We use Proget to mirror docker hub for faster builds, but sometimes pull from project just fail due to internal server error.
Our configuration contains the feed, and connector for that feed to docker hub. The feed somehow starts to contain two copies of the same manifest with identical digests, and every attempt to pull this image fail due to "two manifests with same digets" error on proget side.
Also our configuration contains gitlab runner that can run two jobs in parallel, and CI config that contains two jobs with same image (docker:cli). And that image is failed to pull each time new version pushed on docker hub.
I was unable to reproduce this failed state (probably wrong timings), but possible steps are like this:
- configure feed and connector,
- pull some image with floating tag from feed,
- update image at upstream (or wait for image to be updated by maintainers),
- pull that image again by two clients at the same time
Expected result:
New image cached at proget, and pulled by clients
Actual result:
New image cached at proget twice, but cannot be pulled by clients.