docker-over-ssh

docker-over-ssh

Push docker containers efficiently over abitrary streams, e.g. ssh

Installation

On both your local machine, and the remote machine you want to transfer an image to:

npm i -g docker-over-ssh

Usage

To transfer an image called node:12-alpine to a server called dokku over ssh, run:

docker-over-ssh push node:12-alpine ssh dokku "docker-over-ssh pull node:12-alpine"

If you already have a local registry running, that you would like to use, you can specify the LOCAL_DOCKER_REGISTRY_PORT environment variable.

How it works

The local CLI sets up a temporary docker registry (itself made using docker). It then pushes the requested image (and only the requested image) to that docker registry. It then spawns a child process, using the remaining params. In this example, that's ssh dokku "docker-over-ssh pull node:12-alpine". It proxies connections over stdio <-> TCP between that child process and the temporary docker registry.

The remote CLI sets up a TCP server that proxies requests through to stdio (i.e. through to the local CLI's docker registry). It then runs docker pull, which pulls any missing layers over the ssh connection.

This is useful, because it can take advantage of the docker layer caching for much smaller transfers.