Documentation ============= The upstream source does not include the documentation any more. Instead they want you to read it online, at: http://go.nagios.com/nagioscore/docs/ If you have questions about using/configuring nagios you should contact the nagios-users mailing list: nagios-users@lists.sourceforge.net Authentication ============== The default install ***TURNS OFF AUTHENTICATION*** The default apache2 configuration only allows access from private IP Addresses. This should be fine for the toy example setup by default install, but is unlikely to suffice for real usage. Look at /etc/nagios4/cgi.cfg and /etc/nagios4/apache2.conf. Default Install =============== After the default install of nagios-cgi, if apache2 is running you should be able to see it at: http://127.0.0.1/nagios4 Nagios will not run unless it has a service and a host to monitor, so the default Debian install is configured to verify localhost is up by pinging 127.0.0.1. Obviously this is not very useful, but it does allow a newbie to see what Nagios looks like. A typical Nagios configuration tends towards huge, where "huge" means it's so big syadmins usually resort to writing a tool that generates it. The default install is set up to read additional configuration files from /etc/nagios4/conf.d. This is the preferred place for packages to place their nagios files. Monitoring plugins ================== Debian has separate family of packages for Nagios plugins called monitoring-plugins. Nagios4 only depends on monitoring-plugins-basic but all should work. URL's ===== Nagios4 insists you hardwire URI's into it at compile time. Debian sets these hardwired URI's to: htmlurl=/nagios4 This is where it fetches images, css, and ancillary files from. cgiurl=/cgi-bin/nagios4 Nagios4's cgi programs live here. It would be nice if Nagios4 always respected these settings, but it doesn't. For example at times you will see it fetch .cgi from /nagios4/cgi-bin. In other words, internally Nagios4 uses a combination of relative and absolute URI's. The shipped /etc/nagios4/apache2.conf covers all possibilities. However, you don't have to put the web interface at http://site.com/nagios4. Putting at another URI (eg http://site.com/foobar) will work and it will stick in browsers URL bar, but it will still fetch some stuff from the hardwired URI's under the hood, and of course it will also use combinations of relative URL's combined with the hardwired ones and your new one, which creates a lot of possible paths. There is no easy solution to making this work beyond suck it and see - I'm just letting you know it is possible.