I’ve been using Docker for a couple of years now, but only for running local development environments. That on its own is a great way to use it. With a simple "docker run" or "docker-compose up" you can have a project running locally without installing any prerequisites on your machine. It’s amazing how quickly technology advances. A few years ago, I wouldn’t have believed that you you could run a WordPress site locally without installing nginx, php and mariadb (or Xampp).
When I started playing with Kubernetes a few months ago, there was one question that didn’t seem to have a clear answer: Where do I store the images that will be running in Kubernetes?
Most of the documentation and examples are for deploying ready-made services like nginx or MariaDB. The services tend to be open source with images publicly available on Docker Hub. But sooner or later you’re going to want to build a custom image and deploy it.