Chart: Add resize policy.

[younsl]

What this PR does / why we need it:

This PR adds support for Kubernetes resizePolicy configuration to the ingress-nginx Helm chart. The resizePolicy feature allows containers to be resized without pod restarts, enabling dynamic resource adjustments for better resource utilization and cost efficiency.

The implementation adds resizePolicy support for:

• Controller pods (Deployment and DaemonSet)
• Admission webhook jobs (createSecret and patchWebhook)

Related Kubernetes Documentation

• https://kubernetes.io/docs/concepts/workloads/pods/resize-pod-resources/
• https://kubernetes.io/docs/reference/kubernetes-api/workload-resources/pod-v1/#Container

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

How Has This Been Tested?

• Added comprehensive unit tests for all resizePolicy configurations
• All tests pass successfully:

$ helm unittest .
### Chart [ ingress-nginx ] .

 PASS  Controller > ConfigMap > Add Headers     tests/controller-configmap-addheaders_test.yaml
 PASS  Controller > ConfigMap > Proxy Headers   tests/controller-configmap-proxyheaders_test.yaml
 PASS  Controller > ConfigMap   tests/controller-configmap_test.yaml
 PASS  Controller > DaemonSet   tests/controller-daemonset_test.yaml
 PASS  Controller > Deployment  tests/controller-deployment_test.yaml
 PASS  Controller > HPA tests/controller-hpa_test.yaml
 PASS  Controller > IngressClass > Aliases      tests/controller-ingressclass-aliases_test.yaml
 PASS  Controller > IngressClass        tests/controller-ingressclass_test.yaml
 PASS  Controller > KEDA        tests/controller-keda_test.yaml
 PASS  Controller > NetworkPolicy       tests/controller-networkpolicy_test.yaml
 PASS  Controller > PodDisruptionBudget tests/controller-poddisruptionbudget_test.yaml
 PASS  Controller > PrometheusRule      tests/controller-prometheusrule_test.yaml
 PASS  Controller > Service > Internal  tests/controller-service-internal_test.yaml
 PASS  Controller > Service > Metrics   tests/controller-service-metrics_test.yaml
 PASS  Controller > Service > Webhook   tests/controller-service-webhook_test.yaml
 PASS  Controller > Service     tests/controller-service_test.yaml
 PASS  Controller > ServiceAccount      tests/controller-serviceaccount_test.yaml
 PASS  Controller > ServiceMonitor      tests/controller-servicemonitor_test.yaml
 PASS  Default Backend > Deployment     tests/default-backend-deployment_test.yaml
 PASS  Default Backend > Extra ConfigMaps       tests/default-backend-extra-configmaps_test.yaml
 PASS  Default Backend > PodDisruptionBudget    tests/default-backend-poddisruptionbudget_test.yaml
 PASS  Default Backend > Service        tests/default-backend-service_test.yaml
 PASS  Default Backend > ServiceAccount tests/default-backend-serviceaccount_test.yaml

Charts:      1 passed, 1 total
Test Suites: 23 passed, 23 total
Tests:       138 passed, 138 total
Snapshot:    0 passed, 0 total
Time:        1.075678208s

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added unit and/or e2e tests to cover my changes.
• All new and existing tests passed.

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[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: younsl / name: Younsung Lee (5f489ec)

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @younsl. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[younsl]

This PR is similar to oauth2-proxy/manifests#346

[Gacko]

Since this feature is supported from v1.30 upwards only, I'd ask you to wrap it into a condition to check if the target cluster supports it or not.

[Gacko]

Please do not re-request my review without having changed anything. Thank you! 😄

[younsl]

@Gacko Thanks for the feedback! I've updated the implementation to include Kubernetes version checks for the resizePolicy feature.

[younsl]

@Gacko PTAL

[Gacko]

I went through your PR once again. In general I feel like you didn't dig into this project a lot and just want this field in the chart. While I appreciate your effort, I'd still ask you to get to know this project a bit better, because ultimately it's on the maintainers to further support your change in the future.

This feature is being introduced in v1.33 as a beta feature, which is enabled by default. Please update the capability checks accordingly.

Last but not least the admission webhook patch jobs are short-living, normally no longer than 5 seconds. I can barely imagine a resize to happen or make sense in this short time. So please either remove the property for the admission webhook patch job or elaborate on why you think we need this.

[Gacko]

/retitle Chart: Add resize policy.
/triage accepted
/kind feature
/priority backlog
/hold

[younsl]

@Gacko Thank you for the thorough review. I've addressed all your feedback:

• Updated capability check to v1.33 for beta feature
• Removed resizePolicy from admission webhook jobs (short-lived, <5s)
• Aligned capability checks with existing chart patterns
• Fixed indentation and updated documentation

[Gacko]

I left another round of things to change.

[younsl]

@Gacko PTAL. Apply your all suggestion

[younsl]

@Gacko Thank you so much for the thorough and constructive feedback. I really appreciate your patience and detailed guidance. I apologize for not being more familiar with the codebase initially - your review is helping me understand the project much better.

I'll carefully address all your comments and learn from this experience.

[Gacko]

/triage accepted
/kind feature
/priority backlog
/lgtm

I rebased your branch on top of main, just in case you wonder about the force push. Also I squashed your commits. Thank you very much for your endurance and efforts! 🙂

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Gacko, younsl

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[Gacko]

/unhold