Merge pull request #5 from bmermet/betterservicename

Set smarter default service name

Author: bmermet

src/Datadog.Tracer.IntegrationTests/SendTracesToAgent.cs

@@ -50,18 +50,13 @@ public async void MinimalSpan()
             span.Finish();
 
             // Check that the HTTP calls went as expected
-            await _httpRecorder.WaitForCompletion(2);
-            Assert.Equal(2, _httpRecorder.Requests.Count);
-            Assert.Equal(2, _httpRecorder.Responses.Count);
+            await _httpRecorder.WaitForCompletion(1);
+            Assert.Equal(1, _httpRecorder.Requests.Count);
+            Assert.Equal(1, _httpRecorder.Responses.Count);
             Assert.All(_httpRecorder.Responses, (x) => Assert.Equal(HttpStatusCode.OK, x.StatusCode));
 
             var trace = _httpRecorder.Traces.Single();
             AssertSpanEqual(span, trace.Single());
-
-            var serviceInfo = _httpRecorder.Services.Single().ServiceInfos().Single();
-            Assert.Equal(Constants.UnkownService, serviceInfo.ServiceName);
-            Assert.Equal(Constants.UnkownApp, serviceInfo.App);
-            Assert.Equal(Constants.WebAppType, serviceInfo.AppType);
         }
 
         [Fact]
@@ -81,17 +76,15 @@ public async void CustomServiceName()
             span.Finish();
 
             // Check that the HTTP calls went as expected
-            await _httpRecorder.WaitForCompletion(3);
-            Assert.Equal(3, _httpRecorder.Requests.Count);
-            Assert.Equal(3, _httpRecorder.Responses.Count);
+            await _httpRecorder.WaitForCompletion(2);
+            Assert.Equal(2, _httpRecorder.Requests.Count);
+            Assert.Equal(2, _httpRecorder.Responses.Count);
             Assert.All(_httpRecorder.Responses, (x) => Assert.Equal(HttpStatusCode.OK, x.StatusCode));
 
             var trace = _httpRecorder.Traces.Single();
             AssertSpanEqual(span, trace.Single());
 
-            var serviceInfos = _httpRecorder.Services.Select(x => x.ServiceInfos().Single()).ToList();
-            Assert.Equal(2, serviceInfos.Count);
-            var serviceInfo = serviceInfos.Single(x => x.ServiceName == ServiceName);
+            var serviceInfo = _httpRecorder.Services.Select(x => x.ServiceInfos().Single()).Single();
             Assert.Equal(ServiceName, serviceInfo.ServiceName);
             Assert.Equal(App, serviceInfo.App);
             Assert.Equal(AppType, serviceInfo.AppType);
@@ -108,9 +101,9 @@ public async void Utf8Everywhere()
             span.Finish();
 
             // Check that the HTTP calls went as expected
-            await _httpRecorder.WaitForCompletion(2);
-            Assert.Equal(2, _httpRecorder.Requests.Count);
-            Assert.Equal(2, _httpRecorder.Responses.Count);
+            await _httpRecorder.WaitForCompletion(1);
+            Assert.Equal(1, _httpRecorder.Requests.Count);
+            Assert.Equal(1, _httpRecorder.Responses.Count);
             Assert.All(_httpRecorder.Responses, (x) => Assert.Equal(HttpStatusCode.OK, x.StatusCode));
 
             var trace = _httpRecorder.Traces.Single();

src/Datadog.Tracer.Tests/TracerTests.cs

@@ -10,13 +10,6 @@ public class TracerTests
     {
         private Mock<IAgentWriter> _agentWriter = new Mock<IAgentWriter>();
 
-        [Fact]
-        public void Ctor_DefaultValues_ShouldSendDefaultServiceInfo()
-        {
-            var tracer = new Tracer(_agentWriter.Object);
-            _agentWriter.Verify(x => x.WriteServiceInfo(It.Is<ServiceInfo>(y => y.ServiceName == Constants.UnkownService && y.AppType == Constants.WebAppType && y.App == Constants.UnkownApp)), Times.Once);
-        }
-
         [Fact]
         public void BuildSpan_NoParameter_DefaultParameters()
         {
@@ -25,7 +18,7 @@ public void BuildSpan_NoParameter_DefaultParameters()
             var builder = tracer.BuildSpan("Op1");
             var span = (Span)builder.Start();
 
-            Assert.Equal(Constants.UnkownService, span.ServiceName);
+            Assert.Equal("Datadog.Tracer", span.ServiceName);
             Assert.Equal("Op1", span.OperationName);
         }
 

src/Datadog.Tracer/Tracer.cs

@@ -2,6 +2,7 @@
 using OpenTracing.Propagation;
 using System;
 using System.Collections.Generic;
+using System.Reflection;
 using System.Threading;
 
 namespace Datadog.Tracer
@@ -18,17 +19,7 @@ internal class Tracer : ITracer, IDatadogTracer
         public Tracer(IAgentWriter agentWriter, List<ServiceInfo> serviceInfo = null, string defaultServiceName = null)
         {
             _agentWriter = agentWriter;
-            // TODO:bertrand be smarter about the service name
-            _defaultServiceName = defaultServiceName ?? Constants.UnkownService;
-            if (_defaultServiceName == Constants.UnkownService)
-            {
-                _services[Constants.UnkownService] = new ServiceInfo
-                {
-                    ServiceName = Constants.UnkownService,
-                    App = Constants.UnkownApp,
-                    AppType = Constants.WebAppType,
-                };
-            }
+            _defaultServiceName = GetExecutingAssemblyName() ?? Constants.UnkownService;
             if (serviceInfo != null)
             {
                 foreach(var service in serviceInfo)
@@ -42,6 +33,19 @@ public Tracer(IAgentWriter agentWriter, List<ServiceInfo> serviceInfo = null, st
             }
         }
 
+        private string GetExecutingAssemblyName()
+        {
+            try
+            {
+                var name = Assembly.GetExecutingAssembly().GetName();
+                return name.Name;
+            }
+            catch
+            {
+                return null;
+            }
+        }
+
         public ISpanBuilder BuildSpan(string operationName)
         {
             return new SpanBuilder(this, operationName);