Serilog 和 .NET Core 2.1 HostBuilder 配置

Question

我正在使用 .NET Core 2.1 HostBuilder 类来设置和运行 GRPC 服务器，但无法正确配置 SeriLog 以便它被 .NET Core 日志管道使用以及可用（通过依赖注入) 在我的应用程序的其他地方。

class Program
{
    private static async Task Main(string[] args)
    {
        var hostBuilder = new HostBuilder()
            .ConfigureServices((hostContext, services) =>
            {
                services.AddSingleton<ILogger>(BuildLogger);

                // other services here 
            })
            .ConfigureLogging((hostContext, loggingBuilder) =>
                loggingBuilder.AddSerilog(dispose: true));

        await hostBuilder.RunConsoleAsync();
    }

    private static ILogger BuildLogger(IServiceProvider provider)
    {

        // create a (global) logger
        Log.Logger = new LoggerConfiguration() 
            ...
            .CreateLogger();

        return Log.Logger;
    }
}

问题是我需要调用loggingBuilder.AddSerilog() 来使用上面几行在DI 服务配置中注册的单例ILogger。

我意识到我可以直接调用 BuildLogger() 来获取 ILogger 实例并将该实例注册到 DI 服务配置中，但似乎我不应该这样做。我正在寻找一种方法，从.ConfigureLogging() 方法中访问ServiceProvider 实例，这样我就可以获得注册的ILogger 可能就像

serviceProvider.GetRequiredService<ILogger>();

并将其传递给AddSerilog() 调用。有什么想法吗？

Answer 1

试试现在在 Serilog 中可用的新包 - https://github.com/serilog/serilog-extensions-hosting。

  public static IHost BuildHost(string[] args) =>
    new HostBuilder()
        .ConfigureServices(services => services.AddSingleton<IHostedService, PrintTimeService>())
        .UseSerilog() // <- Add this line
        .Build();

Answer 2

我正在寻找一种方法，从 .ConfigureLogging() 方法中访问 ServiceProvider 实例，以便我可以获取已注册的 ILogger

您可以通过ILoggingBuilder.Services.BuildServiceProvider() 从ConfigureLogging() 方法中访问ServiceProvider。像这样：

//...

private static async Task Main(string[] args)
{
    var hostBuilder = new HostBuilder()
        .ConfigureServices((hostContext, services) =>
        {
            services.AddSingleton<ILogger>(BuildLogger);

            // other services here 
        })
        .ConfigureLogging((hostContext, loggingBuilder) =>
            loggingBuilder.AddSerilog(
                loggingBuilder
                    .Services.BuildServiceProvider().GetRequiredService<ILogger>(),
                dispose: true));

    await hostBuilder.RunConsoleAsync();
}

...//

Answer 3

这是一个示例，展示了如何执行此操作，包括使用 appsettings.json 配置 serilog，以及如何使用 ILogger 获取日志记录，而无需手动注入，如标记的答案所示，以及如何使用 IOptions：

    public class Settings
{
    public string Sample { get; set; }
}

public class Service : IHostedService
{
    private readonly ILogger<Service> _logger;
    private Settings _settings;
    public Service(ILogger<Service> logger,
        Settings settings)
    {
        _logger = logger;
        _settings = settings;
    }

    public Task StartAsync(CancellationToken cancellationToken)
    {
        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        return Task.CompletedTask;
    }
}

class Program
{
    static async Task Main(string[] args)
    {
        var host = new HostBuilder()
                   .ConfigureHostConfiguration(builder =>
                   {
                       builder.AddJsonFile("hostsettings.json", optional: true);
                   })
                   .ConfigureAppConfiguration((hostContext, builder) =>
                   {
                       builder.AddJsonFile("appsettings.json");
                       builder.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", optional: true);
                   })
                   .ConfigureLogging((hostContext, builder) =>
                   {
                       Log.Logger = new LoggerConfiguration()
                                    .ReadFrom.Configuration(hostContext.Configuration).CreateLogger();
                       builder.AddConfiguration(hostContext.Configuration.GetSection("Logging"));
                       builder.AddSerilog(dispose: true);
                   })
                   .ConfigureServices((hostContext, services) =>
                   {
                       var settings = hostContext.Configuration.GetSection("Configuration").Get<Settings>();
                       services.AddSingleton(settings);

                       services.AddHostedService<Service>();
                       services.AddLogging();
                       services.AddOptions();
                   })
                   .Build();

        using (host)
        {
            await host.StartAsync();
            await host.WaitForShutdownAsync();
        }
    }
}

Answer 4

根据 .NET Core 2.0+ 的 repo 文档，在提供的 loggingBuilder 上调用 AddSerilog() 并确保先配置 Serilog：

//...

private static async Task Main(string[] args) {

    Log.Logger = new LoggerConfiguration()
        //...
        .CreateLogger();

    var hostBuilder = new HostBuilder()
        .ConfigureServices((hostContext, services) => {        
            services.AddLogging(loggingBuilder =>
                loggingBuilder.AddSerilog(dispose: true));

            // other services here 
        });

    await hostBuilder.RunConsoleAsync();
}

//...

Answer 5

.Net6 中的一些变化

这是我的程序.cs

var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddSingleton<WeatherForecastService>();
Log.Logger = new LoggerConfiguration()
    .MinimumLevel.Information()
    .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
    .Enrich.FromLogContext()
    .WriteTo.Console()
    .CreateLogger(); 
builder.Host.UseSerilog( Log.Logger);
var app = builder.Build();