[coffeekid]

Not an expert at all, but here's how I would simplify it. All corrections are welcome!

Docker has two main components. The daemon (you can think of it somewhat like a server) and the client (application you use to run commands).

When you install docker on your machine, it generally installs both. The daemon is a process that runs on your local machine and runs as root.

Rootless refers to the alternative method (used by podman for instance) to run the daemon as a standard user, and delegate root-level tasks to something else, like systemd for instance.

[chrisjc]

> Docker has two main components. The daemon (you can think of it somewhat like a server) and the client (application you use to run commands).

Is the daemon what they call the docker-engine? Is this what's available on Linux natively? Rootless makes sense here bc you wouldn't want one docker image able to interfere with another, or even the Linux system that is running the docker runtime/engine.

For Windows/Mac docker solutions, where does the daemon live/exist/run? Inside a virtualized Linux instance?

As I understand it, most of these alternatives to docker-desktop are all just wrappers around a virtualized Linux image running the docker engine/runtime. That's why many of them require a virtualization engine like Virtual Box. So are these no-commercial solutions just wrappers around one or more virtualized Linux runtimes where the docker engine/runtime is running natively?

If all the above is (approx) correct, then "what" is rootless with this announcement? The docker runtime/engine in the virtualized Linux instance?

I thought the docker engine/runtime on Linux was always able to run rootless docker images. So what is the news here if all these non-commercial solutions are just wrappers around the docker engine/runtime running in a virtualized Linux?

[stonemetal12]

Yes for windows and Mac it runs a Linux VM. On windows it can also use WSL2 as the linux vm.

Docker-engine is the daemon built by docker. Podman is an opensource work a like. Docker-engine doesn't support running as a user other than root. Podman does. This announcement says minikube will work with Podman running as not root.

[chrisjc]

Thanks for clearing that up.

I remember hearing that development of docker-engine was ceasing, but could obviously live on as it was forked. I guess rootless is some of the work that Docker (company) wanted to keep proprietary and out of this open-source project.

Really quite a shame, although understandable from a commercial perspective.

Assuming that these improvements are finding their way back into an open-source project, I'm glad to hear about this work from minikube and Podman.

[AkihiroSuda]

> I guess rootless is some of the work that Docker (company) wanted to keep proprietary and out of this open-source project.

Rootless mode for Docker is completely FLOSS, and its main contributor (me) has even never worked for Docker (company).

https://github.com/moby/moby/blob/master/contrib/dockerd-roo...

https://github.com/rootless-containers

[AkihiroSuda]

> Docker-engine doesn't support running as a user other than root. Podman does.

Docker engine does.