PiHole as LXC Container on Proxmox

Deploying PiHole as LXC Container

Although I’m super happy with my PiHole setup as it is now, I’ve wondering if I should deploy a second PiHole (as a fallback whenever I need to update the original one). BEfore I even start with that, I’d like to explore how would all that work on a LXC setup. Let’s get started.

Configure NAT/PAT-Bridge

This is not a requisite! I’m just experimenting with my Proxmox VE and would like to explore how NAT/PAT virtual bridges work. Skip this step completely if your network configuration is different.

• Allow NAT/PAT masquerading on /etc/network/interfaces, on the PVE host.
• Restart network to apply changes using ifreload -a

Download CTE Template and install PiHole

• On your PVE GUI, click on your Datacenter and navigate to Local Directory > CTE Templates > look for your preferred OS-template and download it.
• Click on Create CT and choose your hardware specs according to PiHole’s Prerequisites.
• Given that I’m using a special network configuration for this task, these are my network parameters:

IPv4 is the address that we have established for destination NAT/PAT. Gateway is the address of the Bridge Interface where the container is connected to (vmbr1 in my case).

• Start up container, install updates and download curl and PiHole.

apt update && sudo apt upgrade -y
apt install curl
curl -sSL https://install.pi-hole.net | bash

• Click through installer and set up your options. Once installed, change login password and set up a couple of local DNS records.

Test Setup

• Since NAT/PAT is enabled, we should be able to access PiHole’s GUI by calling http:<vmbr0-IP>:80/admin. For the same reason, clients should be able to access PiHole for DNS resolution by calling <vmbr0-ip>:53.
• On a host attached to vmbr0, change network settings so that DNS Server calls now vmbr0’s IP. Test hostname resolution and internet connectivity.
• While checking the queries on the PiHole GUI, I noticed that almost all come from vmbr1’s IP - this is because of my NAT/PAT configuration. My hosts belong to vmbr0’s network, but due to the NAT/PAT translation, all DNS queries seem to come from a vmbr1 IP.