UserEnricher.cs

internal class UserEnricher : ILogEventEnricher
{
    /// <summary>
    /// The property name added to enriched log events.
    /// </summary>
    public const string UserPropertyName = "User";
    private readonly IUserFactory _userFactory;

    public UserEnricher(IUserFactory userFactory)
    {
        this._userFactory = userFactory;
    }

    /// <summary>
    /// Enrich the log event.
    /// </summary>
    /// <param name="logEvent">The log event to enrich.</param>
    /// <param name="propertyFactory">Factory for creating new properties to add to the event.</param>
    public void Enrich(LogEvent logEvent, ILogEventPropertyFactory propertyFactory)
    {
        //We don't cache this property as the value can change 
        var property = propertyFactory.CreateProperty(UserPropertyName, GetCurrentUser());
        logEvent.AddPropertyIfAbsent(property);
    }

    private string GetCurrentUser()
    {
        var currentUser = _userFactory.GetCurrentUser();

        return currentUser.Name;
    }
}