Packer is a tool for building virtual machines. Our team has used this to provide both vagrant images for local testing and cloud images for our production virtual machines.
Here's a quick run down of what it works.
First you‘ll need to download packer. Once you’ve got that you'll need a solution for virtualizing to build the VM. On Debian I installed qemu-kvm and needed to add my user to the kvm group. Once that was done it was just a matter of making tweaks: adding packages, changing the resources to fit your local system, or playing with ponies. PACKER_LOG=1 /where/is/packer build ubuntu-16.04.json will start blazing. Currenly the VM uses 3gb RAM, 3 vCPU a 10GB disk to build and headless qemu as pono was the last person to commit.
This particular .json is currently being debugged :)