I've configure the docker template on 5.0.1

https://www.zabbix.com/integrations/docker

Starting the agent I receive on my zabbix agent log file : dial unix /var/run/docker.sock: connect: permission denied

 I had to add  the zabbix agent user to the docker group as explained here

https://docs.docker.com/engine/install/linux-postinstall/

I think that can be a common problem

maybe it could be specified in the documentation