Deploy Custom Application in Kubernetes using Helm

To deploy your custom application in a Kubernetes cluster using Helm, follow these steps to create a Helm chart and configure it to deploy the application:

Step-by-Step Guide

1. Set Up Your Environment

• Make sure Helm is installed on your local machine and configured to interact with your Kubernetes cluster.

• Verify the Helm version and check connectivity to the cluster:
  

   helm version
   kubectl get nodes
  

2. Create a New Helm Chart

• Use Helm to scaffold a new chart for your application:
  

   helm create myapp
  

• This creates a directory named myapp with a predefined folder structure (templates, values.yaml, etc.).

3. Customize values.yaml

• The values.yaml file holds the default configuration values for your chart. Modify it to reflect the settings for your application. For example:
  • Set the Docker image details (e.g., repository and tag).
  • Define service ports, replicas, and other configurations.

• Example:
  

   image:
     repository: your-docker-repo/your-app
     tag: "latest"
   service:
     type: ClusterIP
     port: 80
  

4. Edit Kubernetes Manifests in templates Directory

• The templates directory contains YAML templates for various Kubernetes resources.
• Edit these files to fit your application requirements:
  • deployment.yaml for deployment configurations.
  • service.yaml for exposing your application.
  • Add additional YAML files if you need specific resources like ConfigMaps, Ingress, or Secrets.
• For example, customize deployment.yaml with your application's container image and other specifications.

5. Package and Install the Helm Chart

• Before deploying, package the chart to confirm that everything is structured correctly:
  

   helm package myapp
  

• Install the Helm chart in your Kubernetes cluster:
  

   helm install myapp ./myapp
  

• This command deploys your application using the configurations defined in your chart.

6. Verify the Deployment

• Check that the application pods and services are running:
  

   kubectl get pods
   kubectl get svc
  

• To debug any issues, use:
  

   kubectl describe pod <pod-name>
   kubectl logs <pod-name>
  

7. Expose the Application (Optional)

• If you want external access to your application, configure an Ingress resource or use a LoadBalancer service type. Update the service.yaml and ingress.yaml files accordingly in your templates directory.

8. Update the Application

• For any changes to the chart or configuration, use the helm upgrade command:
  

   helm upgrade myapp ./myapp
  

9. Uninstall the Application (Cleanup)

• To remove the application when it’s no longer needed:
  

   helm uninstall myapp
  

Summary of Key Components in Helm Chart

• values.yaml: Default values for your chart.
• templates/: Directory containing Kubernetes manifests for deployment, service, and other resources.
• Chart.yaml: Metadata about the chart (name, version, etc.).

This process gives you flexibility to manage and version control your deployments, making it easier to maintain and scale the application in Kubernetes.