configuration file. Can you please show me this file content?
HI Rahul..i have been trying to install nagios for monitoring purpose. I have got the nagios dashbord also but the hosts i am adding are not reflecting. Kindly suggest which are the necessary confg files where i need to make changes? Also tell me how to configure email and sms alerts in nagios?
check_nrpe did not work until I added the /usr/lib/nagios/plugins into the environments file. Overall nice work.
I am getting this below error.
cpu_load
CRITICAL 04-23-2016 12:59:11 0d 21h 50m 33s 3/3 (No output on stdout) stderr: execvp(/usr/lib/nagios/plugins/check_nrpe, …) failed. errno is 2: No such file or directory
Myserver is centos4.0.8 and client is ubuntu
I have done all the steps i am able to communicate to client. i am getting the check_load also from server end.but it is not displayed on nagios web page.
This is all client side rick.
The problem with this explanation, every explanation so far, is that it isn’t clear weather your talking about the Nagios server or Client side configuration.