UbuntuDebianSLESRHEL

usermod -a -G icingaweb2 www-data
systemctl restart apache2

usermod -a -G icingaweb2 www-data
systemctl restart apache2

usermod -a -G icingaweb2 wwwrun
systemctl restart apache2

usermod -a -G icingaweb2 apache
systemctl restart httpd