`helm create mychart`	Create new chart
`helm package mychart`	Package chart
`helm lint mychart`	Lint chart
`helm template mychart`	Render templates
`helm dependency update`	Update dependencies
`helm show values repo/chart`	Show default values
`helm show chart repo/chart`	Show chart info

Release Management

`helm install myrelease repo/chart`	Install chart
`helm install myrelease . -f values.yaml`	Install with custom values
`helm install myrelease . --set key=value`	Install with set values
`helm install myrelease . --dry-run`	Dry run install
`helm upgrade myrelease repo/chart`	Upgrade release
`helm upgrade --install myrelease repo/chart`	Install or upgrade
`helm rollback myrelease 1`	Rollback to revision
`helm uninstall myrelease`	Uninstall release

Information

`helm list`	List releases
`helm list -A`	List all namespaces
`helm status myrelease`	Show release status
`helm history myrelease`	Show release history
`helm get values myrelease`	Get release values
`helm get manifest myrelease`	Get release manifest

Repository

`helm repo add name url`	Add repository
`helm repo list`	List repositories
`helm repo update`	Update repositories
`helm repo remove name`	Remove repository
`helm search repo keyword`	Search in repos
`helm search hub keyword`	Search Artifact Hub

Chart Structure

Directory Structure

Chart layout

mychart/
├── Chart.yaml          # Chart metadata
├── values.yaml         # Default values
├── charts/             # Dependencies
├── templates/          # Kubernetes manifests
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── _helpers.tpl    # Template helpers
│   ├── NOTES.txt       # Post-install notes
│   └── tests/
└── .helmignore

Chart.yaml

Chart metadata

apiVersion: v2
name: mychart
version: 1.0.0
appVersion: "1.16.0"
description: My application chart
type: application
keywords:
  - web
  - app
maintainers:
  - name: John Doe
    email: john@example.com
dependencies:
  - name: postgresql
    version: "12.x.x"
    repository: "https://charts.bitnami.com/bitnami"
    condition: postgresql.enabled

values.yaml

Default values

replicaCount: 1

image:
  repository: nginx
  tag: "1.21"
  pullPolicy: IfNotPresent

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: false
  hosts:
    - host: chart.local
      paths:
        - path: /

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

nodeSelector: {}
tolerations: []
affinity: {}

Templates

Template Syntax

Values access

{{ .Values.replicaCount }}
{{ .Values.image.repository }}

Built-in objects

{{ .Release.Name }}
{{ .Release.Namespace }}
{{ .Chart.Name }}
{{ .Chart.Version }}
{{ .Capabilities.KubeVersion }}

Conditionals

{{- if .Values.ingress.enabled }}
# ingress config
{{- end }}

{{- if not .Values.autoscaling.enabled }}
replicas: {{ .Values.replicaCount }}
{{- end }}

Loops

{{- range .Values.ingress.hosts }}
- host: {{ .host }}
{{- end }}

{{- range $key, $value := .Values.env }}
- name: {{ $key }}
  value: {{ $value | quote }}
{{- end }}

With scope

{{- with .Values.nodeSelector }}
nodeSelector:
  {{- toYaml . | nindent 2 }}
{{- end }}

Template Functions

String functions

{{ .Values.name | quote }}
{{ .Values.name | upper }}
{{ .Values.name | lower }}
{{ .Values.name | title }}
{{ .Values.name | trim }}
{{ .Values.name | default "default" }}

Include template

{{ include "mychart.fullname" . }}
{{- include "mychart.labels" . | nindent 4 }}

Required value

{{ required "A valid name is required!" .Values.name }}

ToYaml

resources:
  {{- toYaml .Values.resources | nindent 2 }}

Indent

{{ .Values.config | indent 4 }}
{{ .Values.config | nindent 4 }}

_helpers.tpl

Define helpers

{{/*
Create a default fully qualified app name.
*/}}
{{- define "mychart.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- printf "%s-%s" .Release.Name .Chart.Name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}

{{/*
Common labels
*/}}
{{- define "mychart.labels" -}}
helm.sh/chart: {{ .Chart.Name }}-{{ .Chart.Version }}
app.kubernetes.io/name: {{ include "mychart.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end }}