An overview of the Kubernetes Container Runtime Interface (CRI)

What this post added

This post introduces the Kubernetes Container Runtime Interface (CRI) as a solution to decouple kubelet from specific container runtime implementations, particularly Docker. It explains the motivation behind CRI, which arose from the need to support multiple runtimes and manage the evolving Docker interface. The post details CRI's role in standardizing container runtime interactions, its compliance requirements with OCI specifications (including runc), and the validation tests necessary for integration. It also provides an architectural overview of containerd as a CRI implementation and mentions other integrations like cri-o and dockershim.