Add `MergeMode` for toggling highlighting of merge conflicts by LucaBernstein · Pull Request #218 · gardener/gardener-landscape-kit

LucaBernstein · 2026-04-01T14:34:10Z

How to categorize this PR?

/area usability
/kind enhancement

What this PR does / why we need it:
Currently, once a components.yaml file is present, its versions will not be updated anymore by resolve plain. This PR makes the glk update non-overridden versions.

Also, the "default-value"-handling that until now was only applied to the components.yaml, has been extended to all manifests by integrating it into WriteObjectsToFilesystem / ThreeWayMergeManifest.

Which issue(s) this PR fixes:
Fixes #210
Follow-up to #216

Special notes for your reviewer:
/cc @timuthy

Release note:

Add `MergeMode` for toggling highlighting of merge conflicts.

…ion and writing

…ications

Introduces `MergeMode` (Silent/Informative) and threads it through `threeWayMerge`, `threeWayMergeSection`, and `threeWayMergeSequence`. In `MergeModeInformative`, when an operator-overridden scalar value differs from the current GLK default, a `# glk default: <value> # <-- glk-managed` line comment is appended to the value node. For complex nodes (mappings/sequences), a head comment on the key node signals the divergence. `WriteComponentVectorFile`, `stripDefaultVersionComments`, and `defaultVersionCommentMarker` are deleted. Their functionality is now covered generically by `WriteObjectsToFilesystem(MergeModeInformative)``, which plain.go already calls directly. The corresponding test describe block is removed along with the now-unused imports. Operator-comments are retained.

…l-sites Existing callers pass `MergeModeSilent` (zero value, no behaviour change). plain.go passes `MergeModeInformative` so the components.yaml file gets GLK default annotations for operator-overridden component versions.

timuthy · 2026-04-02T14:05:05Z

/assign

timuthy

Thanks for taking care about of merge mode configuration!

pkg/apis/config/v1alpha1/validation/validation.go

pkg/apis/config/v1alpha1/types.go

timuthy · 2026-04-10T08:19:13Z

pkg/apis/config/v1alpha1/types.go

+// GetMergeMode returns the configured MergeMode, defaulting to MergeModeInformative.
+// It is safe to call on a nil receiver.
+func (c *LandscapeKitConfiguration) GetMergeMode() MergeMode {
+	if c != nil && c.MergeMode != nil {
+		return *c.MergeMode
+	}
+	return MergeModeInformative
+}


Use a default value assignment instead?

Currently we are not defaulting for any option - or wdym?

I meant in Gardener or Kubernetes APIs in general. It should belong to https://github.com/gardener/gardener-landscape-kit/blob/main/pkg/apis/config/v1alpha1/defaults.go.

pkg/components/types.go

timuthy · 2026-04-10T10:15:00Z

pkg/utils/files/writer_test.go

 		})
 	})

+	Describe("#WriteObjectsToFilesystem - MergeModeInformative", func() {


Can you make use of Context to run the different modes?

updated the tests, ptal

timuthy · 2026-04-10T10:46:33Z

pkg/utils/meta/merge.go

 				resultValue = currentValue
 				if oldExists {
 					mergeNodeComments(oldValue, newValueNode, resultValue)
+					if mode == configv1alpha1.MergeModeInformative && !nodesEqual(newValueNode, currentValue, false) {


Suggested change

if mode == configv1alpha1.MergeModeInformative && !nodesEqual(newValueNode, currentValue, false) {

if mode == configv1alpha1.MergeModeInformative && !nodesEqual(oldValue, newValueNode, false) && !nodesEqual(newValueNode, currentValue, false) {

Otherwise the annotation is added every time for customized values.

reworked the merge logic w.r.t. the default comments. ptal.

pkg/utils/meta/merge.go

timuthy · 2026-04-10T10:51:04Z

pkg/utils/meta/merge.go

+
+	// GLKDefaultPrefix is the comment prefix for GLK-managed default annotations.
+	// It is exported so callers can use it as the strip anchor when removing annotations.
+	GLKDefaultPrefix = "# glk default: "


Suggested change

GLKDefaultPrefix = "# glk default: "

GLKDefaultPrefix = "# Attention - new default: "

Something like this?

timuthy · 2026-04-10T11:24:23Z

pkg/utils/meta/merge.go

+			resultValue.LineComment = annotation
+		}
+	default:
+		resultKeyNode.HeadComment = glkManagedHeadComment(resultKeyNode.HeadComment)


The comment is not added for lists. Instead, when a default values of a list item is changed, the item is completely appended to the list.

Example:

t0: Default

- apiGroups: [ "core.gardener.cloud" ] apiVersions: [ "*" ] resources: [ "shoots" ] size: 750Ki

t1: Overwrite

- apiGroups: [ "core.gardener.cloud" ] apiVersions: [ "*" ] resources: [ "shoots" ] size: 850Ki

t2: Default

- apiGroups: [ "core.gardener.cloud" ] apiVersions: [ "*" ] resources: [ "shoots" ] size: 950Ki

t3: Result

- apiGroups: [ "core.gardener.cloud" ] apiVersions: [ "*" ] resources: [ "shoots" ] size: 850Ki - apiGroups: [ "core.gardener.cloud" ] apiVersions: [ "*" ] resources: [ "shoots" ] size: 950Ki

gardener-prow · 2026-04-10T11:32:13Z

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please ask for approval from timuthy. For more information see the Code Review Process.

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

gardener-prow · 2026-04-13T11:38:03Z

PR needs rebase.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

LucaBernstein added 5 commits April 1, 2026 11:36

Fix outdated comment in components.yaml

6cbb229

Use general WriteObjectsToFilesystem for plain image vector resolut…

d0e2810

…ion and writing

Correctly support slices during three-way-merge and retain user modif…

e60adcf

…ications

gardener-prow bot requested a review from timuthy April 1, 2026 14:34

gardener-prow bot added area/usability Usability related kind/enhancement Enhancement, improvement, extension cla: yes Indicates the PR's author has signed the cla-assistant.io CLA. size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. labels Apr 1, 2026

gardener-prow bot assigned timuthy Apr 2, 2026

timuthy requested changes Apr 10, 2026

View reviewed changes

Address review comments

c9f08ef

	if mode == configv1alpha1.MergeModeInformative && !nodesEqual(newValueNode, currentValue, false) {
	if mode == configv1alpha1.MergeModeInformative && !nodesEqual(oldValue, newValueNode, false) && !nodesEqual(newValueNode, currentValue, false) {

	GLKDefaultPrefix = "# glk default: "
	GLKDefaultPrefix = "# Attention - new default: "

Conversation

LucaBernstein commented Apr 1, 2026

Uh oh!

timuthy commented Apr 2, 2026

Uh oh!

timuthy left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

gardener-prow bot commented Apr 10, 2026

Uh oh!

gardener-prow bot commented Apr 13, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

timuthy left a comment •

edited

Loading