Get/Set private/public ip in Vagrantfile like virtualbox or aws

[juju4]

Hello,

I'm a beginner with digital ocean and try to interact it with Vagrant. it's working ok for simple Vagrantfile but now, I'm trying to port a multi-box configuration.
Basically, the setting is a monitoring server and 2 clients nodes.

My problem: from a Vagrant unique file, how can I get (or set) IP of the server to push it inside client nodes.
Ideally, there would be cases, when I will need to push client IPs to the server, so if it can be retrieved, better.
With a local provider, I can set private network ip, same for aws. I don't see any option with digital ocean. don't believe any of them can do public ip.
Ex:
http://nitschinger.at/A-Couchbase-Cluster-in-Minutes-with-Vagrant-and-Puppet
http://spin.atomicobject.com/2014/02/14/constructing-vagrant-cluster-chef-development/

is it a coding issue? or an API one?

Thanks