Sunday 4 March 2012

Logfile tail the web way

Recently I needed something like web based equivalent of tail -f and tail -n commands, so I could display running tail or last N lines from specific log file. To avoid reinventing the wheel I started looking at previous works on-line and found some interesting bits here and there - one of the most useful being AJAX Logfile Tailer & Viewer, so I based my work on this one.

The trick is, that as far as it does exactly what I needed, this solution requires web server with PHP... and installing web server (not to mention PHP) is not really what I want on my logserver.

Mojolicious to the rescue!

Mojolicious is a very powerful Perl web framework that comes without bloat (almost unheard of these days!) - all you need is standard Perl interpreter and core Perl modules as they come preinstalled with your Linux distro and you can install Mojolicious - no other dependencies. On Debian systems installation is as simple as

apt-get install libmojolicious-perl

and we're up and running. Writing Mojolicious::Lite app is really simple and the best part is that it comes with it's own, built in web server (operating in several different modes if needed). Sounds like nice way to go - no dedicated web server on the machine, self-contained application, etc. One more thing - writing, testing and deploying the whole code to actual machine took less than 10 minutes!