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home-network-k3s-impl/platform/keycloak/postgres-cluster.yaml
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jakman85andClaude Opus 5 0a0527e7db feat(backup): prod's off-cluster DR lands on R2 — and stops the WAL clock
Prod has been archiving WAL to `TBD-PROD-S3-BACKUP-ENDPOINT` since bootstrap.
Verified live 2026-09-07 on all three CNPG Clusters: ContinuousArchiving=False,
"unexpected failure invoking barman-cloud-wal-archive: exit status 4". Because
archive_mode is ON, that is not a degraded backup — it is a DISK-FULL CLOCK.
Postgres will not recycle a segment it has not archived, so keycloak-db's pgdata
PVC is at 579 MiB used / 4360 MiB free and climbing monotonically. When it fills,
the primary PANICs and takes SSO down, and with it kubectl OIDC, Grafana,
Headlamp, Gitea and forward-auth. Wiring the endpoint is what lets Postgres drain
the whole accumulated backlog in one pass.

THE KNOB LAYOUT (three new, one repurposed) and why it is shaped this way.

The operator created exactly ONE R2 bucket, `k3s-prod-backup`, but the two backup
tools want differently-SHAPED values: the Velero chart takes `bucket` and `prefix`
as separate fields, while CNPG's barmanObjectStore.destinationPath is one full
s3:// URL whose first path segment IS the bucket. So:

  S3_BACKUP_ENDPOINT     dev http://192.168.1.9:9000   prod https://<acct>.r2...
  S3_BACKUP_REGION       dev us-east-1                 prod auto
  VELERO_BACKUP_BUCKET   dev velero                    prod k3s-prod-backup
  VELERO_BACKUP_PREFIX   dev ""                        prod velero
  CNPG_BACKUP_PATH       dev s3://cnpg                 prod s3://k3s-prod-backup/barman

There is deliberately NO separate `S3_BACKUP_BUCKET`: CNPG's bucket already lives
inside CNPG_BACKUP_PATH, and a second knob holding the same bucket name twice is a
rotation waiting to drift. Three knobs, each shaped for its own consumer, and no
two of them can contradict each other.

TENANCY. Inside k3s-prod-backup, velero and barman get disjoint TOP-LEVEL
prefixes — s3://k3s-prod-backup/velero/ and s3://k3s-prod-backup/barman/<cluster>/
— with the bucket ROOT left empty so a misrendered prefix lands somewhere
obviously wrong instead of silently colliding. This is not tidiness: Velero ADOPTS
every backup under its location and TTL-DELETES it on retention, so an overlapping
prefix would let it reap WAL segments; and interleaving two Postgres servers' WAL
into one prefix corrupts the chain outright. Dev↔prod isolation is doubly
independent — different endpoint AND different bucket names — so neither cluster
can reach the other's objects even with a mis-substituted prefix.

DEV IS UNCHANGED, BYTE-FOR-BYTE, and that is asserted rather than assumed. Base
defaults are dev's LIVE values (verified against the running cluster: BSL
bucket=velero with NO prefix, region us-east-1; all three CNPG Clusters
ContinuousArchiving=True at s3://cnpg on the MinIO), and the dev overlay now
restates all five explicitly for the same reason LONGHORN_DATA_PATH is restated —
a silent drift in base would ORPHAN the backups dev's PROVEN restore depends on.
The empty-prefix case was the one real risk, and it is settled empirically: with
prefix "" the chart omits objectStorage.prefix from the rendered
BackupStorageLocation ENTIRELY (helm template, chart 12.1.0), so dev's live BSL is
unchanged, not merely equivalent.

R2's TWO GOTCHAS, both wired up front:
  - region must be exactly `auto`. head-bucket answers {"BucketRegion":"WNAM"},
    which is a PHYSICAL LOCATION HINT, not a signing region. This was hardcoded
    us-east-1 inside the Velero HelmRelease — correct-by-accident for MinIO, wrong
    for anything else — so it is a knob now.
  - checksumAlgorithm: "". velero-plugin-for-aws v1.14.2 bundles an AWS SDK with
    flexible checksums on by default and sends x-amz-sdk-checksum-algorithm /
    x-amz-checksum-crc32 on every PUT; R2 rejects those with HTTP 400
    InvalidArgument, failing every backup and every kopia blob upload. It must be
    PRESENT-but-empty (the plugin branches on the key existing), and the chart does
    emit an empty value — verified by rendering it. Harmless against MinIO, so it
    is unconditional rather than a fourth knob.

WHAT THIS DOES NOT DO. Velero stays SUSPENDED on prod. `spec.suspend: true` is
owned by field manager `flux` (verified: kustomize-controller's managedFields do
not include f:suspend), so server-side apply will not strip it, and nothing here
declares suspension — which would also trip R-ENV-03, since a prod overlay may
patch only cluster-vars and a Flux Kustomization's `decryption`. Unsuspending is
the operator's, after `standup.sh --s3-endpoint <r2> s3check` proves a round trip.

NO DNS KNOB IS TOUCHED. BASE_DOMAIN stays prod.home.keithjackson.dev and every
EXTERNALDNS_* value is untouched. The apex inversion on work/prod-standup-campaign
was deliberately NOT carried: this branch ports that branch's R2 reasoning knob by
knob, and merges nothing.

