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Back to lesson: Choose the Right Workload Controller

Free lab · CKA Prep Program · Module 3: Workloads and scheduling

Rollout and scale

30 min hands-on · Core

Browser Kubernetes (Killercoda 1-node) or Play-with-Kubernetes; no local installs.

Two ways to do this lab: in your browser on Killercoda (free, no install), or on Play-with-Kubernetes as a free practice field. The Killercoda button opens in a new tab; this study page stays here. Killercoda runs one free scenario at a time: if you see a waiting queue, close other Killercoda tabs and wait a minute.

Objectives

  • Deploy, scale and expose a workload imperatively
  • Run a rolling update and watch it converge
  • Roll back a bad rollout from history
  1. Step 1

    Deploy and expose

    Create a deployment (`kubectl create deployment web --image=nginx:1.25`), scale it to 3, expose it ClusterIP. Verify with `kubectl get deploy,rs,pods,svc -o wide`.

  2. Step 2

    Rolling update

    Change the image with `kubectl set image`, then watch `kubectl rollout status`. Record how many pods stay available during the roll; that number is the point of the exercise.

  3. Step 3

    Break it, roll it back

    Set a nonexistent image tag, confirm the rollout stalls, then `kubectl rollout undo`. Verify the old ReplicaSet serves again.

How to confirm it worked

  • Deployment at 3 replicas behind a ClusterIP Service
  • Rollout status observed converging, availability number recorded
  • Bad rollout stalled on record, rollback verified serving