Install k3s with dashboard in Rocky9

1 Kubernetes Dashboard via NodePort and Auth Token on K3S

1.1 Description

The goal is to install and expose the Kubernetes Dashboard using NodePort and an authentication token, allowing LAN users to access it without port forwarding.

2 Setup K3S

2.1 Step 1: Upgrade and install necessary packages

dnf -y upgrade
dnf -y install setroubleshoot-server curl lsof wget tar vim git bash-completion

2.2 Step 2: Disable swap

sed -i  '/swap/d' /etc/fstab
swapoff -a

2.3 Step 3: Open necessary firewall ports

systemctl disable firewalld --now
# it is recomended to disable firewalld, so do not use this if you do not know how to handle
firewall-cmd --permanent --add-port=30443/tcp # dashboard
firewall-cmd --permanent --add-port=443/tcp   # ingress controller
firewall-cmd --permanent --add-port=6443/tcp  # API server
firewall-cmd --permanent --zone=trusted --add-source=10.42.0.0/16 # pods
firewall-cmd --permanent --zone=trusted --add-source=10.43.0.0/16 # services
firewall-cmd --reload
reboot

2.4 Step 4: Install k3s

curl -sfL https://get.k3s.io | sh
grep 'kubectl completion bash' $HOME/.bashrc || echo 'source <(kubectl completion bash)' >> $HOME/.bashrc

Check k3s version:

k3s -v
# Expected output:
# k3s version v1.30.4+k3s1 (98262b5d)
# go version go1.22.5

2.5 Step 5: Install Helm

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | sh
helm completion bash > /etc/bash_completion.d/helm
grep KUBECONFIG $HOME/.bashrc || echo 'export KUBECONFIG=/etc/rancher/k3s/k3s.yaml' >> $HOME/.bashrc

Log out and back in to apply changes, then proceed with Helm setup.

3 Setup Dashboard

3.1 Step 1: Add the Kubernetes Dashboard Helm repo and install the Dashboard

helm repo add kubernetes-dashboard https://kubernetes.github.io/dashboard/
helm upgrade --install kubernetes-dashboard kubernetes-dashboard/kubernetes-dashboard --create-namespace --namespace kubernetes-dashboard

3.2 Step 2: Expose Dashboard via NodePort

kubectl patch service kubernetes-dashboard-kong-proxy -n kubernetes-dashboard --type='merge' -p '{
  "spec": {
    "type": "NodePort",
    "ports": [
      {
        "name": "kong-proxy-tls",
        "port": 443,
        "protocol": "TCP",
        "targetPort": 8443,
        "nodePort": 30443
      }
    ],
    "selector": {
      "app.kubernetes.io/component": "app",
      "app.kubernetes.io/instance": "kubernetes-dashboard",
      "app.kubernetes.io/name": "kong"
    },
    "sessionAffinity": "None"
  },
  "status": {
    "loadBalancer": {}
  }
}'

3.3 Step 3: Create Service Account and RoleBinding for Admin Access

echo 'apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: v1
kind: Secret
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
  annotations:
    kubernetes.io/service-account.name: "admin-user"
type: kubernetes.io/service-account-token
' | kubectl apply -f -

3.4 Step 4: Retrieve the Admin User Token

kubectl get secret admin-user -n kubernetes-dashboard -o jsonpath={".data.token"} | base64 -d

Use the retrieved token to log in to the Kubernetes Dashboard at https://your.cluster.fqdn:30443

4 Uninstall Dashboard

To remove the Kubernetes Dashboard, run the following commands:

helm uninstall kubernetes-dashboard --namespace kubernetes-dashboard
kubectl get all -n kubernetes-dashboard
kubectl delete namespace kubernetes-dashboard
helm repo remove kubernetes-dashboard