Cilium Feature Proposal

Describe the feature you'd like
We aim to introduce a pervasive packet trace identifier that allows for distributing tracing across networks. These flows (referred to as tagged flows) will trigger adding the ID value to the flow event messages.

Describe your proposed solution
We created a proof of concept which parses trace identifiers at TC ingress points, stores it to a per-CPU array-map, and emits the stored trace identifiers with the corresponding flow events.

There is a more thorough description and documentation of this feature, our investigations, and future milestones in our CFP document: CFP: Distributed Packet Tracing