Request for Global docker_registry or similar variable

Feature Request

Why

Hi,

We are attempting to use our bigbang customer template for an airgap deployment. Right now I am righting a script to try to replace all uses of ironbank images with a mirror pointing to ironbank. I'd like to request a global "registry" variable used for all docker images, which could then be changed in the customer template to be a custom docker registry

Proposed Solution

I'd like to propose a global "ironbank_mirror" or "docker_registry" variable which can be set in the customer template to e.g. "nexus.internal-org.com". The customer could then use the nexus registry which should mirror images.