Checkmk special agent for checking unifi controller
Login into your checkmk instnace user on your checkmk server (e.g. via SSH). Download and install the checkmk agent:
wget https://github.com/bashclub/check-unifi-controller/releases/download/v0.87/unifi_controller-0.87.mkp
mkp install ./unifi_controller-0.87.mkp
Login into your checkmk website and go to "Setup" -> "Agents" -> "Other integrations" (Datasource programs). Under the category "Hardware" click on "Unifi Controller via API" and create a new rule. Fill in the credentials of your Unifi controller, set the HTTPS Port, define the site name (if other than default), check "Ignore certificate validation" if using a self signed certificate, select Hostname or IP for storing piggyback data. Under "Conditions" assign an "Explicit host" with your Unifi Controller Machine. The agent will carry piggyback data for switches and access points and you can create new hosts to monitor, where piggyback data will be assignesd on exact match (IP or hostname).