This readme file provides step-by-step instructions to configure MetalLB, a load balancer implementation for Kubernetes, on a Raspberry Pi cluster. MetalLB allows you to allocate external IP addresses to services running within your cluster.

Before you begin, ensure that you have the following:

• Raspberry Pi cluster with Kubernetes installed.
• Access to the Raspberry Pi cluster via kubectl command-line tool.
• Helm and kubectl installed on your local machine.

Follow the steps below to configure MetalLB on your Raspberry Pi cluster:

1. Create a Kubernetes namespace for MetalLB by adding the following configuration to your Terraform file (main.tf):

   provider "helm" {
     kubernetes {
       config_path = "~/.kube/config"
     }
   }
   
   provider "kubernetes" {
     config_path    = "~/.kube/config"
     config_context = "pi"
   }
   
   resource "kubernetes_namespace" "metallb" {
     metadata {
       name = "metallb"
     }
   }

2. Install the MetalLB Helm chart by adding the following configuration to your Terraform file (main.tf):

   resource "helm_release" "metal_lb" {
     name       = "metallb"
     repository = "https://metallb.github.io/metallb"
     chart      = "metallb"
     namespace  = kubernetes_namespace.metallb.metadata[0].name
   
     set {
       name  = "labels.pod-security.kubernetes\\.io/enforce"
       value = "privileged"
     }
   
     set {
       name  = "labels.pod-security.kubernetes\\.io/audit"
       value = "privileged"
     }
   
     set {
       name  = "labels.pod-security.kubernetes\\.io/warn"
       value = "privileged"
     }
   
     set {
       name  = "speaker.secretName"
       value = "memberlist"
     }
   }

3. Create a file named metal-lb-config.yaml on your local machine and copy the following YAML configuration into it:

   ---
   # Metallb address pool
   apiVersion: metallb.io/v1beta1
   kind: IPAddressPool
   metadata:
     name: ip-pool
     namespace: metallb
   spec:
     addresses:
       - 192.168.1.180-192.168.1.240
   ---
   # L2 configuration
   apiVersion: metallb.io/v1beta1
   kind: L2Advertisement
   metadata:
     name: l2-advert
     namespace: metallb
   spec:
     ipAddressPools:
       - ip-pool

4. Add the following Terraform configurations to your main.tf file to deploy the metal-lb-config.yaml file as Kubernetes manifests:

   data "kubectl_file_documents" "metal_lb" {
     content = file("metal-lb-config.yaml")
   }
   
   resource "kubectl_manifest" "metal_lb" {
     for_each  = data.kubectl_file_documents.metal_lb.manifests
     yaml_body = each.value
   }

5. Now lets test our deployment, Create a file named nginx-deployment.yaml on your local machine and copy the following YAML configuration into it:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
   spec:
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
           - name: nginx
             image: nginx:1
             ports:
               - name: http
                 containerPort: 80
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: nginx
   spec:
     ports:
       - name: http
         port: 80
         protocol: TCP
         targetPort: 80
     selector:
       app: nginx
     type: LoadBalancer

6. Add the following Terraform configurations to a new file called test-deployment.tf file to deploy the nginx-deployment.yaml file as Kubernetes manifests:

   data "kubectl_file_documents" "test-deployment" {
   content = file("test-deployment.yaml")
   }
   
   resource "kubectl_manifest" "test-deployment" {
   for_each  = data.kubectl_file_documents.test-deployment.manifests
   yaml_body = each.value
   }

7. Run kubectl get svc nginx should show you the nginx service with an external Ip to access the instance

   kubecl get svc nginx
   NAME    TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)        AGE
   nginx   LoadBalancer   10.43.217.91   192.168.1.181   80:30415/TCP   48m