Previously, we focused on how to make your application's code deployable on the target infrastructure. The CI system created software packages (such as containers) and those packages were then deployed by the CD process. Each time the pipeline ran, the infrastructure stayed the same, but the software differed.
The point is, if you are using cloud computing, you can treat infrastructure just like any other artifact. Instead of deploying a container, you can deploy an entire Virtual Machine (VM), for example, as an AWS EC2 instance. You can build such a VM image upfront as yet another element of your CI process. This way, versioned VM images, as well as the code required to deploy them, become your artifacts, and not the containers themselves.
There are two tools, both authored by HashiCorp, that deal with precisely this scenario. Packer helps to create VM images in a repeatable way, storing all the instructions as code, usually in the form of...