Helm Cheat Sheet

Quick reference for Helm 3 — the package manager for Kubernetes. Covers chart structure, templating, lifecycle commands, hooks, and common patterns.

Related: Kubernetes Cheat Sheet | kubectl Advanced

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Repository Management

Command	Description
helm repo add bitnami https://charts.bitnami.com/bitnami	Add a chart repository
helm repo add stable https://charts.helm.sh/stable	Add legacy stable repo
helm repo update	Update repo index
helm repo list	List configured repos
helm repo remove bitnami	Remove a repo
helm search repo nginx	Search repos for a chart
helm search repo nginx --versions	Show all available versions
helm search hub wordpress	Search Artifact Hub

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Chart Lifecycle

Install

Command	Description
helm install my-release bitnami/nginx	Install a chart
helm install my-release bitnami/nginx -n production	Install in specific namespace
helm install my-release bitnami/nginx -f values.yaml	Install with custom values
helm install my-release bitnami/nginx --set replicaCount=3	Install with inline overrides
helm install my-release bitnami/nginx --set-string image.tag="1.25"	Force value as string
helm install my-release bitnami/nginx --version 15.0.0	Install specific chart version
helm install my-release ./my-chart	Install from local chart directory
helm install my-release my-chart.tgz	Install from local archive
helm install my-release bitnami/nginx --dry-run --debug	Dry run (render templates only)
helm install my-release bitnami/nginx --wait --timeout 5m	Wait for pods to be ready
helm install my-release bitnami/nginx --create-namespace -n new-ns	Create namespace if missing

Upgrade

Command	Description
helm upgrade my-release bitnami/nginx	Upgrade a release
helm upgrade my-release bitnami/nginx -f values-prod.yaml	Upgrade with new values
helm upgrade my-release bitnami/nginx --reuse-values --set replicas=5	Keep existing values, override one
helm upgrade --install my-release bitnami/nginx	Install if not exists, upgrade if it does
helm upgrade my-release bitnami/nginx --atomic	Auto-rollback on failure
helm upgrade my-release bitnami/nginx --force	Force resource update

WARNING

--reuse-values merges with existing values. Without it, all values reset to chart defaults plus your overrides. This catches people off guard.

Rollback

Command	Description
helm rollback my-release	Rollback to previous revision
helm rollback my-release 3	Rollback to specific revision
helm rollback my-release 3 --wait	Rollback and wait for readiness

Uninstall

Command	Description
helm uninstall my-release	Delete a release
helm uninstall my-release -n production	Delete from specific namespace
helm uninstall my-release --keep-history	Delete but keep history

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Inspect & Debug

Command	Description
helm list	List installed releases in current namespace
helm list -A	List releases across all namespaces
helm list --pending	Show pending releases
helm status my-release	Show release status
helm history my-release	Show release revision history
helm get values my-release	Show user-supplied values
helm get values my-release --all	Show all computed values
helm get manifest my-release	Show rendered Kubernetes manifests
helm get notes my-release	Show release notes
helm get hooks my-release	Show release hooks
helm show chart bitnami/nginx	Show chart metadata
helm show values bitnami/nginx	Show default values.yaml
helm show readme bitnami/nginx	Show chart README
helm template my-release bitnami/nginx -f values.yaml	Render templates locally (no install)

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Chart Structure

my-chart/
├── Chart.yaml          # Chart metadata (name, version, dependencies)
├── Chart.lock          # Locked dependency versions
├── values.yaml         # Default configuration values
├── values.schema.json  # JSON Schema for values validation
├── templates/
│   ├── _helpers.tpl    # Template helpers and partials
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── configmap.yaml
│   ├── hpa.yaml
│   ├── serviceaccount.yaml
│   ├── NOTES.txt       # Post-install instructions
│   └── tests/
│       └── test-connection.yaml
├── charts/             # Dependency chart archives
├── crds/               # Custom Resource Definitions
└── .helmignore         # Files to exclude from packaging

Chart.yaml

apiVersion: v2
name: my-app
description: My application Helm chart
type: application          # application or library
version: 1.2.0             # Chart version (SemVer)
appVersion: "3.5.1"        # Application version
dependencies:
  - name: postgresql
    version: "12.x.x"
    repository: "https://charts.bitnami.com/bitnami"
    condition: postgresql.enabled
  - name: redis
    version: "17.x.x"
    repository: "https://charts.bitnami.com/bitnami"
    condition: redis.enabled

---

Templating Essentials

Built-in Objects

Object	Description
.Release.Name	Release name
.Release.Namespace	Release namespace
.Release.IsUpgrade	True if upgrade/rollback
.Release.IsInstall	True if install
.Release.Revision	Revision number
.Chart.Name	Chart name
.Chart.Version	Chart version
.Chart.AppVersion	App version
.Values	Values from values.yaml and overrides
.Capabilities.KubeVersion	Kubernetes version
.Template.Name	Current template file path

Common Template Functions

# String functions
name: {​{ .Values.name | upper }}
name: {​{ .Values.name | lower }}
name: {​{ .Values.name | title }}
name: {​{ .Values.name | quote }}
name: {​{ .Values.name | trim }}
name: {​{ .Values.name | replace "old" "new" }}
name: {​{ printf "%s-%s" .Release.Name .Chart.Name }}

