Files
home-network-k3s-impl/apps/wave-0/pihole.yaml
T
jakman85andClaude Opus 5 fd43f332d6 feat(pihole): authoritative LAN DNS for the zone on udp/53 + tcp/53 at a pinned VIP
platform/coredns/coredns-custom.yaml has always said its split-horizon is for
PODS and deferred LAN clients to "PiHole split-horizon". PiHole served no DNS:
its Service was ClusterIP with ports 80 and 4180 only. The LAN half of R-DNS-03
that docs/09 and the README's Phase 2 row both claim did not exist, so LAN
clients ran on hand-maintained per-client dnsmasq files - one went stale after
the dev decommission and cost the operator sonarr.home.keithjackson.dev. The
SOHO router that owns 192.168.2.0/24 cannot cover for it either: it strips
RFC1918 answers for public domains as rebind protection and returns NOERROR
with no answer.

EXPOSURE (apps/wave-0/pihole-dns.yaml, hand-written, placed into wave 0 by
render.py's EXTRA_UNITS - the schema has no field for a LoadBalancer Service, a
pinned lbipam VIP, a sharing key, source ranges or UDP, the same reason
apps/vms/unifi and platform/crafty hand-write theirs):
  - two Services, udp/53 and tcp/53, sharing one pinned VIP
    ${PIHOLE_DNS_VIP} = 192.168.2.23 on prod, the next free address in the
    .20-.30 pool (pool status IPsUsed 3 of 11; .20 Gateway, .21 unifi, .22
    crafty; arping from a LAN host got no reply).
  - no external-dns hostname annotation: nothing public is created, and
    platform/externaldns/ is untouched.

ANSWERS (catalog/pihole.yaml env - declarative, no reconciler): PiHole v6 takes
every FTL setting as an FTLCONF_ environment variable and treats it as
env-forced, applied ahead of pihole.toml on every cold start and read-only in
the UI. That is a real declarative entry point, which the Keycloak and CNPG
CronJob reconcilers exist precisely because their state lacks, so a reconciler
here would be ceremony. misc.dnsmasq_lines carries a wildcard
address=/<zone>/<GATEWAY_VIP> plus one longer-domain override per L4 service
(unifi, crafty-mc, pihole-dns); dnsmasq resolves overlaps by longest matching
domain, so precedence is structural and a newly onboarded Gateway-fronted
service needs no DNS change. dns.upstreams is declared too - the live pod
carried hand-set upstreams that no manifest knew about and that every restart
discarded.

externalTrafficPolicy Cluster, NOT Local, and loadBalancerSourceRanges for the
LAN restriction. Measured on prod, Cilium 1.20.1: the L2 announcer does not
filter lease candidates by which nodes hold a backend - the two Services landed
on k3s-prod-3 and k3s-prod-2 while the pod ran on k3s-prod-1 - and it keeps
renewing after the pod moves away, so with Local a reschedule leaves LAN DNS
dead indefinitely. Cluster serves the VIP from any node; the LAN restriction
moves to loadBalancerSourceRanges, which Cilium enforces in eBPF on the VIP
before load-balancing (verified by narrowing the range to exclude the test
client and back). The cost is SNAT: forwarded queries reach PiHole from the
ingress node, so PiHole's per-client rate limit is disabled in the catalog or
the whole LAN would count as one client against its 1000-per-60s default.

Proven from a LAN host (192.168.2.132) against 192.168.2.23 with the pod and
both leases on three DIFFERENT nodes: sonarr/grafana/nextcloud/keycloak/apex
-> 192.168.2.20, unifi -> .21, crafty-mc -> .22, pihole-dns -> .23, recursion
(cloudflare.com, github.com, debian.org) intact over both udp and tcp, AAAA
NODATA, NXDOMAIN outside the zone, and still answering after a forced
prod-1 -> prod-2 reschedule.

