The _Host Provisioner_ is a tool that runs an Anisble playbook to
initially provision a new machine. It is intended to run as a
Kubernetes Job, created by a webhook that is triggered when the machine
boots up for the first time. The tool retrieves information about the
new machine (its hostname and SSH host keys) from a message queue,
published by the same webhook that launched the job. It then clones
the configuration policy (optionally from the branch provided in the
host info message) and applies the `site.yml` playbook.
Dustin