Yeah, I know nagios is old and (sometimes) ugly. And I wanted something new and modern, this is why I even tried Icinga. Otherwise, nagios would be already running here and monitoring my servers.
It is not so much about features, I have a rather simple setup here:
A few web servers, 2 RDBs, a NoSQL, a postfix. Plus I have to write some checks on my own for our docker setup (these are very specific checks, e.g. how often did the container restart within an hour, etc). Over the time this might be hundred containers or so, but nothing special at all.
My far most obstacles here is the documentation (as said before). Maybe it is due to a lot of fresh releases recently. But while this might be great that this product is driven forward with a lot of development, having an outdated documentation is useless for a new user like me. Pretty sure, an experienced user can handle this.
As mentioned above, the docs for director / working with agents took me already a few hours, just to figure out, how to do it with the current release (this specific documentation page is from 2017!).
The missing monitoring package in Debian added some hours as well.
The auto-generated nginx configuration does not work with the routing of the web backend (I got very nice, animated 404 on every route, means it loads all the css, js, etc. but everything was a 404).
So I got back to apache although I would prefer a small nginx server over a huge apache monster.
And so on… Somehow I run into a lot of different problems here and it is sometimes a bit frustrating.
So, if I knew this before, I would have been using a Ubuntu server (maybe the monitoring module is part of the web package there) and I would have been using apache in first place, this would have saved me a day at least.
Tutorials on the internet older than a year are pretty much useless (at least when it comes to installation, initial setup/configuration). Not sure if your book is useful if the development is so fast.
Anyway, thank you for your help.
Have a great weekend.