Logging

 # Logging

Getting started with ASP.NET Core 6 · NLog/NLog Wiki · GitHub

1. ASP.NET Core built-in logging providers

    Console
    Debug
    EventSource
    EventLog
    TraceSource
    AzureAppServicesFile
    AzureAppServicesBlob
    ApplicationInsights

2. Using NLog in ASP.NET Core
    - Install NLog.Web.AspNetCore nuget package
    - Create nlog.config file        
        <?xml version="1.0" encoding="utf-8" ?>
        <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

          <!-- the targets to write to -->
          <targets>
            <!-- write logs to file  -->
            <target name="allfile" xsi:type="File"
                    fileName="c:\DemoLogs\nlog-all-${shortdate}.log"/>
          </targets>

          <!-- rules to map from logger name to target -->
          <rules>
            <!--All logs, including from Microsoft-->
            <logger name="*" minlevel="Trace" writeTo="allfile" />
          </rules>
        </nlog>
    - Enable copy to bin folder for nlog.config
    - Enable NLog as one of the Logging Provider
        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging((hostingContext, logging) =>
            {
                logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
                logging.AddConsole();
                logging.AddDebug();
                logging.AddEventSourceLogger();
                // Enable NLog as one of the Logging Provider
                logging.AddNLog();
            })
            .UseStartup<Startup>();
            
    - If you want only NLog as the logging provider, clear all the logging providers and then add NLog.
        WebHost.CreateDefaultBuilder(args)
        .ConfigureLogging((hostingContext, logging) =>
        {
            // Remove all the default logging providers
            logging.ClearProviders();
            logging.AddConfiguration(hostingContext.Configuration.GetSection("Logging"));
            // Add NLog as the Logging Provider
            logging.AddNLog();
        })
       .UseStartup<Startup>();
    - define different logLevel for each controller
        {
          "Logging": {
            "LogLevel": {
              "Default": "Warning",
              "EmployeeManagement.Controllers.HomeController": "Trace",
              "EmployeeManagement.Models.SQLEmployeeRepository": "Error",
              "Microsoft": "Warning"
            }
          }
        }