#31

moby-engine works alongside fedora-toolbox, podman and buildah just fine.

#32

Interesting! Looks like a good solution, however even after some Googling I still don’t fully understand the demarcation between Moby and Docker. What’s in Docker CE that is not provided by the Moby engine?

#33

Docker in Docker, for the curious: https://hub.docker.com/_/docker

And Docker in Podman (see ~jpetazzo/Using Docker-in-Docker for your CI or testing environment? Think twice.:

$ sudo podman run -it --rm --privileged --volume /var/run/docker.sock:/var/run/docker.sock $ sudo podman run -it --rm --privileged --volume /var/run/docker.sock:/var/run/docker.sock docker
/ # docker ps -a
CONTAINER ID        IMAGE                   COMMAND                  CREATED             STATUS              PORTS                                     NAMES
b4633148c948        dpage/pgadmin4:latest   "/entrypoint.sh"         17 minutes ago      Up 17 minutes       80/tcp, 443/tcp, 0.0.0.0:8686->8686/tcp   pgadmin4
d92b53508cc1        rstatsp:latest          "/bin/sh -c 'service…"   17 minutes ago      Up 17 minutes       80/tcp, 443/tcp, 0.0.0.0:8004->8004/tcp   rstats
d966280c0ace        postgis:latest          "docker-entrypoint.s…"   17 minutes ago      Up 17 minutes       0.0.0.0:5432->5432/tcp                    postgis

The containers were started via moby-engine Docker on the Silverblue host. This stuff is probably insecure as all-get-out but it does give me the ability to start a container from inside a container, which is what I want to do for a certain use case.

#34

FWIW it’s a bit different, but depending on your use case you maybe use systemd-nspawn / systemd-machined containers, which are more like a full system with isolated networking + a separate systemd instance running inside.

#35

The use case is I have RStudio Server running in a container and I want to be able to run Docker inside that container. I have it working except for some network routing things I need to configure somehow.

#36

The way I understand it, Moby is the open source project from which Docker is built from. So you are able to pull the Moby code, compile it yourself, and run it. Whereas, Docker CE is a packaged version of the Moby code that you can install on your hosts.

I found the image in this post, showing how the code goes from Moby -> Docker CE -> Docker EE to be helpful in understanding:

https://collabnix.com/demystifying-the-relationship-between-moby-docker/

Additionally, the pull quote from Solomon Hykes mentioned there gave some context:

“Docker [the company] uses the Moby Project as an open R&D lab”

#37

Ah so running Moby in stead of Docker CE is fine for development workloads and would get us a more up-to-date “docker” engine than using the regular docker package in the F29 RPM repository. It’s Docker CE, just not branded that way. At least, I can’t figure out what Docker is adding to Moby that makes Docker CE more that what Moby is.

For now this is a very acceptable workaround, but it would still be desirable to be able to install Podman and Docker CE together on the same machine without version conflicts on shared libraries!

#38

I’m not a lawyer, but I believe there are legal reasons why Fedora is unable to package and distribute Docker CE themselves. So moby-engine is the closest thing that will be offered.

#39

Not sure that’s true given that docker is currently in the F29 RPM repo, all be it an older version. Anyway that’s not the main issue here. I meant it would be nice if there is a way for Podman and Docker CE can be installed simultaneously. That they can coexist on the same Silverblue computer. Also when Docker CE is provided through Docker’s own RPM repo. I know that’s a big ask given that Fedora is not responsible for Docker’s packaging for their own repo, but I’m hoping Fedora could package the its libraries that overlap (like RunC) in such a way that they won’t conflict anymore.

#40

Again not a lawyer, but I seem to recall that some of the agreements about repackaging Docker changed after the introduction of Moby. The version of Docker (1.13) that is provided by Fedora was the last version that was available before the change to Moby.

Anyways, I’m not sure the best path for a co-existence between Docker CE + podman. Since the big difference seems to be with runc, the two projects would somehow have to agree to use the same version. Or radically change how one or the other is packaged.

You could try filing an issue on the upstream podman repo, but I wouldn’t be too optimistic about them trying to co-exist with Docker CE.

#41

I think technically the problem isn’t really podman, since the runc versions are technically compatible. It’s more that podman and therefore runc is in the Silverblue base image. And since packages in the base image can’t be overridden, everything falls apart.

Now that I think about it, you could probably use rpm-ostree override replace with the runc rpm from the Docker repo, then installing Docker normally should probably work.

1 Like
#42

That’s an unacceptably convoluted and risky workaround. You shouldn’t have to interfere with the dependency tree to get the tooling you want. My recommendation is to drop the docker RPM and go with moby-engine.

#43

I’m not necessarily advocating for one way or another, just pointing it out for anyone who may stumble upon this in the future.

#44

I agree, I can’t go without docker at work and I’ve had some weird behavior from the moby-engine versions. Docker CE works perfectly after removing podman, buildah, runc and toolbox first. It works but it’s a bit annoying that you lose podman.

#45
  1. What is the correct way to install moby-engine? I need to add a repository first?
  2. Will it work with Fedora 30?
#46
  1. install it normally (rpm-ostree), no other repos are necessary.
  2. Yes.
1 Like
#47

Thank you very much!!
It’s working now :slight_smile: !

Am I correct and it’s not possible to search packages with rpm-ostree? It can only be done using Fedora toolbox and dnf?

Best wishes!

#48

It is true, rpm-ostree doesn’t offer a search interface, and so using toolbox which have dnf is a good workaround, there is also the website for fedora packages which I use.

1 Like
#49

Thanks for the clarification :slight_smile: !

#50

And what about Docker in Toolbox?