Merge pull request #19 from liuhaoyang/feature/httpclient_diagnostics

Provide support for HttpClient

build/version.props

 <Project>
 	<PropertyGroup>
 		<VersionMajor>0</VersionMajor>
-		<VersionMinor>1</VersionMinor>
+		<VersionMinor>2</VersionMinor>
 		<VersionPatch>0</VersionPatch>
 		<VersionQuality></VersionQuality>
 		<VersionPrefix>$(VersionMajor).$(VersionMinor).$(VersionPatch)</VersionPrefix>

skywalking-csharp.sln

@@ -36,6 +36,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Sample.Backend",
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Sample.Frontend", "sample\SkyWalking.Sample.Frontend\SkyWalking.Sample.Frontend.csproj", "{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Diagnostics.HttpClient", "src\SkyWalking.Diagnostics.HttpClient\SkyWalking.Diagnostics.HttpClient.csproj", "{49DEFCA8-4289-4875-B6A5-35D84B3D2290}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -74,6 +76,10 @@ Global
 		{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{49DEFCA8-4289-4875-B6A5-35D84B3D2290}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -89,6 +95,7 @@ Global
 		{D75B68C5-6788-4871-A63F-F6EB48FB0DC5} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
 		{80A67B09-83F2-477F-907F-95FFF5B8FEAF} = {844CEACD-4C85-4B15-9E2B-892B01FDA4BB}
 		{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A} = {844CEACD-4C85-4B15-9E2B-892B01FDA4BB}
+		{49DEFCA8-4289-4875-B6A5-35D84B3D2290} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {94C0DA2C-CCCB-4314-93A2-9809B5DD0583}

src/SkyWalking.Abstractions/Boot/IBootService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Config/AgentConfig.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Config/CollectorConfig.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Config/DictionaryConfig.cs

 /*
-    * Licensed to the Apache Software Foundation (ASF) under one or more
-    * contributor license agreements.  See the NOTICE file distributed with
-    * this work for additional information regarding copyright ownership.
-    * The ASF licenses this file to You 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.
-    *
-    */
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ *
+ */
 
 namespace SkyWalking.Config
 {

src/SkyWalking.Abstractions/Config/RemoteDownstreamConfig.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/CarrierItem.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/IContextCarrier.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/IContextSnapshot.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/IIgnoreTracerContextListener.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/IInjectable.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/ITracerContext.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/ITracingContextListener.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Ids/DistributedTraceId.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Ids/ID.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Ids/IDistributedTraceIdCollection.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Tag/AbstractTag.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/AbstractTracingSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/ISpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/ITraceSegment.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/ITraceSegmentRef.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/IWithPeerInfo.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/LogDataEntity.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/SegmentRefType.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/SpanLayer.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Trace/StackBasedTracingSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -16,7 +16,6 @@
  *
  */
 
-
 namespace SkyWalking.Context.Trace
 {
     public abstract class StackBasedTracingSpan : AbstractTracingSpan

src/SkyWalking.Abstractions/Context/Utils/DateTimeExtensions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Utils/ExceptionExtensions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Utils/KeyValuePair.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Context/Utils/SpanLayerExtensions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.AspNetCore/Diagnostics/ITracingDiagnosticListener.cs → src/SkyWalking.Abstractions/Diagnostics/ITracingDiagnosticListener.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -16,7 +16,7 @@
  *
  */
 
