Jaeger - Tracing with gRPC service

要使用 Jaeger 追蹤 gRPC service 程式，可先加入 Jaeger 與 OpenTracing.Contrib.Grpc 套件。

...
    <PackageReference Include="Jaeger" Version="0.3.6" />
    <PackageReference Include="OpenTracing.Contrib.Grpc" Version="0.2.0" />
  </ItemGroup>
...

修改 Startup.ConfigureServices，加入 Jaeger tracer、註冊 GlobalTracer、設定 gRPC 攔截器。

...
services.AddGrpc(options =>
{
    var serviceName = AppDomain.CurrentDomain.FriendlyName;
    var tracer = new Tracer.Builder(serviceName)
        .WithSampler(new ConstSampler(true))
        .Build();

    GlobalTracer.Register(tracer);

    services.AddSingleton<ITracer>(tracer);

    var interceptors = options.Interceptors;
    interceptors.Add<ServerTracingInterceptor>(tracer);

    ...
});
...