ssh vs nrpe

[BanditBBS]

So here is another related question.....I sort of like the idea of not running nrpe under xinetd and using the daemon instead. What are the pros/cons to doing that? Anyone have a thought on that?

[jolson]

So here is another related question.....I sort of like the idea of not running nrpe under xinetd and using the daemon instead. What are the pros/cons to doing that? Anyone have a thought on that?

It really comes down to what xinetd provides, quoted from http://linux.die.net/man/8/xinetd:

So far, the only reason for the existence of a super-server was to conserve system resources by avoiding to fork a lot of processes which might be dormant for most of their lifetime. While fulfilling this function, xinetd takes advantage of the idea of a super-server to provide features such as access control and logging.

If you are not concerned about the added functionality of xinetd, nrpe can be compiled very easily without it:

First, we need to install NRPE - I will use version 2.15.
I used the following guide as a point of reference: http://nagios.sourceforge.net/docs/nrpe/NRPE.pdf.
I will assume that NRPE is being compiled on Nagios 4.x.

1. Download the tarball and extract it in your /tmp directory.

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cd /tmp && wget http://sourceforge.net/projects/nagios/files/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz/download && tar xfz download && cd nrpe*

Setup the 'nagios' user.

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useradd nagios && passwd nagios

2. Install NRPE pre-requisites.

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yum install -y mod_ssl openssl-devel gcc make openssl perl

3. Configure and make NRPE. This will create the /usr/local/nagios directory, which is where NRPE will be located.

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bash configure && make all && make install

4. Make the NRPE config directory, and setup the example config file.

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mkdir /usr/local/nagios/etc ; cp sample-config/nrpe.cfg /usr/local/nagios/etc/nrpe.cfg ; chown -R nagios:nagios /usr/local/nagios/etc

5. Open port 5666 in your firewall (if you intend on using NRPE for active checks). The rule below limits access to a particular source IP.

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iptables -A INPUT -s <nagiosserverip> -p tcp -m tcp --dport 5666 -m state --state NEW,ESTABLISHED -j ACCEPT && service iptables save

6. At this point, NRPE is ready to start.

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/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

7. Ensure that NRPE is up and running.

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ps -ef | grep nrpe | grep -v grep

#the output of this command should show one instance of NRPE running on the server.

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/usr/local/nagios/libexec/check_nrpe -H 127.0.0.1

Notes:
To have NRPE start on boot, consider adding an entry similar to the following to /etc/rc.local:

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echo "/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d" >> /etc/rc.local

If you already have a working NRPE configuration, you can probably remove xinetd and follow steps 7-8:

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yum remove xinetd
/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

[BanditBBS]

jolson - Really appreciate that in depth reply

Some of the servers won't have xinetd installed and since we are a hosting company, I really want to install as few items as possible on customer's machines. And since some won't have xinetd I'd just rather standardize for us as running as daemon. So I think my design as done and time to proceed with the install.

Leave this open and I'll update once I am done with my automation method for anyone else that may be interested.

[abrist]

Great! As far as the age old nrpe vs. check_by_ssh discussion goes:

[WillemDH]

Leave this open and I'll update once I am done with my automation method for anyone else that may be interested.

I'm most certainly interested how you are planning to do this. Go bandit..

[abrist]

We shall indeed leave this open.

[BanditBBS]

Hey WillemDH and whoever, linked is a web page of mine detailing how I did everything on my end. This is working awesomely!

Feel free to close this thread now if you'd like...people can PM me if they have questions

http://www.bandits-home-on-the-web.com/ ... date-nrpe/