QA: Next Steps in Kubernetes – From Basics to Practice

[fdavid]

After learning the core concepts of Kubernetes, it’s time to dive deeper into the essentials that every beginner should master. This guide explains the next building blocks step by step.

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1. Basic kubectl Commands

kubectl is the command-line tool used to interact with a Kubernetes cluster. Here are the most common commands:

• Check cluster resources

  kubectl get nodes
  kubectl get pods
  kubectl get services
  

• Get detailed info

  kubectl describe pod <pod-name>
  

• Apply configuration

  kubectl apply -f my-app.yaml
  

• Delete resources

  kubectl delete pod <pod-name>
  kubectl delete -f my-app.yaml
  

These commands help you inspect, create, and manage resources in your cluster.

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2. Writing Simple Deployment and Service YAMLs

Kubernetes resources are usually defined in YAML files.

• Deployment Example

  apiVersion: apps/v1
  kind: Deployment
  metadata:
    name: my-app
  spec:
    replicas: 3
    selector:
      matchLabels:
        app: my-app
    template:
      metadata:
        labels:
          app: my-app
      spec:
        containers:
        - name: my-app
          image: nginx
          ports:
          - containerPort: 80
  

• Service Example

  apiVersion: v1
  kind: Service
  metadata:
    name: my-app-service
  spec:
    type: LoadBalancer
    selector:
      app: my-app
    ports:
      - port: 80
        targetPort: 80
  

The Deployment ensures your app runs with 3 replicas, while the Service exposes it so others can access it.

For a deeper dive into YAML files and manifests, take a look here.

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3. Scaling Your Application

Scaling means changing the number of running pods.

• Manual scaling:

  kubectl scale deployment my-app --replicas=5
  

• Automatic scaling (Horizontal Pod Autoscaler – HPA):

  kubectl autoscale deployment my-app --min=2 --max=10 --cpu-percent=80
  

Kubernetes can adjust capacity automatically, so your app is always available and cost-efficient.

For more information regarding scaling, take a look here.

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4. Monitoring and Logging Basics

To keep your apps healthy, you need visibility.

• Logs (view what your app is doing):

  kubectl logs <pod-name>
  

• Monitoring tools:

  • Metrics Server (basic CPU/memory usage)
  • Prometheus + Grafana (advanced monitoring & dashboards)

• Health checks: Use liveness and readiness probes in your YAML to let Kubernetes know if your app is running correctly.

Example probe in a pod definition:

livenessProbe:
  httpGet:
    path: /
    port: 80
  initialDelaySeconds: 5
  periodSeconds: 10

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5. Putting It All Together

• Write YAML files for your Deployment and Service.
• Use kubectl apply to create them.
• Scale manually or automatically.
• Check logs and monitor performance.