This is based on a Check_MK plugin downloaded from the Github Repo below.
Firstly, clone the repository from Github and browse to the directory (On your Check_MK Server):
git clone https://github.com/michalskalski/cmk-apcupsd.git cd cmk-apcupsd
Now install the plugin:
check_mk -P install cmk-apcupsd-1.0.mkp
Now download the plugin from the Check_MK agents page from your Monitoring server (See here for setting up an Agent Downloads Page if you have not already done this):
cd /usr/lib/check_mk_agent/plugins/ wget http://[Monitoring-Server]/agents/plugins/apcupsd chmod +x apcupsd
Re-inventory the server
cmk -II [server-name]
Reload Check_MK to pull the latest plugins