Q:

How to access logger in ASP.NET 5

One of the suggested approaches is to use Dependency Injection to inject logger to the constructor of the class.  https://docs.asp.net/en/latest/fundamentals/logging.html
However, what if my class is not registered with DI container or I just want to create a static logger per a class.  How can I still access LoggerFactory which was configured in Startup.cs? 
This is how I would do it using nlog:
private static readonly Logger _logger = LogManager. GetCurrentClassLogger();

A:

You could define a static property in your Startup which exposes the LoggerFactory:
public class Startup
{
    public Startup(ILoggerFactory loggerFactory)
    {
        LoggerFactory = loggerFactory;
    }

    public static ILoggerFactory LoggerFactory { get; set; }

    public void ConfigureServices(IServiceCollection services)
    {
        //..
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        //..
    }
}

And then access it where you need a logger:
public class MyClass
{
    private static readonly ILogger _log = Startup. LoggerFactory. CreateLogger<MyClass>();

    //..
}

