SimpleRequestLogger 1.1.0

SimpleRequestLogger

This package provides a small and customizable ASP.NET Core middleware for structured logging of requests using Microsoft.Extensions.Logging. The built-in request logging is a bit noisy and emits multiple events per request. With SimpleRequestLogger you can fit all the information you need in a single log entry:

// Plaintext
[21:51:46.5705 INFO] GET / responded 200 in 31 ms.

// JSON
{
    "Time": "21:51:46.5705",
    "Level": "INFO",
    "Message": "GET \/ responded 200 in 31 ms.",
    "Properties": {
        "Method": "GET",
        "Path": "\/",
        "QueryString": "",
        "StatusCode": 200,
        "ElapsedMs": 31
    }
}

Installation

You can install the NuGet package via the NuGet Package Manager inside Visual Studio or via the console:

// Package Manager Console
Install-Package SimpleRequestLogger

// .NET Core CLI
dotnet add package SimpleRequestLogger

Usage

The only thing you should do is simply add the middleware to the request pipeline.

Default configuration

By default, SimpleRequestLogger logs all requests at information log level with message template "{Method} {Path}{QueryString} responded {StatusCode} in {ElapsedMs} ms.". To use the middleware you should only add a single line:

app.UseSimpleRequestLogging();

Custom configuration

It is possible to customize the message template, to change the log level based on status code and to disable logging for specific paths.

app.UseSimpleRequestLogging(config =>
{
    config.MessageTemplate = "{Scheme} {Method} {Path} => {StatusCode}";
    config.LogLevelSelector = (statusCode) => 
        (statusCode < 400) ? LogLevel.Information : LogLevel.Error;
    config.IgnorePath("/health");
    config.IgnorePath("/static/*");
});

Properties

• Method
• Path
• QueryString
• Protocol
• Scheme
• UserAgent
• StatusCode
• ElapsedMs

Pipeline placement

You might want to consider placing SimpleRequestLogger after request-heavy middlewares like UseStaticFiles() if those requests are not interesting for you (alternatively, you might ignore those via the configuration).

If SimpleRequestLogger catches an exception, the request will be logged with a status code 500 and the exception will be rethrown. If you have an error handling middleware that alters the response status code based on exception type, you should consider adding SimpleRequestLogger before it.

Exceptions

In normal circumstances, SimpleRequestLogger should not throw exceptions when handling requests.

On startup, when the middleware is instantiated, the configuration is verified. MessageTemplate and the ignored paths are checked for validity. Additionally, it is also ensured that LogLevelSelector delegate will not throw for the standard response status codes. In case of a problem with the configuration, an InvalidOperationException is thrown.

Performance

SimpleRequestLogger adds a negligible performance overhead to every request.

Benchmarks

The scenarios are run on a test host with a single hello-world-endpoint.