feat(apps): onboard nextcloud (Phase 6) — first CNPG-DB + OIDC-target patterns

Onboard nextcloud (docs/13 row 7): public, DR-critical file sync backed by an
external PostgreSQL. Establishes the reusable CNPG-DB pattern for later DB-backed
services.

- catalog/nextcloud.yaml: ServiceDefinition (image nextcloud:31-apache :80, public,
  internet, data 20Gi longhorn @/var/www/html, backup daily-offcluster, auth oidc
  +platform-admins, ingress nextcloud.home.keithjackson.dev, dependency
  nextcloud-db:5432). Uses schema 1.2.0 env for the Postgres connection, break-glass
  admin, trusted-domain + OVERWRITE* proxy settings.
- apps/nextcloud-db.yaml: CloudNativePG Cluster in a dedicated nextcloud-db namespace
  (modeled on keycloak-db; no default-deny, mirroring the verified keycloak posture),
  inheritedMetadata stamps app.kubernetes.io/name=nextcloud-db so the rendered egress
  CNP matches. initdb consumes a pre-provisioned owner secret.
- apps/nextcloud-db-app.sops.yaml + apps/nextcloud-bootstrap-secret.sops.yaml: SOPS
  (age) — shared DB password mirrored across the two namespaces (Pods cannot read a
  Secret cross-namespace), plus the break-glass local admin.
- apps/nextcloud.yaml: rendered manifests (catalog/render.py --no-image-automation).
- apps/kustomization.yaml: wire in the four new resources.

OIDC realm-client wiring DEFERRED (WS-APPS step-3 escape hatch): editing the reconciled
realm import in platform-config risks the running Keycloak realm / whole platform-config
apply, and nextcloud OIDC needs post-install occ steps with no first-class env — nextcloud
comes up INSTALLED on the break-glass local admin (as Gitea did); the Keycloak client is a
follow-up. Off-cluster backup awaits Velero/OQ-BKP (intent declared).

Gates: render --selftest PASS; other apps byte-identical; ci l0 17/17; l1 3/3; lint clean.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

