Rolling update strategy in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the rolling update strategy type in a Kubernetes deployment.

Kubernetes

strategy:
  type: [1]

Drag options to blanks, or click blank then click option'

ARecreate

BRollingUpdate

CBlueGreen

DCanary

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Recreate' which stops all old pods before starting new ones.

Using 'BlueGreen' or 'Canary' which are not native Kubernetes strategy types.

The RollingUpdate strategy allows Kubernetes to update pods gradually without downtime.

2fill in blank

medium

Complete the code to set the maximum number of pods that can be unavailable during a rolling update.

Kubernetes

strategy:
  rollingUpdate:
    maxUnavailable: [1]

Drag options to blanks, or click blank then click option'

A50%

B0

C25%

D100%

Attempts:

3 left

💡 Hint

Common Mistakes

Setting maxUnavailable to 0 which means no downtime allowed.

Setting maxUnavailable to 100% which would stop all pods.

Setting maxUnavailable to 25% means up to 25% of pods can be down during the update.

3fill in blank

hard

Fix the error in the rolling update configuration by completing the missing field.

Kubernetes

strategy:
  rollingUpdate:
    maxSurge: [1]

Drag options to blanks, or click blank then click option'

A2

Btwo

C200%

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using a word like 'two' instead of a number.

Using negative numbers which are invalid.

Using percentages over 100% which is not allowed.

The maxSurge field must be a positive integer or percentage. '2' is valid.

4fill in blank

hard

Fill both blanks to configure a rolling update with 1 max surge and 0 max unavailable pods.

Kubernetes

strategy:
  rollingUpdate:
    maxSurge: [1]
    maxUnavailable: [2]

Drag options to blanks, or click blank then click option'

A1

B0

C25%

D50%

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping maxSurge and maxUnavailable values.

Using percentages when integers are expected.

This configuration allows 1 extra pod during update and no pods unavailable.

5fill in blank

hard

Fill all three blanks to create a deployment spec with rolling update strategy, max surge 2, and max unavailable 25%.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: example-deployment
spec:
  replicas: 3
  strategy:
    type: [1]
    rollingUpdate:
      maxSurge: [2]
      maxUnavailable: [3]

Drag options to blanks, or click blank then click option'

ARollingUpdate

B2

C25%

DRecreate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Recreate' instead of 'RollingUpdate' for strategy type.

Mixing up maxSurge and maxUnavailable values.

This deployment uses the rolling update strategy with 2 extra pods allowed and 25% pods can be unavailable during update.

Practice

1. What is the main purpose of a rolling update in Kubernetes?

easy

A. To update an application without downtime by gradually replacing pods

B. To delete all pods and recreate them at once

C. To backup the current state of the application

D. To scale the application to zero replicas

Solution

1. Step 1: Understand rolling update concept

   A rolling update replaces pods one by one to avoid downtime.

2. Step 2: Compare options with concept

   Only To update an application without downtime by gradually replacing pods describes gradual replacement without downtime.

3. Final Answer:

   To update an application without downtime by gradually replacing pods -> Option A

4. Quick Check:

   Rolling update = gradual pod replacement [OK]

Hint: Rolling update means update pods one by one without downtime [OK]

Common Mistakes:

• Thinking rolling update deletes all pods at once
• Confusing rolling update with backup
• Assuming rolling update scales pods to zero

2. Which kubectl command starts a rolling update by changing the image of a deployment?

easy

A. kubectl set image deployment/myapp myapp-container=myimage:v2

B. kubectl rollout undo deployment/myapp

C. kubectl scale deployment/myapp --replicas=0

D. kubectl get pods --watch

Solution

1. Step 1: Identify command to update image

   The command to update a deployment's image is 'kubectl set image'.

2. Step 2: Match command with options

   kubectl set image deployment/myapp myapp-container=myimage:v2 uses 'kubectl set image' correctly to start rolling update.

3. Final Answer:

   kubectl set image deployment/myapp myapp-container=myimage:v2 -> Option A

4. Quick Check:

   Change image = kubectl set image [OK]

Hint: Use kubectl set image to start rolling update [OK]

Common Mistakes:

• Using rollout undo to start update
• Scaling replicas to zero instead of updating image
• Using get pods to update image

3. After running kubectl set image deployment/myapp myapp-container=myimage:v2, what does kubectl rollout status deployment/myapp show?

medium

A. The configuration details of the deployment

B. The current rollout progress of the deployment update

C. The logs of the deployment pods

D. The list of pods in the deployment

Solution

1. Step 1: Understand purpose of rollout status

   The command 'kubectl rollout status' shows progress of deployment updates.

2. Step 2: Compare options with command purpose

   The current rollout progress of the deployment update correctly describes rollout progress; others describe different commands.

3. Final Answer:

   The current rollout progress of the deployment update -> Option B

4. Quick Check:

   Rollout status = update progress [OK]

Hint: Rollout status shows update progress, not pod list or logs [OK]

Common Mistakes:

• Confusing rollout status with pod listing
• Expecting logs from rollout status
• Thinking rollout status shows config details

4. You ran kubectl set image deployment/myapp myapp-container=myimage:v2 but the new pods crash. Which command helps you revert to the previous version?

medium

A. kubectl scale deployment/myapp --replicas=0

B. kubectl delete deployment myapp

C. kubectl rollout undo deployment/myapp

D. kubectl get pods --all-namespaces

Solution

1. Step 1: Identify command to revert deployment

   'kubectl rollout undo' reverts deployment to previous version.

2. Step 2: Match command with options

   kubectl rollout undo deployment/myapp correctly reverts the deployment; others do not revert updates.

3. Final Answer:

   kubectl rollout undo deployment/myapp -> Option C

4. Quick Check:

   Undo rollout = kubectl rollout undo [OK]

Hint: Use rollout undo to revert bad updates quickly [OK]

Common Mistakes:

• Deleting deployment instead of undoing
• Scaling replicas to zero instead of reverting
• Using get pods which only lists pods

5. You want to update your deployment with zero downtime and ensure at least 2 pods are always available during the update. Which rolling update settings in the deployment spec help achieve this?

hard

A. Set 'maxUnavailable' to 1 and 'maxSurge' to 1 in 'rollingUpdate' strategy

B. Set 'maxUnavailable' to 2 and 'maxSurge' to 0 in 'rollingUpdate' strategy

C. Set 'maxUnavailable' to 3 and 'maxSurge' to 3 in 'rollingUpdate' strategy

D. Set 'maxUnavailable' to 0 and 'maxSurge' to 2 in 'rollingUpdate' strategy

Solution

1. Step 1: Understand maxUnavailable and maxSurge

   'maxUnavailable' controls how many pods can be down; 'maxSurge' controls extra pods created during update.

2. Step 2: Ensure at least 2 pods always available

   Setting 'maxUnavailable' to 0 means no pods go down; 'maxSurge' 2 allows 2 extra pods to be created for smooth update.

3. Final Answer:

   Set 'maxUnavailable' to 0 and 'maxSurge' to 2 in 'rollingUpdate' strategy -> Option D

4. Quick Check:

   Zero unavailable + surge 2 = no downtime, 2 pods always up [OK]

Hint: maxUnavailable 0 means no pod down; maxSurge adds extra pods [OK]

Common Mistakes:

• Setting maxUnavailable > 0 causes downtime
• Setting maxSurge to 0 prevents extra pods during update
• Choosing high maxUnavailable and maxSurge causing instability