I would like to access images stored in registry.redhat.io from a GitHub Workflow as part of my CI process triggered by pull request events.

As documented by GitHub:

With the exception of GITHUB_TOKEN, secrets are not passed to the runner when a workflow is triggered from a forked repository.

This means that, even if I configure my GitHub repository to provide a secret containing the auth token required by registry.redhat.io, this will be omitted when a contributor creates a pull request from their fork.

GitHub does provide some sort of authentication for its workflows via GITHUB_TOKEN. Maybe this can be leveraged to generate an ephemeral token for registry.redhat.io?

The concrete use case i have is this. I have a repo which contain Tekton Task definitions. These Tasks use container images from different registries. As part of the GitHub Workflow used to validate pull requests, the Tekton Task definitions are executed against a kind cluster. Currently, I cannot both use images from registry.redhat.io in one of my Task definitions and test that Task definition as part of a GitHub Workflow executed on pull requests.