Vagrant box creation using Packer

packer-vagrant.json

{
	"builders": [{
        "type": "vagrant",
        "source_path": "centos/7",
        "box_name": "test",
        "provider": "virtualbox",
        "communicator": "ssh",
        "ssh_port": 22,
        "ssh_username": "vagrant",
        "skip_add": true
      }]
}