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

apiVersion: v2
name: my-app
description: A Helm chart for My Application
version: 1.0.0
appVersion: "2.1.0"

dependencies:
  - name: postgresql
    version: "12.0.0"
    repository: "https://charts.bitnami.com/bitnami"
    condition: postgresql.enabled

image:
  repository: myapp
  tag: "1.0.0"
  pullPolicy: IfNotPresent

replicaCount: 3

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: false
  hosts:
    - host: app.example.com
      paths:
        - path: /
          pathType: Prefix

resources:
  requests:
    memory: "256Mi"
    cpu: "250m"
  limits:
    memory: "512Mi"
    cpu: "500m"

autoscaling:
  enabled: false
  minReplicas: 2
  maxReplicas: 10

{{- define "my-app.fullname" -}}
{{- if .Values.fullnameOverride }}
{{- .Values.fullnameOverride | trunc 63 | trimSuffix "-" }}
{{- else }}
{{- printf "%s-%s" .Release.Name .Chart.Name | trunc 63 | trimSuffix "-" }}
{{- end }}
{{- end }}

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

apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "my-app.fullname" . }}
  labels:
    {{- include "my-app.labels" . | nindent 4 }}
spec:
  {{- if not .Values.autoscaling.enabled }}
  replicas: {{ .Values.replicaCount }}
  {{- end }}
  selector:
    matchLabels:
      {{- include "my-app.selectorLabels" . | nindent 6 }}
  template:
    spec:
      containers:
      - name: {{ .Chart.Name }}
        image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
        resources:
          {{- toYaml .Values.resources | nindent 12 }}

my-app/
├── values.yaml          # Defaults
├── values-dev.yaml      # Development
├── values-staging.yaml  # Staging
└── values-prod.yaml     # Production

helm install my-app ./my-app -f values-prod.yaml -n production

{{- if .Values.ingress.enabled }}
apiVersion: networking.k8s.io/v1
kind: Ingress
...
{{- end }}

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

helm lint my-app/
helm template my-app ./my-app --dry-run
helm install my-app ./my-app --dry-run --debug