fix(controller/subnet): controller crashes on subnets if gateway is u…

…nspecified and netpol are disabled (#4848)

Signed-off-by: SkalaNetworks <[email protected]>

pkg/controller/subnet.go

@@ -70,14 +70,16 @@ func (c *Controller) enqueueUpdateSubnet(oldObj, newObj interface{}) {
 		return
 	}
 
-	if newSubnet.Spec.Gateway != oldSubnet.Spec.Gateway ||
-		newSubnet.Status.U2OInterconnectionIP != oldSubnet.Status.U2OInterconnectionIP {
-		policies, err := c.npsLister.List(labels.Everything())
-		if err != nil {
-			klog.Errorf("failed to list network policies: %v", err)
-		} else {
-			for _, np := range policies {
-				c.enqueueAddNp(np)
+	// Trigger network policy refresh only if they are enabled, otherwise the lister will be nil
+	if c.npsLister != nil {
+		if newSubnet.Spec.Gateway != oldSubnet.Spec.Gateway || newSubnet.Status.U2OInterconnectionIP != oldSubnet.Status.U2OInterconnectionIP {
+			policies, err := c.npsLister.List(labels.Everything())
+			if err != nil {
+				klog.Errorf("failed to list network policies: %v", err)
+			} else {
+				for _, np := range policies {
+					c.enqueueAddNp(np)
+				}
 			}
 		}
 	}