From 9a7f73097e0dbf9ad6e21e3d045f0e0921f2e278 Mon Sep 17 00:00:00 2001
From: Joel Speed <Joel.speed@hotmail.co.uk>
Date: Mon, 6 Jan 2025 18:02:17 +0700
Subject: [PATCH] Prevent panic when informer receives
 cache.DeletedFinalStateUnknown (#7776)

---
 pkg/provider/azure_local_services.go | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/pkg/provider/azure_local_services.go b/pkg/provider/azure_local_services.go
index 5abf546c26..137e7feb92 100644
--- a/pkg/provider/azure_local_services.go
+++ b/pkg/provider/azure_local_services.go
@@ -351,7 +351,23 @@ func (az *Cloud) setUpEndpointSlicesInformer(informerFactory informers.SharedInf
 				}
 			},
 			DeleteFunc: func(obj interface{}) {
-				es := obj.(*discovery_v1.EndpointSlice)
+				var es *discovery_v1.EndpointSlice
+				switch v := obj.(type) {
+				case *discovery_v1.EndpointSlice:
+					es = v
+				case cache.DeletedFinalStateUnknown:
+					// We may miss the deletion event if the watch stream is disconnected and the object is deleted.
+					var ok bool
+					es, ok = v.Obj.(*discovery_v1.EndpointSlice)
+					if !ok {
+						klog.Errorf("Cannot convert to *discovery_v1.EndpointSlice: %T", v.Obj)
+						return
+					}
+				default:
+					klog.Errorf("Cannot convert to *discovery_v1.EndpointSlice: %T", v)
+					return
+				}
+
 				az.endpointSlicesCache.Delete(strings.ToLower(fmt.Sprintf("%s/%s", es.Namespace, es.Name)))
 			},
 		})