Helm

What is Helm Package Manager?

Helm helps you manage your application as a single package on a Kubernetes cluster.

To run an application, we often need to use multiple Kubernetes objects, such as:

• Deployments
• Services
• Ingress
• Backend Objects:
  • Volumes
  • Secrets
  • ConfigMaps
  • DaemonSets
  • StatefulSets
  • etc.

Using Helm, we can convert these definition files into a single Helm chart.

This means an application becomes a bundle of different objects packaged into a Helm chart, allowing us to deploy the application as a single suite.

This means we deploy the application as a single suit.

Helm provides commands to manage applications, such as:

• helm install <app>
• helm uninstall <app>
• helm upgrade <app> (change settings or versions)
• etc.

Key Components of Helm in Kubernetes

. Charts
- A package of pre-configured Kubernetes resources for applications. 2. Repositories
- Storage locations for managing and sharing Helm charts. 3. Releases
- Instances of charts running in a Kubernetes cluster. 4. Values
- Configuration settings that customize charts during deployment.

Chart Structure

wordpress-chart/
├── templates/
│   ├── ingress.yaml
│   ├── mysql-deployment.yaml
│   ├── mysql-service.yaml
│   ├── NOTES.txt
│   ├── persistent-volume-claims.yaml
│   ├── secret.yaml
│   ├── wordpress-deployment.yaml
│   ├── wordpress-service.yaml
├── Chart.yaml
├── values.yaml

1. Create a Chart

   • Use the command: helm create myapp

2. Content of the Chart

   • Create a templates folder and add values.yaml files.

3. Deploy and Manage

   • Deploy the chart: helm install <release-name> <chart-path>
   • Upgrade the chart: helm upgrade <release-name> <chart-name> -f values.yaml
   • Uninstall the chart: helm uninstall <release-name>
   • List releases: helm list

4. Helm Repositories

   • Add a repository: helm repo add bitnami https://charts.bitnami.com/bitnami
   • Update repositories: helm repo update
   • Install a chart from a repository: helm install my-nginx bitnami/nginx