Merge pull request #12 from serilog/dev

2.1.0 Release

Author: nblumhardt

README.md

@@ -12,7 +12,7 @@ Install-Package Serilog.AspNetCore -DependencyVersion Highest
 Install-Package Serilog.Sinks.Console
 ```
 
-**Next**, in your application's _Program.cs_ file, configure Serilog first:
+**Next**, in your application's _Program.cs_ file, configure Serilog first.  A `try`/`catch` block will ensure any configuration issues are appropriately logged:
 
 ```csharp
 public class Program
@@ -25,25 +25,11 @@ public class Program
             .Enrich.FromLogContext()
             .WriteTo.Console()
             .CreateLogger();
-```
-
-Then, add `UseSerilog()` to the web host builder. A `try`/`catch` block will ensure any configuration issues are appropriately logged:
 
-```csharp
         try
         {
             Log.Information("Starting web host");
-
-            var host = new WebHostBuilder()
-                .UseKestrel()
-                .UseContentRoot(Directory.GetCurrentDirectory())
-                .UseIISIntegration()
-                .UseStartup<Startup>()
-                .UseSerilog() // <-- Add this line
-                .Build();
-
-            host.Run();
-
+            BuildWebHost(args).Run();
             return 0;
         }
         catch (Exception ex)
@@ -56,6 +42,16 @@ Then, add `UseSerilog()` to the web host builder. A `try`/`catch` block will ens
             Log.CloseAndFlush();
         }
     }
+```
+
+Then, add `UseSerilog()` to the web host builder in `BuildWebHost()`.
+
+```csharp    
+    public static IWebHost BuildWebHost(string[] args) =>
+        WebHost.CreateDefaultBuilder(args)
+	    .UseStartup<Startup>()
+            .UseSerilog() // <-- Add this line
+            .Build();
 }
 ```
 
@@ -83,6 +79,25 @@ That's it! With the level bumped up a little you will see log output like:
 
 Tip: to see Serilog output in the Visual Studio output window when running under IIS, select _ASP.NET Core Web Server_ from the _Show output from_ drop-down list.
 
+A more complete example, showing _appsettings.json_ configuration, can be found in [the sample project here](https://github.com/serilog/serilog-aspnetcore/tree/dev/samples/SimpleWebSample).
+
 ### Using the package
 
 With _Serilog.AspNetCore_ installed and configured, you can write log messages directly through Serilog or any `ILogger` interface injected by ASP.NET. All loggers will use the same underlying implementation, levels, and destinations.
+
+**Tip:** change the minimum level for `Microsoft` to `Warning` and plug in this [custom logging middleware](https://github.com/datalust/serilog-middleware-example/blob/master/src/Datalust.SerilogMiddlewareExample/Diagnostics/SerilogMiddleware.cs) to clean up request logging output and record more context around errors and exceptions.
+
+### Inline initialization
+
+You can alternatively configure Serilog using a delegate as shown below:
+
+```csharp
+    .UseSerilog((hostingContext, loggerConfiguration) => loggerConfiguration
+	.ReadFrom.Configuration(hostingContext.Configuration)
+	.Enrich.FromLogContext()
+	.WriteTo.Console())
+```
+
+This has the advantage of making the `hostingContext`'s `Configuration` object available for configuration of the logger, but at the expense of recording `Exception`s raised earlier in program startup.
+
+If this method is used, `Log.Logger` is assigned implicitly, and closed when the app is shut down.

serilog-aspnetcore.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26730.10
+VisualStudioVersion = 15.0.26730.12
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{A1893BD1-333D-4DFE-A0F0-DDBB2FE526E0}"
 EndProject

src/Serilog.AspNetCore/Serilog.AspNetCore.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <Description>Serilog support for ASP.NET Core logging</Description>
-    <VersionPrefix>2.0.0</VersionPrefix>
+    <VersionPrefix>2.1.0</VersionPrefix>
     <Authors>Microsoft;Serilog Contributors</Authors>
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>

src/Serilog.AspNetCore/SerilogWebHostBuilderExtensions.cs

@@ -38,7 +38,40 @@ public static IWebHostBuilder UseSerilog(this IWebHostBuilder builder, Serilog.I
         {
             if (builder == null) throw new ArgumentNullException(nameof(builder));
             builder.ConfigureServices(collection =>
-                collection.AddSingleton<ILoggerFactory>(new SerilogLoggerFactory(logger, dispose)));
+                collection.AddSingleton<ILoggerFactory>(services => new SerilogLoggerFactory(logger, dispose)));
+            return builder;
+        }
+
+        /// <summary>Sets Serilog as the logging provider.</summary>
+        /// <remarks>
+        /// A <see cref="WebHostBuilderContext"/> is supplied so that configuration and hosting information can be used.
+        /// The logger will be shut down when application services are disposed.
+        /// </remarks>
+        /// <param name="builder">The web host builder to configure.</param>
+        /// <param name="configureLogger">The delegate for configuring the <see cref="LoggerConfiguration" /> that will be used to construct a <see cref="Logger" />.</param>
+        /// <param name="preserveStaticLogger">Indicates whether to preserve the value of <see cref="Log.Logger"/>.</param>
+        /// <returns>The web host builder.</returns>
+        public static IWebHostBuilder UseSerilog(this IWebHostBuilder builder, Action<WebHostBuilderContext, LoggerConfiguration> configureLogger, bool preserveStaticLogger = false)
+        {
+            if (builder == null) throw new ArgumentNullException(nameof(builder));
+            if (configureLogger == null) throw new ArgumentNullException(nameof(configureLogger));
+            builder.ConfigureServices((context, collection) =>
+            {
+                var loggerConfiguration = new LoggerConfiguration();
+                configureLogger(context, loggerConfiguration);
+                var logger = loggerConfiguration.CreateLogger();
+                if (preserveStaticLogger)
+                {
+                    collection.AddSingleton<ILoggerFactory>(services => new SerilogLoggerFactory(logger, true));
+                }
+                else 
+                {
+                    // Passing a `null` logger to `SerilogLoggerFactory` results in disposal via
+                    // `Log.CloseAndFlush()`, which additionally replaces the static logger with a no-op.
+                    Log.Logger = logger;
+                    collection.AddSingleton<ILoggerFactory>(services => new SerilogLoggerFactory(null, true));
+                }
+            });
             return builder;
         }
     }