3 files changed, 153 insertions, 3 deletions
diff --git a/include/grpcpp/ext/csm_observability.h b/include/grpcpp/ext/csm_observability.h
index c06783391b..a3b50a7238 100644
--- a/include/grpcpp/ext/csm_observability.h
+++ b/include/grpcpp/ext/csm_observability.h
@@ -28,9 +28,14 @@
 #include "absl/strings/string_view.h"
 #include "opentelemetry/sdk/metrics/meter_provider.h"
 
-#include "src/cpp/ext/otel/otel_plugin.h"
+#include <grpcpp/ext/otel_plugin.h>
 
 namespace grpc {
+
+namespace internal {
+class OpenTelemetryPluginBuilderImpl;
+}  // namespace internal
+
 namespace experimental {
 
 // This is a no-op at present, but in the future, this object would be useful
@@ -41,6 +46,8 @@ class CsmObservability {};
 // for a binary running on CSM.
 class CsmObservabilityBuilder {
  public:
+  CsmObservabilityBuilder();
+  ~CsmObservabilityBuilder();
   CsmObservabilityBuilder& SetMeterProvider(
       std::shared_ptr<opentelemetry::sdk::metrics::MeterProvider>
           meter_provider);
@@ -80,9 +87,19 @@ class CsmObservabilityBuilder {
   absl::StatusOr<CsmObservability> BuildAndRegister();
 
  private:
-  internal::OpenTelemetryPluginBuilder builder_;
+  std::unique_ptr<grpc::internal::OpenTelemetryPluginBuilderImpl> builder_;
 };
 
+/// Creates an OpenTelemetryPluginOption that would add additional labels on
+/// gRPC metrics to enhance observability for CSM users.
+///
+/// Sample Usage -
+/// OpenTelemetryPluginBuilder()
+///     .SetMeterProvider(provider)
+///     .AddPluginOption(MakeCsmOpenTelemetryPluginOption())
+///     .BuildAndRegisterGlobal();
+std::unique_ptr<OpenTelemetryPluginOption> MakeCsmOpenTelemetryPluginOption();
+
 }  // namespace experimental
 }  // namespace grpc
 
