ratelimit add support for custom http response code (#20520)

Signed-off-by: xiada <maxxd@qq.com>

Mirrored from https://github.com/envoyproxy/envoy @ 6c297a788b236309ebc329f29ebe534238ee24cd

envoy/extensions/filters/http/ratelimit/v3/BUILD

@@ -10,6 +10,7 @@ api_proto_package(
         "//envoy/config/ratelimit/v3:pkg",
         "//envoy/config/route/v3:pkg",
         "//envoy/type/metadata/v3:pkg",
+        "//envoy/type/v3:pkg",
         "@com_github_cncf_udpa//udpa/annotations:pkg",
     ],
 )

envoy/extensions/filters/http/ratelimit/v3/rate_limit.proto

@@ -6,6 +6,7 @@ import "envoy/config/core/v3/extension.proto";
 import "envoy/config/ratelimit/v3/rls.proto";
 import "envoy/config/route/v3/route_components.proto";
 import "envoy/type/metadata/v3/metadata.proto";
+import "envoy/type/v3/http_status.proto";
 
 import "google/protobuf/duration.proto";
 
@@ -23,7 +24,7 @@ option (udpa.annotations.file_status).package_version_status = ACTIVE;
 // Rate limit :ref:`configuration overview <config_http_filters_rate_limit>`.
 // [#extension: envoy.filters.http.ratelimit]
 
-// [#next-free-field: 10]
+// [#next-free-field: 11]
 message RateLimit {
   option (udpa.annotations.versioning).previous_message_type =
       "envoy.config.filter.http.rate_limit.v2.RateLimit";
@@ -111,6 +112,14 @@ message RateLimit {
   // in case of rate limiting (i.e. 429 responses).
   // Having this header not present potentially makes the request retriable.
   bool disable_x_envoy_ratelimited_header = 9;
+
+  // This field allows for a custom HTTP response status code to the downstream client when
+  // the request has been rate limited.
+  // Defaults to 429 (TooManyRequests).
+  //
+  // .. note::
+  //   If this is set to < 400, 429 will be used instead.
+  type.v3.HttpStatus rate_limited_status = 10;
 }
 
 // Global rate limiting :ref:`architecture overview <arch_overview_global_rate_limit>`.