[FEATURE] Support for containerd/lima as a runtime

[ferhatying]

Is your feature request related to a problem or a Pull Request

A lot of people are using k3d in combination with Docker Desktop for Mac/Windows. Docker Desktop for Mac/Windows is closed source and proprietary. It would be great if we could combine k3d with an open source alternative on the desktop. Support for Docker seems to be hardcoded right now in https://github.com/rancher/k3d/blob/main/pkg/runtimes/runtime.go.

I'm aware that Rancher Desktop does use Lima and k3s/containerd under the hood.

Scope of your request

A new runtime for k3d next to the existing runtime (Docker) at https://github.com/rancher/k3d/blob/main/pkg/runtimes/runtime.go.

Describe the solution you'd like

Add a new runtime under https://github.com/rancher/k3d/blob/main/pkg/runtimes for lima/containerd. Allow users to configure the default runtime (e.g. with a configuration file).

[iwilltry42]

Hi @ferhatying , thanks for opening this issue!
This is definitely something I'd like to add in the future 😄
It just takes quite some effort, as we're relying on the SDKs here. Back then, we had initial support for plain containerd but ran into version conflicts with containerd used by docker...

[sathuish]

@iwilltry42 Any updates on this? Do you have any idea when we will start supporting the containerd runtime in k3d?

[claywd]

Could you get away with using nerdctl to interface with containerd instead of trying to interface directly with the containerd runtime? basically use nerdctl as a drop in replacement for docker.

Update this isn't going to happen. We still need the docker Deamon even if its the replacement provided by rancher desktop.