Containerd

What a container actually is on an Ubuntu VM — three problems that VMs and containers each solve, the runtime stack from dockerd and kubelet down to runC, why runC vanishes and containerd-shim stays as the parent, the six namespaces and one cgroup directory seen through /proc.

kubelet 과 컨테이너 런타임 사이의 규격(CRI)과, 그 규격을 구현한 대표 런타임(containerd). 실제 컨테이너는 그 아래 runc 가 만든다.