How to Install Nagios on Ubuntu 18.04 Bionic Easy Guide

Nagios Ubuntu 18.04 - Adding User and Groups

3. After to Add nagios User and Groups
   Create the nagios User:

   useradd nagios

   Make the nagios Group:

   groupadd nagios

   Add the nagios user to the group:

   /usr/sbin/usermod -G nagios nagios

   Create a new nagcmd group for allowing external commands to be submitted through the web interface:

   groupadd nagcmd

   Add both the nagios & apache users to the Group:

   usermod -a -G nagcmd nagios

   usermod -a -G nagcmd www-data

   Last Achieve the SuperUser Session:

   exit