prepering to install nagios core

$ sudo apt-add-repository ppa:ondrej/php
$ sudo apt-get -y upgrade && apt-get -y update
$ sudo apt install -y wget build-essential apache2 php apache2-mod-php7.0 php-gd libgd-dev sendmail unzip openssl libssl-dev lynx mailutils
$ sudo useradd nagios
$ sudo groupadd nagcmd
$ sudo usermod -a -G nagcmd nagios
$ sudo usermod -a -G nagios,nagcmd www-data