Add supports for CAP (#33)

* Remove unwanted package references.

* Add cap example configuration to sample project.

* Remove unwanted package references.

* Add supports project for CAP.

* Update samples.

* Removed unused tags label.

* Upgrade CAP nuget package to 2.2.2

* Remove unused tags config from processors.

sample/SkyWalking.Sample.Backend/Controllers/ValuesController.cs

@@ -14,7 +14,7 @@ namespace SkyWalking.Sample.Backend.Controllers
         [HttpGet]
         public IEnumerable<string> Get()
         {
-            return new string[] {"value1", "value2"};
+            return new string[] { "value1", "value2" };
         }
 
         // GET api/values/5
@@ -24,23 +24,5 @@ namespace SkyWalking.Sample.Backend.Controllers
             var httpClient = new HttpClient();
             return await httpClient.GetStringAsync("http://www.baidu.com");
         }
-
-        // POST api/values
-        [HttpPost]
-        public void Post([FromBody] string value)
-        {
-        }
-
-        // PUT api/values/5
-        [HttpPut("{id}")]
-        public void Put(int id, [FromBody] string value)
-        {
-        }
-
-        // DELETE api/values/5
-        [HttpDelete("{id}")]
-        public void Delete(int id)
-        {
-        }
     } 
 }
\ No newline at end of file

sample/SkyWalking.Sample.Backend/Properties/launchSettings.json

+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:5002/",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "SkyWalking.Sample.Backend": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "http://localhost:5002/"
+    }
+  }
+}
\ No newline at end of file

sample/SkyWalking.Sample.Backend/SkyWalking.Sample.Backend.csproj

@@ -2,9 +2,6 @@
   <PropertyGroup>
     <TargetFramework>netcoreapp2.0</TargetFramework>
   </PropertyGroup>
-  <ItemGroup>
-    <Folder Include="wwwroot\" />
-  </ItemGroup>
   <ItemGroup>
     <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.3" />
   </ItemGroup>

sample/SkyWalking.Sample.Backend/Startup.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
 using SkyWalking.AspNetCore;
+using SkyWalking.Diagnostics.CAP;
 
 namespace SkyWalking.Sample.Backend
 {
@@ -26,11 +21,17 @@ namespace SkyWalking.Sample.Backend
         {
             services.AddMvc();
 
+            //services.AddCap(x =>
+            //{
+            //    x.UseKafka("192.168.10.110:9092");
+            //    x.UseMySql("Server=192.168.10.110;Database=testcap;UserId=root;Password=123123;");
+            //});
+
             services.AddSkyWalking(option =>
             {
                 option.DirectServers = "localhost:11800";
                 option.ApplicationCode = "asp-net-core-backend";
-            });
+            });//.AddCap();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
@@ -42,6 +43,8 @@ namespace SkyWalking.Sample.Backend
             }
 
             app.UseMvc();
+
+           // app.UseCap();
         }
     }
 }
\ No newline at end of file

sample/SkyWalking.Sample.Frontend/Controllers/ValuesController.cs

@@ -13,32 +13,7 @@ namespace SkyWalking.Sample.Frontend.Controllers
         public async Task<IEnumerable<string>> Get()
         {
             await new HttpClient().GetAsync("http://localhost:5002/api/values");
-            return new string[] {"value1", "value2"};
-        }
-
-        // GET api/values/5
-        [HttpGet("{id}")]
-        public string Get(int id)
-        {
-            return "value";
-        }
-
-        // POST api/values
-        [HttpPost]
-        public void Post([FromBody] string value)
-        {
-        }
-
-        // PUT api/values/5
-        [HttpPut("{id}")]
-        public void Put(int id, [FromBody] string value)
-        {
-        }
-
-        // DELETE api/values/5
-        [HttpDelete("{id}")]
-        public void Delete(int id)
-        {
+            return new string[] { "value1", "value2" };
         } 
     }
 }
\ No newline at end of file

sample/SkyWalking.Sample.Frontend/Properties/launchSettings.json

+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:5001/",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "SkyWalking.Sample.Frontend": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "http://localhost:5001/"
+    }
+  }
+}
\ No newline at end of file

