Installation
First, on server01 install the nagios package. In a terminal enter:
sudo apt-get install nagios3 nagios-nrpe-plugin
You will be asked to enter a password for the nagiosadmin user. The user’s credentials are stored in /etc/nagios3/htpasswd.users. To change the nagiosadmin password, or add additional users to the Nagios CGI scripts, use the htpasswd that is part of the apache2-utils package.
For example, to change the password for the nagiosadmin user enter:
sudo htpasswd /etc/nagios3/htpasswd.users nagiosadmin
Configuration
- First, create a host configuration file for server02. Unless otherwise specified, run all these commands on server01. In a terminal enter:
sudo service nagios3 restart
In the above and following command examples, replace “server01”, “server02” 172.18.100.100, and 172.18.100.101 with the host names and IP addresses of your servers.
- Next, edit /etc/nagios3/conf.d/server02.cfg:
define host{ use generic-host ; Name of host template to use host_name server02 alias Server 02 address 172.18.100.101 } # check DNS service. define service { use generic-service host_name server02 service_description DNS check_command check_dns!172.18.100.101 } -
Restart the nagios daemon to enable the new configuration:
sudo service nagios3 restart
Check if your web site is up
You could use check_http to check your website is up on port 80, you could also using this plugin as well:
https://exchange.nagios.org/directory/Plugins/Websites,-Forms-and-Transactions/Check-website-response/details
You might encounter this error:
sudo service nagios3 restart
- It might happen if you did not install netcat.
- To install netcat,using the following command
sudo service nagios3 restart
sudo service nagios3 restart
If the out put is not /usr/bin/nc, you need to replace the netcat location in the check_website_response.sh script. In my case it is /bin/netcat.
I place my check_website_response.sh under /usr/lib/nagios/plugins
sudo service nagios3 restart
replace NETCAT=/usr/bin/nc with NETCAT=/bin/netcat
Restart the nagios server.
sudo service nagios3 restart
Done.