-namespace SkyWalking.AspNetCore.Diagnostics
+namespace SkyWalking.Diagnostics
 {
     public interface ITracingDiagnosticListener
     {

src/SkyWalking.Abstractions/Dictionary/DictionaryUtil.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Dictionary/PossibleFound.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Abstractions/Sampling/ISampler.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.AspNetCore/Diagnostics/HostingDiagnosticListener.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -22,6 +22,7 @@ using Microsoft.Extensions.DiagnosticAdapter;
 using SkyWalking.Context;
 using SkyWalking.Context.Tag;
 using SkyWalking.Context.Trace;
+using SkyWalking.Diagnostics;
 using SkyWalking.NetworkProtocol.Trace;
 
 namespace SkyWalking.AspNetCore.Diagnostics

src/SkyWalking.AspNetCore/Extensions/ServiceCollectionExtensions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -23,6 +23,7 @@ using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Http;
 using SkyWalking.AspNetCore.Diagnostics;
+using SkyWalking.Diagnostics;
 
 namespace SkyWalking.AspNetCore
 {
@@ -55,7 +56,7 @@ namespace SkyWalking.AspNetCore
             services.AddHttpClient<TracingHttpClient>("sw-tracing");
 
             services.AddSingleton<IHostedService, SkyWalkingHostedService>();
-            services.TryAddSingleton<ITracingDiagnosticListener, HostingDiagnosticListener>();
+            services.AddSingleton<ITracingDiagnosticListener, HostingDiagnosticListener>();
             services.AddTransient<HttpMessageHandlerBuilder, TracingHttpMessageHandlerBuilder>();
             
             return services;

src/SkyWalking.AspNetCore/SkyWalking.AspNetCore.csproj

 <Project Sdk="Microsoft.NET.Sdk">
-   <Import Project="..\..\build\common.props" />
+  <Import Project="..\..\build\common.props" />
   <PropertyGroup>
     <Description>SkyWalking ASP.NET Core Agent.</Description>
     <AssemblyTitle>SkyWalking.AspNetCore</AssemblyTitle>
@@ -9,7 +9,7 @@
     <PackageTags>SkyWalking;APM</PackageTags>
     <PackageReleaseNotes>
     </PackageReleaseNotes>
-    <RootNamespace>SkyWalking</RootNamespace>
+    <RootNamespace>SkyWalking.AspNetCore</RootNamespace>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Hosting" Version="2.1.0-preview2-final" />

src/SkyWalking.AspNetCore/SkyWalkingHostedService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -23,9 +23,9 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Options;
-using SkyWalking.AspNetCore.Diagnostics;
 using SkyWalking.Boot;
 using SkyWalking.Config;
+using SkyWalking.Diagnostics;
 using SkyWalking.Remote;
 
 namespace SkyWalking.AspNetCore

src/SkyWalking.AspNetCore/SkyWalkingOptions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.AspNetCore/TracingHttpClient.cs

-using System.Net.Http;
+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ *
+ */
+
+using System.Net.Http;
 
 namespace SkyWalking.AspNetCore
 {

src/SkyWalking.AspNetCore/TracingHttpHandler.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.AspNetCore/TracingHttpMessageHandlerBuilder.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Boot/ServiceManager.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Boot/TimerService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/CarrierItemHead.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/ContextCarrier.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/ContextManager.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/ContextSnapshot.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Ids/DistributedTraceIdCollection.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Ids/GlobalIdGenerator.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Ids/NewDistributedTraceId.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Ids/PropagatedTraceId.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/IgnoredTracerContext.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -16,7 +16,6 @@
  *
  */
 
-
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using SkyWalking.Context.Trace;

src/SkyWalking.Core/Context/SW3CarrierItem.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Tag/StringTag.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Tag/Tags.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/EntrySpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/ExitSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/LocalSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -16,7 +16,6 @@
  *
  */
 
-
 namespace SkyWalking.Context.Trace
 {
     public class LocalSpan : StackBasedTracingSpan

src/SkyWalking.Core/Context/Trace/NoopExitSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/NoopSpan.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/TraceSegment.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/Trace/TraceSegmentRef.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Context/TraceContextCarrierItem.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
@@ -16,7 +16,6 @@
  *
  */
 
