Mod_status healthchecks

I’m moving HAProxy from a RHEL host to pfSense, like I had before. I made peace with the features I’m going to lose and workarounds I may have to resort to, but it’s one less host to maintain, it’s has a great GUI if a little cumbersome, but at least I won’t need a desktop anymore to edit it and backing up is a breeze.

With all of the new things I learned from compiling to writing my own config file to memory-tuning the thing, I had to start over setting up the new proxy ends in the GUI which had some interesting info, more like ideas, for instance the agent-based healthchecks: this appears to be some process that returns a simple string that tells HAProxy in more detail than otherwise what’s up with the server.

This sounds a lot like Apache httpd’s mod_status; it return a ton of info about the server for both human and machine consumption. It definitely is not a simple ASCII string though.

But, HAProxy has some scripting in its config, and transformations, and regex and the http-check expect so-and-so… so I’m wondering if somebody already tried/documented this?