---
title: Kubernetes
tags:
  - Developer
  - Technical documentation
  - Code
  - Programming
sidebar_position: 1
---

This guide provides step-by-step instructions for setting up a Kubernetes cluster using kind, configuring multiple nodes, and installing the Metrics Server.

## Prerequisites

Ensure you have the following installed:

- [Docker](https://docs.docker.com/get-started/get-docker/) (required for running `kind` clusters).
- [Kind](https://kind.sigs.k8s.io/docs/user/quick-start/) (Kubernetes in Docker).
- [Kubectl](https://kubernetes.io/docs/tasks/tools/) (Kubernetes command-line tool).

Additionally, ensure that Kubernetes tools are enabled in your environment by setting the following variable in your `.env` file:

```bash
# Enable Kubernetes tool
ENABLE_KUBERNETES=true
```

### 1. Creating a Kubernetes Cluster with Multiple Nodes

We will create a Kubernetes cluster using `kind` with one control plane node and two worker nodes.

#### Define the Cluster Configuration

Create a configuration file named `kind-config.yaml` with the following content:

```bash
cat > kind-config.yaml <<EOF
# three node (two workers) cluster config
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  kubeadmConfigPatches:
    - |
      kind: KubeletConfiguration
      apiVersion: kubelet.config.k8s.io/v1beta1
      kubeReserved:
        cpu: "250m"
        memory: "256Mi"
      systemReserved:
        cpu: "500m"
        memory: "512Mi"
      evictionHard:
        memory.available: "200Mi"
- role: worker
- role: worker
EOF
```

#### Create the Cluster

Run the following command to create the Kubernetes cluster:

```bash
kind create cluster --name k8s-playground --config kind-config.yaml
```

This will provision a cluster named `k8s-playground` with the specified node configuration.

### 2. Installing the Metrics Server

The Metrics Server is required for gathering resource utilization metrics like CPU and memory usage. It is essential for features such as Horizontal Pod Autoscaling.

#### Deploy the Metrics Server

Run the following command to install the Metrics Server:

```bash
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.7.2/components.yaml
```

#### Disable TLS Verification (For Local Development)

In local environments, Kubernetes nodes might not have valid certificates. To disable TLS verification, patch the deployment:

```bash
kubectl patch -n kube-system deployment metrics-server --type=json \
  -p '[{"op":"add","path":"/spec/template/spec/containers/0/args/-","value":"--kubelet-insecure-tls"}]'
```

This allows the Metrics Server to communicate with kubelets that use self-signed certificates.

### 3. Verifying the Setup

After completing the setup, verify that the cluster is running correctly:

#### Check the Cluster Nodes

```bash
kubectl get nodes
```

Expected output:

```bash
NAME                           STATUS   ROLES           AGE     VERSION
k8s-playground-control-plane   Ready    control-plane   Xs      vX.Y.Z
k8s-playground-worker          Ready    worker          Xs      vX.Y.Z
k8s-playground-worker2         Ready    worker          Xs      vX.Y.Z
```

#### Check Metrics Server Status

```bash
kubectl get deployment -n kube-system metrics-server
```

Expected output:

```bash
NAME             READY   UP-TO-DATE   AVAILABLE   AGE
metrics-server   1/1     1            1           Xs
```

#### Get Node Resource Metrics

```bash
kubectl top nodes
```

This command should return CPU and memory usage statistics for each node.

## Conclusion

You have successfully set up a multi-node Kubernetes cluster using kind and installed the Metrics Server for monitoring resource usage. This setup is useful for local development and testing Kubernetes workloads before deploying them to a production environment.