How can I lower the log level of the mvc pipeline in aspnetcore?

Question

So in an ASPNETCORE 2.0 project, I added a logging provider (serilog) to the logging factory along with a console sink. It works great, however I noticed that all the framework request pipelines (like http request response) are logging every little detail as INFO.

[17:37:26 INF] Request starting HTTP/1.1 GET http://localhost:5000/test/health
[17:37:26 INF] Executing action method DAS.Gateways.Command.Api.Controllers.TestController.HealthCheck (DAS.Gateways.Command.Api) with arguments (null) - ModelState is Valid
[17:37:26 INF] Health check called.
[17:37:27 INF] Executing ObjectResult, writing value Microsoft.AspNetCore.Mvc.ControllerContext.
[17:37:27 INF] Executed action DAS.Gateways.Command.Api.Controllers.TestController.HealthCheck (DAS.Gateways.Command.Api) in 203.8825ms
[17:37:27 INF] Request finished in 343.9801ms 200 application/json; charset=utf-8
[17:38:07 INF] Request starting HTTP/1.1 GET http://localhost:5000/test/health
[17:38:07 INF] Executing action method DAS.Gateways.Command.Api.Controllers.TestController.HealthCheck (DAS.Gateways.Command.Api) with arguments (null) - ModelState is Valid
[17:38:07 INF] Health check called.
[17:38:07 INF] Executing ObjectResult, writing value Microsoft.AspNetCore.Mvc.ControllerContext.
[17:38:07 INF] Executed action DAS.Gateways.Command.Api.Controllers.TestController.HealthCheck (DAS.Gateways.Command.Api) in 53.5876ms
[17:38:07 INF] Request finished in 60.2195ms 200 application/json; charset=utf-8

Info is the minimum log level we use for production logging and we have a Loggly sink that has a 1GB/day limit so I feel like MVC logging all request information as INFO is a bit obnoxious and I'd like to lower it to DEBUG. To be clear, I don't want to raise my logging level to prevent INFO from reaching the sink, I want .Net to lower it's logging level from INFO to DEBUG.

Is this possible and how?

Answer 1

You need to use log filtering.

You can specify a minimum log level for a specific provider and category or for all providers or all categories. Any logs below the minimum level aren't passed to that provider, so they don't get displayed or stored.

Filter rules may be defined via configuration or in code. Example of how it may look in code:

    // using Serilog.Extensions.Logging;

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging(logging => 
            {
                logging.AddFilter<SerilogLoggerProvider>("Microsoft", LogLevel.Warning);
            }
            .UseStartup<Startup>()
            .Build();

Note, that AddFilter in this case applies only to Serilog log provider as we specify a provider type. If you want to define a filter for all providers, use:

logging.AddFilter("Microsoft", LogLevel.Warning);