Pi-Hole in HA mode (multi-pod)

Hi,

I wanted to get PiHole working as a 2-pod HA-cluster, so I can distribute them over multiple hosts. I found that the nginx persistent cookie could help. For your information, here is a working values file, based on chart version 1.7.17.

You need a central storage, available to all pods like NFS.

# values for Pi-Hole HA for nginx ingress example
replicaCount: 2

persistentVolumeClaim:
  enabled: true
  accessModes:
    - ReadWriteMany
  storageClass: nfs-client

ingress:
  enabled: true
  hosts:
    # Set your favorite hostname. It must resolve to the ingress IP-address. You could add this in PiHole itself
    # once you use it as your DNS-server. Until then, please add it to your hosts file.
    - pihole.local
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/affinity: "cookie"
    nginx.ingress.kubernetes.io/affinity-mode: "persistent"
    nginx.ingress.kubernetes.io/session-cookie-name: "route"
    nginx.ingress.kubernetes.io/session-cookie-expires: "172800"
    nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"

This should also work with Treafik, which is the default on K3S but I didn't test this:

# values for Pi-Hole HA for traefik ingress example
replicaCount: 2

persistentVolumeClaim:
  enabled: true
  accessModes:
    - ReadWriteMany
  storageClass: nfs-client

ingress:
  enabled: true
  hosts:
    # Set your favorite hostname. It must resolve to the ingress IP-address. You could add this in PiHole itself
    # once you use it as your DNS-server. Until then, please add it to your hosts file.
    - pihole.local
  annotations:
    kubernetes.io/ingress.class: traefik

serviceTCP:
  annotations:
    traefik.ingress.kubernetes.io/affinity: "true"
    traefik.ingress.kubernetes.io/session-cookie-name: "sticky"

Additionally you can force kubernetes to schedule the pods on different hosts:

antiaff:
  enabled: true
  # Here you can set the pihole release (you set in `helm install <releasename> ...`)
  # you want to avoid
  avoidRelease: pihole1
  # Here you can choose between preferred or required
  strict: true

Hope this helps!

MoJo2600 / pihole-kubernetes

Pi-Hole in HA mode (multi-pod) #77