nagios

Nagios monitors system health and sends out alerts.

Typically, you have a nagios master server which collects stats from remote clients. The master server will run nagios, while clients will run NRPE.

You will need an .htaccess file to access the data. You also need to create a user nagiosadmin to connect as.

The .htaccess file will need to be placed into two locations: /usr/share/nagios/htdocs/.htaccess and /usr/lib/nagios/cgi-bin/.

htpasswd -c /usr/share/nagios/auth.users nagiosadmin
chown nagios:nagios /usr/share/nagios/auth.users

AuthName "Nagios Access"
AuthType Basic
AuthUserFile /usr/share/nagios/auth.users
Require valid-user

net-analyzer/nagios-core apache2
net-analyzer/nagios-plugins nagios-ssh nagios-ping nagios-dns mysql

Add -D NAGIOS to Apache's conf.d file as well, to enable the web service.

Some config files in /etc/nagios may need their permissions adjusted so that Apache can have read access.

Verify that the configuration is correct:

nagios -v /etc/nagios/nagios.cfg

You can test an nrpe check directly from the nagios server to the client to verify it's working:

check_nrpe -H 192.168.56.2 -c check_uptime