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]>
INCIDENT FIX. Prod's external-dns DELETED EVERY ONE OF DEV'S PUBLIC DNS RECORDS. Both
clusters ran policy: sync against the SAME Cloudflare zone with the SAME implicit
txtOwnerId (`default`), so prod believed it owned dev's records, found no matching sources,
and removed them plus their TXT registry entries. Dev recovered ~30s after prod was scaled
to 0; verified restored against Cloudflare directly (my first check went through a pfSense
override and falsely showed healthy — local resolvers are not evidence about public DNS).
THE MISS WAS MINE, and it was a failure of imagination in how I briefed every agent. I put
"never touch dev" in brief after brief and enforced it — separate kubeconfigs, verified
--limit, sha-checked dev's kubeconfig before and after. Every one of those guards held. NONE
of them covered SHARED EXTERNAL RESOURCES. Prod reconciling its OWN correctly-authored
manifests reached across a third party and destroyed dev's state. Cluster-to-cluster
isolation was verified; the dependency that mattered was cluster-to-Cloudflare.
Operator's architecture: dev -> *.dev.home.keithjackson.dev, prod ->
*.prod.home.keithjackson.dev, apex CNAME <svc>.home -> <svc>.prod.home.
PHASE 1 ONLY (this commit): prod moves to its own subdomain. DEV IS NOT MIGRATED and its
effective hostname stays home.keithjackson.dev, so dev renders byte-identically and nothing
live moves. That alone ends the collision and unblocks prod. Phase 2 (dev -> dev.home. +
apex CNAMEs) is deferred to when the operator is present: it relocates Keycloak's issuer and
12 clients' redirect URIs, forces a rolling k3s restart and kubectl SSO re-issue for every
user, and moves gitea.home. — which is BOTH the GitOps source and the current push target.
BASE_DOMAIN WAS A DEAD KNOB — it existed in cluster-vars but the status report flagged it as
referenced by nothing, because hostnames were hardcoded throughout. Now real: 141 refs.
Searched the AUTHORITATIVE reconciled set by resolving each Flux spec.path transitively via
conformance/lib/status.py — the same resolver the L0 gate uses, so "what Flux reconciles"
has one definition. 185 occurrences across 47 files in 154 reconciled files. Tokenized:
Gateway listeners, the wildcard Certificate, coredns-custom, external-dns, Keycloak
instance/realm (26 redirect URIs), oauth2-proxy, Grafana OIDC, all HTTPRoutes, Homepage's 15
links, 30 runbook_urls, unifi cloud-init, render.py's ZONE constant (which drove
--oidc-issuer-url/--cookie-domain/--whitelist-domain on every forward-auth sidecar) and 11
catalog/ ServiceDefinitions re-rendered canonically. Left alone: 43 comment/prose
occurrences and non-reconciled paths.
TWO THAT CANNOT BE TOKENIZED, flagged not forced:
- headlamp's OIDC URLs live inside a SOPS-encrypted Secret; re-encrypting rewrites the MAC
over every value and the OFFLINE harness cannot verify it (kustomize does not decrypt),
so an error would break live-dev SSO with no pre-flight proof. Prod needs its own copy
anyway — client secrets are realm-scoped.
- kube-apiserver --oidc-issuer-url is a k3s SERVER FLAG, not a manifest, so Flux can never
reach it. Done on the inventory seam instead (k3s_base_domain -> k3s_oidc_issuer_url,
overridden in group_vars/k3s_prod). Verified per host: dev keeps the default, prod gets
prod.home.
EXTERNAL-DNS OWNER, the actual incident cause: txtOwnerId is now explicit per environment —
dev renders exactly `default` (the chart default it was already using, so its existing
records stay recognised) and prod gets `prod`. The BASE default is a NON-COLLIDING SENTINEL,
deliberately not `default`, so a future environment that forgets the knob owns nothing and
can delete nothing rather than silently inheriting dev's identity.
I OVERRODE ONE AGENT DECISION against our own prior finding: it narrowed prod's
domainFilters to prod.home.keithjackson.dev as defence in depth. FINDING F-DNS1
(DECISIONS-LOG 2026-08-17) already proved a subdomain filter DROPS THE PARENT ZONE —
ExternalDNS generates the record then skips it with "no hosted zone matching record DNS
Name". Prod would have published NOTHING. Set to the ZONE (keithjackson.dev) like dev.
Isolation comes from the subdomain split plus txtOwnerId, which is what the incident
actually needed and what a domain filter cannot provide.
DEV PROVEN UNCHANGED: 11 of 12 substituting paths byte-identical; the 12th differs by
exactly one line, `+ txtOwnerId: default` — the value dev was already using implicitly.
POSITIVE CONTROLS confirm the harness is not blind: perturbing BASE_DOMAIN moves 10 of 12
hashes (the 2 that don't provably contain no hostname), perturbing the owner id moves
exactly 1. Prod's rendered output has ZERO home.keithjackson.dev references outside prod.,
and its cert renders *.prod.home.keithjackson.dev — no overlap with dev's.
L0 substitution assertions 106 -> 254; BASE_DOMAIN is no longer flagged dead. Gate PASS.
PROD REMAINS SUSPENDED (platform + 10 downstream tiers) pending review; nothing applied.
Serves: R-ENV-02, R-DNS-01, R-DNS-02, R-DNS-03, R-TLS-01.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
The plural --allowed-groups does not exist in oauth2-proxy v7.8.1; the shared
oauth2-proxy new pod and the crafty auth sidecar both crashlooped on 'unknown flag'.
