Helm

Website: https://helm.sh CLI Tool: helm Authentication: Kubernetes cluster credentials

Description

Helm is the package manager for Kubernetes. It helps you define, install, and upgrade Kubernetes applications using charts. Charts are packages of pre-configured Kubernetes resources. Essential for managing complex Kubernetes applications and deployments.

Commands

Chart Management

Search Charts

helm search hub <keyword>
helm search repo <keyword>
helm search repo nginx
helm search hub wordpress

Search for charts in Hub or repositories.

Show Chart Info

helm show chart <chart>
helm show values <chart>
helm show readme <chart>
helm show all <chart>

Display information about a chart.

Pull Chart

helm pull <chart>
helm pull <chart> --untar
helm pull <chart> --version 1.2.3
helm fetch <chart>

Download chart to local directory.

Create Chart

helm create <name>
helm create my-app

Create new chart with starter files.

Lint Chart

helm lint <path>
helm lint ./my-chart

Validate chart for issues.

Package Chart

helm package <path>
helm package ./my-chart
helm package ./my-chart --version 1.0.0

Package chart into archive file.

Dependency Management

helm dependency list <chart>
helm dependency update <chart>
helm dependency build <chart>

Manage chart dependencies.

Repository Management

Add Repository

helm repo add <name> <url>
helm repo add stable https://charts.helm.sh/stable
helm repo add bitnami https://charts.bitnami.com/bitnami

Add chart repository.

List Repositories

helm repo list

List configured repositories.

Update Repositories

helm repo update
helm repo update <name>

Update local repository cache.

Remove Repository

helm repo remove <name>
helm repo remove stable

Remove repository from configuration.

Release Management

Install Release

helm install <name> <chart>
helm install my-release bitnami/nginx
helm install my-app ./my-chart
helm install my-app ./my-chart --values values.yaml
helm install my-app ./my-chart --set key=value

Install chart as new release.

Install with Namespace

helm install <name> <chart> --namespace <ns>
helm install my-app ./chart --namespace production
helm install my-app ./chart --namespace prod --create-namespace

Install in specific namespace.

Dry Run

helm install <name> <chart> --dry-run --debug
helm install my-app ./chart --dry-run --debug > output.yaml

Test installation without applying.

Generate Name

helm install <chart> --generate-name
helm install bitnami/mysql --generate-name

Auto-generate release name.

List Releases

helm list
helm list --namespace <ns>
helm list --all-namespaces
helm list -A

List installed releases.

Get Release Info

helm get all <release>
helm get values <release>
helm get manifest <release>
helm get notes <release>
helm get hooks <release>

Get details about a release.

Status

helm status <release>
helm status my-release
helm status my-release --namespace production

Show status of release.

Upgrade Release

helm upgrade <release> <chart>
helm upgrade my-release bitnami/nginx
helm upgrade my-release ./chart --values values.yaml
helm upgrade my-release ./chart --set image.tag=2.0

Upgrade existing release.

Upgrade or Install

helm upgrade --install <release> <chart>
helm upgrade --install my-app ./chart

Install if not exists, upgrade if exists.

Rollback Release

helm rollback <release>
helm rollback <release> <revision>
helm rollback my-release 1

Rollback to previous or specific revision.

Uninstall Release

helm uninstall <release>
helm uninstall my-release
helm uninstall my-release --namespace production
helm delete <release>

Uninstall release and delete resources.

Keep History

helm uninstall <release> --keep-history

Uninstall but keep release history.

History and Revisions

Release History

helm history <release>
helm history my-release
helm history my-release --max 10

Show release revision history.

Get Revision

helm get values <release> --revision <num>
helm get manifest <release> --revision 2

Get specific revision details.

Templates

Template Rendering

helm template <name> <chart>
helm template my-app ./chart
helm template my-app ./chart --values values.yaml
helm template my-app ./chart --set key=value

Render templates locally without installing.

Show Template Output

helm template <name> <chart> --debug
helm template <name> <chart> --show-only templates/deployment.yaml

Debug or show specific templates.

Testing

Test Release

helm test <release>
helm test my-release
helm test my-release --logs

Run tests for a release.

Plugin Management

List Plugins

helm plugin list

List installed plugins.

Install Plugin

helm plugin install <url>
helm plugin install https://github.com/databus23/helm-diff

Install Helm plugin.

Update Plugin

helm plugin update <name>

Update plugin to latest version.

Uninstall Plugin

helm plugin uninstall <name>

Remove plugin.

Environment and Configuration

Show Environment

helm env

Display Helm environment information.

Version

helm version
helm version --short

Show Helm version.

Completion

helm completion bash
helm completion zsh
helm completion fish

Generate shell completion scripts.

Advanced Options

Wait for Resources

helm install <name> <chart> --wait
helm install <name> <chart> --wait --timeout 10m
helm upgrade <name> <chart> --wait

Wait until resources are ready.

Atomic Install

helm install <name> <chart> --atomic
helm upgrade <name> <chart> --atomic

Rollback on failure.

Force Upgrade

helm upgrade <name> <chart> --force
helm upgrade <name> <chart> --recreate-pods

Force resource updates.

Cleanup on Fail

helm install <name> <chart> --cleanup-on-fail

Delete resources if installation fails.

Verify

helm install <name> <chart> --verify
helm pull <chart> --verify

Verify package signature.

