fix(operator): preserve metadata in partial conversion responses

[julienmancuso]

Summary

Fixes #12351.

Kubernetes Server-Side Apply can send partial objects through the CRD conversion webhook while reconciling fields owned under another API version. The v1beta1 JSON normalizer removed the empty top-level metadata: {} object, causing the API server to reject the conversion response with:

returned invalid metadata: missing metadata in converted object

This change:

• restores the top-level metadata envelope after normalizing Kubernetes runtime.Object values;
• preserves the removal of nested encoder artifacts such as podTemplate.metadata: {};
• adds marshal regression coverage for all v1beta1 root resource types; and
• adds conversion-webhook regression coverage for partial DGD, DCD, and DGDR objects.

Validation

go test ./api/... -count=1

All Operator API tests pass.

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Summary by CodeRabbit

• Bug Fixes

  • Preserved the top-level metadata field as an empty object when converting Kubernetes objects with minimal metadata.
  • Ensured conversion webhook responses retain valid runtime-object structure for partial objects.

• Tests

  • Added coverage for metadata preservation across supported API versions and object kinds.
  • Added validation for successful webhook conversions and returned object counts.

[coderabbitai]

Walkthrough

Changes

Metadata preservation

Layer / File(s)	Summary
Runtime-object metadata normalization deploy/operator/api/v1beta1/marshal.go, deploy/operator/api/v1beta1/marshal_test.go	The normalizer restores missing or nil root metadata for runtime objects, with tests covering multiple typed objects.
Partial-object webhook validation deploy/operator/api/conversion_webhook_test.go	The webhook test verifies successful conversion of minimal objects for multiple kinds while retaining empty metadata.

Estimated code review effort: 3 (Moderate) | ~20 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title is concise and accurately captures the main change: preserving metadata in partial conversion responses.
Description check	✅ Passed	The description covers the bug, fix, linked issue, and validation; it only misses the exact template headings and reviewer-start note.
Linked Issues check	✅ Passed	The changes address #12351 by restoring top-level metadata on partial converted objects and adding regression tests for the reported failure.
Out of Scope Changes check	✅ Passed	The added normalization logic and tests are directly tied to the metadata-preservation fix, with no clear unrelated scope creep.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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[coderabbitai]

🧹 Nitpick comments (1)

deploy/operator/api/conversion_webhook_test.go (1)

25-107: 📐 Maintainability & Code Quality | 🔵 Trivial | 💤 Low value

Add t.Log headings for each test step.

• deploy/operator/api/conversion_webhook_test.go#L25-L107: add headings before scheme setup, request construction/execution, and response validation.
• deploy/operator/api/v1beta1/marshal_test.go#L52-L115: add headings before marshaling and metadata assertions in each subtest.

As per coding guidelines, “Use t.Log to tell each Go test's story, with one heading before every block implementing a test step.”

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@deploy/operator/api/conversion_webhook_test.go` around lines 25 - 107, The
tests lack step headings describing their execution flow. In
deploy/operator/api/conversion_webhook_test.go:25-107, add t.Log headings before
scheme setup, request construction and execution, and response validation; in
deploy/operator/api/v1beta1/marshal_test.go:52-115, add t.Log headings before
marshaling and metadata assertions in each subtest, using one heading for each
test-step block.

Source: Coding guidelines

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@deploy/operator/api/conversion_webhook_test.go`:
- Around line 25-107: The tests lack step headings describing their execution
flow. In deploy/operator/api/conversion_webhook_test.go:25-107, add t.Log
headings before scheme setup, request construction and execution, and response
validation; in deploy/operator/api/v1beta1/marshal_test.go:52-115, add t.Log
headings before marshaling and metadata assertions in each subtest, using one
heading for each test-step block.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: b6ae6db3-0399-4c2d-ad97-92d86f640c23

📥 Commits

Reviewing files that changed from the base of the PR and between a387b06 and 3a1b28f.

📒 Files selected for processing (3)

• deploy/operator/api/conversion_webhook_test.go
• deploy/operator/api/v1beta1/marshal.go
• deploy/operator/api/v1beta1/marshal_test.go

[devin-ai-integration]

Devin Review found 1 potential issue.