Upgrading and rolling back releases in Kubernetes - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to upgrade a Helm release named 'myapp' with the chart located in './chart'.

Kubernetes

helm upgrade myapp [1]

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

Arelease

Bmychart

C./chart

Dupgrade

Attempts:

3 left

💡 Hint

Common Mistakes

Using the release name again instead of the chart path.

Using 'upgrade' as the chart argument.

Using an unrelated word like 'release'.

The helm upgrade command requires the release name followed by the path to the chart directory or chart name. Here, './chart' specifies the local chart directory.

2fill in blank

medium

Complete the command to rollback the Helm release 'myapp' to revision 2.

Kubernetes

helm rollback myapp [1]

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

A2

Bcurrent

Clatest

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'latest' or 'current' instead of a revision number.

Using the wrong revision number.

The helm rollback command requires the release name and the revision number to rollback to. Here, revision 2 is specified.

3fill in blank

hard

Fix the error in the command to upgrade 'myapp' with the chart './chart' and set the image tag to 'v2'.

Kubernetes

helm upgrade myapp [1] --set image.tag=v2

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

Amyapp

B./chart

Cchart

Dv2

Attempts:

3 left

💡 Hint

Common Mistakes

Using the release name instead of the chart path.

Trying to fill a value for the image tag blank that doesn't exist.

The helm upgrade command requires the release name followed by the path to the chart directory or chart name. Here, './chart' specifies the local chart directory and --set image.tag=v2 overrides the tag.

4fill in blank

hard

Fill both blanks to upgrade 'myapp' with the chart './chart' and set the replica count to 3.

Kubernetes

helm upgrade myapp [1] --set [2]=3

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

A./chart

BreplicaCount

Creplicas

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'replicas' or 'count' instead of 'replicaCount'.

Using an incorrect chart path.

The first blank is the chart path './chart'. The second blank is the correct Helm value key 'replicaCount' to set the number of replicas.

5fill in blank

hard

Fill all three blanks to rollback 'myapp' to revision 1 and verify the status.

Kubernetes

helm rollback [1] [2] && helm status [3]

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

Amyapp

B1

Cmyapp-release

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different release name in the status command.

Using 'myapp-release' instead of 'myapp'.

Using 'status' as a release name.

The rollback command needs the release name 'myapp' and the revision number '1'. The status command should check the same release 'myapp'.

Practice

1. What is the primary purpose of the helm upgrade command in Kubernetes?

easy

A. To create a new Helm release from scratch

B. To delete a Helm release from the cluster

C. To update an existing Helm release with a new version of the application

D. To list all Helm releases in the cluster

Solution

1. Step 1: Understand the role of helm upgrade

   This command is used to update an existing release with new chart or configuration changes.

2. Step 2: Differentiate from other Helm commands

   Unlike helm install which creates new releases, helm upgrade modifies existing ones.

3. Final Answer:

   To update an existing Helm release with a new version of the application -> Option C

4. Quick Check:

   Upgrade means update existing release [OK]

Hint: Upgrade means update existing release, not create or delete [OK]

Common Mistakes:

• Confusing upgrade with install
• Thinking upgrade deletes releases
• Assuming upgrade lists releases

2. Which of the following is the correct syntax to rollback a Helm release named myapp to revision 2?

easy

A. helm upgrade myapp --revision=2

B. helm rollback myapp 2

C. helm rollback --release myapp --rev 2

D. helm revert myapp 2

Solution

1. Step 1: Recall Helm rollback syntax

   The correct command is helm rollback RELEASE_NAME REVISION.

2. Step 2: Match syntax with options

   helm rollback myapp 2 matches the correct syntax exactly: helm rollback myapp 2.

3. Final Answer:

   helm rollback myapp 2 -> Option B

4. Quick Check:

   Rollback syntax is helm rollback name revision [OK]

Hint: Rollback uses: helm rollback release_name revision_number [OK]

Common Mistakes:

• Using helm upgrade instead of rollback
• Using incorrect flags like --revision
• Using nonexistent command 'helm revert'

3. Given the following commands executed in order:

helm install myapp ./chart
helm upgrade myapp ./chart --set image.tag=v2
helm rollback myapp 1
helm status myapp

What will be the image tag shown in the status output after the rollback?

medium

A. No image tag shown

B. v2 (tag set during upgrade)

C. v3 (latest tag automatically applied)

D. v1 (original tag from install)

Solution

1. Step 1: Understand the sequence of commands

   First, the app is installed with default image tag (assumed v1). Then upgraded to tag v2. Then rolled back to revision 1 (the original install).

2. Step 2: Determine image tag after rollback

   Rollback to revision 1 restores the original state, so image tag reverts to v1.

3. Final Answer:

   v1 (original tag from install) -> Option D

4. Quick Check:

   Rollback restores previous revision state [OK]

Hint: Rollback returns to previous revision state, undoing upgrades [OK]

Common Mistakes:

• Assuming rollback keeps upgraded tag
• Thinking rollback applies latest tag automatically
• Ignoring rollback effect on release state

4. You ran helm upgrade myapp ./chart --set replicas=3 but the number of pods did not change. What is the most likely cause?

medium

A. The chart does not use the replicas value to set pod count

B. You forgot to run helm rollback first

C. The helm upgrade command syntax is incorrect

D. The Kubernetes cluster is down

Solution

1. Step 1: Check if the chart supports the replicas value

   Not all charts use the replicas parameter; if the chart template ignores it, no change occurs.

2. Step 2: Rule out other causes

   Syntax is correct, rollback is unrelated, and cluster down would cause more errors.

3. Final Answer:

   The chart does not use the replicas value to set pod count -> Option A

4. Quick Check:

   Chart must support value for upgrade to affect it [OK]

Hint: Check if chart templates use your set values before expecting changes [OK]

Common Mistakes:

• Assuming all charts respond to replicas value
• Confusing rollback with upgrade necessity
• Blaming syntax when command is correct

5. You want to upgrade your Helm release webapp to version 3 of your chart but keep the previous configuration values intact except for changing the image tag to v3. Which command achieves this safely?

hard

A. helm upgrade webapp ./chart --reuse-values --set image.tag=v3

B. helm upgrade webapp ./chart --reset-values --set image.tag=v3

C. helm upgrade webapp ./chart --set image.tag=v3

D. helm rollback webapp 3 --set image.tag=v3

Solution

1. Step 1: Understand --reuse-values option

   This option keeps existing values from the previous release and applies new overrides.

2. Step 2: Compare with other options

   --reset-values resets to chart defaults, losing previous config. Omitting reuse-values loses previous config. Rollback does not upgrade.

3. Final Answer:

   helm upgrade webapp ./chart --reuse-values --set image.tag=v3 -> Option A

4. Quick Check:

   Use --reuse-values to keep old config and override selectively [OK]

Hint: Use --reuse-values with --set to keep config and update specific values [OK]

Common Mistakes:

• Using --reset-values and losing config
• Not using --reuse-values and losing previous settings
• Trying rollback to upgrade