Pi-Hole Wildcard DNS

In order to access Kubernetes applications via my ingress projectcontour.io, I’ll use a wildcard DNS entry.

Unfortunately this isn’t a simple entry in the web UI for Pi-hole (yet?). A quick search and Brandon Rozek had documented the steps to add a wildcard DNS entry in dnsmasq. First, lets get the External-IP of our envoy LoadBalancer service. Mine shows as 10.28.28.80.

kubectl get service envoy -n projectcontour

NAME    TYPE           CLUSTER-IP     EXTERNAL-IP   PORT(S)                      AGE
envoy   LoadBalancer   10.103.158.9   10.28.28.80   80:32032/TCP,443:31610/TCP   43h

Next we will need to SSH into our Pi-Hole and create a new config file located at /etc/dnsmasq.d/03-custom-dns.conf

address=/k8s.home.fullaware.com/10.28.28.80

Next let’s restart Pi-Hole service to reload the new config.

sudo systemctl restart pihole-FTL

Now when I dig for the k8s.home.fullaware.com domain it comes up with the IP address of the envoy LoadBalancer.

;; QUESTION SECTION:
;k8s.home.fullaware.com.                IN      A

;; ANSWER SECTION:
k8s.home.fullaware.com. 0       IN      A       10.28.28.80

This allows me to create an ingress with the name asteroids.k8s.home.fullaware.com to point to my hosted app asteroids.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: asteroids-app
  namespace: asteroids
spec:
  rules:
  - host: asteroids.k8s.home.fullaware.com
    http:
      paths:
        - pathType: Prefix
          path: "/"
          backend:
            service:
              name: asteroids-app
              port:
                number: 8080