Fedora CoreOS is tied/related to 3 major things:
- Upstream git repositores like github.com/coreos/ignition, github.com/coreos/rpm-ostree, github.com/coreos/fedora-coreos-config, etc.
- Actual releases of Fedora CoreOS via the pipeline
- Downstream RHEL CoreOS
- Github (specifically the coreos namespace)
- quay.io, specifically the coreos-assembler namespace
- CoreOS CI Jenkins
- Fedora infrastructure
- OpenShift Prow
Most active repositories in the coreos/ project are hooked up to at least one of 3 CI systems, being CoreOS CI Jenkins, Github Actions, or OpenShift Prow. These 3 are the ones we are focusing on.
It is what we use on various repositories, and is how FCOS is released today via the pipeline. We have a lot of institutional knowledge around this and it gives us a place where we can easily control the end-to-end interactions. Jenkins is a well understood tool.
This is deployed in CentOS CI which is a bare metal OpenShift cluster where nested virt is enabled.
Also of key relevance is the coreos-ci-lib repository.
Prow is heavily oriented towards testing OpenShift container components. However, as of recently we enabled nested virt on the build02 GCP cluster, which means we can create "container native" flows that still test the OS with coreos-assembler.
A specific reason to include Prow is that it contains tight integration with OpenShift which we need for RHCOS, and it is also maintained and staffed by a team that e.g. also contains a budget and secrets for running infrastructure in public clouds.
Examples can be found in the openshift/release coreos/ folder.
Free for small scale, nice to use. This is a good option for per-repository specific things that don't need centralization.
A good use case is e.g. validating rustfmt.
Examples:
A key aspect of Fedora CoreOS as well as RHEL CoreOS is coreos-assembler. As of today, we build it in quay.io and deliver it that way in the quay.io/coreos-assembler namespace. The list of administrators for this namespace is managed independently of anything else. If you think you need administrator access, file a ticket or ask on #coreos:fedoraproject.org on Matrix.
Since this pull request, there is also a FCOS-oriented "buildroot" container that can be used in all CI systems.
Maintained by a distinct team. FCOS and our container images include most content derived from Koji/Bodhi etc.
It would potentially make sense to have some of our containers built in Fedora too, such as coreos-assembler. That would give us e.g. multi-arch. But that is not being pursued currently.