Working with Docker images

In the previous chapter, we demonstrated the typical Hello World example using the hello-world image. Now, there is a need for a closer observation of the output of the docker pull subcommand, which is the de facto command to download Docker images. Now, in this section, we will use the busybox image, one of the smallest but a very handy Docker image, to dive deep into Docker image handling:

If you pay close attention to the output of the docker pull subcommand, you will notice the Using default tag: latest text. The Docker image management capability (the local image storage on your Docker host or on a Docker image registry) enables storing multiple variants of the Docker image. In other words, you could use tags to version your images.

By default, Docker always uses the image that is tagged as latest. Each image variant can be directly identified by qualifying it with an appropriate tag. An image can be tag-qualified by adding a colon (:) between the tag and the...