lua support cluster specifier extension (#31034)

* lua cluster specifier api

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix api format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* add validate for api filed

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix api format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* implement lua cluster specifier plugin

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* add example

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix format

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix example

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix review

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix dep ci

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* add changelog

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix review

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* fix ut

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

* add test

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

---------

Signed-off-by: wangkai19 <wangkai19@corp.netease.com>

Mirrored from https://github.com/envoyproxy/envoy @ 57f23d3092956972f2c23f869280310c7a65ca33

BUILD

@@ -309,6 +309,7 @@ proto_library(
         "//envoy/extensions/retry/host/omit_host_metadata/v3:pkg",
         "//envoy/extensions/retry/host/previous_hosts/v3:pkg",
         "//envoy/extensions/retry/priority/previous_priorities/v3:pkg",
+        "//envoy/extensions/router/cluster_specifiers/lua/v3:pkg",
         "//envoy/extensions/stat_sinks/graphite_statsd/v3:pkg",
         "//envoy/extensions/stat_sinks/open_telemetry/v3:pkg",
         "//envoy/extensions/stat_sinks/wasm/v3:pkg",

envoy/extensions/router/cluster_specifiers/lua/v3/BUILD

@@ -0,0 +1,12 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    deps = [
+        "//envoy/config/core/v3:pkg",
+        "@com_github_cncf_xds//udpa/annotations:pkg",
+    ],
+)

envoy/extensions/router/cluster_specifiers/lua/v3/lua.proto

@@ -0,0 +1,27 @@
+syntax = "proto3";
+
+package envoy.extensions.router.cluster_specifiers.lua.v3;
+
+import "envoy/config/core/v3/base.proto";
+
+import "udpa/annotations/status.proto";
+import "validate/validate.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.router.cluster_specifiers.lua.v3";
+option java_outer_classname = "LuaProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/router/cluster_specifiers/lua/v3;luav3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Lua]
+//
+// Lua cluster specifier :ref:`configuration reference documentation <config_http_cluster_specifier_lua>`.
+// [#extension: envoy.router.cluster_specifier_plugin.lua]
+
+message LuaConfig {
+  // The lua code that Envoy will execute to select cluster.
+  config.core.v3.DataSource source_code = 1 [(validate.rules).message = {required: true}];
+
+  // Default cluster. It will be used when the lua code execute failure.
+  string default_cluster = 2;
+}

versioning/BUILD

@@ -248,6 +248,7 @@ proto_library(
         "//envoy/extensions/retry/host/omit_host_metadata/v3:pkg",
         "//envoy/extensions/retry/host/previous_hosts/v3:pkg",
         "//envoy/extensions/retry/priority/previous_priorities/v3:pkg",
+        "//envoy/extensions/router/cluster_specifiers/lua/v3:pkg",
         "//envoy/extensions/stat_sinks/graphite_statsd/v3:pkg",
         "//envoy/extensions/stat_sinks/open_telemetry/v3:pkg",
         "//envoy/extensions/stat_sinks/wasm/v3:pkg",