sample/SkyWalking.Sample.Frontend/SkyWalking.Sample.Frontend.csproj

@@ -2,9 +2,6 @@
   <PropertyGroup>
     <TargetFramework>netcoreapp2.0</TargetFramework>
   </PropertyGroup>
-  <ItemGroup>
-    <Folder Include="wwwroot\" />
-  </ItemGroup>
   <ItemGroup>
     <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.3" />
   </ItemGroup>

sample/SkyWalking.Sample.Frontend/Startup.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.Options;
 using SkyWalking.AspNetCore;
 
 namespace SkyWalking.Sample.Frontend

skywalking-csharp.sln

@@ -22,23 +22,25 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{613F0980-9
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.Core.Tests", "test\SkyWalking.Core.Tests\SkyWalking.Core.Tests.csproj", "{3915A2C2-7174-4651-A4F1-D45CD109916A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.NetworkProtocol.Trace", "src\SkyWalking.NetworkProtocol.Trace\SkyWalking.NetworkProtocol.Trace.csproj", "{50BE8184-EC7A-4257-AF54-764C0E61276F}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.NetworkProtocol.Trace", "src\SkyWalking.NetworkProtocol.Trace\SkyWalking.NetworkProtocol.Trace.csproj", "{50BE8184-EC7A-4257-AF54-764C0E61276F}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Components", "Components", "{79ED86A5-E9B9-49B2-9354-C911C079D03E}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Core", "Core", "{CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.AspNetCore", "src\SkyWalking.AspNetCore\SkyWalking.AspNetCore.csproj", "{D75B68C5-6788-4871-A63F-F6EB48FB0DC5}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.AspNetCore", "src\SkyWalking.AspNetCore\SkyWalking.AspNetCore.csproj", "{D75B68C5-6788-4871-A63F-F6EB48FB0DC5}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "sample", "sample", "{844CEACD-4C85-4B15-9E2B-892B01FDA4BB}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Sample.Backend", "sample\SkyWalking.Sample.Backend\SkyWalking.Sample.Backend.csproj", "{80A67B09-83F2-477F-907F-95FFF5B8FEAF}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.Sample.Backend", "sample\SkyWalking.Sample.Backend\SkyWalking.Sample.Backend.csproj", "{80A67B09-83F2-477F-907F-95FFF5B8FEAF}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Sample.Frontend", "sample\SkyWalking.Sample.Frontend\SkyWalking.Sample.Frontend.csproj", "{2B4E350E-A1E5-4B4A-A642-BCA6D3887E5A}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "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}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.Diagnostics.HttpClient", "src\SkyWalking.Diagnostics.HttpClient\SkyWalking.Diagnostics.HttpClient.csproj", "{49DEFCA8-4289-4875-B6A5-35D84B3D2290}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Extensions.DependencyInjection", "src\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj", "{BF5579ED-113C-4EE6-AE03-9A9CA590C924}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "SkyWalking.Extensions.DependencyInjection", "src\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj", "{BF5579ED-113C-4EE6-AE03-9A9CA590C924}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SkyWalking.Diagnostics.CAP", "src\SkyWalking.Diagnostics.CAP\SkyWalking.Diagnostics.CAP.csproj", "{55621423-19C3-4928-8B45-666FA87BF6A2}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -86,23 +88,28 @@ Global
 		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BF5579ED-113C-4EE6-AE03-9A9CA590C924}.Release|Any CPU.Build.0 = Release|Any CPU
+		{55621423-19C3-4928-8B45-666FA87BF6A2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{55621423-19C3-4928-8B45-666FA87BF6A2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{55621423-19C3-4928-8B45-666FA87BF6A2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{55621423-19C3-4928-8B45-666FA87BF6A2}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
-		{3915A2C2-7174-4651-A4F1-D45CD109916A} = {613F0980-91ED-4064-8E8C-168582EF4AD7}
-		{79ED86A5-E9B9-49B2-9354-C911C079D03E} = {05BF0D4E-C824-4EC8-8330-36C1FC49910E}
-		{CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810} = {05BF0D4E-C824-4EC8-8330-36C1FC49910E}
+		{54B9183A-928B-43E1-9851-10E2F1CCE61C} = {CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}
 		{C3860B5F-21D0-429F-8A00-B0C0F4573DF7} = {CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}
 		{FD84A10C-C962-4AEA-BA06-86F08EB048E6} = {CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}
-		{54B9183A-928B-43E1-9851-10E2F1CCE61C} = {CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}
+		{3915A2C2-7174-4651-A4F1-D45CD109916A} = {613F0980-91ED-4064-8E8C-168582EF4AD7}
 		{50BE8184-EC7A-4257-AF54-764C0E61276F} = {CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810}
+		{79ED86A5-E9B9-49B2-9354-C911C079D03E} = {05BF0D4E-C824-4EC8-8330-36C1FC49910E}
+		{CBFF7EE0-69D7-4D6A-9BBD-8E567FF4D810} = {05BF0D4E-C824-4EC8-8330-36C1FC49910E}
 		{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}
 		{BF5579ED-113C-4EE6-AE03-9A9CA590C924} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
+		{55621423-19C3-4928-8B45-666FA87BF6A2} = {79ED86A5-E9B9-49B2-9354-C911C079D03E}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {94C0DA2C-CCCB-4314-93A2-9809B5DD0583}

