Serilog

Utilisation

public sealed class MyClass { private readonly ILogger logger = Log.Logger.ForContext<MyClass>(); public void MyMethod() { logger.Verbose("message");

Sinks

Définit où les log doivent être écris.

Console

const string customTemplate = "{Timestamp:yyyy-MMM-dd HH:mm:ss} [{Level}] {Message}{NewLine}{Exception}"; Log.Logger = new LoggerConfiguration() .WriteTo.Console(outputTemplate: customTemplate) .CreateLogger();

Nuget packages: Serilog.Sinks.Console

(Rolling) File

Le fichier sera nommé file-YYYYMMDD.log.

ILogger logger = new LoggerConfiguration() .WriteTo.File( "file.log", rollOnFileSizeLimit: true, fileSizeLimitBytes: 10_000_000, // 10 MB retainedFileCountLimit: 3) // retainedFileCountLimit, max number of log files to keep .CreateLogger();

Log4net

// configure log4net XmlConfigurator.Configure(); Log.Logger = new LoggerConfiguration() .WriteTo.Log4Net(supplyContextMessage: true) .CreateLogger();

Il n'est pas possible d'utiliser les Repositories.

Application Insights

Nuget package: Serilog.Sinks.ApplicationInsights

Log.Logger = new LoggerConfiguration() .WriteTo.ApplicationInsights(TelemetryConverter.Traces) .CreateLogger();

Trace vs Event
Ne pas oublier de configurer Application Insights.

Structured data

Par défaut, Serilog gère les types suivant: bool numbers string dates nullables IEnumerable Dictionary (si la clé est type de base)
Pour les autres types, ToString est utilisé.

Log.Logger.Information("Text {NamedProperty1} {NamedProperty2}", value1, value2);

Destructured object

var user = new User { Name = "Joe", Age = 35 }; // pour éviter que ToString ne soit utilisé, ajouter un @ devant le nom Log.Logger.Information("User: {@User}", user); // User: {"Name": "Joe", "Age": 35, "$type": "User"} // configurer la déstructuration ILogger logger = new LoggerConfiguration() .Destructure.ByTransforming<User>(u => new { u.Name, u.Age }) .WriteTo.Console() .CreateLogger(); Log.Logger.Information("User: {@User}", user); // User: {"Name": "Joe", "Age": 35}

Format

Log.Logger.Information("{StringProperty}", myString); // "MyString" Log.Logger.Information("{StringProperty:l}", myString); // MyString Log.Logger.Information("{NumberProperty:0.00}", Math.PI); // 3,14

Level

Par défaut, les levels Verbose et Debug ne sont logués.

Log.Logger.Verbose("Text"); Log.Logger.Debug("Text"); Log.Logger.Information("Text"); Log.Logger.Warning("Text"); Log.Logger.Error("Text"); Log.Logger.Fatal("Text"); ILogger logger = new LoggerConfiguration() .MinimumLevel.Verbose() // définit le level minimum de log pour tous les sink .WriteTo.Console(LogEventLevel.Information) // restreint le level minimum de log pour le sink Console .CreateLogger();

Filter

Log.Logger = new LoggerConfiguration() .WriteTo.Console() .Filter.ByIncludingOnly(Matching.FromSource<Program>()) // inclus seulement les log avec un SourceContext = type Program .Filter.ByIncludingOnly(Matching.FromSource("MyNamespace")) // inclus seulement les log avec un SourceContext commençant par MyNamespace .CreateLogger(); // SourceContext Log.Logger.ForContext<Program>().Information("Text");

Event enricher

ILogger logger = new LoggerConfiguration() .Enrich.WithProperty("ApplicationName", "MyApp") .WriteTo.Console() .CreateLogger(); Log.Logger.Information("{ApplicationName} - Text"); // MyApp - Text ILogger logger = new LoggerConfiguration() .Enrich.With<MyEventEnricher>() .WriteTo.Console() .CreateLogger(); Log.Logger.Information("{ApplicationName} - {ApplicationVersion} - Text"); // MyApp - 1.0.0.0 - Text

