How do I deploy containerized applications with Kubernetes?

Deploying a containerized application with Kubernetes usually means: package your app in a container image, define the desired state in YAML, and apply it to a Kubernetes cluster.

Typical workflow

1. Containerize the app

Create a container image with a Dockerfile, then build and push it to a registry.

docker build -t myrepo/myapp:1.0 .
docker push myrepo/myapp:1.0

---

2. Create Kubernetes manifests

You generally need at least:

• Deployment: runs and manages your app pods
• Service: exposes your app inside or outside the cluster
• Optional: Ingress, ConfigMap, Secret, PersistentVolumeClaim

---

3. Define a Deployment

Example deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myrepo/myapp:1.0
          ports:
            - containerPort: 8080

This tells Kubernetes to keep 3 replicas of your app running.

---

4. Expose it with a Service

Example service.yaml:

apiVersion: v1
kind: Service
metadata:
  name: myapp-service
spec:
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 8080
  type: ClusterIP

If you want external access, use:

• LoadBalancer on cloud providers
• NodePort for basic external exposure
• Ingress for host/path-based routing

---

5. Apply the manifests

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

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6. Verify deployment

kubectl get pods
kubectl get deployments
kubectl get svc

Check logs if something fails:

kubectl logs <pod-name>
kubectl describe pod <pod-name>

---

Common extras

Environment variables

env:
  - name: NODE_ENV
    value: production

Health checks

livenessProbe:
  httpGet:
    path: /health
    port: 8080
readinessProbe:
  httpGet:
    path: /ready
    port: 8080

Scaling

kubectl scale deployment myapp --replicas=5

Updating

Build and push a new image tag, then update the Deployment:

kubectl set image deployment/myapp myapp=myrepo/myapp:1.1

---

Minimal example in one file

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myrepo/myapp:1.0
          ports:
            - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: myapp
spec:
  selector:
    app: myapp
  ports:
    - port: 80
      targetPort: 8080
  type: ClusterIP

Apply it with:

kubectl apply -f app.yaml

If you want, I can also give you:

1. a full step-by-step deployment example,
2. a Helm chart example, or
3. a deployment guide for a specific app stack like Node.js, Python, or Java.