Route Services are often used in PCF to intercept requests to the applications and provide Authentication, Logging or other common functionality. You can read more on Route service Architecture
There are few examples in Java, Ruby, GO, and here is example implementation in .NET
One approach is to implement HttpHandler extending DelegatingHanlder and register it to process all requests:
public class ProxyHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
return ProxyRequest(request, cancellationToken);
}
}
And configure the handler to intercept requests:
// Intercepting backend calls
config.Routes.MapHttpRoute(
name: "allpath",
routeTemplate: "{*allpath}",
defaults: null,
constraints: null,
handler: new ProxyHandler()
);
// Route Static files (js,css) requests too
RouteTable.Routes.RouteExistingFiles = true;
Another possible approaches are to implement HttpModule or OWIN Middleware, or .NET Core Middleware