Docker show current registry

Question

In docker, how can one display the current registry info you are currently logged in? I installed docker, if I now do docker push, where does it send my images?

I spend over 30min searching this info from Google and docker docs, and couldn't find it, so I think it deserves its own question.

Answer 1

There's no concept of a "current" registry - full image tags always contain the registry address, but if no registry is specified then the Docker Hub is used as the default.

So docker push user/app pushes to Docker Hub. If you want to push it to a local registry you need to explicitly tag it with the registry address:

docker tag user/app localhost:5000/user/app docker push localhost:5000/user/app 

If your local registry is secured, you need to run docker login localhost:5000 but that does not change the default registry. If you push or pull images without a registry address in the tag, Docker will always use the Hub.

This issue explains the rationale.