Chart Structure

my-app/
├── Chart.yaml              # Chart metadata (required)
├── Chart.lock              # Dependency lock file (generated)
├── values.yaml             # Default configuration values (required)
├── values.schema.json      # JSON schema for values validation
├── .helmignore             # Patterns to ignore when packaging
├── README.md               # Chart documentation
├── LICENSE                 # Chart license
├── charts/                 # Chart dependencies (bundled)
│   └── postgresql-12.0.0.tgz
├── crds/                   # Custom Resource Definitions
│   └── my-crd.yaml
├── templates/              # Kubernetes manifest templates (required)
│   ├── NOTES.txt          # Post-install instructions
│   ├── _helpers.tpl       # Template helper functions
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── configmap.yaml
│   ├── secret.yaml
│   ├── serviceaccount.yaml
│   ├── hpa.yaml
│   ├── pdb.yaml
│   ├── networkpolicy.yaml
│   └── tests/
│       └── test-connection.yaml
└── files/                  # Additional files to include
    └── config/
        └── app.conf

apiVersion: v2 # Required: API version
name: my-application # Required: Chart name
version: 1.2.3 # Required: Chart version (SemVer)
appVersion: "2.5.0" # Application version
description: A Helm chart for my application # Required
type: application # Chart type: application or library
keywords: # Search keywords
  - web
  - api
  - backend
home: https://example.com # Project home page
sources: # Source code URLs
  - https://github.com/example/my-app
maintainers: # Maintainer list
  - name: John Doe
    email: john@example.com
    url: https://github.com/johndoe
icon: https://example.com/icon.png # Chart icon URL
kubeVersion: ">=1.24.0" # Compatible Kubernetes versions
deprecated: false # Mark chart as deprecated
annotations: # Arbitrary annotations
  example.com/release-notes: https://example.com/releases/v1.2.3
dependencies: # Chart dependencies
  - name: postgresql
    version: "12.0.0"
    repository: "https://charts.bitnami.com/bitnami"
    condition: postgresql.enabled
    tags:
      - database
    import-values:
      - child: database
        parent: database
    alias: db

type: application

type: library

# Global values (shared with subcharts)
global:
  imageRegistry: docker.io
  imagePullSecrets: []

# Image configuration
image:
  registry: docker.io
  repository: myapp/web
  tag: "" # Defaults to .Chart.AppVersion
  pullPolicy: IfNotPresent

# Deployment settings
replicaCount: 1
revisionHistoryLimit: 10

# Pod configuration
podAnnotations: {}
podSecurityContext:
  runAsNonRoot: true
  runAsUser: 1000
  fsGroup: 1000

# Container security
securityContext:
  allowPrivilegeEscalation: false
  readOnlyRootFilesystem: true
  capabilities:
    drop:
      - ALL

# Service
service:
  type: ClusterIP
  port: 80
  targetPort: http
  annotations: {}

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

# Autoscaling
autoscaling:
  enabled: false
  minReplicas: 1
  maxReplicas: 100
  targetCPUUtilizationPercentage: 80

# Node selection
nodeSelector: {}
tolerations: []
affinity: {}

# Monitoring
serviceMonitor:
  enabled: false
  interval: 30s

{
  "$schema": "https://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "replicaCount": {
      "type": "integer",
      "minimum": 1
    },
    "image": {
      "type": "object",
      "required": ["repository"],
      "properties": {
        "repository": {
          "type": "string"
        },
        "tag": {
          "type": "string"
        },
        "pullPolicy": {
          "type": "string",
          "enum": ["Always", "IfNotPresent", "Never"]
        }
      }
    }
  },
  "required": ["image"]
}

{{/*
Standard naming helpers
*/}}
{{- define "my-app.name" -}}
{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" -}}
{{- end -}}

{{- define "my-app.fullname" -}}
{{- if .Values.fullnameOverride -}}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" -}}
{{- else -}}
{{- $name := default .Chart.Name .Values.nameOverride -}}
{{- if contains $name .Release.Name -}}
{{- .Release.Name | trunc 63 | trimSuffix "-" -}}
{{- else -}}
{{- printf "%s-%s" .Release.Name $name | trunc 63 | trimSuffix "-" -}}
{{- end -}}
{{- end -}}
{{- end -}}

