Whisker showed an empty UI on 2026-06-28. Root cause: whisker-backend dials
goldmane:7443 over a long-lived gRPC stream; when that stream dropped during a
transient CNI/DNS blip (right after k8s-node5 finished its v1.35.6 upgrade, its
pod resolver briefly timed out on the kube-dns ClusterIP) the Go gRPC resolver
got WEDGED — spamming "failed to stream flows" / "code = Unavailable: dns ...
i/o timeout" forever, never reconnecting. The operator ships whisker-backend
with NO liveness probe, so nothing restarted it; the live UI stayed blank until
a manual `kubectl delete pod`. (The durable aggregator is a separate pod and
was unaffected — only Whisker's ~60-min live view went dark.)
Whisker is operator-managed (Whisker CR), so we can't inject a liveness probe.
Instead add a watchdog so this never needs a manual restart again:
- whisker-watchdog CronJob (every 10 min) + least-privilege SA/Role/RoleBinding
(calico-system only: pods get/list/delete, pods/log get).
- It restarts the whisker pod only when whisker-backend logs >=10 goldmane-
connection errors in 11m AND Goldmane is Ready (the Goldmane-Ready guard
avoids restart-thrash during a real Goldmane outage).
- Self-tested: a manual run reports "whisker-backend healthy: 0 ... errors"
and does not restart.
Docs: runbook gains a "Whisker UI empty" troubleshooting entry + a self-heal
note; the stale 2026-06-25 "digest never posted" known-state block is updated
to Resolved (digest posts to #alerts, lastSuccessfulTime current); CLAUDE.md
flow-trail bullet gains the whisker-wedge gotcha.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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