Introducing Amazon ECR
In Chapter 1, we talked about the general structure of a container and how it uses a union filesystem to create a layered image. This image format has become the Open Container Initiative (OCI) image specification, and various open source build tools such as Podman or BuildKit support this format.
When you build an image using the docker build command, an image is created locally, which is fine for the local machine, but when you need to use that image in EKS or another Kubernetes distribution/service, you need to push it to a repository that can be accessed by other systems that make up your EKS cluster.
If you browse Docker Hub at https://hub.docker.com/ and log in, you can see multiple container images for Postgres, Redis, Python, and so on. Each image is tagged with a version tag such as 13.8 as well as potentially the latest tag, which will often (but not always) denote the latest version of a container image. Docker Hub is a public repository, which...
