Replace images used by system tests to avoid Docker Hub rate limit

[windsource]

Description

Currently we use images from Docker Hub for system tests like e.g. docker.io/library/nginx. As Docker Hub as a quite strict rate limit which is bound to an IP address when not logged in, that causes problems when many users share an IP address like in a corporate environment. But as the system tests are also executed in Github Actions that problem might occur there as well, depended on how the IP address of the VM has been used before by other users.

For that reason we should avoid using images from Docker Hub and use other container registries like ghcr.io. We could mirror the required images on ghcr.io/eclipse-ankaios.

Goals

Do not use images from Docker Hub for system and integration tests anymore.

Final result

Summary

Moved images that are used in tests to ghcr.io/eclipse-ankaios and only allow those images in tests.

[windsource]

So currrently the following images are used in tests:

• docker.io/alpine:latest
• docker.io/nginx:latest