-
 using System;
 
 namespace SkyWalking.Context

src/SkyWalking.Core/Context/TracingContext.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Dictionary/DictionaryManager.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Dictionary/Found.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Dictionary/NetworkAddressDictionary.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Dictionary/NotFound.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Dictionary/OperationNameDictionary.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Remote/GrpcApplicationService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Remote/GrpcChannelManager.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Remote/GrpcRuntimeService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Remote/GrpcTraceSegmentService.cs

-using System.Threading;
+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ *
+ */
+
+using System.Threading;
 using System.Threading.Tasks;
 using SkyWalking.Boot;
 using SkyWalking.Context;

src/SkyWalking.Core/Sampling/SamplingService.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Utils/AtomicInteger.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Core/Utils/StackExtensions.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.Diagnostics.HttpClient/HttpClientDiagnosticListener.cs

+/*
+ * Licensed to the OpenSkywalking under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ *
+ */
+
+using System.Net.Http;
+using Microsoft.Extensions.DiagnosticAdapter;
+using SkyWalking.Context;
+using SkyWalking.Context.Tag;
+using SkyWalking.Context.Trace;
+using SkyWalking.NetworkProtocol.Trace;
+
+namespace SkyWalking.Diagnostics.HttpClient
+{
+    public class HttpClientDiagnosticListener : ITracingDiagnosticListener
+    {
+        public string ListenerName { get; } = "HttpHandlerDiagnosticListener";
+
+        [DiagnosticName("System.Net.Http.Request")]
+        public void HttpRequest(HttpRequestMessage request)
+        {
+            var contextCarrier = new ContextCarrier();
+            var peer = $"{request.RequestUri.Host}:{request.RequestUri.Port}";
+            var span = ContextManager.CreateExitSpan(request.RequestUri.ToString(), contextCarrier, peer);
+            Tags.Url.Set(span, request.RequestUri.ToString());
+            span.AsHttp();
+            span.SetComponent(ComponentsDefine.HttpClient);
+            Tags.HTTP.Method.Set(span, request.Method.ToString());
+            foreach (var item in contextCarrier.Items)
+                request.Headers.Add(item.HeadKey, item.HeadValue);
+        }
+
+        [DiagnosticName("System.Net.Http.Response")]
+        public void HttpResponse(HttpResponseMessage response)
+        {
+            var span = ContextManager.ActiveSpan;
+            if (span != null && span.IsExit)
+            {
+                Tags.StatusCode.Set(span, response.StatusCode.ToString());
+                ContextManager.StopSpan(span);
+            }        
+        }
+    }
+}
\ No newline at end of file

src/SkyWalking.Diagnostics.HttpClient/SkyWalking.Diagnostics.HttpClient.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+  <Import Project="..\..\build\common.props" />
+  <PropertyGroup>
+    <Description>SkyWalking.Diagnostics.HttpClient notifies outgoing Http requests.</Description>
+    <AssemblyTitle>SkyWalking.Diagnostics.HttpClient</AssemblyTitle>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <AssemblyName>SkyWalking.Diagnostics.HttpClient</AssemblyName>
+    <PackageId>SkyWalking.Diagnostics.HttpClient</PackageId>
+    <PackageTags>SkyWalking;APM;Diagnostics;HttpClient</PackageTags>
+    <PackageReleaseNotes>
+    </PackageReleaseNotes>
+    <RootNamespace>SkyWalking.Diagnostics.HttpClient</RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DiagnosticAdapter" Version="2.1.0-preview2-final" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\SkyWalking.Abstractions\SkyWalking.Abstractions.csproj" />
+    <ProjectReference Include="..\SkyWalking.Core\SkyWalking.Core.csproj" />
+  </ItemGroup>
+</Project>
\ No newline at end of file

src/SkyWalking.NetworkProtocol.Trace/ComponentsDefine.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.NetworkProtocol.Trace/IComponent.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0

src/SkyWalking.NetworkProtocol.Trace/OfficialComponent.cs

 /*
- * Licensed to the Apache Software Foundation (ASF) under one or more
+ * Licensed to the OpenSkywalking under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0