envoy grpc: overridable host (#12338)

Add authority field in envoy grpc message to override the default host name as cluster name.

Risk Level: Low
Testing:
Docs Changes:
Release Notes:
Fix #12116

Signed-off-by: Yuchen Dai <silentdai@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ 29b49276db0812b566d143a79996848819248428

envoy/config/core/v3/grpc_service.proto

@@ -36,6 +36,12 @@ message GrpcService {
     // in the :ref:`Cluster <envoy_api_msg_config.cluster.v3.Cluster>` :ref:`transport_socket
     // <envoy_api_field_config.cluster.v3.Cluster.transport_socket>`.
     string cluster_name = 1 [(validate.rules).string = {min_bytes: 1}];
+
+    // The `:authority` header in the grpc request. If this field is not set, the authority header value will be `cluster_name`.
+    // Note that this authority does not override the SNI. The SNI is provided by the transport socket of the cluster.
+    string authority = 2
+        [(validate.rules).string =
+             {min_bytes: 0 max_bytes: 16384 well_known_regex: HTTP_HEADER_VALUE strict: false}];
   }
 
   // [#next-free-field: 9]

envoy/config/core/v4alpha/grpc_service.proto

@@ -36,6 +36,12 @@ message GrpcService {
     // in the :ref:`Cluster <envoy_api_msg_config.cluster.v4alpha.Cluster>` :ref:`transport_socket
     // <envoy_api_field_config.cluster.v4alpha.Cluster.transport_socket>`.
     string cluster_name = 1 [(validate.rules).string = {min_bytes: 1}];
+
+    // The `:authority` header in the grpc request. If this field is not set, the authority header value will be `cluster_name`.
+    // Note that this authority does not override the SNI. The SNI is provided by the transport socket of the cluster.
+    string authority = 2
+        [(validate.rules).string =
+             {min_bytes: 0 max_bytes: 16384 well_known_regex: HTTP_HEADER_VALUE strict: false}];
   }
 
   // [#next-free-field: 9]