As discussed in Chapter 4, Deployment Methodologies, whether you are using a traditional virtualization platform such as oVirt or VMware or a cloud-based one such as OpenStack or Amazon's EC2, your starting point for any Linux deployments (and hence further automation) will be a templated image.
In terms of the SOE we defined in Chapter 1, Building a Standard Operating Environment on Linux, the templated image is the very real initial manifestation of this. It is usually a small virtual machine image, with just enough software installed and configuration completed that it is useful in almost all scenarios it might be deployed in for the enterprise. As long as the image boots up cleanly with a unique hostname, SSH host keys, and such, then it can be customized almost immediately using further automation as we shall discover from Chapter 7, Configuration...
