Change a runbook process to use execution containers

Lianne Crocker discusses the process of transitioning a runbook to use execution containers instead of running steps directly on a worker machine. This change allows for minimal software installation on the worker machine, with software versions being maintained in Docker images used as execution containers. The project, PetClinic Infrastructure, which utilizes Google Cloud Platform, requires updating bootstrapping scripts to install Docker on new GCP virtual machines. Crocker details creating a Docker image that includes the Google SDK and PowerShell, which is published on Docker Hub. The runbook to be converted, "Destroy the GCP Kraken," involves refactoring steps to extract the destruction of the worker machine into a separate runbook, "Destroy Ubuntu worker." This process includes setting up Docker images for different tasks, such as managing DNS records with Azure CLI, and adjusting scripts for authentication and execution within containers. The conversion to execution containers simplifies updates across projects by allowing changes to be managed through Docker image versions, though caution is advised against using the 'latest' image version to maintain control over changes.