The flag is the singular, repeatable --allowed-group.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Build the deferred forward-auth ENFORCEMENT for non-OIDC UIs (pihole/*arr/
qbittorrent/homepage; Crafty next), gated by Keycloak via oauth2-proxy.
- helmrelease: add `--allowed-groups=platform-admins` (R-IDP-06 floor:
authenticated AND in group) + `--skip-provider-button` (302 straight to
Keycloak; verified the interstitial 403 sign-in page otherwise).
- forward-auth-cec.yaml: interim self-authored CiliumClusterwideEnvoyConfig
ext_authz listener -> oauth2-proxy /oauth2/auth, failure_mode_allow:false,
per-route opt-in via virtualHost. TEMPLATE — not Flux-wired (PM deploys with
an L2 VIP + DNS repoint). The ext_authz stanza is verified in-cluster.
- README: document the mechanism, why per-route ext_authz on the shared Gateway
is NOT clean on Cilium 1.16.5 (machine-owned cilium-gateway-shared CEC; native
ExternalAuth/GEP-1494 in no released Cilium), the three options + recommendation,
the opt-in steps, the in-cluster proof, and the human browser test.
Keycloak `oauth2-proxy` client already carries the callback redirect URI + a
bare `groups` claim (full.path=false) — no realm change needed.
Proof (cilium-envoy v1.30.8): a standalone envoy running this exact ext_authz
stanza against the live oauth2-proxy denied unauthenticated requests (403,
oauth2-proxy sign-in body; upstream never served), while a no-filter control
route on the same backend returned 200. R-IDP-02 property holds.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
oauth2-proxy is a leaf forward-auth service that depends on Keycloak +
trusted wildcard TLS + split-horizon DNS. It lived in the gating `platform`
Flux Kustomization (wait:true), so on a cold start it Failed until those
dependencies existed, keeping the whole `platform` tier not-Ready. That in
turn blocked `platform-config` — which brings up the very Keycloak instance,
wildcard Certificate and L2 VIP oauth2-proxy needs (and previously carried
oauth2-proxy's own httproute/servicemonitor) — from ever reconciling. A
self-gating cold-start deadlock, twice-proven (DECISIONS-LOG sessions 7 & 9).
Break the cycle by moving the whole oauth2-proxy component out of the
`platform` tier into its own non-gating post-platform Flux Kustomization:
- clusters/base/oauth2-proxy.yaml: new Kustomization -> ./platform/oauth2-proxy,
dependsOn platform-config, wait:false, substituteFrom cluster-vars.
- clusters/base/kustomization.yaml: reference the new Kustomization.
- platform/kustomization.yaml: drop the oauth2-proxy component (no longer in
the gating tier).
- platform/oauth2-proxy/kustomization.yaml: pull in httproute + servicemonitor
so the full component travels together.
- platform-config/kustomization.yaml: drop the in-place oauth2-proxy
httproute/servicemonitor refs (moved with the controller).
- clusters/dev/kustomization.yaml: add the SOPS decryption patch for the new
oauth2-proxy Kustomization (it now owns the encrypted credentials Secret that
the `platform` Kustomization used to decrypt).
Now `platform` reaches Ready without oauth2-proxy; platform-config brings up
Keycloak/TLS/DNS; then oauth2-proxy reconciles against dependencies that
already exist. wait:false guarantees its health can never gate anything above
it. No config of oauth2-proxy itself changed — only its reconciliation tier.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
oauth2-proxy read the base64 cookie value as raw bytes (44) → 'must be 16/24/32 bytes'
crashloop. Regenerated cookie-secret as openssl rand -hex 16 (32 bytes). client-id +
client-secret unchanged (still match the realm oauth2-proxy client). Value tracked in
~/.config/home-k3s/keycloak-sso-secrets.txt.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Generate the 3 OIDC client secrets (SOPS-encrypted, minimal manifests) so the realm
import can inject the grafana + oauth2-proxy client secrets and both consumers match:
- platform/keycloak/keycloak-realm-clients.sops.yaml (grafana + oauth2-proxy client secrets)
- platform/oauth2-proxy/oauth2-proxy-credentials.sops.yaml (client-id/secret/cookie)
- platform/monitoring/grafana-oidc-credentials.sops.yaml (grafana client secret)
Wire each into its component kustomization and re-enable oauth2-proxy in platform +
platform-config (reverses the temp deferral now that its secret exists).
Values generated by PM per operator instruction (random; recorded out-of-repo at
~/.config/home-k3s/keycloak-sso-secrets.txt for later rotation). Encrypted via sops in the
dev container to the age recipient in .sops.yaml; plaintext never committed.
Serves: R-IDP-01, R-IDP-02, R-IDP-04, R-SEC-01.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Enable monitoring in platform/kustomization.yaml (Phase 4). Grafana admin +
Alertmanager SMTP secrets are provisioned (SOPS) and wired; Longhorn SC is up for
Prometheus/Loki PVCs. Set the Alertmanager receiver 'to:' to a valid inbox
([email protected]) so the config loads (REPLACE-ME is not a valid address);
operator can change it. NOTE: smtp_from ([email protected]) differs from
the Gmail auth user — Gmail may reject/rewrite unless a send-as alias is configured;
that only affects email delivery at alert time, not stack health.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
jakman85andClaude Opus 5