The script listens and exposes events of docker to Zabbix
It sends data to Zabbix via zabbix_sender. You have to configure discovery rule in Zabbix in order to receive data from the script. See Template_Docker_Basic in examples/docker_templates.xml.
The script must be launched as a daemon. You have an example of SysV init-script in examples/init_script.sh.
Execute check_docker --help to find out available parameters which you can define as cli parameters or in config.