I was wondering how to use non-official docker images with zun. Those docker images that do not have a username attached to them, like alpine for example, I do not have trouble using, but something like tleemcjr/metasploitable2 seems unable to be found.

Is there a special trick to getting these images to work? Do I need to download the image beforehand?

Just as a note, I've been using horizon to deploy these containers and have not tried the command line.