Helm Charts

Helm Charts

Helm is the package manager for Kubernetes. It simplifies deploying and managing complex applications by bundling Kubernetes manifests into reusable charts.

Helm Chart Structure

  mychart/
  ├── Chart.yaml          # Chart metadata
  ├── values.yaml         # Default configuration values
  ├── templates/
  │   ├── deployment.yaml
  │   ├── service.yaml
  │   ├── ingress.yaml
  │   ├── configmap.yaml
  │   └── _helpers.tpl    # Template helpers
  └── README.md

Chart.yaml

  apiVersion: v2
  name: myapp
  description: My application Helm chart
  type: application
  version: 0.1.0      # Chart version
  appVersion: "1.0.0"  # Application version
  dependencies:
    - name: postgresql
      version: "12.x.x"
      repository: "https://charts.bitnami.com/bitnami"

values.yaml

  replicaCount: 3

  image:
    repository: myapp
    tag: "latest"
    pullPolicy: IfNotPresent

  service:
    type: ClusterIP
    port: 80

  ingress:
    enabled: true
    hosts:
      - host: myapp.example.com
        paths:
          - path: /
            pathType: Prefix

  resources:
    limits:
      cpu: 500m
      memory: 256Mi
    requests:
      cpu: 250m
      memory: 128Mi

Helm Commands

  # Install a chart
  helm install myrelease bitnami/nginx

  # Install with custom values
  helm install myrelease ./mychart -f custom-values.yaml

  # Upgrade a release
  helm upgrade myrelease ./mychart --set replicaCount=5

  # Rollback
  helm rollback myrelease 1

  # List releases
  helm list

  # Uninstall
  helm uninstall myrelease