"# Docker vs Containerd

Kubernetes requires a container runtime (CRI) as part of the Open Container Initiative (OCI) standards.

Most Popular Container Runtimes

1. Docker
2. rkt.io
3. Containerd

Kubernetes and Docker Support

• Kubernetes originally supported Docker via dockershim.
• Starting from Kubernetes 1.24, Docker support has been removed.
• Containerd is now fully compatible with CRI and recommended for Kubernetes.

Containerd CLI Tools

• ctr: A CLI tool that comes with containerd.

  • It supports limited features compared to Docker.
  • Example usage:

    ctr images pull <image-name>

• nerdctl: A tool similar to Docker CLI.

  • Supports Docker Compose and provides a Docker-like CLI.
  • Most Docker commands work seamlessly with nerdctl.

• crictl:

  • Used to inspect and debug container runtimes.
  • Especially useful for Kubernetes environments relying on CRI-compatible runtimes. """