better readiness check

Signed-off-by: Wei Weng <Wei.Weng@microsoft.com>

Author: Wei Weng

cmd/hubagent/main.go

@@ -20,7 +20,6 @@ import (
 	"flag"
 	"fmt"
 	"math"
-	"net/http"
 	"os"
 	"strings"
 	"sync"
@@ -151,20 +150,7 @@ func main() {
 		klog.ErrorS(err, "unable to set up health check")
 		exitWithErrorFunc()
 	}
-	// Add a readiness check that verifies ResourceInformer is ready
-	// This prevents webhook from accepting requests before discovery cache is populated
-	if err := mgr.AddReadyzCheck("readyz", func(req *http.Request) error {
-		// First check basic health
-		if err := healthz.Ping(req); err != nil {
-			return err
-		}
-		// Then verify ResourceInformer cache is synced (if webhook is enabled)
-		// This prevents webhook from accepting requests before discovery cache is populated
-		if opts.EnableWebhook && validator.ResourceInformer != nil {
-			return webhook.ResourceInformerReadinessChecker(validator.ResourceInformer)(req)
-		}
-		return nil
-	}); err != nil {
+	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
 		klog.ErrorS(err, "unable to set up ready check")
 		exitWithErrorFunc()
 	}
@@ -179,10 +165,19 @@ func main() {
 
 	ctx := ctrl.SetupSignalHandler()
 	if err := workload.SetupControllers(ctx, &wg, mgr, config, opts); err != nil {
-		klog.ErrorS(err, "unable to set up ready check")
+		klog.ErrorS(err, "unable to set up controllers")
 		exitWithErrorFunc()
 	}
 
+	// Add webhook readiness check AFTER controllers are set up (when ResourceInformer is initialized)
+	// This prevents webhook from accepting requests before discovery cache is populated
+	if opts.EnableWebhook {
+		if err := mgr.AddReadyzCheck("webhook-cache", webhook.ResourceInformerReadinessChecker(validator.ResourceInformer)); err != nil {
+			klog.ErrorS(err, "unable to set up webhook readiness check")
+			exitWithErrorFunc()
+		}
+	}
+
 	// +kubebuilder:scaffold:builder
 
 	wg.Add(1)