# K0s

## Install Single Node Cluster

<https://docs.k0sproject.io/v0.11.0/k0s-single-node/>

```bash
# Allow all traffic in
firewall-cmd --set-default-zone=trusted

# Install k0s cli
curl -sSLf https://get.k0s.sh | sudo sh

# Setup the config
k0s config create > k0s.yaml

# Install single node cluster controller/node
k0s install controller -c k0s.yaml --enable-worker

# Start and enable the service
systemctl enable --now k0scontroller

# Enable bash completion
echo 'source <(k0s completion bash)' >>~/.bashrc
source ~/.bashrc

# Make an admin user
mkdir ~/.kube
k0s kubeconfig create --groups "system:m asters" admin > ~/.kube/config

# Remove the taint that prevents scheduling on the controller
kubectl edit node
```

## Install Multi Node Cluster

<https://docs.k0sproject.io/v0.11.0/k0s-multi-node/>

Install the controller on the controller machine

```bash
# Allow all traffic in
firewall-cmd --set-default-zone=trusted

# Install k0s cli
curl -sSLf https://get.k0s.sh | sudo sh

# Save default config
k0s config create > k0s.yaml

# Install the controller
k0s install controller

# Enable the controller
systemctl enable --now k0scontroller

# Enable bash completion
echo 'source <(k0s completion bash)' >>~/.bashrc
source ~/.bashrc

# Make an admin user (scp ~/.kube/config to your operator machine)
# kubectl config set-context --current --namespace kube-system
mkdir ~/.kube
k0s kubeconfig create --groups "system:masters" admin > ~/.kube/config

# Generate a worker join token
k0s token create --role=worker > worker0-token
```

Now on the worker machine, install the worker

```bash
# Allow all traffic in
firewall-cmd --set-default-zone=trusted

# On the operator, copy the token file from the controller to the worker
scp vm-k0s-controller:worker0-token vm-k0s-worker:token-file

# Install k0s cli
curl -sSLf https://get.k0s.sh | sudo sh

# Join the worker
k0s install worker --token-file token-file

# Start the service
systemctl enable --now k0sworker

# Enable bash completion
echo 'source <(k0s completion bash)' >>~/.bashrc
source ~/.bashrc
```

## Uninstall

```bash
systemctl stop k0scontroller
k0s reset
reboot
```

## Install Metallb

<https://docs.k0sproject.io/v1.26.0+k0s.0/examples/metallb-loadbalancer/>

1. Create a VLAN with a dedicated subnet for Metallb. Disable DHCP.
2. Attach this new VLAN to your worker nodes
3. Assign the worker nodes an address within the created network.
4. Install Metallb. Check `active/software_k0s/metallb-configmap.yaml` before proceeding.

```bash
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/namespace.yaml
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/metallb.yaml

kubectl apply -f active/software_k0s/metallb-configmap.yaml
```

### Uninstall Metallb

```bash
kubectl delete -f active/software_k0s/metallb-configmap.yaml

kubectl delete -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/metallb.yaml
kubectl delete -f https://raw.githubusercontent.com/metallb/metallb/v0.10.2/manifests/namespace.yaml
```