Pushing hangs when no upstream connection

[mottetm]

Hi everyone,

We have a registry set up with on-demand sync to our main upstream registry, this works very well for us when we are able to access the upstream registry but our issues start when we loose that connectivity. We need to support delivery of images to these offline registries and would have like to do this without disabling the on-demand sync. However, during the push process, the initial HEAD request hangs when the registry tries to sync with the upstream manifest which is not available, or sometimes, it resolves within a reasonable amout of time, it's a bit random. We were hoping that the request would timeout predictably and that the local data would be used, if available, but that doesn't seem to happen consistently. Is that the expected behavior? There doesn't seem to be any timeout set on the image sync, adding one could be a good solution to the issue. I'm happy to contribute some PR but would love to hear your opinion first.

Best,
Matthieu

[andaaron]

Hi @mottetm, I submitted #3522 to track this.