codegen kebab case conversion (#58529)

Signed-off-by: Rama Chavali <[email protected]>

Author: ramaraochavali

pilot/pkg/networking/util/util.go

@@ -22,7 +22,6 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"sync"
 
 	core "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
 	endpoint "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3"
@@ -47,11 +46,11 @@ import (
 	"istio.io/istio/pilot/pkg/util/protoconv"
 	"istio.io/istio/pkg/config"
 	"istio.io/istio/pkg/config/constants"
+	"istio.io/istio/pkg/config/schema/gvk"
 	kubelabels "istio.io/istio/pkg/kube/labels"
 	"istio.io/istio/pkg/log"
 	pm "istio.io/istio/pkg/model"
 	"istio.io/istio/pkg/proto/merge"
-	"istio.io/istio/pkg/util/strcase"
 	"istio.io/istio/pkg/wellknown"
 )
 
@@ -93,20 +92,6 @@ const (
 	AlpnOverrideMetadataKey = "alpn_override"
 )
 
-// kindToKebabCache caches the conversion from CamelCase Kind to kebab-case.
-// This avoids repeated string allocations for the same Kind values.
-var kindToKebabCache sync.Map
-
-// getKebabKind returns the kebab-case version of a Kind, using a cache to avoid repeated allocations.
-func getKebabKind(kind string) string {
-	if cached, ok := kindToKebabCache.Load(kind); ok {
-		return cached.(string)
-	}
-	kebab := strcase.CamelCaseToKebabCase(kind)
-	kindToKebabCache.Store(kind, kebab)
-	return kebab
-}
-
 // ALPNH2Only advertises that Proxy is going to use HTTP/2 when talking to the cluster.
 var ALPNH2Only = pm.ALPNH2Only
 
@@ -376,7 +361,7 @@ func AddConfigInfoMetadata(metadata *core.Metadata, config config.Meta) *core.Me
 	}
 
 	s := "/apis/" + config.GroupVersionKind.Group + "/" + config.GroupVersionKind.Version + "/namespaces/" + config.Namespace + "/" +
-		getKebabKind(config.GroupVersionKind.Kind) + "/" + config.Name
+		gvk.KebabKind(config.GroupVersionKind.Kind) + "/" + config.Name
 
 	istioMeta, ok := metadata.FilterMetadata[IstioMetadataKey]
 	if !ok {

pkg/config/schema/codegen/common.go

@@ -28,6 +28,7 @@ import (
 	"istio.io/istio/pilot/pkg/features"
 	"istio.io/istio/pkg/config/schema/ast"
 	"istio.io/istio/pkg/test/env"
+	"istio.io/istio/pkg/util/strcase"
 )
 
 func Run() error {
@@ -65,9 +66,21 @@ func Run() error {
 		{Resource: &ast.Resource{Identifier: "ServiceImport", Plural: "serviceimports", Version: features.MCSAPIVersion, Group: features.MCSAPIGroup}},
 	}, inp.Entries...)
 
+	// Build a deduplicated list of Kind names for KebabKind function
+	seenKinds := make(map[string]bool)
+	var uniqueKinds []string
+	for _, e := range inp.Entries {
+		if !seenKinds[e.Resource.Kind] {
+			seenKinds[e.Resource.Kind] = true
+			uniqueKinds = append(uniqueKinds, e.Resource.Kind)
+		}
+	}
+	sort.Strings(uniqueKinds)
+
 	return errors.Join(
 		writeTemplate("pkg/config/schema/gvk/resources.gen.go", gvkTemplate, map[string]any{
 			"Entries":     inp.Entries,
+			"UniqueKinds": uniqueKinds,
 			"PackageName": "gvk",
 		}),
 		writeTemplate("pkg/config/schema/gvr/resources.gen.go", gvrTemplate, map[string]any{
@@ -125,9 +138,15 @@ func writeTemplate(path, tmpl string, i any) error {
 	return c.Run()
 }
 
+// camelCaseToKebabCase wraps strcase.CamelCaseToKebabCase for use in templates.
+func camelCaseToKebabCase(s string) string {
+	return strcase.CamelCaseToKebabCase(s)
+}
+
 func applyTemplate(tmpl string, i any) (string, error) {
 	t := template.New("tmpl").Funcs(template.FuncMap{
-		"contains": strings.Contains,
+		"contains":  strings.Contains,
+		"kebabcase": camelCaseToKebabCase,
 	})
 
 	t2 := template.Must(t.Parse(tmpl))

pkg/config/schema/codegen/templates/gvk.go.tmpl

@@ -86,3 +86,15 @@ func MustFromGVR(g schema.GroupVersionResource) config.GroupVersionKind {
 	}
 	return r
 }
+
+// KebabKind returns the kebab-case version of a Kind string.
+// This is a generated mapping to avoid runtime allocations from string conversion.
+func KebabKind(k string) string {
+	switch k {
+{{- range .UniqueKinds }}
+	case "{{.}}":
+		return "{{ kebabcase . }}"
+{{- end }}
+	}
+	return ""
+}

pkg/config/schema/gvk/resources.gen.go

@@ -68,6 +68,16 @@ func CamelCaseToKebabCase(s string) string {
 		return "http-route"
 	case "HTTPAPISpecBinding":
 		return "http-api-spec-binding"
+	case "GRPCRoute":
+		return "grpc-route"
+	case "TCPRoute":
+		return "tcp-route"
+	case "TLSRoute":
+		return "tls-route"
+	case "UDPRoute":
+		return "udp-route"
+	case "BackendTLSPolicy":
+		return "backend-tls-policy"
 	default:
 		var out bytes.Buffer
 		for i := range s {