upstream: the cluster provoded load balancing policy could be configured as extension (#27512)

* upstream: the cluster provoded load balancing policy could be configured as extension

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

* address comments

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

---------

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

Mirrored from https://github.com/envoyproxy/envoy @ af9b04edc8349ee34fa21ab98b0965f8816f718d

BUILD

@@ -252,6 +252,7 @@ proto_library(
         "//envoy/extensions/internal_redirect/previous_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/safe_cross_scheme/v3:pkg",
         "//envoy/extensions/key_value/file_based/v3:pkg",
+        "//envoy/extensions/load_balancing_policies/cluster_provided/v3:pkg",
         "//envoy/extensions/load_balancing_policies/common/v3:pkg",
         "//envoy/extensions/load_balancing_policies/least_request/v3:pkg",
         "//envoy/extensions/load_balancing_policies/maglev/v3:pkg",

envoy/extensions/load_balancing_policies/cluster_provided/v3/BUILD

@@ -0,0 +1,9 @@
+# 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 = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+)

envoy/extensions/load_balancing_policies/cluster_provided/v3/cluster_provided.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+package envoy.extensions.load_balancing_policies.cluster_provided.v3;
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.load_balancing_policies.cluster_provided.v3";
+option java_outer_classname = "ClusterProvidedProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/load_balancing_policies/cluster_provided/v3;cluster_providedv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Cluster Provided Load Balancing Policy]
+// [#extension: envoy.load_balancing_policies.cluster_provided]
+
+// The cluster provided load balancing policy allows cluster to specify its own load balancing.
+// If this extension is configured, the target cluster must provide load balancer when the cluster
+// is created.
+//
+// ..note::
+//   Cluster provided load balancing policy could not be used as sub-policy of other hierarchical
+//   load balancing policies, such as subset load balancing policy.
+message ClusterProvided {
+}

versioning/BUILD

@@ -191,6 +191,7 @@ proto_library(
         "//envoy/extensions/internal_redirect/safe_cross_scheme/v3:pkg",
         "//envoy/extensions/key_value/file_based/v3:pkg",
         "//envoy/extensions/load_balancing_policies/client_side_weighted_round_robin/v3:pkg",
+        "//envoy/extensions/load_balancing_policies/cluster_provided/v3:pkg",
         "//envoy/extensions/load_balancing_policies/common/v3:pkg",
         "//envoy/extensions/load_balancing_policies/least_request/v3:pkg",
         "//envoy/extensions/load_balancing_policies/maglev/v3:pkg",