For my blog post, 'Create Multi-VM Environment Using Vagrant and JSON' (http://wp.me/p1RD28-14c). JSON-based chef configuration file used by Vagrant to build (3) VMs. Project git repository located at: https://github.com/garystafford/multi-oracle-dev-vms.

chef.json

{
  "chef": {
    ":chef_server_url": "https://api.opscode.com/organizations/my-organization",
    ":client_key_path": "/etc/chef/my-client.pem",
    ":environment": "my-environment",
    ":provisioning_path": "/etc/chef",
    ":validation_client_name": "my-client",
    ":validation_key_path": "~/.chef/my-client.pem"
  }
}