Nagios Support Forum

I need help in Monitoring Docker containers with Nagios.

You'll want to check out https://exchange.nagios.com/directory/P ... er/details if you haven't already.

To help us help you: What version of Core are you using? Was it compiled from source or installed from distro repos? On what OS/version is nagios running? cat /etc/*-release may be of use. Also, please give us as much info as you can about what you are trying to monitor in docker...like, what applications and metrics? Thanks!

I am using CentOS release 6.6 (Final) OS, Nagios core Version is 4.2.0.

You neglected to give us any information about what you are trying to monitor in docker. If you are running enough of the OS in docker, you should be able to monitor them just like any other OS, but we will need more information if we are going to be more specific.

Did you look at the plugin I suggested?

Also, I will note that 4.2.4 fixes a serious security hole, so you might want to look at upgrading: https://assets.nagios.com/downloads/nag ... ading.html

Yes, I tried to use that plugin getting error like NRPE: Unable to read output.

NRPE 3.0, Nagios-plugins -2.1.4

We have a NRPE troubleshooting document: https://assets.nagios.com/downloads/nag ... utions.pdf

It says it's for XI, but it's applicable to Core as well.

In addition to the trouble-shooting document, are you running NRPE through xinetd or stand-alone? If the second, did you allow it through the firewall? Did you add the server's IP into your allowed_from in your nrpe.cfg?

Also, can you upload as a file your /usr/local/nagios/var/objects.cache? Thanks!

running through xinetd service, Yes I've added server's IP into nrpe.cfg file.

If NRPE is running under xinetd, you will need to alter a different file to whitelist the Nagios XI machine. The file you want to be altering is usually located at /etc/xinetd.d/nrpe. Specifically, the only_from directive. You will also need to restart the xinetd service after changing this file.

there is no NRPE file in /etc/xinetd.d/ location