Repo2docker: document how to choose which registry you want to use

[choldgraf]

[willingc]

@choldgraf Do you want to close this?

[choldgraf]

hmmm - I just looked through the docs and didnt see any mention of this. @yuvipanda is it even possible? If not then we should close this, if so then we should document this and then close this :-)

[yuvipanda]

I'm unsure what the question means? :)

[choldgraf]

r2d will automatically push your image to an image registry...is it possible to configure which registry this goes to? (e.g. gcr.io vs. dockerhub)?

[yuvipanda]

IMO that's outside of our scope, since different registries will have wildly varying authentication mechanisms. We function the same way as 'docker push' - so if your image name is 'gcr.io/' it will push there, assuming you have the authentication for that set up. Perhaps we can mention that specifying the image name (and pushing with --push) works the same way as docker push? So if something works with docker push, it should work with r2d's --push (we use the same API). How to get it to work with docker push is not something we can help with, but if pushing to your registry works with docker push but not --push then we can.

[choldgraf]

perfect - when I get a moment I'll make a PR adding that language

[jzf2101]

Is this still something we need to add?

[choldgraf]

hmm, I'm not sure...perhaps we can do a comb-through of repo2docker issues soon to triage / close / etc. Want to spend a moment doing this with me next week @jzf2101 ?