How I Use Nagios
I have been using Nagios extensively to monitor infrastructure that I am interested in for about 10 years now, and each time I build a net-new Nagios monitoring system I version the configuration. I am up to Generation 4 now which includes:
- Approx 75 hosts at the moment
- Approx 130 service checks
- Service checks for:
- Generic TCP services (Tor ORPorts for example)
- Ping checks (v4 and v6)
- HTTP/HTTPS service checks (include cert expiry)
- Other TCP services like SMTP, SMTPS, IMAP, IMAPS, POP3, and POP3S
- NRPE-based host checks like total processes and disk space
- DNS service checks (are all masters serving all zones they are supposed to be)
- XMPP server checks
- Custom Alerts:
- SMS alerts on certain hosts using nagios-twilio
- Email alerts include the output of
mtr --show-ips --report --report-wide --aslookup -4 <host>
OS and Packages
Previously I’ve always run the Debian-included packages for Nagios, however those packages are stuck at Nagios v3.x and v4 has some improvements that I’ve been wanting to use for a long time. Recently when moving my main Nagios system to DigitalOcean I chose to build Nagios from source instead of using the Debian packages.
I have stored all of my Nagios configurations in git for several years now. Before they were stored in git I stored them in subversion which I was able to convert over to a git repo. This makes it really easy to replicate any changes (commits) over to other Nagios systems.
I manage the contents of
/etc/nagios3 on Debian, which includes
conf.d where all of my custom config is stored. Now that I’m using a custom-compiled version I instead manage
/usr/local/nagios/etc in git.