impl(pubsub-otel): add zipkin example (#284)

pubsub-open-telemetry/CMakeLists.txt

@@ -41,6 +41,13 @@ add_executable(publisher publisher.cc)
 target_compile_features(publisher PRIVATE cxx_std_14)
 target_link_libraries(publisher PRIVATE publisher_helper parse_args)
 
+add_executable(publisher_zipkin publisher_zipkin.cc)
+target_compile_features(publisher_zipkin PRIVATE cxx_std_14)
+target_link_libraries(
+    publisher_zipkin
+    PRIVATE publisher_helper parse_args
+            opentelemetry-cpp::opentelemetry_exporter_zipkin_trace)
+
 add_executable(quickstart quickstart.cc)
 target_compile_features(quickstart PRIVATE cxx_std_14)
 target_link_libraries(quickstart PRIVATE google-cloud-cpp::pubsub

pubsub-open-telemetry/publisher.md

@@ -4,32 +4,31 @@ The publisher application lets the user configure a tracing enabled Pub/Sub
 Publisher client to see how different configuration settings change the produced
 telemetry data.
 
-## Example traces
+For setup instructions, refer to the [README.md](README.md).
+
+## Cloud Trace
 
-### Cloud Trace
+### Example traces
 
 To find the traces, navigate to the Cloud Trace UI.
 
 #### Publish trace
 
-![Screenshot of the publish span in the Cloud Trace UI running publisher.](assets/publish_span.png)
+![Screenshot of the publish span in the Cloud Trace UI.](assets/publish_span.png)
 
 #### Create trace
 
-![Screenshot of the create span in the Cloud Trace UI running publisher.](assets/create_span.png)
+![Screenshot of the create span in the Cloud Trace UI.](assets/create_span.png)
 
 ## Build and run
 
-For setup instructions, refer to the [README.md](README.md).
-
 ### Using CMake and Vcpkg
 
 #### Run basic publisher examples
 
 ```shell
 .build/publisher [project-name] [topic-id]
 .build/publisher [project-name] [topic-id] -n 1000
-.build/publisher [project-name] [topic-id] --message-size 0
 .build/publisher [project-name] [topic-id] --tracing-rate 0.01 -n 10
 ```
 
@@ -71,13 +70,54 @@ A simple publisher application with Open Telemetery enabled:
   --max-batch-messages arg        pubsub::MaxBatchMessagesOption value
 ```
 
-### Using Bazel
+## Zipkin
+
+Zipkin exporter is only supported by CMake at the moment.
+
+### Setup
+
+If you do not already, have one create a local Zipkin instance.
+
+#### (optional) Create a local Zipkin instance.
+
+To run Zipkin on the host `http://localhost:9411`
+
+```shell
+docker run -d -p 9411:9411 openzipkin/zipkin
+```
+
+To kill the instance
+
+```shell
+docker container ls
+docker rm -f openzipkin/zipkin
+```
+
+<!-- TODO(issues/285): when the library in vcpkg is updated, add the screenshots
+#### Publish trace
+
+![Screenshot of the publish span in the Zipkin UI.](assets/zipkin_publish_span.png)
+
+#### Create trace
+
+![Screenshot of the create span in the Zipkin UI.](assets/zipkin_create_span.png) -->
+
+## Build and run
+
+### Using CMake and Vcpkg
+
+#### Run the publisher with Zipkin
+
+```sh
+cd cpp-samples/pubsub-open-telemetry
+cmake -DWITH_ZIPKIN=ON -S . -B .build -DCMAKE_TOOLCHAIN_FILE=$HOME/vcpkg/scripts/buildsystems/vcpkg.cmake -G Ninja
+cmake --build .build
+```
 
 #### Run basic publisher examples
 
 ```shell
-bazel run //:publisher [project-name] [topic-id]
-bazel run //:publisher -- [project-name] [topic-id] -n 1000
-bazel run //:publisher -- [project-name] [topic-id] --message_size 0
-bazel run //:publisher -- [project-name] [topic-id] --tracing-rate 0.01 -n 10
+.build/publisher_zipkin [project-name] [topic-id]
+.build/publisher_zipkin [project-name] [topic-id] -n 1000
+.build/publisher_zipkin [project-name] [topic-id] --tracing-rate 0.01 -n 10
 ```

pubsub-open-telemetry/publisher_zipkin.cc

@@ -0,0 +1,69 @@
+// Copyright 2023 Google LLC
+//
+// 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
+//
+// https://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 "google/cloud/opentelemetry/trace_exporter.h"
+#include "google/cloud/pubsub/publisher.h"
+#include "opentelemetry/exporters/zipkin/zipkin_exporter_factory.h"
+#include "opentelemetry/exporters/zipkin/zipkin_exporter_options.h"
+#include "parse_args.h"
+#include "publisher_helper.h"
+#include <opentelemetry/sdk/trace/batch_span_processor_factory.h>
+#include <opentelemetry/sdk/trace/batch_span_processor_options.h>
+#include <opentelemetry/sdk/trace/processor.h>
+#include <opentelemetry/sdk/trace/tracer_provider_factory.h>
+#include <opentelemetry/trace/provider.h>
+#include <iostream>
+
+// Create a few namespace aliases to make the code easier to read.
+namespace gc = ::google::cloud;
+namespace otel = gc::otel;
+namespace trace_sdk = ::opentelemetry::sdk::trace;
+namespace trace = ::opentelemetry::trace;
+namespace zipkin = opentelemetry::exporter::zipkin;
+
+void ConfigureZipkinTracer(ParseResult const& args) {
+  auto exporter = zipkin::ZipkinExporterFactory::Create();
+
+  trace_sdk::BatchSpanProcessorOptions span_options;
+  span_options.max_queue_size = args.max_queue_size;
+  auto processor = trace_sdk::BatchSpanProcessorFactory::Create(
+      std::move(exporter), span_options);
+  auto provider =
+      trace_sdk::TracerProviderFactory::Create(std::move(processor));
+
+  trace::Provider::SetTracerProvider(std::move(provider));
+}
+
+int main(int argc, char* argv[]) try {
+  auto args = ParseArguments(argc, argv);
+  if (args.project_id.empty() && args.topic_id.empty()) {
+    return 1;
+  }
+  std::cout << "Using project `" << args.project_id << "` and topic `"
+            << args.topic_id << "`\n";
+
+  // Automatically call `Cleanup()` before returning from `main()`.
+  std::shared_ptr<void> cleanup(nullptr, [](void*) { Cleanup(); });
+
+  ConfigureZipkinTracer(args);
+
+  auto publisher = CreatePublisher(args);
+
+  Publish(publisher, args);
+
+  return 0;
+} catch (google::cloud::Status const& status) {
+  std::cerr << "google::cloud::Status thrown: " << status << "\n";
+  return 1;
+}

pubsub-open-telemetry/vcpkg.json

@@ -12,7 +12,10 @@
       ]
     },
     {
-      "name": "opentelemetry-cpp"
+      "name": "opentelemetry-cpp",
+      "features": [
+        "zipkin"
+      ]
     },
     "boost-program-options"
   ]