k8s-clusters

This repository contains the configuration, scripts, and other goodies for building and managing my kubernetes clusters (right now, that's just my home cluster). I share the source with you so you can make exactly the same mistakes as I do.

Setup

Setup the pre-commit hooks before you change anything!

pip install pre-commit
pre-commit install --install-hooks
pre-commit autoupdate

Provision Machines

Before we interact with the cluster, we have some manual work to do.

Manual Preparation

Currently, my nodes are Arch Linux machines on bare metal
- Nodes must be ready to be controlled via Ansible
  - Have python3 installed
  - Need to be ssh-able from a controller (my workstation)
    - curl -L files.lyte.dev/key.pub >> ~/.ssh/authorized_keys

Automated Provisioning

Setup Ansible on the controller (from ./ansible)
- ansible-galaxy install -r requirements.yml --force
Verify Ansible can reach hosts (from ./ansible)
- ansible all -i inventory/hosts.yml --list-hosts
- ansible all -i inventory/hosts.yml -m ping
Use Ansible to build the cluster as configured on all nodes (from ./ansible)
- ansible-playbook -i inventory/hosts.yml ./build-k3s-cluster

And the cluster is up! If you want to interact with it from your controller, you can do this:

ansible -i ansible/inventory/hosts.yml $REMOTE_HOST -m fetch \
  -a "src=/etc/rancher/k3s/k3s.yaml dest=./k3s-cluster-config.kubeconfig.yaml flat=yes"
# TODO: this did not work for me
# env KUBECONFIG="~/.kube/config:./k3s-cluster-config.kubeconfig.yaml" \
# kubectl config view --flatten | sed "s/127.0.0.1/$REMOTE_HOST/" > ~/.kube/new-config

Copy the cluster information from the ./k3s-cluster-config.kubeconfig.yaml file into your existing ~/.kube/config (or just copy it there if it doesn't exist)
- You will need to edit the host from localhost/127.0.0.1 to the correct host

Automated Teardown

ansible-playbook -i inventory/hosts.yml ./nuke-k3s-cluster

Setting up Flux

Install the flux CLI on a machine that can kubectl into the shiny, new cluster
- paru -S flux-bin
- or curl -s https://fluxcd.io/install.sh | sudo bash
- https://fluxcd.io/docs/installation/
Run the pre-flight check (you must have ~/.kube/config setup!)
- flux check --pre
Create the flux-system namespace
- kubectl create namespace flux-system --dry-run=client -o yaml | kubectl apply -f -

Add the sops-age encryption key to the namespace

pass home-k8s-cluster | grep age-secret-key | aws '{printf $2}' | \
  kubectl --namespace flux-system create secret generic sops-age \
  --from-file=age.agekey=/dev/stdin

Install Flux

flux bootstrap git --url=$SSH_REPO_URL --branch=master \
  --path=./cluster --private-key-file=$FLUX_PRIVATE_KEY_FILE

To Do & Status

Flux setup needs to be finalized
- Currently having issues getting it to bootstrap since it seems to think my secrets file is supposed to be a k8s resource
How am I going to handle highly-available storage?
cert-manager with CloudFlare?
external-dns with CloudFlare?
I still need to figure out my overall cluster structure
- Since my goal is to have full redundancy, I believe I need at least 2 control plane nodes, which since I need an odd number means 3 control plane nodes, and at least 2 worker nodes. This means 5 nodes total. I should be able to use some of my rpi4s in the cluster, probably as control plane nodes.
- Where/how is storage attached?
I need to figure out a migration plan from my current Netlify + Custom DDNS + Docker Compose setup
- I should be able to do something like the following:
  - Setup all applications on the cluster using some dummy domain
  - Make sure everything works with the dummy domain
  - Change dummy domain to real domain
  - Change domain's nameserver to cloudflare
  - Should be all set!
I want to look into Talos/Sidero + PXEBoot, since that could remove a lot of the ansible stuff?
k3s has a decent amount of magic AFAICT, so I'd like to learn more about it and all its components so I better understand what my system is actually doing

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