3-Tier Application Deployment

This project demonstrates how to deploy a 3-tier application (React frontend, Node.js backend, and MongoDB database) to a Kubernetes cluster using Docker images and Helm.

Prerequisites

• Docker installed on your local machine
• Kubernetes cluster (local or cloud-based)
• Helm package manager installed on your local machine

Application Overview

The 3-tier application consists of the following components:

1. Frontend: A React application serving the user interface.
2. Backend: A Node.js application that handles the business logic and interacts with the database.
3. MongoDB: A NoSQL database for storing application data.

Getting Started

1. Build Docker Images

• Navigate to the frontend directory and build the Docker image for the React application:

  cd frontend
  docker build -t your-docker-username/frontend:1.0.0 .

• Navigate to the backend directory and build the Docker image for the Node.js application:

  cd ../backend
  docker build -t your-docker-username/backend:1.0.0 .

• Push the Docker images to a container registry (e.g., Docker Hub, ECR, GCR):

  docker push your-docker-username/frontend:1.0.0
  docker push your-docker-username/backend:1.0.0

2. Deploy with Helm

• Navigate to the 3-tier-app directory:

  cd 3-tier-app

• Update the values.yaml file with the appropriate Docker image tags and any other configuration settings.
• Install the Helm chart:

  helm install 3-tier-app .

• This will deploy the 3-tier application to your Kubernetes cluster, including the following resources:
  • Namespace (3-tier)
  • MongoDB StatefulSet
  • Secrets for Mongo Auth
  • PersistentVolume to attach to Mongo database
  • Backend Deployment
  • Frontend Deployment
  • MongoDB Service
  • Backend Service
  • Frontend Service
  • Ingress (optional)

3. Access the Application

• After the deployment is complete, you can access the frontend application using the provided ingress or load balancer URL.
• Alternatively, you can use kubectl port-forward to access the frontend service locally:

  kubectl port-forward service/frontend 8080:80

  Then, open http://localhost:8080 in your web browser.

Customization

You can customize the deployment by modifying the following files:

• helm/values.yaml: Update environment variables, resource requests/limits, and other configurations.
• helm/templates/: Modify the Kubernetes manifests for each component (Deployments, Services, Ingress, etc.).

Cleanup

To remove the 3-tier application from your Kubernetes cluster, run the following command:

helm uninstall 3-tier-app

This will delete all the resources associated with the application.

Minikube

If you're using Minikube, follow these additional steps:

1. Start Minikube:

   minikube start

2. Build Docker Images: Skip this step if you've already built and pushed the Docker images.

3. Deploy with Helm: Follow the instructions in the "Deploy with Helm" section above.

4. Access the Application: Follow the instructions in the "Access the Application" section above.

After cleaning up, you can stop the Minikube cluster by running:

minikube stop