config: distinct resource/transport API versions.

api/envoy/api/v2/core/config_source.proto

@@ -15,9 +15,24 @@ option java_multiple_files = true;
 
 // [#protodoc-title: Configuration sources]
 
+// xDS API version. This is used to describe both resource and transport
+// protocol versions (in distinct configuration fields).
+enum ApiVersion {
+  // When not specified, we assume v2, to ease migration to Envoy's stable API
+  // versioning. If a client does not support v2 (e.g. due to deprecation), this
+  // is an invalid value.
+  AUTO = 0;
+
+  // Use xDS v2 API.
+  V2 = 1;
+
+  // Use xDS v3alpha API.
+  V3ALPHA = 2;
+}
+
 // API configuration source. This identifies the API type and cluster that Envoy
 // will use to fetch an xDS API.
-// [#next-free-field: 8]
+// [#next-free-field: 9]
 message ApiConfigSource {
   // APIs may be fetched via either REST or gRPC.
   enum ApiType {
@@ -43,8 +58,13 @@ message ApiConfigSource {
     DELTA_GRPC = 3;
   }
 
+  // API type (gRPC, REST, delta gRPC)
   ApiType api_type = 1 [(validate.rules).enum = {defined_only: true}];
 
+  // API version for xDS transport protocol. This describes the xDS gRPC/REST
+  // endpoint and version of [Delta]DiscoveryRequest/Response used on the wire.
+  ApiVersion transport_api_version = 8 [(validate.rules).enum = {defined_only: true}];
+
   // Cluster names should be used only with REST. If > 1
   // cluster is defined, clusters will be cycled through if any kind of failure
   // occurs.
@@ -105,18 +125,6 @@ message RateLimitSettings {
 // inotify for updates.
 // [#next-free-field: 7]
 message ConfigSource {
-  enum XdsApiVersion {
-    // use for describing explicitly that xDS API version is set automatically. In default, xDS API
-    // version is V2
-    AUTO = 0;
-
-    // use xDS v2 API
-    V2 = 1;
-
-    // use xDS v3alpha API
-    V3ALPHA = 2;
-  }
-
   oneof config_source_specifier {
     option (validate.required) = true;
 
@@ -163,6 +171,8 @@ message ConfigSource {
   // timeout applies). The default is 15s.
   google.protobuf.Duration initial_fetch_timeout = 4;
 
-  // API version for xDS endpoint
-  XdsApiVersion xds_api_version = 6;
+  // API version for xDS resources. This implies the type URLs that the client
+  // will request for resources and the resource type that the client will in
+  // turn expect to be delivered.
+  ApiVersion resource_api_version = 6 [(validate.rules).enum = {defined_only: true}];
 }

api/envoy/api/v3alpha/core/config_source.proto

@@ -17,9 +17,24 @@ option java_multiple_files = true;
 
 // [#protodoc-title: Configuration sources]
 
+// xDS API version. This is used to describe both resource and transport
+// protocol versions (in distinct configuration fields).
+enum ApiVersion {
+  // When not specified, we assume v2, to ease migration to Envoy's stable API
+  // versioning. If a client does not support v2 (e.g. due to deprecation), this
+  // is an invalid value.
+  AUTO = 0;
+
+  // Use xDS v2 API.
+  V2 = 1;
+
+  // Use xDS v3alpha API.
+  V3ALPHA = 2;
+}
+
 // API configuration source. This identifies the API type and cluster that Envoy
 // will use to fetch an xDS API.
-// [#next-free-field: 8]
+// [#next-free-field: 9]
 message ApiConfigSource {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.core.ApiConfigSource";
 
@@ -47,8 +62,13 @@ message ApiConfigSource {
     DELTA_GRPC = 3;
   }
 
+  // API type (gRPC, REST, delta gRPC)
   ApiType api_type = 1 [(validate.rules).enum = {defined_only: true}];
 
+  // API version for xDS transport protocol. This describes the xDS gRPC/REST
+  // endpoint and version of [Delta]DiscoveryRequest/Response used on the wire.
+  ApiVersion transport_api_version = 8 [(validate.rules).enum = {defined_only: true}];
+
   // Cluster names should be used only with REST. If > 1
   // cluster is defined, clusters will be cycled through if any kind of failure
   // occurs.
@@ -117,18 +137,6 @@ message RateLimitSettings {
 message ConfigSource {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.core.ConfigSource";
 
-  enum XdsApiVersion {
-    // use for describing explicitly that xDS API version is set automatically. In default, xDS API
-    // version is V2
-    AUTO = 0;
-
-    // use xDS v2 API
-    V2 = 1;
-
-    // use xDS v3alpha API
-    V3ALPHA = 2;
-  }
-
   oneof config_source_specifier {
     option (validate.required) = true;
 
@@ -175,6 +183,8 @@ message ConfigSource {
   // timeout applies). The default is 15s.
   google.protobuf.Duration initial_fetch_timeout = 4;
 
