Kubernetes Helm Charts: Uygulama Paketleme ve Dağıtım

Helm Nedir?

Helm, Kubernetes için paket yöneticisidir. Charts adı verilen paketler ile karmaşık uygulamaları kolayca deploy edebilirsiniz.

Helm Kurulumu

# macOS
brew install helm

# Linux
curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash

# Versiyon kontrolü
helm version

Temel Komutlar

# Repo ekleme
helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update

# Chart arama
helm search repo nginx

# Chart kurulumu
helm install my-nginx bitnami/nginx

# Release listesi
helm list

# Upgrade
helm upgrade my-nginx bitnami/nginx --set replicaCount=3

# Rollback
helm rollback my-nginx 1

# Uninstall
helm uninstall my-nginx

Custom Chart Oluşturma

# Yeni chart oluştur
helm create myapp

# Dizin yapısı
myapp/
├── Chart.yaml          # Chart metadata
├── values.yaml         # Default değerler
├── charts/             # Bağımlı chartlar
├── templates/          # Kubernetes manifests
│   ├── deployment.yaml
│   ├── service.yaml
│   ├── ingress.yaml
│   ├── _helpers.tpl    # Template helpers
│   └── NOTES.txt       # Post-install notlar
└── .helmignore

Chart.yaml

apiVersion: v2
name: myapp
description: A Laravel application Helm chart
type: application
version: 0.1.0
appVersion: "1.0.0"

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

values.yaml

replicaCount: 2

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

service:
  type: ClusterIP
  port: 80

ingress:
  enabled: true
  className: nginx
  hosts:
    - host: myapp.example.com
      paths:
        - path: /
          pathType: Prefix

resources:
  limits:
    cpu: 500m
    memory: 512Mi
  requests:
    cpu: 100m
    memory: 128Mi

env:
  APP_ENV: production
  APP_DEBUG: "false"

postgresql:
  enabled: true
  auth:
    database: myapp
    username: myapp

redis:
  enabled: true

Template Örneği

# templates/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: {{ include "myapp.fullname" . }}
  labels:
    {{- include "myapp.labels" . | nindent 4 }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      {{- include "myapp.selectorLabels" . | nindent 6 }}
  template:
    metadata:
      labels:
        {{- include "myapp.selectorLabels" . | nindent 8 }}
    spec:
      containers:
        - name: {{ .Chart.Name }}
          image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
          ports:
            - containerPort: {{ .Values.service.port }}
          env:
            {{- range $key, $value := .Values.env }}
            - name: {{ $key }}
              value: {{ $value | quote }}
            {{- end }}
          resources:
            {{- toYaml .Values.resources | nindent 12 }}

Chart Test ve Deploy

# Template render test
helm template myapp ./myapp

# Dry-run
helm install myapp ./myapp --dry-run --debug

# Değerlerle kurulum
helm install myapp ./myapp \
  --set image.tag=v1.2.3 \
  --set replicaCount=3 \
  -f production-values.yaml

Sonuç

Helm, Kubernetes deployment'larını yönetilebilir ve tekrarlanabilir hale getirir. Kendi chart'larınızı oluşturarak DevOps süreçlerinizi hızlandırın.