src/SkyWalking.Abstractions/SkyWalking.Abstractions.csproj

@@ -15,7 +15,4 @@
     <ProjectReference Include="..\SkyWalking.NetworkProtocol.Trace\SkyWalking.NetworkProtocol.Trace.csproj" />
     <ProjectReference Include="..\SkyWalking.NetworkProtocol\SkyWalking.NetworkProtocol.csproj" />
   </ItemGroup> 
-  <ItemGroup>
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
-  </ItemGroup>
 </Project>
\ No newline at end of file

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

@@ -26,39 +26,39 @@ namespace SkyWalking.Context.Tag
     {
         public static readonly StringTag Url = new StringTag("url");
 
-        /**
-         * STATUS_CODE records the http status code of the response.
-         */
+        /// <summary>
+        /// STATUS_CODE records the http status code of the response.
+        /// </summary>
         public static readonly StringTag StatusCode = new StringTag("status_code");
 
-        /**
-         * DB_TYPE records database type, such as sql, redis, cassandra and so on.
-         */
+        /// <summary>
+        /// DB_TYPE records database type, such as sql, redis, cassandra and so on.
+        /// </summary>
         public static readonly StringTag DbType = new StringTag("db.type");
 
-        /**
-         * DB_INSTANCE records database instance name.
-         */
+        /// <summary>
+        /// DB_INSTANCE records database instance name.
+        /// </summary>
         public static readonly StringTag DbInstance = new StringTag("db.instance");
 
-        /**
-         * DB_STATEMENT records the sql statement of the database access.
-         */
+        /// <summary>
+        /// DB_STATEMENT records the sql statement of the database access.
+        /// </summary>
         public static readonly StringTag DbStatement = new StringTag("db.statement");
 
-        /**
-         * DB_BIND_VARIABLES records the bind variables of sql statement.
-         */
+        /// <summary>
+        /// DB_BIND_VARIABLES records the bind variables of sql statement.
+        /// </summary>
         public static readonly StringTag DbBindVariables = new StringTag("db.bind_vars");
 
-        /**
-         * MQ_BROKER records the broker address of message-middleware
-         */
+        /// <summary>
+        /// MQ_BROKER records the broker address of message-middleware
+        /// </summary>
         public static readonly StringTag MqBorker = new StringTag("mq.broker");
 
-        /**
-         * MQ_TOPIC records the topic name of message-middleware
-         */
+        /// <summary>
+        /// MQ_TOPIC records the topic name of message-middleware
+        /// </summary>
         public static readonly StringTag MqTopic = new StringTag("mq.topic");
 
         public static class HTTP

src/SkyWalking.Core/SkyWalking.Core.csproj

@@ -15,7 +15,6 @@
     <ProjectReference Include="..\SkyWalking.Abstractions\SkyWalking.Abstractions.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
     <PackageReference Include="Nito.AsyncEx.Coordination" Version="5.0.0-pre-05" />
     <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="4.4.1" />
   </ItemGroup>

