Latest package is nagios3 – to install:
<code>sudo apt-get install nagios3
A good article on setup and config is here.
To restart the Nagios server after making config changes: sudo /etc/init.d/nagios3 restart
Resolving CGI auth issues
Part of the install instructions above told me to create a user ‘nagios’, but the default config is setup to allow ‘nagiosadmin’ access to monitor services. Accessing the wepages you get this:
<code>"It appears as though you do not have permission to view information for any of the hosts you requested... If you believe this is an error, check the HTTP server authentication requirements for accessing this CGI and check the authorization options in your CGI configuration file."</code>
To fix this, edit /etc/nagios3/cgi.cfg, and replace ‘nagiosadmin’ everywhere with ‘nagios’ (assuming the user you created was called ‘nagios’)