layer1: guard router informer maps step 6

pkg/router/functionReferenceResolver.go

@@ -18,6 +18,7 @@ package router
 
 import (
 	"fmt"
+	"sync"
 	"time"
 
 	"go.uber.org/zap"
@@ -35,6 +36,7 @@ type (
 		// FunctionReference -> function metadata
 		refCache     *cache.Cache[namespacedTriggerReference, resolveResult]
 		funcInformer map[string]k8sCache.SharedIndexInformer
+		mu           sync.RWMutex
 		logger       *zap.Logger
 		// store    k8sCache.Store
 	}
@@ -120,12 +122,21 @@ func (frr *functionReferenceResolver) resolve(trigger fv1.HTTPTrigger) (*resolve
 }
 
 func (frr *functionReferenceResolver) getInformerByNamespace(namespace string) (k8sCache.SharedIndexInformer, error) {
+	frr.mu.RLock()
+	defer frr.mu.RUnlock()
+
 	if informer, ok := frr.funcInformer[namespace]; ok {
 		return informer, nil
 	}
 	return nil, fmt.Errorf("informer for namespace %s not found", namespace)
 }
 
+func (frr *functionReferenceResolver) addInformer(namespace string, informer k8sCache.SharedIndexInformer) {
+	frr.mu.Lock()
+	defer frr.mu.Unlock()
+	frr.funcInformer[namespace] = informer
+}
+
 // resolveByName simply looks up function by name in a namespace.
 func (frr *functionReferenceResolver) resolveByName(namespace, name string) (*resolveResult, error) {
 	// get function from cache