You can already achieve the same thing by making your image into an archive, pushing it to your server, and then running it from the archive on your server.

Saving as archive looks like this: `docker save -o may-app.tar my-app:latest`

And loading it looks like this: `docker load -i /path/to/my-app.tar`

Using a tool like ansible, you can achieve easily what "Unregistry" is doing automatically. According to the github repo, save/load has the drawback of tranfering the whole image over the network, which could be an issue that's true. And managing the images instead of archive files seems more convenient.

If you have an image with 100MB worth of bottom layers, and only change the tiny top layer, the unregistry will only send the top layer, while save / load would send the whole 100MB+.

Hence the value.

If you read the README, you'll see that replacing the "save | upload | load" workflow is the whole point of this, to drastically reduce the amount of data to upload by only sending new layers instead of everything, and you can use this inside your ansible setup to speed it up.

Good advice and beware the difference between docker export (which will fail if you lack enough storage, since it saves volumes) and docker save. Running the wrong command might knock out your only running docker server into an unrecoverable state...