▸ Push docker images directly to remote servers without an external registry ◂

Unregistry is a lightweight container image registry that stores and serves images directly from your Docker daemon's storage.

The included docker pussh command (extra 's' for SSH) lets you push images straight to remote Docker servers over SSH. It transfers only the missing layers, making it fast and efficient.

You've built a Docker image locally. Now you need it on your server. Your options suck:

• Docker Hub / GitHub Container Registry - Your code is now public, or you're paying for private repos
• Self-hosted registry - Another service to maintain, secure, and pay for storage
• Save/Load - docker save | ssh | docker load transfers the entire image, even if 90% already exists on the server
• Rebuild remotely - Wastes time and server resources. Plus now you're debugging why the build fails in production

You just want to move an image from A to B. Why is this so hard?

docker pussh myapp:latest user@server

That's it. Your image is on the remote server. No registry setup, no subscription, no intermediate storage, no exposed ports. Just a direct transfer of the missing layers over SSH.

Here's what happens under the hood:

1. Establishes SSH tunnel to the remote server
2. Starts a temporary unregistry container
3. Forwards a random localhost port to the unregistry port over the tunnel
4. docker push to unregistry through the forwarded port, transferring only the layers that don't already exist remotely. The transferred image is instantly available on the remote Docker daemon
5. Stops the unregistry container and closes the SSH tunnel

It's like rsync for Docker images — simple and efficient.

brew install psviderski/tap/docker-pussh

After installation, to use docker-pussh as a Docker CLI plugin (docker pussh command) you need to create a symlink:

mkdir -p ~/.docker/cli-plugins
ln -sf $(brew --prefix)/bin/docker-pussh ~/.docker/cli-plugins/docker-pussh

# Download the latest version
curl -sSL https://raw.githubusercontent.com/psviderski/unregistry/main/docker-pussh \ -o ~/.docker/cli-plugins/docker-pussh # Make it executable
chmod +x ~/.docker/cli-plugins/docker-pussh

Windows is not currently supported, but you can try using WSL 2 with the above Linux instructions.

Push an image to a remote server. Please make sure the SSH user has permissions to run docker commands (user is root or non-root user is in docker group). If sudo is required, ensure the user can run sudo docker without a password prompt.

docker pussh myapp:latest user@server.example.com

With SSH key authentication if the private key is not added to your SSH agent:

docker pussh myapp:latest ubuntu@192.168.1.100 -i ~/.ssh/id_rsa

Using a custom SSH port:

docker pussh myapp:latest user@server:2222

Push a specific platform for a multi-platform image. The local Docker has to use containerd image store to support multi-platform images.

docker pussh myapp:latest user@server --platform linux/amd64

Build locally and push directly to your production servers. No middleman.

docker build --platform linux/amd64 -t myapp:1.2.3 .
docker pussh myapp:1.2.3 deploy@prod-server
ssh deploy@prod-server docker run -d myapp:1.2.3

Skip the registry complexity in your pipelines. Build and push directly to deployment targets.

- name: Build and deploy run: |
 docker build -t myapp:${{ github.sha }} .
 docker pussh myapp:${{ github.sha }} deploy@staging-server

Distribute images in isolated networks without exposing them to the internet.

docker pussh image:latest user@192.168.1.100

• Docker CLI with plugin support (Docker 19.03+)
• OpenSSH client

• Docker is installed and running
• SSH user has permissions to run docker commands (user is root or non-root user is in docker group)
• If sudo is required, ensure the user can run sudo docker without a password prompt

{ "features": { "containerd-snapshotter": true
  }
}

Sometimes you want a local registry without the overhead. Unregistry works great for this:

# Run unregistry locally and expose it on port 5000
docker run -d -p 5000:5000 --name unregistry \ -v /run/containerd/containerd.sock:/run/containerd/containerd.sock \ ghcr.io/psviderski/unregistry # Use it like any registry
docker tag myapp:latest localhost:5000/myapp:latest
docker push localhost:5000/myapp:latest

Need custom SSH settings? Use the standard SSH config file:

# ~/.ssh/config
Host prod-server HostName server.example.com User deploy Port 2222 IdentityFile ~/.ssh/deploy_key # Now just use
docker pussh myapp:latest prod-server

Found a bug or have a feature idea? We'd love your help!

• Spegel - P2P container image registry that inspired me to implement a registry that uses containerd image store as a backend.
• Docker Distribution - the bulletproof Docker registry implementation that unregistry uses as a base.