I am suggest a module with Zabbix Client and Zabbix Proxy to monitoring NS of my clients, i dont programe for help with this, sorry
You can try install Adagios, a web interface to Nagios.
The Zabbix agent and proxy can be installed via rpm CentOS directly in nethserver without headaches. http://tecadmin.net/install-zabbix-agent-on-centos-rhel/#
Never did the installation in nethserver, however I do not see why not run smoothly.
I´m testing and its ok, but have necessary a config agent and open port 10050, if a module with zabbix agent with install packets, config zabbix_agent.conf and automatic open port 10050 in firewall, its the best!
yes, i agree… it’s on my (always more longer) to-do list from months… i hope to find time to do it…