index.md

This .NET package provides integration from the LaunchDarkly.Logging API that is used by the LaunchDarkly .NET SDK, Xamarin SDK, and other LaunchDarkly libraries, to the Microsoft logging framework Microsoft.Extensions.Logging.

This adapter is published as a separate NuGet package to avoid unwanted dependencies on Microsoft.Extensions.Logging in the LaunchDarkly SDKs and in applications that do not use that framework.

The LaunchDarkly.Logging package also contains a version of this adapter, Logs.CoreLogging, which was implemented only in the .NET Core target framework and always uses version 5.x of Microsoft.Extensions.Logging. LaunchDarkly.Logging.Microsoft is the more broadly compatible version of that.

Usage

The xref:LaunchDarkly.Logging.LdMicrosoftLogging adapter is provided by the NuGet package LaunchDarkly.Logging.Microsoft. Version 2.x of the package works with Microsoft.Extensions.Logging version 5.x. New versions of LaunchDarkly.Logging.Microsoft will be released as necessary to support higher versions of Microsoft.Extensions.Logging as they become available.

Like LaunchDarkly.Logging, Microsoft.Extensions.Logging is a facade that can delegate to various destinations. These are configured with the LoggerFactory or by dependency injection mechanisms that provide an ILoggerFactory.

LaunchDarkly.Logging already has adapters of its own for some of the same basic destinations that Microsoft.Extensions.Logging can write to. For instance, to send log output from LaunchDarkly components to the console, or to a file, you do not need to use Microsoft.Extensions.Logging; you can simply use the methods in LaunchDarkly.Logging.Logs. This adapter is mainly useful if you require the more advanced configuration that Microsoft.Extensions.Logging provides, or if you have an application that is already using Microsoft.Extensions.Logging.

To use the adapter:

1. Add the NuGet package LaunchDarkly.Logging.Microsoft to your project. Make sure you also have a dependency on a compatible version of Microsoft.Extensions.Logging.

2. Use the property LdMicrosoftLogging.Adapter in any LaunchDarkly library configuration that accepts a LaunchDarkly.Logging.ILogAdapter object. It requires an ILoggerFactory, which in .NET Core is often obtained by dependency injection. For instance, if you are configuring the LaunchDarkly .NET SDK in a component that uses dependency injection:

using LaunchDarkly.Logging;
using LaunchDarkly.Sdk.Server;
using Microsoft.Extensions.Logging;

public class MyApplicationComponent
{
    private LdClient ldClient;

    public MyApplicationComponent(ILoggerFactory loggerFactory)
    {
        var config = Configuration.Builder("my-sdk-key")
            .Logging(LdMicrosoftLogging.Adapter(loggerFactory))
            .Build();
        ldClient = new LdClient(config);
    }
}