Learning Docker

Working with Docker images

In the previous chapter, we demonstrated the typical Hello World! example by using a busybox image. Now there is a need for a close observation of the output of the docker pull subcommand, which is a standard command for downloading the Docker images. You would have noticed the presence of the busybox:latest text in the output text, and we will explain this mystery in a detailed manner by bringing in a small twist to the docker pull subcommand by adding the -a option, as shown here:

$ sudo docker pull -a busybox

Surprisingly, you will observe that the Docker engine downloads a few more images with the -a option. You can easily check the images that are available on the Docker host by running the docker images subcommand, ...