Pihole on K3S
reddit / selfhosted

----------------------------------------------------------------------
HNGLT · 2023-12-06 23:41

I have successfully setup Pihole on K3S behind an nginx ingress. My
problem is that I have no clue which IP to use for the DNS server on
my router. I feel like I've tried all the options (main machine IP,
pihole clusterIP, and the random IPs in the pihole web UI.) I'm
beginning to think it's not possible so any insight would be greatly
appreciated.

----------------------------------------------------------------------
clintkev251 · 2023-12-07 00:17

Presumably your nginx ingress is only exposing the web interface of
the pihole. You should use a load balancer to expose the service on
it's own IP so that the actual DNS resolver itself is reachable on
port 53 as expected

----------------------------------------------------------------------
HNGLT · 2023-12-07 00:26

I will try that, thank you!

----------------------------------------------------------------------
Narrow_Letterhead_96 · 2023-12-07 20:44

You're probably aware of it but DNS use the TCP/UDP protocol. And the
"pure" K8s ingress specification are only intended for HTTP traffic.
Nginx does support those protocols via ingress despite this but the
configuration is more involved. So as others said it makes sense to
use a load balancer to expose the service instead.
In my local setup I'm using Metallb https://metallb.org/ to announce
different IP addresses for my ingress and other load balanced services
to avoid potential clashes with ports. But it's not necessary

----------------------------------------------------------------------
kboda · 2023-12-08 14:49

You have two options:
1. Deploy Pihole with hostNetwork: true (no Ingress / LB needed)
2. Configure your ingress / reverse proxy solution to include port 53

In both cases:
- The router will need to use the IP address of your main machine.
- Disable resolved running on your main machine (outside k3s), so k3s
can bind port 53.