Suggestion: option for docker pull over ssh

In case you think this is a good idea, a suggestion would be to also be able to pull over ssh, not just push, so one can pull an image from user@someHost where an image has been built.
More like rsync where both pushing and pulling over ssh is an option.

[yuzhichang]

@ghost Please try my PR #34

[tonyo]

Thanks @yuzhichang for drafting the change 👍

Briefly discussed it with @psviderski. It certainly adds more complexity to an already long bash script, but could still be a nice addition, to make the plugin more feature-complete in an obvious way.

A maybe naive question first though, before we dive into reviews: what actual real-life use cases do you all see for the pull feature?

For pushing from local to remote I see a couple of valid non-abstract use cases, e.g. this one which is pretty tangible: I have an image (as part of my docker-compose file) which needs to be built, and then I want to start it on my VPS (also via docker-compose). I don't want to use any external registry, building the image on the remote server is also meh because the docker-compose context directories are part of a private github repo that I don't want to check out on the remote. docker pussh is a helpful solution here.

Honestly curious to hear about the usage scenarios for pulling the image from the remote server.

[yuzhichang]

@tonyo A pull mode use case: The hub.docker.com is terrible unstable since I'm inside GFW. I have a VPS outside GFW. I need to fetch an image from hub.docker.com on my laptop(inside GFW). So I do docker pull <image> on the VPS, then do docker pussh <vps> <image> (pussh pull mode) on my laptop. Notice that SSH from laptop to VPS is ok, the reverse is NOK since my laptop has no public IPv4 address.