Add support for connection scopes if logging is enabled (#1953)

* Add support for connection scopes if logging is enabled
- Don't create a scope if logging isn't on
- Copied the pattern we use in Hosting

src/Microsoft.AspNetCore.Server.Kestrel.Core/Internal/ConnectionLogScope.cs

@@ -0,0 +1,63 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+
+namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
+{
+    public class ConnectionLogScope : IReadOnlyList<KeyValuePair<string, object>>
+    {
+        private readonly string _connectionId;
+
+        private string _cachedToString;
+
+        public ConnectionLogScope(string connectionId)
+        {
+            _connectionId = connectionId;
+        }
+
+        public KeyValuePair<string, object> this[int index]
+        {
+            get
+            {
+                if (index == 0)
+                {
+                    return new KeyValuePair<string, object>("ConnectionId", _connectionId);
+                }
+
+                throw new ArgumentOutOfRangeException(nameof(index));
+            }
+        }
+
+        public int Count => 1;
+
+        public IEnumerator<KeyValuePair<string, object>> GetEnumerator()
+        {
+            for (int i = 0; i < Count; ++i)
+            {
+                yield return this[i];
+            }
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return GetEnumerator();
+        }
+
+        public override string ToString()
+        {
+            if (_cachedToString == null)
+            {
+                _cachedToString = string.Format(
+                    CultureInfo.InvariantCulture,
+                    "ConnectionId:{0}",
+                    _connectionId);
+            }
+
+            return _cachedToString;
+        }
+    }
+}

src/Microsoft.AspNetCore.Server.Kestrel.Core/Internal/FrameConnection.cs

@@ -2,8 +2,10 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
@@ -79,10 +81,12 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
 
         public void StartRequestProcessing<TContext>(IHttpApplication<TContext> application)
         {
-            _lifetimeTask = ProcessRequestsAsync<TContext>(application);
+            _lifetimeTask = ProcessRequestsAsync(application);
         }
 
         private async Task ProcessRequestsAsync<TContext>(IHttpApplication<TContext> application)
+        {
+            using (BeginConnectionScope())
             {
                 try
                 {
@@ -147,6 +151,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
                     KestrelEventSource.Log.ConnectionStop(this);
                 }
             }
+        }
 
         internal void CreateFrame<TContext>(IHttpApplication<TContext> application, IPipeReader input, IPipe output)
         {
@@ -454,5 +459,15 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal
                 _writeTimingWrites--;
             }
         }
+
+        private IDisposable BeginConnectionScope()
+        {
+            if (Log.IsEnabled(LogLevel.Critical))
+            {
+                return Log.BeginScope(new ConnectionLogScope(ConnectionId));
+            }
+
+            return null;
+        }
     }
 }

test/Microsoft.AspNetCore.Server.Kestrel.Core.Tests/FrameConnectionTests.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Core.Adapter.Internal;
@@ -529,5 +530,26 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             Assert.True(_frameConnection.TimedOut);
             Assert.True(aborted.Wait(TimeSpan.FromSeconds(10)));
         }
+
+        [Fact]
+        public async Task StartRequestProcessingCreatesLogScopeWithConnectionId()
+        {
+            _frameConnection.StartRequestProcessing(new DummyApplication());
+
+            _frameConnection.OnConnectionClosed(ex: null);
+
+            await _frameConnection.StopAsync().TimeoutAfter(TimeSpan.FromSeconds(5));
+            
+            var scopeObjects = ((TestKestrelTrace)_frameConnectionContext.ServiceContext.Log)
+                                    .Logger
+                                    .Scopes
+                                    .OfType<IReadOnlyList<KeyValuePair<string, object>>>()
+                                    .ToList();
+
+            Assert.Equal(1, scopeObjects.Count);
+            var pairs = scopeObjects[0].ToDictionary(p => p.Key, p => p.Value);
+            Assert.True(pairs.ContainsKey("ConnectionId"));
+            Assert.Equal(_frameConnection.ConnectionId, pairs["ConnectionId"]);
+        }
     }
 }

test/shared/TestApplicationErrorLogger.cs

@@ -19,6 +19,8 @@ namespace Microsoft.AspNetCore.Testing
 
         public ConcurrentBag<LogMessage> Messages { get; } = new ConcurrentBag<LogMessage>();
 
+        public ConcurrentBag<object> Scopes { get; } = new ConcurrentBag<object>();
+
         public int TotalErrorsLogged => Messages.Count(message => message.LogLevel == LogLevel.Error);
 
         public int CriticalErrorsLogged => Messages.Count(message => message.LogLevel == LogLevel.Critical);
@@ -27,6 +29,7 @@ namespace Microsoft.AspNetCore.Testing
 
         public IDisposable BeginScope<TState>(TState state)
         {
+            Scopes.Add(state);
             return new Disposable(() => { });
         }
 

test/shared/TestServiceContext.cs

@@ -13,8 +13,12 @@ namespace Microsoft.AspNetCore.Testing
     public class TestServiceContext : ServiceContext
     {
         public TestServiceContext()
-            : this(new LoggerFactory(new[] { new KestrelTestLoggerProvider() }))
         {
+            var logger = new TestApplicationErrorLogger();
+            var kestrelTrace = new TestKestrelTrace(logger);
+            var loggerFactory = new LoggerFactory(new[] { new KestrelTestLoggerProvider(logger) });
+
+            Initialize(loggerFactory, kestrelTrace);
         }
 
         public TestServiceContext(ILoggerFactory loggerFactory)
@@ -23,6 +27,11 @@ namespace Microsoft.AspNetCore.Testing
         }
 
         public TestServiceContext(ILoggerFactory loggerFactory, IKestrelTrace kestrelTrace)
+        {
+            Initialize(loggerFactory, kestrelTrace);
+        }
+
+        private void Initialize(ILoggerFactory loggerFactory, IKestrelTrace kestrelTrace)
         {
             LoggerFactory = loggerFactory;
             Log = kestrelTrace;
@@ -37,7 +46,7 @@ namespace Microsoft.AspNetCore.Testing
             };
         }
 
-        public ILoggerFactory LoggerFactory { get; }
+        public ILoggerFactory LoggerFactory { get; set; }
 
         public string DateHeaderValue => DateHeaderValueManager.GetDateHeaderValues().String;
     }