README.md

NetEscapades.Extensions.Logging

NetEscapades.Extensions.Logging.RollingFile

A rolling file provider for ASP.NET Core 2.1 Microsoft.Extensions.Logging, the logging subsystem used by ASP.NET Core. Writes logs to a set of text files, one per day.

Getting Started

First Install the NetEscapades.Extensions.Logging.RollingFile package from NuGet, either using powershell:

Install-Package NetEscapades.Extensions.Logging.RollingFile

or using the .NET CLI:

dotnet add package NetEscapades.Extensions.Logging.RollingFile

Next configure the provider by calling AddFile() on an ILoggingBuilder during logger configuration in Program.cs.

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging(builder => builder.AddFile()) // <- Add this line
            .UseStartup<Startup>()
            .Build();
}

You can pass additional options to the Add File by passing an Action<FileLoggerOptions>, for example:

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging(builder => builder.AddFile(options => {
                options.FileName = "diagnostics-"; // The log file prefixes
                options.LogDirectory = "LogFiles"; // The directory to write the logs
                options.FileSizeLimit = 20 * 1024 * 1024; // The maximum log file size (20MB here)
            })) 
            .UseStartup<Startup>()
            .Build();
}

Finally The provider will create log files prefixed with the FileName, and suffixed with the current date in the yyyyMMdd format.

log-20160631.txt
log-20160701.txt
log-20160702.txt

Logs will look something like the following:

2017-09-01 18:34:18.083 +01:00 [Information] Microsoft.AspNetCore.Hosting.Internal.WebHost: Request starting HTTP/1.1 GET http://localhost:50037/api/values  
2017-09-01 18:34:18.159 +01:00 [Information] Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker: Executing action method SampleApp.Controllers.ValuesController.Get (SampleApp) with arguments ((null)) - ModelState is Valid
2017-09-01 18:34:18.161 +01:00 [Information] SampleApp.Controllers.ValuesController: Executed Get action
2017-09-01 18:34:18.165 +01:00 [Information] Microsoft.AspNetCore.Mvc.Internal.ObjectResultExecutor: Executing ObjectResult, writing value Microsoft.AspNetCore.Mvc.ControllerContext.
2017-09-01 18:34:18.192 +01:00 [Information] Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker: Executed action SampleApp.Controllers.ValuesController.Get (SampleApp) in 36.3435ms
2017-09-01 18:34:18.195 +01:00 [Information] Microsoft.AspNetCore.Hosting.Internal.WebHost: Request finished in 113.6076ms 200 application/json; charset=utf-8

Credits

This provider is heavily cribbed from the Azure App Service Logging Provider from the ASP.NET team.