In the last section of this chapter, we will cover container storage or Docker volumes as they are referred to. We will take a look at data volumes and data volume containers, the differences between the two, and when to use which one. Lastly, we will also look at the best practices for Docker volumes. This is the data that we want to be persistent or shared between containers. We need to remember that, by default, when you exit a running container, the data isn't saved. When you start the container backup, it will start in its initial state, so Docker volumes become incredibly important in areas like databases or filesystems.
Another switch that we will be covering is the -v or --volume= switch. This switch allows you to provide a volume to the Docker container that you wish contained persistent data. Remember that, when you start a Docker container, the data inside doesn't remain persistent unless you save it (or commit in Docker terms). The volumes switch allows you to have...