src/SkyWalking.Diagnostics.CAP/CapDiagnosticProcessor.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;
+using DotNetCore.CAP.Diagnostics;
+using DotNetCore.CAP.Infrastructure;
+using Microsoft.Extensions.DiagnosticAdapter;
+using SkyWalking.Context;
+using SkyWalking.Context.Tag;
+using SkyWalking.Context.Trace;
+using SkyWalking.NetworkProtocol.Trace;
+using CapEvents = DotNetCore.CAP.Diagnostics.CapDiagnosticListenerExtensions;
+
+
+namespace SkyWalking.Diagnostics.CAP
+{
+    /// <summary>
+    ///  Diagnostics processor for listen and process releted events of CAP.
+    /// </summary>
+    public class CapDiagnosticProcessor : ITracingDiagnosticProcessor
+    {
+        private Func<BrokerEventData, string> _brokerOperationNameResolver;
+
+        public string ListenerName => CapEvents.DiagnosticListenerName;
+
+        public Func<BrokerEventData, string> BrokerOperationNameResolver
+        {
+            get
+            {
+                return _brokerOperationNameResolver ??
+                       (_brokerOperationNameResolver = (data) => "CAP " + data.BrokerTopicName);
+            }
+            set => _brokerOperationNameResolver = value ?? throw new ArgumentNullException(nameof(BrokerOperationNameResolver));
+        }
+
+        [DiagnosticName(CapEvents.CapBeforePublish)]
+        public void CapBeforePublish(BrokerPublishEventData eventData)
+        {
+            var operationName = BrokerOperationNameResolver(eventData);
+            var contextCarrier = new ContextCarrier();
+            var peer = eventData.BrokerAddress;
+            var span = ContextManager.CreateExitSpan(operationName, contextCarrier, peer);
+            span.SetComponent(ComponentsDefine.CAP);
+            span.SetLayer(SpanLayer.MQ);
+            span.Tag(Tags.MqTopic.Key, eventData.BrokerTopicName);
+            foreach (var item in contextCarrier.Items)
+            {
+                eventData.Headers.Add(item.HeadKey, item.HeadValue);
+            }
+        }
+
+        [DiagnosticName(CapEvents.CapAfterPublish)]
+        public void CapAfterPublish(BrokerPublishEndEventData eventData)
+        {
+            ContextManager.StopSpan();
+        }
+
+        [DiagnosticName(CapEvents.CapErrorPublish)]
+        public void CapErrorPublish(BrokerPublishErrorEventData eventData)
+        {
+            var capSpan = ContextManager.ActiveSpan;
+            if (capSpan == null)
+            {
+                return;
+            }
+            capSpan.Log(eventData.Exception);
+            capSpan.ErrorOccurred();
+            ContextManager.StopSpan(capSpan);
+        }
+
+        [DiagnosticName(CapEvents.CapBeforeConsume)]
+        public void CapBeforeConsume(BrokerConsumeEventData eventData)
+        {
+            var operationName = BrokerOperationNameResolver(eventData);
+            var carrier = new ContextCarrier();
+
+            if (Helper.TryExtractTracingHeaders(eventData.BrokerTopicBody, out var headers,
+                out var removedHeadersJson))
+            {
+                eventData.Headers = headers;
+                eventData.BrokerTopicBody = removedHeadersJson;
+
+                foreach (var tracingHeader in headers)
+                {
+                    foreach (var item in carrier.Items)
+                    {
+                        if (tracingHeader.Key == item.HeadKey)
+                        {
+                            item.HeadValue = tracingHeader.Value;
+                        }
+                    }
+                }
+            }
+            var span = ContextManager.CreateEntrySpan(operationName, carrier);
+            span.SetComponent(ComponentsDefine.CAP);
+            span.SetLayer(SpanLayer.MQ);
+            span.Tag(Tags.MqTopic.Key, eventData.BrokerTopicName);
+        }
+
+        [DiagnosticName(CapEvents.CapAfterConsume)]
+        public void CapAfterConsume(BrokerConsumeEndEventData eventData)
+        {
+            var capSpan = ContextManager.ActiveSpan;
+            if (capSpan == null)
+            {
+                return;
+            }
+
+            ContextManager.StopSpan(capSpan);
+        }
+
+        [DiagnosticName(CapEvents.CapErrorConsume)]
+        public void CapErrorConsume(BrokerConsumeErrorEventData eventData)
+        {
+            var capSpan = ContextManager.ActiveSpan;
+            if (capSpan == null)
+            {
+                return;
+            }
+
+            capSpan.Log(eventData.Exception);
+            capSpan.ErrorOccurred();
+            ContextManager.StopSpan(capSpan);
+        }
+
+        [DiagnosticName(CapEvents.CapBeforeSubscriberInvoke)]
+        public void CapBeforeSubscriberInvoke(SubscriberInvokeEventData eventData)
+        {
+            var span = ContextManager.CreateLocalSpan("Subscriber invoke");
+            span.SetComponent(ComponentsDefine.CAP);
+            span.Tag("subscriber.name", eventData.MethodName);
+        }
+
+        [DiagnosticName(CapEvents.CapAfterSubscriberInvoke)]
+        public void CapAfterSubscriberInvoke(SubscriberInvokeEventData eventData)
+        {
+            ContextManager.StopSpan();
+        }
+
+        [DiagnosticName(CapEvents.CapErrorSubscriberInvoke)]
+        public void CapErrorSubscriberInvoke(SubscriberInvokeErrorEventData eventData)
+        {
+            var capSpan = ContextManager.ActiveSpan;
+            if (capSpan == null)
+            {
+                return;
+            }
+
+            capSpan.Log(eventData.Exception);
+            capSpan.ErrorOccurred();
+            ContextManager.StopSpan(capSpan);
+        }
+    }
+}

