Helm Charts

The package manager for Kubernetes. Bundle your application's YAML into versioned, parameterizable charts. Install, upgrade, and rollback with single commands — and share charts via Artifact Hub.

Installing Helm and Creating Your First Chart

# Install Helm
brew install helm          # macOS
curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash  # Linux

# Scaffold a new chart
helm create my-app

# Chart directory structure:
# my-app/
#   Chart.yaml          — chart metadata (name, version, appVersion)
#   values.yaml         — default configuration values
#   templates/
#     deployment.yaml   — Deployment template
#     service.yaml      — Service template
#     ingress.yaml      — Ingress template
#     hpa.yaml          — HorizontalPodAutoscaler template
#     serviceaccount.yaml
#     _helpers.tpl      — shared template helpers
#   charts/             — chart dependencies
#   .helmignore         — files to exclude from packaging

Chart Metadata and Values

# Chart.yaml
apiVersion: v2
name: my-app
description: A Helm chart for My Application
type: application
version: 0.2.0       # chart version (semver)
appVersion: "1.4.2"  # app version being packaged

# values.yaml — default values (override with -f or --set)
replicaCount: 1

image:
  repository: my-org/my-app
  pullPolicy: IfNotPresent
  tag: ""   # defaults to Chart.appVersion if empty

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: false
  className: "nginx"
  hosts:
    - host: my-app.example.com
      paths:
        - path: /
          pathType: Prefix

resources:
  requests:
    cpu: 100m
    memory: 128Mi
  limits:
    cpu: 500m
    memory: 256Mi

autoscaling:
  enabled: false
  minReplicas: 1
  maxReplicas: 5
  targetCPUUtilizationPercentage: 80

Deployment Template with Values Injection

# templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "my-app.fullname" . }}
  labels:
    {{- include "my-app.labels" . | nindent 4 }}
spec:
  {{- if not .Values.autoscaling.enabled }}
  replicas: {{ .Values.replicaCount }}
  {{- end }}
  selector:
    matchLabels:
      {{- include "my-app.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "my-app.selectorLabels" . | nindent 8 }}
    spec:
      containers:
        - name: {{ .Chart.Name }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
          imagePullPolicy: {{ .Values.image.pullPolicy }}
          ports:
            - containerPort: 8080
          resources:
            {{- toYaml .Values.resources | nindent 12 }}

Install, Upgrade, and Rollback

# Install (dry-run first to preview rendered manifests)
helm install my-app ./my-app --dry-run --debug

# Install with production overrides
helm install my-app ./my-app \
  --namespace production \
  --create-namespace \
  -f values-production.yaml \
  --set image.tag=v1.4.2

# Upgrade (or install if not exists)
helm upgrade --install my-app ./my-app \
  --namespace production \
  -f values-production.yaml \
  --set image.tag=v1.5.0 \
  --atomic \        # rollback automatically if upgrade fails
  --timeout 5m

# List releases
helm list -n production

# View release history
helm history my-app -n production

# Rollback to revision 2
helm rollback my-app 2 -n production

# Uninstall
helm uninstall my-app -n production

Chart Dependencies

# Chart.yaml — declare dependencies
dependencies:
  - name: postgresql
    version: "15.x.x"
    repository: https://charts.bitnami.com/bitnami
    condition: postgresql.enabled   # only install if values.postgresql.enabled=true
  - name: redis
    version: "19.x.x"
    repository: https://charts.bitnami.com/bitnami

# values.yaml — configure and enable/disable dependencies
postgresql:
  enabled: true
  auth:
    postgresPassword: changeme
    database: myapp

redis:
  enabled: true
  auth:
    enabled: false

# Download dependencies (creates charts/ directory)
helm dependency update ./my-app

# Install with all dependencies
helm install my-app ./my-app

Packaging and Publishing to OCI Registry

# Package the chart into a .tgz archive
helm package ./my-app
# Creates: my-app-0.2.0.tgz

# Push to an OCI registry (GitHub Container Registry)
helm push my-app-0.2.0.tgz oci://ghcr.io/my-org/helm-charts

# Install from OCI registry
helm install my-app oci://ghcr.io/my-org/helm-charts/my-app --version 0.2.0

# For a traditional Helm repo, generate index.yaml and host on GitHub Pages:
helm repo index . --url https://my-org.github.io/helm-charts
# Then users add: helm repo add my-org https://my-org.github.io/helm-charts

Helm vs Kustomize