diff --git a/include/grpcpp/ext/otel_plugin.h b/include/grpcpp/ext/otel_plugin.h
new file mode 100644
index 0000000000..51afdaa83d
--- /dev/null
+++ b/include/grpcpp/ext/otel_plugin.h
@@ -0,0 +1,127 @@
+//
+//
+// Copyright 2023 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//
+
+#ifndef GRPCPP_EXT_OTEL_PLUGIN_H
+#define GRPCPP_EXT_OTEL_PLUGIN_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+
+#include "absl/functional/any_invocable.h"
+#include "absl/status/status.h"
+#include "absl/strings/string_view.h"
+#include "opentelemetry/metrics/meter_provider.h"
+
+namespace grpc {
+
+namespace internal {
+class OpenTelemetryPluginBuilderImpl;
+}  // namespace internal
+
+class OpenTelemetryPluginOption {
+ public:
+  virtual ~OpenTelemetryPluginOption() = default;
+};
+
+/// The most common way to use this API is -
+///
+/// OpenTelemetryPluginBuilder().SetMeterProvider(provider).BuildAndRegister();
+///
+/// The set of instruments available are -
+/// grpc.client.attempt.started
+/// grpc.client.attempt.duration
+/// grpc.client.attempt.sent_total_compressed_message_size
+/// grpc.client.attempt.rcvd_total_compressed_message_size
+/// grpc.server.call.started
+/// grpc.server.call.duration
+/// grpc.server.call.sent_total_compressed_message_size
+/// grpc.server.call.rcvd_total_compressed_message_size
+class OpenTelemetryPluginBuilder {
+ public:
+  /// Metrics
+  static constexpr absl::string_view kClientAttemptStartedInstrumentName =
+      "grpc.client.attempt.started";
+  static constexpr absl::string_view kClientAttemptDurationInstrumentName =
+      "grpc.client.attempt.duration";
+  static constexpr absl::string_view
+      kClientAttemptSentTotalCompressedMessageSizeInstrumentName =
+          "grpc.client.attempt.sent_total_compressed_message_size";
+  static constexpr absl::string_view
+      kClientAttemptRcvdTotalCompressedMessageSizeInstrumentName =
+          "grpc.client.attempt.rcvd_total_compressed_message_size";
+  static constexpr absl::string_view kServerCallStartedInstrumentName =
+      "grpc.server.call.started";
+  static constexpr absl::string_view kServerCallDurationInstrumentName =
+      "grpc.server.call.duration";
+  static constexpr absl::string_view
+      kServerCallSentTotalCompressedMessageSizeInstrumentName =
+          "grpc.server.call.sent_total_compressed_message_size";
+  static constexpr absl::string_view
+      kServerCallRcvdTotalCompressedMessageSizeInstrumentName =
+          "grpc.server.call.rcvd_total_compressed_message_size";
+
+  OpenTelemetryPluginBuilder();
+  ~OpenTelemetryPluginBuilder();
+  /// If `SetMeterProvider()` is not called, no metrics are collected.
+  OpenTelemetryPluginBuilder& SetMeterProvider(
+      std::shared_ptr<opentelemetry::metrics::MeterProvider> meter_provider);
+  /// If set, \a target_attribute_filter is called per channel to decide whether
+  /// to record the target attribute on client or to replace it with "other".
+  /// This helps reduce the cardinality on metrics in cases where many channels
+  /// are created with different targets in the same binary (which might happen
+  /// for example, if the channel target string uses IP addresses directly).
+  OpenTelemetryPluginBuilder& SetTargetAttributeFilter(
+      absl::AnyInvocable<bool(absl::string_view /*target*/) const>
+          target_attribute_filter);
+  /// If set, \a generic_method_attribute_filter is called per call with a
+  /// generic method type to decide whether to record the method name or to
+  /// replace it with "other". Non-generic or pre-registered methods remain
+  /// unaffected. If not set, by default, generic method names are replaced with
+  /// "other" when recording metrics.
+  OpenTelemetryPluginBuilder& SetGenericMethodAttributeFilter(
+      absl::AnyInvocable<bool(absl::string_view /*generic_method*/) const>
+          generic_method_attribute_filter);
+  /// Add a plugin option to add to the opentelemetry plugin being built. At
+  /// present, this type is an opaque type. Ownership of \a option is
+  /// transferred when `AddPluginOption` is invoked. A maximum of 64 plugin
+  /// options can be added.
+  OpenTelemetryPluginBuilder& AddPluginOption(
+      std::unique_ptr<OpenTelemetryPluginOption> option);
+  /// Registers a global plugin that acts on all channels and servers running on
+  /// the process.
+  absl::Status BuildAndRegisterGlobal();
+
+ private:
+  std::unique_ptr<internal::OpenTelemetryPluginBuilderImpl> impl_;
+};
+
+namespace experimental {
+// TODO(yashykt): Delete this after the 1.62 release.
+GRPC_DEPRECATED(
+    "Use grpc::OpenTelemetryPluginBuilder instead. The experimental version "
+    "will be deleted after the 1.62 release.")
+typedef grpc::OpenTelemetryPluginBuilder OpenTelemetryPluginBuilder;
+}  // namespace experimental
+
+}  // namespace grpc
+
+#endif  // GRPCPP_EXT_OTEL_PLUGIN_H
diff --git a/include/grpcpp/ext/proto_server_reflection_plugin.h b/include/grpcpp/ext/proto_server_reflection_plugin.h
index 2e3964c957..b1cbb5a67c 100644
--- a/include/grpcpp/ext/proto_server_reflection_plugin.h
+++ b/include/grpcpp/ext/proto_server_reflection_plugin.h
@@ -19,11 +19,15 @@
 #ifndef GRPCPP_EXT_PROTO_SERVER_REFLECTION_PLUGIN_H
 #define GRPCPP_EXT_PROTO_SERVER_REFLECTION_PLUGIN_H
 
+#include <memory>
+
 #include <grpcpp/impl/server_builder_plugin.h>
 #include <grpcpp/support/config.h>
 
 namespace grpc {
 class ProtoServerReflection;
+class ProtoServerReflectionBackend;
+class ProtoServerReflectionV1;
 class ServerInitializer;
 
 namespace reflection {
@@ -39,7 +43,9 @@ class ProtoServerReflectionPlugin : public grpc::ServerBuilderPlugin {
   bool has_sync_methods() const override;
 
  private:
-  std::shared_ptr<grpc::ProtoServerReflection> reflection_service_;
+  std::shared_ptr<grpc::ProtoServerReflectionBackend> backend_;
+  std::shared_ptr<grpc::ProtoServerReflection> reflection_service_v1alpha_;
+  std::shared_ptr<grpc::ProtoServerReflectionV1> reflection_service_v1_;
 };
 
 /// Add proto reflection plugin to \a ServerBuilder.