Prevent pushing no-repository images to dockerhub?

[CB-andrewehrlich]

I am tagging my images with myrepo/image:tag as well as just image:tag. I need the image:tag format for running locally in dev env. But, sbt docker:publish tries to push the image:tag images up to dockerhub, when I would rather that it didn't try to publish them anywhere. Is there any way to get that behavior?

[muuki88]

Hi @CB-andrewehrlich

Thanks for your question. You need to use the docker:publishLocal task to push to your local registry 😃

[CB-andrewehrlich]

The problem is that I need to use docker:publish to push to my private repo. But when I run that task, the tagged image does go to my private repo, but the no-tag image (image:tag) attempts to go to dockerhub, when it ought to do nothing.

[nigredo-tori]

I'm using Docker terminology (registry, tag) here instead of the DockerPlugin one (repository, alias) for clarity.

@CB-andrewehrlich, Docker tags are the coordinates for where your images will be pushed. So if you have foo:123/bar/baz:qux as your Docker/dockerAlias (foo:123 is your registry), then Docker/publishLocal will build a local image foo:123/bar/baz:qux. Docker/publish just pushes the built images to their respective registries. If in the tag doesn't specify the registry, it is assumed (by the Docker itself) to be the default global Docker registry. That is, bar/baz:qux is assumed to be a local version (pulled, or pending push) of docker.io/bar/baz:qux.

So when you are saying that you want publishLocal to build baz:qux, but for publish not to push it, you are straying from the general Docker conventions. I fail to see why this is necessary, and why the DockerPlugin should support this functionality by default. If you have published a foo:123/bar/baz:qux, then it should already be accessible locally under the same tag - why do you need to add another tag, with some non-obvious behavior?

[CB-andrewehrlich]

Yea, that's eventually the conclusion I came to, that Docker assumes no-repo is a synonym for Dockerhub, and there is no real way around that.