Add OpenTelemetry to aggregator sample (#570)

Author: JamesNK

build/dependencies.props

@@ -18,6 +18,7 @@
     <NewtonsoftJsonPackageVersion>12.0.2</NewtonsoftJsonPackageVersion>
     <NunitPackageVersion>3.12.0</NunitPackageVersion>
     <Nunit3TestAdapterPackageVersion>3.13.0</Nunit3TestAdapterPackageVersion>
+    <OpenTelemetryPackageVersion>0.2.0-alpha.51</OpenTelemetryPackageVersion>
     <SystemCommandLinePackageVersion>0.3.0-alpha.19405.1</SystemCommandLinePackageVersion>
     <SystemDiagnosticsDiagnosticSourcePackageVersion>4.5.1</SystemDiagnosticsDiagnosticSourcePackageVersion>
     <SystemSecurityPrincipalWindowsPackageVersion>4.6.0</SystemSecurityPrincipalWindowsPackageVersion>

examples/Aggregator/Server/Server.csproj

@@ -10,6 +10,19 @@
     <Protobuf Include="..\Proto\count.proto" GrpcServices="Both" Link="Protos\count.proto" />
 
     <PackageReference Include="Grpc.AspNetCore" Version="$(GrpcDotNetPackageVersion)" />
+
+    <PackageReference Include="OpenTelemetry" Version="$(OpenTelemetryPackageVersion)" />
+    <PackageReference Include="OpenTelemetry.Exporter.Zipkin" Version="$(OpenTelemetryPackageVersion)" />
+    <PackageReference Include="OpenTelemetry.Collector.Dependencies" Version="$(OpenTelemetryPackageVersion)" />
+    <PackageReference Include="OpenTelemetry.Collector.AspNetCore" Version="$(OpenTelemetryPackageVersion)" />
   </ItemGroup>
+  
+  <!-- Required because the project is using a preview version of OpenTelemtry from MyGet -->
+  <PropertyGroup Label="RestoreSources">
+    <RestoreSources>
+      $(RestoreSources);
+      https://www.myget.org/F/opentelemetry/api/v3/index.json;
+    </RestoreSources>
+  </PropertyGroup>
 
 </Project>

examples/Aggregator/Server/Services/GreeterService.cs

@@ -48,7 +48,6 @@ public override async Task SayHellos(HelloRequest request, IServerStreamWriter<H
 
                 await responseStream.WriteAsync(new HelloReply { Message = message });
 
-                // Gotta look busy
                 await Task.Delay(1000);
             }
         }

examples/Aggregator/Server/Startup.OpenTelemetry.cs

@@ -0,0 +1,63 @@
+#region Copyright notice and license
+
+// Copyright 2019 The 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.
+
+#endregion
+
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using OpenTelemetry.Collector.AspNetCore;
+using OpenTelemetry.Collector.Dependencies;
+using OpenTelemetry.Exporter.Zipkin;
+using OpenTelemetry.Trace;
+using OpenTelemetry.Trace.Config;
+using OpenTelemetry.Trace.Export;
+using OpenTelemetry.Trace.Sampler;
+
+namespace Server
+{
+    public partial class Startup
+    {
+        private void ConfigureOpenTelemetryServices(IServiceCollection services)
+        {
+            services.AddSingleton<ISampler>(Samplers.AlwaysSample);
+            services.AddSingleton<ZipkinTraceExporterOptions>(_ => new ZipkinTraceExporterOptions
+            {
+                ServiceName = "aggregator",
+                Endpoint = new Uri("http://localhost:9411/api/v2/spans")
+            });
+            services.AddSingleton<SpanExporter, ZipkinTraceExporter>();
+            services.AddSingleton<SpanProcessor, BatchingSpanProcessor>();
+            services.AddSingleton<TraceConfig>();
+            services.AddSingleton<ITracer, Tracer>();
+
+            // you may also configure request and dependencies collectors
+            services.AddSingleton<RequestsCollectorOptions>(new RequestsCollectorOptions());
+            services.AddSingleton<RequestsCollector>();
+
+            services.AddSingleton<DependenciesCollectorOptions>(new DependenciesCollectorOptions());
+            services.AddSingleton<DependenciesCollector>();
+        }
+
+        public void ConfigureOpenTelemetry(IServiceProvider serviceProvider)
+        {
+            serviceProvider.GetRequiredService<ILogger<Startup>>().LogInformation("Enabling OpenTelemetry");
+
+            serviceProvider.GetRequiredService<RequestsCollector>();
+            serviceProvider.GetRequiredService<DependenciesCollector>();
+        }
+    }
+}

examples/Aggregator/Server/Startup.cs

@@ -17,23 +17,39 @@
 #endregion
 
 using System;
+using System.Diagnostics;
 using Count;
 using Greet;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 
 namespace Server
 {
-    public class Startup
+    public partial class Startup
     {
+        private readonly IConfiguration _configuration;
+        private const string EnableOpenTelemetryKey = "EnableOpenTelemetry";
+
+        public Startup(IConfiguration configuration)
+        {
+            _configuration = configuration;
+        }
+
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddGrpc();
             services.AddSingleton<IncrementingCounter>();
 
+            if (_configuration.GetValue<bool>(EnableOpenTelemetryKey))
+            {
+                ConfigureOpenTelemetryServices(services);
+            }
+
             // These clients will call back to the server
             services
                 .AddGrpcClient<Greeter.GreeterClient>((s, o) => { o.Address = GetCurrentAddress(s); })
@@ -62,6 +78,11 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 app.UseDeveloperExceptionPage();
             }
 
+            if (_configuration.GetValue<bool>(EnableOpenTelemetryKey))
+            {
+                ConfigureOpenTelemetry(app.ApplicationServices);
+            }
+
             app.UseRouting();
 
             app.UseEndpoints(endpoints =>

examples/README.md

@@ -93,8 +93,17 @@ The worker shows how a [.NET worker service](https://devblogs.microsoft.com/aspn
 
 The aggregator shows how a to make nested gRPC calls (a gRPC service calling another gRPC service). The gRPC client factory is used in ASP.NET Core to inject a client into services. The gRPC client factory is configured to propagate the context from the original call to the nested call. In this example the cancellation from the client will automatically propagate through to nested gRPC calls.
 
+The aggregator can optionally be run with [OpenTelemetry](https://github.com/open-telemetry/opentelemetry-dotnet) enabled. OpenTelemetry is configured to capture tracing information and send it to [Zipkin](https://zipkin.io), a distributed tracing system. A Zipkin server needs to be running to receive traces. The simplest way to do that is [run the Zipkin Docker image](https://zipkin.io/pages/quickstart.html).
+
+To run the aggregator server with OpenTelemetry enabled:
+
+```console
+dotnet run --EnableOpenTelemetry=true
+```
+
 ##### Scenarios:
 
 * Client factory
 * Client canceling a call
-* Cancellation propagation
+* Cancellation propagation
+* Capture tracing with [OpenTelemetry](https://github.com/open-telemetry/opentelemetry-dotnet) (optional)