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#1
Nagios... lots of documentation, no howtos.
Posted by Arthur on Wed 5 Jul 2006 at 02:43
I spent much of yesterday getting nagios2 running properly and actually doing something useful. Gotta say I like it, but the documentation, while copius, forces a steep learning curve. If I'd had no previous experience with host/service monitors, I might have torn out some hair.
I searched around the web, found a bunch of "do this, then do that" kinds of howtos, but nothing that satisfactorily explained, in one swell foop, the relationships between the various components and configurations. The article here at d-a.org wasn't any better or worse than the rest... but no, I ain't gonna write one any time soon.
Hint, if you're about to install Nagios2 with NRPE: most of the remote checks you'll want to perform will require that you use check_nrpe_1arg rather than check_nrpe. Perhaps because I was fatigued at the time, I spent half an hour figuring that one out. It'd be nice if the Debian package nagios-nrpe-server had a few more checks configured out-of-the-box, but they aren't hard to put together.
Another hint, if you're installing nagios on a host whose Apache HTTP Server is running suEXEC: if you're doing a good administrator job, the .deb installation will almost certainly put things outside of suEXEC's document root. Future updates will continue to look to those unhappy places. My approach, which might be as wrong as dating outside your species: I created a vhost whose only purpose is to run nagios2, moved the CGI apps to that vhost's ScriptAlias directory, moved the /usr/share/nagios2/htdocs/ contents into that vhost's DocumentRoot directory, then symlinked the original directories to that vhost's corresponding directories. With any luck at all, future upgrades will work without any additional labor. I hope.
Now if I could just get a VRML plugin to work in Firefox, I could have some impressive 3-D maps to show off...
... I don't have much reason to believe that I'm going to give it the required effort.
I searched around the web, found a bunch of "do this, then do that" kinds of howtos, but nothing that satisfactorily explained, in one swell foop, the relationships between the various components and configurations. The article here at d-a.org wasn't any better or worse than the rest... but no, I ain't gonna write one any time soon.
Hint, if you're about to install Nagios2 with NRPE: most of the remote checks you'll want to perform will require that you use check_nrpe_1arg rather than check_nrpe. Perhaps because I was fatigued at the time, I spent half an hour figuring that one out. It'd be nice if the Debian package nagios-nrpe-server had a few more checks configured out-of-the-box, but they aren't hard to put together.
Another hint, if you're installing nagios on a host whose Apache HTTP Server is running suEXEC: if you're doing a good administrator job, the .deb installation will almost certainly put things outside of suEXEC's document root. Future updates will continue to look to those unhappy places. My approach, which might be as wrong as dating outside your species: I created a vhost whose only purpose is to run nagios2, moved the CGI apps to that vhost's ScriptAlias directory, moved the /usr/share/nagios2/htdocs/ contents into that vhost's DocumentRoot directory, then symlinked the original directories to that vhost's corresponding directories. With any luck at all, future upgrades will work without any additional labor. I hope.
Now if I could just get a VRML plugin to work in Firefox, I could have some impressive 3-D maps to show off...
... I don't have much reason to believe that I'm going to give it the required effort.
Comments on this Entry
Hello,
there is a warning written at the very beginning of the official documentation called Advice for Beginners. There is a good reason why it is there.
When I started with Nagios, it was terrible for me too. That's the truth. I was too searching web for some resources but then I realised that the documentation is so good that I did not need any extra resources and was able to start my first running monitoring system with Nagios. I realised that no extra documentation is needed. The task of configuring Nagios differs from one environment (eg. company network) to another. Thus it is really hard to write some "how-tos" about Nagios.
The only thing you can do to improve your capabilities of setting Nagios up is to read it's documentation slowly and properly. And that's it.
--
mjf
[ Parent | Reply to this comment ]
Uh-huh. I read through the entire pile of documentation twice before I reached for apt-get -- first a skim to become familiar with the author's terminology and the basic concepts of nagios2, then a thorough read for understanding.
It was morning when I first sat in front of a computer, but it wasn't this morning. This first exposure to Nagios was not my first exposure to host/network monitoring software, either.
