MetalLB

Install

To set up MetalLB in your K3s environment, follow these steps:

First, create a namespace for MetalLB:

kubectl create namespace metallb-system

Next, use the Helm chart to install MetalLB. Make sure you have added the MetalLB repository to Helm and updated it:

helm repo add metallb https://metallb.github.io/metallb
helm repo update

Now, install MetalLB in the metallb-system namespace:

helm install metallb metallb/metallb --namespace metallb-system

This will install all the necessary MetalLB components into your K3s environment.

Configuration

Once MetalLB is installed, you need to configure an IP address pool from which it can allocate addresses for LoadBalancer services.

Create a configuration file metallb-config.yml with an IP range that matches your network setup:

apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  namespace: metallb-system
  name: my-ip-pool
spec:
  addresses:
  - 192.168.32.200-192.168.32.220 # Adjust IP range as per your local setup
---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  namespace: metallb-system
  name: my-l2-advertisement
spec:
  ipAddressPools:
  - my-ip-pool

Apply the configuration:

kubectl apply -f metallb-config.yml

Verify Installation

1. Check MetalLB Pods: Ensure all MetalLB pods are running:

   kubectl get pods -n metallb-system
   

2. Test LoadBalancer: Deploy a simple service with LoadBalancer type to test MetalLB:

   apiVersion: v1
   kind: Service
   metadata:
     name: test-loadbalancer
   spec:
     selector:
       app: nginx
     ports:
       - protocol: TCP
         port: 80
         targetPort: 80
     type: LoadBalancer
   

   Apply and observe the EXTERNAL-IP:

   kubectl apply -f test-loadbalancer.yml
   kubectl get services
   

Networking Notes

When using MetalLB:

• Ensure the IP address range you specify does not conflict with any other devices on the network.
• If using Layer 2 mode, all nodes in the cluster must be in the same Layer 2 domain (i.e., connected to the same switch/bridging network).

Enable Logging

For troubleshooting, you can enable logging on MetalLB to see allocation activity:

kubectl logs <metallb-controller-pod-name> -n metallb-system
kubectl logs <metallb-speaker-pod-name> -n metallb-system

Replace <metallb-controller-pod-name> and <metallb-speaker-pod-name> with the actual pod names using kubectl get pods.

Setting up MetalLB in your K3s environment allows you to simulate cloud-like external IP addressing, optimizing your configurations for a multi-server deployment.