It would be nice to be able to search Docker images/manifests by label. Sample use case:
I have a Jenkins server that, every time I make a commit to my project, builds a Docker image, assigns a label to the image named org.label-schema.vcs-ref with value as the Git commit hash, and pushes it into Nexus. When I'm ready to release a new version of my project, I tag a particular commit with the version number. Jenkins then locates the Docker image that was already built for that commit, tags it with the version number, and pushes it into Nexus again.
This use case is easily doable if I can commit to keep all the Docker images on my Jenkins worker node, as I can run docker image ls --filter label=org.label-schema.vcs-ref=HASH and the local Docker daemon will find it for me. If, however, I don't have the images locally, there is currently no good way to search for the image digest that has a particular label, either present or with a specified value. Artifactory has this functionality, though it has other issues. It would be very nice if Nexus provided the ability to query Docker image labels. Note that it would need to be possible to search assets in addition to components, as the search needs to be able to turn up old manifests that aren't currently tagged with anything.