Revert "Revert "GCP Observability: Add plugin registry API"" (#30766)

* Revert "Revert "GCP Observability: Add plugin registry API (#30571)" (#30765)"

This reverts commit b8fde2ab47.

* Remove gcp observability target from header

bazel/grpc_deps.bzl

@@ -170,6 +170,16 @@ def grpc_deps():
         actual = "@io_opencensus_cpp//opencensus/tags:context_util",
     )
 
+    native.bind(
+        name = "opencensus-trace-stackdriver_exporter",
+        actual = "@io_opencensus_cpp//opencensus/exporters/trace/stackdriver:stackdriver_exporter",
+    )
+
+    native.bind(
+        name = "opencensus-stats-stackdriver_exporter",
+        actual = "@io_opencensus_cpp//opencensus/exporters/stats/stackdriver:stackdriver_exporter",
+    )
+
     native.bind(
         name = "libuv",
         actual = "@com_github_libuv_libuv//:libuv",

src/cpp/ext/gcp/BUILD

@@ -0,0 +1,53 @@
+# gRPC Bazel BUILD file.
+#
+# Copyright 2022 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.
+
+load(
+    "//bazel:grpc_build_system.bzl",
+    "grpc_cc_library",
+)
+
+licenses(["reciprocal"])
+
+package(
+    default_visibility = ["//visibility:private"],
+    features = [
+        "layering_check",
+        "-parse_headers",
+    ],
+)
+
+# This is an EXPERIMENTAL target subject to change.
+grpc_cc_library(
+    name = "observability",
+    srcs = [
+        "observability.cc",
+    ],
+    hdrs = [
+        "observability.h",
+    ],
+    external_deps = [
+        "opencensus-trace",
+        "opencensus-trace-stackdriver_exporter",
+        "opencensus-stats-stackdriver_exporter",
+    ],
+    language = "c++",
+    tags = ["nofixdeps"],
+    visibility = ["//test:__subpackages__"],
+    deps = [
+        "//:gpr",
+        "//:grpc_opencensus_plugin",
+    ],
+)

src/cpp/ext/gcp/observability.cc

@@ -0,0 +1,65 @@
+//
+// Copyright 2022 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.
+//
+
+#include <grpc/support/port_platform.h>
+
+#include "src/cpp/ext/gcp/observability.h"
+
+#include <stdint.h>
+
+#include <utility>
+
+#include "opencensus/exporters/stats/stackdriver/stackdriver_exporter.h"
+#include "opencensus/exporters/trace/stackdriver/stackdriver_exporter.h"
+#include "opencensus/trace/sampler.h"
+#include "opencensus/trace/trace_config.h"
+
+#include <grpcpp/opencensus.h>
+
+namespace grpc {
+namespace experimental {
+
+namespace {
+// TODO(yashykt): These constants are currently derived from the example at
+// https://cloud.google.com/traffic-director/docs/observability-proxyless#c++.
+// We might want these to be configurable.
+constexpr uint32_t kMaxAttributes = 128;
+constexpr uint32_t kMaxAnnotations = 128;
+constexpr uint32_t kMaxMessageEvents = 128;
+constexpr uint32_t kMaxLinks = 128;
+}  // namespace
+
+void GcpObservabilityInit() {
+  // TODO(yashykt): Add code for gRPC config parsing
+  grpc::RegisterOpenCensusPlugin();
+  grpc::RegisterOpenCensusViewsForExport();
+  // TODO(yashykt): Setup tracing and stats exporting only if enabled in config.
+  // TODO(yashykt): Get probability from config
+  opencensus::trace::TraceConfig::SetCurrentTraceParams(
+      {kMaxAttributes, kMaxAnnotations, kMaxMessageEvents, kMaxLinks,
+       opencensus::trace::ProbabilitySampler(1.0)});
+  opencensus::exporters::trace::StackdriverOptions trace_opts;
+  // TODO(yashykt): Set up project ID based on config
+  opencensus::exporters::trace::StackdriverExporter::Register(
+      std::move(trace_opts));
+  opencensus::exporters::stats::StackdriverOptions stats_opts;
+  // TODO(yashykt): Set up project ID based on config
+  opencensus::exporters::stats::StackdriverExporter::Register(
+      std::move(stats_opts));
+}
+
+}  // namespace experimental
+}  // namespace grpc

src/cpp/ext/gcp/observability.h

@@ -0,0 +1,33 @@
+//
+// Copyright 2022 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 GRPC_INTERNAL_CPP_EXT_GCP_OBSERVABILITY_GCP_OBSERVABILITY_H
+#define GRPC_INTERNAL_CPP_EXT_GCP_OBSERVABILITY_GCP_OBSERVABILITY_H
+
+// TODO(yashykt): This file would have been in the top include/grpcpp directory
+// instead of in src/, but I'm not yet sure about the naming, so keeping it here
+// till we decide.
+
+namespace grpc {
+namespace experimental {
+
+// Initialize GCP Observability for gRPC.
+void GcpObservabilityInit();
+
+}  // namespace experimental
+}  // namespace grpc
+
+#endif  // GRPC_INTERNAL_CPP_EXT_GCP_OBSERVABILITY_GCP_OBSERVABILITY_H

test/cpp/ext/gcp/BUILD

@@ -0,0 +1,34 @@
+# Copyright 2022 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.
+
+load("//bazel:grpc_build_system.bzl", "grpc_cc_test", "grpc_package")
+
+licenses(["notice"])
+
+grpc_package(name = "test/cpp/ext/gcp")
+
+grpc_cc_test(
+    name = "observability_test",
+    srcs = [
+        "observability_test.cc",
+    ],
+    external_deps = [
+        "gtest",
+    ],
+    language = "C++",
+    deps = [
+        "//src/cpp/ext/gcp:observability",
+        "//test/cpp/util:test_util",
+    ],
+)

test/cpp/ext/gcp/observability_test.cc

@@ -0,0 +1,36 @@
+//
+// Copyright 2022 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.
+//
+
+#include "src/cpp/ext/gcp/observability.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "test/core/util/test_config.h"
+
+namespace {
+
+TEST(GcpObservabilityTest, RegistrationTest) {
+  grpc::experimental::GcpObservabilityInit();
+}
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  grpc::testing::TestEnvironment env(&argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

tools/buildgen/extract_metadata_from_bazel_xml.py

@@ -655,7 +655,8 @@ def _exclude_unwanted_cc_tests(tests: List[str]) -> List[str]:
     tests = [
         test for test in tests
         if not test.startswith('test/cpp/ext/filters/census:') and
-        not test.startswith('test/core/xds:xds_channel_stack_modifier_test')
+        not test.startswith('test/core/xds:xds_channel_stack_modifier_test') and
+        not test.startswith('test/cpp/ext/gcp:')
     ]
 
     # missing opencensus/stats/stats.h