Tutorial

Deploy Your First Application¶

Type: Tutorial (Learning-oriented)

Time: ~30 minutes | Level: Beginner

Prerequisites: First Deployment tutorial

In this tutorial, you’ll deploy a simple web application to your KUP6S cluster using ArgoCD. You’ll learn the GitOps workflow and how to expose your app via Traefik ingress.

What you’ll deploy¶

A simple “Hello KUP6S” web application that demonstrates:

ArgoCD Application manifest
Kubernetes Deployment and Service
Traefik Ingress with Let’s Encrypt SSL
Health checks and readiness probes

Step 1: Verify cluster access¶

Ensure you can access your cluster:

export KUBECONFIG=~/kup6s/kube-hetzner/kup6s_kubeconfig.yaml
kubectl get nodes

All nodes should show Ready status.

Step 2: Access ArgoCD UI¶

Get ArgoCD admin password¶

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

Access ArgoCD¶

Open your browser to https://argocd.ops.kup6s.net

Note

If you haven’t configured DNS yet, add to your /etc/hosts:

YOUR_LOAD_BALANCER_IP  argocd.ops.kup6s.net

Get your LB IP: kubectl get svc -n kube-system traefik -o jsonpath='{.status.loadBalancer.ingress[0].ip}'

Username: admin
Password: (from command above)

Step 3: Create application namespace¶

kubectl create namespace hello-kup6s

Verify:

kubectl get namespace hello-kup6s

Step 4: Create application manifests¶

Create deployment manifest¶

Save as hello-deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-kup6s
  namespace: hello-kup6s
  labels:
    app: hello-kup6s
spec:
  replicas: 2
  selector:
    matchLabels:
      app: hello-kup6s
  template:
    metadata:
      labels:
        app: hello-kup6s
    spec:
      containers:
      - name: hello
        image: nginx:1.27-alpine
        ports:
        - containerPort: 80
          name: http
        resources:
          requests:
            cpu: 50m
            memory: 64Mi
          limits:
            cpu: 100m
            memory: 128Mi
        livenessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 10
          periodSeconds: 10
        readinessProbe:
          httpGet:
            path: /
            port: 80
          initialDelaySeconds: 5
          periodSeconds: 5
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html
      volumes:
      - name: html
        configMap:
          name: hello-html
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: hello-html
  namespace: hello-kup6s
data:
  index.html: |
    <!DOCTYPE html>
    <html>
    <head>
        <title>Hello KUP6S</title>
        <style>
            body {
                font-family: Arial, sans-serif;
                display: flex;
                justify-content: center;
                align-items: center;
                height: 100vh;
                margin: 0;
                background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
                color: white;
            }
            .container {
                text-align: center;
            }
            h1 {
                font-size: 4em;
                margin: 0;
            }
            p {
                font-size: 1.5em;
            }
        </style>
    </head>
    <body>
        <div class="container">
            <h1>🚀 Hello KUP6S!</h1>
            <p>Your first app is running on Kubernetes</p>
            <p>Pod: <strong id="hostname"></strong></p>
        </div>
        <script>
            fetch('/hostname')
                .then(r => r.text())
                .then(h => document.getElementById('hostname').textContent = h)
                .catch(() => document.getElementById('hostname').textContent = window.location.hostname);
        </script>
    </body>
    </html>

Create service manifest¶

Save as hello-service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: hello-kup6s
  namespace: hello-kup6s
  labels:
    app: hello-kup6s
spec:
  type: ClusterIP
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: http
  selector:
    app: hello-kup6s

Create ingress manifest¶

Save as hello-ingress.yaml:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: hello-kup6s
  namespace: hello-kup6s
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
    traefik.ingress.kubernetes.io/router.tls: "true"
spec:
  ingressClassName: traefik
  tls:
  - hosts:
    - hello.sites.kup6s.com
    secretName: hello-kup6s-tls
  rules:
  - host: hello.sites.kup6s.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: hello-kup6s
            port:
              number: 80

Step 5: Deploy the application¶

Apply manifests¶

kubectl apply -f hello-deployment.yaml
kubectl apply -f hello-service.yaml
kubectl apply -f hello-ingress.yaml

Watch the deployment¶

kubectl get pods -n hello-kup6s -w

Wait until both pods show Running and 2/2 ready.