# Default values
image: {​{ .Values.image | default "nginx:latest" }}

# Required values (fails if missing)
password: {​{ required "password is required" .Values.password }}

# Conditionals
{​{- if .Values.ingress.enabled }}
  # ingress resources
{​{- end }}

# Ternary
replicas: {​{ ternary 3 1 .Values.production }}

# Loops
{​{- range .Values.env }}
- name: {​{ .name }}
  value: {​{ .value | quote }}
{​{- end }}

# With (change scope)
{​{- with .Values.nodeSelector }}
nodeSelector:
  {​{- toYaml . | nindent 2 }}
{​{- end }}

Helper Templates (_helpers.tpl)

{​{/* Generate standard labels */}}
{​{- define "my-app.labels" -}}
helm.sh/chart: {​{ include "my-app.chart" . }}
app.kubernetes.io/name: {​{ include "my-app.name" . }}
app.kubernetes.io/instance: {​{ .Release.Name }}
app.kubernetes.io/managed-by: {​{ .Release.Service }}
{​{- end }}

{​{/* Generate a fullname with release */}}
{​{- define "my-app.fullname" -}}
{​{- printf "%s-%s" .Release.Name .Chart.Name | trunc 63 | trimSuffix "-" }}
{​{- end }}

{​{/* Usage in templates */}}
metadata:
  name: {​{ include "my-app.fullname" . }}
  labels:
    {​{- include "my-app.labels" . | nindent 4 }}

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Hooks

Hooks run at specific points in the release lifecycle.

Annotation Value	When It Runs
pre-install	Before any resources are installed
post-install	After all resources are installed
pre-upgrade	Before any resources are upgraded
post-upgrade	After all resources are upgraded
pre-delete	Before any resources are deleted
post-delete	After all resources are deleted
pre-rollback	Before a rollback
post-rollback	After a rollback
test	When helm test is run

Hook Example — Database Migration

apiVersion: batch/v1
kind: Job
metadata:
  name: {​{ include "my-app.fullname" . }}-migrate
  annotations:
    "helm.sh/hook": pre-upgrade
    "helm.sh/hook-weight": "0"
    "helm.sh/hook-delete-policy": hook-succeeded
spec:
  template:
    spec:
      restartPolicy: Never
      containers:
        - name: migrate
          image: {​{ .Values.image.repository }}:{​{ .Values.image.tag }}
          command: ["npm", "run", "migrate"]
          env:
            - name: DATABASE_URL
              valueFrom:
                secretKeyRef:
                  name: {​{ include "my-app.fullname" . }}-secrets
                  key: database-url

Hook Delete Policies

Policy	Description
hook-succeeded	Delete after hook succeeds
hook-failed	Delete after hook fails
before-hook-creation	Delete previous hook before launching new one

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Dependencies

# Update dependencies (downloads to charts/)
helm dependency update ./my-chart

# List dependencies
helm dependency list ./my-chart

# Build (rebuild Chart.lock)
helm dependency build ./my-chart

Conditional Dependencies in values.yaml

# values.yaml
postgresql:
  enabled: true
  auth:
    postgresPassword: "secret"
    database: "myapp"

redis:
  enabled: false

---

Chart Development

# Create a new chart scaffold
helm create my-chart

# Lint a chart for errors
helm lint ./my-chart

# Lint with specific values
helm lint ./my-chart -f values-prod.yaml

# Package a chart
helm package ./my-chart

# Package with specific version
helm package ./my-chart --version 2.0.0

# Push to OCI registry
helm push my-chart-2.0.0.tgz oci://registry.example.com/charts

# Template (render locally without install)
helm template my-release ./my-chart -f values.yaml --debug

# Run chart tests
helm test my-release

TIP

Always run helm lint and helm template before pushing chart changes. Catch YAML errors locally, not in production.

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OCI Registry Support

# Login to OCI registry
helm registry login registry.example.com

# Push chart to OCI
helm push my-chart-1.0.0.tgz oci://registry.example.com/charts

# Pull chart from OCI
helm pull oci://registry.example.com/charts/my-chart --version 1.0.0

# Install from OCI
helm install my-release oci://registry.example.com/charts/my-chart --version 1.0.0

---

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Test Yourself

1. What command installs a chart with a dry run to preview rendered templates?helm install my-release bitnami/nginx --dry-run --debug

2. How do you upgrade a release and automatically rollback if it fails?helm upgrade my-release bitnami/nginx --atomic

3. What command shows the user-supplied values of an installed release?helm get values my-release

4. How do you render templates locally without installing?helm template my-release ./my-chart -f values.yaml

5. What hook annotation runs a Job before resources are upgraded?"helm.sh/hook": pre-upgrade

6. How do you force a value to be treated as a string in --set?--set-string image.tag="1.25"

7. What does --reuse-values do during an upgrade? It merges new overrides with existing values. Without it, all values reset to chart defaults plus your overrides.

8. What command checks a chart for errors before deploying?helm lint ./my-chart

9. How do you keep release history after uninstalling?helm uninstall my-release --keep-history

10. What built-in object gives you the current release name in a template?.Release.Name

Common Gotchas

• --reuse-values silently keeps old values. If a chart adds new required values in an upgrade, --reuse-values will not include them. Review chart changelogs before upgrading.
• Forgetting helm lint before pushing. A YAML indentation error in templates will not show up until install time. Always lint and template-render locally first.
• Hook resources are not managed by the release. Hooks are created and deleted based on their delete policy. If a hook Job fails, it may linger and block future upgrades.
• helm upgrade without --install fails if the release does not exist. Use helm upgrade --install for idempotent CI/CD pipelines.

One-Liner Summary

Helm is the package manager for Kubernetes -- master install, upgrade --atomic, template, hooks, and values.yaml overrides to deploy and manage complex applications repeatably.

Last updated: 2026-03-20