如何为.NET Core 3.0 Worker Service设置事件日志 [英] How to setup event log for .NET Core 3.0 Worker Service

问题描述

我正在使用带有.NET Core 3.0预览版的新Worker Service应用程序模板，并尝试使用AddEventLog方法添加事件日志记录.但是，我无法通过Windows中的事件查看器"看到任何日志.

I'm working with the new Worker Service app template with .NET Core 3.0 Preview and am trying to add event logging using the AddEventLog method. However, I cannot see any of my logs via the Event Viewer in Windows.

我有一个非常简单的Worker应用程序设置，并已配置了Program.cs文件中的日志记录，如下所示:

I have a very simple Worker app setup and have configured logging in the Program.cs file as follows:

public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
    .UseWindowsService()
    .ConfigureLogging((context, logging) =>
    {
        logging.AddEventLog(new EventLogSettings()
        {
            SourceName = "MyTestSource",
            LogName = "MyTestLog"
        });
    })
    .ConfigureServices((hostContext, services) =>
    {
        services.AddHostedService<Worker>();
    });

然后我在Worker.cs文件中有一些日志记录语句，如下所示:

I then have some logging statements in the Worker.cs file as follows:

private readonly ILogger<Worker> _logger;

public Worker(ILogger<Worker> logger)
{
    _logger = logger;
}

public override async Task StartAsync(CancellationToken cancellationToken)
{
    _logger.LogInformation($"Worker started at: {DateTime.Now}");
    await base.StartAsync(cancellationToken);
}

public override async Task StopAsync(CancellationToken cancellationToken)
{
    _logger.LogInformation($"Worker stopped at: {DateTime.Now}");
    await base.StopAsync(cancellationToken);
}

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
    while (!stoppingToken.IsCancellationRequested)
    {
        _logger.LogInformation( $"Worker running at: {DateTime.Now}");
        await Task.Delay(1000, stoppingToken);
    }
}

要设置事件日志，我从提升的Powershell提示符中运行了以下命令:

To setup the event logs, I ran the following from an elevated Powershell prompt:

New-EventLog -LogName MyTestLog -Source MyTestSource

如果打开事件查看器，则可以在应用程序和服务日志"下面看到"MyTestLog".

If I open the Event Viewer I can see "MyTestLog" listed below "Applications and Services Logs".

然后，要将我的Worker设置为Windows服务，我从提升权限的命令提示符下运行了以下命令:

Then, to set up my Worker as a Windows service, I ran the following commands from an elevated command prompt:

dotnet publish -o publish(发布项目并输出到发布目录)

dotnet publish -o publish (Publishes project and outputs to publish directory)

sc create MyTestService binPath=<path to exe in publish directory>

服务已成功创建，我可以在服务"查看器应用程序中看到它.从那里，我手动启动该服务，然后在事件查看器"中返回并没有显示日志.

The service is created successfully, and I can see it in the Services viewer application. From there, I manually start the service and then check back in the Event Viewer and no logs are displayed.

我期望会有一些日志.但是，"MyTestLog"部分在事件查看器中保持空白.

I was expecting there to be some logs. However, the "MyTestLog" section remains empty in the Event Viewer.

推荐答案

因此，我能够找到报告的问题

So I was able to find the issue reported here.

从本质上讲，它可以归结为最新的.NET Core 3.0预览版中的一项更改，在该更改中，默认情况下现在按警告级别过滤事件日志.因此，您看不到任何信息日志.

Essentially it boils down to a change in the latest .NET Core 3.0 Preview where Event Logs are filtered at the warning level by default now. Thus, you cannot see any information logs.

解决方法是简单地将appsettings.json文件编辑为如下所示:

The fix was to simply edit the appsettings.json file to look like the following:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    },
    "EventLog": {
      "LogLevel": {
        "Default": "Information",
        "Microsoft.Hosting.Lifetime": "Information"
      }
    }
  }
}

这将覆盖默认设置，并允许再次查看信息日志.

This overrides the default set and allows information logs to be viewed again.

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