Kubernetes is taking over the world of infrastructure management, at least for larger-scale operations, and best practices have started to solidify. One of those best practices is the cultivation of Custom Resource Definitions (CRDs) to describe your applications in a Kubernetes-native way, and Operators to manage your the Custom Resources running on your Kubernetes clusters.
In the Drupal community, Kubernetes uptake has been somewhat slow, but is on the rise. Just like with Docker adoption for local development, the tooling and documentation has been slowly percolating. For example, Tess Flynn from TEN7 has been
boldly going where no one has gone before (oops, wrong scifi series!) using the Force to promote Drupal usage in a Kubernetes environment.