Packer: Pi-Hole

A script for building a Pi Hole image using Packer.

Prerequisites

First, install Packer on your system. For Debian/Ubuntu based systems:

curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
sudo apt-get update && sudo apt-get install packer

Then you need to install the ARM image plugin. This requires a working install of Go.

git clone https://github.com/solo-io/packer-builder-arm-image
cd packer-builder-arm-image
go mod download
go build

There is an alternative Packer ARM plugin if you want more control: https://github.com/mkaczanowski/packer-builder-arm.

After building the plugin, you need to copy the binary to a location where Packer can pick it up (e.g. $HOME/.packer.d/plugins). However, you will most likely run the build a root, so keep that in mind:

sudo mkdir -p /root/packer.d/plugins/
sudo mv packer-builder-arm-image /root/packer.d/plugins/

Lastly, you also need to instrall kpartx and qemu:

sudo apt install kpartx qemu-user-static

Building

You need to create a config file named vars.json which contains a bit of configuration:

{
  "user_name": "<user>",
  "user_password": "<password>",
  "user_public_key": "<public ssh key for user>",
  "pi_password": "<another password>",
  "pihole_web_password": "<yet anotehr password>",
  "host_name": "piholr",
  "ipv4_address": "10.0.0.10/24"
}

Variable	Description
user_name	If not empty a new user with this name will created.
user_password	The password for the new user.
user_public_key	The SSH public key for the new user.
pi_password	A new password for the default pi user.
pihole_web_password	The password for the Pi-hole web interface.
host_name	The host name (default: pihole).
ipv4_address	The IPv4 address of the machine (used by Pi-hole).
ipv6_address	The IPv6 address of the machine. Can be left empty.

When you've created the vars.json file you can build the image with:

sudo make build

The resulting image output-arm-image/image can be burned to a micro-SD card.