I know Nagios can monitor and alert on the content within a log file, but does anyone know of a plug-in, or other tool, that will monitor a log file for a particular string and then send the entire line in an email message where that match occured?
The stock check_log plugins is sort of… miserable; it uses ‘diff’ and processes the entire log, every time you run it, so it doesn’t scale well. At all.
ConSol Labs maintains an excellent log checking plugin that does exactly what you want:
It is listed on Nagios Exchange, but here is the direct link to the English version:
You have to run this through NRPE, or check_via_ssh (+ ssh keys), obviously.