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

(github.com)
726 points psviderski | 2 comments | 18 Jun 25 23:17 UTC | HN request time: 0s | 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

Show context
jlhawn ◴[18 Jun 25 23:52 UTC] No.44314256[source]▶
A quick and dirty version:

    docker -H host1 image save IMAGE | docker -H host2 image load
note: this isn't efficient at all (no compression or layer caching)!
replies(4): >>44314454 #>>44314642 #>>44314686 #>>44314973 #
1. rgrau ◴[19 Jun 25 00:41 UTC] No.44314454[source]▶
I use a variant with ssh and some compression:

    docker save $image | bzip2 | ssh "$host" 'bunzip2 | docker load'
replies(1): >>44314605 #
2. selcuka ◴[19 Jun 25 01:14 UTC] No.44314605[source]▶
If you are happy with bzip2-level compression, you could also use `ssh -C` to enable automatic gzip compression.