✨ Add ListenerConfig for metrics server options (kubernetes-sigs#2519)

* Add ListenerConfig for metrics * Address feedback on backwards compatibility and full cross feature functionality. * Address feedback * Add error handling * Update pkg/metrics/server/server.go Co-authored-by: Stefan Büringer <4662360+sbueringer@users.noreply.github.com> --------- Co-authored-by: Stefan Büringer <4662360+sbueringer@users.noreply.github.com>

Author: tomelliot16

pkg/metrics/server/server.go

@@ -101,6 +101,9 @@ type Options struct {
 // TLSOpts is used to allow configuring the TLS config used for the server.
 // This also allows providing a certificate via GetCertificate.
 TLSOpts []func(*tls.Config)
+
+// ListenConfig contains options for listening to an address on the metric server.
+ListenConfig net.ListenConfig
 }
 
 // Filter is a func that is added around metrics and extra handlers on the metrics server.
@@ -249,7 +252,7 @@ func (s *defaultServer) Start(ctx context.Context) error {
 
 func (s *defaultServer) createListener(ctx context.Context, log logr.Logger) (net.Listener, error) {
 if !s.options.SecureServing {
-return net.Listen("tcp", s.options.BindAddress)
+return s.options.ListenConfig.Listen(ctx, "tcp", s.options.BindAddress)
 }
 
 cfg := &tls.Config{ //nolint:gosec
@@ -302,7 +305,12 @@ func (s *defaultServer) createListener(ctx context.Context, log logr.Logger) (ne
 cfg.Certificates = []tls.Certificate{keyPair}
 }
 
-return tls.Listen("tcp", s.options.BindAddress, cfg)
+l, err := s.options.ListenConfig.Listen(ctx, "tcp", s.options.BindAddress)
+if err != nil {
+return nil, err
+}
+
+return tls.NewListener(l, cfg), nil
 }
 
 func (s *defaultServer) GetBindAddr() string {