How to get application settings in static classes in AspNet Core 1.1

In the web project of my application I have appsettings.json :

{
   "Foo": "Exemplo"
},

And I have a class that reflects this setting:

public class FooSettings
{
    public string Foo { get; set; }
}

In startup.cs I read and log to use via dependency injection:

public void ConfigureServices(IServiceCollection services)
{   
    ...
    services.AddOptions();
    services.Configure<FooSettings>(Configuration.GetSection("Foo")); //lê e injeta dependênc
    ...
}

Everything Ok so far. I can get an instance of FooSettings via dependency injection in builders and it works without problems.

The question is: And to get in a static class? In Asp.Net MVC 5 it was like this:

public static class Exemplo
{
    private static readonly string Foo = ConfigurationManager.AppSettings.Get("Foo");
}

The ConfigurationManager would fetch direct from web.config

How to do this in Asp.Net Core 1.1?