Epic Goal

• The goal is to support metrics federation for user-defined monitoring via the /federate Prometheus endpoint (both from within and outside of the cluster).

Why is this important?

• It is already possible to configure remote write for user-defined monitoring to push metrics outside of the cluster but in some cases, the network flow can only go from the outside to the cluster and not the opposite. This makes it impossible to leverage remote write.
• It is already possible to use the /federate endpoint for the platform Prometheus (via the internal service or via the OpenShift route) so not supporting for UWM doesn't provide a consistent experience.
• If we don't expose the /federate endpoint for the UWM Prometheus, users would have no supported way to store and query application metrics from a central location.

Scenarios

1. As a cluster admin, I want to federate user-defined metrics using the Prometheus /federate endpoint.
2. As a cluster admin, I want that the /federate endpoint to UWM is accessible via an OpenShift route.
3. As a cluster admin, I want that the access to the /federate endpoint to UWM requires authentication (with bearer token only) & authorization (the required permissions should match the permissions on the /federate endpoint of the Platform Prometheus).

Acceptance Criteria

• CI - MUST be running successfully with tests automated
• Release Technical Enablement - Provide necessary release enablement details and documents.
• Documentation - information about the recommendations and limitations/caveats of the federation approach.
• User can federate user-defined metrics from within the cluster
• User can federate user-defined metrics from the outside via the OpenShift route.

Dependencies (internal and external)

1. None

Previous Work (Optional):

1. None

Open questions:

1. None

Done Checklist

• CI - CI is running, tests are automated and merged.
• Release Enablement <link to Feature Enablement Presentation>
• DEV - Upstream code and tests merged: <link to meaningful PR or GitHub Issue>
• DEV - Upstream documentation merged: <link to meaningful PR or GitHub Issue>
• DEV - Downstream build attached to advisory: <link to errata>
• QE - Test plans in Polarion: <link or reference to Polarion>
• QE - Automated tests merged: <link or reference to automated tests>
• DOC - Downstream documentation merged: <link to meaningful PR>