Creating a node using source

I have built a all in one from source. got everything working, I have another box with kvm and libvirt etc do I have to install opennebula on that box to make it a node or is just use onehost command after I set up oneadmin user and groups and ssh on said box

You will need to create the oneadmin user the kvm box, configure libvirt and kvm according to:

set-up ssh keys (oneadmin user in frontend should be able to access this kvm box without password), configure network, etc…

and then simply add it to opennebula using onehost.