Helm Intermediate Questions

How to use these interview questions

🧠 Read each question carefully.

Try answering it yourself before expanding the answer to compare with the ideal response.

Level: Intermediate

🟡 Practical Applications & Troubleshooting.

Focus on real-world scenarios, debugging, optimization, and deeper configuration.

Expand all answers

1. What is the Go template language?

It is the templating engine used by Helm.

Files in the templates/ directory utilize Go text/template syntax (e.g., {{ .Values.key }}) to inject values into YAML manifests dynamically.

2. Explain the use of _helpers.tpl file.

It stores reusable template snippets or 'named templates'.

You define common logic (like chart labels or name generation) here once and include them in multiple resource templates using include or template actions.

3. How do you perform a dry-run of an installation?

Use helm install ... --dry-run.

This simulates the installation, sending the chart to the cluster to validate manifests against the API server, but doesn't actually persist resources.

4. What acts as the scope (or context) in a Helm template?

The dot (.).

Initially, . refers to the root object containing Values, Release, Chart, etc. Inside a range or with block, the scope of . changes.

5. How do you debug a template that is failing to render?

Use helm template --debug.

The --debug flag prints generated manifests even if they are invalid YAML, along with error messages to help identify the faulty line.

6. what is a Helm Hook?

A mechanism to run tasks at specific points in a release lifecycle.

Examples: pre-install (e.g., enable db migration), post-install (e.g., slack notification), or pre-delete. They are typically defined as Job resources with an annotation.

7. How do you specify dependencies for a chart?

In the Chart.yaml file under the dependencies list.

You specify the chart name, repository URL, and version range. You then run helm dependency update to download them.

8. What is the difference between helm upgrade --install and standard install?

Idempotency.

helm upgrade --install works even if the release doesn't exist (it installs it). If it does exist, it upgrades it. This is preferred in CI/CD pipelines.

9. How do you remove a null or empty value from the output?

Using the default function or if blocks.

Example: {{ .Values.image.tag | default "latest" }} ensures a value is present. {{ if .Values.ingress.enabled }} prevents rendering empty objects.

10. What is the purpose of .helmignore?

It specifies files to exclude from the chart package.

Similar to .gitignore, it prevents unnecessary files (like test scripts, local configs) from being included in the final .tgz archive.

11. How do you access built-in objects like Release Name?

Via the Release object.

Example: {{ .Release.Name }} gives the name of the release. {{ .Release.Namespace }} gives the namespace.

12. What command retrieves the values used for a specifically deployed release?

helm get values [release-name].

This shows the user-supplied values (overrides). Use --all to see computed values including defaults.

13. Can you manage CRDs (Custom Resource Definitions) with Helm?

Yes, by placing them in the crds/ folder.

However, Helm only installs them; it does not upgrade or delete them to prevent accidental data loss.

14. How do you create a package (tarball) of your chart?

helm package [chart-directory].

This validates the chart and creates a chart-name-version.tgz file ready for distribution.

15. What is the function toYaml used for?

It converts a structured object (like a map in Values) into YAML format.

Essential for passing whole blocks of configuration (like resources: or securityContext:) directly into the manifest.

16. How do you install a plugin in Helm?

helm plugin install [url].

Plugins extend Helm's core functionality (e.g., helm-diff, helm-s3).

17. What is the purpose of the required function?

To force chart validation failure if a value is missing.

Example: {{ required "A valid database password is required!" .Values.db.password }} stops installation if the value isn't provided.

18. How do you loop through a list in a template?

Using the range action.

Example:

{{- range .Values.ingress.hosts }}
- {{ . }}
{{- end }}

??? question "19. Explain the atomic flag in upgrade. helm upgrade --atomic**.

It treats the upgrade as an atomic operation. If the upgrade fails, it automatically rolls back changes. It also implies `--wait`.

20. How do you use the lookup function?

To query the cluster for existing resources at template render time.

Example: Check if a Secret exists before attempting to create it, or reuse an existing password. Note: lookup checks are not performed during dry-runs.

---

📬 DevopsPilot Weekly — Learn DevOps, Cloud & Gen AI the simple way.
👉 Subscribe here