Pull-through caches are still useful even when the upstream is down... assuming the image(s) were pulled recently. The HEAD to upstream will obviously fail [when checking currency], but the software is happy to serve what it has already pulled.
Depends on the implementation, of course: I'm speaking to 'distribution/distribution', the reference. Harbor or whatever else may behave differently, I have no idea.
Depends on the implementation, of course: I'm speaking to 'distribution/distribution', the reference. Harbor or whatever else may behave differently, I have no idea.