Dynamic HAProxy backends

HAProxy is one of very few pieces of software that are truly a joy to use. It’s written in C, it’s reliable, fast, secure and versatile. I’ve been using it for a number of years now for all kinds of purposes and its ability to inspect and manipulate HTTP requests is one of the features I use most often.

Rebuilding software RAID without mdadm.conf

Rebuilding software RAID array is very easy when you have your mdadm.conf file at hand, but when you find yourself in a situation without backup of that little config file, e.g. after reinstalling the system or when your migrate disks to the new server, it can be a bit daunting.

How to remove VirtFS like a boss

Recently I was unfortunate to witness huge filesystem loop on a cPanel server that was caused by combination of VirtFS and Idera’s Server Backup software (previously known as R1soft CDP backup). To cut the chase, I had to disable and remove VirtFS for all users on the server.

Fixing timeout between Nginx and PHP-FPM

In case you’ve set up Nginx as reverse proxy for PHP-FPM and you have very slow or complex PHP script that executes for quite some time, you’ve probably seen an 504 gateway time-out error. This is pretty common error, but in most cases people are barking at the wrong tree and they’re having difficulties finding out which timeout directive is the right one for their scenario.

Exim ACL for blocking certain senders

If you’re in a need for fast and simple solution to block certain senders directly on Exim mail server, you’re in luck. Couple of weeks back I needed to blacklist a spammer on a relay mail server, so that I could take my time and carefully trace the origin server/script from where the spam was being sent.