There is plenty of software for monitoring how server performs and whether servers are correctly up and running. There is probably no Debian Linux admin who didn't already worked or at least tried Nagios and Mointor to monitor and notify whether server is unreachable or how server services operate. Nagios and Munin are play well together to prevent possible upcoming problems with Web / Db / E-mail services or get notify whether they are completely inaccessible. One similar "next-generation" and less known software is Icanga.
The reason, why to use Icinga instead of Nagios is more features a list of what does Icinga supports more than Nagios is on its site here
I recently heard of it and decided to try it myself. To try Icanga I followed Icanga's install tutorial on Wiki.Icanga.Org here
In Debian Wheezy, Icinga is already part of official repositories so installing it like in Squeeze and Lenny does not require use of external Debian BackPorts repositories.
1. Install Icinga pre-requirement packages
debian:# apt-get --yes install php5 php5-cli php-pear php5-xmlrpc php5-xsl php5-gd php5-ldap php5-mysql
2. Install Icanga-web package
debian:~# apt-get --yes install icinga-web
Here you will be prompted a number of times to answer few dialog questions important for security, as well as fill in MySQL server root user / password as well as SQL password that will icinga_web mySQL user use.
….
Setting up icinga-idoutils (1.7.1-6) …
dbconfig-common: writing config to /etc/dbconfig-common/icinga-idoutils.conf
granting access to database icinga for icinga-idoutils@localhost: success.
verifying access for icinga-idoutils@localhost: success.
creating database icinga: success.
verifying database icinga exists: success.
populating database via sql… done.
dbconfig-common: flushing administrative password
Setting up icinga-web (1.7.1+dfsg2-6) …
dbconfig-common: writing config to /etc/dbconfig-common/icinga-web.confCreating config file /etc/dbconfig-common/icinga-web.conf with new version
granting access to database icinga_web for icinga_web@localhost: success.
verifying access for icinga_web@localhost: success.
creating database icinga_web: success.
verifying database icinga_web exists: success.
populating database via sql… done.
dbconfig-common: flushing administrative passwordCreating config file /etc/icinga-web/conf.d/database-web.xml with new version
database config successful: /etc/icinga-web/conf.d/database-web.xmlCreating config file /etc/icinga-web/conf.d/database-ido.xml with new version
database config successful: /etc/icinga-web/conf.d/database-ido.xml
enabling config for webserver apache2…
Enabling module rewrite.
To activate the new configuration, you need to run:
service apache2 restart
`/etc/apache2/conf.d/icinga-web.conf' -> `../../icinga-web/apache2.conf'
[ ok ] Reloading web server config: apache2 not running.
root password updates successfully!
Basedir: /usr Cachedir: /var/cache/icinga-web
Cache already purged!
3. Enable Apache mod_rewrite
debian:~# a2enmod rewrite
debian:~# /etc/init.d/apache2 restart
4. Icinga documentation files
Some key hints on Enabling some more nice Icinga features are mentioned in Icinga README files, check out, all docs files included with Icinga separate packs are into:
debian:~# ls -ld *icinga*/
drwxr-xr-x 3 root root 4096 Jun 3 10:48 icinga-common/
drwxr-xr-x 3 root root 4096 Jun 3 10:48 icinga-core/
drwxr-xr-x 3 root root 4096 Jun 3 10:48 icinga-idoutils/
drwxr-xr-x 2 root root 4096 Jun 3 10:48 icinga-web/
debian:~# less /usr/share/doc/icinga-web/README.Debian
debian:~# less /usr/share/doc/icinga-idoutils/README.Debian
5. Configuring Icinga
Icinga configurations are separated in two directories:
debian:~# ls -ld *icinga*
drwxr-xr-x 4 root root 4096 Jun 3 10:50 icinga
drwxr-xr-x 3 root root 4096 Jun 3 11:07 icinga-web
>
etc/icinga/ – (contains configurations files for on exact icinga backend server behavior)
/etc/icinga-web – (contains all kind of Icinga Apache configurations)
Main configuration worthy to look in after install is /etc/icinga/icinga.cfg.
6. Accessing newly installed Icinga via web
To access just installed Icinga, open in browser URL – htp://localhost/icinga-web
7. Monitoring host services with Icinga (NRPE)
As fork of Nagios. Icinga has similar modular architecture and uses number of external plugins to Monitor external host services list of existing plugins is on Icinga's wiki here.
Just like Nagios Icinga supports NRPE protocol (Nagios Remote Plugin Executor). To setup NRPE, nrpe plugin from nagios is used (nagios-nrpe-server).
To install NRPE on any of the nodes to be tracked;
debian: ~# apt-get install –yes nagios-nrpe-server
…
Then to configure NRPE edit /etc/nagios/nrpe_local.cfg
Once NRPE is supported in Icinga, you can install on Windows or Linux hosts NRPE clients like in Nagios to report on server processes state and easily monitor if server disk space / load or service is in critical state.
