jakman85andClaude Opus 5
fc7ec01628
Jackett failed on 2026-09-30 in the most expensive way available: HTTP 200 and a
plausible page. oauth2-proxy answers an unauthenticated XHR with a 302 to Keycloak
rather than a 401; the browser follows it silently against a live SSO session and
the call resolves 200 carrying a 44 KB HTML dashboard where the app's JavaScript
wanted JSON. The user is never re-prompted, reloading never helps, and every uptime
check stays green. `jackett-down` watches replicas_available, which was 1 throughout.
The reason nothing alerted turns out not to be a missing rule. Measured on prod:
count by (__name__) ({__name__=~"oauth2_proxy.*"})
oauth2_proxy_requests_in_flight => 2
Two series, both from the SHARED forward-auth Deployment. The six per-app gate
sidecars (crafty, jackett, pihole, qbittorrent, radarr, sonarr) publish nothing at
all: no --metrics-address, so the metrics listener never starts; no `metrics`
container port; no ServiceMonitor or PodMonitor selects them. The alert the incident
calls for — sustained auth redirects to an authenticated user — is therefore NOT
WRITABLE, and writing it anyway would have shipped a rule that is present,
evaluating, permanently silent and indistinguishable from health.
So alert on the condition that made the incident invisible, from families that ARE
scraped:
OAuth2ProxyGateUnobserved
count by (namespace) (kube_pod_container_info{container="oauth2-proxy"})
unless
count by (namespace) (up{container="oauth2-proxy"})
kube_pod_container_info is kube-state-metrics (a declared scrape owner) and sees the
container whether or not it exports anything; `up` is UNIVERSAL and carries a
`container` label for any target, so the rule needs no advance knowledge of what job
name a future per-app scrape picks. Nothing in it touches oauth2_proxy_*, so it
cannot be inert for the reason it is reporting. Run verbatim against live prod it
returns six namespaces and correctly excludes oauth2-proxy. It clears per namespace
as each gate gains a real scrape.
Also:
- promtool companion test pinning all four states: fires unscraped, quiet when
scraped, honours for:1h, and STOPS once a scrape appears under a different job name.
- runbooks/oauth2-proxy-auth-failures.md — tell the gate's refusal from the group
check from the app's own login from an XHR that silently got HTML, with the
2026-09-30 jackett trace as the worked example and the Loki queries to use while
there are no metrics. Registered in the configMapGenerator and README.
- runbooks/README.md gains an inert-alerts row for the unscraped sidecars.
Rejected: an alert on the shared proxy's oauth2_proxy_requests_total ratio. It needs
a conformance/ SCRAPE_OWNERS entry (human approval) and, decisively, would not have
fired on this incident — the shared instance is not in any sidecar-gated app's data
path and its current pods have proxied nothing. It would have looked like coverage
and been none.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
21 lines
1.2 KiB
YAML
21 lines
1.2 KiB
YAML
---
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# oauth2-proxy component. Rendered by its OWN post-platform Flux Kustomization
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# (clusters/base/oauth2-proxy.yaml, dependsOn platform-config, wait:false) — NOT by the gating
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# `platform` tier. The httproute + servicemonitor (Gateway API / monitoring CRs) travel WITH the
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# controller here now, rather than being referenced in-place from platform-config: the CRDs they
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# need (gateway.networking.k8s.io, monitoring.coreos.com) are registered by platform and platform
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# is Ready before this tier's platform-config dependency completes, so ordering holds.
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apiVersion: kustomize.config.k8s.io/v1beta1
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kind: Kustomization
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resources:
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- namespace.yaml
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- helmrepository.yaml
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- helmrelease.yaml
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- oauth2-proxy-credentials.sops.yaml
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- httproute.yaml # forward-auth sign-in/callback ingress (was referenced in-place by platform-config)
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- servicemonitor.yaml # Prometheus scrape (was referenced in-place by platform-config)
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# Alerting on whether the gates are OBSERVABLE at all. Travels with the servicemonitor above
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# for the same reason it does: monitoring.coreos.com CRDs are registered by the `platform`
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# tier, which is Ready before this tier's platform-config dependency completes.
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- auth-visibility-alerts.yaml
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