{{- define "my-app.chart" -}}
{{- printf "%s-%s" .Chart.Name .Chart.Version | replace "+" "_" | trunc 63 | trimSuffix "-" -}}
{{- end -}}

{{/*
Common labels
*/}}
{{- define "my-app.labels" -}}
helm.sh/chart: {{ include "my-app.chart" . }}
{{ include "my-app.selectorLabels" . }}
{{- if .Chart.AppVersion }}
app.kubernetes.io/version: {{ .Chart.AppVersion | quote }}
{{- end }}
app.kubernetes.io/managed-by: {{ .Release.Service }}
{{- end -}}

{{- define "my-app.selectorLabels" -}}
app.kubernetes.io/name: {{ include "my-app.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
{{- end -}}

{{/*
Image name helper
*/}}
{{- define "my-app.image" -}}
{{- $registry := .Values.global.imageRegistry | default .Values.image.registry -}}
{{- $repository := .Values.image.repository -}}
{{- $tag := .Values.image.tag | default .Chart.AppVersion -}}
{{- printf "%s/%s:%s" $registry $repository $tag -}}
{{- end -}}

Thank you for installing {{ .Chart.Name }}.

Your release is named {{ .Release.Name }}.

To learn more about the release, try:

  $ helm status {{ .Release.Name }}
  $ helm get all {{ .Release.Name }}

{{- if .Values.ingress.enabled }}

Application URL:
{{- range .Values.ingress.hosts }}
  http{{ if $.Values.ingress.tls }}s{{ end }}://{{ .host }}{{ .path }}
{{- end }}
{{- else }}

Get the application URL by running:
  export POD_NAME=$(kubectl get pods --namespace {{ .Release.Namespace }} -l "app.kubernetes.io/name={{ include "my-app.name" . }}" -o jsonpath="{.items[0].metadata.name}")
  kubectl port-forward $POD_NAME 8080:80
  echo "Visit http://127.0.0.1:8080"
{{- end }}

# Chart.yaml
dependencies:
  - name: postgresql
    version: "12.0.0"
    repository: "https://charts.bitnami.com/bitnami"
    condition: postgresql.enabled # Enable/disable via values
    tags: # Group dependencies
      - database
    import-values: # Import values from subchart
      - child: database
        parent: database
    alias: db # Reference as .Values.db

# Update dependencies
helm dependency update

# List dependencies
helm dependency list

# Build dependencies
helm dependency build

dependencies:
  - name: postgresql
    repository: https://charts.bitnami.com/bitnami
    version: 12.0.0
digest: sha256:abcd1234...
generated: "2024-01-01T00:00:00Z"

# Development files
.git/
.gitignore
*.md
docs/

# Build artifacts
*.swp
*.bak
*.tmp
*.orig

# CI/CD
.travis.yml
.gitlab-ci.yml
Jenkinsfile

# Testing
test/
*.test

# IDE
.vscode/
.idea/
*.iml

crds/
├── my-app-crd.yaml
└── another-crd.yaml

version: 2.3.1 # Chart version
appVersion: "1.5.0" # Application version

# templates/tests/test-connection.yaml
apiVersion: v1
kind: Pod
metadata:
  name: "{{ include "my-app.fullname" . }}-test-connection"
  annotations:
    "helm.sh/hook": test
    "helm.sh/hook-delete-policy": before-hook-creation,hook-succeeded
spec:
  containers:
  - name: wget
    image: busybox
    command: ['wget']
    args: ['{{ include "my-app.fullname" . }}:{{ .Values.service.port }}']
  restartPolicy: Never

helm test my-release
helm test my-release --logs

apiVersion: batch/v1
kind: Job
metadata:
  name: {{ include "my-app.fullname" . }}-migration
  annotations:
    "helm.sh/hook": pre-upgrade,pre-install
    "helm.sh/hook-weight": "-5"
    "helm.sh/hook-delete-policy": before-hook-creation,hook-succeeded

helm-charts/
├── index.yaml
├── my-app-1.0.0.tgz
├── my-app-1.1.0.tgz
├── my-app-1.2.0.tgz
└── another-chart-2.0.0.tgz

helm repo index . --url https://charts.example.com