[route] Ignore port when picking host (#21323)

* Add an option to RouteConfiguration, when enabled, ignore port contained in host header during host matching.

Signed-off-by: Xin Zhuang <stevenzzz@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 2f99e0c9f83b6c91b42d215a148ed49ce0f174fd

envoy/config/route/v3/route.proto

@@ -22,7 +22,7 @@ option (udpa.annotations.file_status).package_version_status = ACTIVE;
 // * Routing :ref:`architecture overview <arch_overview_http_routing>`
 // * HTTP :ref:`router filter <config_http_filters_router>`
 
-// [#next-free-field: 14]
+// [#next-free-field: 15]
 message RouteConfiguration {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.RouteConfiguration";
 
@@ -129,6 +129,12 @@ message RouteConfiguration {
   // Specify a set of default request mirroring policies which apply to all routes under its virtual hosts.
   // Note that policies are not merged, the most specific non-empty one becomes the mirror policies.
   repeated RouteAction.RequestMirrorPolicy request_mirror_policies = 13;
+
+  // By default, port in :authority header (if any) is used in host matching.
+  // With this option enabled, Envoy will ignore the port number in the :authority header (if any) when picking VirtualHost.
+  // NOTE: this option will not strip the port number (if any) contained in route config
+  // :ref:`envoy_v3_api_msg_config.route.v3.VirtualHost`.domains field.
+  bool ignore_port_in_host_matching = 14;
 }
 
 message Vhds {