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Avesh
Avesh

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Multi-Node Kubernetes Cluster Setup with KIND

#kubernetes #devops #100daysofcode #tutorial

Setting up a multi-node Kubernetes cluster is crucial for testing and simulating production-grade environments. Kubernetes in Docker (KIND) provides a lightweight and straightforward way to deploy multi-node clusters on your local machine using Docker containers as cluster nodes. This guide walks you through the process of creating a multi-node Kubernetes cluster using KIND with hands-on examples.

What is KIND?

KIND (Kubernetes IN Docker) is a tool that runs Kubernetes clusters inside Docker containers. It is primarily used for:

  • Testing Kubernetes clusters locally.
  • Simulating multi-node setups.
  • Building and testing Kubernetes controllers or applications.

Why Use KIND?

  • Lightweight and easy to set up.
  • No need for virtual machines.
  • Perfect for local development and testing.

Prerequisites

  1. Docker installed on your machine.
  2. KIND installed. Install it using go or download a pre-built binary: 
 curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.20.0/kind-linux-amd64 chmod +x ./kind sudo mv ./kind /usr/local/bin/kind
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  1. kubectl installed for interacting with the Kubernetes cluster: 
 curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl" chmod +x kubectl sudo mv kubectl /usr/local/bin/
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Step 1: Define the Multi-Node KIND Cluster Configuration

Create a configuration file for your multi-node cluster. For example, save the following YAML as kind-config.yaml:

kind: Cluster apiVersion: kind.x-k8s.io/v1alpha4 nodes: - role: control-plane - role: worker - role: worker networking: apiServerAddress: "127.0.0.1" apiServerPort: 6443
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Explanation:

  • Control Plane: Manages the cluster (scheduler, API server, etc.).
  • Workers: Nodes that run your application workloads.
  • Networking: Configures the API server endpoint for local access.

Step 2: Create the KIND Cluster

Run the following command to create your multi-node cluster:

kind create cluster --config kind-config.yaml --name multi-node-cluster
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Expected Output: 

Creating cluster "multi-node-cluster" ... ✓ Ensuring node image (kindest/node:v1.28.0) 🖼 ✓ Preparing nodes 📦 📦 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 Set kubectl context to "kind-multi-node-cluster" You can now use your cluster with: kubectl cluster-info --context kind-multi-node-cluster
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Step 3: Verify the Cluster

Check the nodes in the cluster:

kubectl get nodes
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Expected Output: 

NAME STATUS ROLES AGE VERSION multi-node-cluster-control-plane Ready control-plane 2m25s v1.28.0 multi-node-cluster-worker Ready <none> 2m10s v1.28.0 multi-node-cluster-worker2 Ready <none> 2m10s v1.28.0
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Step 4: Deploy a Sample Application

Create a sample deployment and service to verify the cluster setup. Save the following YAML as nginx-deployment.yaml:

apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.21 ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: nginx-service spec: selector: app: nginx ports: - protocol: TCP port: 80 targetPort: 80 type: LoadBalancer
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Apply the configuration:

kubectl apply -f nginx-deployment.yaml
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Step 5: Access the Application

List services to get the service's endpoint:

kubectl get services
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Expected Output: 

NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 5m nginx-service LoadBalancer 10.96.42.123 localhost 80:30001/TCP 2m
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Access the application by navigating to http://localhost:30001 in your browser.

Step 6: Simulate Node-Specific Workloads

You can deploy workloads to specific nodes using node selectors. Update the deployment to target the worker nodes. Edit the nginx-deployment.yaml:

spec: template: spec: nodeSelector: kubernetes.io/hostname: multi-node-cluster-worker
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Apply the changes:

kubectl apply -f nginx-deployment.yaml
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Step 7: Clean Up

When you're done, delete the cluster:

kind delete cluster --name multi-node-cluster
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Best Practices for KIND Clusters

  1. Resource Limits: Ensure Docker has enough resources allocated (CPU and memory).
  2. Ingress Setup: Use the KIND ingress addon for testing routing rules.
  3. Cluster Customization: Leverage KIND’s configuration options for advanced networking and storage setups.
  4. Continuous Testing: Integrate KIND clusters into CI/CD pipelines for testing.

Conclusion

With KIND, setting up a multi-node Kubernetes cluster is simple and effective for local testing. It’s a lightweight solution that enables developers and DevOps engineers to test workloads, configurations, and networking in a simulated multi-node environment. Follow this hands-on guide to deploy your own clusters and enhance your Kubernetes skills!

Top comments (2)

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favethetechlady profile image
Favour Chuku •

NICE ONE

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Avesh •

Thanks!