How to replicate:
1. Create a new docker repository (I used the default url: https://registry-1.docker.io/ and busybox as upstream repository name.)
2. Sync the new repository.
3. Create a new content view and assign it the docker repository.
4. Publish the content view, it should give the error: Validation failed: Repository URL or Upstream Name is empty. Both are required for syncing from the upstream.
Created from redmine issue http://projects.theforeman.org/issues/14305
Upstream bug component is Content Views
Upstream Katello PR: https://github.com/Katello/katello/pull/5908
Used manual reproducer in comment#0:
Successfully published Docker View version 1.0 and promoted to Library
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.