A container image is a binary file that follows a specific standard. The emerged standard for this format is OCI, governed by the Open Container Initiative as part of the Linux Foundation.

When a container runtime engine unpacks these files from the image and starts them on the operating system, the container instance is running. In the end, containers are highly isolated processes that run on an operating system (commonly Linux).

Containers are also the base application building blocks for solution sets that run on Kubernetes. Kubernetes handles the massive effort of real-time coordination of these containers across a farm of server nodes.

How container images are built and how container runtime engines interpret these images is interesting and often important to understand. The best way to start understanding how they function is to build and run your own container image.

In this lab, you will learn how to:

    ☐ Package an application into a container image
    ☐ Start an application container using a container runtime
    ☐ Run your apps securely in containers
    ☐ Use a container image registry

Along the way, you’ll also learn the benefits of multistage Dockerfile, and you’ll explore container images with the Dive tool.