apps/nextcloud.yaml

@@ -0,0 +1,264 @@
+---
+# Namespace (trust zone; default-deny + policies apply)
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: nextcloud
+  labels:
+    homelab.keithjackson.dev/app-namespace: 'true'
+    gateway-access: shared
+  annotations:
+    homelab.keithjackson.dev/backup-policy: daily-offcluster
+---
+# Default-deny baseline (R-NET-01): deny all, allow only DNS
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: default-deny
+  namespace: nextcloud
+  labels:
+    homelab.keithjackson.dev/baseline: default-deny
+spec:
+  podSelector: {}
+  policyTypes:
+  - Ingress
+  - Egress
+  ingress: []
+  egress:
+  - to:
+    - namespaceSelector:
+        matchLabels:
+          kubernetes.io/metadata.name: kube-system
+    ports:
+    - protocol: UDP
+      port: 53
+    - protocol: TCP
+      port: 53
+---
+# PVC nextcloud-data (R-STATE)
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: nextcloud-data
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  accessModes:
+  - ReadWriteOnce
+  storageClassName: longhorn
+  resources:
+    requests:
+      storage: 20Gi
+---
+# Deployment (R-PLAT-02)
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nextcloud
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  replicas: 1
+  strategy:
+    type: Recreate
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: nextcloud
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: nextcloud
+        homelab.keithjackson.dev/egress-class: internet
+        homelab.keithjackson.dev/auth-mode: oidc
+      annotations:
+        homelab.keithjackson.dev/auth-mode: oidc
+        homelab.keithjackson.dev/auth-groups: platform-admins
+    spec:
+      containers:
+      - name: nextcloud
+        image: nextcloud:31-apache
+        ports:
+        - containerPort: 80
+        env:
+        - name: POSTGRES_HOST
+          value: nextcloud-db-rw.nextcloud-db.svc.cluster.local
+        - name: POSTGRES_DB
+          value: nextcloud
+        - name: POSTGRES_USER
+          value: nextcloud
+        - name: POSTGRES_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: nextcloud-bootstrap
+              key: db-password
+        - name: NEXTCLOUD_ADMIN_USER
+          valueFrom:
+            secretKeyRef:
+              name: nextcloud-bootstrap
+              key: admin-username
+        - name: NEXTCLOUD_ADMIN_PASSWORD
+          valueFrom:
+            secretKeyRef:
+              name: nextcloud-bootstrap
+              key: admin-password
+        - name: NEXTCLOUD_TRUSTED_DOMAINS
+          value: nextcloud.home.keithjackson.dev
+        - name: OVERWRITEHOST
+          value: nextcloud.home.keithjackson.dev
+        - name: OVERWRITEPROTOCOL
+          value: https
+        - name: OVERWRITECLIURL
+          value: https://nextcloud.home.keithjackson.dev
+        volumeMounts:
+        - name: data
+          mountPath: /var/www/html
+      volumes:
+      - name: data
+        persistentVolumeClaim:
+          claimName: nextcloud-data
+---
+# Service
+apiVersion: v1
+kind: Service
+metadata:
+  name: nextcloud
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  selector:
+    app.kubernetes.io/name: nextcloud
+  ports:
+  - name: port-80
+    port: 80
+    targetPort: 80
+---
+# CiliumNetworkPolicy egress allow (R-NET-02): nextcloud-allow-nextcloud-db-5432
+apiVersion: cilium.io/v2
+kind: CiliumNetworkPolicy
+metadata:
+  name: nextcloud-allow-nextcloud-db-5432
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  endpointSelector:
+    matchLabels:
+      app.kubernetes.io/name: nextcloud
+  egress:
+  - toEndpoints:
+    - matchLabels:
+        app.kubernetes.io/name: nextcloud-db
+        k8s:io.kubernetes.pod.namespace: nextcloud-db
+    toPorts:
+    - ports:
+      - port: '5432'
+        protocol: TCP
+---
+# CiliumNetworkPolicy gateway-ingress allow (R-NET-01/02): nextcloud-allow-gateway-ingress
+apiVersion: cilium.io/v2
+kind: CiliumNetworkPolicy
+metadata:
+  name: nextcloud-allow-gateway-ingress
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  endpointSelector:
+    matchLabels:
+      app.kubernetes.io/name: nextcloud
+  ingress:
+  - fromEntities:
+    - ingress
+    toPorts:
+    - ports:
+      - port: '80'
+        protocol: TCP
+---
+# CiliumNetworkPolicy world egress allow (egress class governs the path; R-NET-05): nextcloud-allow-internet-egress
+apiVersion: cilium.io/v2
+kind: CiliumNetworkPolicy
+metadata:
+  name: nextcloud-allow-internet-egress
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+spec:
+  endpointSelector:
+    matchLabels:
+      app.kubernetes.io/name: nextcloud
+  egress:
+  - toEntities:
+    - world
+---
+# HTTPRoute nextcloud-80 (R-TLS/R-DNS)
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: nextcloud-80
+  namespace: nextcloud
+  labels:
+    app.kubernetes.io/name: nextcloud
+  annotations:
+    homelab.keithjackson.dev/auth-mode: oidc
+    homelab.keithjackson.dev/auth-groups: platform-admins
+spec:
+  parentRefs:
+  - name: shared
+    namespace: gateway
+    sectionName: https
+  hostnames:
+  - nextcloud.home.keithjackson.dev
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /
+    backendRefs:
+    - name: nextcloud
+      port: 80
+---
+# ServiceMonitor (R-OBS-01)
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: nextcloud
+  namespace: nextcloud
+  labels:
+    release: kube-prometheus-stack
+    app.kubernetes.io/name: nextcloud
+spec:
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: nextcloud
+  namespaceSelector:
+    matchNames:
+    - nextcloud
+  endpoints:
+  - port: metrics
+    interval: 30s
+---
+# PrometheusRule SLI alerts (R-OBS-01)
+apiVersion: monitoring.coreos.com/v1
+kind: PrometheusRule
+metadata:
+  name: nextcloud-slis
+  namespace: nextcloud
+  labels:
+    release: kube-prometheus-stack
+    app.kubernetes.io/name: nextcloud
+spec:
+  groups:
+  - name: nextcloud.slis
+    rules:
+    - alert: nextcloud-down
+      expr: up{job="nextcloud"} == 0
+      for: 5m
+      labels:
+        severity: critical
+        service: nextcloud
+      annotations:
+        summary: nextcloud is down
+        description: 'nextcloud has been unreachable for 5m (SLI: up).'