You could use something like Terraform to help automate this. It's like CloudFormation but also supports GCE, Azure, DigitalOcean, etc.

0 - https://terraform.io/

Ansible is probably the best bet - once you have SSH it'll pretty much work with anything and it also has support for creation of servers on several cloud providers and stuff.

We use it for automatic configuration of everything from colocated hardware to $5/mo VMs on DigitalOcean and other low-cost virtual server providers and it works great.

Openstack might allow you to do this.

(I haven't used it myself.)