fix: handle passing namespace downstream more elegant

api/internal/target/kusttarget.go

@@ -29,13 +29,14 @@ import (
 
 // KustTarget encapsulates the entirety of a kustomization build.
 type KustTarget struct {
-	kustomization *types.Kustomization
-	kustFileName  string
-	ldr           ifc.Loader
-	validator     ifc.Validator
-	rFactory      *resmap.Factory
-	pLdr          *loader.Loader
-	origin        *resource.Origin
+	kustomization      *types.Kustomization
+	kustFileName       string
+	ldr                ifc.Loader
+	validator          ifc.Validator
+	rFactory           *resmap.Factory
+	pLdr               *loader.Loader
+	origin             *resource.Origin
+	inheritedNamespace string // For helm chart namespace inheritance without general propagation
 }
 
 // NewKustTarget returns a new instance of KustTarget.
@@ -127,10 +128,8 @@ func (kt *KustTarget) MakeCustomizedResMap() (resmap.ResMap, error) {
 }
 
 func (kt *KustTarget) makeCustomizedResMap() (resmap.ResMap, error) {
-	// Only track origin if we have Helm charts or build metadata is requested
-	// This optimization avoids unnecessary overhead when origins aren't needed
 	var origin *resource.Origin
-	if len(kt.kustomization.BuildMetadata) != 0 || len(kt.kustomization.HelmCharts) > 0 {
+	if len(kt.kustomization.BuildMetadata) != 0 {
 		origin = &resource.Origin{}
 	}
 	kt.origin = origin
@@ -498,10 +497,13 @@ func (kt *KustTarget) accumulateDirectory(
 	}
 	subKt.kustomization.BuildMetadata = kt.kustomization.BuildMetadata
 	subKt.origin = kt.origin
-	// Propagate namespace to child kustomization if child doesn't have one
-	// This ensures Helm charts in base kustomizations inherit namespace from overlays
-	if subKt.kustomization.Namespace == "" && kt.kustomization.Namespace != "" {
-		subKt.kustomization.Namespace = kt.kustomization.Namespace
+	// Pass down namespace context for helm chart inheritance, but don't set it on the kustomization
+	// This avoids the performance penalty of general namespace propagation while still supporting
+	// helm chart namespace inheritance from parent overlays
+	if kt.kustomization.Namespace != "" {
+		subKt.inheritedNamespace = kt.kustomization.Namespace
+	} else if kt.inheritedNamespace != "" {
+		subKt.inheritedNamespace = kt.inheritedNamespace
 	}
 	var bytes []byte
 	if openApiPath, exists := subKt.Kustomization().OpenAPI["path"]; exists {

api/internal/target/kusttarget_configplugin.go

@@ -168,8 +168,14 @@ var generatorConfigurators = map[builtinhelpers.BuiltinPluginType]func(
 			c.HelmChart = chart
 			// Pass kustomize namespace to helm
 			// Fixes https://github.com/kubernetes-sigs/kustomize/issues/5566
-			if c.HelmChart.Namespace == "" && kt.kustomization.Namespace != "" {
-				c.HelmChart.Namespace = kt.kustomization.Namespace
+			// Also check for inherited namespace context for nested kustomizations
+			if c.HelmChart.Namespace == "" {
+				if kt.kustomization.Namespace != "" {
+					c.HelmChart.Namespace = kt.kustomization.Namespace
+				} else if kt.inheritedNamespace != "" {
+					// For nested kustomizations, use inherited namespace from parent
+					c.HelmChart.Namespace = kt.inheritedNamespace
+				}
 			}
 			p := f()
 			if err = kt.configureBuiltinPlugin(p, c, bpt); err != nil {
@@ -460,3 +466,4 @@ var transformerConfigurators = map[builtinhelpers.BuiltinPluginType]func(
 		return nil, fmt.Errorf("valueadd keyword not yet defined")
 	},
 }
+