Co-Authored-By: Claude Opus 5 <[email protected]>
2026-09-14 00:57:58 -05:00

273 lines
6.9 KiB
YAML

---
# Namespace (trust zone; default-deny + policies apply)
apiVersion: v1
kind: Namespace
metadata:
name: pihole
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: pihole
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 pihole-config (R-STATE)
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pihole-config
namespace: pihole
labels:
app.kubernetes.io/name: pihole
spec:
accessModes:
- ReadWriteOnce
storageClassName: longhorn
resources:
requests:
storage: 2Gi
---
# Deployment (R-PLAT-02)
apiVersion: apps/v1
kind: Deployment
metadata:
name: pihole
namespace: pihole
labels:
app.kubernetes.io/name: pihole
spec:
replicas: 1
strategy:
type: Recreate
selector:
matchLabels:
app.kubernetes.io/name: pihole
template:
metadata:
labels:
app.kubernetes.io/name: pihole
homelab.keithjackson.dev/egress-class: internet
homelab.keithjackson.dev/auth-mode: forward-auth
annotations:
homelab.keithjackson.dev/auth-mode: forward-auth
homelab.keithjackson.dev/auth-groups: platform-admins
spec:
containers:
- name: pihole
image: pihole/pihole
ports:
- containerPort: 80
env:
- name: FTLCONF_dns_listeningMode
value: ALL
- name: FTLCONF_dns_upstreams
value: 8.8.8.8;8.8.4.4
- name: FTLCONF_dns_rateLimit_count
value: '0'
- name: FTLCONF_misc_dnsmasq_lines
value: address=/${BASE_DOMAIN}/${GATEWAY_VIP};address=/unifi.${BASE_DOMAIN}/${UNIFI_L4_VIP};address=/crafty-mc.${BASE_DOMAIN}/${CRAFTY_L4_VIP};address=/pihole-dns.${BASE_DOMAIN}/${PIHOLE_DNS_VIP}
volumeMounts:
- name: config
mountPath: /data/config
- name: oauth2-proxy
image: quay.io/oauth2-proxy/oauth2-proxy:v7.8.1
imagePullPolicy: IfNotPresent
args:
- --http-address=0.0.0.0:4180
- --reverse-proxy=true
- --provider=oidc
- --oidc-issuer-url=https://keycloak.${BASE_DOMAIN}/realms/homelab
- --upstream=http://127.0.0.1:80
- --email-domain=*
- --scope=openid email profile
- --oidc-groups-claim=groups
- --allowed-group=platform-admins
- --skip-provider-button=true
- --redirect-url=https://pihole.${BASE_DOMAIN}/oauth2/callback
- --cookie-domain=.${BASE_DOMAIN}
- --whitelist-domain=.${BASE_DOMAIN}
- --cookie-secure=true
- --pass-access-token=true
- --set-xauthrequest=true
env:
- name: OAUTH2_PROXY_CLIENT_ID
valueFrom:
secretKeyRef:
name: pihole-oauth2-proxy
key: client-id
- name: OAUTH2_PROXY_CLIENT_SECRET
valueFrom:
secretKeyRef:
name: pihole-oauth2-proxy
key: client-secret
- name: OAUTH2_PROXY_COOKIE_SECRET
valueFrom:
secretKeyRef:
name: pihole-oauth2-proxy
key: cookie-secret
ports:
- name: http
containerPort: 4180
protocol: TCP
resources:
requests:
cpu: 25m
memory: 64Mi
limits:
memory: 128Mi
securityContext:
allowPrivilegeEscalation: false
readOnlyRootFilesystem: true
capabilities:
drop:
- ALL
livenessProbe:
httpGet:
path: /ping
port: http
initialDelaySeconds: 5
periodSeconds: 15
readinessProbe:
httpGet:
path: /ping
port: http
initialDelaySeconds: 5
periodSeconds: 15
volumes:
- name: config
persistentVolumeClaim:
claimName: pihole-config
---
# Service
apiVersion: v1
kind: Service
metadata:
name: pihole
namespace: pihole
labels:
app.kubernetes.io/name: pihole
spec:
selector:
app.kubernetes.io/name: pihole
ports:
- name: port-80
port: 80
targetPort: 80
- name: authproxy
port: 4180
targetPort: 4180
---
# CiliumNetworkPolicy gateway-ingress allow (R-NET-01/02): pihole-allow-gateway-ingress
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: pihole-allow-gateway-ingress
namespace: pihole
labels:
app.kubernetes.io/name: pihole
spec:
endpointSelector:
matchLabels:
app.kubernetes.io/name: pihole
ingress:
- fromEntities:
- ingress
toPorts:
- ports:
- port: '4180'
protocol: TCP
---
# CiliumNetworkPolicy world egress allow (egress class governs the path; R-NET-05): pihole-allow-internet-egress
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
name: pihole-allow-internet-egress
namespace: pihole
labels:
app.kubernetes.io/name: pihole
spec:
endpointSelector:
matchLabels:
app.kubernetes.io/name: pihole
egress:
- toEntities:
- world
- toEndpoints:
- matchLabels:
io.kubernetes.pod.namespace: keycloak
app: keycloak
---
# HTTPRoute pihole-80 (R-TLS/R-DNS)
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
name: pihole-80
namespace: pihole
labels:
app.kubernetes.io/name: pihole
annotations:
homelab.keithjackson.dev/auth-mode: forward-auth
homelab.keithjackson.dev/auth-groups: platform-admins
spec:
parentRefs:
- name: shared
namespace: gateway
sectionName: https
hostnames:
- pihole.${BASE_DOMAIN}
rules:
- matches:
- path:
type: PathPrefix
value: /
backendRefs:
- name: pihole
port: 4180
---
# PrometheusRule SLI alerts (R-OBS-01)
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
name: pihole-slis
namespace: pihole
labels:
release: kube-prometheus-stack
app.kubernetes.io/name: pihole
spec:
groups:
- name: pihole.slis
rules:
- alert: pihole-down
expr: kube_deployment_status_replicas_available{namespace="pihole", deployment="pihole"} == 0 or absent(kube_deployment_status_replicas_available{namespace="pihole", deployment="pihole"})
for: 5m
labels:
severity: critical
service: pihole
annotations:
summary: pihole is down
description: 'pihole: its Deployment has no available/ready replica for 5m, or the signal is gone entirely (SLI: up, via kube_deployment_status_replicas_available).'