helm create my-app

Standard chart structure:

my-app/

Ôö£ÔöÇÔöÇ Chart.yaml # Chart metadata

Ôö£ÔöÇÔöÇ values.yaml # Default configuration values

Ôö£ÔöÇÔöÇ charts/ # Chart dependencies

Ôö£ÔöÇÔöÇ templates/ # Kubernetes manifest templates

Ôöé Ôö£ÔöÇÔöÇ NOTES.txt # Post-install notes

Ôöé Ôö£ÔöÇÔöÇ _helpers.tpl # Template helpers

Ôöé Ôö£ÔöÇÔöÇ deployment.yaml

Ôöé Ôö£ÔöÇÔöÇ service.yaml

Ôöé Ôö£ÔöÇÔöÇ ingress.yaml

Ôöé Ôö£ÔöÇÔöÇ serviceaccount.yaml

Ôöé Ôö£ÔöÇÔöÇ hpa.yaml

Ôöé ÔööÔöÇÔöÇ tests/

Ôöé ÔööÔöÇÔöÇ test-connection.yaml

ÔööÔöÇÔöÇ .helmignore # Files to ignore

2. Configure Chart.yaml

Chart metadata defines the package:

apiVersion: v2

name: my-app

description: A Helm chart for My Application

type: application

version: 1.0.0 # Chart version

appVersion: "2.1.0" # Application version

Keywords for chart discovery

keywords:

- web

- api

- backend

Maintainer information

maintainers:

- name: DevOps Team

email: devops@example.com

url: https://github.com/example/my-app

Source code repository

sources:

- https://github.com/example/my-app

Homepage

home: https://example.com

Chart icon

icon: https://example.com/icon.png

Dependencies

dependencies:

- name: postgresql

version: "12.0.0"

repository: "https://charts.bitnami.com/bitnami"

condition: postgresql.enabled

- name: redis

version: "17.0.0"

repository: "https://charts.bitnami.com/bitnami"

condition: redis.enabled

3. Design values.yaml Structure

Organize values hierarchically:

Image configuration

image:

repository: myapp

tag: "1.0.0"

pullPolicy: IfNotPresent

Number of replicas

replicaCount: 3

Service configuration

service:

type: ClusterIP

port: 80

targetPort: 8080

Ingress configuration

ingress:

enabled: false

className: nginx

hosts:

- host: app.example.com

paths:

- path: /

pathType: Prefix

Resources

resources:

requests:

memory: "256Mi"

cpu: "250m"

limits:

memory: "512Mi"

cpu: "500m"

Autoscaling

autoscaling:

enabled: false

minReplicas: 2

maxReplicas: 10

targetCPUUtilizationPercentage: 80

Environment variables

env:

- name: LOG_LEVEL

value: "info"

ConfigMap data

configMap:

data:

APP_MODE: production

Dependencies

postgresql:

enabled: true

auth:

database: myapp

username: myapp

redis:

enabled: false

4. Create Template Files

Use Go templating with Helm functions:

templates/deployment.yaml:

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:

metadata:

labels:

{{- include "my-app.selectorLabels" . | nindent 8 }}

spec:

containers:

- name: {{ .Chart.Name }}

image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"

imagePullPolicy: {{ .Values.image.pullPolicy }}

ports:

- name: http

containerPort: {{ .Values.service.targetPort }}

resources:

{{- toYaml .Values.resources | nindent 12 }}

env:

{{- toYaml .Values.env | nindent 12 }}

5. Create Template Helpers

templates/_helpers.tpl:

{{/*

Expand the name of the chart.

*/}}

{{- define "my-app.name" -}}

{{- default .Chart.Name .Values.nameOverride | trunc 63 | trimSuffix "-" }}

{{- end }}

{{/*

Create a default fully qualified app name.

