Basics
The building blocks, explained once: image layers, registries, runc and Kubernetes.
Container image layers, explained
An image is a stack of layers, not one file. What a layer is, how they stack at run time, why the build cache works the way it does, and why deleting a secret doesn’t remove it.
Container registries, explained: tags, digests and what a pull really does
A registry stores images as layers and manifests. How image names work, what happens during a pull, why tags can change under you, and how to pin by digest.
What is Kubernetes? A guide for people who already use containers
You can run a container. Kubernetes runs thousands across many machines and keeps them running. The pieces, what a pod is, and where containerd and runc fit in.
What is runc? The small program that actually starts your container
Docker, containerd and Kubernetes all end in the same place: runc. What it does, what it needs as input, and how to run a container with nothing but runc.