feat(pruner): add default resource limits to controller and webhook

[infernus01]

Summary

Adds default resource requests and limits for tekton-pruner-controller and tekton-pruner-webhook deployments in the operator.

Changes

Modified pkg/reconciler/kubernetes/tektonpruner/transform.go to include a new addDefaultResourceLimits() transformer that injects default
resource specifications:

tekton-pruner-controller

resources:
  requests:
    cpu: 100m
    memory: 256Mi
  limits:
    cpu: 500m
    memory: 2Gi

tekton-pruner-webhook

  resources:
    requests:
      cpu: 50m
      memory: 64Mi
    limits:
      cpu: 250m
      memory: 128Mi

Rationale

Benchmark data: Testing showed the pruner controller uses 846-1126 MB heap memory when tracking 26k-38k resident PipelineRuns in its informer cache.

Override Mechanism

These defaults can be overridden via TektonConfig or TektonPruner CR:

  apiVersion: operator.tekton.dev/v1alpha1
  kind: TektonConfig
  spec:
    pruner:
      options:
        deployments:
        - name: tekton-pruner-controller
          spec:
            template:
              spec:
                containers:
                - name: controller
                  resources:
                    limits:
                      memory: 4Gi  # Override default

The transformer runs before the options transformer, so user-specified values take precedence.

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Run make test lint before submitting a PR
• Includes tests (if functionality changed/added)
• Includes docs (if user facing)
• Commit messages follow commit message best practices

See the contribution guide for more details.

Release Notes

Operator now applies default resource limits to tekton-pruner-controller (2Gi memory) and tekton-pruner-webhook (512Mi memory) based on benchmark data. CPU limits omitted to avoid throttling. Override via TektonConfig.spec.tektonpruner.options.deployments if needed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 27.75%. Comparing base (408ade4) to head (5c94388).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4066      +/-   ##
==========================================
- Coverage   27.79%   27.75%   -0.04%     
==========================================
  Files         477      478       +1     
  Lines       25691    25727      +36     
==========================================
  Hits         7140     7140              
- Misses      17822    17858      +36     
  Partials      729      729              

Flag	Coverage Δ
unit-tests	27.75% <ø> (-0.04%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[pratap0007]

/lgtm

[jkhelil]

@infernus01 Please addd release note

[pratap0007]

/lgtm

[tekton-robot]

New changes are detected. LGTM label has been removed.

[jkhelil]

/approve

[jkhelil]

please Move injection into common.AddDefaultResourceRequirements(map[string]ResourceRequirements) and keep values in pruner defaults.go

[jkhelil]

/approve cancel

[tekton-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
To complete the pull request process, please ask for approval from pratap0007 after the PR has been reviewed.

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