deckhouse / deckhouse/deckhouse

[kube-dns] With mutating webhook from kube-dns, one cannot achieve 'Guaranteed' QoS for statefulset Pods

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priority/backlog source/internal-client type/bug type/good-first-issue
Dominant language
Go
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Forks
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Avg merge
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Merged PRs (30d)
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Description

Preflight Checklist
  • I agree to follow the Code of Conduct that this project adheres to.
  • I have searched the issue tracker for an issue that matches the one I want to file, without success.
Version

V1.44

Expected Behavior

Following the QoS doc, user should be able to achieve Guaranteed QoS.

Actual Behavior

QoS can be only 'Burstable' because mutating webhook from kube-dns adds init container with empty resources.

Steps To Reproduce

No response

Additional Information

The injected container
https://github.com/deckhouse/deckhouse/blob/main/modules/042-kube-dns/images/sts-pods-hosts-appender-webhook/main.go#L99-L119

Logs

No response

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start in modules/042-kube-dns/images/sts-pods-hosts-appender-webhook/main.go, especially lines 99-119 where the init container is injected. Read the Kubernetes Guaranteed QoS requirements, then reproduce with a StatefulSet and verify that the injected container's resources no longer make the Pod Burstable.

Written by the indexing model from the issue text.

Assessment

Tech stack
go, kubernetes
Domain
infrastructure
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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