What is the high-level runtime?

• The high level runtime is called containerd
  • It was developed by Docker Inc and at some point donated to CNCF
  • It manages the whole lifecycle of a container - start, stop, remove and pause
  • It take care of setting up network interfaces, volume, pushing and pulling images, ...
  • It manages the lower level runtime (runc) instances
  • It's used both by Docker and Kubernetes as a container runtime
  • It sits between Docker daemon and runc at the OCI layer

Note: running ps -ef | grep -i containerd on a system with Docker installed and running, you should see a process of containerd