Press Ctrl+C to stop watching.

Step 6: Verify the deployment¶

Check pods¶

kubectl get pods -n hello-kup6s

Expected output:

NAME                            READY   STATUS    RESTARTS   AGE
hello-kup6s-xxxxxxxxxx-xxxxx    1/1     Running   0          1m
hello-kup6s-xxxxxxxxxx-xxxxx    1/1     Running   0          1m

Check service¶

kubectl get svc -n hello-kup6s

Check ingress¶

kubectl get ingress -n hello-kup6s

You should see an IP address assigned.

Check certificate¶

kubectl get certificate -n hello-kup6s

Wait until READY shows True (may take 1-2 minutes for Let’s Encrypt).

Step 7: Access your application¶

Configure DNS¶

Point hello.sites.kup6s.com to your load balancer IP.

Or for testing, add to /etc/hosts:

YOUR_LOAD_BALANCER_IP  hello.sites.kup6s.com

Open in browser¶

Visit: https://hello.sites.kup6s.com

You should see your “Hello KUP6S!” page with a valid SSL certificate! 🎉

Step 8: Create ArgoCD Application (GitOps way)¶

Now let’s manage this app the GitOps way with ArgoCD.

Create Git repository¶

mkdir hello-kup6s-gitops
cd hello-kup6s-gitops
git init

Commit manifests¶

cp ../hello-*.yaml .
git add .
git commit -m "Initial hello-kup6s application"

Push to Git server¶

# Push to your Git server (GitHub, GitLab, etc.)
git remote add origin git@your-git-server:your-org/hello-kup6s.git
git push -u origin main

Create ArgoCD Application¶

Save as argocd-app.yaml:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: hello-kup6s
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://your-git-server/your-org/hello-kup6s.git
    targetRevision: main
    path: .
  destination:
    server: https://kubernetes.default.svc
    namespace: hello-kup6s
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
    - CreateNamespace=true

Apply it:

kubectl apply -f argocd-app.yaml

Watch ArgoCD sync¶

Go to ArgoCD UI and you’ll see your application syncing automatically!

Step 9: Test GitOps workflow¶

Make a change¶

Edit hello-deployment.yaml and change replicas:

spec:
  replicas: 3  # Changed from 2

Commit and push¶

git add hello-deployment.yaml
git commit -m "Scale to 3 replicas"
git push

Watch ArgoCD¶

Within 3 minutes, ArgoCD will detect the change and automatically sync!

Check pods:

kubectl get pods -n hello-kup6s

You should now see 3 pods running! 🚀

Congratulations! 🎉¶

You’ve successfully deployed your first application using GitOps!

What you’ve learned¶

How to create Kubernetes Deployments, Services, and Ingress
How to configure Traefik ingress with Let’s Encrypt SSL
How to use ArgoCD for GitOps deployments
How the automated sync and self-heal features work

What’s next?¶

Monitoring basics - Learn to monitor your app with Grafana and Loki
Create S3 bucket - Add object storage to your app
Query logs - Find and analyze application logs

Troubleshooting¶

Pods stuck in Pending¶

kubectl describe pod -n hello-kup6s <pod-name>

Check for resource constraints or storage issues.

Certificate not ready¶

kubectl describe certificate -n hello-kup6s hello-kup6s-tls
kubectl logs -n cert-manager -l app=cert-manager

Ingress not accessible¶

# Check Traefik logs
kubectl logs -n kube-system -l app.kubernetes.io/name=traefik

# Verify ingress
kubectl get ingress -n hello-kup6s -o yaml

ArgoCD not syncing¶

Check the repository URL is correct
Verify ArgoCD has access to your Git repository
Check ArgoCD application status: kubectl get application -n argocd hello-kup6s -o yaml