We have a use case where we need to create an image and push it to multiple repositories To accomplish this now, we create a single image, tag it multiple times, then push to all repositories. For example:

docker build -t repository01.com:2018.08.23 .
docker tag repository01.com:2018.08.23 repository02.com:2018.08.23
docker tag repository01.com:2018.08.23 repository03.com:2018.08.23

docker push repository01.com:2018.08.23
docker push repository02.com:2018.08.23
docker push repository03.com:2018.08.23

Currently gradle-docker can accept multiple tags when creating an image, but this is only applied to the actual docker tag after the colon. I am proposing allowing users to specify multiple names in addition to multiple tags. Each tag would then be applied to each name. When the user runs gradle dockerPush, it cleans / prepares / execs / as usual. During the tag step, the names list is iterated and a tag applied to each name, then during the push step, every : pair is pushed.

This is something I am willing to work on in my spare time if the maintainers think this would be a useful feature.