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Show HN: Unregistry – “docker push” directly to servers without a registry

(github.com)
726 points psviderski | 1 comments | 18 Jun 25 23:17 UTC | HN request time: 0.306s | source

I got tired of the push-to-registry/pull-from-registry dance every time I needed to deploy a Docker image.

In certain cases, using a full-fledged external (or even local) registry is annoying overhead. And if you think about it, there's already a form of registry present on any of your Docker-enabled hosts — the Docker's own image storage.

So I built Unregistry [1] that exposes Docker's (containerd) image storage through a standard registry API. It adds a `docker pussh` command that pushes images directly to remote Docker daemons over SSH. It transfers only the missing layers, making it fast and efficient.

  docker pussh myapp:latest user@server
Under the hood, it starts a temporary unregistry container on the remote host, pushes to it through an SSH tunnel, and cleans up when done.

I've built it as a byproduct while working on Uncloud [2], a tool for deploying containers across a network of Docker hosts, and figured it'd be useful as a standalone project.

Would love to hear your thoughts and use cases!

[1]: https://github.com/psviderski/unregistry

[2]: https://github.com/psviderski/uncloud

1. sebastos ◴[27 Jun 25 15:31 UTC] No.44397579[source]▶
Amazing. Our company has to push gigantic docker images to IoT style devices, and we’ve had to maintain an installer script that downloads and stands up a local dummy registry, pushes the image to that, then ssh’s to the remote and pulls from it. When the installer fails, this process is almost always the culprit. Your tool looks like it would be a huge improvement (- although the requirement that the host have the unregistry container is a _slight_ demerit). Nevertheless, I can’t wait to check this out.

I have spent an absolutely bewildering 7 years trying to understand why this huge gap in the docker ecosystem tooling exists. Even if I never use your tool, it’s such a relief to find someone else who sees the problem in clear terms. Even in this very thread you have people who cannot imagine “why you don’t just docker save | docker load”.

It’s also cathartic to see Solomon regretting how fucky the arbitrary distinction between registries and local engines is. I wish it had been easier to see that point discussed out in the open some time in the past 8 years.

It always felt to me as though the shape of the entire docker ecosystem was frozen incredibly fast. I was aware of docker becoming popular in 2017ish. By the time I actually stated to dive in, in 2018 or so, it felt like its design was already beyond question. If you were confused about holes in the story, you had to sift through cargo cult people incapable of conceiving that docker could work any differently than it already did. This created a pervasive gaslighty experience: Maybe I was just Holding It Wrong? Why is everyone else so unperturbed by these holes, I wondered. But it turns out, no, damnit - I was right!