Chapter Summary

In this chapter, we learned about Docker images. We learned that they contain everything needed to run an application. This includes: just enough OS, source code files, and dependencies. In some ways, images are like virtual machine templates and are used to start containers. Under the hood, they are composed of one or more read-only layers that when stacked together, make up the overall image.

We used the docker image pull command to pull some images into our Docker host’s local registry.

We covered image naming, official and unofficial repos, layering, sharing, and crypto IDs.

We looked at how Docker supports multi-architecture and multi-platform images, and we concluded this chapter by looking at some of the most common commands used to work with images.

In the next chapter, we’ll take a similar tour of containers—the runtime sibling of images.