Inject a controlled health checks failure

Add executable validation at the trust boundaries of Kubernetes liveness vs readiness for retrieval-and-generation API. Reject unknown fields where they matter, bound string sizes, and coerce only after auth/signature checks when raw bytes are security-relevant. Invariant under test: /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods. A TypeScript type or Python annotation is not runtime validation — pair them with parsers.

Automate the fixtures from setup, including a recreation of PROBE-RESTART-STORM-8. Assert both the visible error and the absence of side effects (no provider call, no queue write, no flag flip). Where metrics matter, assert label enums stay bounded.

curl -s -o /dev/null -w '%{http_code}' localhost:8080/livez # 200 curl -s -o /dev/null -w '%{http_code}' localhost:8080/readyz # 503

Document which failures are client mistakes (4xx) versus operator/config mistakes (5xx/503). Oracle still stands: vector pause → readyz 503, livez 200, no restart loop; process deadlock → livez fails → restart. Validation should make accidental “success with empty body” impossible for cluster operator during vector DB maintenance window.

Property ideas: shuffled field order, Unicode edges, maximum-length strings, and replayed timestamps. Where money, identity, or citations matter, assertion messages should cite the field name. Do not snapshot entire provider payloads in tests; assert semantically. If validation fails open “to keep the demo working,” you have inverted the lab. Tie at least one CI job to the PROBE-RESTART-STORM-8 fixture so main cannot regress silently. Re-read /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods after each new parser — convenience helpers love to bypass it.

Table-drive status codes and error codes so reviewers see coverage at a glance. Include a Unicode normalization case if user text is accepted. Verify that oversized bodies fail before CPU-heavy work. Where digests or versions are pinned, assert mismatch behavior. Keep golden files small enough to read in review. CI should fail on skipped tests that mark the incident fixture as xfail without a ticket link. In this chapter the product is Kubernetes liveness vs readiness for retrieval-and-generation API, the human stakeholder is cluster operator during vector DB maintenance window, and the incident id you design against is PROBE-RESTART-STORM-8. Re-state the oracle in your notes — vector pause → readyz 503, livez 200, no restart loop; process deadlock → livez fails → restart — and keep the invariant visible: /livez only checks process; /readyz checks vector+model deps; wrong probe kills healthy pods. Track restart_count == 0 during dep outage and ready_pods ≥ 1 when deps healthy as the scoreboard. Surface under change control: GET /livez and GET /readyz. If you only have forty minutes, finish the fixture for readyz embedded in liveness → restart storm during dependency blip before polishing UI. Promotion language stays ternary: promote, hold, or roll back based on evidence, not hope.