In ASP.NET Core 3.x Endpoints routing, how to specify domain name?

Question

I want to be able to route to a different controller based on the domain name of the URL.

For example, when the request URL is www.domain1.com/requestpath or sub.domain1.com/requestpath, I want the routing to use Domain1Routing.

But if the request URL is www.domain2.com/requestpath or sub.domain2.com/requestpath, I want the routing to be handled by Domain2Routing.

The following code doesn't work. Do I need to specify the pattern differently? Or use different method than MapControllerRoute()?

app.UseRouting();

app.UseEndpoints(
    endpoints => {
      endpoints.MapControllerRoute(
          name: "Domain1Routing",
          pattern: "{subdomain}.domain1.com/{requestpath}",
          defaults: new { controller = "Domain1", action = "Index" }
      );
      endpoints.MapControllerRoute(
          name: "Domain2Routing",
          pattern: "{subdomain}.domain2.com/{requestpath}",
          defaults: new { controller = "Domain2", action = "Index" }
      );
    });

Answer 1

As @JeremyCaney mentioned, what worked is using the RequireHost() extension method:

app.UseRouting();

app.UseEndpoints(
    endpoints => {
      endpoints.MapControllerRoute(
          name: "Domain1Routing",
          pattern: "{*requestpath}",
          defaults: new { controller = "Domain1", action = "Index" }.RequireHost("*.domain1.com");
      );
      endpoints.MapControllerRoute(
          name: "Domain2Routing",
          pattern: "{*requestpath}",
          defaults: new { controller = "Domain2", action = "Index" }.RequireHost("*.domain2.com");
      );
    });