A simple kubernetes cluster using Fedora Core OS, Proxmox and k0sctl.

Client refers to the node that will be executing terraform apply to create the cluster. The Raspberry Pi can be replaced with a VM or a LXC container. The items marked Optional are needed only when you want to expose your kubernetes services to the internet via WireGuard.

A shell script is used to figure out the latest versions of coreos and k0s. This script needs to be executable by the client where you're running terraform apply.

git clone https://github.com/Naman1997/simple-fcos-cluster.git
cd simple-fcos-cluster/scripts
chmod +x ./versions.sh

I've installed haproxy on my Raspberry Pi. You can choose to do the same in a LXC container or a VM.

You need to have passwordless SSH access to a user (from the Client node) in this node which has the permissions to modify the file /etc/haproxy/haproxy.cfg and permissions to run sudo systemctl restart haproxy. An example is covered in this doc.

The variables needed to configure this script are documented in this doc.

cp terraform.tfvars.example terraform.tfvars
# Edit and save the variables according to your liking
vim terraform.tfvars

terraform init -upgrade
# You don't need to run the next command if you're using this repo for the 1st time
# Only do this if you don't want to reuse the older coreos image existing in the current dir
rm coreos.qcow2
terraform plan
# WARNING: The next command will override ~/.kube/config. Make a backup if needed.
terraform apply --auto-approve

Since HAProxy is load-balancing ports 80 and 443 (of worker nodes), we can deploy nginx-controller such that it uses those ports as an external load balancer IP.

# Update the IP address in the controller yaml
vim ./nginx-example/nginx-controller.yaml
helm install ingress-nginx ingress-nginx/ingress-nginx -n ingress-nginx --values ./nginx-example/nginx-controller.yaml --create-namespace
kubectl create deployment nginx --image=nginx --replicas=5
k expose deploy nginx --port 80
# Edit this config to point to your domain
vim ./nginx-example/ingress.yaml.example
mv ./nginx-example/ingress.yaml.example ./nginx-example/ingress.yaml
k create -f ./nginx-example/ingress.yaml
curl -k https://192.168.0.101

You'll need an account with duckdns - they provide you with a free subdomain that you can use to host your web services from your home internet. You'll also be needing a VPS in the cloud that can take in your traffic from a public IP address so that you don't expose your own IP address. Oracle provides a free tier account with 4 vcpus and 24GB of memory. I'll be using this to create a VM. To expose the traffic properly, follow this guide.

For this setup, we'll be installing wireguard on the VPS and the node that is running haproxy. The traffic flow is shown in the image below.

ansible-playbook -i hosts poweroff.yaml

haproxy -c -f /etc/haproxy/haproxy.cfg

There is a branch named 'kvm' in the repo that has steps to create a similar cluster using the 'dmacvicar/libvirt' provider. I won't be maintaining that branch - but it can be used as a frame of reference for someone who wants to create a Core OS based k8s cluster in their homelab.

Link