Check if new DockerHub pricing will affect CI Runners

Overview

DockerHub has announced new pricing plans https://hub.docker.com/pricing the most worrying one that will effect us is:

Data transfer (per 6 hours)

Anonymous users 100 pulls

Authenticated users (Docker ID) 200 pulls

If I understand this correctly this would be that when our shared runners on GitLab.com will try an pull images and the user didn't specify any DOCKER_AUTH_CONFIG it will fall under the Anonymous users and we might end up being rate limited.

We have DockerHub mirroring in place which also helps with this because we don't end up relying on DockerHub that much since most images are available in the mirror.