VM-Series qcow2 image:

The qcow2 image format is commonly used in OpenStack environments. The VM-Series firewalls are provided in the qcow2 format for compatibility with OpenStack.

Palo Alto Networks VM-Series Deployment Guide

OpenStack heat template in YAML format:

OpenStack Heat Orchestration Templates (HOT) are written in YAML. These templates define the infrastructure needed for deployment and can automate the deployment process.

OpenStack Heat Documentation