simple cli to get all images required in offline

[spyroot]

HI Folks,

If you need to push images to an air-gapped server, gathering all the required images during an e2e run is very difficult.
Without a Kubernetes cluster, getting a complete list of the images required for e2e tests is nearly impossible.

For example, when running tests via the CLI, if a specific conformance test is already configured to pull images, why not provide a complete list of images and their full repository paths upfront? This would save significant time and effort.

As an example, I encountered a test that tried to pull e2e-test-images/sample-apiserver:1.29.2. After checking four different registries, I couldn’t locate this image.

Proposal: Provide an offline option that outputs a complete list of all required images, including their full repository paths. This would allow users to manually pull the images, save them as tar files, and copy them to the target air-gapped server.

Thank you