*/}}

{{- 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 }}

{{/*

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 }}

{{/*

Selector labels

*/}}

{{- define "my-app.selectorLabels" -}}

app.kubernetes.io/name: {{ include "my-app.name" . }}

app.kubernetes.io/instance: {{ .Release.Name }}

{{- end }}

6. Manage Dependencies

Add dependencies in Chart.yaml:

dependencies:

- name: postgresql

version: "12.0.0"

repository: "https://charts.bitnami.com/bitnami"

condition: postgresql.enabled

Update dependencies:

helm dependency update

helm dependency build

Override dependency values:

values.yaml

postgresql:

enabled: true

auth:

database: myapp

username: myapp

password: changeme

primary:

persistence:

enabled: true

size: 10Gi

7. Test and Validate

Validation commands:

Lint the chart

helm lint my-app/

Dry-run installation

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

Template rendering

helm template my-app ./my-app

Template with values

helm template my-app ./my-app -f values-prod.yaml

Show computed values

helm show values ./my-app

Validation script:

#!/bin/bash

set -e

echo "Linting chart..."

helm lint .

echo "Testing template rendering..."

helm template test-release . --dry-run

echo "Checking for required values..."

helm template test-release . --validate

echo "All validations passed!"

8. Package and Distribute

Package the chart:

helm package my-app/

Creates: my-app-1.0.0.tgz

Create chart repository:

Create index

helm repo index .

Upload to repository

AWS S3 example

aws s3 sync . s3://my-helm-charts/ --exclude "*" --include "*.tgz" --include "index.yaml"

Use the chart:

helm repo add my-repo https://charts.example.com

helm repo update

helm install my-app my-repo/my-app

9. Multi-Environment Configuration

Environment-specific values files:

my-app/

Ôö£ÔöÇÔöÇ values.yaml # Defaults

Ôö£ÔöÇÔöÇ values-dev.yaml # Development

Ôö£ÔöÇÔöÇ values-staging.yaml # Staging

ÔööÔöÇÔöÇ values-prod.yaml # Production

values-prod.yaml:

replicaCount: 5

image:

tag: "2.1.0"

resources:

requests:

memory: "512Mi"

cpu: "500m"

limits:

memory: "1Gi"

cpu: "1000m"

autoscaling:

enabled: true

minReplicas: 3

maxReplicas: 20

ingress:

enabled: true

hosts:

- host: app.example.com

paths:

- path: /

pathType: Prefix

postgresql:

enabled: true

primary:

persistence:

size: 100Gi

Install with environment:

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

10. Implement Hooks and Tests

Pre-install hook:

templates/pre-install-job.yaml

apiVersion: batch/v1

kind: Job

metadata:

name: {{ include "my-app.fullname" . }}-db-setup

annotations:

"helm.sh/hook": pre-install

"helm.sh/hook-weight": "-5"

"helm.sh/hook-delete-policy": hook-succeeded

spec:

template:

spec:

containers:

- name: db-setup

image: postgres:15

command: ["psql", "-c", "CREATE DATABASE myapp"]

restartPolicy: Never

Test connection:

templates/tests/test-connection.yaml

apiVersion: v1

kind: Pod

metadata:

name: "{{ include "my-app.fullname" . }}-test-connection"

annotations:

"helm.sh/hook": test

spec:

containers:

- name: wget

image: busybox

command: ['wget']

args: ['{{ include "my-app.fullname" . }}:{{ .Values.service.port }}']

restartPolicy: Never

Run tests:

helm test my-app

Common Patterns

Pattern 1: Conditional Resources

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

apiVersion: networking.k8s.io/v1

kind: Ingress

metadata:

name: {{ include "my-app.fullname" . }}

spec:

# ...

{{- end }}

Pattern 2: Iterating Over Lists

env:

{{- range .Values.env }}

• name: {{ .name }}

value: {{ .value | quote }}

{{- end }}

Pattern 3: Including Files

data:

config.yaml: |

{{- .Files.Get "config/application.yaml" | nindent 4 }}

Pattern 4: Global Values

global:

imageRegistry: docker.io

imagePullSecrets:

- name: regcred

Use in templates:

image: {{ .Values.global.imageRegistry }}/{{ .Values.image.repository }}

Best Practices

1. Use semantic versioning for chart and app versions

2. Document all values in values.yaml with comments

3. Use template helpers for repeated logic

4. Validate charts before packaging

5. Pin dependency versions explicitly

6. Use conditions for optional resources

7. Follow naming conventions (lowercase, hyphens)

8. Include NOTES.txt with usage instructions

9. Add labels consistently using helpers

10. Test installations in all environments

Troubleshooting

Template rendering errors:

helm template my-app ./my-app --debug

Dependency issues:

helm dependency update

helm dependency list

Installation failures:

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

kubectl get events --sort-by='.lastTimestamp'

Reference Files

Related Skills