Kubernetes GitOps: ArgoCD ile Surekli Dagitim

GitOps Nedir

Git repository'si tek gercek kaynak (single source of truth). Tum altyapi degisiklikleri Git commit olarak yapilir, ArgoCD otomatik uygular.

ArgoCD Kurulum

kubectl create namespace argocd
kubectl apply -n argocd 
  -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

# Arayuze erisim
kubectl port-forward svc/argocd-server -n argocd 8080:443

# Sifre al
kubectl -n argocd get secret argocd-initial-admin-secret 
  -o jsonpath='{.data.password}' | base64 -d

Uygulama Tanimlama

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: web-app
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/emrecihn/web-app
    targetRevision: main
    path: k8s/
  destination:
    server: https://kubernetes.default.svc
    namespace: uretim
  syncPolicy:
    automated:
      prune: true     # Silinen manifest'leri sil
      selfHeal: true  # Manuel degisiklikleri geri al
    syncOptions:
      - CreateNamespace=true

Rollout Stratejisi

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata:
  name: web-app
spec:
  replicas: 5
  strategy:
    canary:
      steps:
        - setWeight: 20   # %20 trafigi yeni versiyona
        - pause: {duration: 5m}
        - setWeight: 50
        - pause: {duration: 5m}
        - setWeight: 100

Image Updater

metadata:
  annotations:
    argocd-image-updater.argoproj.io/image-list: myapp=registry/myapp
    argocd-image-updater.argoproj.io/myapp.update-strategy: semver

GitOps ile altyapi degisiklikleri izlenebilir, geri alinabilir ve otomatik uygulanir hale gelir.