[Worker Service] After moving to Preview 6, logging doesn't work anymore in a Windows Service

Describe the bug

After moving to .NET Core 3.0 Preview 6, my Worker Service which is installed as a Windows Service doesn’t output anymore logs in Event Viewer.

To Reproduce

Steps to reproduce the behavior:

1. Using this version of ASP.NET Core: 3.0.100-preview6-012264
2. Create a new Worker Service project in Visual Studio 2019
3. Install the following NuGet package: Microsoft.Extensions.Hosting.WindowsServices, version 3.0.0-preview6.19304.6
4. Add .UseWindowsService() in the CreateHostBuilder() method
5. From the command line, publish the project with dotnet publish to a folder (like C:\WorkerService)
6. Register it as a Windows Service by using the command sc create worker1 binPath=c:\WorkerService\WorkerService.exe
7. Run the service with sc start worker1

Expected behavior

All the logging is displayed in the Application section of the Windows logs inside Event Viewer

Additional context

With .NET Core 3.0 Preview 5, I was able to see the logging in Event Viewer just fine.

.NET Core SDK (reflecting any global.json):
 Version:   3.0.100-preview6-012264
 Commit:    be3f0c1a03

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.18362
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\3.0.100-preview6-012264\

Host (useful for support):
  Version: 3.0.0-preview6-27804-01
  Commit:  fdf81c6faf

.NET Core SDKs installed:
  2.1.600 [C:\Program Files\dotnet\sdk]
  2.1.601 [C:\Program Files\dotnet\sdk]
  2.1.602 [C:\Program Files\dotnet\sdk]
  2.1.604 [C:\Program Files\dotnet\sdk]
  2.1.700-preview-009618 [C:\Program Files\dotnet\sdk]
  2.1.700 [C:\Program Files\dotnet\sdk]
  2.1.800-preview-009677 [C:\Program Files\dotnet\sdk]
  2.1.800-preview-009696 [C:\Program Files\dotnet\sdk]
  2.2.100 [C:\Program Files\dotnet\sdk]
  3.0.100-preview6-012264 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.0-preview6.19307.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.8 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.2.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.0-preview6-27804-01 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.0.0-preview6-27804-01 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App] 

[davidfowl]

This is an unintentional side effect of fact that we add the event log provider by default now at the warning level. https://github.com/aspnet/Extensions/blob/f12d709976e382672ce100bc00381a8847f06489/src/Hosting/Hosting/src/Host.cs#L102

You can work around this by adding this entry to your configuration:

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

This turns the level for the event log provider to Information for those categories.

We may need to re-think this or possibly remove the filter when running in a windows service.

cc @Tratcher

[Tratcher]

Don’t call AddEventLog again, Configure the options in DI rather than passing them in directly: https://github.com/aspnet/Extensions/blob/46d76f9a189ee68852d136c577364b7b0955257a/src/Hosting/WindowsServices/src/WindowsServiceLifetimeHostBuilderExtensions.cs#L41-L47