feat: add prefix and suffix options to replacements for targeting con...

[Br1an67]

Fixes #4080

Summary

Add prefix and suffix options to the FieldOptions type for replacements. This enables targeting specific elements in string arrays (like container args) that match a prefix and/or suffix pattern. The matched prefix and suffix are preserved in the resulting value.

This addresses the issue where replacements couldn't reliably target --key=value style container arguments without relying on array index ordering.

Changes

• Added Prefix and Suffix string fields to FieldOptions in api/types/replacement.go
• Updated setFieldValue function in api/filters/replacement/replacement.go to handle prefix/suffix matching for both scalar and sequence (array) nodes
• Added setFieldValueInSequence helper function to iterate over array elements and replace values that match the prefix/suffix pattern
• Added matchesPrefixAndSuffix helper function for prefix/suffix validation
• Added comprehensive test cases covering:
  • Prefix option on scalar fields
  • Prefix option on sequence fields (container args)
  • Prefix option with multiple matches in a sequence
  • Suffix option on scalar fields
  • Combined prefix and suffix options
  • No-match scenarios (prefix doesn't match)

Usage Example

replacements:
- source:
    kind: Namespace
    name: my-namespace
    fieldPath: metadata.name
  targets:
  - select:
      kind: Deployment
    fieldPaths:
    - spec.template.spec.containers.[name=cert-manager].args
    options:
      prefix: "--leader-election-namespace="

This replaces any arg starting with --leader-election-namespace= (e.g., --leader-election-namespace=kube-system) with --leader-election-namespace=my-namespace.

Testing

All existing tests pass, plus new test cases for the prefix/suffix functionality.

 api/filters/replacement/replacement.go      |  64 +++++++
 api/filters/replacement/replacement_test.go | 283 ++++++++++++++++++++++++++++
 api/types/replacement.go                    |  14 +-
 4 files changed, 360 insertions(+), 2 deletions(-)

[linux-foundation-easycla]

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• ✅ login: Br1an67 / name: Br1an (9624549)

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[k8s-ci-robot]

Hi @Br1an67. Thanks for your PR.

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[koba1t]

Please pass the CLA.

[k8s-ci-robot]

PR needs rebase.

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