Examples

Basic Workflows

# Add repository and install chart
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update
helm install my-nginx bitnami/nginx

# Install with custom values
helm install my-app ./my-chart \
  --values prod-values.yaml \
  --set replicaCount=3 \
  --set image.tag=v2.0

# Upgrade release
helm upgrade my-app ./my-chart \
  --values prod-values.yaml \
  --set image.tag=v2.1 \
  --wait

# Check status and history
helm status my-app
helm history my-app

# Rollback if needed
helm rollback my-app 1

Development Workflow

# Create new chart
helm create my-app

# Edit chart files
# - Chart.yaml
# - values.yaml
# - templates/

# Validate chart
helm lint my-app

# Test rendering
helm template my-release ./my-app --debug

# Dry run install
helm install my-release ./my-app --dry-run --debug

# Install for real
helm install my-release ./my-app --namespace dev --create-namespace

# Test the release
helm test my-release

Production Deployment

# Install with production values
helm upgrade --install my-app ./my-chart \
  --namespace production \
  --create-namespace \
  --values values-prod.yaml \
  --set image.tag=1.2.3 \
  --wait \
  --timeout 10m \
  --atomic

# Verify deployment
helm status my-app -n production
kubectl get pods -n production

# View release values
helm get values my-app -n production

Managing Multiple Environments

# Development
helm upgrade --install my-app ./chart \
  --namespace dev \
  --values values.yaml \
  --values values-dev.yaml

# Staging
helm upgrade --install my-app ./chart \
  --namespace staging \
  --values values.yaml \
  --values values-staging.yaml

# Production
helm upgrade --install my-app ./chart \
  --namespace production \
  --values values.yaml \
  --values values-prod.yaml \
  --atomic

Chart Distribution

# Package chart
helm package ./my-chart
# Creates: my-chart-0.1.0.tgz

# Update dependencies
helm dependency update ./my-chart

# Generate index for chart repository
helm repo index .

# Push to repository (with helm-push plugin)
helm plugin install https://github.com/chartmuseum/helm-push
helm cm-push my-chart-0.1.0.tgz my-repo

Debugging

# Dry run with debug
helm install my-app ./chart --dry-run --debug

# Render specific template
helm template my-app ./chart --show-only templates/deployment.yaml

# Get rendered manifests
helm get manifest my-release

# Check values used
helm get values my-release

# View release notes
helm get notes my-release

# Test with verbose output
helm test my-release --logs

Rollback Scenarios

# List history
helm history my-release

# Rollback to previous version
helm rollback my-release

# Rollback to specific revision
helm rollback my-release 3

# Rollback with wait
helm rollback my-release 2 --wait --timeout 5m

Cleanup

# List all releases
helm list --all-namespaces

# Uninstall release
helm uninstall my-release -n production

# Uninstall but keep history
helm uninstall my-release --keep-history

# List uninstalled releases
helm list --uninstalled

# Permanently delete
helm uninstall my-release

Working with Values

# Show default values
helm show values bitnami/nginx

# Save to file
helm show values bitnami/nginx > values.yaml

# Edit values
# vim values.yaml

# Install with custom values
helm install my-nginx bitnami/nginx -f values.yaml

# Override specific values
helm install my-nginx bitnami/nginx \
  -f values.yaml \
  --set service.type=LoadBalancer \
  --set replicaCount=3

Helm Hooks

# Create chart with hooks
# Add to templates/pre-install-job.yaml:
# metadata:
#   annotations:
#     "helm.sh/hook": pre-install
#     "helm.sh/hook-weight": "0"
#     "helm.sh/hook-delete-policy": hook-succeeded

# View hooks for release
helm get hooks my-release

# Hooks execute at lifecycle events:
# - pre-install, post-install
# - pre-upgrade, post-upgrade
# - pre-delete, post-delete
# - pre-rollback, post-rollback

Notes

Charts: Packages of Kubernetes resources (templates + values)
Releases: Installed instances of charts
Repositories: Collections of charts (like package repos)
Values: Configuration parameters for charts
Templates: Go template files that generate Kubernetes manifests
Chart.yaml: Chart metadata (name, version, description)
values.yaml: Default configuration values
templates/: Directory containing Kubernetes manifest templates
charts/: Subdirectory for chart dependencies
Helm 2 vs 3: Helm 3 removed Tiller (server component)
Release Names: Must be unique within namespace
Namespaces: Releases are namespace-scoped
Atomic: Automatically rollback on failure
Wait: Wait for resources to be ready (Pods, Jobs, etc.)
Hooks: Special resources that run at specific points in lifecycle
Values Precedence: CLI --set > -f values.yaml > Chart defaults
Version: Semantic versioning (MAJOR.MINOR.PATCH)
Dependencies: Defined in Chart.yaml dependencies section
Subcharts: Charts within charts/ directory
Helm Hub: Central repository of charts (ArtifactHub)
Chart Museum: Self-hosted chart repository
OCI Registry: Helm 3 supports OCI registries for charts
Provenance: Signature verification for charts
Lint: Checks for errors and best practices
Template Functions: Sprig library + Helm-specific functions
Named Templates: Reusable template blocks with define/template
Range: Loop over lists/maps in templates
If/Else: Conditional logic in templates
With: Change scope in templates
Include vs Template: Include allows piping output
Required: Fail if value not provided
Fail Fast: Use --atomic for production deployments
Best Practices:
Use semantic versioning
Test with helm lint and dry-run
Use values.yaml for defaults
Document values with comments
Use atomic upgrades in production
Keep charts simple and focused
Version control your charts
Use namespaces for isolation

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