Support any registry as upstream registry #849
Description
What is the problem you're trying to solve
This is related to ACR cache and active caching feature. Currently only a limited set of upstream registries are supported. Mainly those are public registries that host images. There is no option to configure privately hosted registry like Artifactory, Nexus or Harbor as upstream.
Describe the solution you'd like
We need to be able to support any domain as upstream registry including privately hosted registries.
Additional context
Add any other context or screenshots about the feature request here.