How can I log events to the Event Viewer in an ASP.NET Core Web API?

Question

I'm trying to log to the Event Viewer in an ASP.NET Core 2.1 Web API, hosted on Windows Server 2016 Standard.

I've got this in my controller:

private readonly ILogger<MyController> _logger;
private readonly MyContext _context;

public TestController(MyContext context, ILogger<MyController> logger)
{
    _context = context;
    _logger = logger;
}

But I think I'm doing something wrong in my CreateWebHostBuilder() method in Program.cs because it's not working:

I had this:

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>();

and I modified it to this:

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
            .ConfigureLogging((hostingContext, logging) =>
            {
                logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
                logging.AddEventSourceLogger();
            });

But I must be doing something wrong... Any ideas? I read here that apparently EVent Viewer logging is now baked into .Net Core 2.1 Write to EventLog in .Net Core

Looking at another example, I've added loggerFactory.AddEventLog(); to my Configure() methos in Startup.cs, but it's not finding the AddEventLog() method ('ILoggerFactory' does not contain a definition for 'AddEventLog'...) — Fabricio Rodriguez, Sep 13 '18 at 09:09

Tom Faltesek · Answer 1 · 2020-01-31T15:36:29.147

For anyone who stumbles upon this using .NET Core 2.2, the Event Log logger (from Microsoft.Extensions.Logging.EventLog) should now be added in the Program.cs:

public static void Main(string[] args)
{
    CreateWebHostBuilder(args).Build().Run();
}

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
    WebHost.CreateDefaultBuilder(args)
        .ConfigureLogging((context, logging) =>
        {
            logging.AddEventLog();
        })
        .UseStartup<Startup>();

This is noted at the bottom of the .NET Core Logging docs.

UPDATE: In case someone still lands here post .NET Core 2.2, this is still relevant for .NET Core 3.1 logging.

Note you need to add another nuget package: Microsoft.Extensions.Logging.EventLog which not included in the Microsoft.Extensions.Logging package — arik, Jul 07 '19 at 10:56

score 6 · Answer 2 · answered Sep 13 '18 at 09:16

6

Ok, I had to add Microsoft.Extensions.Logging.EventLog to the project (from Nuget).

Then, in Startup.cs:

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
   loggerFactory.AddEventLog();
}

answered Sep 13 '18 at 09:16

Fabricio Rodriguez

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Weird thing is that it works on my development machine (Windows 10) but not on my server (Windows Server 2016 Standard) :( – Fabricio Rodriguez Sep 13 '18 at 09:20
1

It's most likely a permissions or group policy problem if it works on Windows 10 and not Server 2016 – Adam Vincent Sep 13 '18 at 12:11

How can I log events to the Event Viewer in an ASP.NET Core Web API?

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