charts: add ability to specify topologySpreadConstraints

[irasnyd]

Summary

This PR adds the ability to specify a topologySpreadConstraints for the headlamp deployment.

An example was included which prefers to schedule multiple Pods in different Availability Zones, and requires that multiple Pods are on different Nodes. When uncommented, the example has no effect on the default configuration with replicaCount: 1.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: irasnyd / name: Ira W. Snyder (ed63f80)

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: irasnyd
Once this PR has been reviewed and has the lgtm label, please assign joaquimrocha for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

Welcome @irasnyd!

It looks like this is your first PR to kubernetes-sigs/headlamp 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/headlamp has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[Copilot]

Pull request overview

This PR adds support for configuring topologySpreadConstraints in the Headlamp Helm chart deployment, enabling users to control how pods are distributed across topology domains (zones, nodes, etc.) for improved high availability.

Key Changes:

• Added topologySpreadConstraints field to values.yaml with a comprehensive example showing zone and node spread configuration
• Implemented template logic in deployment.yaml to render the constraints with automatic labelSelector injection when not explicitly provided

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
charts/headlamp/values.yaml	Added topologySpreadConstraints configuration field with commented example demonstrating multi-zone and multi-node pod spreading
charts/headlamp/templates/deployment.yaml	Implemented template logic to render topologySpreadConstraints with automatic labelSelector injection for constraints that don't specify one

The implementation is well-designed and follows established patterns in the chart. The template correctly handles YAML formatting using a combination of toYaml, nindent, and trim to produce valid output, and includes intelligent labelSelector auto-injection for improved usability. The example configuration demonstrates best practices for pod topology spreading with both soft (zone) and hard (node) constraints.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[illume]

Thanks!

Can you please add something to the charts/README.md?

[ashu8912]

Hii @irasnyd thanks for the PR, i have continued the docs addition here in #4559