CraftConf 2019: CRI Runtimes Deep Dive

Abstract

A significant amount of today’s activity in the world of container orchestration is happening in the Kubernetes community. A little known fact to some users and practitioners on the platform is that Kubernetes itself has no code in the project that can create or start a Linux or Windows container.

So, what code is running the containers within your Kubernetes pods? As it turns out, since Kubernetes 1.5 a new API definition, called the Container Runtime Interface (CRI), allows any CRI-implementing container runtime to plug into the kubelet configuration and provide container runtime services for Kubernetes.

In this talk we’ll deep dive on CRI implementations, and give a hands-on demonstration of how Kubernetes, the CRI, and CRI-supporting runtimes work together to handle the container lifecycle within your K8s pods. More than just talk, we’ll go to the command prompt, digging into the useful capabilities of the CRI and how we can understand the inner workings between Kubernetes and the CRI container runtimes that support it, using containerd, one of the popular runtimes available for use in Kubernetes today.