Helm

The package manager for Kubernetes — simplify deployments with reusable charts.

Key Concepts

• Chart — A package of pre-configured K8s resources
• Release — An instance of a chart running in a cluster
• Repository — A collection of charts
• Values — Configuration parameters for customization

Essential Commands

# Add a repository
helm repo add bitnami https://charts.bitnami.com/bitnami

# Search for charts
helm search repo nginx

# Install a chart
helm install my-release bitnami/nginx

# List releases
helm list

# Upgrade a release
helm upgrade my-release bitnami/nginx --set replicaCount=3

# Rollback
helm rollback my-release 1

# Uninstall
helm uninstall my-release

Creating Your Own Chart

# Create chart scaffold
helm create my-chart

# Chart structure
my-chart/
  Chart.yaml          # Chart metadata
  values.yaml         # Default values
  templates/          # K8s manifest templates
    deployment.yaml
    service.yaml
    ingress.yaml
    _helpers.tpl      # Template helpers

Best Practices

• Use semantic versioning for charts
• Document all values in values.yaml
• Use _helpers.tpl for reusable template logic
• Test charts with helm lint and helm template
• Store charts in a chart repository (ChartMuseum, OCI)

Learning Resources

Getting Started

Resource	Description
Helm Documentation	Official Helm documentation
Create Your First Helm Chart	Bitnami guide on authoring charts
Authoring Awesome Charts	Official Helm guide on chart authoring
Kompose Guide	Translate docker-compose to Helm

Chart Repositories

Repository	Description
Helm Hub	Official Helm Hub
Bitnami Charts	Popular application charts
Kubeapps	Helm chart discovery hub
ChartCenter	Central Helm chart repository by JFrog
Cloudsmith	Managed package repository with free tier
Fairwinds Charts	Fairwinds chart hub

Helm Plugins

Plugin	Description
Helm Diff	Show diff of helm upgrade/rollback
Helm Secrets	Manage secrets safely
Helm S3	Fetch charts from S3
Helm GCS	Manage charts on Google Cloud Storage
Helm Datree	Enforce best practices and policies
Helm Schema Gen	Generate values.schema.json
Helm Teller	Manage deployment configuration securely

Helm Tools

Tool	Description
Helmfile	Declarative spec for deploying Helm charts
Helmsman	Terraform-like desired state for Helm
Reckoner	Simplify multiple Helm releases
Monocular	Web UI for searching charts
ChartMuseum	Self-hosted Helm chart repository
Helmify	Generate Helm charts from K8s YAML
Helm Docs	Auto-generate chart documentation
werf	CLI tool for CI/CD with extended Helm

Useful Applications

Application	Repository
GitLab Omnibus	charts.gitlab.io
JupyterHub	jupyterhub.github.io/helm-chart
Harbor Registry	github.com/goharbor/harbor-helm
OpenStack	github.com/openstack/openstack-helm
Elasticsearch/Kibana	github.com/elastic/helm-charts
Kafka	github.com/Landoop/kafka-helm-charts

Community

Channel	Link
Slack	#helm-users on K8s Slack
Stack Overflow	kubernetes-helm tag

Hook Lifecycle

Helm provides hooks to intervene at specific lifecycle points:

Hook	Timing
pre-install	After templates render, before resources created
post-install	After all resources loaded into Kubernetes
pre-delete	Before deletion request resources deleted
post-delete	After release resources deleted
pre-upgrade	After templates render, before update
post-upgrade	After resources upgraded
pre-rollback	After templates render, before rollback
post-rollback	After resources modified
test	When Helm test subcommand invoked