-  // API version for xDS endpoint
-  XdsApiVersion xds_api_version = 6;
+  // API version for xDS resources. This implies the type URLs that the client
+  // will request for resources and the resource type that the client will in
+  // turn expect to be delivered.
+  ApiVersion resource_api_version = 6 [(validate.rules).enum = {defined_only: true}];
 }

source/common/config/BUILD

@@ -64,6 +64,7 @@ envoy_cc_library(
     srcs = ["delta_subscription_impl.cc"],
     hdrs = ["delta_subscription_impl.h"],
     deps = [
+        ":api_version_lib",
         ":grpc_stream_lib",
         ":new_grpc_mux_lib",
         ":utility_lib",
@@ -136,6 +137,7 @@ envoy_cc_library(
     srcs = ["grpc_mux_impl.cc"],
     hdrs = ["grpc_mux_impl.h"],
     deps = [
+        ":api_version_lib",
         ":grpc_stream_lib",
         ":utility_lib",
         "//include/envoy/config:grpc_mux_interface",
@@ -197,6 +199,7 @@ envoy_cc_library(
         "http_api_protos",
     ],
     deps = [
+        ":api_version_lib",
         "//include/envoy/config:subscription_interface",
         "//include/envoy/event:dispatcher_interface",
         "//source/common/buffer:buffer_lib",
@@ -299,8 +302,14 @@ envoy_cc_library(
         "//source/common/protobuf",
         "@envoy_api//envoy/api/v2:pkg_cc_proto",
         "@envoy_api//envoy/api/v2/auth:pkg_cc_proto",
+        "@envoy_api//envoy/api/v2/core:pkg_cc_proto",
         "@envoy_api//envoy/api/v2/route:pkg_cc_proto",
+        "@envoy_api//envoy/api/v3alpha:pkg_cc_proto",
+        "@envoy_api//envoy/api/v3alpha/auth:pkg_cc_proto",
+        "@envoy_api//envoy/api/v3alpha/route:pkg_cc_proto",
         "@envoy_api//envoy/service/discovery/v2:pkg_cc_proto",
+        "@envoy_api//envoy/service/discovery/v3alpha:pkg_cc_proto",
+        "@envoy_api//envoy/service/route/v3alpha:pkg_cc_proto",
     ],
 )
 

source/common/config/grpc_mux_impl.h

@@ -13,6 +13,7 @@
 
 #include "common/common/cleanup.h"
 #include "common/common/logger.h"
+#include "common/config/api_version.h"
 #include "common/config/grpc_stream.h"
 #include "common/config/utility.h"
 
@@ -59,7 +60,7 @@ class GrpcMuxImpl : public GrpcMux,
   void onDiscoveryResponse(std::unique_ptr<envoy::api::v2::DiscoveryResponse>&& message) override;
   void onWriteable() override;
 
-  GrpcStream<envoy::api::v2::DiscoveryRequest, envoy::api::v2::DiscoveryResponse>&
+  GrpcStream<API_NO_BOOST(envoy::api::v2::DiscoveryRequest), envoy::api::v2::DiscoveryResponse>&
   grpcStreamForTest() {
     return grpc_stream_;
   }
@@ -102,7 +103,7 @@ class GrpcMuxImpl : public GrpcMux,
     // Watches on the returned resources for the API;
     std::list<GrpcMuxWatchImpl*> watches_;
     // Current DiscoveryRequest for API.
-    envoy::api::v2::DiscoveryRequest request_;
+    API_NO_BOOST(envoy::api::v2::DiscoveryRequest) request_;
     // Paused via pause()?
     bool paused_{};
     // Was a DiscoveryRequest elided during a pause?
@@ -115,7 +116,8 @@ class GrpcMuxImpl : public GrpcMux,
   void queueDiscoveryRequest(const std::string& queue_item);
   void clearRequestQueue();
 
-  GrpcStream<envoy::api::v2::DiscoveryRequest, envoy::api::v2::DiscoveryResponse> grpc_stream_;
+  GrpcStream<API_NO_BOOST(envoy::api::v2::DiscoveryRequest), envoy::api::v2::DiscoveryResponse>
+      grpc_stream_;
   const LocalInfo::LocalInfo& local_info_;
   const bool skip_subsequent_node_;
   bool first_stream_request_;

source/common/config/http_subscription_impl.cc

@@ -22,14 +22,15 @@ HttpSubscriptionImpl::HttpSubscriptionImpl(
     const std::string& remote_cluster_name, Event::Dispatcher& dispatcher,
     Runtime::RandomGenerator& random, std::chrono::milliseconds refresh_interval,
     std::chrono::milliseconds request_timeout, const Protobuf::MethodDescriptor& service_method,
-    SubscriptionCallbacks& callbacks, SubscriptionStats stats,
+    absl::string_view type_url, SubscriptionCallbacks& callbacks, SubscriptionStats stats,
     std::chrono::milliseconds init_fetch_timeout,
     ProtobufMessage::ValidationVisitor& validation_visitor)
     : Http::RestApiFetcher(cm, remote_cluster_name, dispatcher, random, refresh_interval,
                            request_timeout),
       callbacks_(callbacks), stats_(stats), dispatcher_(dispatcher),
       init_fetch_timeout_(init_fetch_timeout), validation_visitor_(validation_visitor) {
   request_.mutable_node()->CopyFrom(local_info.node());
+  request_.set_type_url(std::string(type_url));
   ASSERT(service_method.options().HasExtension(google::api::http));
   const auto& http_rule = service_method.options().GetExtension(google::api::http);
   path_ = http_rule.post();