src/SkyWalking.Diagnostics.CAP/SkyWalking.Diagnostics.CAP.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <Import Project="..\..\build\common.props" />
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <Description>SkyWalking.Diagnostics.CAP notifies of CAP messages.</Description>
+    <AssemblyTitle>SkyWalking.Diagnostics.CAP</AssemblyTitle>
+    <AssemblyName>SkyWalking.Diagnostics.CAP</AssemblyName>
+    <PackageId>SkyWalking.Diagnostics.CAP</PackageId>
+    <PackageTags>SkyWalking;APM;CAP</PackageTags>
+    <RootNamespace>SkyWalking.Diagnostics.CAP</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="DotNetCore.CAP" Version="2.2.2" />
+    <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" />
+    <ProjectReference Include="..\SkyWalking.Extensions.DependencyInjection\SkyWalking.Extensions.DependencyInjection.csproj" />
+  </ItemGroup>
+
+</Project>

src/SkyWalking.Diagnostics.CAP/SkyWalkingBuilderExtensions.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;
+using Microsoft.Extensions.DependencyInjection;
+using SkyWalking.Extensions.DependencyInjection;
+
+namespace SkyWalking.Diagnostics.CAP
+{
+    public static class SkyWalkingBuilderExtensions
+    {
+        public static SkyWalkingBuilder AddCap(this SkyWalkingBuilder builder)
+        {
+            if (builder == null)
+            {
+                throw new ArgumentNullException(nameof(builder));
+            }
+
+            builder.Services.AddSingleton<ITracingDiagnosticProcessor, CapDiagnosticProcessor>();
+            
+            return builder;
+        }
+    }
+}
\ 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>
@@ -11,10 +12,11 @@
     </PackageReleaseNotes>
     <RootNamespace>SkyWalking.Diagnostics.HttpClient</RootNamespace>
   </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.DiagnosticAdapter" Version="2.1.0-preview2-final" />
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
   </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\SkyWalking.Abstractions\SkyWalking.Abstractions.csproj" />
     <ProjectReference Include="..\SkyWalking.Core\SkyWalking.Core.csproj" />

src/SkyWalking.Extensions.DependencyInjection/SkyWalking.Extensions.DependencyInjection.csproj

@@ -16,6 +16,5 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="2.0.0" />
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.NetworkProtocol.Trace/SkyWalking.NetworkProtocol.Trace.csproj

@@ -10,7 +10,4 @@
     <PackageReleaseNotes>
     </PackageReleaseNotes>
   </PropertyGroup>
-  <ItemGroup>
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
-  </ItemGroup>
 </Project>
\ No newline at end of file

src/SkyWalking.NetworkProtocol/SkyWalking.NetworkProtocol.csproj

@@ -15,6 +15,5 @@
     <PackageReference Include="Google.Protobuf.Tools" Version="3.5.1" />
     <PackageReference Include="Grpc" Version="1.9.0" />
     <PackageReference Include="Grpc.Tools" Version="1.9.0" />
-    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
   </ItemGroup>
 </Project>
\ No newline at end of file