matchbox/examples/groups/etcd3-install/install.json

{
  "id": "coreos-install",
  "name": "CoreOS Container Linux Install",
  "profile": "install-reboot",
  "metadata": {
    "coreos_channel": "stable",
    "coreos_version": "1520.8.0",
    "ignition_endpoint": "http://matchbox.example.com:8080/ignition",
    "baseurl": "http://matchbox.example.com:8080/assets/coreos"
  }
}