Installing charts in Kubernetes - Practice Exercises

Challenge - 5 Problems

💻 Command Output

intermediate

Output of Helm install command with missing chart

What is the output when you run helm install myapp missing-chart if the chart named missing-chart does not exist in any configured repository?

Kubernetes

helm install myapp missing-chart

A Release "myapp" has been installed successfully

B Warning: chart deprecated but installed anyway

C Error: chart "missing-chart" not found in helm repositories

D Error: failed to download "missing-chart" (hint: check your network)

💡 Hint

Think about what happens if Helm cannot find the chart locally or in any repo.

When Helm cannot find the specified chart in any configured repository, it returns an error indicating the chart is not found. It does not install anything.

❓ Configuration

intermediate

Correct Helm install command with custom values file

Which Helm install command correctly installs the chart nginx with a custom values file named custom-values.yaml?

A helm install nginx ./nginx --set-file custom-values.yaml

B helm install nginx ./nginx --values custom-values.yaml

C helm install nginx ./nginx -c custom-values.yaml

D helm install nginx ./nginx -f custom-values.yaml

💡 Hint

The flag for specifying a values file is either -f or --values.

The correct flag to specify a custom values file in Helm is --values or its short form -f. Option D uses the short form correctly.

🔀 Workflow

advanced

Order of steps to install a Helm chart from a new repository

What is the correct order of commands to add a new Helm repository named myrepo with URL https://example.com/charts and then install the chart mychart from it?

A 3,1,2,4

B 1,2,3,4

C 1,3,2,4

D 2,1,3,4

💡 Hint

You must add the repo, update local cache, then install the chart.

First, add the repo with helm repo add. Then update the repo cache with helm repo update. After that, install the chart using the repo name prefix. Finally, you can check pods with kubectl.

❓ Troubleshoot

advanced

Reason for Helm install failure with 'cannot re-use a name that is still in use' error

You run helm install myapp ./mychart but get the error cannot re-use a name that is still in use. What is the most likely cause?

A A release named 'myapp' already exists in the cluster

B The chart directory './mychart' is missing the Chart.yaml file

C The Kubernetes cluster is not reachable

D The Helm client version is incompatible with the server

💡 Hint

Think about what the error message says about the release name.

The error means a Helm release with the name 'myapp' already exists in the cluster. Helm does not allow installing a new release with the same name unless you upgrade or uninstall the existing one.

✅ Best Practice

expert

Best practice for installing Helm charts in production environments

Which practice is considered best for installing Helm charts in a production Kubernetes environment?

A Use a CI/CD pipeline to automate chart installation with reviewed and tested values files

B Manually run helm install commands on production nodes via SSH

C Install charts directly from public repositories without reviewing values

D Always use the --force flag to overwrite existing releases without checks

💡 Hint

Think about safety, repeatability, and automation in production.

Using a CI/CD pipeline to automate Helm chart installation with reviewed and tested values files ensures consistency, safety, and traceability in production deployments.

Practice

1. What is the primary purpose of using helm install in Kubernetes?

easy

A. To deploy an application packaged as a Helm chart

B. To delete a Kubernetes namespace

C. To update the Kubernetes cluster version

D. To create a new Kubernetes node

Solution

1. Step 1: Understand Helm's role

   Helm packages Kubernetes apps into charts for easy deployment.

2. Step 2: Purpose of helm install

   This command deploys the packaged app (chart) into the cluster.

3. Final Answer:

   To deploy an application packaged as a Helm chart -> Option A

4. Quick Check:

   Helm install = deploy app [OK]

Hint: Helm install means deploy app from chart [OK]

Common Mistakes:

• Confusing install with delete or update commands
• Thinking helm install creates nodes
• Assuming helm install manages cluster versions

2. Which of the following is the correct syntax to install a Helm chart named nginx with release name myweb?

easy

A. helm install nginx myweb

B. helm create myweb nginx

C. helm install myweb nginx

D. helm deploy myweb nginx

Solution

1. Step 1: Recall Helm install syntax

   The correct syntax is helm install [release-name] [chart-name].

2. Step 2: Match syntax to options

   helm install myweb nginx uses helm install myweb nginx, which matches the syntax.

3. Final Answer:

   helm install myweb nginx -> Option C

4. Quick Check:

   helm install release chart = helm install myweb nginx [OK]

Hint: Remember: helm install release-name chart-name [OK]

Common Mistakes:

• Swapping release name and chart name order
• Using helm create or helm deploy instead of install
• Omitting release name

3. What will be the output of the command helm install myapp bitnami/nginx --namespace web if the namespace web does not exist?

medium

A. Helm will prompt to create the namespace interactively

B. Helm will create the namespace web and install the chart

C. Helm will install the chart in the default namespace

D. Installation will fail with an error about missing namespace

Solution

1. Step 1: Understand namespace behavior

   Helm does not create namespaces automatically during install.

2. Step 2: Effect of missing namespace

   If the specified namespace web does not exist, Helm will error out.

3. Final Answer:

   Installation will fail with an error about missing namespace -> Option D

4. Quick Check:

   Missing namespace causes install error [OK]

Hint: Helm won't create namespaces automatically [OK]

Common Mistakes:

• Assuming Helm auto-creates namespaces
• Expecting install to default namespace silently
• Thinking Helm prompts for namespace creation

4. You run helm install myapp nginx --set replicaCount=3 but the app still runs with 1 replica. What is the likely cause?

medium

A. You must specify the namespace with --namespace

B. The chart does not support the replicaCount parameter

C. The --set flag syntax is incorrect

D. The Helm client version is outdated

Solution

1. Step 1: Check parameter support

   Not all charts support all parameters; replicaCount must be defined in the chart's values.

2. Step 2: Effect of unsupported parameter

   If unsupported, setting replicaCount has no effect, so default 1 replica remains.

3. Final Answer:

   The chart does not support the replicaCount parameter -> Option B

4. Quick Check:

   Unsupported param means no effect [OK]

Hint: Check if chart supports your --set keys [OK]

Common Mistakes:

• Assuming all charts accept replicaCount
• Thinking namespace affects replica count
• Believing --set syntax is always wrong
• Blaming Helm version without checking chart

5. You want to install a Helm chart myapp with a custom image tag v2.0 and in namespace production. Which command correctly does this in one step?

hard

A. helm install myapp ./myapp-chart --set image.tag=v2.0 --namespace production

B. helm install ./myapp-chart myapp --set image.tag=v2.0 --namespace production

C. helm install myapp ./myapp-chart --image.tag=v2.0 --namespace production

D. helm install myapp ./myapp-chart --set image=v2.0 --namespace production

Solution

1. Step 1: Confirm Helm install syntax

   The syntax is helm install [release-name] [chart-path] [flags].

2. Step 2: Correct use of --set and namespace

   Use --set image.tag=v2.0 to override image tag and --namespace production to specify namespace.

3. Final Answer:

   helm install myapp ./myapp-chart --set image.tag=v2.0 --namespace production -> Option A

4. Quick Check:

   Release, chart, --set key=value, --namespace [OK]

Hint: Use --set key=value and --namespace together [OK]

Common Mistakes:

• Swapping release name and chart path
• Using --image.tag instead of --set
• Setting wrong key like image=v2.0
• Omitting namespace flag