Nappa

Configuration for the nappa k3s cluster.

Overview

The cluster currently consists of three nodes:

• nappa - x86_64 NUC
• saibaman1 - Raspberry Pi 4B (aarch64)
• saibaman2 - Raspberry Pi 4B (aarch64)

nappa does all the heavy lifting here. It serves as network gateway (using dnsmasq), k3s control plane, and network storage (NFS share) for the cluster. Here's a little diagram to illustrate the network setup:

flowchart LR
    subgraph 192.168.1.x
        D(outside\nnetwork) --- A
    end
    subgraph 192.168.2.x
        A[nappa] --- B[saibaman1]
        A --- C[saibaman2]
    end

Installation (nappa)

Install NixOS, then

1. Clone this repo to /home/matt/nappa

2. To nixos-rebuild switch to the new configuration, you can use make

   make nappa
   
   # or just...
   make

Installation (saibamen)

The nix configurations at nodes/saibamanX.nix can be used to build sd card images.

1. Build the image

   make saibaman1
   
   # Or
   make saibaman2

2. Install the image on an SD card

    sudo dd if=./result/sd-image/nixos-sd-image-22.05.1700.365e1b3a859-aarch64-linux.img of=/dev/sdb bs=4096 conv=fsync status=progress

3. Put the SD card into the raspberry pi and start it up!

4. It'll take a moment for it to start up, but once it's up and running change the password

   # initial password is 'changeme'
   ssh [email protected]
   passwd

5. The agent node should get picked up by the k3s server node automatically

Bonus! How to mount the image without putting it on an SD card

1. The image has multiple partitions, use losetup to scan for them and add /dev/loop* devices:

   sudo losetup -Pf result/sd-image/nixos-sd-image-saibaman.img

2. Create a directory to mount to

   mkdir somewhere

3. Mount it!

   # /
   sudo mount /dev/loop2p2 somewhere
   
   # /boot
   sudo mount /dev/loop2p1 somewhere

Making updates to already running saibamen

Saibamen nodes have their configurations copied to /etc/nixos. Either ssh in and make changes directly, or scp changes from nappa:

# Files in /etc/nixos have the same name as they do in this repo
# They're also writable by wheel users... that means matt!
scp nodes/saibaman_base.nix saibaman2:/etc/nixos/saibaman_base.nix

Before running nixos-rebuild switch, you'll need to update nix channels:

sudo nix-channel --update

And now you're good to go!

sudo nixos-rebuild switch