Credentials for Docker Hub may be stored in different registry entry.

Some people are experiencing an authorization error when pushing to Docker Hub even if pushing with docker works. This may be because Docker Hub credentials could be stored under a different registry entry instead of registry.hub.docker.com. For example, a Docker config (located usually at $HOME/.docker/config.json) could have:

{
	"auths": {
		"https://index.docker.io/v1/": {},
...

We should support this alias as well when using Docker config to fetch credentials.

[chanseokoh]

How should it work exactly? For example, my intuition is that, if the given registry is index.docker.io, it wouldn’t match the entry index.docker.io/v1/ in the Docker config because it is more specific. Conversely, if the given repository is index.docker.io/v1/, it would match entries of both index.docker.io and index.docker.io/v1/. Is that right? And is the suffix only possible in the Docker config or it is generally applicable in other stores like settings.xml and the build configurations (pom.xml and build.gradle)?

[coollog]

I think we can leave that off to a later version, since the users explicitly type the names in settings.xml. (For auth, it is directly tied to the image so there is no alias necessary).