Consider using CRI for docker runtime

[afbjorklund]

Just like the "dockershim" in Kubernetes, the cruntime uses direct commands for Docker.

https://github.com/kubernetes/minikube/blob/master/pkg/minikube/cruntime/docker.go

It would be nice if it would use the CRI (where possible), like the other runtimes are doing.

https://github.com/kubernetes/minikube/blob/master/pkg/minikube/cruntime/cri.go

We do have the crictl all configured, so just a matter of "flipping a switch" basically.

The initial approach might be to introduce a feature toggle, to make it opt-in to start with...

[afbjorklund]

Once docker also uses it, we could consider making CRI mandatory like we did with CNI.

Currently it is still in alpha, but it has been a lot in the news lately. (See also #9639)

[afbjorklund]

There is now: https://www.mirantis.com/blog/mirantis-to-take-over-support-of-kubernetes-dockershim-2/

The initial prototype is at https://github.com/dims/cri-dockerd, it should be ready before kubernetes 1.23...

[afbjorklund]

We don't call the CRI functions yet (like populateCRIConfig), so we don't get a crictl.yaml for instance:

image connect using default endpoints: [unix:///var/run/dockershim.sock unix:///run/containerd/containerd.sock unix:///run/crio/crio.sock]. As the default settings are now deprecated, you should set the endpoint instead.

[medyagh]

I belive we merged a PR on this

[afbjorklund]

I belive we merged a PR on this

Just for setting dockershim in /etc/crictl.yaml, though ? (to avoid a warning). Not for starting to use a CRI for docker ?

1278b94

So far I don't think there are any releases of cri-dockerd available, then again the whole CRI is still in Alpha (since 1.5).

But we could start to write the code, and make it opt-in using a boolean. Like we have done with the SSH docker-env ?

[afbjorklund]

Using https://github.com/dims/cri-dockerd until https://github.com/Mirantis/cri-dockerd has more than just a README...

See Mirantis/cri-dockerd#1 and https://www.mirantis.com/blog/mirantis-to-take-over-support-of-kubernetes-dockershim-2/