K8S single node guide (MICROK8S)

The procedure has been tested on a ubuntu 22.04LTS 64GB Ram.

Install microk8s

If you haven't installed microk8s yet, you can install it by running the following command:

snap install microk8s --classic --channel=latest/stable
microk8s enable dns
microk8s status --wait-ready
microk8s enable hostpath-storage
microk8s enable metallb
microk8s enable ingress
microk8s enable dashboard
microk8s kubectl describe secret -n kube-system microk8s-dashboard-token ## copy the token for k8s dashboard
microk8s enable community
microk8s enable argocd
kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d ## get the token for argocd

follow https://microk8s.io/#install-microk8s

You can verify the K3s installation by checking the node status:

kubectl get nodes

You can verify the K3s installation by checking the POD status:

kubectl get pod -A

Install K8s Dashboard 

You can expose the Dashboard using a NodePort, Ingress, or LoadBalancer service, depending on your setup. By default, it uses a ClusterIP, which is not accessible externally.

To use NodePort, you can add the following to your Helm install command:

export KUBECONFIG=/etc/rancher/k3s/k3s.yaml 

helm upgrade --install kubernetes-dashboard kubernetes-dashboard/kubernetes-dashboard \ --namespace kubernetes-dashboard --create-namespace

kubectl patch svc kubernetes-dashboard-kong-proxy -n kubernetes-dashboard -p '{"spec": {"type": "NodePort"}}'

kubectl get svc kubernetes-dashboard-kong-proxy -n kubernetes-dashboard

Look for the NodePort value under the PORT(S) column. You can now access the K8s Dashboard web UI at

http://<Node_IP>:<NodePort>.

https://<Node_IP>:<NodePort>

Get Admin Token for Access

To access the Dashboard, you will need a token. Create a ServiceAccount and ClusterRoleBinding for full admin access.

Create dashboard_admin.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: dashboard-admin
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: dashboard-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: dashboard-admin
  namespace: kubernetes-dashboard

kubectl apply -f dashboard_admin.yaml

To obtain the token:

kubectl create token -n kubernetes-dashboard dashboard-admin

Install MetalLB

a. Create a Namespace for MetalLB

It’s a good practice to create a separate namespace for MetalLB:

kubectl create namespace metallb-system

b. Apply the MetalLB Manifest

Run the following command to deploy MetalLB using its official manifest:

kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.8/config/manifests/metallb-native.yaml

Make sure to check for the latest version of MetalLB on the MetalLB GitHub Releases page.

c. Check MetalLB Pods

Verify that the MetalLB components are running:

kubectl get pods -n metallb-system

You should see controller and speaker pods running.

Configure MetalLB

MetalLB needs a configuration to specify which IP address range to use for load balancing. You can create a ConfigMap with the configuration.

a. Define the IP Address Range

Create a YAML file named metallb-config.yaml with the following content, adjusting the ipAddressPool to match your network setup. For example:

apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    layer2:
      addresses:
 	  - 192.168.114.101-192.168.114.101 # machine where K3S is installed 
      - 192.168.114.200-192.168.114.210

Make sure the IP range specified is within your local network range and does not conflict with existing devices.

b. Apply the ConfigMap

Apply the configuration:

kubectl apply -f metallb-config.yaml

c. Advertise choosen addresses

Create a YAML file named metallb-advertise.yaml :

apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: example
  namespace: metallb-system
spec:
  ipAddressPools:
  - first-pool

kubectl apply -f metallb-advertise.yaml

d. Check ingress (traefik) gets loadbalancer address of the machine

kubectl get services -A

Install ArgoCD

Before installing ArgoCD, create a namespace where ArgoCD resources will live:

kubectl create namespace argocd

Install ArgoCD Using the Official Manifests

ArgoCD is installed by applying a YAML manifest. The official manifest deploys all necessary ArgoCD components, such as the API server, controller, and UI.

Run the following command to install ArgoCD:

kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

This command will install ArgoCD into the argocd namespace.

Check the ArgoCD Pods

After applying the manifest, you can check if the ArgoCD pods are running:

kubectl get pods -n argocd

You should see several pods, including argocd-server, argocd-repo-server, argocd-application-controller, and others.

Wait for everything ready.

Expose the ArgoCD Server

By default, the ArgoCD API server is only accessible inside the cluster. To access it externally, you can expose it using either a NodePort or LoadBalancer service. For a minimal installation like K3s, NodePort is typically used.

a. Expose ArgoCD with a NodePort:

Run this command to patch the argocd-server service to be of type NodePort:

kubectl patch svc argocd-server -n argocd -p '{"spec": {"type": "NodePort"}}'

To retrieve the NodePort, run the following command:

kubectl get svc -n argocd argocd-server

Look for the NodePort value under the PORT(S) column. You can now access the ArgoCD web UI at

http://<Node_IP>:<NodePort>.

https://<Node_IP>:<NodePort>

Node_IP = address/dns of the machine where is installed k3s

Get the ArgoCD Initial Admin Password

ArgoCD generates a default admin password during installation. You can retrieve it by running this command:

kubectl get secret argocd-initial-admin-secret -n argocd -o jsonpath="{.data.password}" | base64 --decode

The username is admin, and the password is what you just retrieved.

Access the ArgoCD Web UI

• URL: http://<Node_IP>:<NodePort> or http://<LoadBalancer_IP>
• Username: admin
• Password: Use the password retrieved in the previous step.

Apply the Proxy Settings (optional)

You can edit the ArgoCD deployment to add the necessary environment variables to the containers.

1. Edit the argocd-repo-server and argocd-application-controller deployments:

kubectl edit deployment argocd-repo-server -n argocd kubectl edit deployment argocd-application-controller -n argocd

1. Add the following environment variables under the spec.containers section in both deployments:

spec:
  containers:
  - name: argocd-repo-server
    env:
    - name: HTTP_PROXY
      value: "http://your-http-proxy:port"
    - name: HTTPS_PROXY
      value: "http://your-https-proxy:port"
    - name: NO_PROXY
      value: "localhost,127.0.0.1,.svc,.cluster.local,argocd-repo-server,argocd-server"

env:
    - name: HTTP_PROXY
      value: "http://squid.lnf.infn.it:3128"
    - name: HTTPS_PROXY
      value: "http://squid.lnf.infn.it:3128"
    - name: NO_PROXY
      value: "baltig.infn.it,argocd-repo-server,argocd-server,localhost,127.0.0.0/24,::1,*.lnf.infn.it,.svc,.cluster.local,10.0.0.0/8,192.168.0.0/16"  

Restart the ArgoCD Components

After updating the deployments, restart the affected components to apply the changes:

kubectl rollout restart deployment argocd-repo-server -n argocd

kubectl rollout restart deployment argocd-application-controller -n argocd