MyEventEnricher.cs

class MyEventEnricher : ILogEventEnricher { public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory) { var applicationAssembly = Assembly.GetEntryAssembly(); var name = applicationAssembly.GetName().Name; var version = applicationAssembly.GetName().Version; logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("ApplicationName", name)); logEvent.AddPropertyIfAbsent(propertyFactory.CreateProperty("ApplicationVersion", version)); } }

Timing

NuGet package: Serilog.Extras.Timing

ASP.NET web API

Nuget packages: Serilog.AspNetCore

Program.cs

builder.Host.UseSerilog((ctx, services, config) => config.ReadFrom.Configuration(ctx.Configuration));

Dependency Injection

Utiliser plutôt Serilog.Extensions.Logging.File avec la DI par défaut fournit par Microsoft.Extensions.Logging

Program.cs

static void Main(string[] args) { Log.Logger = new LoggerConfiguration() .WriteTo.Console(outputTemplate: customTemplate) .CreateLogger(); var services = new ServiceCollection(); services.AddTransient<IMyClass, MyClass>() .AddSingleton(Log.Logger); var provider = services.BuildServiceProvider(); var myObject = provider.GetService<IMyClass>(); myObject.MyMethod();

MyClass.cs

public class MyClass : IMyClass { private readonly ILogger logger; public MyClass(ILogger logger) { this.logger = logger.ForContext<MyClass>(); } public void MyMethod() { logger.Debug("message");

Configuration file

App.config

Nuget package: Serilog.Settings.AppSettings

var logger = new LoggerConfiguration() .ReadFrom.AppSettings() .CreateLogger();

App.config

<configuration> <appSettings> <add key="serilog:minimum-level" value="Warning" /> <add key="serilog:using:Console" value="Serilog.Sinks.Console" /> <add key="serilog:write-to:Console" /> <add key="serilog:using:ApplicationInsights" value="Serilog.Sinks.ApplicationInsights" /> <add key="serilog:write-to:ApplicationInsights.telemetryConverter" value="Serilog.Sinks.ApplicationInsights.Sinks.ApplicationInsights.TelemetryConverters.TraceTelemetryConverter, Serilog.Sinks.ApplicationInsights" /> <add key="serilog:using:Log4Net" value="Serilog.Sinks.Log4Net" /> <add key="serilog:write-to:Log4Net.supplyContextMessage" value="true" /> </appSettings>

appsettings.json

Nuget package: Serilog.Settings.Configuration

var configuration = new ConfigurationBuilder() .SetBasePath(Directory.GetCurrentDirectory()) .AddJsonFile("appsettings.json") .AddJsonFile($"appsettings.{Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ?? "Production"}.json", true) .Build(); var logger = new LoggerConfiguration() .ReadFrom.Configuration(configuration) .CreateLogger();

appsettings.json

"Serilog": { "Using": [ "Serilog.Sinks.File" ], "MinimumLevel": "Error", "WriteTo": [ { "Name": "File", "Args": { "path": "logs/API.log", "rollOnFileSizeLimit": true, "fileSizeLimitBytes": 10000000, "retainedFileCountLimit": 3 } } ], "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ] }

appsettings.json

{ "Serilog": { "Using": ["Serilog.Sinks.Console"], "MinimumLevel": "Debug", "WriteTo": [ { "Name": "Console" }, { "Name": "File", "Args": { "path": "%TEMP%\\Logs\\serilog-configuration-sample.txt" } } ], "Enrich": ["FromLogContext", "WithMachineName", "WithThreadId"], "Destructure": [ { "Name": "With", "Args": { "policy": "Sample.CustomPolicy, Sample" } }, { "Name": "ToMaximumDepth", "Args": { "maximumDestructuringDepth": 4 } }, { "Name": "ToMaximumStringLength", "Args": { "maximumStringLength": 100 } }, { "Name": "ToMaximumCollectionCount", "Args": { "maximumCollectionCount": 10 } } ], "Properties": { "Application": "Sample" } } }

Debug

// afficher les infos de debug SelfLog.Enable(Console.WriteLine);