https://containerd.io/
https://containerd.io/docs/
https://containerd.io/docs/getting-started/
    containerd config default > /etc/containerd/config.toml

https://github.com/containerd/containerd
https://github.com/containerd/containerd/blob/main/docs/getting-started.md
https://github.com/containerd/containerd/blob/main/docs/ops.md
https://github.com/containerd/containerd/tree/main/docs/cri
https://github.com/containerd/containerd/blob/main/docs/cri/architecture.md
https://github.com/containerd/containerd/blob/main/docs/cri/crictl.md
https://github.com/containerd/containerd/blob/main/docs/cri/registry.md
https://github.com/containerd/containerd/blob/main/docs/cri/testing.md

apt # dpkg -L ...
    containerd.io
        /etc/containerd/config.toml
        /lib/systemd/system/containerd.service
        /usr/bin/containerd-shim-runc-v1
        /usr/bin/containerd-shim-runc-v2
        /usr/bin/ctr
            need a running
            /run/containerd/containerd.sock
        /usr/bin/runc
    containerd

sudo ctr
    plugins ls

$ sudo systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2022-04-06 07:08:55 +03; 3h 52min ago
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
   Main PID: 2308 (dockerd)
      Tasks: 175
     Memory: 177.6M
     CGroup: /system.slice/docker.service
             ├─ 2308 /usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock

2021
https://iximiuz.com/en/posts/containerd-command-line-clients/
    !!!
https://kruyt.org/migrate-docker-containerd-kubernetes/
    https://habr.com/ru/company/southbridge/blog/550702/
    ! about migration from docker
2019
https://habr.com/ru/company/flant/blog/442036/
2017
https://habr.com/ru/company/flant/blog/325358/
????
https://russianblogs.com/article/6159553787/

minikube-integration
https://kubernetes.io/ru/docs/setup/learning-environment/minikube/
    minikube start \
      --network-plugin=cni \
      --enable-default-cni \
      --container-runtime=containerd \
      --bootstrapper=kubeadm
    # or a full-version
    minikube start \
      --network-plugin=cni \
      --enable-default-cni \
      --extra-config=kubelet.container-runtime=remote \
      --extra-config=kubelet.container-runtime-endpoint=unix:///run/containerd/containerd.sock \
      --extra-config=kubelet.image-service-endpoint=unix:///run/containerd/containerd.sock \
      --bootstrapper=kubeadm


/usr/lib/systemd/system/containerd.service
[Unit]
Description=containerd container runtime
Documentation=https://containerd.io
After=network.target local-fs.target

[Service]
ExecStartPre=-/usr/bin/modprobe overlay
ExecStart=/usr/bin/containerd

Delegate=yes
KillMode=process
Restart=always
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNPROC=infinity
LimitCORE=infinity
LimitNOFILE=1048576
# Comment TasksMax if your systemd version does not supports it.
# Only systemd 226 and above support this version.
TasksMax=infinity

[Install]
WantedBy=multi-user.target

????
/var/run/docker/containerd/containerd.toml