Setting Up And Installing K3S On Rocky Linux 9

Set the hostname per machine:

sudo hostnamectl set-hostname "rocky-linux-9-k3s-master-node"
sudo hostnamectl set-hostname "rocky-linux-9-k3s-worker-node"

Add the IP and hostname entries to each node’s /etc/hosts file:

sudo tee -a /etc/hosts <<EOF
10.25.96.3 rocky-linux-9-k3s-master-node
10.25.96.4 rocky-linux-9-k3s-worker-node
EOF

Disable the firewall on both the Master Node and Worker Nodes:
```
sudo systemctl disable --now firewalld
```
Install the required packages to download and install k3s:
```
sudo dnf install -y curl wget
```

Run the pipe to bash script on the Master Node only:

curl -fL https://get.k3s.io | K3S_TOKEN=LinuxRocks sh -s - server --cluster-init

Check that k3s is running on the Master Node:
```
sudo systemctl status k3s
```

Configure kubectl on the Master Node:

export KUBECONFIG=~/.kube/config
mkdir ~/.kube 2> /dev/null
sudo /usr/local/bin/k3s kubectl config view --raw > "$KUBECONFIG"
chmod 600 "$KUBECONFIG"

Permanently add the KUBECONFIG to your path:

tee -a ~/.bashrc <<EOF
# k3s path export
export KUBECONFIG=~/.kube/config
EOF

Check that the cluster is functioning on the Master Node:
```
kubectl get nodes
kubectl cluster-info
```

Connect each Worker Node:

curl -sfL https://get.k3s.io | K3S_URL=https://10.25.96.3:6443 K3S_TOKEN=LinuxRocks sh -

How to retrieve your node-token from the Master Node:
```
sudo cat /var/lib/rancher/k3s/server/node-token
```