So far, we have seen how to create images, how to store the images in a registry, and how Docker images work in general (layers and containers versus images). An important part of any application is the storage. In general, Docker applications should be stateless, but with the new orchestration software, such as Kubernetes, Docker Swarm, and similar, every day, more and more engineers are moving toward containerized databases. Docker solves this problem in a very elegant way: you can mount a folder from the local machine into the container as if it were a normal folder. This is a very powerful abstraction as it leverages the ability to push data out of the container to be saved into a Network Attached Storage (NAS) or any other storage technology (it is possible to use a bucket in the Google Cloud Storage or S3 as the volume mounted in a container).

Let's start with the basics. Just run a MySQL database:

docker run --name my-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql...