I've figured out a bit about storage, both for Docker and for Kubernetes. By default, both systems have some local storage for the life of a container, but when the container stops the storage is cleared too, not ideal if there is something you actually need to store. To work around this and to provide "long term" storage, both systems have a way to use persistent storage. On Docker, it is called persistent volumes, and it allows various containers to share the storage if they so choose. For Kubernetes, you need a storage "driver" which hosts the actual physical storage, and then that is allocated to a pod through a reservation. So far, this is all a bit theoretical; I haven't played with it for real yet, but soon. I did spend some time building a few Docker images -- getting a sample to build first, then a simple PHP application with a web server and finally a tiny Python script to fetch a file. Now none of these were built from scratch, the later two were built by hacking and reading rather than following a tutorial. I also bought some hardware to use for the Pi cluster, at least until I figure out netbooting. Maybe soon though!