using the git plugin to clone a existing repository?

Im wanting to setup a imageboard which recommends you use git to clone it and pull occasionally,

I have set git up in virtualmin but it appears its just for hosting git repositories not for cloning and pulling them.

Is this doable in virtualmin or do I need to use the command line on SSH for this? or setup a cron or something to keep it auto updated.

I am also trying something similar, if anyone has any ideas.