More coming soon, check the Icinga2 docs or the Monitoring-Portal for info.

docs.icinga.org - setting up the user interface
Monitoring Portal

apt-get install icingaweb2

Browse to your-server.local/icingaweb2/setup

Create a token via commandline and enter it in the setup

icingacli setup token create

Create a database for user configuration

mysql -uroot -p
[mysql]> CREATE DATABASE icingaweb2;
[mysql]> GRANT ALL ON icingaweb2.* TO icingaweb2@localhost IDENTIFIED BY 'CHANGEME/PASSWORD';

Follow the instructions on the setup