Description
This is the live half of TSO-0164 (the OTLP ACK probe recipe). Rob authorised it on 2026-10-09: one run of just probe-otlp-ack against the OTLP gateway of the lab Grafana Cloud stack named in LOOP.md, at most 3 requests in total, using the stack’s OTLP write credential read by path. This repository is public, so the task records the shape only (status, Content-Type, body length, protobuf yes or no), never the endpoint tenant, the user or the credential. If either signal returns a non-empty, non-protobuf 2xx, file a high-priority bug for the ACK guard with that evidence.
Acceptance Criteria
- #1 The probe ran once against the gateway; per-signal status, Content-Type, body length and protobuf-decodable result are recorded in this task’s notes with no identifiers
- #2 If any 2xx body is non-empty and not protobuf, a high-priority bug task exists citing this evidence; otherwise the notes state that the guard is safe against this gateway
Definition of Done
- #1 just check passes (the full gate; it is what CI enforces)
- #2 just gen leaves no diff (only if a generated artifact’s inputs changed)
- #3 just –fmt –check passes and every new recipe has a # doc comment and a [group(…)]
Implementation Plan
Run exactly one allowlisted first-token probe on reviewed landed code, count emitted signal requests, allow fallback only on 401/403 and only if first run consumed one request, otherwise abort before exceeding three. Record public-safe ACK shapes and file a guard bug only for nonempty nonprotobuf 2xx.
Implementation Notes
Live ACK probe on reviewed landed SHA d5f023fadc688a486d8ea9f9d9b33bfd23d92e81, once, exit 0, two requests. Logs: status 204, Content-Type empty, body length 0, protobuf-decode true. Metrics: status 200, Content-Type application/x-protobuf, body length 0, protobuf-decode true. First credential succeeded, no fallback and no additional request. Neither response has a nonempty nonprotobuf 2xx body, so the guard is safe against these observed gateway ACK shapes. This proves ACK response shape only, not backend ingestion, partial acceptance semantics or future availability; no guard bug is warranted by this evidence. No endpoint/user/token/body captured in tracked notes.
loop20: 1 implementation attempts; Done after acceptance, landed code and green composed gate. Earlier superseded/cancelled CI runs are not passes.
Final Summary
loop20 landed evidence d5f023fadc688a486d8ea9f9d9b33bfd23d92e81. One approved live probe, two requests, no fallback. Logs204 empty type/body and metrics200 protobuf type/empty body; both decode true. Guard safe against observed ACK shapes only; not ingestion/future-availability proof. Independent guarded receipt review PASS; no code change so CodeRabbit skipped. Final composed just check on actual shipped SHA129945fb3230f1c5d8a1127ad3e3c7faa2c514f4 passed, unchanged tree. Exact CI e96e74e31e2df4c697435dd4b7a32315e0e02f41 run38003933710 ci-success succeeded; no production diff outside backlog from that tested code. Helm absent-not-required (no landed chart change). Just formatting passed. Generated-input DoD is not applicable or covered by gate; no generator drift or weakened test claimed.