Kubernetes vs Postman Comparison Guide for Beginners

kubectl get nodes                      # cluster machines
kubectl get pods                       # running containers
kubectl describe pod <pod-name>        # details and events
kubectl logs <pod-name>                # container logs
kubectl get svc                        # services and ports

Postman - first request
1. New > HTTP Request
2. Method: GET
3. URL: https://httpbin.org/get
4. Click Send
5. Check: status 200, response time, JSON body
6. Save it into a collection named 'Practice'

apiVersion: apps/v1
kind: Deployment
metadata:
  name: api
spec:
  replicas: 2
  selector:
    matchLabels: { app: api }
  template:
    metadata:
      labels: { app: api }
    spec:
      containers:
        - name: api
          image: nginx:1.27
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: api
spec:
  selector: { app: api }
  ports:
    - port: 80
      targetPort: 80

minikube start
kubectl apply -f api.yaml
kubectl get pods -l app=api
kubectl scale deployment api --replicas=3
kubectl port-forward svc/api 8080:80
# open http://localhost:8080 in your browser

// Tests tab in Postman
pm.test("status is 200", function () {
    pm.response.to.have.status(200);
});

pm.test("response time under 800 ms", function () {
    pm.expect(pm.response.responseTime).to.be.below(800);
});

pm.test("body has an id", function () {
    const body = pm.response.json();
    pm.expect(body).to.have.property("id");
});

npm install -g newman
newman run practice.postman_collection.json \
  -e staging.postman_environment.json \
  --reporters cli,junit \
  --reporter-junit-export results.xml

# .github/workflows/deploy-and-test.yml (simplified)
name: deploy-and-test
on: [push]
jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Deploy to staging cluster
        run: kubectl apply -f k8s/
        # cluster credentials come from repository secrets
      - name: Wait for rollout
        run: kubectl rollout status deployment/api --timeout=120s
      - name: API tests with Newman
        run: |
          npm install -g newman
          newman run tests/api.postman_collection.json -e tests/staging.json

# If API tests fail, roll back the deployment
kubectl rollout undo deployment/api
kubectl rollout status deployment/api
# Then investigate logs:
kubectl logs deployment/api --tail=100

Testing / QA path:
  HTTP basics -> Postman -> test scripts -> Newman in CI -> Docker basics
DevOps path:
  Linux -> Docker -> Kubernetes basics -> CI/CD -> Postman/Newman for checks
Both paths meet at the pipeline.