VERIFIED: ci/l0.sh green (flux-postbuild-substitution 272 assertions, 0 hazards,
33 knobs defined / 28 referenced, every new token resolved in BOTH overlays);
render-golden, lint, schema, spec-immutability green; touched requirement
R-STATE-03 covered.

Refs R-STATE-03, R-IDP-05, R-ENV-02, R-ENV-03.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-07 01:14:29 -05:00

90 lines
4.2 KiB
YAML

---
# Keycloak's PostgreSQL — a CloudNativePG Cluster (CR of the CNPG CRDs installed by platform/cnpg).
# CARRIED BY platform-config (dependsOn platform) so the postgresql.cnpg.io CRDs exist first (F-MON1).
#
# DR-critical (R-IDP-05): storage on the 3-replica `longhorn` StorageClass (ADR-0003) — the data
# survives node loss. CNPG creates the keycloak-db-app Secret (keys username/password) that the
# Keycloak CR consumes, plus the keycloak-db-rw/-ro/-r Services. Keycloak is stateless and rebuilds
# from this DB + the git-managed realm import (docs/15).
apiVersion: postgresql.cnpg.io/v1
kind: Cluster
metadata:
name: keycloak-db
namespace: keycloak
spec:
# Single Postgres instance on 3-replica Longhorn is acceptable for the home scale (ADR-0014:
# "single replica with DB on Longhorn + backups is acceptable"). Raise to 3 for Postgres-level HA
# as a future hardening (prod) — the storage is already 3-way replicated by Longhorn.
instances: 1
imageName: ghcr.io/cloudnative-pg/postgresql:16.4
storage:
storageClass: longhorn
size: 5Gi
bootstrap:
initdb:
database: keycloak
owner: keycloak
# Emit Postgres metrics so Prometheus scrapes DB health (R-OBS-01). The CNPG operator creates the
# PodMonitor at runtime (CRD already present from Phase-4 monitoring) — no kustomize CRD-ordering hazard.
monitoring:
enablePodMonitor: true
resources:
requests:
cpu: 100m
memory: 256Mi
limits:
memory: 512Mi
# --- Off-cluster DR backup (R-IDP-05) — CNPG-native Barman → object storage ---
# Continuous WAL archiving + periodic base backups give proper Postgres PITR (superior to a Velero
# PVC snapshot for a live DB). CNPG appends `serverName` (defaults to the Cluster name) to
# destinationPath, so objects land under ${CNPG_BACKUP_PATH}/keycloak-db/ — dev
# s3://cnpg/keycloak-db/ on the on-Proxmox MinIO, prod s3://k3s-prod-backup/barman/keycloak-db/ on
# Cloudflare R2. Both endpointURL and destinationPath are cluster-vars knobs (R-ENV-02),
# substituted by the `platform-config` Kustomization (this file sits under platform/keycloak/ but
# platform-config is the only tier that lists it as a resource — see its kustomization.yaml).
# Credentials: the scoped key from the in-namespace SOPS Secret keycloak-db-backup-credentials
# (a Pod only reads same-ns Secrets).
#
# *** archive_mode IS ON, SO A FAILING ARCHIVE COMMAND IS A DISK-FULL CLOCK, NOT A DEGRADED
# BACKUP. *** Postgres will not recycle a WAL segment it has not successfully archived, so
# whenever these two values are wrong the pgdata PVC fills monotonically until the primary
# PANICs. This is not hypothetical: prod ran from bootstrap to 2026-09-07 with
# `endpointURL: TBD-PROD-S3-BACKUP-ENDPOINT` (barman-cloud-wal-archive exit 4 on every segment)
# and had burned ~579 MiB of a 5 GiB PVC on the way to taking SSO — and with it kubectl OIDC,
# Grafana, Headlamp, Gitea and forward-auth — down with it. Never leave a placeholder here, and
# treat `ContinuousArchiving=False` on this Cluster as an availability incident, not a backup one.
backup:
retentionPolicy: "30d" # keep 30 days of base backups + WAL (PITR window); prunes older
barmanObjectStore:
destinationPath: ${CNPG_BACKUP_PATH}
endpointURL: ${S3_BACKUP_ENDPOINT}
s3Credentials:
accessKeyId:
name: keycloak-db-backup-credentials
key: ACCESS_KEY_ID
secretAccessKey:
name: keycloak-db-backup-credentials
key: ACCESS_SECRET_KEY
wal:
compression: gzip
maxParallel: 2
data:
compression: gzip
---
# Daily base backup of keycloak-db (WAL is archived continuously by the barmanObjectStore above).
# CNPG cron is 6-field (sec min hour dom mon dow). immediate:true takes a first base backup as soon
# as the schedule is created so the PITR chain has a starting point. Staggered 01:00 (nextcloud 02:00,
# semaphore 04:00, Velero 03:00) to avoid concurrent base backups hammering MinIO.
apiVersion: postgresql.cnpg.io/v1
kind: ScheduledBackup
metadata:
name: keycloak-db-daily
namespace: keycloak
spec:
immediate: true
schedule: "0 0 1 * * *"
backupOwnerReference: self
cluster:
name: keycloak-db
method: barmanObjectStore