GitOps with ArgoCD

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Goal

Install ArgoCD on kind and point it at a Git repository so the cluster state is declared in Git and automatically reconciled.

Prerequisites

• StatefulSet and PVC
• A GitHub/GitLab repository with your Helm chart pushed

What is GitOps

GitOps means:

The desired cluster state is declared in a Git repository. An operator (ArgoCD) continuously compares the live cluster to the repo and auto-fixes drift.

No one runs kubectl apply manually in production — the cluster pulls its config from Git.

Install ArgoCD

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

kubectl -n argocd wait --for=condition=Ready pods --all --timeout=120s

Access the ArgoCD UI

# Port-forward the API server
kubectl -n argocd port-forward svc/argocd-server 8080:443 &

# Get the initial admin password
kubectl -n argocd get secret argocd-initial-admin-secret \
  -o jsonpath="{.data.password}" | base64 -d

Open https://localhost:8080 in a browser, login as admin with the password above.

Install the ArgoCD CLI

brew install argocd

argocd login localhost:8080 --insecure --username admin

Register a cluster

ArgoCD needs access to your cluster:

argocd cluster add kind-kind

Create an Application

Create argocd-app.yaml:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: web-app
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/your-org/web-chart-repo
    path: web-chart
    targetRevision: HEAD
  destination:
    server: https://kubernetes.default.svc
    namespace: default
  syncPolicy:
    automated:
      prune: true
      selfHeal: true

Apply:

kubectl apply -f argocd-app.yaml

ArgoCD clones the repo, templates the Helm chart, and applies it to the cluster. The UI shows the app as Synced.

Drift detection

Delete a pod manually:

kubectl delete pod -l app=web-demo
# ArgoCD sees the drift and recreates it within seconds

Change an image tag in the Git repo, commit, and push. ArgoCD detects the change and syncs automatically.

Checkpoint

argocd app list
# NAME     CLUSTER          NAMESPACE  STATUS  HEALTH
# web-app  https://...      default    Synced  Healthy

argocd app get web-app
# Shows resources, sync status, health

Next: Prometheus and Grafana — cluster monitoring and dashboards.