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Comment by xpressvideoz | Hacker News Reader

I was amazed by the news at first, but seeing it again, it doesn't seem to be a direct replacement of Docker Desktop. It makes use of K3s under the hood, which is lighter than a full-blown Kubernetes, but still quite heavy. My nearly empty K3s cluster is consistently consuming ~10% CPU time on my local machine. This is not acceptable to me, so a proper replacement of Docker Desktop should be more lightweight.

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Ach, the title seems to be mis-selling it.

Docker Desktop is all about Docker, Compose and Swarm, and has Kubernetes functionality built on top as an extra. Rancher Desktop seems to be all about Kubernetes - can it even run standalone Docker containers, or Compose/Swarm services?

EDIT: answering my own question - I checked the nerdctl GitHub page, and it states that not only is Swarm not supported, but it will not be. So Rancher Desktop is unfortunately not a drop-in Docker Desktop replacement for everyone :(

Swarm is a cluster solution made on top of Compose so it isn't useful on a local machine.

It's very useful on a local machine if you're using Swarm in production, as Swarm supports some additional things that Compose doesn't.

The differences are:

- Replicas: could be made with YAML templating

- Update/rollback policies other than stop-first, very useful on a local machine?

- Resource limits: stayed in v2 to sell Swarm, although there's cgroup_parent which has to be created manually

There are yet more differences.

For example, Swarm supports `configs`, while Compose does not - and I use `configs`, and would much rather not have to have separate service definitions for dev and prod to work around such insufficiencies.

It also comes with nerdctl (docker compatible cli). It interacts with containerd directly and is a drop-in replacement for docker cli.

Oh that's nice, would it be possible to run containerd only, without running any Kubernetes controllers? I suspect the controllers are the root cause of the huge resource consumption, because they are constantly checking for the system components and trying to reconcile them.

Yep! If you’re on MacOS check out Lima, it’s a project by Akihiro Suda who is one of the main contributors to nerdctl (and the original author iirc)

Rancher Desktop macOS version is based on Lima.

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