Ok. Docker is also a convenient container registry. And its independent of ALL of those infrastructures so if i cancel any of them or move elsewhere, Im still good. So why should I not pay for Docker?

> independent of ALL of those infrastructures

I want the container registry a local hop away from the thing using the images, not across the public internet…

That doesn't make a difference. With most of the stuff, images will only be pulled when they are not locally present or stale. Ie pull if not present in K8. So doesnt make any difference.

In a cluster of any size worth discussing, this is hundreds if not thousands of pulls over public infrastructure vs private, which is a bad trade off in the vast majority of cases.

Where should they be cached for CI builds? How about caching them in the registry? Makes sense to me.

That depends on your CI service and pipeline...

OK, so I'm going to enable caching. Why? I could just have one I can download from.

Edit: hmm, maybe I do want a cache, because of the public containers they depend on. https://docs.gitlab.com/runner/configuration/speed_up_job_ex...

> independent of ALL of those infrastructures

Ok, so where is Docker Hub hosted? Do they run their own data centers?

Irrelevant, because if they move at some point in the future, users won't have to change anything.