I read the "Advice for Beginners" first, and in it the author states, "Nagios is quite powerful and flexible, but unfortunately its not very friendly to newbies. Why? Because it takes a lot of work to get it installed and configured properly."
No, that's not why it's unfriendly. Nagios is actually a simple enough thing, and easily enough configured once you get your head wrapped around it. The unfriendliness is in the documentation, which is quite detailed but is written as though the reader already has Nagios experience.
And that's it.
Have a nice day.
It was morning when I first sat in front of a computer, but it wasn't this morning. This first exposure to Nagios was not my first exposure to host/network monitoring software, either.
I read the "Advice for Beginners" first, and in it the author states, "Nagios is quite powerful and flexible, but unfortunately its not very friendly to newbies. Why? Because it takes a lot of work to get it installed and configured properly."
No, that's not why it's unfriendly. Nagios is actually a simple enough thing, and easily enough configured once you get your head wrapped around it. The unfriendliness is in the documentation, which is quite detailed but is written as though the reader already has Nagios experience.
And that's it.
Have a nice day.
[ Parent | Reply to this comment ]
I was unhappy with the Debian packages so I used the source code instead. The source offered more information about the configuration than with the default package, which seemed geared towards a quick installation rather than a comprehensive one. I'd recommend getting the source if only for the added help.
I found the online documentation man-pagey: straight-forward and to the point. I'd have to agree with the comment above about it beeing very good, but nagios is a complex tool that requires involved planning to implement correctly. In addition to the online documentation, the config files are commented and reading them sped up my first installation immensely.
After I had a basic working installation, I downloaded the latest HEAD version of the plugins rather than relying on the package and picked up a few more on the Nagios plugin site. I also found 'fruity', a nagios2 web-based configuration application which helped streamline my configuration files and give me a better overall view of what was happening with different hosts. Most of the time I use good ol' vi to add checks, but using fruity did help with dependencies and other features.
I haven't had the time to configure SNMP with it yet, or any of the passive checks but they're on the task list.
I found the online documentation man-pagey: straight-forward and to the point. I'd have to agree with the comment above about it beeing very good, but nagios is a complex tool that requires involved planning to implement correctly. In addition to the online documentation, the config files are commented and reading them sped up my first installation immensely.
After I had a basic working installation, I downloaded the latest HEAD version of the plugins rather than relying on the package and picked up a few more on the Nagios plugin site. I also found 'fruity', a nagios2 web-based configuration application which helped streamline my configuration files and give me a better overall view of what was happening with different hosts. Most of the time I use good ol' vi to add checks, but using fruity did help with dependencies and other features.
I haven't had the time to configure SNMP with it yet, or any of the passive checks but they're on the task list.
[ Parent | Reply to this comment ]
Btw, I've just set up everything to get running 3d status map under Firefox on a Debian testing box.
If you are interested, the first you have to do is download the .deb package. It says it was build for Ubuntutututu, but works fine on mine too.
Then install it, and then restart firefox. Take into account that it requires some extra apps, like java and to have GLX running (which means you have to have a 3d accel card) but well, I works :D
Links:
http://freewrl.sourceforge.net/download.html
http://freewrl.sourceforge.net/faq.html#ChapterLinux
Note: if when you restart firefox, It still doesn't working, you should manually link the FreeWRL plugin:
http://plugindoc.mozdev.org/linux.html#FreeWRL
Hope you find it useful!
DererK
If you are interested, the first you have to do is download the .deb package. It says it was build for Ubuntutututu, but works fine on mine too.
Then install it, and then restart firefox. Take into account that it requires some extra apps, like java and to have GLX running (which means you have to have a 3d accel card) but well, I works :D
Links:
http://freewrl.sourceforge.net/download.html
http://freewrl.sourceforge.net/faq.html#ChapterLinux
Note: if when you restart firefox, It still doesn't working, you should manually link the FreeWRL plugin:
http://plugindoc.mozdev.org/linux.html#FreeWRL
Hope you find it useful!
DererK
[ Parent | Reply to this comment ]